Changing patterns of Staphylococcus aureus bacteremia.

Medical records of 134 patients with Staphylococcus aureus bacteremia at the Cincinnati General Hospital during 1975-1977 were reviewed. Bacteremia was community-acquired in 48 patients and hospital-acquired in 73 patients. In addition, 13 patients were on chronic hemodialysis. In 22 patients, bacteremia was associated with an infected intravenous catheter; all except one of these patients acquired the infection in the hospital. Thus 21 of 73 (29%) episodes of hospital-acquired S aureus bacteremia were associated with an infected intravenous catheter. Four of the 22 patients with intravenous catheter-associated bacteremia had endocarditis (18%). The overall incidence of endocarditis in this study was 16% (21 of 134 patients). This contrasted with the much higher incidence of endocarditis (64%) in Staphylococcal bacteremia reported from this same hospital in patients during 1940-1954. Possible reasons for this difference are discussed.


Foodborne outbreak of hepatitis A: clinical and laboratory features of acute and protracted illness.

During a 1974 foodborne outbreak of viral hepatitis type A among Navy recruits, we evaluated clinical and laboratory features prospectively in 130 affected persons. The ratio of anicteric to icteric persons identified during the outbreak was 1:3.5 but illness was relatively mild in this population of young adults. Infrequently reported in association with type A hepatitis, rash and arthralgias (but not arthritis) were reported by 14 and 10% of affected persons, respectively. Fourteen weeks after onset of acute illness, 8.5% of patients had persistently elevated aminotransferase activities and underwent percutaneous liver biopsy. Morphologic features included piecemeal necrosis, but clinical, biochemical, and histological evidence of disease resolved within five months to one year after the outbreak. Fecal shedding of hepatitis A virus began during the preicteric stage, did not persist beyond the second day of jaundice (even in patients with protracted illness), and was not detected in anicteric patients. Feces and serum obtained during the late incubation period, but not urine, were infectious in chimpanzees. Antibody to hepatitis A virus developed during convalescence, and serum anticomplementary activity was noted during acute illness. Failure of T-lymphocytes to bind sheep erythrocytes and form rosettes was observed, was found to be modulated in several cases by an intrinsic lymphocyte defect and in others by the presence in serum of an extrinsic immunoregulatory serum lipoprotein, "rosette inhibitory factor," which persisted in patients with slow resolution.


Acute effect of tobacco cigarette smoking on the platelet aggregate ratio.

The purpose of this study was to determine whether cigarette smoking acutely increased circulating platelet aggregates as detected by lowering of the platelet aggregate ratio. Eighteen (11 male and 7 female) volunteers ranging from 16 to 47 years of age rested during a 20-minute control period and smoked two unfiltered tobacco cigarettes during another 20-minute period. Platelet aggregate ratios (mean +/- SD) before and after the control period were 0.86 +/- 13 and 0.82 +/- 0.12 respectively (p greater than 0.05) and before and after smoking were 0.84 +/- 0.14 and 0.66 +/- 0.18 respectively (p less than 0.01). The mean plasma nonesterified fatty acid concentration was not significantly different before and after smoking suggesting that the decrease in platelet aggregate ratio was not mediated through elevation of the plasma nonesterified fatty acid concentration. Our results are consistent with the theory that platelet aggregates contribute to the increased incidence of myocardial infarction and sudden death from coronary artery disease observed among cigarette smokers.


Christ-Siemens-Touraine syndrome--a clinical and genetic analysis of a large Brazilian kindred: I. Affected females.

A total of 27 women of a Brazilian kindred are described as having one or more signs of the Christ-Siemens-Touraine syndrome. The history and physical examination were supplemented by four sweat tests and dermatolglyphic analysis. It is suggested that this syndrome has two forms -- a major form (in males) and a minor one (in females). Two signs verified in some of our patients (mosaic patchy distribution of body hair and radial deviation of distal phalanges of index fingers) seem to be here described for the first time. A review of the literature shows a corrected sex ratio between 1 M: 1.21 F and 1 M: 2.38 F among affecteds. Since the manifestation rate of the gene among carriers was estimated at about 0.70, the actual sex ratio is expected to be not lower than 1 M: 1.40 F. Contrary to a general opinion, affected females outnumber affected males.


The hypouricemic effect of o,p'-DDD.

o,p'-DDD, administered by mouth in doses of 1 to 7 grams daily for 5 to 42 days, was found to lower serum uric acid concentration in each of eight normouricemic patients (one with Cushing's disease and seven with metastatic cancer). The decrease ranged from 21 to 53% (average 39%) and the maximum effect was apparent in five to ten days. Urinary uric acid excretion showed no change, indicating that uric acid production was unaffected and that the hypouricemic effect resulted from an increase in the renal clearance of uric acid. The present findings introduce a new type of chemical compound to the group of known hypouricemic agents.


Christ-Siemens-Touraine syndrome--a clinical and genetic analysis of a large Brazilian kindred: III. Carrier detection.

Detection of carriers of the Christ-Siemens-Touraine syndrome on the basis of data of physical examination has been possible in about 60--70% of the cases reported in 44 papers, including a large Brazilian kindred studied by the authors. Partial data, however, showed detection values ranging from 42% to 84%.


The effects of chorion type on normal and abnormal developmental variation in monozygous twins.

To determine the effects, if any, of chorion type on normal and abnormal developmental variation in monozygous (MZ) twins, we tested the hypothesis that disparate environments that are related to chorion type have no effect on this variation. The parameters studied included congenital anomalies and dermatoglyphics (total ridge count and right-left asymmetry). With the exception of total ridge count, analyses of these data failed to reject the null hypothesis. Dichorionic MZ twins had a significantly greater within-pair variation than monochorionic MZ twins for total ridge count. In summary, then, these data could offer little support to prior speculation that monochorial placenta may present less favorable environments for feta development.


Presumed immune thrombocytopenia and carcinoma: report of three cases and review of the literature.

Three patients presenting in a one-year period with coexisting carcinoma and presumed immune thrombocytopenia are the subject of this report. Review of the literature disclosed a paucity of previous reports of this association. Possible pathogenic mechanisms resulting in this association are discussed. All three patients responded to corticosteroids in usual doses used in treatment of chronic idiopathic thrombocytopenic purpura. The association of carcinoma with immune thrombocytopenia may be more common than has been previously appreciated.


The prognostic features of biochemical investigations in tetanus.

Factors determining prognosis in tetanus have been based mainly on clinical grounds and mortality is high especially in the developing countries. The biochemical changes occurring in tetanus before any form of therapy or sedation, were examined to determine screening parameters for earlier institution of intensive care in high risk patients. The results obtained from a prospective study of 73 patients are presented. The blood sugar and serum transaminases correlated well with the severity of the disease. The serum glutamic oxalate transaminase and blood urea were significantly higher in fatal cases. These findings as well as the clinical criteria utilized in determining the severity of the disease in this study are useful in predicting the outcome of the disease. It is suggested that these simple investigations could serve as screening parameters for instituting early intensive care in tetanus.


Segregation of noisy Mendelian traits and the effect of age-dependence: a prolegomenon.

A discussion of the primordial confusion between the multiplicative Galtonian ("lognormal") trait and the imperfectly segregating Mendelian trait is laid out from a probabilistic standpoint. Several criteria used in comparing them (bimodality; bitangentiality; goodness of fit to the multinomialized form of the distribution; cumulants of the distributions) are reviewed and the inadequacy of their probabilistic properties discussed in some detail. The logical asymmetry of the normalized score ("Roberts" correction") and hence its invalidity as a criterion for distinguishing between the models is pointed out. The form of a mixture of two Gaussian distributions with fixed and equal variances but with differing age-dependent means ("the Platt model") is explored. The epistemological implications are exhibited. As a first step to restoring symmetry, a general model is proposed of which these and other models in wide use emerge as special cases. No attempt is made to deal here with the statistical aspects of the problem.


Neuraminidase in cultured fibroblasts and leucocytes of homozygotes and heterozygotes for the mucolipidosis II gene (I-cell disease).

The significance of neuraminidase deficiency reported to be the primary defect in mucolipidosis II has been evaluated by determination of this enzyme activity in cultured fibroblasts, culture medium, and leucocytes from homozygote and heterozygous carriers of the disease. A new and sensitive fluorometric assay of neuraminidase was used with sodium (4-methylumbeliferyl-alpha-D-N-acetylneuraminate) as substrate. We report: 1) nearly total deficiency of neuraminidase in mucolipidosis fibroblasts, 2) partial deficiency of this enzyme in leucocytes of one patient, 3) this decreased activity ceases to exist following Triton X-100 treatment, and 4) intermediary mean neuraminidase activity in fibroblasts and leucocytes from obligate heterozygotes. Although these results would be consistent with the suggestion that neuraminidase deficiency is the primary defect in this disease, evidence from the work of other authors suggests that the enzyme deficiency results from a secondary effect of the mucolipidosis II mutation.


Ampicillin resistant Haemophilus parainfluenzae endocarditis.

A case of Haemophilus parainfluenzae bacterial endocarditis is described. This is the first reported case of endocarditis caused by ampicillin resistant H parainfluenzae. Resistance was not mediated by a beta lactamase. Ampicillin therapy had not controlled the infection, but a four-week course of chloramphenicol was curative. Several general therapeutic points are discussed.


Prenatal diagnosis of congenital adrenal hyperplasia.

The accurate prenatal diagnosis of 21-beta-hydroxylase deficiency, based on amniotic fluid levels of 17-hydroxyprogesterone, is documented for a fetus 14 1/2 weeks old. In addition, family HLA genotyping data are consistent with the purported linkage between the HLA locus and the locus for 21-beta-hydroxylase.


4p trisomy syndrome: report of 4 additional cases and segregation analysis of 21 families with different translocations.

Thirty reports of partial 4p trisomy have been published. The manifestations and cytogenetic findings in four additional cases from two families are described in the present paper. Segregation analysis has been performed on the 21 families reported to date. The risk of having unbalanced offspring was the same in carrier mothers and carrier fathers. The risk of trisomic offspring was 14%. Among phenotypically normal progeny, normal karyotypes and balanced translocation states occurred with about equal frequency.


The SC phocomelia syndrome: report of two cases with cytogenetic abnormality.

We report two sibs with the SC phocomelia syndrome with typical facial appearance and bilateral absence or extreme hypoplasia of the fibula, radius, and thumb. One sib had bilateral humero-ulnar and femoro-tibial synostosis (absence of the elbow and knee joints). Application of the nosologic criteria of Herrmann and Opitz showed that there was no significant intrafamilial variation in phenotype. Chromosome analyses in both patients showed heterochromatic puffing and centromere separation involving many chromosomes, an observation that has previously been reported in patients with SC phocomelia and Roberts syndromes. More important, this finding will have significance in prenatal detection of a certain proportion of cases with these syndromes without resorting to the use of radiographic examinations.


The Perrault syndrome: autosomal recessive ovarian dysgenesis with facultative, non-sex-limited sensorineural deafness.

We report three sisters with ovarian dysgenesis; all three and two of their otherwise apparently normal brothers also had moderate to severe sensorineural deafness. Three similarly affected sibships are known, and the total of 14 affected patients includes three males with deafness without gonadal defect, one woman with ovarian dysgenesis without deafness, and ten women with ovarian dysgenesis and deafness. In two families parental consanguinity is known. We conclude that this condition, which we propose to designate the Perrault syndrome, is an uncommon autosomal recessive trait with obligatory ovarian dysgenesis in female homozygotes and facultative deafness in male and female homozygotes. Right bundle branch block and mental retardation may possibly be additional, less common pleiotrophic manifestations.


A family study of congenital inguinal hernia.

In fathers and mothers of 707 index patients with operated indirect congenital inguinal hernia (CIH) born in Budapest during the years 1962-1966 the frequency of CIH was two and five to six times higher, respectively, than in the general population. The rate of affected sibs was higher than that of parents but was greatly dependent on the sex of the index patient. Heritability estimates of CIH vary significantly in parents (0.35 +/- 0.12) and in sibs (0.78 +/- 0.14). In twins the heritability is 0.77. These data agree with the multifactorial threshold model involving dominance variance.


Ring chromosome 6 in a child with minimal abnormalities.

We describe a boy with a ring chromosome 6 and short stature, mild micrognathia, and bilateral transitional/simian creases. Five other patients with a ring 6 have been reported. The clinical and cytogenetic observations of all six patients are compared and discussed.


Genetics of acheiropodia ("the handless and footless families of Brazil"): XI. Pathologic aspects.

We report another case of acheiropodia, a rare autosomal recessive trait of distal limb deficiency, to date seen only in Brazil in persons of Portuguese ancestry. The patient's parent were first cousins; she had two younger affected sisters. She presented with signs of vascular insufficiency of the lower stumps, which after amputation were found to lack large vessels below the knee.


The "intra-abdominal version technique" for delivery of transverse lie by low-segment cesarean section.

Cesarean section is the delivery method of choice in all shoulder presentations of viable fetuses. The classic cesarean section is usually recommended when there is a transverse lie because of the potential technical difficulties associated with extraction of the fetus when a low-segment incision is used. This paper illustrates a technique that avoids the need of a classic cesarean section and permits the use of the more desirable low-segment cesarean section. The advantages of the procedure are discussed.


The effect of smoking and oral contraceptives on the urinary excretion of epinephrine and norepinephrine.

Eight smokers and seven nonsmokers between the ages of 20 and 38 years were studied. None of these patients was pregnant. Three smokers and two nonsmokers were not taking oral contraceptives, as contrasted by three nonsmokers and four smokers taking oral contraceptives. Results approached statistical significance for urinary norepinephrine (p = 0.15) and epinephrine (p = 0.07) when the groups were compared. The values for nonsmoking/noncontraception tended to be low but, unexpectedly, the values for smoking/contraception also were low. When the smoking subjects (six of seven) stopped there was a significant decline in norepinephrine (p = 0.02) and the epinephrine decline approached significance (p = 0.08). The study does not show any synergistic effect of oral contraceptives and smoking but demonstrates that the smoker can diminish stimulation of the adrenal gland (epinephrine) and sympathetic nervous system (norepinephrine) if she will stop smoking.


Probability of menopause with increasing duration of amenorrhea in middle-aged women.

The empirical percent probability that natural menopause has occurred after first presentation of amenorrhea of various durations in women greater than or equal to 45 years of age has been calculated using data from a cohort of subjects who prospectively recorded menstrual flow and related gynecologic events. The probability that menopause has occurred increases with the amenorrheal interval (duration), and for a given interval, the probability increases with age. After 180 days of amenorrhea, 45% to 72% of subjects were menopausal; after 360 days, 90%. These data may offer assistance in advising patients on the probability of menopause and the continuance of contraceptive practices, and in considering whether late genital bleeding after amenorrhea represents a physiologic or pathologic process.


Coagulation studies of patients taking low-dose heparin during and after major gynecologic surgery.

In February, 1975, a prospective, randomized study of 75 patients undergoing major gynecologic surgery was undertaken. Patients were randomly assigned to three groups regardless of diagnosis and surgery contemplated. Coagulation studies were performed preoperatively and postoperatively in a control group, a receiving 2,000 U heparin/12 hr subcutaneously, and a third group receiving 5,000 U/12 hr via the same route. There was a statistically significant increase noted in fibrin degradation products in the group treated with 5,000 U heparin/12 hr as compared to the control group. Excessive bleeding intraoperatively or postoperatively was not encountered.


Local versus general anesthesia: which is safer for performing suction curettage abortions?

The relative safety of suction curettage abortions performed with either local or general anesthesia has not been clearly established. To compare the safety of these two anesthetic techniques, we studied 36,430 women who received local anesthetics and 17,725 who received general anesthetics for this operation in the United States from 1971 through 1975. The aggregated major complication rates for the two groups were similar, but there were significant differences between local and general anesthesia for specific complications and treatments. Local anesthesia was associated with higher rates of febrile and convulsive morbidity; however, general anesthesia was associated with higher rates of hemorrhage, cervical injury, and uterine perforation. Both anesthetic techniques appear to be safe, with similar degrees of overall safety, although each is associated with a different spectrum of complications.


Rapid assessment of fetal pulmonary maturity.

The absorbance of amniotic fluid at 653 nm has been measured in 300 specimens and found to have a significant correlation with the L/S ratio. Then 118 patients were further evaluated for neonatal outcome. RDS was absent in 99% of patients with mature absorbance values. This determination has the advantage of rapid performance without specialized equipment or training and represents a significant contribution to the assessment of fetal pulmonary maturity.


Prenatal and intrapartum high-risk screening. II. Risk factors reassessed.

A method of identifying the high-risk pregnancy by a quantitative assessment of prenatal, intrapartum, and neonatal factors is presented. Calculating the probabilities of neonatal risk can be done with a hand-held calculator. The technique described provides a method of assessing the importance of perinatal variables and determining the effect of the process of health care on outcome.


Preinduction cervical priming with oral prostaglandin E2.

Seventy-three women, primigravidas and multigravidas, received 1.0 mg PGE2 tablets hourly for 5 doses the evening prior to scheduled induction of term labor to improve cervical ripeness. The over-all response to treatment depended upon the initial cervical score. Gastrointestinal side effects occurred infrequently and no complications to mother or fetus were observed. While the protocol used provoked an important in cervical favorability it is anticipated that a more prolonged PGE2 administration might achieve better results.


Hydronephrosis of pregnancy: ultrasonographic study and classification of asymptomatic women.

Ultrasonographic examination of the upper urinary tract in 109 asymptomatic pregnant women was performed to determine the degree of dilatation, the time of onset, and the range of "physiologic" changes detectable by this method. Classification is established and prevalence and degree of dilatation are categorized by trimesters. The onset of dilatation is seen earlier than previously reported and the degree of obstruction is quite variable for the asymptomatic patient. The right side predominates, as expected. The finding of mild dilatation in a symptomatic patient would prompt a search for causes other than obstruction.


Redistribution of cardiac output and oxygen delivery in the hypoxemic fetal lamb.

In hypoxia, fetal cardiac output and the product arterial O2 content x blood flow to the fetal heart and central nervous system (CNS) tend to remain constant. As a consequence the percentage of cardiac output directed to the heart and CNS increases hyperbolically in inverse relation to the oxygen content of the fetal ascending aorta, [O2]as. The fetal lamb maintains [O2]as approximately 0.45 mM (0.45 +/- 0.02 SEM) higher than the O2 content in the abdominal aorta, [O2]ab, over a wide range of oxygenation. When [O2]as decreases below the 2 mM level, the [O2]as--[O2]ab difference (delta O2) decreases also. A mathematical model of the fetal circulation shows that delta O2 is a function of the ratio oxygen consumption of fetal upper body/abdominal aorta blood flow (VU/FA). The behavior of delta O2 in hypoxia can be explained by assuming that the VU/FA ratio is maintained in moderate hypoxia and decreases in sever hypoxia.


Human fetal oxygenation following paracervical block.

To test the hypothesis that fetal heart rate (FHR) changes following paracervical block may be secondary to fetal hypoxia, human fetal oxygenation was measured continuously using a transcutaneous electrode. Following the block, each fetus demonstrated a decline in oxygen tension (tcPO2) at 5 minutes, which reached its lowest value at a mean of 11.5 minutes and remained at this level for an average of 3 minutes. Following the block, FHR variability increased at 5.2 minutes. reaching its maximal level by a mean of 7.5 minutes. By 11 minutes, a decrease in FHR variability was noted, which lasted for approximately 17 minutes. Decreased variability was not uniformly associated with low tcPO2. On some occasions, fetal tcPO2 declined even in the absence of increased uterine activity, which was noted at times following the block. The severity of the tcPO2 decline appears related to the analgesic effectiveness of the block.


External ocular toxicity of dipivalyl epinephrine.

Of 26 patients enrolled in a study designed to assess the usefulness of dipivalyl epinephrine 0.1%, administered topically at 12-hour intervals, for lowering intraocular pressure in patients with glaucoma and ocular hypertension, six patients (23.1%) developed adverse external ocular side effects severe enough to require that the drug be discontinued. Four of these six patients had a history of previous intolerance to epinephrine. The other two had successfully used epinephrine HCl 2% for more than two years before being treated with dipivalyl epinephrine and developed an adverse reaction after taking the drug 18 and 22 months, respectively. One patient with a history of epinephrine intolerance has successfully used dipivalyl epinephrine for 26 months to date. Our observations suggest that duration of exposure is an important factor in the development of sensitization to topically applied dipivalyl epinephrine.


The effects of timolol on cataract extraction and intraocular pressure.

We studied the effect of timolol on post-operative intraocular pressures (IOPs) in a control and experimental group of 30 eyes, each in patients who had uncomplicated intracapsular cataract extractions, most with iris clip lenses. Closure of the eye in each case was with three 6-0 silk sutures preplaced in a morticed incision. Six control eyes had IOP increases of 6 mm Hg or more within 24 hours of surgery. One patient treated with timolol had an IOP increase of 6 mm Hg or more. The differences in IOP between the control and experimental groups were statistically significant at the .01 level. The pressure lowering ability of timolol appears to be prophylactic as well as therapeutic. It is well suited for pseudophakic eyes as pressure reduction is not associated with pupillary alterations.


Calcium oxalate crystals in the aqueous.

We found octohedral crystals in the aqueous of a patient with phacolytic glaucoma. They were identified as calcium oxalate by their physical and chemical characteristics.


Recurrent macular pucker.

A 43-year-old man with a history of multiple anterior segment operations had a severe preretinal membrane affecting macular function. The bulk of this lesion was removed by using vitrectomy techniques, but a recurrence of preretinal tissue was observed a few months after this procedure. The recurrent epiretinal membrane was removed in a second operation.


Hemoglobin A1 and diabetic retinopathy.

The levels of the minor hemoglobin A1 components were measured in a consecutive series of 102 diabetic patients who were extensively studied for signs of diabetic retinopathy. We found a statistically significant relationship between metabolic control, as reflected by the hemoglobin A1 level, and the severity of diabetic retinopathy in patients with diabetes diagnosed before 30 years of age (P less than or equal to .001). We did not demonstrate a significant correlation between metabolic control and the severity of retinopathy in patients with diabetes diagnosed after the age of 30 years. We found significantly more severe retinopathy among patients with longer duration of the disease, in men, in whites, in diabetics diagnosted before 30 years of age who were treated with lower insulin doses, and in obses patients with the onset of diabetes after the age of 30 years.


Ischemic optic neuropathy as a possible early complication of vascular hypertension.

Eighteen patients with idiopathic optic neuropathy lacked symptoms and signs of cardiovascular and cerebrovascular disease, especially when compared to three groups of patients with sudden visual loss caused by retinal infarction, transient ischemia, and cerebral infarction. Many patients in the latter groups had hypertension, carotid bruits, heart disease, transient ischemic attack, and stroke. But among the patients with ischemic optic neuropathy, hypertension was the only evidence of cardiovascular disease, affecting 44% of the patients. We argue that, in many cases, ischemic optic neuropathy represents a direct and early complication of hypertension arterial disease affecting small arterioles supplying the anterior part of the optic nerve. The pathologic process may thus be similar or identical to lacunar infarction of the brain.


Staphylococcal ophthalmia neonatorum and the staphylococcal scalded skin syndrome.

A 3-week-old infant had neonatal ophthalmia neonatorum, treated in a routine manner which rapidly developed into an advanced case of staphylococcal scalded skin syndrome. The infant had sudden onset of widespread erythematous and tender areas of skin with subsequent exfoliation of large surface areas. We emphasize the recognition of this syndrome and the understanding that it may rapidly become a serious consequence of staphylococcal ophthalmia neonatorum. We stress the need for initial microbiologic studies and early antibiotic therapy for ophthalmia neonatorum.


Soft contact lenses from patients with giant papillary conjunctivitis.

We used scanning electron microscopy to study the surfaces of five coated soft contact lenses from subjects with giant papillary conjunctivitis. Findings were compared to the surfaces of five coated lenses from normal, asymptomatic wearers and five new, nerver-worn lenses. Lenses were from various manufacturers. All worn contact lenses differed strikingly from new, never-worn lenses. The anterior surface of worn lenses was covered with apparently adherent deposits. In only a few areas was the surface similar to new, never-worn lenses. Thick coatings on lenses from patients with giant papillary conjunctivitis and asymptomatic wearers were similar. High magnification of the coatings revealed a trabeculated morphology. Also seen was debris that resembled mucus-like material in both strand and particulate forms. On some lenses bacterial-shaped structures were scattered randomly over the surface. Smooth structures resembling cells were also seen. The posterior lens surface of all worn lenses was smoother than the anterior lens surface. The findings support our idea that the capacity to develop giant papillary conjunctivitis is influenced by individual differences more than by differences in lens deposits.


Inverted papilloma of the conjunctiva.

We encountered inverted papilloma of the conjunctiva in three cases. To the best of our knowledge, this tumor, which typically involves the nose, paranasal sinuses, and lacrimal sac, has not been described previously in the conjunctiva. Two of the tumors occurred as purely inverted lesions of the inner canthal region )caruncle and plica) and the third as a mixed inverted-exophytic papilloma over the tarsus. Melanotic pigmentation in one of the lesions was clinically confused with malignant melanoma. Because of the high incidence of recurrence of these tumors in the sinuses and lacrimal sac, and their unknown biologic behavior in the conjunctiva, inverted papillomas should be removed completely and the patients carefully observed.


Consequences of eyelid squeezing on intraocular pressure.

We investigated the effect of a forcible eyelid squeeze (two-second squeeze and two-second rest) over one minute, on intraocular pressure in volunteer groups of normal volunteers, ocular hypertensive and glaucoma patients, and those with a family history of glaucoma. The normal volunteers fell into two groups: responders and nonresonders, with the responders showing about a 2-mm Hg decrease and the nonresponders a small increase in intraocular pressure. It was possible to arrange the groups into an order dependent upon the change in intraocular pressure induced by eyelid squeezing; normal responders (-1.98 mm Hg), family history of glaucoma (-0.48 mm Hg), ocular hypertensive patients (-0.07 mm Hg), normal nonresponders (+ 0.04 mm Hg) and glaucoma patients (taking medication) (+ 0.25 mm Hg). Correlation of disease entity with other ocular factors such as intraocular pressure and total outflow facility was poor.


Experimental perfusions through the anterior and vitreous chambers with possible relationships to malignant glaucoma.

Enucleated eyes were perfused alternately via the anterior and vitreous chambers. At low intraocular pressure (IOP), vitreous humor presented considerable resistance to forward flow of perfusion fluid in calf eyes, but not in human eyes. In human eyes when the perfusion pressure was increased to 60 mm Hg, the resistance to flow forward from the vitreous body increased, but became practically nil again when the IOP was decreased. At high pressure the volume of the vitreous body apparently increases and the anterior hyaloid membrane probably presses against the ciliary body, reducing the area of hyaloid membrane through which fluid can flow. Whether increased perfusion pressure can in some other manner change the permeability of human vitreous to resemble that of the calf remains unanswered. Our results suggest that factors other than, or in addition to, simple diversion of aqeous humor must be important in malignant glaucoma.


A 20-gauge illumination and irrigation instrument for pars plana vitrectomy.

We developed a 20-gauge combination illumination-irrigation probe for use in pars plana vitrectomy. This instrument makes the vitrectomy procedure less traumatic and technically easier.


Combined trabeculectomy and cataract extraction.

We performed combined trabeculectomy-cataract extraction in 37 eyes of 29 patients. Average follow-up was 23.7 months. Thirty-three (89.2%) of the 37 eyes were controlled with much improvement postoperatively. A total of 35 eyes (94.6%) were controlled postoperatively; 22 eyes (59.5%) required no medications postoperatively. No greater incidence of complications with the combined procedure from that expected with cataract extraction alone was evident, except for four flat or shallow chambers and four hyphemas, none of which appeared to have an adverse effect on the final outcome of the surgery. We believe that the combined trabeculectomy-cataract extraction is a valid and safe procedure, if not the procedure of choice, in our hands, for the patient with coexisting cataract and glaucoma, and the advantages of the greater pressure control with the single procedure outweight the small increase in the risks of the surgery.


Broken nylon iris fixation sutures.

Broken nylon iris sutures, used to fixate the Worst suture lens, occurred in 41 of a series of 215 eyes, a remarkably high frequency. The estimated average time to break was 27.8 months. Over three fourths of the borken sutures were discovered incidentally on a return visit. Complications related to the broken suture occurred in 21 eyes. The characteristic complication was corneal epithelial edema caused by intermittent touch of the endothelium by the broken suture; spontaneous lens dislocation was infrequent. Light and scanning electron microscopy revealed that biodegradation caused the suture break. Broken iris  sutures can be avoided by fixation of the lens with a nonbiodegradable suture.


Lens implantation and diabetes mellitus.

In a series of 1,160 implant cases, 82 patients were diabetic. In this subgroup, lenses were implanted in 87 eyes, and a visual acuity of 6/12 (20/40) or better was obtained in 77 (88.6%) of the patients, which compared well with the nondiabetic control group of 1,078 cases. Only patients with normal fundi or minimal background retinopathy were operated on, and the visual results obtained were independent of the diabetic medical management.


Speckle movement in laser refraction. I. Theory.

Slowly rotating, cylindrical, diffusing drums have been widely used in laser refraction. A simple geometrical evaluation of the optical path lengths involved is used to derive expressions for the position of the plane of stationarity and the apparent speed of speckle motion as a function of the characteristics of the illuminating wavefront, the drum, the refraction of the observer, and other system parameters. With apparatus of known characteristics, determination of the apparent speckle velocity allows calculation of the ametropia of the observer.


The effect of cycloplegia on the determination of refractive error by the Ophthalmetron.

The Ophthalmetron was used to measure the refractive error of 10 male optometry students. Although there was a high incidence of invalid readings, more repeatable results were obtained with use of a cycloplegic. Measurements made under cycloplegia revealed 0.41 D more hyperopia but no differences in astigmatism as compared to the noncycloplegic refraction. Instrument myopia was shown not to be a factor.


The position of the corneal apex in the normal eye.

The position of the apex of the cornea was found for 1000 "normal" eyes (500 right; 500 left) from photoelectronic keratoscopic analysis. The corneal apex was located on the vertical meridian in 21.3% of the eyes, temporally in 62.4%, and nasally in 16.3%. Although a temporally biased location for the corneal apex was demonstrated, 62.2% of the eyes had the apex within 0.5 mm of the visual axis. The implications of these findings in contact lens fitting are discussed.


Marcus Gunn pupil in a possible case of unilateral retinitis pigmentosa.

A possible case of unilateral retinitis pigmentosa (RP) is reviewed. The electrodiagnostic and clinical findings are discussed, with perspective given to alternative diagnoses. A review of the literature is included to show the controversy which clouds a positive diagnosis of unilateral RP. A co-existing Marcus Gunn pupil is defined and discussed in relation to unilateral RP-like processes.


Identifying and teaching affective skills in optometric education.

Skills of interviewing, counseling, and patient management have been identified as vital parts of the ASCO curriculum model. This paper reviews the current status of the affective components of the optometric curriculum and describes a course which has as its goal the teaching or affective skills to optometry students.


Normative and clinical data with a new type of dark adaptometer.

Dark adaptation has been measured with a new type of dark adaptometer in a group of 25 normal subjects, and in a group of 10 patients suffering from a variety of retinal pathologies. The results indicate that this instrument is capable of distinguishing between normal and pathological dark adaptation on the basis of data obtained in two clinical samples.


A laser retinoscope.

A retinoscope that uses a He-Ne laser as its light source has been designed. By this means it is possible to improve the performance of the conventional retinoscope. In particular the contrast of the fundus reflex has been enhanced and the retinoscope can be used at a greater working distance than usual. By using a polarized laser the specular reflections from the eye are completely suppressed. The retinoscope lends itself to refractions under normal room illumination. Patients find the light from the laser retinoscope less bothersome than that of the usual tungsten filament lamp. Advantages and disadvantages of the unit are discussed.


Sagittal depth considerations in the selection of the base curve radius of a soft contact lens.

Examination of the relationship between the sagittal depth of the cornea and the sagittal depth of an optimally fitting soft contact lens reveals that base curves are not always well chosen. The author reports a new system for selecting the number, range, and distribution of base curve radii such that the range of saggital depths clinically encountered is covered evenly. The saggital increment between adjacent base curves is then 0.1 mm.


Corneal response to thick and thin hydrophilic lenses.

Thick and thin hydrophilic lenses with otherwise similar parameters were worn by patients for a period of 6 months. The thicker lenses produced greater changes in corneal sensitivity and thickness during the course of adaptation and wear than did the thinner lenses. Chronic edema levels of 3--4% were noted with the thick lenses. Changes in corneal power for each lens group were not significant. Thin hydrophilic lenses seemed to produce less upset of normal corneal physiology over the course of the 6-month wearing period.


Panoramic viewing, visual acuity of the deviating eye, and anomalous retinal correspondence in the intermittent exotrope of the divergence excess type.

Monocular visual acuities in a binocular field of view, field of view under binocular conditions, and retinal correspondence were investigated in five intermittent exotropes of the divergence excess type. Results indicated that all five intermittent exotropes demonstrated (1) normal visual acuity in the deviating eye without suppressing the fixating eye, (2) a lateral extension of the temporal field of view (panoramic viewing), (3) anomalous retinal correspondence.


Hydrogel lens power and oxygen transmissibility.

Measurements of oxygen transmissibility are reported for hydrogel lenses of different power. Center thickness is related to oxygen transmissibility, and it is shown that the relation is different for lenses of high dioptric power compared with lenses of low power. For high plus lenses, the oxygen transmissibility is higher than would be expected from a simple consideration of center thickness and the oxygen permeability of the contact lens material. For high minus lenses, the oxygen transmissibility is less than would be expected. Clinically, this means that power as well as center thickness must be taken into account when estimating the oxygen transmissibility of high power lenses.


Bilateral keratoconus posticus circumscriptus: a case report.

The characteristics, clinical appearance, and frequency of the rare corneal condition, keratoconus posticus circumscriptus, are discussed. A bilateral case of this condition, examined by use of techniques not previously employed, is described.


Epicapsular stars with visual loss.

The presence of epicapsular stars (congenital epicapsular pigmentation) is a common occurrence, but it can become clinically significant when vision is impaired. A case history reporting such a condition is presented.


Field "expansion" by use of binocular full-field reversed 1.3X telescopic spectacles: a case report.

Full-field reversed 1.3X telescopes were used in the treatment of a 63-year-old male retinitis pigmentosa (R.P.) patient with a 5 degree central field. The patient was highly motivated to "expand" his visual field. He was trained intensively with 1.3X, 1.7X, and 2,2X reversed telescopes prior to prescribing. Evaluations by the Orientation and Mobility staff indicated significant improvements in his functioning with the devices. The reversed telescopes expanded his field to approximately 14 degrees. Patient has been reevaluated after using the aid at home and remains enthusiastic about his successful use of the aid. This case is notable in that binocular, low-power, full-field, reversed telescopes are being used successfully for mobility, eating, and other tasks.


Evaluation of the binocularity of 147 unilateral and bilateral pseudophakic patients.

Tests of binocular functions were performed on a group of 147 patients with unilaterally or bilaterally implanted intraocular lenses. The quality of the binocular vision achieved was significantly better than that of unilateral aphakic patients wearing contact lenses. Compared to the normal population, the stereoscopic threshold in the pseudophakic population was found to be slightly poorer. Visual acuity, anisometropia, lens fixation, and vertical deviation were analyzed in relation to stereopsis.


Efficacy of compression gloves in rheumatoid arthritis.

Twenty-three patients with rheumatoid arthritis whose disease had become stabilized while receiving non-steroidal, anti-inflammatory drugs and/or gold salt injections entered an 8 week crossover study in which the effect of a compression glove worn during sleep was compared to a loosely fitting glove made of the same material. Improvement in hand symptoms was greater with the compression glove than with the control glove as regards morning stiffness, pain, night time throbbing, numbness or heaviness and a subjective assessment of swelling (p = 0.01). In addition, swelling of the proximal interphalangeal joints was slightly reduced (p = 0.05). These data suggest that the night time use of compression gloves in patients with rheumatoid arthritis can improve hand symptoms and exert a mild, transiently beneficial effect upon the degree of hand swelling.


Analysis of dorsal pitting in the os publis in an extensive sample of modern American females.

Pubic bones from 486 modern American females between the ages of 13 and 99 were studied in an attempt to explore the relationship between the degree of dorsal pitting and the following variables: (1) number of full term pregnancies, (2) inteval since last pregnancy, (3) age of decedent.A statistical association was found between the number of full term pregnancies and the degree of dorsal pitting. However, the correlation is not strong; 17 females reported as being nulliparous have "medium to large" dorsal changes whereas 22 females having from one to five full term pregnancies have an absence of dorsal changes. Females who had their last child 15 or more years prior to death are more apt to have "medium to large" dorsal changes than are females who have more recently given birth. This effect appears to be independent of the number of full term pregnancies, but is probably related to age. When the data are analyzed by multiple regression analaysis, it is found that age and number of pregnancies are most important in predicting the degree of pitting and the effect of the interval on pitting is not significant. Age is found to be an important variable independent of the number of full term pregnancies. In nulliparas, an absence of dorsal pitting is far more frequently found in females younger than 30 than in those over 30.


Parturition and pelvic changes.

A detailed analysis of the female bony pelvis in relation to parity status was made. A total of 198 complete pelves were inspected for five features considered to be associated with pregnancy and parturition. During final analysis two features were eliminated. Three remaining features - dorsal pubic pitting, pre-auricular grooves, and grooves located at the site of interosseous ligament insertion were found to be significantly related to partirution. Other findings of interest were: (1) pits and grooves acquired through pregnancy and parturition appear to become obliterated in old age, (2) the preauricular groove is the most sensitive indicator of pregnancy and parturition, (3) moderate-large pitting in the dorsal pubic region rarely occurs in nulliparous females, and (4) it is doubtful that more precise statements than "no children" and "one or more children" can be made on the basis of skeletal remains alone.


Insulin antagonistic effects of epinephrine and glucagon in the dog.

The effect of glucagon and/or epinephrine on the response to physiologic insulin infusion was evaluated in dogs. Insulin alone produced a transient fall (50%) in glucose output, a threefold rise in glucose clearance, and a decline in plasma glucose, which then stabilized (40--45 mg/dl) afer 1 h. Glucagon infusion prevented the fall in glucose output, but had no effect on insulin-induced elevations in glucose clearance. The fall in plasma glucose was delayed (20 min), but late hypoglycemia was unaltered. Epinephrine infusion blocked the fall in glucose output as well as the insulin-induced rise in glucose clearance and uptake. Thus, while epinephrine and glucagon were equally effective in preventing the fall in glucose output induced by insulin, epinephrine was more effective in preventing insulin-induced hypoglycemia by virtue of its direct inhibitory action on insulin-stimulated glucose utilization. Simultaneous addition of glucagon and epinephrine increased glucose output twofold, suppressed glucose clearance, and caused a 15--30 mg/dl increase in plasma glucose despite ongoing hyperinsulinemia. Our data thus indicate that synergistic hormone interactions may play a role in the counterregulation of insulin hypoglycemia.


Glucocorticoid and estrogen regulation of corticosteroid-binding globulin production by rat liver.

We have recently demonstrated that rat liver can synthesize and secrete corticosteroid-binding globulin (CBG). The present study extends these observations and examines the hormonal regulation of hepatic CBG production. Male rats were pretreated by adrenalectomy and/or glucocorticoid or estrogen administration and the rate of CBG production was measured in vitro. The production rates were assessed by the generation of specific corticosterone binding sites in both a liver-slice preparation and in an isolated perfused liver. The two techniques showed qualitatively similar results. Adrenalectomy enhanced and glucorticoid administration inhibited the rate of CBG production and secretion. Pretreatment of male rats with estradiol stimulated the rate of CBG production. The production rates were 20- to 40-fold higher in the perfused liver demonstrating its superiority over the liver-slice system. The livers from intact rats secreted CBG binding sites at a rate of approximately 18 pmol/g liver per hours, generating an estimated 20% of the total CBG content of a rat each day. The possible clinical implications of the therapeutic use of glucocorticoids that bind to CBG, yet inhibit CBG production, are discussed.


Effects of bilirubin on fat cell metabolism and lipolysis.

Bilirubin (0.45 mM) inhibited lipolysis and stimulated [1-14C]glucose oxidation by rat fat cells in the presence of an equimolar concentration of bovine serum albumin. Bilirubin was an insulinlike agent with respect to inhibition of lipolysis and stimulation of glucose oxidation. There was a marked inhibition of adenylate cyclase activity of fat cell ghosts by 0.001--0.1 mM bilirubin in the absence of albumin, which was largely reversed by the addition of albumin. Although both bilirubin and free fatty acids bind to albumin, the primary binding sites appear to be separate. The effects of bilirubin at a molar ratio to albumin of 2 or less were not influenced by free fatty acid-to-albumin ratios up to 3. Triglyceride lipase activity of partially purified rat fat cell homogenates was inhibited by bilirubin in the presence of an equimolar concentration of bovine albumin. These data indicate that the antilipolytic action of bilirubin is probably due to direct inhibition of triglyceride lipase through a mechanism that does not involve competition with free fatty acids for binding to albumin.


Hepatic uptake of insulin in man.

The hepatic uptake of unlabeled insulin (5--50 mU/kg) was determined in 45 nondiabetic patients without hepatic disease. Thirty patients were studied at normoglycemia and 15 at moderate steady hyperglycemia, induced by intraportal infusion of 80 or 200 mg glucose per h and per kg. The first pass fractional hepatic uptake of insulin (FH) was estimated by comparing the results after a portal and a peripheral infusion of unlabeled insulin in each patient. It varied negatively with the amount of insulin given, decreasing about 50% after a tenfold increase in dose. FH was markedly smaller during steady hyperglycemia than at normoglycemia, regardless of insulin dose. For low doses (5--10 mU/kg), giving insulin concentrations within the physiological range, FH was 0.43 (5 mU/kg) and 0.40 (10 mU/kg) at normoglycemia and 0.16 (10 mU/kg) at hyperglycemia. FH did not vary with the fasting or the glucose-stimulated, endogenous insulin levels recorded before insulin infusion. It is suggested that glucose is more important than insulin in modulating the fractional hepatic uptake of insulin.


Influence of bile salts on hepatic transport of dibromosulphthalein.

The influence of bile salts on hepatic transport of the organic anion dibromosulphthalein (DBSP) was investigated in rats. Bile salts influence the hepatic uptake, intracellular binding, and biliary excretion of DBSP. The overall effect depends on the administered dose of bile salts and DBSP. High doses of bile salts inhibited hepatic uptake of DBSP, whereas low doses of bile salts stimulated bile flow and simultaneously increased maximal biliary excretion of DBSP. The uncharged nonbile salt choleretic ouabain also stimulated biliary DBSP excretion. In contrast, the anionic nonbile salt choleretics, ethacrynic acid and theophylline, did not stimulate biliary excretion of DBSP. Because DBSP inhibited biliary excretion of ethacrynic acid and its metabolites, the lack of a stimulatory effect of ethacrynic acid choleresis might be explained by concomitant inhibition of biliary excretion of DBSP, masking the stimulatory effect of ethacrynic acid. Biliary transport maximum of DBSP was highly correlated with bile flow. The biliary clearance (Vmax/Km) was only moderately changed by bile salt administration, whereas the increase in the maximal biliary excretion rate was more pronounced, implying that the apparent Km for biliary excretion of DBSP was also increased by the bile salts. It is inferred that the stimulation of net biliary excretion of DBSP by bile salts may be due to a diminished transport from bile into the hepatocytes as the consequence of the decreased biliary concentration caused by the choleresis.


Vasoactive intestinal polypeptide in vagally mediated pancreatic secretion of fluid and HCO3.

The role of nerves that liberate vasoactive intestinal polypeptide (VIP) in the porcine pancrease as mediators of the atropine-resistant action of the vagus on flow and bicarbonate (HCO3) secretion was examined. Efferent electrical stimulation of the vagus in atropinized pigs produced a profuse flow of pancreatic juice with high HCO3 content concomitantly with a significant increase in pancreatic VIP output from 13 to 113 fmol/min. Intravenous administration of somatostatin (SRIF) during continuous electrical vagal stimulation caused a parallel suppression of the VIP release and the pancreatic fluid and HCO3 secretion to prestimulatory values. The SRIF-induced reduction in fluid and HCO3 secretion seemed to be mediated via an inhibition of the VIP release rather than through a direct effect on the exocrine cells, inasmuch as SRIF did not influence the VIP-provoked exocrine response from the in vitro isolated perfused porcine pancreas. The results support the view that VIP is transmitter in the vagally induced atropine-resistant water and HCO3 secretion from the porcine pancreas.


Intestinal capillary blood flow during metabolic hyperemia.

It has been postulated that local circulatory control mechanisms regulate the O2 flux to parenchymal cells by two vascular mechanisms: changes in blood flow that minimize capillary PO2 variations and changes in the density of the perfused capillary bed through which O2 extraction is regulated. To test this prediction, isolated loops of canine jejenum and ileum were perfused at either constant blood flow or constant pressure, and intraluminal glucose was used to increase metabolic rate. In the constant-flow series, glucose increased O2 extraction, O2 uptake, and rubidium extraction. Resistance fell when the metabolic rate was elevated. In the constant-pressure series, glucose increased blood flow, O2 extraction, O2 uptake, and capillary filtration coefficients. These results show that vascular resistance falls and that capillary density increases following an increase in oxygen demand. Thus, the glucose-stimulated gut loop seems to be a valid model of metabolic hyperemia, and its behavior would be difficult to reconcile with a purely myogenic theory of intestinal blood flow autoregulation.


Pancreatic and gastric release of somatostatinlike immunoreactivity during intestinal phase of a meal.

The present study was designed to examine pancreatic and gastric D-cell function during the intestinal phase of a liver meal. The intraduodenal instillation of a 20% liver meal (5 ml/min) elicited a significant rise in the plasma levels of somatostatinlike immunoreactivity (SLI) in the pancreatic vein and inferior vena cava, together with the rise in glucagon and insulin levels. The rise in pancreatic vein SLI was not reduced after truncal vagotomy or during atropine infusion. In the stomach, the intestinal liver meal elicited a significant rise in antral but not fundic vein SLI levels. The rise in antral vein SLI was augmented after truncal vagotomy and abolished during atropine infusion, as was the rise in inferior vena caval SLI. In contrast to the protein meal, intravenous infusion of an amino acid mixture elicited a rise in pancreatic vein SLI but not antral or fundic vein SLI. It is concluded that during the intestinal phase of a protein meal, pancreatic and antral but not fundic SLI release is stimulated. The effects of truncal vagotomy and atropine infusion on these responses suggest a close interaction between the vagus and muscarinic cholinergic mechanisms and the D cells of the stomach and pancreas.


Pathways of cycloleucine transport in killifish small intestine.

By using blocking concentrations of competitors, i.e., concentrations of other neutral amino acids that cause maximal inhibition, cycloleucine transport into slices or everted sacs of killifish (fundulus heteroclitus) small intestine could be partitioned into three pathways. One is apparently not mediated, a second is inhibited by all neutral amino acids tested (component 1), and a third, is inhibited by alpha-aminocarboxylic acids (component 2), but not by beta-alanine or taurine. Both mediated pathways were Na dependent, and each yielded a linear double reciprocal plot of initial slice uptake vs. cycloleucine concentration. Apparent Kt and Vmax values for component 1 were 0.03 mM and 33 pmol/mg tissue per 3 min, respectively; corresponding values for component 2 were 0.12 mM and 28 pmol/mg tissue per 3 min. Additional experiments with an intestinal brush border membrane vesicle preparation indicate that these mediated components reflect true differences in carrier specificity rather than the differential effects of inhibitors on metabolism or on the Na gradient that drives cycloleucine transport.


Bradykinin-induced renal hemodynamic alterations: renin and prostaglandin relationships.

The present studies examined the role of the renin-angiotensin system as a modifier of the renal vasomotor response to bradykinin. Renal arterial bradykinin infusion (80 ng.kg-1.min-1) initially resulted in increased renal blood flow (RBF). The secretory rates of renin and prostaglandins increased after 60 min. With continued bradykinin administration (120 min) RBF and prostaglandin secretory rates returned toward control values, although renin secretory rate remained elevated (P less than 0.02). After prostaglandin synthetase inhibition, RBF decreased and bradykinin administration returned RBF to control values. Prostaglandin secretory rates decreased after meclofenamate (P less than 0.005). Continued bradykinin infusion resulted in a return of the renin secretory rate to control values. The administration of bradykinin after competitive inhibition of angiotensin II resulted in a sustained increase in renal blood flow. These results suggest that the initial bradykinin-induced renal hyperemia is only partially dependent on enhanced prostaglandin release, the increase in renin secretion by bradykinin infusion after prostaglandin synthetase inhibition is consistent with a bradykinin and renin interaction, and the lack of a sustained hyperemia after bradykinin is related to increased renin-angiotensin system activity.


Volume expansion-induced alterations in proximal tubule chloride gradient in the rat.

To elucidate the mechanisms by which acute volume expansion (AVE) induces a decrease in proximal tubule transepithelial chloride gradient, male Sprague-Dawley rats were studied before and after AVE with Ringer lactate. In group 1, after AVE equivalent to 10% body wt, there were decreases in both tubule fluid to plasma inulin ratio ((TF/P)In) (from 2.28 +/- 0.10 to 1.57 +/- 0.05) and tubule fluid to ultrafiltrate chloride ratio ((TF/UF)Cl) (from 1.25 +/- 0.02 to 1.18 +/- 0.02). Group 2 was studied during carbonic anhydrase inhibition (CAI) produced by benzolamide before and during superimposed AVE (20% body wr). Both (TF/P)In (from 1.91 +/- 0.10 to 1.41 +/- 0.08) and (TF/UF)Cl (from 1.07 +/- 0.02 to 1.01 +/- 0.01) decreased. Group 3 was studied during maintained AVE (15% body wt) as a control for group 4, in which CAI was superimposed on maintained AVE. In group 3, (TF/P)In and (TF/UF)Cl did not change, but in group 4 CAI was associated with a decrease in (TF/P)In (from 1.55 +/- 0.05 to 1.21 +/- 0.05) and in (TF/UF)Cl (from 1.16 +/- 0.01 to 1.04 +/- 0.07). These data suggest that in the superficial proximal convoluted tubule of the rat, AVE-induced alterations in transepithelial chloride gradient are dependent on a mechanism(s) other than changes in carbonic anhydrase-mediated bicarbonate reabsorption.


Renal autoregulation of blood flow and filtration rate in the rabbit.

Electromagnetic flow techniques and inulin clearance were used to determine the autoregulatory capabilities of the rabbit kidney in vivo. Renal blood flow was measured in 13 animals over a renal perfusion pressure range of 40-110 mmHg. Normal renal blood flow averaged 3.2 +/- 0.3 ml.min-1.g kidney-1 and was efficiently autoregulated above a renal artery pressure of 75 mmHg. For every 10 mmHg renal pressure change above 75 mmHg renal blood flow changed only 0.96%. Renal perfusion pressure was reduced from 102 +/- 3 to 74 +/- 2 mmHg in six animals. Over this pressure range glomerular filtration rate was not significantly decreased and averaged 4.2 +/- 0.5 ml/min at high pressure compared to 4.0 +/- 0.5 ml/min at low perfusion pressure. Results show that the rabbit kidney autoregulates renal blood flow and glomerular filtration rate efficiently above 75 mmHg. This range of autoregulation compares well with the autoregulatory range of the dog. The results also show that in the autoregulatory range the rabbit and the rat appear to autoregulate with equal efficiency but that the rabbit kidney begins to autoregulate at a low perfusion pressure than the average of approximately 100 mmHg usually found in the rat.


Changes in the diastolic pressure-diameter relation after ventricular function curves.

Systolic performance depends on end-diastolic muscle fiber length, contractility, and afterload. Ventricular function curves are constructed using end-diastolic pressure instead of end-diastolic dimensions, on the assumption that end-diastolic pressure and end-diastolic dimensions (reflecting muscle fiber length) have a constant relation. That assumption has been rejected. Theorectically, ventricular function curves should change with changes in the diastolic pressure-dimension relation as well as with contractility or afterload. We measured pressures and dimensions in ventricles of six open-chest dogs before and after opening the pericardium to alter diastolic pressure-dimension relations with afterload constant. When an indicator of systolic performance (developed pressure times diameter change during systole) was plotted against end-diastolic pressure, data obtained with the pericardium closed and open resulted in two distinct curves, suggesting an increase in contractility with the pericardium open. However, when systolic performance was plotted against end-diastolic diameter, data obtained with the pericardiumclosed and open fell along one curve, indicating no change in contractility. Therefore, changes in the diastolic pressure-dimension relation to shift conventional ventricular function curves.


Interaction between the baroreceptor and Bezold-Jarisch reflexes.

The interaction between the carotid baroreflex and Bezold-Jarisch (BJ) reflex (intravenously administered veratridine) was studied in anesthetized rabbits after aortic nerve section. The carotid sinuses were vascularly isolated to regulate the intrasinus pressure (ISP). The extent of BJ reflex bradycardia and hypotension was progressively diminished as the ISP was elevated stepwise. When the carotid baroreflex was not operative by holding the ISP constant at control, the BJ reflex changes in heart rate (HR) and systemic arterial pressure (SAP) were not significantly different from those induced at the normal condition. Thus the calculated baroreflex static loop gain was greatly decreased during the BJ reflex. However, sinus denervation, analogous to keeping ISP below 50 mmHg, significantly enhanced the BJ reflex effects. A steady-state infusion of veratridine remarkably reduced the slope of the baroreflex function ISP-SAP and ISP-HR curves. The results indicate that the BJ reflex effects are affected by the prevailing arterial baroreceptor input, varying inversely with the ISP level. An attenuation in the baroreflex sinsitivity, in terms of the loop gain or slope of the transfer function curve, was observed during the BJ reflex. The presence of tonic cardiovascular inhibitions exerted by the arterial baroreceptors tends to reduce the BJ reflex bradycardia and hypotension, but the baroreceptors do not function adequately in buffering the cardiovascular inhibition produced by the cardiogenic reflex.


Interaction between carotid sinus baroreceptor and aortic nerve pressor reflexes in the dog.

In dogs anesthetized with morphine-chloralose, strong, low-frequency (2 Hz) electrical stimulation of the aortic nerve (AN) causes pressure in the perfused hindlimbs to rise. This pressor response is followed by a large depressor phase upon cessation of stimulation. Simultaneous stimulation of the ipsilateral carotid sinus nerve (CSN) with intermittent trains of stimuli enhanced the AN pressor response by 113%. Similar stimulation of the contralateral CSN had little effect on the AN pressor response. Constant-frequency stimulation of the ipsilateral CSN also failed to enhance this response. Possible mechanisms of the interaction between these antagonistic reflexes were investigated. The results suggest that the augmentation of the AN pressor response results from a central neuronal interaction between these antagonistic reflexes.


Oxygen delivery in lambs: cardiovascular and hematologic development.

After birth a decrease in hemoglobin concentration occurs while high metabolic demands are imposed on the infant by the extrauterine environment. Using the resting lamb as a model, we studied the mechanisms that are called into play during this period to maintain oxygen delivery. Measurements were made of oxygen consumption, arterial and mixed venous blood oxygen contents, cardiac output, hemoglobin concentration, percent fetal hemoglobin, 2,3-diphosphoglycerate, and hemoglobin oxygen affinity during the first two postnatal months. There was a rapid decrease in hemoglobin concentration after birth and concomitant decrease in hemoglobin oxygen affinity, changes similar to those described in humans. Cardiac output and oxygen consumption were both very high immediately after birth and declined in parallel, so that arteriovenous oxygen content difference was constant. Thus at rest cardiac output varies as a result of the changing need for oxygen. This relationship is independent of hemoglobin concentration or oxygen affinity within the normal range. If, however, oxygen demands were increased, oxygen delivery might be compromised by a limited ability to increase oxygen extraction during the immediate newborn period or when hemoglobin concentration is lowest.


Analysis of oxygen diffusion from arteriolar networks.

A mathematical model of oxygen transport in the precapillary microcirculation is presented. The theory is then used to simulate oxygen distribution in the arteriolar network of the hamster cheek pouch. Theoretical prediction of transmural and longitudinal oxygen tension (PO2) gradients is in qualitative agreement with available experimental data. The effect of the variation of inlet network PO2, blood flow rate, blood hematocrit, and other parameters on the transport characteristics is studied. The calculations predict that the luminal PO2 in small arterioles is practically independent of the inlet network PO2 leve if the latter is sufficiently high; when this inlet PO2 level is low, then the longitudinal gradients of luminal PO2 vanish. It is further shown that retardation of blood flow may cause a significant increase in precapillary oxygen losses.


Renal circulatory effects of adrenergic stimuli in anesthetized piglets and mature swine.

The relative maturity of renal circulatory responses to efferent renal nerve stimulation, and to exogenous norepinephrine and isoproterenol, was tested in 62 piglets (1--16 days old) under pentobarbital anesthesia (10--25 mg/kg). Aortic pressure, heart rate, and renal and femoral arterial flows (measured by electromagnetic flow transducers) were recorded simultaneously. Renal vascular resistance was calculated as mean aortic pressure/mean flow. Transection of the renal nerve resulted in decreased renal resistance in all animals. Efferent renal nerve stimulation at increasing frequencies (2--12.5 Hz, at 1.2 ms pulse duration and 1.0 mA current) showed age-dependent differences in the threshold and also in the magnitude of increase in renal resistance. Norepinephrine (0.05--1.0 microgram/kg) caused age-dependent increases in renal resistance. Restoration of renal flow toward control level occurred during the peak pressor effect of norepinephrine only in older piglets. Isoproterenol (0.05--1.0 microgram/kg) did not alter renal resistance consistently in piglets younger than 1 wk. Phentolamine (0.25 mg/kg) attenuated or blocked resistance increases to 0.5 microgram norepinephrine/kg or to renal nerve stimulation at 12.5 Hz in all animals. Propranolol (0.1 mg/kg) attenuated or blocked resistance decreases to 0.1 microgram isoproterenol/kg, which occurred only in older piglets. These results indicate the presence of an active alpha-adrenergic vasoconstrictor mechanism and absence of the beta-adrenergic vasodilator mechanism in the renal circulation of swine at birth.


Myocardial cation contents during induction of calcium paradox.

Myocardial cation contents were measured in isolated rat hearts perfused under various conditions. Reperfusion of Ca2+-deprived hearts produced marked increases in myocardial Ca2+ and Na+ and decreases in Mg2+ and K+ contents. These changes were dependent on the Ca2+ concentration and duration of perfusion during the periods of Ca2+ deprivation and reperfusion. The loss of Ca2+ and K+ contents normally seen after Ca2+-free exposure as well as the reperfusion-induced changes were prevented if the Ca2+-free medium contained low (35 mM) Na+ or was cooled to 21 degrees C. Reperfusion with normal Ca2+, low Na+ medium augmented the increase in myocardial Ca2+ content, while reducing K+ or Mg2+ or increasing Mg2+ in the reperfusion medium had no effect. Addition of verapamil, D600, or propranolol to the reperfusion solution did not alter the reperfusion-induced cation changes observed using control medium. These data suggest that during Ca2+ depletion, the mechanisms responsible for regulating calcium influx are either lost or inactivated, so that reperfusion-induced changes are governed solely by the driving force favoring calcium influx. The occurrence of Ca2+ overload under this condition has been implicated in the irreversible damage to myocardium and contractile failure.


Indirect blood pressure determination by Doppler technique in renal hypertensive cats.

The Doppler ultrasonic recording technique was used to measure systolic and diastolic blood pressures indirectly in renal hypertensive cats. The accuracy of the method was evaluated by comparing indirect blood pressures from one leg of a cat with direct pressure measurements from the other leg. A linear relationship existed between indirect and direct systolic and diastolic pressures. The consistency of the method was assessed by measuring blood pressure during a 5-h monitoring period in normotensive and renal hypertensive cats. No significant variation occurred over this period. The sensitivity of the method to blood pressure changes was determined also. A significant reduction in systolic and diastolic pressure induced by hydralazine, 10 mg/kg po, was recorded during a 5-h monitoring period. The development of renovascular hypertension was followed for approximately 70 days. Systolic pressure rose in a logarithmic fashion from 160 to a maximum of 240 mmHg. It was concluded that the Doppler ultrasonic technique is a simple and reliable method for recording indirect blood pressure acutely and chronically in conscious unrestrained cats.


Preferential streaming of ductus venosus blood to the brain and heart in fetal lambs.

In 16 chronically prepared fetal lambs we compared the systemic distribution of ductus venosus blood flow with that of abdominal inferior vena caval blood by simultaneously injecting microspheres labeled with different radionuclides into an umbilical vein and into the abdominal inferior vena cava. A significantly greater proportion of ductus venosus blood flow than of abdominal inferior vena caval blood flow supplied the brain, heart, and upper body; this resulted from streaming of ductus venosus blood flow within the thoracic inferior vena cava with preferential direction of that blood flow through the foramen ovale. Blood flows to upper and lower body structures and placenta calculated from umbilical venous microsphere injections and reference arterial blood samples did not differ from those computed fromabdominal inferior vena caval injections and reference samples. Thus, despite streamline blood flow within the fetal thoracic inferior vena cava, organ blood flows can be accurately measured with either an umbilical venous or an abdominal inferior vena caval injection of microspheres when either is combined with the appropriate reference arterial blood samples.


Transjugular hepatic vein cannulation in rats with nonisotopic in vivo verification.

A simple, rapid and relatively atraumatic method for transjugular cannulation of the hepatic vein and for repeated sampling of hepatic venous blood in the rat is described. Preliminary in vivo verification of the cannula's position is proposed, either by using the glucose differential between consecutive samples of the hepatic venous blood and inferior vena cava blood, or more practically, by using the glucose differential between the hepatic venous blood and tail blood obtained simultaneously. The latter procedure is favored because of its technical simplicity.


Interactive effects of cognitive involvement and response topography upon differential eyelid conditioning to conceptual discriminanda.

The purpose of the experiment was to determine some cognitive differences underlying the superior differential conditioning of voluntary-form (V) over conditioned-form (C) responders. Two cognitive activities were hypothesized to be jointly necessary for the superiority of Vs: first, an active development of reinforcement contingency awareness by the subject himself, and, second, an active use of acquired contingency knowledge in predicting UCS occurrences. The first variable was manipulated by asking half of the subjects to "figure out" the contingencies, while the other half were fully informed of them at the start. The second variable was assessed by requiring half of the subjects to engage in a button-pressing US prediction task on each trial. Conditioned discrimination indicated that, as predicted, both of these cognitive activities were required for good performance by Cs, supporting the hypothesis that Cs are normally deficient in these respects. An unpredicted deterioration in discrimination for Vs when both task manipulations were imposed suggested that competition between the Vs' spontaneous cognitive activities and the experimentally imposed ones developed in the high external demand situation.


Immediate and final recall of pictures and words with written or oral tests.

Immediate and delayed recall of pictures and words was examined as a function of semantic or nonsemantic orienting tasks and the type of test (written or oral). As expected, semantic tasks generally led to greater final recall than nonsemantic tasks, with semantic tasks even producing positive recency on the delayed test. The evidence for a picture-word difference was largely restricted to the final recall of items involved in negative decisions; for such items the advantage of semantic tasks was apparent only for pictures. This suggests that "congruity" may be an important factor in picture-word differences, with such differences more apparent for the weaker items from negative judgments. Type of test did not seem to be a major factor in determining level of recall, suggesting that reinspecting the recall protocol during a written immediate test does not contribute substantially to final recall performance.


Positive contrast in the rat: a test of the additivity theory.

Rats were trained to lever press for food on a multiple variable-interval variable-interval schedule, then shifted to a multiple variable-interval extinction schedule. For six subjects (group L), schedule components were signalled by the presence or absence of a flashing light emitted from an alternate, "signal" lever. For four subjects (group T), schedule components were signalled by two distinct auditory tones. Contrary to the predictions of an additivity theory based on the summation of response classes, contacts on the signal lever did not increase after the schedule shift in group L. However, nine of the ten subjects in the study demonstrated positive contrast effects on the operant lever. In a subsequent test for stimulus control, enhancement and suppression by the discriminative stimuli were found in these same nine subjects. An additivity theory based on the summation of excitatory processes, rather than response classes, appears to account for these data.


Image latency and recall as functions of array size.

A comparison of image latencies and recall as a function of increasing arrays of objects involved three groups of subjects listening to descriptions of arrangements of objects and responding when they had visualized each array as a whole. After each latency response, one group of subjects indicated if they had visualized all the objects, another group free recalled, and a third group had no additional task. A fourth group recalled the arrays immediately after the end of the description. Increasing array size, and hence the demands on the resources of the visual imagery system, produced a concomitant exponential-like deterioration in performance according to the latency and recall measures. However, the deterioration in recall only started above arrays of four objects compared with an increase in latencies across these array sizes; so the latency function is not produced by the unavailability of information, at least for smaller array sizes. The group who immediately recalled did not remember spatial positional information concerning the middle serial positions of six-object arrays as well as the group who underwent wholistic visualization prior to recall, indicating that the wholistic visualization process can facilitate the coding of spatial information.


Fish (Tilapia aurea), as rats, learn shuttle better than lever-bumping (press) avoidance tasks: a suggestion for functionally similar universal reactions to a conditioned fear-arousing stimulus.

Fish learned a shuttle avoidance task faster than a lever-bumping task. The latter task was hardly mastered at all. These and other results tend to support the suggestion for functionally similar universal reactions to a conditioned fear-arousing stimulus.


Similarity effects in face recognition.

Three experiments are described which examine the effects of similarity on face recognition using a new application of hierarchical clustering analysis (HCS). Experiments I and II employed a within-groups design where subjects attempted to recognize targets among decoys from the same and different cluster to the target. Common cluster membership accounted for 72% and 84%, respectively, of all false alarms in the two experiments. Absolute error rates were affected by the number of targets actually present in the array and the style of the instructions given to subjects but were not influenced by whether successive or simultaneous test presentation was employed. Experiment III used a between-subject design where targets were embedded in arrays composed from same or different clusters. False alarm rates were significantly higher for the same cluster condition, but hit rates were unaffected by recognition context. The significance of these findings for theories of face identification is discussed.


Some problems encountered in the psychoanalytic treatment of overt male homosexuality.

This article describes certain theoretical and clinical problems commonly met with during the psychoanalytic treatment of adult homosexual patients. Difficulties discussed are selected out of extensive clinical experience and are described under several headings: general problems, such as selection of patients, motivation for seeking therapy, problems at the outset; the working alliance and its maintenance; transference problems and the issue of analyzability; problems secondary to deficiencies in the structure of the ego of the homosexual patient; the imperativeness of the homosexual impulse and the problem of acting out; extrinsic problems.


Group psychotherapy with acting-out patients: specific problems and technique.

Severe crises bring acting-out patients to psychotherapy. In order to keep them in treatment, the therapist has to educate them about what psychotherapy is. An explanation of the tasks of psychotherapy, as well as of patient and psychotherapist is required. Factors unique to these patients have to be taken into account. The author's experience demonstrates that group psychotherapy is preferable to individual therapy. Case examples are cited.


A practical approach to the psychotherapy of the borderline patient.

Guidelines for the ordinary psychotherapist in the day-to-day office treatment of so-called borderline patients are presented. Practical pointers for handling problems of diagnosis, working alliance, transferences, middle phase, and termination are given, followed by a brief discussion of the future of the concept of borderline patient.


Toward unification of psychotherapies: a complementary model.

The emergence of different models of psychological healing from Freud to the present, and specific features which characterize "new" psychotherapies in contrast to psychoanalysis are examined. The author maintains that these represent a chronological evolution of therapeutic forms which are complementary and which portend the unification of the psychotherapies.


The therapeutic relationship in brief psychotherapy.

Brief psychotherapy is predicated upon a thorough knowledge of psychodynamics and careful conceptualization of each individual's psychopathology. Areas and methods of intervention must be concisely selected and clearly goal-related. As a modality, I see brief therapy relating to traditional therapy the way a short story relates to a novel. It takes special skill and expertise.


Differential diagnosis and therapeutic handling of communication barriers.

Encouragement of open, direct communication between members of a dyad may produce favorable or unfavorable results, depending upon the situation. The author presents a system of classifying communication barriers, designed to help the therapist decide when to encourage open communication and when to support the withholding of communication of certain sorts until other therapeutic goals have been achieved.


Termination: that difficult farewell.

Termination is usually a difficult and painful, yet powerfully significant life experience. It is experienced in multiple contexts beginning with birth and ending with death. This article addresses itself to these issues and the when and how of goodbyes.


The nurturing of medical students: a psychotherapeutic approach to psychiatric education.

Students' resistances to learning psychiatry and their difficulties in relating to disturbed patients are both due largely to their own anxieties. Therefore it is both necessary and possible for the teacher to give them effective psychotherapeutic help as and when required as an integral part of the educational process.


The role of a directly observed, continuous case conference in the training of child psychiatrists.

The directly observed, continuous case conference is studied in depth as a format for teaching child psychotherapy. The effects of group dynamics, direct observation, and the specific case on the processes of therapy, learning, and supervision are examined. Six guidelines are set forth to maximize the effectiveness of the conference.


Munchausen's syndrome: an unusual case.

Unlike most Munchausen patients, Miss A. was willing to define herself as a psychiatric, as well as a medical-surgical patient. Consequently, it was possible to engage her in therapy in which observation could occur. It was found, also, that Miss A. had used eye drops to dilate her pupils to simulate a neurological disorder and had accidentally induced an anticholinergic delirium.


Tarsonemid mites in Danish house dust.

From a study of 98 typical Danish city apartments it was found that pyroglyphid and tarsonemid mites dominated the housedust acarofauna. Both groups of mites show a remarkable similarity in their occurrence and dependence on the microclimate. Room air humidities above 7 g water/kg dry air involved the highest densities. Below this limit only background contamination appeared. At least 14 distinct forms of tarsonemid mites were found, with Tarsonemus floricolus Can. & Fanz., 1876 as the dominating species. As tarsonemid mites were found regularly rather than occasionally, it is suggested that these mites may be responsible for at least a part of the cases of housedust allergy that cannot be ascribed to the content of Dermatophagoides mites in the housedust.


Comparison of skin tests and RAST for the diagnosis of bee sting allergy.

Skin tests and estimation of specific IgE-antibodies by the RAST are evaluated as diagnostic procedures in bee sting hypersensitivity with the followiny extracts. (2) With bee venom results of skin tests and RAST correspond in 82%, with bee wholebody extracts in 68%. (3) Both with skin tests and the RAST with bee venom a good discrimination between patients with bee sting hypersensitivity and non-allergic controls is observed. Skin tests with bee venom are somewhat more sensitive than bee venom-RAST. (4) With the careful skin test procedure chosen, no adverse reactions were observed.


Dust mites. A 1-year study.

Mattress dust was collected by out-patients attending hospital for respiratory allergic problems. The dust mites were counted in "pool" samples of 100 mg. Each sample represented a single month's collection. The mites were classified according to family: Pyroglyphidae and Cheyletidae. Those not belonging to either of these two families were classified as "other mites". Temperature and humidity during the period of the study showed no correlations with the number of mites. There was a statistically significant correlation between the various mite groups.


Reversal of neuromuscular blockade by glycopyrrolate and neostigmine. A study of the effects on lower oesophageal sphincter tone.

The effect of intravenous glycopyrrolate and neostigmine, a drug combination routinely given to antagonize non-depolarising neuromuscular blockade, on lower oesophageal sphincter tone was studied in twenty patients undergoing Caesarean section. Glycopyrrolate 0.6 mg and neostigmine 2.5 mg i.v. increased LOS pressure insignificantly by a mean of 0.2 kPa (P less than 0.1). In contrast, glycopyrrolate 0.6 mg and neostigmine 5 mg increased LOS pressure by a mean of 1.2 kPa (P less than 0.001). The latter dosage of this drug combination thus appears preferable in patients presenting for emergency surgery, if the integrity of the lower oesophageal sphincter is to be maintained during extubation and recovery from general anaesthesia.


A survey of infection in an intensive care unit. "Forewarned is forearmed".

The infection (36%) and mortality rates (28%) were investigated in 433 patients admitted to a Respiratory Intensive Care Unit. It was found that the mortality rate was higher (45%) in the infected group than in the non-infected group (19%) and particularly so in patients who had had intra-abdominal surgery or who remained in the unit for longer than a week.


Paravertebral thoracic block-a reappraisal.

An accurate, simple and safe method, based upon cadaver studies, of obtaining a thoracic paravertebral block, suitable for repeated administration by catheter or for permanent accurate neurolytic block, and which carries significant advantages over intercostal or epidural block, is described in theory and practice.


The Swan-Ganz pulmonary artery catheter. Incidence of complications, with particular reference to ventricular dysrhythmias, and their prevention.

A series of seventy-three adult patients undergoing open-heart surgery was studied, in whom a Swan-Ganz pulmonary artery catheter was inserted. The incidence of complications occurring during insertion and use of the catheter was noted, and a controlled trial carried out to determine the efficacy of lignocaine 1 mg/kg iv in preventing ventricular dysrhythmias during passage of the catheter. A significant decrease in dysrhythmia rate was observed. Ways of minimising or preventing other complications are discussed.


Ethamsylate and blood loss in total hip replacement.

Nineteen consecutive patients undergoing total hip replacement under epidural anaesthesia were randomly divided into two groups. The treatment group received 1000 mg of ethamsylate intravenously before induction of anaesthesia. Blood lost during surgery was measured by a colorimetric technique. Closed suction drains were used and all blood lost after operation collected for measurement. Ethamsylate did not decrease the average volumes of blood lost during or after the operation. Neither did it reduce the requirements for blood transfusion. Although there were no side-effects attributable to ethamyslate, there seems to be no indication for its use in total hip replacement under epidural anaesthesia.


Architecture of the mesonephric nephron in pig and rabbit.

As a precondition for determining nephron profiles in sections, mature mesonephric nephrons from pig and rabbit embryos were isolated by a maceration technique in order to demonstrate nephron architecture, length, and diameter. In the pig the proximal tubule is largely constant. In the distal tubule the pre-attachment zone shows the greatest variation. The zone of attachment ot the corpuscle and the ventrolaterally directed post-attachment coil has a predictable course as does the collecting tubule. In contrast to earlier reports, the nephron shows no drastic differences in tubule diameter and is up to 33 mm long. The proportional length of the three major nephron segments is surprisingly constant. The rabbit nephron, although much shorter (4 mm) and simpler, with an alomst S-shaped pattern, is less easily understood in sections. Marked irregularities in its course are caused by the different behaviour of the terminal proximal segments. The distal tubule shows an ampullary dilatation in the attachment zone but can be very narrow in the pre-attachment part.


Scanning and light microscope studies of the development of the chick embryo semilunar heart valves.

The development of the semilunar valves of the great arteries was studied by light and scanning electron microscopy in the chick embryo. The results show that three distinct developmental periods can be distinguished. The formation of the anlage of the valves takes place in the first period (stages 26--29). These early anlage consist of three pyramidal shaped cusps formed by a core of loosely packed mesenchymal cells covered by a flattened endothelium. In the second period (stages 30--35) the cusps undergo excavation on their distal face. Morphololgical evidence is reported suggesting that this excavation process is produced by an initial solid ingrowth of the endothelium of the arterial face of the cusps which is immediately luminated by detachment of cells towards the bloodstream and by cell death. The histogenesis of the valves takes place in the third period (from stage 36 until hatching). It was observed that during this period some myocardial cells of the outflow tracts of the ventricles invade the valvular tissue and that in the upper part of the cusps a prominent fibrous layer is formed.


A quantitative approach to cytoarchitectonics. IV. The areal pattern of the cortex of Galago demidovii (e. Geoffroy, 1796), (lorisidae, primates).

The boundaries of neo- and allocortical areas of Galago demidovii are analyzed with an automatic quantitative procedure using an image analyzer. The results are summarized in a cortical map and compared with a cortical map of Tupaia. Galago shows a highly differentiated temporal lobe and no homogeneous peristriate area comparable to the classical concept of Brodmann's Area 19. Primary motor, somatosensory, auditory, and visual areas are delineated and shown to be surrounded by distinct secondary areas.


An electron microscopic study of periderm cell development in mouse limb buds.

Development of periderm cells covering fore- and hindlimb buds of mouse embryos was observed by scanning and transmission electron microscopy at half day intervals from day 9.5 to 12.5 of gestation (vaginal plug = day 0). At day 9.5, the epidermis is single layered. Occasional periderm cells are present at day 10.5. By day 11.5 a complete layer of periderm cells has covered the entire limb bud. By scanning electron microscopic observation, periderm cells covering the apical ectodermal ridge (AER) are characterized by a small surface size and an elongated polygonal shape with the long axis parallel to the antero-posterior contour of the apical rim. Periderm cells covering the dorsal and ventral surfaces of the limb bud are relatively large and have a polygonal surface shape. The periderm covering the apical tip reflects well the developmental state of the AER. Hence, it is possible to estimate the development of the AER by observing the surface features of the apical periderm by scanning electron microscopy.


Epithelial-mesenchymal interactions in differentiation of stomach epithelium in fetal mice.

Epithelial-mesenchymal interactions during development of the forestomach and glandular stomach in fetal mice were investigated by recombination experiments in vitro. Stomach epithelium could not survive when cultivated alone, but its development was supported by the presence of homologous or heterologous mesenchyme. The developmental fate of the epithelium was not affected by recombination with heterologous mesenchyme, but the expression of epithelial differentiation was influenced by the type of mesenchyme. The rate of keratinization of the forestomach epithelium was significantly greater on recombination with homologous mesenchyme than on recombination with heterologous mesenchyme. Moreover, the rate of formation of glandular structures in the glandular stomach epithelium was significantly greater on recombination with 16.5-day stomach mesenchyme than on recombination with 14.5- or 18.5-day stomach mesenchyme.


Histological analyses of lethal yellow mouse embryos (Ay/Ay) at 90 and 132 h post coitum.

Strain C57BL/6J-Ay/Ay embryos are developmentally retarded in utero at 90 hpc and are resorbed by 132 hpc. The Ay/Ay developmental delay previously observed in vitro has now been confirmed in vivo. Apparently Ay is involved in some aspect of cleavage stage metabolism.


The timing and sequence of events in the development of the human vertebral column during the embryonic period proper.

A documented scheme of the early development of the human vertebrae is presented. It is based on (1) reports of workers who personally studied staged human embryos, and (2) personal observations and confirmations. The necessity of studying staged embryos in order to determine the precise sequence of developmental events is stressed.


Early testicular development in sex reversed mice.

A comparison is made of two sets of data bearing on the development of testes in XX, Sxr mice. Although Spoljar and Drews (1978) reported no significant difference in the growth rates of XX and XY testes, nevertheless their data suggest that such a difference may exist. This confirms earlier work by Mittwoch and Buehr (1973), who found the testicular volumes of XX embryos aged 15 and 16 days to be below those of XY embryos.


An early development defect in the cerebral cortex of the reeler mouse. A morphological study leading to a hypothesis concerning the action of the mutant gene.

Brains of reeler and normal mouse embryos have been studied on semi-thin sections and with Golgi impregnations. No change can be seen in the neuroepithelium or in the primary cortical organization. The first evidence of a morphological abnormality appears at E 14, in the cortical plate. Instead of being closely packed and radially oriented, nerve cells are loosely arranged and show quite variable orientations of their long axis and apical dendrite. The axons run obliquely through the cortical plate and do not display the characteristic angular course seen in the normal animal. It is suggested that the primary defect in reeler mice may be in the plasma membrane of cortical plate cells, resulting in a loss of their capacity for mutual recognition and binding. This could account for the cytoarchitectonic disorganization in this mutant, especially the absence of a molecular layer and the inversion of the histogenetic gradient in the developing cerebral cortex.


Acetylcholinesterase-containing neurons of layer VIb in immature neocortex: possible component of an early formed intrinsic cortical circuit.

In this ontogenetic study the neurons of layer VIb of rodent somatosensory cortex have been characterized using acetylcholinesterase (AchE) histochemistry, Golgi, and electron microscopic techniques. Already, at birth, the neurons were found to be AchE-rich. They contain presumed AchE reaction product within their granular endoplasmic reticulum. These cells send fine axons upwards towards the subpial layer where they terminate in a dense, AchE-rich, fiber plexus. In chronically undercut cortex, AchE staining persists in layer VIb neurons and in the subpial fiber plexus. These observations continue to support the view that there is an intrinsic neuronal circuit connecting layer VI with I in immature neocortex. The findings also raise the possibility that the putative circuit is cholinergic.