Platelet function in hairy-cell leukaemia.

A quantitative study of various aspects of platelet function was carried out in eight patients with typical hairy-cell leukaemia (HCL). In at least two patients platelet aggregation was convincingly reduced to more than one aggregating agent (ADP, adrenaline, collagen, thrombin, and ristocetin). Granular storage capacity for {(14)C} 5-HT was reduced in five of the six patients tested. The two patients with definitely abnormal aggregation had the greatest reduction in granular storage pool and the longest bleeding times of those tested but, like the other patients, they did not have a clinical haemostatic defect. It was concluded that a granular storage pool defect (SPD) was at least partly responsible for aggregation abnormalities in HCL since the platelet release reaction in response to thrombin appeared to be normal. All our patients ran a chronic course uncomplicated by any of the factors known to predispose to a platelet SPD acquired in the circulation. Although in the one patient tested before and after splenectomy there was some improvement in platelet aggregation after operation, there was no clear general relationship between defective platelet function and either previous splenectomy or platelet count. Since a direct involvement of the megakaryocytic series in the underlying cell proliferation of HCL seems unlikely, it is concluded that the platelet defect can most reasonably be attributed to the production of abnormal platelets as a result of marrow fibrosis and/or infiltration by hairy cells.


Fibrinolytic activity of tissue surfaces during surgery.

A non-invasive method has been developed for the study of tissue surface fibrinolytic activity during surgery in man. Surface exudate was collected using a filter-paper disc which was then applied directly to a fibrin plate or used to prepare a euglobulin fraction. The method detected the intraoperative increase in fibrinolytic activity. At 45 minutes from the start of surgery the increase in lytic activity for tissues was four to eight times greater than that of venous blood taken simultaneously. The technique may be used to compare regional differences in tissue fibrinolysis, to determine the effect of excess local fibrinolysis on postoperative bleeding, and to study the relation between low fibrinolytic activity and postoperative adhesion formation.


A clinical view of analytical goals in clinical biochemistry.

The analytical goals inferred desirable by a group of clinicians for the imprecisions of a wide range of analytes have been studied by survey. The goals required have not in general become more stringent in the past decade and are not as demanding as those promulgated by laboratory professionals. Clinical biochemistry laboratories can now attain analytical imprecisions which satisfy the general demands of clinicians except for analyses of calcium and of low levels of glucose. The lack of published data on analytical goals does not allow wide comparison of criteria for performance standards with the results of this study.


Serum immunoreactive trypsin concentrations in infectious and non-infectious illnesses and in juvenile diabetes.

Serum immunoreactive trypsin (SIT) concentrations were measured in 244 patients with infectious illnesses and in 281 children with diabetes of recent onset. Results were compared with reference ranges established in 107 patients with non-infectious, non-diabetic illnesses, in whom SIT concentrations were found to increase with advancing age. Reduced or undetectable concentrations of SIT were associated with diabetes in children and with a few cases of severe childhood infection. Increased SIT concentrations were associated with virologically confirmed cases of infection with mumps and Coxsackie B virus infection, and with clinical diagnoses of mumps, PUO, and meningitis in children, and with Bornholm disease, cardiac infection, and respiratory infection in adults. It is suggested that silent invasion of the exocrine pancreas with elevation of the SIT concentration may accompany infection by Coxsackie B, mumps, and, possibly, other viruses.


Plasma blood group changes in gastrointestinal tract carcinoma.

The levels of A, H, I, and i plasma antigens and of anti-B, anti-I, and anti-T antibodies were measured in 70 subjects with colonic or gastric carcinoma. These studies showed a significant increase in A plasma activity of the A subjects, and in H plasma activity of the O subjects, while 25% of the tested subjects showed increased I plasma activity. There was no difference in i plasma activity between cancer patients and healthy subjects. These results take into account the marked polymorphism acquired by neoplastic tissue, which is capable also of producing a greater quantity of antigens than that of healthy subjects. Nevertheless this heterogeneity forms a barrier to the clinical measurement of these plasma antigens for screening neoplasms. The significant fall in the amount of anti-T antibodies seemed to be secondary to the absorption of these antibodies on the surface of the tumour cells.


Transfusion requirements of adolescents with severe haemophilia A.

The transfusion requirements of 75 adolescents with severe haemophilia A were studied during the five-year period 1973-77. The annual incidence of the 4935 episodes studied increased by a factor of 2.2 while the number of transfusions rose by a factor of 2.5 and the amount of therapeutic material used during the five years of the survey increased by a factor of 2.6. A further 166 bleeds occurred during periods of prophylaxis in 1976 and 1977, which generated a 25% increase in factor VIII used during those years. The increased usage of factor VIII in the years 1976 and 1977 was thus due mainly to increased numbers of transfusions given per bleed and to the use of prophylaxis but also to a slight increase in the units of factor VIII given in each dose. Twice weekly prophylaxis reduced the bleeding frequency by 30% and resulted in an increase of about 12% in usage of factor VIII. Prophylaxis given three times weekly reduced the bleeding frequency by about 60% at the cost of an increase of 77% in therapeutic materials. Iliopsoas, retroperitoneal, and abdominal wall bleeds were the commonest bleeds needing retransfusion within 24 hours, while bleeds into the extremities of the upper and lower limbs needed least retransfusions within 24 hours. Retroperitoneal bleeds needed the most transfusions per episode followed by iliopsoas, buttock, abdominal wall, and hip joint bleeds. The transfusion requirements of bleeds below the diaphragm tended to diminish steadily the more peripheral they became. This relationship did not hold for upper limb bleeds.


Use of the ultracentrifuge vertical rotor in the detection of rubella-specific IgM on a sucrose density gradient.

A comparison was made of the performance of swing-out and vertical ultracentrifuge rotors in the detection of rubella-specific IgM on a sucrose density gradient. Tests were performed on 30 sera, of which 11 were found to contain rubella-specific IgM by both methods. The centrifugation time for the swing-out rotor was 16 hours at 35,000 rpm. This was reduced to 2 hours using the vertical rotor at 50,000 rpm. Routine use of the vertical rotor would allow a reduction in the time taken to perform the test, increase the number of sera tested each time, and reduce wear on the ultracentrifuge.


A survey of the sensitivity of fresh clinical isolates to cefuroxime and other antibiotics.

The sensitivities to cefuroxime and cephradine of potentially pathogenic bacteria isolated in two British general hospitals comprising 900 beds have been assessed. In a three-month period 2537 strains were studied; 30 microgram cefuroxime discs were used with 2511 strains, and cephradine discs of the same strength were used with 2525 strains. The organisms were also examined routinely for sensitivity to other antibiotics. Overall, 91.7% of the isolates were sensitive to cefuroxime and 85.8% were inhibited by cephradine, the differences in percentage strain susceptibility to cefuroxime and cephradine being mainly a result of the greater activity of cefuroxime against the Gram-negative bacteria. The wide antibacterial effectiveness of cefuroxime should make it a useful antibiotic for the treatment of serious infections including those conditions in which the causative organism has not been identified.


Endocarditis due to Micrococcus sedentarius incertae sedis.

The clinical and bacteriological features of a case of endocarditis are described in which a Gram-positive coccus, presently designated Micrococcus sedentarius incertae sedis, was repeatedly isolated.


Meningitis caused by Pseudomonas paucimobilis.

This appears to be the first report of meningitis due to Pseudomonas paucimobilis and the first report of a clinically significant isolate of this species in the UK. Characteristics by which the species may be recognised are given, and attention is drawn to the possible confusion of Ps. paucimobilis with other yellow-pigmented pseudomonads and Flavobacterium species.


Effects of dopaminergic blocking agents on distal colon motility.

Four different dopaminergic blocking agents were able to modify the motility of the distal colon: haloperidol, sulpiride, pimozide, and thioridazine. Haloperidol and sulpiride induced different and frequently antagonistic responses; however, the effects induced by these drugs changed depending on the preexisting pattern of motility. Intestinal tone and sigmoidal or rectal phasic activity predominance are the main factors that influence responses. Biperiden, a centrally acting anticholinergic drug, and dihydroergotamine, an antinoradrenergic drug, annulled the rebound of motility induced by sulpiride in high intestinal-tone and low intestinal-tone subjects, respectively. Our results suggest that the dopaminergic system plays a role in the distal colon motility in humans.


Effects of dimepramine fumarate on physiological and cognitive behaviors of Parkinson patients.

Nine patients 55 to 74 years old with Parkinson's disease were tested before and after treatment with 50 to 225 mg dimepramine fumarate (CIBA G-31406) for about three weeks daily in order to determine the drug's effects on electrodermal responsiveness to a series of unpredictably occurring loud sounds. Twelve control subjects were tested and retested with the same procedure. In addition, the Parkinson patients received a number of cognitive tests before and after drug treatment. Results indicated that the drug tends to decrease autonomic arousal responses as measured by resting conductance levels, number of fluctuations in skin conduction per minute, orienting response, and habituation rate. These decreases in measures of arousal generally were accompanied by lowered performance scores on several tests of memory and temporal discrimination ability.


Short-term efficacy and side effects of cloprednol in children with asthma.

Efficacy and safety of alternate-day prednisolone compared to single daily cloprednol were evaluated over a six-week period in 11 children with severe asthma requiring in-residence medical supervision and long-term corticosteroid therapy. Clinical indices of efficacy, including daily pulmonary symptom scores, number of asthma attacks, asthma severity scores, and bronchodilator usage, all favored cloprednol. Afternoon pulmonary function tests (FEV1, FVC, and PEFR) were all significantly improved during the cloprednol period. Although plasma cortisol values remained within the broad range of normal during the cloprednol period, mean values were consistent with partial pituitary-adrenal suppression similar in degree to that observed 24 hours after administration of an alternate-day program of prednisolone therapy. The results of this trial showed cloprednol in single daily doses to be more effective than prednisolone in alternate doses for the treatment of children with severe asthma.


Eosinophilic fasciitis: an early variant of scleroderma.

Eosinophilic fasciitis, originally reported as a syndrome distinct from scleroderma, appears now to be an early inflammatory variant of scleroderma. No less than one half of the cases reported as eosinophilic fasciitis have convincing features of scleroderma, including Raynaud's phenomenon, esophageal dysmotility, restrictive lung disease, diffuse hyperpigmentation, synovitis, flexion contractures, dermal sclerosis, colonic diverticula, scleroderma kidney, positive latex fixation test, and the presence of serum antinuclear antibodies (ANA). Clinical presentations of scleroderma range from isolated acrosclerosis to rapidly progressive systemic sclerosis. As clinical experience and long-term follow-up data on eosinophilic fasciitis accumulate, it appears that the syndrome may well represent another variant in the scleroderma spectrum. Reported here is a case which presented clinically and histologically as eosinophilic fasciitis, but which progressed over 3 years to diffuse, histologically confirmed scleroderma.


Cutaneous manifestations of angioimmunoblastic lymphadenopathy.

Angioimmunoblastic lymphadenopathy (AIL) is an uncommon immunoproliferative disorder with a presentation similar to malignant lymphoma but with a benign histopathologic picture. We report a case of a 49-year-old woman with AIL who manifested a pruritic maculopapular eruption as her presenting complaint and whose disease pursued an aggressive clinical course. Forty-four percent of patients with AIL experience a nonspecific dermatitis that in general is maculopapular and precedes other clinical symptoms by at least several weeks. AIL should be included in the differential diagnosis of any maculopapular eruption of unknown etiology accompanied by lymphadenopathy.


Angiokeratomas, connective tissue nevus, hemangioma.

A 7-year-old white boy had multiple angiokeratomas, connective tissue nevus of the right foot, and cavernous hemangioma with hemiatrophy of the right lower extremity. The triad of abnormalities is distinct from previously described multiple malformation syndromes.


Topical phosphonoacetic acid treatment of cutaneous herpes simplex infections in the guinea pig.

Phosphonoacetic acid (PAA) was evaluated as therapy for primary cutaneous herpes simplex virus (HSV) infections in guinea pigs. Epilated areas of skin were inoculated with HSV type 1 and treated in a blind fashion with topical PAA 2% cream or placebo cream, the initial application varying from 3 to 84 hours after inoculation. PAA applied 3 hours after inoculation aborts clinical infection. Even when applied 84 hours after inoculation (12 hours after the appearance of clinical lesions), PAA reduces the severity of primary HSV infection, and thus may be suitable for the treatment of human HSV infections.


Photoprotection by melanin--a comparison of black and Caucasian skin.

The photoprotective role of melanin was evaluated by comparing the transmission of ultraviolet (UV) radiation through skin samples of blacks and Caucasians, using both biologic and spectroscopic techniques. UVA transmission was measured using fluoranthene, which causes a phototoxic response to UVA wavelength. UVB was measured by monitoring erythema produced by either a 150-watt xenon arc or FS-20 sunlamps. It was found that on the average, five times as much ultraviolet light (UVB and UVA) reaches the upper dermis of Caucasians as reaches that of blacks. Differences in transmission between the stratum corneum of blacks and of Caucasians were far less striking. The main site of UV filtration in Caucasians is the stratum corneum, whereas in blacks it is the malpighian layers. Melanin acts as a neutral density filter, reducing all wavelengths of light equally. The superior photoprotection of black epidermis is due not only to increased melanin content but also to other factors related to packaging and distribution of melanosomes. Not only are these data consistent with epidemiologic evidence, but they also may indicate why blacks are less disposed to phototoxic drug responses as well as less susceptible to acute and chronic actinic damage.


Psoriasis improved by anthracene with near ultraviolet light.

Anthracene with near ultraviolet (UV) light (UVA, 320--400 nm) has been shown previously to inhibit epidermal deoxyribonucleic acid (DNA) synthesis and mitosis. This suggested that the combination of anthracene and UVA light could suppress the rapidly proliferating epidermis of psoriasis. In this preliminary clinical study, anthracene plus UVA light improved psoriasis as shown by thinning of plaques and decreased scale in four of five patients, with complete or almost complete clearing in two of these four patients. These findings indicate that anthracene with UVA light might be helpful in the control of psoriasis.


Immunity in wart resolution.

The involvement of the humoral and cell-mediated immune systems in the regression of wart infection has been investigated extensively in recent years. This review examines the supporting evidence for the roles of humoral and cellular immunity in wart regression and its possible implications. From the available data it does not appear that a conclusion can be drawn that only humoral or cell-mediated immunity is involved, or that both are essential, in the regression of wart infection. Studies by several investigators, however, suggest that, since agents known to stimulate the cell-mediated immune system have been reported to be followed by the successful resolution of warts, the cell-mediated immune system appears to play a critical role in wart resolution. It may be that the direction which should be taken in eradication of warts resistant to conventional modalities of treatment is one which relies upon the stimulation of the patient's immune system in a very specific manner. Probably the most efficient way to accomplish this, based on available data, would be by autogenous vaccination. Following the patient's humoral and cell-mediated immune response prior to, during, and following treatment with autogenous vaccination may help to elucidate the precise mechanism by which the successful resolution of warts occurs.


Darier's disease and Kaposi's varicelliform eruption.

Kapos's varicelliform eruption usually occurs in persons with active skin disease of various types; however, in atopic dermatitis the condition may occur when the underlying disease is inactive. Two cases of widespread herpes simplex infection associated with Darier's disease are reported. In both cases, infection occurred in the absence of preexisting Darier skin lesions. In one case there was no previous history of Darier's disease. The infection occurred in the third trimester of pregnancy, but it did not appear to affect the infant or the placenta. In the second case, the Darier's disease was in remission at the time of onset of the virus infection.


Diagnosis of human scabies by epidermal shave biopsy.

A superficial shave biopsy is described as a simple, essentially painless, more reliable method for the demonstration of the scabies mite, eggs, and feces in human skin.


Localized vulvar syringomas.

Syringomas are benign appendageal tumors with differentiation toward the intraepidermal portion of the eccrine sweat duct. A 35-year-old black woman with lesions confined to the labia majora is presented. Syringomas involving the genitalia are rare, and usually the genital tumors are part of a more generalized distribution. A review of English literature showed only four reported cases of syringomas limited to the vulva. Vulvular syringomas present as multiple, bilateral, skin-colored papules over the labia majora that may or may not be pruritic. The lesions should therefore be considered in the differential diagnosis of multiple papular lesions of the vulva and are probably more common than is generally recognized.


Erythema multiforme.

Erythema multiforme (EM) is an episodic, variable, self-limited, and often recurrent inflammatory disorder of the skin and mucous membranes. In this article a definition of EM is proposed, its known clinical and histopathologic spectrum is reviewed, an approach to diagnosis and treatment is suggested, and documented evidence regarding its etiology and pathogenesis is presented. EM would appear to be a hypersensitivity reaction to a variety of precipitating agents. It has been directly linked to Mycoplasma pneumoniae and herpes simplex virus infections and possibly is triggered by a number of other infectious agents and by certain drugs. Accumulating observations of diverse immunologic phenomena suggest an underlying immune mechanism of as yet unclear type. Future investigation should be directed toward defining diagnostic criteria, evaluating reported etiologic associations, and clarifying the immunologic basis of this complex and enigmatic disorder.


Cutaneous artifactual disease. A review, amplified by personal experience.

Cutaneous artifactual disease is part of the general syndrome of contrived disease. While classical examples are easy to recognize, it can present in unusual ways. Difficulties in recognition include the unusual doctor-patient relationship, the doctor's fear of missing organic disease, and the reality of the disease to the patient's family and the family doctor. The diagnosis depends upon finding lesions whose morphology is consistent and an emotionally immature patient, whose personality shows, or has shown, hysterical and masochistic traits. Lesions "arrive" fully developed. Once there they begin to heal, so that a continuous supply of new ones is necessary if the illness is to continue. High intelligence is compatible with the diagnosis, but a mature personality is not. The differential diagnosis is extensive. Investigations prove negative or equivocal; in the latter case, the investigator is led even further into unfamiliar territory. It is suggested that the essence of management is to keep in contact with the patient.


Annular elastolytic giant cell granuloma. A clinicopathologic study of five cases and a review of similar entities.

Five patients with annular lesions of the face, scalp, and other exposed surfaces were studied using the radial triple zone biopsy technic. Interestingly, one of the patients had necrobiosis lipoidica diabeticorum (NLD) and another had systemic sarcoidosis. Clinically, the lesions were annular patches with erythematous borders and hypopigmented centers. The histopathology of the lesions showed many multinucleated giant cells, (often with prominent asteroid bodies), histiocytes, lymphocytes, scattered epithelioid cells, total lysis of elastic tissue, no necrobiosis, and absence of both mucin and lipid. This entity can be differentiated from granuloma annulare (GA), NLD, and cutaneous sarcoidosis. It is identical with several previously described entities; we propose a more appropriate term: "annular elastolytic giant cell granuloma (AEGCG)."


Melanocyte changes following PUVA therapy.

The effect of psoralens and long-wave ultraviolet light (PUVA) therapy on human melanocytes was studied at the ultrastructural level. The results demonstrate an increase in the number of melanocytes, a change in their location, and an increase in the size of the melanosomes. Significantly, some of the melanocytes extend in narrow columns deep into the dermis, limited by the basal lamina, while others are found free within the dermis. Other morphologic alterations in the melanocytes consist of abnormal mitochondria, a swollen and distorted endoplasmic reticulum, and large lysosomes. The aforementioned abnormalities were also present in PUVA-treated skin that was examined 15 months after the treatment had been stopped.


Mycosis fungoides: a retrospective study.

The clinical course of ninety patients with the histopathologic diagnosis of mycosis fungoides is reviewed. An attempt is made to correlate sex, age, of onset, lesion type, and form of therapy with outcome of the disease. The data indicate that mycosis fungoides affects predominantly middle-aged males. Patients developing tumors or erythroderma in middle age or later tend to have a shorter survival. More aggressive therapy is associated with shortened survival. Most deaths were due to unknown or unrelated processes and therapeutic complications. The data support the theory that mycosis fungoides can be a relatively nonaggressive cutaneous lymphoma. In an attempt to treat aggressively, we may be exposing patients to increased mortality.


Neonatal lupus erythematosus.

The infant of a mother with systemic lupus erythematosus (SLE) developed an extensive cutaneous eruption at 5 weeks of age. Biopsy findings were consistent with cutaneous lupus erythematosus (LE). Splenomegaly, anemia, neutropenia, and depressed total hemolytic complemtnt levels were additional findings. The course was benign, and all manifestations disappeared by 4 months of age. Fifty-two previously reported infants with cutaneous lesions, congenital atrioventricular heart block, or hematologic manifestations of neonatal LE are reviewed.


Erythermalgia with vasculitis: a review.

Erythermalgia is a condition of the extremities characterized by redness, increased temperature, and burning pain. A case of erythermalgia and coincident vasculitis of the feet is reported. The literature on the subject is reviewed, and a possible mechanism of pathogenesis is discussed.


DermRx. An experiment in computerizing information on dermatologic therapy.

The Task Force for Creating a Biomedical Communications System for Dermatology was commissioned by the American Academy of Dermatology to develop an experimental segment of a computerized data bank on dermatologic therapy. The Task Force has completed such a "first generation" system and has named it DermRx. Its data bank carries the following information on each entry: the name of the disease; topical, systemic, physical, and other kinds of treatment; caveats; references to the literature; and the date and reviewer(s). The DermLit and DermRx programs are two components of a projected broader concept of an eventual comprehensive Biomedical Communications System for Dermatology. Such a system is envisaged as a means of making available to dermatologists diverse data relevant to practice, teaching, research, and business aspects of the specialty. At the moment, access to the stored information on dermatologic literature and therapy is by telephone call to, or by correspondence with, the central computer facility at Northwestern University. Eventually it is projected to be accessible by dedicated microcomputers housed in the physician's office. This preliminary report on DermRx is presented to review the progress of the project to date and to elicit comment upon its structure and value.


Effects of prior exposure on conditioned taste aversion in the rat: androgen- and estrogen-dependent events.

The effects of preexposure and gonadal hormone manipulation on the extinction of a conditioned taste aversion were investigated. In Experiment 1, male rats were given one prior exposure to sucrose at some selected time (Days 4, 2, or 1) before a second exposure (Day 0) to sucrose and an LiCl injection. Controls received no prior exposure to sucrose but experienced only the sucrose + LiCl condition (Day 0). under the single exposure condition (Day 0) castrated animals extinguished the aversion faster than either testosterone-treated castrated rats or sham-operated rats. Sham-operated and castrated rats that had received preexposure treatment (Days 4, 2, or 1) were not distinguishable on a within-groups comparison of behavior but differed from their respective controls by exhibiting faster rates of extinction. However, in the testosterone-treated group only the Day 4 preexposure group exhibited a faster extinction rate. In Experiment 2, estradiol, dihydrotestosterone, and testosterone were studied by using only a Day 1 preexposure condition. The testosterone-treated group maintained the aversion for the longest period of time, followed by dihydrotestosterone-treated, sham, castrated, and estradiol-treated groups. It appears that estradiol augments the castration effect whereas dihydrotestosterone attenuates the effect. In Experiment 3, estradiol was administered alone or in combination with two different doses of dihydrotestosterone, and a Day 1 preexposure condition was used. The findings indicate that the outcome of behavior is dependent on the ratio of estradiol to dihydrotestosterone, with variations in this ratio resulting in fast (estrogen effect) to slow (androgen effect) rates of extinction.


Contribution of growth, fatness, and activity to weight disturbance after septohypothalamic cuts in adult hamsters.

The mechanism responsible for weight stability in adult hamsters was investigated by (a) transecting the dorsoventrally oriented nerve pathways between the septal area and hypothalamus (SH cuts) and (b) partitioning the observed increases in the rate of weight gain into three contributory components: changes in somatic growth, in body fatness, and in energy expended as voluntary activity on horizontal disks. Between 60% and 70% of the weight increase after SH cuts was due to acquisition of lean body mass, and 30%-40% of weight increase consisted of excess body fat. After SH cuts, serum growth hormone and insulin concentrations were increased on Day 14, food intake was increased between Day 2 and Day 42, skeletal lengths were greater on Day 77, and voluntary activity levels were 84% lower on Days 10-45, relative to control hamsters. It is concluded that dorsoventrally oriented nerve pathways in the septal area are involved in the control of growth, maintenance of body fat reserves, and voluntary activity and that they contribute to the maintenance of stable body weight in adult hamsters.


Temporal integration of acoustic stimulation obtained in reflex inhibition in rats and humans.

An acoustic stimulus (S1) presented just before reflex elicitation inhibits reflex expression. The present studies questioned whether inhibition provided by initial stimuli of various durations conforms to established temporal integration functions. Initial stimuli were noise bursts varying in duration (2, 20, or 200 msec) and intensity (55 or 85 dB). Eliciting stimuli (S2) for rats were intense tone bursts, which elicited the acoustic startle reflex, and for humans electrotactile stimuli to the forehead, which elicited the eye blink. Findings revealed that inhibition was greater with the 85-dB S1 stimulus and increased linearly with log increases in duration. These latter data suggest that the acoustic substrate for reflex inhibition has a long-time constant. There was one exception to this general finding. For seven (of nine) human subjects, inhibition declined when the duration of the 85-dB S1 was increased from 20 to 200 msec. Postexperimental questioning and video monitoring suggest that this anomaly resulted from a reflex enhancing arousal process.


Schedule-induced polydipsia suppresses pituitary-adrenal activity in rats.

The effects of schedule-induced polydipsia (SIP) on pituitary-adrenal activity, as indicated by plasma levels of corticosterone, were examined in a series of experiments. Male (Experiments 1 and 3) and female (Experiment 2) rats were reduced to 80% of their free-feeding weight and given daily sessions on an intermittent-feeding schedule (fixed time of 60 sec). Half of the subjects in each experiment had water available during experimental sessions and the other half did not. Animals with water available in the experimental chamber exhibited SIP in all three experiments. In Experiment 1, blood samples were collected following (a) food consumption in the home cage, (b) a session on FT 60 sec, and (c) a session with pellets available in a cup in the experimental chamber. In Experiment 2, blood samples were taken prior to and following an FT 60-sec session, and following a session with pellets available in a cup in the chamber. In Experiment 3, pre- and postsession samples were obtained as in Experiment 2 (Part A). Subsequently, the opportunity to drink during sessions was removed, and the effect on corticoids was examined (Part B). The results indicate that (a) schedule-induced drinking suppresses pituitary-adrenal activity, (b) corticoid suppression may become a conditioned response to drinking in the chamber, and (c) corticoids return to presession levels following removal of water from the chamber. In view of these findings, it is hypothesized that SIP may serve an arousal-reducing role in intermittent-feeding situations.


Sagittal and coronal image reconstruction: application in pancreatic computed tomography.

The application of coronal and sagittal image reconstruction in the display of the normal pancreas and peripancreatic region is illustrated. The use of standard reproducible reference points for multiplanar reconstruction is suggested. Reconstruction computed tomography displays more anatomic structures in the coronal and sagittal planes than ultrasonography and accurately displays the craniocaudad extent of pancreatic pathology.


Contrast enhancement of the pancreas in computed tomography.

Contrast enhancement of pancreas, liver, kidney, muscle, and blood was measured from computed tomography scans of 46 patients, including patients with normal pancreas (20), pancreatitis (20), and pancreatic carcinoma (6). A bolus injection of contrast agent was given intravenously. Contrast enhancement and contrast distribution volume in a single scan of the pancreas were measured at 40 sec and at 2, 5, and 15 min after the injection. There was a slight delay in the uptake of contrast material by pancreatic tissue if the disease was severe. In all other aspects, the pattern of contrast enhancement was equal in various patient groups and included great individual variations. Visually, the contrast agent distribution in severe pancreatitis was uneven. In severe pancreatitis, edema was seen both in the pancreas and surrounding tissues. It is concluded that gross anatomic changes and visual estimation are the only means of studying pancreatic pathology with an 18 sec scan time, and that contrast enhancement in such a study provides little additional diagnostic information.


Intravenous pancreaticography in computed tomography.

Intense pancreatic enhancement on computed tomography seems to be possible by the intravenous bolus injection technique. Despite a rather limited experience, promising clinical results have been obtained in the study of pancreatic disease, mainly concerning some aspects of acute and chronic inflammation and tumoral pathology.


Pulmonary tissue attenuation with computed tomography: comparison of inspiration and expiration scans.

Mean lung attenuation has been measured on computed tomography (CT) sections through lung bases of 17 patients with no evidence of respiratory disease. Sections were obtained in inspiration and at neutral respiration together with spirometric measurement of lung volume changes. The normal range for mean attenuation including all phases of respiration is approximately -350 to -430 EMI units (EU) (air = -500). The range is narrower on inspiration than at neutral respiration. Mean attenuation in the posterior one-third of the lung base may be 100 EU greater than in the anterior one-third. This gradient is reduced but not abolished on inspiration. Reduction of attenuation with inspiration correlates inversely with increased lung volume and cross-sectional area. Anteroposterior attenuation gradients and regional changes of attenuation with breathing can be explained by preferential ventilation and perfusion of the dependent regions of the lung. When using CT to measure lung "density," the effects of breathing should be taken into account. The relevance of these observations to the detection of early diffuse lung disease is discussed.


Dynamic computed tomography of the lung: regional ventilation measurements.

The spatial resolution provided by computed tomography (CT) yields excellent anatomic specificity, and fast scanners are capable of the serial imaging necessary to monitor rapid changes in tracer concentration over time. In this study, sequential CT imaging defined the temporal changes of xenon concentration in peripheral lung tissue of a nonhuman primate and three sheep, both during and after xenon inhalation. Ventilation rate constants (K) in lung tissue with normal and impaired function in the evaluation of regional ventilation using xenon enhanced CT are discussed.


Computed tomography in pulmonary sarcoidosis.

A group of 34 proven cases of pulmonary sarcoidosis was investigated by computed tomography (CT) to determine whether CT provided any information beyond that obtained from conventional chest films. Computed tomography disclosed a surprisingly high prevalence of minor pleural changes in sarcoidosis, including two patients with small pleural effusions. Unsuspected bullae and isolated "granulomatous" nodules were additionally demonstrated. Increases in lung density and alterations in gravity dependent vascular perfusion were assessed; these may reflect alterations in the vascular bed, and the increased density is possibly due to diffuse invasion of the lung not recognizable by conventional chest X-ray films. Tracheal compression was noted in one case and vertebral densities in three. Prominence of "small air spaces" was recorded in four patients; the nature of the pathology responsible for this finding is at present speculative. While not replacing conventional chest radiography, CT does make a definite contribution to the assessment of pulmonary sarcoidosis.


Computed tomography in the evaluation of renal lymphoma.

Four patients with renal lymphoma were evaluated by computed tomography and presented the following different manifestations: (a) multiple large and small nodules infiltrating each kidney; (b) a single large renal mass extending into the perirenal space; (c) diffuse infiltration of both kidneys; and (d) lesion of the renal hilus encasing the renal pelvis and proximal ureter of one kidney. Computed tomography is a sensitive, noninvasive imaging modality that should be performed early in the course of disease in patients with known or suspected lymphoma.


Retrorenal cysts.

Three patients are presented in whom computed tomography incidentally demonstrated low density masses posterior to, but separate from, the right kidney. In two, these were proven to represent unilocular cysts, and the third is presumed cystic. Possible etiologies are discussed.


Computed tomography in aneurysms of the vein of Galen.

Two cases of aneurysm of the great vein of Galen are reported. Diagnosis was made by means of computed tomography (CT) and confirmed by angiography. Surgical treatment was successful in one case; surgery was refused in the other case. The value of CT in the diagnosis of these malformations is stressed.


Oligodendrogliomas: CT patterns with emphasis on features indicating malignancy.

Computed tomography (CT) of 22 patients with histologically verified oligodendroglioma showed calcifications in 20 cases and contrast enhancement in 14. All of the enhancing cases proved to have malignant histological features. In 2 of the 14 malignant tumors, definite CT evidence (fluid-fluid level) of a cystic component was present.


Angiographic findings in subdural hematoma correlated with CT attenuation values.

Twenty-eight subdural hematomas in 24 patients were examined by angiography and computed tomography (CT). The angiographic appearance of the hematomas was classified as either crescentic, lentiform, or transitional. The attenuation value of the hematomas was calculated from the CT scans. The mean attenuation of crescentic hematomas (13.8 EMI units--EU: 500 scale) was considerably lower than those of lentiform (21.7 EU) and transitional (19.8 EU) hematomas. The crescentic and transitional hematomas were either subacute or chronic, the chronic crescentic hematomas having an attenuation value at or around serum level. The lentiform hematomas were all more than 24 days old. The relatively high attenuation in chronic lentiform and transitional hematomas was probably caused by rebleeding, and the shape indicates enlargement of the hematomas after membrane formation has occurred. In the chronic, low attenuation crescentic hematomas, no recent bleed and no enlargement had occurred.


Tomographic reconstruction from limited angular data.

The nth moment of a projection Mn(phi) = rnp(r, phi) dr must be a trigonometric polynomial of degree less than or equal to n. Measuring Mn(phi i) for n + 1 arbitrary angles phi i allows reconstruction of Mn(phi) for all phi. Thus in principle, the exact knowledge of the shadow function within an arbitrarily narrow sector allows reconstruction of the complete shadow. The algorithm doing this is very simple, but its applicability is severely limited by noise in the data.


Intraventricular hemorrhage in pituitary apoplexy.

A case of pituitary apoplexy is presented with previously unreported computed tomographic findings of intraventricular hemorrhage. Because of the successful use of new microsurgical techniques for the treatment of pituitary apoplexy even in patients with poor clinical status, it is important to differentiate the various causes of intraventricular hemorrhage by aggressive evaluation.


Intracranial air bubbles localizing cerebrospinal fluid fistula.

A case of persistent meningitis following excision of a jugular foramen neurinoma is presented. A cerebrospinal fluid fistula at the mastoid region was localized by computed tomographic demonstration of air bubbles in the posterior fossa.


Computed tomography of a carotid body tumor.

A patient with a carotid body tumor was evaluated by computed tomography. The tumor demonstrated an enhanced rim and a central lower density. This corresponds to the "eggshell" appearance described angiographically in carotid body tumors.


Computed tomography in craniopagus occipitalis twins.

Cranial computed tomography in the evaluation of possible surgical separation in a case of craniopagus occipitalis twins demonstrated the relationship between certain intracranial structures. Computed tomography appears to be a simple, useful diagnostic procedure to such evaluation.


CT demonstration of gas formation after renal tumor embolization.

Computed tomography findings in a case of embolized renal tumor are reported. Intratumoral gas appearing after embolization can easily be demonstrated by this imaging method.


Noninflammatory gas formation following embolization of adrenal carcinoma.

Gas formation as a result of transcatheter tumor embolization has recently been observed by conventional radiography. We report the computed tomography identification of similar benign gas formation following transcatheter embolization of a large adrenal carcinoma. Computed tomography should be the most sensitive method available for detecting gas formation. It is important to recognize this gas formation as a consequence of embolization and cell necrosis rather than as an indication of an inflammatory complication.


A technique for simultaneous dual energy scanning.

A method of deriving simultaneous dual energy scans on a conventional EMI CT5005 scanner is described. The only change that has to be made to the scanner involves the detector collimator where alternate slits are covered by a thin metal foil. The detector readings from the covered and uncovered slits are separated by software before picture processing to give two pictures from one scan--one at the usual X-ray energy and the other at a higher X-ray energy due to the beam hardening produced by the foil. A procedure is then outlined for converting these into pictures showing the effective electron density and the effective atomic number for the whole scan field.


Degradation of ascorbic acid (vitamin C) in iron-supplemented cows' milk.

The fate of [6-carbon-14] ascorbic acid in iron-supplemented and unsupplemented raw milk was studied by anion-exchange chromatography, which permitted quantitative analysis of the conversion of ascorbate to dehydroascorbate and diketogulonate as a function of time. Iron catalyzed an increase in the rate of autoxidation of ascorbate to dehydroascorbate but did not alter the equilibrium concentrations of ascorbate, dehydroascorbate, and diketogulonate. The conversion of ascorbate to dehydroascorbate and of dehydroascorbate to diketogulonate occurred rapidly even in unsupplemented milk. Thus, trace metal supplementation may not affect materially the vitamin C content of stored milk.


25-hydroxyvitamin D in plasma of cattle.

Blood samples from 12 Shorthorn heifers, fed a grass silage ration and housed indoors or outdoors, were assayed for 25-hydroxyvitamin D during 9 mo. There was more in plasma during the summer from the outdoor group, reflecting a greater exposure to ultraviolet light and dermal synthesis of vitamin D, the precursor of 25-hydroxyvitamin D. In another experiment, assays were in four groups of six heifers each; 1) control, 2) single oral dose of 1,000,000 IU vitamin D3, 3) injected intramuscularly with 1,000,000 IU of vitamin D3, and 4) free access to a mineral mixture containing 32,000 IU vitamin D3/kg. In all groups, 25-hydroxyvitamin D was higher in plasma in summer than in winter. All heifers given vitamin D had more 25-hydroxyvitamin D in plasma during winter than controls. Animals injected with vitamin D had more 25-hydroxyvitamin D in plasma during part of the winter than those on the other treatments with vitamin D.


Biological availability of zinc from inorganic sources with excess dietary calcium.

The effects of chemical form of supplemental zinc and elevated dietary calcium on intestinal absorption of zinc were measured. Calves and rats were fed diets low in zinc, and zinc availability was the percentage increase of zinc in plasma with dietary supplementation of zinc. Availabilities of zinc supplied as zinc chloride, zinc sulfate, zinc oxide, and zinc carbonate were comparable in both calves and rats. Elevated amounts of dietary calcium as ground limestone reduced absorption of zinc in rats fed soy-protein but had no effect on absorption of zinc in the lactating cow. Thus, for cows consuming large amounts of calcium, an increase in the concentration of zinc beyond 40 ppm of the diet appears unnecessary.


Evaluation of automatic mastitis detection equipment.

An electronic sensor was evaluated as an instrument for early detection of mastitis. This method involved measuring the conductivity of milk continuously throughout the milking process and then establishing a conductivity ratio. The lowest conductivity measurement of the four quarters was a basis for assessing the degree of mastitis in the other quarters. This assumed that at least one of the quarters was normal at examination and the lowest reading was normal conductivity. The conductivity ratio was evaluated by comparison with the leukocyte concentration and combined leukocyte concentrations and cultural examiniations of milk samples from 1028 quarters. In healthy cows conductivities of milk from each of the quarters were similar. If, however, one or more quarters were infected, this milk showed higher conductivity compared to the noninfected quarter of the same cow. The conductivity ratio correctly identified 69% of the established cases of mastitis. For the Wisconsin Mastitis Test, 93.2% of the normal quarters were detected correctly by the conductivity ratio. Leukocyte counts were frequently high when there was no other evidence of mastitis. We believe the conductivity ratio is effective in detecting mastitis at an early stage of infection caused by most of the pathogenic microorganisms.


Genetic analysis of California mastitis test records. I. Coded tests.

A sample of 15,965 Holstein lactation records having California Mastitis Test scores for at least the first 9 mo of standard Dairy Herd Improvement production testing were studied for the effects of sire, parity, and year and month of calving. California Mastitis Test readings of "negative" or "trace" were coded normal while readings of "1", "2", or "3" were coded elevated. The frequency of elevated tests increased as parity increased. Effect of year of calving and a trend toward higher percentages of elevated coded test scores was significant. There was no distinct trend in elevated coded test score with month of calving. Sire effect on the incidence of elevation in the coded score was important. Heritability of first and second lactation monthly coded California Mastitis Test scores from a paternal half-sister analysis within herd, year, and season, for sires with at least 25 daughters ranged from .11 +/- .04 to .48 +/- .07. Genetic correlations between the third test and following tests of first and second lactations ranged from .25 +/-.15 to .58 +/- .18.


Genetic analysis of California mastitis test records. II. Score for resistance to elevated tests.

A lactation score for rating individual cows for their apparent resistance to elevation of California Mastitis test is described. The score uses the first nine monthly California Mastitis Tests weighted by the number and position of elevated coded tests. California mastitis test readings of negative and trace were coded "normal" and 1, 2, or 3 "elevated". A cumulative lactation score of 21 was assigned to lactations without elevation in coded test, and a score of zero was assigned to lactations with all nine tests elevated. The number and position of the elevated coded tests influenced the 305-day milk yield, and the position of elevated coded tests influenced lactation persistency. Differences were significant among sire progeny groups for the cumulative lactation score. Heritabilities for the cumulative lactation score were .48 +/- .07, .36 +/- .08, .46 +/- .15, and .23 +/- .12 for first, second, third, and fourth or later lactation groups. Selection for a high cumulative lactation score should reduce the occurrence of elevated coded test scores. The genetic correlation between 305-day milk yield and cumulative score was -.31 +/- .13 for first lactation records.


Photodegradation of riboflavin in milks exposed to fluorescent light.

Photodegradation of riboflavin in 50-ml samples of fluid milks exposed to fluorescent light (2690 lux) followed first-order reaction kinetics, and the reaction rate (s-1) averaged 1.86 x 10(-5) in skim milk and 1.47 x 10(-5) in whole milk. Additional evidence led us to conclude that photodegradation of riboflavin proceeds prior to the appearance of a light-induced off-flavor.


Blood and milk progesterone in pregnant and nonpregnant buffalo.

Changes in progesterone concentration of blood and milk were measured by radioimmunoassay in 10 Murrah buffalo up to 40 days after insemination. Progesterone concentration in blood plasma at estrus was .1 ng/ml which rose to a peak of 3.6 ng/ml on day 13. It continued to increase in animals that conceived but dropped to .6 ng/ml on 3 days before next estrus in those that failed to conceive. The average concentration of progesterone in milk was .5 ng/ml at estrus; it increased to 18 ng/ml on day 15, and thereafter it declined to 4.4 ng/ml 3 days preceding next estrus in nonpregnant animals. In pregnant animals, it was maintained and elevated further to 24.8 ng/ml on day 37. Progesterone in milk was four to five times higher than in blood plasma.


Variables associated with peripartum traits in dairy cows. IV. Seasonal relationships among temperature, photoperiod, and blood plasma prolactin.

Concentrations of prolactin in plasma were measured in 176 dairy cows and heifers from 13 days before calving to 2.5 days after calving over 21 mo. Prolactin averaged 35.1, 115.0, and 34.4 ng/ml prepartum (days -13 to -2), peripartum (days -1.0 to +.5), and postpartum (days +1.5 and +2.5). Season of the year affected prolactin in all periods. The linear covariate of daily photoperiod (hours of daylight per 24 h) accounted for as much variation in prolactin prepartum and postpartum as did linear covariates of both photoperiod and average daily temperature. However, it was possible to account for additional seasonal variation in prolactin peripartum by addition of the temperature covariate to the photoperiod covariate. Although photoperiod was related either directly or indirectly more than temperature to factors affecting prolactin seasonally, these statistical inferences cannot prove that prolactin is more dependent on photoperiod than on temperature because the two metereorological measures were correlated (r = .84). When the data were grouped for correlation analysis by months, correlations between temperature and prolactin among prepartum samples collected in the spring and in the fall were positive, small but significant.


Prostaglandin in milk, days open, and estrus detection in dairy cows treated with prostaglandin F2 alpha.

Prostaglandin F2 alpha was used to induce estrus in postpartum dairy cows to decrease calving interval and time spent on heat checks. The amount of prostaglandin residue in milk after treatment also was investigated. Twenty-two control cows, checked for heat twice daily, were bred at estrus after 55 days postpartum. Sixty-three cows checked on days 55 to 60 were either bred if in estrus or treated with 30 mg of prostaglandin F2 alpha injected intramuscularly on day 60 and bred at induced estrus or at 75 h posttreatment. Twelve cows were in heat between days 55 and 60 and were bred. Twenty-nine of 51 treated cows were seen in estrus; all of these were bred and 51.7% conceived at this time. Treated cows had fewer days to first service than did controls, but days open were not different, 105.7 versus 101.8. Fertility was similar. Controls required more heat checks than did treated cows (39 to 8.2). Milk from 17 cows at two milkings before and ten milkings after treatment had similar concentrations of prostaglandin (698 +/- 27 pg/ml) except for the first posttreatment milking when prostaglandin concentration almost doubled (1.293 +/- 143 pg/ml).


Measurement of estrogens in cow's milk, human milk, and dairy products.

Free natural estrogens in raw and commercial whole milk were quantitated by radioimmunoassay. The ranges of concentration of estrone, estradiol 17-beta, and estriol were 34 to 55, 4 to 14, and 9 to 31 pg/ml. Proportions of active estrogens (estrone and estradiol) in the fat phases of milk by radioactive tracer on separated milk were 80% and 65%. These findings were supported by radioimmunoassay of skim milk and butter. Equilibrium dialysis of skim milk with hydrogen 3 labeled estrogens showed that 84 to 85% of estrone and estradiol and 61 to 66% of estriol were protein bound. Whey proteins demonstrated a greater binding capacity than casein. This result was confirmed by radioimmunoassay of dry curd cottage cheese and whey. The concentrations in curd were 35, 11, and 6 pg/g. In whey they were 4, 2, and 3 pg/ml. The quantity of active estrogens in dairy products is too low to demonstrate biological activity. Butter was highest with concentrations of 539, 82, and 87 pg/g. Human colostrum demonstrated a maximum concentration of 4 to 5 ng/ml for estrone and estriol and about .5 ng/ml for estradiol. By the 5th day postpartum, they decreased to become similar to cow's milk.


A modified device for collecting milk from guinea pigs.

A modified device for milking small animals is discussed. The advantage of these modifications are 1) quiet operation, 2) ease of operation in animal room, and 3) quick change to allow the same device to be used on different animals. This device can be tailored to the test size as well as milk volume expected. Construction is simple, and materials are inexpensive.


A note on the representation of the performance of hemodialyzers.

The performance of hemodialyzers was expressed schematically using three dimensionless quantities. Compared with the usual representation in which the dialysance is plotted against the blood flow rate for each of the solutes of interest, this expression is considered to have the following advantages: (1) the function of a dialyzer to remove different solutes can be expressed by a single curve, (2) the effect of changing the membrane area, its permeability, and the flow rates on the performance can easily be understood, and (3) the effect of changing the blood flow rate on the ratio of the transport efficiency of two or more kinds of solutes can be evaluated. An estimate of the overall mass transfer coefficient is the only procedure necessary to move from the usual to the present expression. These analyses were applied to the performance of a commercial hemodialyzer, and it was verified that this representation could denote its operation fairly well.


A new semiautomated apparatus for hemofiltration.

A new semiautomated apparatus for hemofiltration has been described. It is a postdilutional hemofiltration system that utilizes the RP-610 dialyzer and is made of standard lines used for hemodialysis, a blood pump and two precise volumetric pumps, Logeais-TEC model, for the ultrafiltrate and for the substitution fluid. The ultrafiltrate compartment of the hemofilter is connected to a manometer for detecting positive or negative pressure. The transmembrane pressure TmP is given only by the pressure on the blood side that is regulated by the screw clamp in the venous line. Once started the whole system may be regulated by this screw clamp in order to maintain zero pressure in the ultrafiltrate compartment, provided that ultrafiltration rate does not exceed 65 ml/min. This system is sufficiently accurate to replace bed scales or any other gravimetric device.


Relative performance test of hollow fiber dialyzers.

While a number of different hollow fiber dialyzers are on the market today, the present author studied three of the cellulosic membrane dialyzers, SD-1, CF-1500 and K-102, as to their dialysance, solutes removal rate, UFR and blood residue characteristics. In order to compare these characteristics due to the difference of the membrane and the structural geometry of the dialyzers, the test results were analysed by means of analyses of variance.


A simple method for incorporating single pass dialysate delivery and controlled ultrafiltration with the RP-6 high flux dialyzer.

A simple hemodialysis protocol has been developed to permit significant "middle molecule" clearance, yet retain normal low molecular weight clearance. The high flux RP-6 dialyzer has been combined with a single pass dialysate delivery system to provide accurate control of ultrafiltration without resorting to specialized or expensive equipment. By operating the RP-6 in the co-current mode, a simple valve on the dialysate output can be used to regulate ultrafiltration. At QB = 200 ml/min and QD = 500 ml/min, CU = 127 ml/min and CB12 = 56 ml/min at zero ultrafiltration rate; these values increase considerably with ultrafiltration. This protocol offers dialysis centers with standard equipment the opportunity to use high flux membranes in a routine manner.


In vitro characterization of the RP-6 dialyzer: co-current and counter-current clearance as a function of ultrafiltration.

Analytical and graphical techniques are described for presenting clearance data as a function of ultrafiltration; thus for the first time comparison of clearance values between dialyzers can be made unambiguously. This simple method uses a hand calculator to determine three coefficients. Clearance has been shown to be accurately described by the equation C = alpha 1 + alpha 2 Qv + alpha 3 (1/QBi). This formula permits construction of easily read families of curves which can predict clearance values under most clinical situations. The RP-6 dialyzer is characterized by these methods for clearance of urea, glucose and vitamin B 12 for counter-current and co-current modes.


Osmotic ultrafiltration with dextran sodium sulfate potential for use in peritoneal dialysis.

Dextran sodium sulfate was evaluated in vitro as a potential non-absorbable osmotic agent for peritoneal dialysis. It was compared to poly(sodium acrylate) which has been shown previously to be effective in rats, but probably toxic. Dextran sodium sulfate induced osmotic ultrafiltration rates as high as 20 ml/min in water but only 2 ml/min in solution containing non-polymer electrolytes presumably because of Gibbs-Donnan effects. Compared to acrylate the dextran polymer has less sodium per gram, lower osmotic activity of polymer sodium, and yields less ultrafiltration at given transmembrane osmolalities. A non-toxic polymer more like acrylate would seem more promising as an osmotic agent for peritoneal dialysis.


In vivo measurement of blood recirculation during "Y" type single needle dialysis.

A method has been described and validated for obtaining a sample of blood, without separate venapuncture, which has the same urea and creatinine composition as systemic venous blood during hemodialysis. Using this technique, recirculation in vivo during "Y" type single needle dialysis, measured in 20 bovine fistulas, ranged from 6.9% to 56.5% and averaged 19.4% of blood flow rate as calculated from blood urea nitrogen; and averaged 22.0% with a range of 3.3% to 62.1% of blood flow rate as calculated from serum creatinine concentration. These results suggest that fistula puncture methods and devices that eliminate recirculation in the ex vivo blood circuit should be used to maximize dialysis efficiency.


Acoustical analysis of the auditory system of the cricket Teleogryllus commodus (Walker).

The basic auditory physiology of crickets, and particularly of Teleogryllus commodus (Walker) is examined and its behavior simulated by electrical analog networks, beginning from the simplest possible model and progressing by stages to the full system found in the real insect. It is found that the attenuation of sound in the auditory trachea plays a crucial role in the mechanism for directional hearing in even the simplest model and that the tracheal diameter is in fact appropriate to produce the desired attenuation. In a more complex model in which it is recognized that the auditory system probably responds to pressure changes in the tracheal sacs underlying the tympana rather than simply to tympanic motion, it is found that the phase shift produced by the combined effects of the central septum and the adjoining cavities leading to the spiracles is also important to hearing directionality. The final model which includes both tympana and spiracles is able to simulate both the hearing directionality and, in part, the frequency selectivity of the system. It appears, however, that a large measure of the observed frequency selectivity is due to some form of selectivity in the neural transducers themselves rather than in the simple acoustic components of the system.


Can intrinsic vowel Fo be explained by source/tract coupling?

There is extensive evidence that in the same phonetic environment the voice fundamental frequency (Fo) of vowels varies directly with vowel "height." This Fo difference between vowels could be caused by acoustic interaction between the first vowel formant and the vibrating vocal folds. Since higher vowels have lower first formants than low vowels the acoustic interaction should be greatest for high vowels whose first formant frequencies are closer in frequency to Fo. Ten speakers were used to see if acoustic interaction could cause the Fo differences. The consonant [m] was recorded in the utterances [umu] and [ama]. Although the formant structure of [m] in [umu] and [ama] should not differ significantly, the Fo of each [m] allophone was significantly different. However, the Fo of each [m] allophone did not differ significantly from the Fo of the following vowel. These results did not support acoustic interaction. However, it is quite reasonable to conclude that the Fo variation of [m] was caused by coarticulatory anticipation of the tongue and jaw for the following vowel. Another experiment is offered in order to help explain the physical causes of intrinsic vowel Fo. In this experiment Fo lowering was found at the beginning of vowels following Arabic pharyngeal approximants. This finding indicates that the Fo of pharyngeal constricting vowels, e.g., [ae] and [a], might be lowered as a result of similar articulary movements, viz. tongue compression and active pharyngeal constriction.


The perception of fundamental frequency declination.

A series of experiments was carried out to investigate how fundamental frequency declination is perceived by speakers of English. Using linear predictor coded speech, nonsense sentences were constructed in which fundamental frequency on the last stressed syllable had been systematically varied. Listeners were asked to judge which stressed syllable was higher in pitch. Their judgments were found to reflect normalization for expected declination; in general, when two stressed syllables sounded equal in pitch, the second was actually lower. The pattern of normalization reflected certain major features of production patterns: A greater correction for declination was made for wide pitch range stimuli than for narrow pitch range stimuli. The slope of expected declination was less for longer stimuli than for shorter ones. Lastly, amplitude was found to have a significant effect on judgments, suggesting that the amplitude downdrift which normally accompanies fundamental frequency declination may have an important role in the perception of phrasing.


Psychophysical tuning curves and auditory thresholds after hair cell damage in the chinchilla.

Chinchillas were treated with kanamycin sulfate (150--200 mg/kg/day) to produce high-frequency hearing loss extending to about 4.0 kHz. Thresholds and psychophysical tuning curves (PTCs) were obtained before and after treatment, utilizing a shuttlebox avoidance procedure, and cochlear hair cells were evaluated under phase contrast microscopy. Hair cell loss resulting from kanamycin treatment varied from restricted lesions of the outer hair cells (OHCs) in the cochlear base, with no loss of inner hair cells (IHCs), to more extensive lesions involving both OHCs and IHCs. Threshold shift of at least 40 dB was always associated with OHC loss. PTCs obtained from frequency regions exhibiting 40--50 dB of threshold shift were normal in shape. With threshold shift in excess of 50 dB, PTCs were progressively distorted, with truncation of the tip segment and in some cases increased sensitivity of the tail segment. The results suggest that the threshold of optimally functional IHCs after kanamycin-induced OHC loss is about 40 dB higher than normal. Threshold shift in excess of 40 dB may represent IHC damage. IHCs are capable of transducing the fine-frequency information necessary for generating normally sharp PTCs in the absence of OHCs. However, with threshold shift in excess of approximately 50 dB, this frequency resolution is increasingly compromised.


Unmasking produced by combination tones.

This experiment investigated some interactions between combination tones (CT) and unmasking. Data were obtained from nine normal-hearing listeners in a forward-masking paradigm in which a 2000-Hz, 35-dB SPL masker preceded a 2000-Hz test signal. An adaptive, three-interval forced-choice procedure was employed to estimate the threshold for the test signal. This measurement provided a baseline. When a second sinusoid, the suppressor, of variable frequency and 55 dB SPL was presented concurrently with the masker, the amount of masking could be less than in the baseline condition. This two-tone unmasking was observed when the suppressor was approximately 2300 Hz. In the cubic difference tone (CDT) condition, two higher-frequency sinusoids of 80 dB SPL (with the lower frequency fixed at 2800 Hz) were added to the masker. In the difference tone (DT) condition, two higher-frequency sinusoids of 100 dB SPL (with the lower frequency fixed at 3500 Hz) were added to the masker. None of these sinusoids produced unmasking when presented individually, but when the CDT and DT were approximately 2300 Hz, unmasking was observed. The unmasking produced by the CTs was similar in its frequency characteristics to that of the single, suppressor tone. These results indicate that unmasking can be produced by CTs, just as if CTs were present in the stimulus. These data indirectly support the notion that CTs may be present in the form of traveling waves propagated along the basilar membrane.


Location of structurally similar areas in chinchilla cochleas of different lengths.

In chinchillas, the length of the organ of Corti was found to vary by as much as 26% of the mean (18.31 mm). In specimens of different lengths, areas in which the basilar membrane and organ of Corti have the same physical dimensions were found to be located at the same percentage distance along the cochlear partition. Average densities of the inner and outer hair cells were noted to decrease with increasing cochlear length. However, the rate of decrease in density was less than the rate of increase in length. These findings indicate that long cochleas have a greater amount of the organ of Corti (and hence more sensory cells) in a given frequency region.


The spectral content of the cochlear microphonic measured in scala media of the guinea pig cochlea.

Cochlear microphonic (CM) in response to low-frequency tonal stimuli, measured as a function of sound-pressure level (SPL) in scala media of the guinea pig cochlea, was averaged and Fourier analyzed. The slope of the amplitude of the Nth CM harmonic versus sound intensity in log-log coordinates was approximately N (1 less than or equal to N less than or equal to 5) in the first three cochlear turns, but notable variations on such a slope rule were found to apply to CM in turn I. CM harmonic phases plotted versus SPL were found to group into two distinctive categories expressly delimited by whether the order of the harmonic was even or odd. Some difference between CM recorded between scala media and scala tympani and recorded between scala media and the animal's neck could be attributed to neural contamination. We also found CM in its saturation region to have a hysteretic relation to the input sound pressure. At high sound levels, large, physiologically produced acoustic harmonics existed at the animal's eardrum. Our data support an asymmetrical, saturating, single-valued nonlinearity as a model for CM generation at low sound levels. At higher sound levels a different, more complex, hysteretic nonlinearity seems mandatory.


Comparison of the spectra of the cochlear microphonic and of the sound-elicited electrical impedance changes measured in scala media of the guinea pig.

The harmonic structure of the cochlear microphonic (CM) and that of a sound-elicited signal which we have considered as an (apparent) changing resistance (CR) were simultaneously determined in scala media of the first turn of the guinea pig cochlea. We analyzed our data in the context of the Davis variable resistance hair-cell model (1965), which predicts CM and CR to be proportional to each other. But, plotted as functions of the sound-pressure level, CM and CR were found to have qualitatively similar but quantitatively disproportionate spectra. The preparations with the highest endolymphatic potential showed the least correspondence between the spectra of the two measured quantities. The phase angles of the fundamental components in CM and CR were equal within approximately 10 degrees, but the phase of the even harmonics of the two independent measures commonly differed by approximately 180 degrees at lower SPLs. Although most data were collected using 160-Hz tonal stimulation, tones with frequencies up to 1280 Hz produced qualitatively similar results. The CM and the CR both varied slightly with the level of the alternating current used to probe the CR. Considered on a quantitative basis, consistent with the accuracy of our measurements, any model which reduces to a fixed source, a fixed resistance, and a single linear, time-varying resistance cannot mimic the most significant, commonly found aspects of our CM and CR data. An alternate model incorporating a nonlinear, time-invariant resistance is able to account for some of the data. The output of the model is correctly considered a (time) changing resistance, or apparent changing resistance; but the model demonstrates that similar experimental results are not necessarily evidence for a time-varying resistor as originally proposed by Davis.


BSR (wave V) and N1 latencies in response to acoustic stimuli with different bandwidths.

Shortlatency averaged responses to 0.02--6 kHz broadband (BB) and 2 kHz narrow-band (NB) filtered clicks were recorded from the ear canal and the vertex of five adults with normal audiograms. Response latencies to the signals presented in quiet and with masking noise were compared. For constant spectrum level, the low-frequency limit of the masking noise was systematically increased to 6 kHz. The upperfrequency limit was always 8 kHz. For signals at 40 dB HL, the latencies of wave V and N1 decreased as the lower limit of the noise was raised and nearly equaled the latency for the signals presented in quiet. For signals at 70 dB HL, the latency in quiet was much less than that observed for all noise conditions, i.e., frequencies above 8 kHz would be required to interfere with the signal-dependent synchronous neural activity. Similar effects were measured for both wave V and N1, but the analysis of wave V and N1, but the analysis of wave V--N1 latency intervals suggested a possible signal dependency.


Loss of auditory sensitivity following exposure to spectrally narrow impulses.

Damage-risk criteria (DRC) for impulse noise do not presently take the spectrum of an impulse into direct account; yet it is clear that the ear is spectrally tuned. In order to establish the sensitivity of various sections of the cochlear duct to trauma from impulses, ears were exposed to 100 spectrally narrow impulses (1.0, 5.0, or 10.0 kHz) delivered in 10 min. Changes in auditory sensitivity were measured by an electrocochleographic technique in 43 cat ears and a threshold of loss established for each type of impulse. Expressed in SPL at the ear drum, the loss threshold rose at 3.2 dB/octave between 1.0 and 10.0 kHz. Expressed in stapes displacements, the loss threshold fell at 5.4 dB/octave in the same region. This curve was used to establish a tentative shape for a DRC for the human ear for impulse noise. The patterns of loss, rates of loss, lack of recovery, and loss thresholds are discussed with respect to their probable physiological basis with conclusion that mechanical displacement rather than metabolic exhaustion is the most reasonable causative factor.


Aberrant tonotopic organization in the inner ear damaged by kanamycin.

Spiral ganglion cell recordings were obtained from normal and kanamycin-damaged guinea pig cochleas. Results show that kanamycin poisoning, which causes loss of outer hair cells, leads to a loss of sharp, sensitive tuning and, in addition, a shift to lower frequencies in the tuning curves from a damaged region. The normal tonoptic pattern of organization is therefore greatly disrupted in the damaged cochleas.


Encoding of steady-state vowels in the auditory nerve: representation in terms of discharge rate.

Responses of large populations of auditory-nerve fibers to synthesized steady-state vowels were recorded in anesthetized cats. Driven discharge rate to vowels, normalized by dividing by saturation rate (estimated from the driven rate to CF tones 50 dB above threshold), was plotted versus fiber CF for a number of vowel levels. For the vowels /I/ and /e/, such rate profiles showed a peak in the region of the first formant and another in the region of the second and third formants, for sound levels below about 70 dB SPL. For /a/ at levels below about 40 dB SPL there are peaks in the region of the first and second formants. At higher levels these peaks disappear for all the vowels because of a combination of rate saturation and two-tone suppression. This must be qualified by saying that rate profiles plotted separately for units with spontaneous rates less than one spike per second may retain peaks at higher levels. Rate versus level functions for units with CFs above the first formant can saturate at rates less than the saturation rate to CF to-es or they can be nonmonotonic; these effects are most likely produced by the same mechanism as that involved in two-tone suppression.


Postpartum survival of mice exposed in utero to ultrasound.

We found no credible enhancement of neonatal mortality in mice exposed in utero on Day 8 of gestation to ultrasound at 0.44 W/cm2 (+/- 20%) spatial average intensity, 2 MHz, continuous wave, for 60--180 s in a 37 degrees C water bath. This result is compared with the adverse effect on neonatal survival reported by Curto [in Ultrasound in Medicine (Plenum, New York, 1976), Vol. 2, pp. 535--536] for exposure on Day 14 of gestation at about 0.125 to 0.5 W/cm2, 1MHz, continuous wave, for 180 s in a 30 degrees C bath. It is concluded that a temporary reduction in fetal viability, lasting from 4 days to less than 10 days after exposure, could account for both sets of data. It is also evident from these data that improved methods of determining intensities within mammalian tissues are highly desirable.


Comments on the effects of overstimulation on microphonic sensitivity.

Utilizing the differential recording technique, microphonic isopotential measurements were carried out before and after overstimulation. Recordings were made in the first and third turns of guinea pig cochleas. The exposure stimuli were pure tones of frequencies near the best frequency of the recording site. The results were suggestive of differences in the effects of overstimulation in different turns of the cochlea, at least as they are manifested electrophysiologically.


Acoustic invariance in speech production: evidence from measurements of the spectral characteristics of stop consonants.

On the basis of theoretical considerations and the results of experiments with synthetic consonant-vowel syllables, it has been hypothesized that the short-time spectrum sampled at the onset of a stop consonant should exhibit gross properties that uniquely specify the consonantal place of articulation independent of the following vowel. The aim of this paper is to test this hypothesis by measuring the spectrum sampled at the onsets and offsets of a large number of consonant-vowel (CV) and vowel-consonant (VC) syllables containing both voiced and voiceless stops produced by several speakers. Templates were devised in an attempt to capture three classes of spectral shapes: diffuse-rising, diffuse-falling, and compact, corresponding to alveolar, labial, and velar consonants, respectively. Spectra were derived from the utterances by sampling at the consonantal release of CV syllables and at the implosion and burst release of VC syllables, and these spectra (smoothed by a linear prediction algorithm) were matched against the templates. It was found that about 85% of the spectra at initial consonant release and at final burst release were correctly classified by the templates, although there was some variability across vowel contexts. The spectra sampled at the implosion were not consistently classified. A preliminary examination of spectra sampled at the release of nasal consonants in CV syllables showed a somewhat lower accuracy of classification by the same templates. Overall, the results support an hypothesis that, in natural speech, the acoustic characteristics of stop consonants, specified in terms of the gross spectral shape sampled at the discontinuity in the acoustic signal, show invariant properties independent of the adjacent vowel or of the voicing characteristics of the consonant. The implication is that the auditory system is endowed with detectors that are sensitive to these kinds of gross spectral shapes, and that the existence of these detectors helps the infant to organize the sounds of speech into their natural classes.


Bimodal cues for speech loudness.

This paper presents a bimodal (audio-visual) study of speech loudness. The same acoustic stimuli (three sustained vowels of the articulatory qualities "effort" and "noneffort") are first presented in isolation, and then simultaneously together with an appropriate optical stimulus (the speaker's face on a video screen, synchronously producing the vowels). By the method of paired comparisons (law of comparative judgment) subjective loudness differences could be represented by different intervals between scale values. By this method previous results of effort-dependent speech loudness could be verified. In the bimodal study the optical cues have a measurable effect, but the acoustic cues are still dominant. Visual cues act most effectively if they are presented naturally, i.e., if acoustic and optical effort cues vary in the same direction. The experiments provide some evidence that speech loudness can be influenced by other than acoustic variables.


Effects of selected vocal disguises upon speaker identification by listening.

This research was designed to investigate the effects of selected vocal disguises upon speaker identification by listening. The experiment consisted of 360 pair discriminations presented in a fixed-sequence mode. The listeners were asked to decide whether two sentences were uttered by the same or different speakers and to rate their degree of confidence in each decision. The speakers produced two sentence sets utilizing their normal speaking mode and five selected disguises. One member of each stimulus pair in the listening task was always an undisguised speech sample; the other member was either disguised or undisguised. Two listener groups were trained for the task: a naive group of 24 undergraduate students, and a sophisticated group of three doctoral students and three professors of Speech and Hearing Sciences. Both groups of listeners were able to discriminate speakers with a moderately high degree of accuracy (92% correct) when both members of the stimulus pair were undisguised. The inclusion of a disguised speech sample in the stimulus pair significantly interfered with listener performance (59%--81% correct depending upon the particular disguise). These results present a similar pattern to this authors' previous results utilizing spectrographic speaker-identification tasks (Reich et al., 1976).


Intensity discrimination with gated and continuous sinusoids.

Detectability of sinusoidal signals at several durations was measured in the presence of sinusoidal maskers of the same frequency. Maskers were either continuous or gated on and off with the signal. For all signal durations and both types of maskers, delta I/I varied with I raised to the -0.1 power, approximately. Psychometric functions were two or three times steeper with continuous than with gated maskers. Signal duration had only a small effect that varied with the masking condition.


Perception of the simple difference tone (f2-f1).

The present study examined the dependence of difference tone level [L(f2-f1)] on the following parameters of the two-tone input: f1, f2/f1 (f2 greater than f1), L1, L2, and L1 = L2. Difference tone levels were estimated in four normal hearers using a 2AFC adaptive temporal gap-masking paradigm. The key finding in this study is the apparent interaction of each factor with the other. For example, primary level (L1 = L2) was found to affect the dependence of L(f2-f1) on f1 and on f2/f1. In addition, the frequency separation of the primaries (f2/f1) was also seen to exert an influence on the dependence of difference tone level on L1, L2, and L1 = L2.


Relationship between psychophysical tuning curves and "suppression".

This study examined two-tone unmasking and auditory frequency selectivity about 3 kHz for the purpose of demonstrating a qualitative relationship between the two. An adaptive 2IFC forward-masking procedure was used to collect psychophysical tuning curves (PTC's) and two-tone masking data under a quiet and noise condition for the same normal-hearing listeners. In the noise condition, a narrowband noise masker, centered one decade down from the probe, was gated on with the tonal masker(s). Kiang and Moxon [J. Acoust. Soc. Am. 55, 620-630 (1974)] have found that low-frequency narrowband noise serves to decrease the sharpness of electrophysiological tuning curves by affecting only the tip segments. The data for four highly practiced listeners indicate that the gated-noise masker was effective in broadening the PTC's and in lessening the magnitude of two-tone unmasking. The mutually reflected changes in tuning curves and in two-tone unmasking indicate a close relationship between frequency selectivity and unmasking: the greater the magnitude of unmasking above the center frequency of the PTC, the sharper the tuning of the PTC.


Is pitch a learned attribute of sounds? Two points in support of Terhardt's pitch theory.

Terhardt [J. Acoust. Soc. Am. 55, 1061-1069 (1974)] postulated a pitch perception model wherein a learning stage constitutes an integral part: it is only repeated exposure to patterns of spectral pitch that will generate the percept of virtual pitch (i.e., the residue). Two examples, one clinical and one musical, are cited to support the idea that perception of the pitch of complex tones represents a case of pattern perception which is acquired with experience.


Acoustic correlates of perceived sexual identity in preadolescent children's voices.

This project was undertaken to provide information about the sexual characteristics of preadolescent children's voices. In one series of experiments, perceptual judgments of sexual identity were obtained in response to 73 children's productions of isolated whispered and normally phonated vowels, normally spoken sentences, and sentences spoken in a monotonous fashion (Bennett and Weinberg, 1978). The purpose of this portion of the project was to describe certain acoustic and temporal characteristics of these children's speech samples, and to assess the relationship of these variables to perceptual judgments of sexual identity. Sexual differences in the frequency location of vocal tract resonances were significantly correlated with listener judgments of child sex in all four utterance conditions. The origin of the observed differences in vocal tract resonance characteristics is discussed with reference to possible sexual differences in vocal tract size as well as certain articulatory behaviors. Average fundamental frequency was significantly related to listeners' sex identifications in two utterance conditions. However, the influence of this variable was considerably less pronounced when compared to vocal tract information. Although certain measures of fundamental frequency variability (mean duration of level inflections and the rate of frequency change associated with upward shifts) were significantly related to perceptual measures of sexual identity, these cues were also interpreted to play a secondary role in defining maleness and femaleness in these children's voices.


Measurements of responsiveness in bronchoprovocation testing.

The relative sensitivity and usefulness of FEV1 and SGaw measurements in determining airway responsiveness to stimuli causing changes in bronchomotor tone depend to a great extent on the population studied. Though neither test provides a great deal of information regarding the site of airway obstruction, when used together they provide a reliable and sensitive indicator of airway responsiveness.


Relationship between airways response to allergens and nonspecific bronchial reactivity.

Bronchial inhalation challenges to histamine, methacholine, and at least one antigen were performed on 183 asthmatic patients who previously had received skin tests to at least 16 different antigens. Individuals with a positive skin test and a positive antigen inhalation challenge to the same antigen had lower thresholds of response to both histamine and methacholine. This pattern was statistically significant for mixed trees, mixed grasses, mixed molds, and house dust but not for mixed ragweed. For those individuals who had a negative antigen inhalation challenge, skin test reactivity (positive or negative) alone was not associated with a different threshold of response to histamine or methacholine. Also, a higher percentage of positive antigen inhalation challenges were seen in the group of individuals with a low threshold of response to both histamine and methacholine than in groups with either a moderate or high threshold of response to these chemical agents. The results imply that at least two factors are associated with a positive bronchial inhalation challenge to a specific antigen: nonspecific airways hyperreactivity, as indexed by a methacholine or histamine inhalation challenge, and a positive skin test.


Aspirin and concomitant idiosyncrasies in adult asthmatic patients.

The nasal and respiratory symptoms observed after oral challenge to aspirin (ASA), tartrazine, and other nonsteroidal anti-inflammatory substances are best described as idiosyncratic reactions. A positive response to oral challenge, defined as a 20% fall in forced expiratory volume in 1 sec (FEV1) from baseline for up to 4 hr, occurred in 44 of 230 patients with ASA, 11 of 277 with tartrazine, 2 of 93 with sodium salicylate, and 2 of 69 with acetaminophen. No one had a positive response to tartrazine, sodium salicylate, or acetaminophen who was not also positive to ASA. The dose of ASA causing a positive response was less than 5 grains in 95% of the patients. Of 50 patients with a suspicious history studied in detail, 96% of those with ASA idiosyncrasy had sinusitis and 71% had nasal polyps. Methacholine challenges and random circulating and sputum eosinophils did not differentiate patients with a negative challenge from those with a positive challenge. However, patients with a positive history and positive challenge had significantly more random nasal eosinophils than those with negative aspirin challenges. The term "aspirin triad" has outlived its usefulness since ASA idiosyncrasy can exist in patients lacking certain components of the triad. ASA idiosyncrasy is unsuspected in many patients and possibly overdiagnosed in others.


Selective immunoglobulin A deficiency associated with modular lymphoid hyperplasia.

Nodular lymphoid hyperplasia (NLH) has been firmly associated with syndromes of hypogammaglobulinemia but not with selective absence of IgA. We report the case of a 5-yr-old girl with the triad of selective IgA deficiency, NLH of the small bowel, and giardiasis. Results of an extensive immunologic investigation, including immunohistochemical examinations of small bowel biopsies, support the hypothesis that the basic defect responsible for IgA deficiency in this patient was the failure of precursor IgM-bearing lymphocytes to differentiate into IgA-producing plasma cells. Furthermore, the abundance of IgM-bearing cells in biopsy specimens demonstrates the existence of a compensatory mechanism in the intestine to substitute IgM for the absent IgA.


Effect of thymosin on lymphoid cells from human fetal organs.

Human fetal lymphoid cells from the thymus, blood, spleen, liver, and kidney of twelve 6-to-24-wk-old fetuses were studied for their ability to respond to thymosin by the alteration of E-rosette forming cells (E-RFC) and EAC-rosette forming cells (EAC-RFC). The preincubation of spleen cells with 100 micrograms thymosin-V1 effected a statistically significant increase in E-RFC, while no changes were observed in the lymphoid cells from blood or other organs. EAC-RFC assay revealed some increases in blood, thymus, and spleen; however, they were not statistically significant. Our results suggest that the fetal spleen may play an important role in the development of primitive immunocytes into mature cells and that this development is affected by thymic hormone.


The anatomy of a dietetic counseling interview.

Dietetic students in a course on interviewing skills were given an opportunity to practice interviewing, first with "coached," volunteer clients, then with real clients. Their interviews were taped and later analyzed as to content and approach. In trying to develop rapport during the "relationship-establishing" phase of the interview, the students asked questions which required mininal self-exploration by the client to answer (closed questions), five times as often as any other type of question. For effective counseling which results in changed behavior by clients, skills in counseling which develop an understanding of clients' feelings must be learned and implemented in counseling settings.


Some determinants of work performance in foodservice systems. Job satisfaction and work values of school foodservice personnel.

Job performance, job satisfaction, and work orientation of 304 women foodservice employees in twenty-four schools in seven districts were examined. Work values and job satisfaction of school and hospital foodservice employees were also compared. Work values varied little between the two groups. The school employees, however, were more satisfied with their work, supervision, and co-workers than were the hospital employees. School employees were divided into high- and low-performance groups through supervisory ratings of six dimensions of performance. The high-performance group had significantly higher satisfaction scores than the low-performance group. The former group had been employed longer and worked more hours per day than the latter.


Nutrient intake of low-income, black families in southwestern Mississippi.

A dietary intake study for 250 low-income households in Claiborne County in southwestern Mississippi was conducted from June through August 1974. Data were obtained during daily home visits for seven days by trained college students. The adequacy of nutrient intake for individuals was evaluated by comparing the data with the 1974 Recommended Dietary Allowances by age and sex. The data was also compared with those of the Ten-State Nutrition Survey and HANES. Mean intakes of protein, vitamin A, thiamin, riboflavin, and ascorbic acid for all subjects were above the RDAS; those of energy, calcium, iron, and preformed niacin were below the allowances. Whereas calcium was the nutrient least adequately consumed by all persons, protein was most adequately consumed. Sixty per cent of children had calcium intakes below two-thirds of the allowance. By sex, 66.7 per cent of all males and 73.3 per cent of all females had calcium intakes below two-thirds of the standard. None of children received less than two-thirds of the allowance for protein. Nutrient intake was low for a substantial number of the subjects. Adolescents, ages eleven to eighteen years, of both sexes had the poorest diets for all nutrients. Regarding the sex difference, females had better nutrient intakes than did males for all nutrients except calcium and iron.


Nutritive intake of black and Hispanic mothers in a Brooklyn ghetto.

The nutritional status of black and Hispanic mothers living in the Bedford-Stuyvesant section of Brooklyn, New York, was evaluated, using three-day dietary recall, a questionnaire on food buying and preparation techniques, and anthropometric measurements. Mean nutrient intake of both groups was considerably lower than the 1974 Recommended Dietary Allowances for all nutrients studied except protein, ascorbic acid, and phosphorus. Body weight and triceps skinfold values for both groups were higher than standard, suggesting obesity. Reasons for these findings are discussed with emphasis on the importance of nutrition education.


Microteaching: a model for employee counseling education.

An instructional model for the implementation and use of videotape simulation to improve dietetic students' skills in employee counseling was explored in the coordinated undergraduate program at the University of Tennessee, Knoxville. A five-day intensive workshop was conducted for senior students in the program, utilizing the microteaching technique. Students and actors simulated an employee counseling session on videotape; then, a small group and a clinical instructor evaluated the session. Suggestions from these evaluations were used in a repeat of the situation on videotape. A team of experts randomly viewed all the situations, judging a significant improvement in composite scores for the workshop participants. The students indicated on a Self-Perception of Confidence (SPOC) scale that they felt a higher degree of comfort in handling potential employee counseling after completing the workshop. They were pleased with the workshop and suggested expansion of the technique to other phases of their dietetic education.


The dietetic student's introduction to the medical record.

With the goal of introducing the dietetic student to the medical record and her role as a professional in the use of this document, a series of self-instruction modules was developed, evaluated, and revised. Field testing indicated that students attained a significant gain in knowledge after exposure to the modules. Further, students' comments indicated that the self-instructional approach was well received and quite helpful.


Prevention of psychiatric recidivism: a model service.

This article describes the patient-care activities of a medical school multidisciplinary section on geriatric psychiatry. The main treatment goal is the prevention of psychiatric recidivism. An index of this prevention is the re-admission rate, since the risks of institutionalization and recidivism tend to rise with each successive admission. The Section reported a re-admission rate of 4 percent for the first year of operation, a rate significantly less than that reported in the literature. The Section's achievement is predicated upon compliance with the requirements for optimal mental health care of the elderly. The protocol is presented in the hope that it may help others who wish to start such a service.


Erythrocyte parameters in the elderly: an argument against new geriatric normal values.

Erythrocyte parameters in 292 unselected geriatric patients were studied retrospectively. Statistically significant mean decreases compared to the laboratories' normal mean values were found in the red blood cell count (RBC), hemoglobin level, hematocrit, and mean corpuscular hemoglobin concentration; there also was a slight increase in mean corpuscular volume and mean corpuscular hemoglobin. However, when 17 patients with a hemoglobin level less than 10 gm/dl or a hematocrit reading less than 35 percent were excluded, all of the mean values for erythrocyte parameters fell within the normal range. In 71 percent of these 17 patients the etiology of the anemia was documented. Although one cannot definitely exclude a slight change in erythrocyte parameters with aging, it is concluded that the establishment of so-called new geriatric norms is premature, as the population studied included patients with various diseases. Good medical practice dictates continued evaluation and monitoring of patients in whom erythrocyte values are outside the established normal ranges.