Mechanism of action of colchicine in acute urate crystal-induced arthritis.

Phagocytosis of urate crystals by human or rabbit neutrophils induces the synthesis and release of a glycoprotein, the crystal-induced chemotactic factor (CCF), which is chemotactically active both in vitro and in vivo. It has been proposed that CCF is a prime mediator of the acute gouty attack. Colchicine has been shown to decrease the production and release of this factor in vitro. In these studies, colchicine, at nonleukopenic doses, is shown to abrogate the acute arthritis induced by monosodium urate crystals in rabbits, but to have no effect upon the arthritis induced by the injection of the purified cell-derived chemotactic factor. Serum colchicine levels were 0.48-0.58 muM at 30 min and 0.12-0.3 muM at 90 min after intravenous injection of 0.2 mg/kg colchicine. Peripheral blood polymorphonuclear leukocytes obtained from colchicine-treated animals migrated normally towards a chemotactic stimulus but failed to produce CCF after phagocytosis of monosodium urate crystals. The dialyzed synovial fluid from rabbits injected with microcrystalline sodium urate contained chemotactic activity that was not present when animals were also given intravenous colchicine or injected intra-articularly with the chemotactic factor formyl-methionyl-leucyl-phenylalanine. Furthermore, the synovial fluid from rabbits injected with microcrystalline sodium urate significantly decreased (125)I-CCF binding to neutrophils. The binding of (125)I-CCF to its neutrophil receptor was not significantly reduced by the synovial fluid of colchicine-treated rabbits nor by the synovial fluid of control rabbits injected with the chemotactic factor formyl-methionyl-leucyl-phenylalanine. Colchicine (10 and 0.1 muM) was shown to have no effect upon the binding of (125)I-CCF to its cell receptor.


Radioimmunochemical quantitation of human adenosine deaminase.

Markedly reduced or absent adenosine deaminase activity in man is associated with an autosomal recesive form of severe conbined immunodeficiency disease. To further define the genetic nature of this enzyme defect, we have quantitated immunologically active adenosine deaminase (CRM) in the hemolysate of homozygous deficient patients and their heterozygous parents. A highly specific radioimmunoassay was developed capable of detecting 0.05% of normal erythrocyte adenosine deaminase. Hemolysates from nine heterozygotes (five families) showed a wide range in CRM (32--100% of normal) and variable absolute specific activities with several being at least 1 SD BELOW THE NORMAL MEAN. Hemolysates from four unrelated patients showed less than 0.09% adenosine deaminase activity with CRM ranging from less than 0.06 to 5.6% of the normal mean. In conclusion, heterozygote and homozygote hemolysates from five of the eight families analyzed revealed variable levels of CRM suggesting heterogeneous genetic alteration or expression of the silent or defective allele(s) of adenosine deaminase.


Excretion and metabolism of catecholamines by the isolated perfused rat kidney.

The excretion and metabolism of labeled epinephrine and norepinephrine by the isolated, perfused rat kidney were studied. The excretion of both catecholamines significantly exceeded the amount filtered, thus providing direct evidence of net tubular secretion. Renal clearance of epinephrine was significantly greater than that of norepinephrine. Tubular secretion was a linear function of the concentration of unbound catecholamine in the medium with no demonstrable tubular maximum at the concentrations studied. The isolated kidney removed catecholamines from the medium by metabolism as well as excretion in the urine. O-Methylation was the major metabolic route and O-methylated metabolites were rapidly excreted and concentrated in urine. Preferential excretion and metabolism of epinephrine were confirmed in double-label experiments in which [14C]epinephrine and [3H]norepinephrine were perfused together. The ratio of 14C:3H in urine exceeded that in perfusion medium for total radioactivity as well as for catecholamines and O-methylated amines. The present study thus provides direct evidence for (a) net tubular secretion of epinephrine and norepinephrine with a direct relationship between secretion and medium concentration; (b) significant renal metabolism of both epinephrine and norepinephrine with O-methylation as the major metabolic route; and (c) preferential excretion and metabolism of epinephrine.


Genetic control of the eighth component of complement.

Using isoelectric focusing in polyacrylamide gel and a hemolytic assay for development of patterns, extensive, structural polymorphism in human C8 has been delineated. Two alleles, C8A and C8B, have been identified in orientals, with gene frequencies of 0.655 and 0.345. In blacks, what appears to be a third common allele was found, so that frequencies were 0.692, 0.259, and 0.049 for C8A, C8B, and C8A1. In whites, C8A1 was rare with a frequency of 0.003, and frequencies for C8A and C8B were 0.649 and 0.349. Inheritance was autosomal codominant in family studies and the distribution of types in random unrelated populations fit the Hardy-Weinberg equilibrium in all groups. C8 allotypes have been determined for two previously studied families, each with a homozygous C8-deficient propositus. This study suggests that C8 deficiency is a silent or null allele of the C8 structural locus, and that half normal levels of C8 cannot be used as a single criterion for the establishment of heterozygous C8 deficiency. C8 allotypes, as well as 18 other autosomal markers, were also determined for 24 families. The C8 structural locus is not closely linked to these markers, including the human histocompatibility loci complex.


Deletion of the A gamma-globin gene in G gamma-delta beta-thalassemia.

In an individual homozygous for G gamma-delta beta-thalassemia, a physical alteration in gamma-globin gene organization was detected by restriction enzyme mapping. The data indicated that the absence of A gamma-globin chains resulted from extension of the DNA deletion from the delta beta-globin gene region into the gamma-globin gene region rather than a functional disturbance of gamma-gene expression.


Platelet function in beta-thalassaemia major.

Abnormal platelet aggregation was found in eight (44%) of 18 patients with beta-thalassaemia major and transfusional iron overload. The aggregation defect bore no correlation with the degree of hepatic fibrosis, liver function tests, whether or not splenectomy had been performed, the degree of iron overload, haematocrit, platelet count, serum vitamin E level, or leucocyte ascorbate concentration. Only three of the 18 patients showed prolonged bleeding times as well as abnormal platelet aggregation, and only one of these suffered clinically significant haemorrhage. The results show that a proportion of patients with beta-thalassaemia major have abnormal platelet function. It is possible, however, that the in vitro abnormality might be due partly to artefacts induced by manipulations required to remove the abnormal thalassaemic red cells, and this may explain the much lower incidence of significant haemorrhage.


Platelet aggregation studies during transient hypoglycaemia: a potential method for evaluating platelet function.

The effect of acute hypoglycaemia on platelet function was examined in patients undergoing an insulin stress test. Enhanced platelet aggregation was observed in all cases but platelet count, platelet adenine nucleotides, and the plasma level of von Willebrand factor were unchanged overall. The onset of the hypoglycaemia-induced increase in platelet aggregation coincided with the lowest blood glucose levels recorded and with the clinical signs of adrenaline release. Increased platelet aggregation was maintained thereafter for the two-hour test period. There was no apparent correlation with changes in cortisol, growth hormone, and prolactin. No change in platelet function was observed after the administration of L-dopa. We suggest that the measurement of platelet aggregation during a standard insulin stress test may provide a means of evaluating platelet function in vivo and the influence of drugs thereon.


Effect of dextran sulphates on thrombin activity.

To clarify the action of dextran sulphate, a heparin analogue, in the clotting of fibrinogen by thrombin, determinations were carried out on the clotting activity, the release of fibrinopeptides from fibrinogen, and the hydrolytic activity of thrombin against a peptide chromogenic substrate in the absence or presence of antithrombin III (heparin cofactor). It was shown that dextran sulphate itself inhibited thrombin activity, and its inhibition was dependent on the molecular weight and the sulphur content of the dextran sulphate. Although heparin markedly enhanced the antithrombin activity of antithrombin III, dextran sulphate did not activate antithrombin III.


Increased interaction of vascular endothelium and leucocytes after administration of antiplatelet serum: role in the developing vascular defect.

Antiplatelet serum (APS) induced an increase in the stickiness of white cells which manifests itself in the increase in number of granulocytes rolling along or sticking to the venous endothelium. Lidocaine treatment prevented the increased stickiness of white cells and, at the same time, the microvascular haemorrhage developing after APS. It can be assumed that increased stickiness of white cells after APS may contribute to endothelial damage.


Cytokinetic studies of crypts in convoluted human small-intestinal mucosa.

Forty-seven peroral biopsy specimens of duodenojejunal mucosa showing convolutions were obtained from patients with a variety of clinical disorders. These mucosal samples were divided into three groups according to the extent of the convolutions and the severity of the accompanying histopathological changes; the cytokinetic status of the crypts in the three groups was then analysed and compared. Those in which the mucosae were predominantly or totally convoluted (group 3) showed the most notable cytokinetic changes: crypts were hyperplastic and crypt cell production rate was markedly increased compared with the other two groups and with morphologically normal control mucosae. In the case of one patient with mucosal changes of group 3 severity, additional studies were carried out using vincristine to produce metaphase arrest. The cell cycle time of 27 hours was greatly shortened compared with a control value of 45 hours.We find that the presence of convolutions in small-intestinal mucosal biopsy specimens is accompanied by an increase in the rate of cell production from the crypts, which is presumably related directly or indirectly to the rate of loss of mature enterocytes from the surface of the mucosa. Furthermore, an increase in the proportion of convolutions may reflect an increase in the rates of cell production and cell loss. In the group 3 convoluted mucosae the cytokinetic profile of the crypts resembled that of some of the flat avillous coeliac mucosae previously studied although the rates of cell production did not reach the levels attained by the most productive of the flat coeliac mucosae.


Adipose cell size in obese Africans: evidence against the existence of insulin resistance in some patients.

Aspects of adipose tissue cellularity were examined in 15 non-diabetic premenopausal African women with simple obesity living in Johannesburg. A smaller group of six non-obese Black women served as controls. Adipose tissue was obtained by biopsy from the deltoid, gluteal, and abdominal regions, and the mean fat cell size for each site was determined. Fasting plasma glucose, insulin, and lipid levels, and the glucose and insulin responses to a 100 g oral glucose load, in these subjects provided metabolic data for correlative analyses. As expected, the overall mean and regional adipocyte sizes were significantly larger in the overweight subjects. Significant regional variations in fat cell size were also seen, the gluteal region adipocytes being larger than those of other sites in both obese and non-obese women. A significant positive correlation was found between fat cell size and the percentage of ideal body weight. There was no significant relationship between adipocyte size, however, and any of the metabolic variables measured--notably basal or stimulated plasma insulin. Nearly half of the overweight women showed large adipocytes with normal plasma insulin concentrations. A proportion of African women with hypertrophic obesity do not appear to demonstrate any classical metabolic features of insulin resistance; this may be related partly to their high carbohydrate intake and unusual degree of physical activity. Our results do not, however, indicate that hyperinsulinaemia is completely absent in obese Black women.


An ultrastructural study of a nasal haemangioendothelioma.

A malignant haemangioendothelioma of the nose has been examined with the electron microscope. The tumour is predominantly poorly differentiated with only little evidence of its vascular ancestry identified. The cells are polygonal with a wide spectrum of organelles, including microfilaments. A conspicuous feature was the presence of cytoplasmic fenestrae developing into intracytoplasmic vacuolated spaces. The satisfactory progress of this patient is noted, and the value of electron microscopy in enabling an early and accurate diagnosis of this tumour to be made is emphasised.


Adjusted calcium conflict resolved? Differing effects on plasma total calcium of changes in plasma albumin after venous stasis or myocardial infarction.

Others have challenged the concept of adjusting total plasma calcium for albumin concentration on the grounds that after the application of a tourniquet the increase in calcium for a given increase in albumin differs significantly between normal individuals. We have confirmed this finding. In contrast, we have found that after myocardial infarction the fall in calcium for a given fall in albumin does not differ significantly between patients. Thus the adjustment of calcium for albumin using a single equation remains valid in patients with changes in albumin due to disease. We recommend that for consistent results blood should be taken with the minimum of venous stasis even though the patient's calcium is to be adjusted for albumin.


The skin as the source of Acinetobacter and Moraxella species occurring in blood cultures.

A study was made of the flora of the skin in hospital inpatients and healthy people to demonstrate the presence of non-fermenting Gram-negative rods of the Acinetobacter and Moraxella group. These organisms were found to be present on the skin of 34.3% of inpatients and occurred even more commonly in those patients with kidney disease. It was also present on the skin of 20% of a group of healthy members of staff. This rather high rate of skin carriage is thought to account for the not infrequent occurrence of this organism in blood cultures.


Class II (laminar flow) biological safety cabinet.

A microbiological survey of the effectiveness of class II (laminar flow) 'safety' cabinets found in the UK in the last six years is recorded. Only two of the nine units tested approached the containment of aerosols achieved by a good class I (exhaust protective) cabinet. The others were potentially hazardous if used with pathogenic material. The National Sanitation Foundation and the British Standards Institute have now laid down adequate specifications based on biological containment, and hopefully the conforming cabinets will be much better; even so, the purchase of a cabinet must be undertaken with care, and the cabinet requires frequent monitoring during use and after servicing.


HLA-linked C2 deficiency in a Dutch patient with systemic lupus erythematosus.

A patient with systemic lupus erythematosus was studied whose blood serum on repeated occasions showed undetectable levels of haemolytic omplement (C). A detailed investigation of individual C components in the serum of the proposita and her family revealed the absence of functional C2 in the patient and half-normal values in the relatives. C4 levels in the family, but not in the patient, were above normal, whereas the levels of factor B were low in all cases. No abnormalities were noted in C3, C9, or C1INH. Tissue typing showed linkage of the C2-deficiency gene with the HLA-A10/B18 and A9/B18 haplotypes. No linkage with red cell antigens and no relationship with plasma kallikrein levels was found.


Reactogenicity and immunogenicity of a surface-antigen-adsorbed influenza virus vaccine in children.

An influenza virus vaccine containing the purified surface haemagglutinin and neuraminidase antigens of A/Victoria/75 and B/Hong Kong/73 viruses adsorbed to an aluminium hydroxide gel was assessed for reactogenicity and immunogenicity in children aged 4 to 11 years, since there is no influenza virus vaccine available for this age group. Significant serum haemagglutination-inhibiting antibody responses to the A/Victoria/75 and B/Hong Kong/73 haemagglutinin antigens present in the vaccine were observed in 47% and 35%, respectively, of the children vaccinated, with a single dose. The vaccine induced no significant local or systemic reactions.


Bordetella bronchicanis (bronchiseptica) infection in man: review and a case report.

Bordetella bronchicanis is a common respiratory tract commensal of mammals. Rarely it causes whooping cough in children. Compromised adults in hospitals may be colonised, and one terminal pneumonia is on record. The fatal pneumonia of a malnourished alcoholic described here was contracted at home.


Radioimmunoassay of primary bile salts in serum.

Rapid, sensitive radioimmunoassays have been developed for the conjugated primary bile salts, cholate and chenodeoxycholate, using immunogens prepared by the mixed anhydride procedure. Antibodies produced showed equal specificity for glycine and taurine conjugates. Cross-reactivities were comparable with those from other published radioimmunoassays. The assays were routinely performed on unextracted sera and the concentrations correlated well with concentrations determined by gas-liquid chromatography. Accuracy, determined by the addition of bile salt to charcoal-extracted serum, and percision, determined by replicate analysis of a normal sample, were both less than +/- 10%. These figures are comparable with those obtained by both gas-liquid chromatography and other radioimmunoassays for bile salts. Normal sera were found to contain 0.49-1.32 mumol/l of cholate and 0.55-2.02 mumol/l of chenodeoxycholate. Serum concentrations in patients with liver disease were higher than this normal range. Three patients with mild liver distrubance were found to have one bile salt in the upper limit of normal, but in each case the other primary bile salt was outwith the normal range.


Measurement of serum primary bile acid ratio by gas liquid chromatography and radioimmunoassay.

The application of a sensitive gas liquid chromatography (GLC) assay has enabled patients in different diagnostic groups to be differentiated on the basis of the ratio of the primary bile acids, cholic: chenodeoxycholic acid. Because this method is unsuitable for a routine clinical laboratory, the primary bile acid ratio (PBR) is determined by radioimmunoassay techniques (RIA), and the results were compared with GLC analysis. RIA provided comparable results in control subjects and patients with large-duct obstruction, but significantly higher PBR values were found in cirrhotic subjects.


Performance of exhaust-protective (class I) biological 'safety' cabinets.

Nineteen open-fronted (class I) safety cabinets were subjected to spore containment and airflow tests, which suggested that a flow of 0.75 m/s was the minimum required for safe operation; further tests on three of the cabinets were repeated at different air speeds and confirmed this. The airflow is required to overcome the effect of laboratory or external air currents. Contamination of surfaces (including the operator's hands) by aerosols liberated inside the cabinets was investigated and found to depend more on turbulence within the cabinet (as from a restricted front opening) than on the number of air changes. The findings suggest that the product protection provided by a well-designed class I cabinet might equal that of a class II (laminar flow) unit.


Automated determination of red cell methaemoglobin reductase activity by a continuous-flow system for screening hereditary methaemoglobinaemia.

A flow diagram for the automated determination of ferricyanide reductase activity in red blood cells was prepared in the modules from AutoAnalyzer AA I (Technicon Instruments Inc). Ferricyanide reductase assay can be substituted for assay of cytochrome b5 reductase (EC 1.6.2.2), which plays a major role in reducing methaemoglobin in erythrocytes, and is defective specifically in the erythrocytes of patients with hereditary methaemoglobinaemia. The effective sampling rate of the analysis is 30/h, and less than 0.05 ml of whole blood is required. Interference of haemoglobin with absorption by potassium ferricyanide at 420 nm is effectively exculded by dialysis. This automated method was compared with the accepted diaphorase method, and it distinguished clearly the ferricyanide reductase activity of cord bloods from that of adult bloods. The activity of the blood from a patient with hereditary methaemoglobinaemia was only residual. It is suggested that the method is useful as a mass screening test for hereditary methaemoglobinaemia.


Electron microscopy of hepatitis B virus components in chronic active liver disease.

Eighteen liver biopsy specimens from patients with hepatitis B surface antigen (HBsAg) positive chronic aggressive hepatitis were studied by electron microscopy. All cases were selected on the basis of positive liver cell membrane fluorescence for HBsAg on immunohistochemical investigation. Striking changes in the morphology of the liver cell membrane were observed in nearly all cases. Furthermore, a dual aspect of hepatitis B core antigen (HBcAg) is described. HBcAg particles may occur as either 'naked' or 'cloudy' particles surrounded by semi electron dense material. The nature of the 'cloud' remains to be identified.


Female adnexal tumour of probable Wolffian origin.

Two further cases of 'female adnexal tumour of probable Wolffian origin' are described Both were retroperitoneal and presented a unique histology of uniformly close-packed bland spaces. solid islands, cords, and diffuse areas. A small hamartoma in a female fetus, part of which resembled the tumours, was traced to an area of near apposition with some paroophoron canals, providing further evidence of a Wolffian origin. The literature of this and some other putative Wolffian tumours is briefly reviewed, and the relation to rete adenomas is discussed.


The loci of stuttering: grammar or prosody?

Much of the research dealing with linguistic dimensions in stuttering has emphasized the various aspects of grammar, particularly as these aspects contribute to the meaning of utterances. However, data from several sources indicate that meaning and grammatical features are not likely to be the important language variables related to stuttering, but that stuttering occurrence is linked more closely to the prosodic dimension. The published literature in this area reports work done with English-speaking subjects; comparable material from other languages would be of considerable value to our understanding of linguistic determinants in stuttering.


Relative bioavailability of quinidine gluconate and quinidine sulfate in healthy volunteers.

A comparison of the bioavailability of quinidine sulfate to quinidine gluconate tablets in a single-dose randomized cross-over design with 20 healthy volunteers shows that the sulfate salt is more rapidly absorbed and provides significantly greater peak concentrations 1 hour after administration as compared to the peak levels achieved with the gluconate salt at approximately 5 hours after administration. When adjusted for the actual amount of quinidine contained in each tablet, there was no significant difference in the amount of quinidine bioavailable. Since quinidine gluconate absorption is significantly slower than quinidine sulfate, a combination of the two dosage forms may be utilized in providing the loading dose. Based on the computer modeling and the clinical data accumulated by this laboratory (unpublished) over the past four years, quinidine gluconate, in the dosage form utilized in this study, provides more constant blood levels with smaller differences between the Cpmax and Cpmin than the sulfate when administered every 6 or 8 hours. Further controlled clinical studies are needed to confirm these observations in patients.


Pharmacokinetics of phenobarbital following single and repeated doses.

Serum levels of phenobarbital, and also urinary excretion of phenobarbital and p-hydroxyphenobarbital, were examined after single and repeated oral doses of phenobarbital to three male subjects. Serum levels of phenobarbital at steady state were approximately ten times as high as those after a single dose. The overall elimination rate constant for loss of phenobarbital from serum, Kel, was significantly reduced after repeated doses, and Cmax infinity values calculated from single-dose data poorly predicted observed Cmax infinity values. Five-day urinary excretion of phenobarbital and p-hydroxyphenobarbital accounted for 16 and 21 per cent, respectively, of the initial dose. Due to extensive drug accumulation, 83 per cent of the final dose was excreted in five-day urine as phenobarbital and 85 per cent, as p-hydroxyphenobarbital. Comparison of plasma and renal clearances indicated that the rate of phenobarbital metabolism was reduced owing to repeated dosing, while the rate of urinary excretion of parent drug was unchanged.


The use of grammatical morphemes by normal and language-impaired children.

An examination was made of the grammatical morpheme usage of normal children and language-impaired children matched at two different levels of mean utterance length. The language-impaired children displayed less grammatical morpheme usage than the normal children with equivalent mean utterance length. However, no use of alternative features of semantic importance by the language-impaired children was noted, suggesting that no unique patterns for acquiring language were in operation. Instead, it appears that the language-impaired children may have attached less communicative significance to grammatical morphemes.


Developmental apraxia: diagnostic considerations.

This study compares the performance of developmentally apraxic children with that of children who have functional articulation disorders on a battery of diagnostic tests. Based on preliminary data, tests which assess auditory attention, auditory discrimination, auditory memory, oral-tactile feedback, and isolated and sequenced volitional oral movements appear to be useful in a differential diagnosis of articulatory defective children and, thus, warrant further study. Implications of these findings are discussed.


Interpretation of hematological and biochemical laboratory data in large-scale, multicenter clinical trials.

The laboratory assessment of drug tolerability is central to a long-term trial. But because of its volume, its multicenter origin, and the importance of nondrug factors, the analysis of these data is complicated. Various methods, i.e., collection of investigators' opinion, comparison of before- and after-treatment means, and analysis of transitions, were found to be unsatisfactory. A fourth method, described in this paper, seems to be more promising. An initial computer screening of the laboratory data is conducted to identify all patients with the potentially clinically relevant laboratory abnormalities. Each laboratory abnormally is then examined by the pharmaceutical physician with regard to the patient's sex and age, the trial diagnosis, concomitant and intercurrent illnesses, concurrent medication, unwanted effects, and other laboratory results, and each result is assigned a probable etiology according to a pre-defined classification system. By this method it is then possible to compare the frequency and severity of possible or probable drug-related laboratory abnormalities occurring with the various trial drugs. Our opinion regarding the importance of using this method would appear justified by the fact that a possible or probable drug effect was considered to have been responsible for only 15 per cent (112/760) of the potentially clinically relevant abnormal tests reported.


Communicative disorders at a health-care center.

The purpose of this study was to identify the prevalence of communicative disorders in a Children and Youth Program during the 5-yr period 1973-1977. It appears that the numerous speech and hearing surveys recorded fail to do the following: (a) identify speech, language, and hearing pathologie from a comprehensive health-care center and/or hospital; (b) study types of clientele longitudinally; (c) study prevalence and needs of minority groups specifically; and (d) study prevalence of communicative disorders in preshool children. For the Black community under study, it appears that the prevalence of communicative disorders is greater than reported in other surveys. In addition, the current study identifies a community not receiving services. In reviewing the facilities available to this socieconomic community, one finds inadequacies. These inadequacies may be reflected in manpower and equipment rather than programs and resources. The data indicate a tremendous need to expand available services.


Bulk laxative efficacy of a psyllium seed hydrocolloid and of a mixture of cellulose and pectin.

The cellulose/pectin combination (C/P) investigated in this study is as efficacious as a psyllium seed product widely used as a bulk laxative. Because of its physical characteristics (whiteness, lack of flavor and odor, lack of gelling upon standing), it is easy to use as a component of baked foods, sauces, drinks, stews, and in other recipes. Given its fecal bulking equivalence to the popular psyllium-based products, C/P offers advantages to the patient who takes a bulking agent regularly because of the wide choice of methods of consumption, ensuring better compliance over long periods of time. This cellulose/pectin combination appears to be a viable alternative to the limited choice presently available to the bulk laxative user and could also be used as a plant fiber supplement whenever this is desirable.


Color perception and deafness: college-level comparisons.

The performance of three groups of college-level subjects, deaf students, normal-hearing students, and Art students, were compared on nine tests involving color perception and color-verbal materials including (a) Color-Form Sorting, (b) Color-Form Pointing, (c) Color-Word Meaning, (d) Color-Pair Preferences (N=3), and (e) Color-Word Interference (N=3). Color perception differences between the deaf and the hearing groups were not substantiated: deaf and hearing groups differed only on tests involving verbal materials. The Deaf differed more from the Art students than from the Hearing.


Effects of clinician behaviors on acceptability of patients' responses in aphasia treatment sessions.

Records of the content of 40 videotaped samples of aphasia treatment sessions were prepared. These records were analyzed to determine (a) whether certain clinician behaviors and task characteristics are related to the occurrence of patient error responses in speech and language treatment sessions for aphasic individuals, and (b) whether "errors generate errors"; that is, whether error responses tend to occur in clusters rather than being distributed uniformly throughout the treatment session. The results of these analyses indicated that a number of event categories were significantly related to the occurrence of unacceptable patient responses. These results suggest that certain clinician behaviors generate patient error responses and also that clinicians tend to response to patient errors in characteristic ways. An analysis of these results also confirmed that unacceptable patient responses tended to occur in clusters.


An end to anxiety treating speech problems with rhetoritherapy.

The controversy over the connection between anxiety and nonproductive speech behavior can be resolved by taking note that alteration in behavior usually alters anxiety level. While many theorists recommend that treatment of anxiety will be beneficial, there is little contention that modification of anxiety alone alters skillful behavior. Rhetoritherapy is a mode of changing communication behavior through application of heuristics of problem solving and behavior change. Research studies tend to indicate a high level of success and selected case histories illustrate the process.


Wives' evaluation of problems related to laryngectomy.

Previous questionnaire studies of problems after laryngectomy have been directed toward the patients. In this study, 45 wives of laryngectomees were surveyed regarding their prior understanding of laryngeal surgery. The wives were also asked questions pertaining to health and physical care, and financial and social problems encountered after the operation. The survey results indicate a need for improved family counseling both before and after surgery.


Residual hypernasality in repaired cleft palate.

This article reviews selected components of the speech process in children with a repaired cleft palate in order to provide the speech-language pathologist with a framework for decision-making in the selection of appropriate identification and management strategies. Discussion is offered which intends to clarify the phenomena of velopharyngeal valving, nasality, and hypernasality. With an understanding of these fundamental phenomena, suggestions are proposed for management approaches which may be applied to the more common bases of hypernasality in children with repaired clefts.


The impact of a maternal and child health care program on the quality of prenatal care: an analysis by risk group.

A typical maternal and child health care program was implemented in an American Indian reservation community, and its impact on the effectiveness of prenatal care was assessed. Evaluation included examination from both the provider perspective (care provided to program users) and the population perspective (care received by a sample of all prenatal patients in the community), as well as examination of outcomes of prenatal care. The study cohorts were sorted into relatively high and average risk as a function of age, gravidity, and history of abortion or miscarriage. The study results suggest that such a program will improve the quality of prenatal care, although the program has a greater impact on the average risk group. Standard methods of assessing program effectiveness, which examine the care provided by the program as opposed to the care received by the community, will not detect this phenomenon.


Patients' percentions of physicians' behavior: determinants of patient commitment to the therapeutic relationship.

This study examines the hypothesis that patients decide to remain committed to their primary care physicians (or to leave them and "doctor shop") primarily on the basis of the "socioemotional" aspects of the physicians' behavior. It was hypothesized that physicians' demonstrations of caring for patients as people and their openness of communication would be predictive of patient commitment to the therapeutic relationship, and that the physicians' competence and role performance (including thoroughness of information gathering) as perceived by patients would be less important. Interviews were conducted with 342 inpatients and ambulatory patients in a large urban community teaching hospital after a visit with one of 38 house officers in internal medicine. Each patient was asked to (a) rate his or her physician on nine performance variables, (b) indicate his or her intention to return to that physician in the future or seek a different one, and (c) state his or her education, occupation, age, and present illness condition. The physicians' socioemotional behavior (caring and openness to communication), as well as their accessibility, tended to weight heavily in patients' decisions to continue the physician-patient relationship. In addition, the importance of some specific physician behaviors (for example, the physician's willingness to explain the medical condition) varied among subpopulations of patients.


The relative emphasis upon physician practice and organizational affairs of a consumer council in a prepaid group practice health plan.

This paper examines the topics of interest to a consumer advisory council in the Health Insurance Plan of Greater New York, a prepaid group practice. Data are derived from observations of consumer council meetings. Topics considered by the council dealt with (a) health plan services, (b) health plan structure, and (c) consumer council structure, process, and organizational role. The council was primarily interested in retaining and expanding existing services, facilitating utilization of services by enrollees, and achieving broader enrollee representation on the board of directors. These interests are directed toward the organizational context within which care is provided and do not relate to physician-patient encounters. Individual enrollees in prepaid group practice may be concerned with the physician-client relationship but consumer representatives are concerned only with the organization-client relationship.


Study of the precursors of ovine lactoproteins: primary structures of the 'signals' and enzymic processing of prelactoproteins by mammary microsomal membranes.

The radiolabelled primary translation products of ovine mammary mRNAs synthesized in a wheat germ cell-free system were isolated by immunoprecipitation and analysed by automated Edman degradation. The 3 'Ca-sensitive' caseins (alpha S1, alpha S2 and beta), kappa-casein, beta-lactoglobulin and alpha-lactalbumin were found to be synthesized as precursors with amino terminal extensions of 15, 21, 18 and 19 amino acid residues respectively. The extra pieces of these various lactoproteins are similar to 'signal' peptides of other secretory proteins in their length and hydrophobicity. The occurrence of an alanyl residue at the C-termini of the extra pieces of the 6 ovine prelactoproteins suggests that the mammary proteinase responsible for the cleavage of the signal peptides may have an elastase-like specificity. When mammary mRNAs were translated in a wheat germ cell-free system in the presence of mammary microsomal membranes, pre-beta-casein was converted into authentic beta-casein as demonstrated by amino terminal sequence analyses. Additionally, pre-beta-casein was post-translationally converted into authentic beta-casein by a specific proteinase(s) extracted from rough microsomes with Na deoxycholate.


Role of mammary casein kinase in the phosphorylation of milk proteins.

Casein kinase from lactating bovine mammary gland catalyses the transfer of the terminal phosphoryl group of ATP to specific serine residues in dephosphorylated caseins. Best substrates for casein kinase are the dephosphorylated proteins (bovine alpha S1- and beta-caseins and pepsin), unphosphorylated human beta-casein and the dephosphorylated peptide (residues 1-25) from bovine beta-casein. Results obtained with bovine and human beta-caseins indicate that the two serines underlined in the cluster Ser-Leu-Ser-Ser-Ser are particularly susceptible to the action of casein kinase. Since a similar sequence is found in dephosphorylated alpha S1-casein, it is probable that serines in this region of alpha S1-casein are also phosphorylated. The results support the concept that certain serines in casein are particularly susceptible to phosphorylation by casein kinase.


The carbohydrate portions of milk glycoproteins.

kappa-Casein is the main glycoprotein of cow's milk. Its polysaccharide part is O-glycosidically linked to threonine residue 133. It contains only 3 different sugars (Gal, GalNAc, NeuNAc), but a microheterogeneity has been detected at the sugar level. Two main polysaccharides have so far been characterized. The structure of the trisaccharide is NeuNAc alpha 2 leads to 3 Gal beta 1 leads to GalNAc; the tetrasaccharide contains one additional sialic acid. The polysaccharide part of ovine kappa-casein resembles that of bovine kappa-casein, but contains also N-glycolyl neuraminic acid. Human kappa-casein contains 3 times more carbohydrate than bovine kappa-casein with 2 additional sugars, GlcNAc and Fuc. The various polysaccharide parts isolated from bovine colostrum kappa-caseinoglycopeptide are much more complex than those obtained from the normal glycopeptide, indicating an evolution of the sugar part as a function of time after parturition. Some aspects of the secondary structure of kappa-casein and the role of the sugar part are discussed. The carbohydrate moiety of another milk protein, human lactotransferrin, is also discussed briefly. it is comprised of 2 identical glycan groups, N-glycosidically linked to the protein, and quite different from the kappa-casein carbohydrate moiety.


Comparative aspects of milk proteins.

The current status of knowledge of the major proteins of milks of various species is evaluated. Most of the non-bovine milk proteins are homologous with the recognized families of those of Bos taurus, alpha S1-caseins, alpha S2-caseins, beta-caseins, kappa-caseins, beta-lactoglobulins, and alpha-lactalbumins, each family representing a separate genetic locus specific to the mammary gland. No prominent milk protein not homologous to one of these families has yet been discovered in milk of any species. Genetic polymorphism resulting from substitutions in the polypeptide chains and various degrees of post-translational phosphorylation, glycosylation, and proteolysis have been identified in milk proteins of several species. Total protein production ranges among species from about 0.5 to 10 g/d per kg0.75 maternal weight. Proportions of the several proteins vary greatly among species, but few accurate analytical data are available except for total casein and total whey protein contents.


A genetic and biochemical analysis of a polymorphism of bovine alpha S2-casein.

Using gel electrophoresis a genetic polymorphism of alpha S2-casein (Cn) was discovered in individual milk samples from 2 bovine breeds of the eastern part of France (Vosgienne and Montbéliarde). The 3 observed phenotypes (Plate 1) are determined by 2 co-dominant alleles at an autosomal locus. The alpha S2-Cn A variant was the only one known up to now in European breeds (reference variant) and alpha S2-Cn D is a new variant, whose bands overlap the beta-casein A band at pH 8.6, and migrate faster than alpha S2-Cn A at pH 3.0. The sequence of the polypeptide chain alpha S2-Cn D differs from that of alpha S2-Cn A by the deletion of a very acidic nonapeptide, which includes a cluster of 3 phosphoseryl residues. Due to the characteristics of the reference sequence, this deletion cannot be exactly located but it involves residues 50-58, or 51-59, or 52-60. A genetic analysis shows that locus alpha S2-Cn is closely linked to the cluster alpha S1-Cn--beta-Cn--kappa-Cn. The 4 casein species are thus synthesized by 4 closely linked loci.


The formation and structure of some proteose-peptone components.

Two constituents of the proteose-peptone fraction of bovine milk have been isolated and characterized. Component 5 (PP5) has been shown to represent residues 1-105 and 1-107 of the beta-casein amino acid sequence, while component 8-fast (PP8F) corresponds to residues 1-28 of beta-casein. Thus, these proteose-peptones represent the N-terminal portions of the beta-casein molecule, produced by proteolytic cleavages which form the gamma 1, gamma 2 and gamma 3-caseins from the C-terminal part. The continuing formation of the total proteose-peptone fraction, PP5, PP8F and the gamma-caseins during storage of raw milk at 18 or 37 degrees C has been also been demonstrated.


The formation of gamma-caseins during cooling of raw milk.

It has been shown that there is a time-dependent transfer of beta-casein and the milk serine proteinase system from micelles to milk serum with change of temperature from 38 to 4 degrees C. It has been established that the gamma-caseins can be formed by proteolytic degradation of beta-casein. By a simple extraction technique, the very hydrophobic gamma-casein fraction was separated from stored milks (26 and 4 degrees C) and estimated quantitatively. The results showed that the proteolytic degradation of beta-casein is faster at 4 degrees C than at room temperature and this can be explained by the immobilization of enzyme and substrate at the micelle surface at higher temperatures (26 degrees C). The results indicate that irreversible changes during cooling for short periods do not cause problems in milk processing, but the formation of gamma-caseins and phosphopeptides may influence the technological properties of raw milk stored for more than 48 h.


Model proteolysis of beta-casein by immobilized trypsin.

The enzymic degradation of beta-casein by immobilized trypsin is described and its use as a model system to study proteolytic reactions which occur in milk during processing is examined. Quantitative determination of proteolysis can be obtained by densitometric transmission measurement of patterns obtained by polyacrylamide-gel electrophoresis. Staining properties of some of the individual components in the electrophoretic patterns were determined by calibration with pure protein and peptide preparations. The isolation of pure beta- and gamma-caseins and the preparation of several forms of immobilized trypsin are outlined.


Proteolytic activity in UHT-sterilized milk.

The proteolytic activity in UHT-sterilized milk of a proteinase-containing fraction, prepared from the milk, is reported. The proteinase fraction was isolated from casein micelles as described by Reimerdes & Klostermeyer (1974). The fraction was added to UHT milks and the proteolysis in the samples, measured as the liberation of non-protein nitrogen, compared with that in control samples without added proteinases. The increase in proteolytic activity and deterioration in samples containing added proteinases indicates that an enzyme process occurred in UHT-sterilized milk which could influence gel formation.


Buffalo alpha S0-casein: isolation and characterization.

A method for the preparation of alpha S0-casein, and for the preparation of alpha S1-casein fractions 1 and 2 from buffalo casein are described. The amino acid composition and phosphorus content of alpha S0-casein are given and compared with those of other alphaS-caseins.


Human beta-casein.

Human beta-casein occurs in multiphosphorylated forms having the same amino acid composition but with 0-5 phosphate groups/molecule. Sequence analysis was used to determine whether each of the phosphorylated forms is a mixture of species having a certain number of phosphate groups randomly distributed or whether each form contains phosphate groups on specific seryl or threonyl residues. It was found that forms containing 2, 4 and 5 phosphate groups/molecule are homogeneous with respect to their phosphorylation sites. The monophosphorylated form, however, is a mixture of equal amounts of species phosphorylated at residues 9 or 10.


Association of proteins.

A review is presented of the various intermolecular forces important in stabilizing protein structure and association. Emphasis is put on entropic as well as enthalpic contributions to the free energy. The factors affecting size and size distribution in protein aggregates are discussed. A theory is presented for the size distribution of casein micelles, taking into account the spherical nature of the micelles and the importance of surface repulsive forces in limiting size.


Quantitation of alpha S1-casein aggregation by the use of polyfunctional models.

A model for the coagulation of Ca2+ alpha S1- caseinate is described wherein the casein molecules are considered to aggregate as polyfunctional units. The functionalities on the protein molecules are produced as a consequence of the binding of Ca2+, and the multiple equilibria which are established during this binding produce a distribution in which not all casein molecules have the same functionality. The theory is compared with experimental data of the precipitation reaction, and is shown to provide an adequate quantitative description of the precipitation.


The kinetics of the precipitation of chemically modified alpha S1-casein by calcium.

The aggregation of alpha S1-casein by Ca is viewed as resulting from a reduction in the net negative charge by the binding of positively charged Ca2+. This reduction in charge leads to the equivalent of isoelectric precipitation. A quantitative relationship between the rate of aggregation of the casein and the monomer net charge is predicted in this isoelectric precipitation model. Precipitation  results are presented for alpha S1-casein labelled with dansyl chloride. Providing the changes in charge brought about by the modification are taken into account, the precipitation behaviour of these caseins can be reconciled with that of native alpha S1-casein. This emphasises the role of electrostatic repulsion in this process and lend further support to the isoelectric precipitation model.


On the size of monomers and polymers of beta-casein.

The size and number average molecular weight have been determined for beta-casein monomers and polymers from electron micrographs using the freeze-etching procedure with spray-frozen specimens. For the spherical beta-casein monomers we found a mol. wt of 22600 and a diam. about 10 nm, which compared quite well with data obtained from ultracentrifugation, light scattering and viscosity measurements. Polymer sizes were in agreement with molecular weight determinations from ultracentrifugation and light scattering, assuming that the volume and weight of the particles are proportional.


Structure of beta-casein.

The temperature and concentration dependent association of beta-casein was studied by means of viscometry, gel filtration chromatography, electron microscopy, analytical ultracentrifugation and UV difference spectrophotometry. Degrees of polymerization of 12, 22 and 49 and free energies of association of -21, -23 and -25kJ/mole monomer were found at temperatures of 10, 15 and 20 degrees C respectively in 0.2 M Na phosphate buffer pH 6.7. Monomeric beta-casein was not a completely random coil but became more compact with increasing temperature, due to hydrophobic interactions.


Casein micelles: the colloid-chemical approach.

The colloidal properties of micellar casein are reviewed. It is shown that behaviour of intact micelles is much at variance with the predictions from the Schulze-Hardy rule, and that therefore their stability cannot be explained by the principles of the DLVO theory. Towards electrolyte, micelles behave as a protein rather than a lyophobic colloid. Casein is a strong protective colloid. In the micelle, however, it does not completely cover the inorganic constituent which remains sensitive to changes in the ionic environment. The rate theory of the enzyme-induced clotting of casein micelles is summarized. It is shown that the lag phase in the clotting is due to the second order of the co-agulation reaction. Flocculation rate constants of micelles have been deduced from clotting times. Their relatively low values can be attributed to an orientational constraint. Practical consequences of the theory with respect to clot structure, gelation of sterilized products and cheese manufacture are discussed.


Developments in column chromatography for the separation and characterization of casein micelles.

Skim-milk was fractionated by permeation chromatography on CPG-10 (300 nm) at 20 degrees C with synthetic milk serum. The elution profile, which was highly reproducible, showed 3 partly resolved peaks. On treatment with 0.1% glutaraldehyde before chromatography, a similar profile was obtained indicating no appreciable micellar dissociation during chromatography of the milk. The casein composition of the eluent fractions, determined by quantitative chromatography on hydroxyapatite, showed that 12.1% of total casein was associated with the low molecular weight peak. The micelle content of beta- and kappa-casein increased with increasing elution volume, and the alphas/kappa ratio showed a progressive diminution from 4.3 to 2.3. Large differences were found in the colloidal phosphate contents and the weight average diameters of the micelle fractions which clearly show that CPG-10 fractionates on the basis of molecular size.


CPG-chromatography studies of the stability of casein micelles.

Casein micelles fractionated on controlled pore glass (CPG-10/3000) were shown to be stable by recycling experiments. Only minor effects on the size distribution of the casein micelles were found after heating skim-milk to 100 degrees C for 10 min, or freeze-drying skim-milk at -70 degrees C followed by resuspension in the synthetic milk serum of Jenness & Koops (1962). The heating caused some whey proteins (beta-lactoglobulin) to enter the micelle fractions while the freeze-drying caused some of the largest micelles to disrupt. In colloidal calcium phosphate-free skim-milk prepared according to Pyne & McGann (1960) all the micelles appeared to dissociate into monomeric caseins.


The voluminosity of bovine casein micelles and some of its implications.

A comparison of literature results on the voluminosity of casein micelles yields large differences, largely related to the method of determination. After applying some corrections, methods based on hydrodynamic radius yield a value of roughly 3.9 ml/g dry casein, other methods (microscopy, sediment volume) about 2.2. Roughly half of the discrepancy can be explained by the micelles being not perfectly spherical. To explain the remaining difference, it is assumed that the micelles are hairy, i.e. they have molecular chains protruding into the milk serum. The hairyness would increase with decreasing temperature and be largely removed by the action of rennet. It would cause some entropic repulsion between micelles at close approach.


Hydration of casein micelles: kinetics and isotherms of water sorption of micellar casein isolated from fresh and heat-treated milk.

Water vapour sorption isotherms of casein micelles prepared from raw milk and various heat-treated milks were determined. The equilibrium water contents of the heated preparations were markedly lower than that of the raw-milk casein over the whole range of vapour pressures studied. An analysis of the sorption isotherms in the relative vapour pressure range 0.1--0.45, according to the Brunauer, Emmett & Teller (1938) equation, showed that there were significant differences between preparations in the computed monolayer contents. Differences in the rates of water sorption were also observed between the different preparations. As judged from the amount of absorbed water, the influence of the heating methods could be ranked in the order: HTST (92 degrees C) approximately UHT (direct) less than UHT (indirect) less than HTST (72 degrees C).


The role of calcium, phosphate and citrate ions in the stabilization of casein micelles.

To obtain greater insight into the interaction of Ca, citrate and phosphate ions with casein, 31PNMR measurements were performed on combinations of these ions with alphas- and kappa-caseins. It was found that addition of alphas-casein to a Ca phosphate solution in D2O at 27 degrees C and pD 6.4 resulted in a downfield shift of the 31P singlet. An almost identical shift was observed with kappa-casein, but no shift was found when only phosphate ions were present or when Ca2+ were added to phosphate ions in the absence of casein. Separate experiments with poly-L-lysine, mol. wt approx. 35,000, resulted in similar downfield 31P chemical shifts of Ca phosphate as with both caseins, whereas no shift was observed when poly-glycine was added. From these results it can be concluded that Ca and phosphate ions associate with casein in a co-operative manner, probably in the way described by ter Horst (1963) as a complex with the NH3+-groups of lysine or arginine in a structure such as: (casein--NH3+)--PO43---Ca2+. The formation of this complex may be enhanced by citrate ions, since preliminary results have shown that addition of Na citrate to a solution of alphas-casein with added Ca phosphate produces a broadening of the 31P signal as well as a chemical shift.


The binding of beta-casein to hydroxyapatite: the effect of phosphate content and location.

The elution behaviour of beta-casein from columns of hydroxyapatite has been studied and the effect examined of the enzymic addition of an extra phosphate residue. When the additional phosphate is located near pre-existing phosphate residues stronger binding to hydroxyapatite is observed. When the additional phosphate is remote from the pre-existing phosphates no increase in strength of binding is observed. It is suggested that the clustering of phosphate residues which characterizes alphas- and beta-caseins can be rationalized on the basis that it facilitates co-operative interactions between these phosphates and the Ca phosphate of the casein micelle and/or basic residues within casein polypeptide chains.


Sub-structure of synthetic casein micelles.

Casein micelles of different composition were synthesized in various ways and their sub-structure was investigated with the electron microscope by means of thin sections. Earlier studies of Schmidt et al. (1974) using the freeze-fracturing technique had shown no differences in the sub-structure of natural micelles and artificial micelles containing Ca and casein only. Contrary to these results our present studies showed that for the production of synthetic casein micelles with the same sub-structure as the natural ones it is necessary to add at least 2 other ions to the casein solution besides Ca2+: these are phosphate and citrate. The citrate ions play an important role in forming the material of the dark framework of the micelles visible in electron micrographs of unstained thin sections. This supports the hypothesis of Pyne & McGann (1960) that casein micelles contain a citrate apatite.


Properties of artificial casein micelles.

A survey is given of the relationships between various properties of artificial casein micelle systems and their composition with respect to alphas1-, beta and kappa-casein, colloidal phosphate and citrate. Properties investigated were: the amount of colloidal phosphate, the micellar size, and the stability of the micelle towards dialysis, pressure, ethanol and heat.


Heat stability in concentrated and non-concentrated milks--the effect of urea and beta-lactoglobulin levels and the influence of preheating.

Heat stability as a function of pH has been studied in concentrated and non-concentrated milk systems. The influence of preheating has also been examined. The concentration of beta-lactoglobulin has been shown to affect markedly the heat stability behaviour in both systems but with different characteristics. Increasing the level of urea resulted in increased heat stability in non-concentrated milks, but corresponding concentrated milks showed a small decrease in maximum heat stability. It has not been possible to extrapolate heat stability data from non-concentrated to concentrated milks.


Stability of buffalo casein micelles.

Buffalo skim-milk is less heat stable than cow skim-milk. Interchanging ultracentrifugal whey (UCW) and milk diffusate with micellar casein caused significant changes in the heat stability of buffalo casein micelles (BCM) and cow casein micelles (CCM). Buffalo UCW dramatically destabilized CCM, whereas buffalo diffusate with CCM exhibited the highest heat stability. Cow kappa-casein stabilizes alphas-casein against precipitation by Ca better than buffalo kappa-casein. About 90% of alphas-casein could be stabilized by kappa:alphas ratios of 0.20 and 0.231 for cow and buffalo, respectively. Sialic acid release from micellar kappa-casein by rennet was higher than from acid kappa-casein in both buffalo and cow caseins, the release being slower in buffalo. The released macropeptide from buffalo kappa-casein was smaller than that from cow kappa-casein as revealed by Sephadex gel filtration. Sub-units of BCM have less sialic acid (1.57 mg/g) than whole micelles (2.70 mg/g). On rennet action, 47% of bound sialic acid was released from sub-units as against 85% from whole micelles. The sub-micelles are less heat stable than whole micelles. Among ions tested, added Ca reduced heat stability more dramatically in whole micelles, whereas added phosphate improved the stability of micelles and, more strikingly, of sub-micelles. Citrate also improved the heat stability of sub-micelles but not of whole micelles.


Peritoneal dialysis clearance of endogenous lactate.

Four patients with severe lactic acidosis were treated with peritoneal dialysis using a bicarbonate-buffered dialysate. Peritoneal dialysis clearance of lactate averaged 9.1 ml minute, and the total lactate removed during dialysis ranged between 88 and 352 mEq. Removal of excess lactate by dialysis contributes to the control of acidosis and prevention of alkalosis once the metabolic defect is reversed.


Standards for accurate in vitro characterization of dialyzers: test case the Vivacell.

A standard format is proposed for cataloging dialyzer transport data in order to improve communication and understanding of published results. The need for such a format is obvious from the ambiguity and lack of uniformity in published data. This report for in vitro characterization also describes an adequate experimental set-up for proper dialyzer characterization and an improved means for reporting uncertainty where curve fitting techniques are employed. The Vivacell dialyzer has been evaluated by these means as the first test case.


The use of behavior modification techniques for the treatment of hemodialysis patient non-compliance: a case study.

This study concerns a renal patient who was non-compliant to staff requests to monitor his blood clotting times. The non-compliant behavior was resolved within six treatment sessions through the combined use of contracting, shaping, stimulus control, discrimination training and social and material reinforcement. Follow-ups at 30, 60 and 90 days revealed a high degree of patient compliance and accuracy in taking and recording his blood clotting times. Implications for behavior modification techniques in the field of hemodialysis are briefly discussed.


Dialysis of middle molecules at pulsatile flow.

Pulsatile flow was used in a continuous flow flat-plate dialyzer in order to achieve the more efficient removal of middle molecules. The solutes ranged in the molecular weights from 342 (sucrose) to 1355 (vitamin B-12). The permeability of Cuprophane membrane to sucrose, raffinose and vitamin B-12 were calculated both for pulseless and pulsatile flows. It was found that pulsatile flow is more favorable than steady flow with regard to increase of membrane permeability. However, as the solute molecular weight increases, fluid-phase resistances become relatively less important and the transport rate becomes dominated by the membrane properties.


Hemodialysis for methanol intoxication.

A patient with toxic levels of methanol was hemodialyzed while receiving an ethanol infusion. It was demonstrated that during the dialysis significant quantities of both ethanol (17.70 gms) and methanol (26.69 gms) were extracted. Also, it was shown that the ethanol did not competetively inhibit the extraction of the methanol. Since ethanol is removed in significant quantities during dialysis, one should increase its infusion rate during hemodialysis and decrease the rate when the patient is not being dialyzed. This would achieve adequate and constant blood levels of ethanol and would satisfactorily inhibit the metabolism of methanol by the liver.


The work of worrying in children undergoing surgery.

This study examined the relationship involving children's level of anxiety, defensiveness, and play patterns 1 week prior to, during, and 1 week after hospitalization for minor surgery. A 7-month follow-up was also conducted in order to assess the children's recall for hospital events and coping style. The results suggested that two classes of children could be identified. The children in one group distinguished themselves in terms of their disposition to engage in the "work of worrying" (i.e., were low defensive prior to hospitalization, actively played with stress-related toys prior to hospitalization, and reported minimal distress and anxiety following surgery). Those in the second group were highly defensive, avoided playing with stress-related toys, and reported most anxiety following surgery. The parallel between children and adults patterns of dealing with surgery was considered in terms of Janis's (1978) model of coping with psychological stress.


Comparing psychological and pharmacological treatments for hyperkinetic boys and their classmates.

This study compares the short-term effects of methylphenidate and of teacher consultation on the on-task behavior of diagnosed hyperkinetic outpatient boys and selected classmates. Statistically significant treatment effects were found for both drug-treated and behaviorally treated hyperkinetic boys; the size of these effects did not differ between the two types of treatment. Within the behavioral group, the treatment effect spilled over, so that there was also a significant treatment effect on overactive classmates of the behaviorally treated hyperkinetic children and a trend toward a significant treatment effect on their average classmates. Some implications of the findings are discussed.


The acute effects of caffeine on evoked response, vigilance, and activity level in hyperkinetic children.

Seventeen hyperkinetic children who had previously responded to sympathomimetic amines were given three different dosages of caffeine in counterbalanced order (placebo, and low and high doses equivalent to one and three cups of coffee). One hour following ingestions they were tested, double-blind on measures of visual evoked response, alpha time, vigilance, and activity level. There was a significant effect on evoked response. The behavioral measures tended to be affected in a dose-related manner but not to a statistically significant degree. It is concluded that although centrally active, caffeine does not show the congruence between behavioral and central effects that other stimulants useful in behavioral management have shown.


Cognitive, social, and other correlates of specific reading retardation.

Children with specific reading retardation were matched with controls on the basis of age, sex, intelligence, and (less successfully) parental education. All subjects were tested on a variety of automated performance tests including the Matching Familiar Figures (MFF) Task, Auditory-Visual Integration, Short-Term Memory, the Continuous Performance Task (CPT), and Motor Performance. All children were assessed socially using the Conners Teacher Questionnaire, and reading-retarded children were rated on the Behavior Problem Checklist. Finally, all children were screened with the Finger Twitch Test and were assessed for left-right awareness. Statistical analysis suggested that the following performance tests discriminated between the groups in this respective order of importance: MFF (Accuracy), Auditory-Visual Integration, and the CPT. The Short-Term Memory Task, MFF Decision Time, and Motor Performance did not distinguish between the groups. Multiple regression equations suggested that scores on the performance tests could account for about 40% of the variance in reading attainment. Several factors from the rating scales (notably those pertaining to attention and anxiety) and left-right awareness also discriminated between the groups.


Types of private speech produced by hyperactive and nonhyperactive boys.

Types and amount of private speech (audible talking that is not addressed to another person) were assessed during the free play of 16 hyperactive and 16 nonhyperactive boys. Verbalizations were coded into nine categories that denoted the boys' level of use of verbal control of their own behavior (Luria, 1961; Kohlberg, Yeager, & Hjertholm; 1968). Differences in amount and type of private speech between hyperactive and nonhyperactive boys were found to indicate that hyperactive boys may be presenting a specific or general cognitive lag in development. Treatment ramifications are discussed.


Rating scales for hyperactivity: concurrent validity, reliability, and decisions to label for the Conners and Davids Abbreviated Scales.

Rating scales have become the instrument of choice in labeling and assessing change in behavior of hyperactive children. However, several criticisms have recently have levied against their use. The present investigation examined the concurrent validity, and inter- and intrarater reliability for the Abbreviated Teacer Questionnaire (ATQ, Conners, 1973) and the Rating Scales for Hyperkinesis (Davids, 1971). Sixteen teachers from two special and two regular schools (grades 1-4) rated 211 normal and 49 special children using both scales. High correlations were found suggesting excellent predictability between scales and considerable stability across time and rater. Lower scores on a subsequent rating relative to an initial rating were demonstrated, dependent on time between ratings but independent of (a) teacher expectation of treatment gains, (b) bias produced by rating selected children, and (c) whether children were hyperactive or normal. Use of initial and infrequent rating scores versus subsequent, closely spaced ratings was related to the rater's objective (e.g., diagnosis, treatment, or assessment).


Personality patterns of adolescent poor and good sleepers.

To determine whether poor sleepers have a unique personality constellation significantly different from that of good sleepers, a sample of 162 emotionally disturbed adolescent poor sleepers was compared to a sample of 153 emotionally disturbed adolescent good sleepers on standardized personality instruments. Poor sleepers were found to have a high incidence of neurotic psychopathology with personality patterns characterized by depression, fearfulness, inhibition, anxiety, and rumination. In contrast, good sleepers showed quasi-healthy and/or characterological patterns. While this study does not resolve cause and effect relationships, it does establish a highly significant relationship between neuroticism and sleep disturbance for adolescent boys and girls, and also demonstrates a similarity of personality dynamics and patterns between adult and adolescent samples of patients with sleep disturbances.


Developmental recall lag in learning-disabled children: perceptual deficit or verbal mediation deficiency?

To investigate the development of mediational deficiencies in verbal and nonverbal visual short-term memory of learning-disabled children, the recall task of Atkinson, Hansen, and Bernback was administered to learning-disabled children in two experimental conditions. In Experiment 1 no significant differences on nonverbal short-term memory recall between normal and learning-disabled children were found. Similar recall responses (e.g., middle response bias, primacy effects, and recency effects) were found for both groups. Nonverbal recall was comparable for disabled and normal children as suggested by stimulus content and association scores. Experiment 2 found that while the effects of overt rehearsal on pretrained labels on learning-disabled children's recall was negligible, labels provided superior recall for normal children. Results suggested that learning-disabled children suffer from a verbal mediational deficiency consistent with Flavell's (1970) mediation deficiency hypothesis.


Behavior change in children at a therapeutic summer camp as a function of feedback and individual versus group contingencies.

Two contigency systems, individual and group, were evaluated for their effects on children's behavior during small group meetings. Forty-eight children, ages 8 through 14, attended a 7-week residential camp program operated on a token economy system. Ratings of the campers' behavior were made by the counselors on a 5-point rating scale at the daily meetings. Each camper received both contingency programs, in counterbalanced order. Data were gathered during baseline, two feedback and two treatment phases. An analysis of variance for repeated measures was performed on the mean weekly camper scores. The two systems were equally effective in significantly increasing the amount of desirable behavior, and there was no effect on behavior due to feedback alone. The results are discussed in terms of advantages and disadvantages of each type of contingency system, with some suggestions made regarding areas of further investigation.


Dimensions of problem behavior in deaf children.

The Behavior Problem Checklist was completed by the teachers of 192 deaf students who attended a special day school for the deaf. Three separate factor analyses were performed. Four factors that correspond to the dimensions found in earlier research and previously labeled conduct disorder, personality problems, immaturity-inadequacy, and socialized delinquency were found. An additional factor labeled passive inferiority was also extracted.


Measurement of the potency of pollen extract by radioimmunoprecipitation.

We describe a novel procedure for standardization of allergen extracts using radioiodinated crude extracts. Radiolabeled extracts were reacted with immunoglogulin E (IgE) antibody, and the resulting complexes precipitated by anti-IgE. Experiments with ragweed pollen, grass pollen, honeybee venom, and Alternaria extracts revealed that 1% to 14% of the radioactivity was precipitated, these percentages ranged from 2 to 20 times blank values. Binding of labeled ragweed extracts to IgE antibody could be inhibited by unlabeled extracts and linear inhibition responses could be derived. The potencies of 11 short ragweed extracts were ranked by their inhibitory capacities in such an IgE radioimmunoprecipitation (RIP) test and compared to potencies determined by radioallergosorbent test (RAST) inhibition; these were related, rs = +0.97 (p less than 0.001). Labeled extracts were also reacted with IgG antibodies, and the resulting complexes were precipitated by anti-IgG. From 1% to 34% of the radioactivity associated with the various extracts was precipitated by anti-IgG, and these percentages were from 2 to 20 times blank values. The reaction of IgG antibody with radiolabeled pollen extracts could be inhibited by unlabeled extract, and in the case of short ragweed the measurements of potencies using IgG and IgE antibodies were correlated, rs = +0.96 (p less than 0.001), suggesting that similar determinants were recognized by both IgG and IgE classes. The RIP procedure provides an alternative to the RAST for the standardization of allergy extracts and eliminates the need for affinity chromatography-purified antibody to IgE.


Nasal challenge testing in grass pollen hay fever.

Nasal sensitivity to rye grass pollen allergens was evaluated by provocation testing in patients with hay fever due to grass pollen using measurements of nasal airways resistance (NAR), a reproducible system for delivery of allergen, and stringent criteria for allergen storage. Reproducibility was assessed in 24 subjects with hay fever by nasal provocation with serial dilutions of Lolium perenne allergens on 3 occasions: during the grass pollen season, immediately after the season, and in early winter. Threshold doses of allergen required to double the saline control NAR or to provoke persistent sneezing and rhinorrhea were slightly higher 1 mo after the pollen season, but there was no significant differences between threshold doses during the pollen season and 8 mo later. When the threshold doses during challenges were exceeded, there were late reactions in 4 of 24 patients. Normal subjects and patients with perennial rhinitis and with negative skin tests to L. perenne extract were unresponsive in nasal challenge tests.


Streamlining and implementing nutritional assessment: the dietary approach.

Early methods of assessing food intake were developed to provide nutrition services for individuals in health care. Dietary methodologies increased in number and complexity as they were used in nutrition surveys of populations and as tools for nutrition research. Recent expansion of community health programs with nutrition components, and greater emphasis on nutritional assessment in health care require the use of streamlined methods of dietary inquiry and screening. The specialized knowledge and skills of the nutritionist/dietitian are best reserved for persons identified through screening as being at high risk for malnutrition.


Nutrient analysis of Exchange Lists for Meal Planning. I. Variation in nutrient levels.

Using available food composition data, individual Exchange Lists within the revised Exchange Lists for Meal Planning were evaluated for calories; protein; fat; calcium; phosphorus; iron; sodium; potassium; vitamin A; thiamin; riboflavin; niacin; ascorbic acid; saturated, oleic, and linoleic fatty acids; cholesterol; and crude fiber. Mean values, standard deviations, and ranges are reported for the above nutrients. Mean values agreed well with those suggested in the booklet for grams of carbohydrates, protein, and fat and for calories for all lists except milk. However, a wide range in values exists for food within each Exchange List.


Nutrient analysis of Exchange Lists for Meal Planning. II. Nutrient density food profiles.

Nutrietn density profiles, generated for the individual subgroups within the revised Exchange Lists for Meal Planning, are presented. The authors suggest that the profiles would be useful for educational purposes.


Weight loss over time. Concomitants and consequences of a decreasing rate.

A decelerating rate of weight loss occurred among women participating in a community-based weight-control program. The rate of change may be due to greater food intake or to change in the level of fluid loss, in metabolic rate, and/or in the amount of physical activity. As these changes may affect motivation to persevere, they should be explained at the start of treatment, and program participants should be encouraged to maintain a gradually increasing level of physical activity. Disillusionment with the failure to sustain the initial rapid weight loss may be a factor that better predicts attrition than the demographic, personal history, or psychologic factors that have previously been studies.


Protein quality of several multi-component, commercially prepared foods.

Eleven commercial food products that may be considered by consumers to be major sources of protein were evaluated. Most of these items contained significant amounts of carbohydrate in the form of cereal products or purified sugars. Seven of the products were at least equal to casein in protein efficiency ratio (PER). Canned spaghetti and meat balls, the TV dinner, canned chicken-and-vegetable baby food, and food bars had PER values between 91 and 73 per cent of that of casein, while PER values for ground beef and high-protein cereal were significantly higher than casein.


Dietary management of patients with diabetes treated by hemodialysis.

Early experience with the treatment of patients with insulin-dependent diabetes and renal failure by chronic hemodialysis indicated a high mortality and increased incidence of medical complications. Since 1972, a marked improvement in survival and reduction in incidence of complications has been attributed to more rigorous control of fluid overload, hypertension, and blood sugar levels by insulin therapy and careful dietary management. A diet has been developed which combines the diet used by dialysis patients with suitable modifications for the insulin-dependent patient with diabetes. The importance of patient education is stressed in an attempt to improve patient compliance.


Comparison of mortality rates for various surgical operations according to age groups, 1951-1977.

A comparison was made of the mortality rates for various surgical operations, by age groups and by time periods. The age groups were: under 60, 60-69, 70-79, and 80 or over. The three time periods were: 1951-1955, 1956-1967, and 1967-1977. Only slight improvement was noted in these mortality rates despite the fact that during the 1951-1977 period many improvements were made in anesthesia, surgical techniques, antibiotic therapy, intensive-care units, and presumably the better understanding of disease. Further improvements will depend almost exclusively upon studying the basic problems of old age, chiefly atherosclerosis with its effects on the heart, blood vessels, brain, respiratory system and urinary tract. Unless this is done, there is no prospect of great improvement in operative results, and no basis for believing that the operative risk in the aged is the same as in the young. Unless the physiologic reserves of the aged can be improved, the surgical mortality rates likely will remain static.


Fluphenazine enanthate in the outpatient treatment of late paraphrenia.

Fluphenazine enanthate parenterally was compared to an antipsychotic drug (haloperidol) given orally for the "crisis intervention" treatment of elderly outpatients with late paraphrenia. In the fluphenazine group, 11 of 13 patients improved, compared to only 3 of 13 in the oral drug group (p less than 0.01). The superiority of fluphenazine probably was attributable to improved compliance with the prescribed regimen by patients receiving parenteral depot medication. Despite the advanced age of the subjects, significant adverse drug effects were uncommon.


Rehabilitation of a patient with lower-extremity quadriprostheses.

A case report is presented that demonstrates the successful rehabilitation of an 84-year-old woman who had undergone successive surgical procedures resulting in bilateral total hip replacement and bilateral prostheses for below-knee amputations, i.e., quadriprostheses. It is emphasized that age per se should not be a deterrent to energetic rehabilitation efforts.


Identification of normal aging and disease-related processes by health care professionals.

A 40-item quiz on aging was given to 46 health care professionals, before they participated in a workshop dealing with the care of the elderly patient. In the quiz, they were asked to identify physiologic and functional conditions either as normal aging processes or disease-related processes. In general the results indicated that disease processes were the easier entities to identify, and that the workshop experience enhanced this effect. Ability to identify functional disorders correctly did not differ significantly from the ability to identify physiologic symptoms correctly. Implications for the general health and the mental health of older adults are discussed.


Central-nervous-system stimulants: appraisal of use in geropsychiatric patients.

CNS stimulants such as methylphenidate and pentylenetetrazol are currently prescribed for the treatment of aged persons with symptoms of senility. A review of clinical studies conducted with these compounds indicates that firm evidence of efficacy is lacking. Because of the risks associated with high doses of such stimulants in the aged, it would seem that these compounds are of limited utility in geriatric psychiatry.


The vaginal flora after natural or surgical menopause.

A study was made of the cervical and upper vaginal flora in menopausal women, in an attempt to determine whether such women are predisposed to infections when undergoing gynecologic operations. The series comprised 72 women (age range, 44-80 years) classified as follows: a) 35 with a natural menopause, b) 18 with a surgical menopause induced by abdominal panhysterectomy, and c) 19 postmenopausal women after vaginal hysterectomy performed for genital prolapse. The vaginal flora of these menopausal women consisted predominantly of Gram-positive bacteria which, together with the Gram-negative bacteria, conformed to the normal pattern of microorganisms in the vagina. Such bacteria also are found in women of child-bearing age, but occasionally they can be pathogenic. Despite the inherent biohormonal changes of the memopause, expressed especially by the low estrogen level, 26.4 percent of the cultures in our study were sterile, even after major vaginal operations. Thus, the pattern of the vaginal flora, even though occasionally pathogen, should not be a contraindication to gynecologic surgical procedures in postmenopausal women. Even when vaginal cultures show the presence of these bacteria, it does not seem necessary to use prophylactic antibiotic and hormonal therapy routinely. Rather, it should be given selectively, depending upon the local state of the tissues and upon the postoperative course.


Age-related changes in endocrine and renal function in patients with essential hypertension.

Endocrine and renal functions were studied in 149 patients with essential hypertension by measuring plasma electrolytes, renin activity, creatinine and aldoserone, as well as the urinary excretion of creatinine and sodium chloride, before and during treatment for hypertension. Half of the patients responded to trichlormethiazide (thiazide-responsive group) but the other half did not (thiazide-unresponsive group). Systolic and diastolic blood pressures increased progressively uith age in the thiazide-unresponsive group, but were lower and did not progress with age in the thiazide-responsive group. There was no consistent difference in plasma renin activity between the thiazide-responsive and the thiazide-unresponsive groups. The fluctuation of plasma renin activity in response to an excess of sodium chloride or to thiazide treatment was reduced progressively with age. Creatinine clearance decreased and the blood urea nitrogen level increased with age. The age-related decrease of plasma renin activity is discussed on the light of the age-related impairment in the ability of the kidney to excrete sodium and water.


"Spontaneous" atheroembolic disease as a cause of renal failure in the elderly.

An 86-year-old man with previous normal renal function was hospitalized because of renal insufficiency. He had a long history of atherosclerotic heart disease, mild hypertension and pulmonary embolism, requiring anticoagulant therapy. In view of the normal-sized kidneys and absence of casts in the urinary sediment, a diagnosis of atheroembolic renal disease was made. The patient's renal function deteriorated, but he refused hemodialysis. Death occurred within a few weeks. At autopsy, severe aortic atherosclerosis was observed and atheroembolic renal disease was confirmed as the cause of renal failure. Occasionally, renal failure can be the sole manifestation of spontaneous atheroembolic disease. This possibility should be considered if the physician is called upon to establish the diagnosis when renal insufficiency develops in atherosclerotic patients.


The Life Satisfaction Index-Form A as applied to older adults: technical note on scoring patterns.

The value of standardized scales for determining life satisfaction among older adults is being questioned, but use of the scales continues. The Life Satisfaction Index-Form A (LSIA) in its many variations continues to be among the most widely used scales for this purpose. In a comparison of two scoring methods (36-point vs. 18-point) for the LSIA, the lack of a significant difference indicated that a 36-point scale is not necessary. Caution in the use and interpretation of the variances between the two scoring methods is suggested.


Mitral valve prolapse in the elderly.

This study included 40 patients over 60 years of age with echocardiographic findings of mitral valve prolapse (MVP). Most of these patients were unaware of any cardiac disorder until the time of echocardiography. In the majority, the clinical manifestations were benign, and the duration of symptoms variable. Congestive heart failure (CHF) was noted in 10 patients (25 percent) who were unaware of having any cardiac disorders until the onset of their symptoms. In 5 patients (4 with CHF and 1 with endocarditis), surgical replacement of the prolapsed mitral valve was necessary. Endocarditis was present in 4 patients (10 percent), none of whom had been instructed in the prophylactic use of antibiotics. The physician's awareness of mitral valve prolapse in the elderly patient is important, since the disorder may not be as benign in aged patients as in younger ones, and life-threatening complications may occur.


Behavior of dialifor, dimethoate, and methidathion in artificially fortified grape juice processed into wine.

Dialifor and methidathion were added to diluted "Zinfandel" grape concentrate at 25 ppm and dimethoate at 1.0 and 25 ppm prior to fermentation with Saccharomyces cerevisiae. The finished wine 56 days later contained 10% (2.5 ppm) of the dialifor, 46% (12 ppm) of the methidathion and 85% (21 and 0.98 ppm) of the dimethoate added to the grape must. Residues in wine stored at 24 degrees C dissipated by hydrolysis; half-lives in wine were 7 days for dialifor and methidathion and 30 days for dimethoate. Residues were unchanged in wine in frozen storage for one year. Analysis of seven commercial wines for dimethoate indicated less than 0.03 ppm dimethoate was present; identity could not be confirmed by thin-layer chromatography at this level.


Recovery studies of selenium using dry ashing procedure with ashing aid.

A previously reported dry ashing procedure for the decomposition of marine samples prior to arsenic determination is demonstrated to be equally applicable to the analysis of selenium. Quantitative recovery of selenium as inorganic or organic compounds in a variety of plants and animal tissues is demonstrated using 75Se tracer and X-ray fluorescence techniques. The dry ashing procedure is simpler than the official AOAC method, which uses a mixture of H2SO4, HNO3 and HC10(4).


Volatilization of 1,2-dibromo-3-chloropropane (DBCP) from soils.

The volatilization of DBCP from soils, as affected by the soil characteristics and application techniques, was studied in a laboratory experiment. The volatilization rate of DBCP applied in water was higher from sandy and silty loam soils than from clay soil. Water added after DBCP application acted as a soil cover, decreasing the volatilization rate. The results obtained with DBCP application in hexane to air-dry soils, indicate that adsorption could be an important factor in reducing the volatilization losses. Diffusion coefficients were calculated from the volatilization parameters, by using a simplified relationship between volatilization losses and diffusion through soil.


Effect of aldicarb on the growth, respiration and (14C) - glucose metabolism of Axotobacter chroococcum BEIJ.

Aldicarb [2-methyl-2(methyl thio) propionaldehyde-O-methyl carbamoyl oxime], which forms the active ingredient of a systemic oximic carbamate insecticide, at 2 ppm level did not affect the in vitro growth and respiration of Azotobacter chroococcum Beij, while concentrations at 5 ppm and 10 ppm levels were inhibitory. The insecticide treatment at 10 ppm level suppressed the assimilation of (14C) - glucose in the whole cells and in the cellular constitutents viz., cold - TCA soluble, hot TCA soluble fractions and insoluble residue. However, the 14C - incorporation in the alcohol soluble and alcohol-ether soluble fractions was enhanced indicating that aldicarb considerably altered the glucose metabolism of the organism.


A monitoring study of workers handling pesticides in warehouses and godowns.

Monitoring observations made on 60 operators involved in pesticide application work in godowns and warehouses and 60 matched control workers are reported. Occupational exposure history and medical history are noted. Biochemical investigations, plasma and RBC cholinesterase estimations are included along with medical examination of the workers. Workers were found to be mostly exposed to Celphos, DDVP, Malathion, Pyrethrum, etc, and the use of protective devices were very limited. Cases of significant reduction in plasma and RBC cholinesterase activity were found. Frequency of symptoms like dizziness, headache, lachrymation, burning sensation in eyes, nausea and anorexia, etc, were much more in the exposed workers. No cases of clinical poisoning attributable to occupational exposure to pesticides were reported by the workers.


Metabolism of 2-chloro-N-isopropylacetanilide (propachlor) in the rat.

Eleven urinary metabolites from [14C]propachlor were either identified or characterized by mass spectrometry. Those identified were 2-[S-(N-acetyl)cysteinyl]-N-isopropylacetanilide, 2-(methylsulfonyl)-acetanilide, 4'-hydroxy-2-(methylsulfonyl)-acetanilide, and 4'-hydroxyacetanilide. Those characterized were N-(1-hydroxyisopropyl)-2-(methylsulfonyl) acetanilide and its glucuronide, the glucuronides of 4'-hydroxy-N-isopropyl-2-(methylsulfonyl)acetanilide, N-(1-hydroxyisopropyl) aniline, 4'-hydroxy-2-(methylsulfonyl)acetanilide, and either N-(1-hydroxy-isopropyl) acetanilide or 2-hydroxy-N-isopropylacetanilide.


Metabolic fate of dichloromethyl-O,O-diphenyl phosphonate (I) and dichloromethyl-O,O-Di-(p-nitrophenyl) phosphonate (II) in/on rice plants.

Metabolic fate of two dichloromethyl diaryl phosphonates (32P labelled) in/on rice plants was investigated. The test compounds were found to be less persistent on the surface of rice leaves with half lives 7.4 and 6.7 days respectively. Main degradation product from both the phosphonates were dichloromethyl phosphonic acid with trace of dichloromethyl-O-aryl phosphonate as a transitory intermediate product.


Prenatal carbon monoxide and adult evoked potentials in rats.

Hooded rats prenatally exposed to mild carbon monoxide hypoxia were studied as adults. Flash evoked potentials were recorded from the visual cortex of unanesthetized exposed and control rats at four different flash intensities. The amplitude of bothe the P1-N1 and N1-P2 components on the flash evoked potential were significantly greater in CO-exposed female rats than in control females. The experiments thus demonstrate long term alterations in CNS function from exposure to relatively mild levels of CO.


Development of rat telencephalic neurons after prenatal X-irradiation.

Telencephalic neurons of rats, irradiated at day 15 of gestation with 125 R, develop synaptic connections on dendrites during maturation which appear to be normal spines in Golgi-stained light microscope preparations. At six weeks of postnatal age both control and irradiated rats have spiny dendritic processes on cortical pyramidal cells and caudate Golgi type II neurons. However, when the rats are 6 months old the irradiated rats have more neurons with beaded dendritic processes that lack spines or have only a few spines. These neurons resemble the neonatal neurons and are likely to be degenerating neurons. The apparently normal development of the neurons followed by degeneration in the irradiated rat has a parallel in previous reports of the delayed hyperactivity which develops in rats irradiated on the fifteenth gestational day.


Tissue distribution of inhaled mercury vapor in acatalasemic mice.

Substantial differences were observed in the pattern of tissue deposition in normal versus acatalasemic mice after inhalation of radioactive mercury vapor. Liver deposition was approximately double and lung deposition approximately one-half the corresponding deposition in normal animals. These results lend further support to the idea that the hydrogen-peroxide catalase peroxidative pathway plays a role in the metabolism of inhaled mercury vapor.


Early onset and topographical distribution of hypertrophied astrocytes in hippocampus of aging rats: a quantitative study.

Our results indicate that the density of astrocytes exhibiting hypertrophy in the hippocampus increases dramatically and progressively with age, being significantly elevated even in mid-life (13 month) animals. However, the total population of astrocytic cells (hypertrophied and nonhypertrophied) in the quantified region is not significantly elevated. Further, the relative distributions of both hypertrophied and total glial cells remained remarkably constant at the three ages measured. Reactive hypertrophy of astrocytes therefore appears to occur "in place" and migration of astrocytes does not appear to be a major factor in the hippocampus during aging. Of particular note was the finding that astrocyte hypertrophy is far more prominent in synaptic terminal fields than in myelinated fibers of the same system.


Nuclease digestion studies of mouse chromatin as a function of age.

Chromatin is organized into a repeating structure (nucleosome) made up of proteins and DNA. Micrococcal nuclease and DNAase I have been used to probe this structure in nuclear populations from three tissues (liver, brain and heart) of the inbred mouse strain C57BL at different ages. For those parameters examined in each tissue, chromatin contained essentially the same features of nucleosomal organization, regardless of the age of the mouse. Thus, the rate and extent of nuclease digestion, the size of the DNA repeat unit and nucleosome core are not significantly different as a function of age. However, the accessibility of internucleosomal DNA to micrococcal nuclease, as determined by measuring the DNA size distribution after nuclease cutting, may be partially limited in brain chromatin (but not liver or heart) of older animals. These results indicate that there are no gross, age-related changes in the conformational state or organization of chromatin in these tissues. The results do not exclude smaller alterations in chromatin which might occur with age and which the methodology employed might not be sensitive enough to detect.