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Biomedical subjects

H Kaufman

Publications and source records attributed to H Kaufman.

At least 73 records · Page 4Linked to original sources
PubMed1984

Premature thelarche--natural history and sex hormone secretion in 68 girls.

Data obtained during long-term follow-up of 68 girls with premature thelarche were analysed. In 85% onset was before the age of 2 years, in 30.8% being present at birth. In 44.1% there was a regression after 3 2/12 +/- 2 8/12 years (SD). Basal levels of plasma FSH and response to LH-RH were significantly higher than prepubertal controls (1.93 +/- 1.56 vs. 0.8 +/- 0.1 mU/ml and peaks 12.3 +/- 5.4 vs. 7.9 +/- 1.0 mU/ml respectively; p less than 0.001). Twenty-seven of 52 patients tested had increased plasma estradiol and in 27 of 40 patients tested, urocytograms or vaginal smear showed estrogenization. Basal levels of LH and response to LH-RH were prepubertal. The girls with premature thelarche were significantly taller than normal controls of the same age (p less than 0.001). These results suggest that premature thelarche is an incomplete form of precocious sexual development probably due to derangement in the maturation of the hypothalamo-pituitary-gonadal axis which results in a higher than normal secretion of FSH, as well as a defect in the peripheral sensitivity to the sex hormones.

17-Ketosteroids↗
PubMed1984

The effect of fixation on corneal endothelial cell dimensions and morphology in scanning electron microscopy.

Soft tissue specimens shrink during fixation, dehydration and critical point drying when prepared for scanning electron microscopy (SEM). This can cause serious artifacts not only in 'compact' tissues but especially in hollow structure, like the eye, where the chambers are lined by delicate layers such as the corneal endothelium. In this study various glutaraldehyde and formaldehyde fixations at different concentrations with or without 5% sucrose were tested. Dimensional as well as morphological changes of rabbit corneal endothelial cells were evaluated. The mean surface diameter and area of rabbits' central corneal endothelial cells were measured first in vivo by specular microscope. Thereafter the same corneas were fixed in 9 different solutions and processed for scanning electron microscopy. The surface structure of the same endothelium was then photographed with SEM. The cell dimensions were remeasured. According to our results 1.25% or 2.50% glutaraldehydes without sucrose gave the best surface preservation and caused the least shrinkage.

Animals↗
PubMed1984

Salt loss in hypertensive form of congenital adrenal hyperplasia (11-beta-hydroxylase deficiency).

Studies in patients with congenital adrenal hyperplasia due to 11-hydroxylase deficiency (11-OHD) suggest a common defect in the adrenal zona fasciculate and zona glomerulosa. The hypertension in untreated 11-OHD patients is considered to be secondary to the accumulation of deoxycorticosterone as a consequence of inadequate 11-beta-hydroxylation in the biosynthesis of aldosterone, and is alleviated by glucocorticoid suppression. To investigate whether deoxycorticosterone suppression in these patients resulted in loss of salt, 11 patients with 11-OHD aged 4-26 yr were studied. Patients were evaluated during dexamethasone suppression (0.6 mg/m for 2 weeks) while receiving a normal diet and a low salt diet (10 meq Na/24 h). There was no significant change in serum electrolytes, cortisol, 11-deoxycortisol, and DOC during these two dietary regimens. PRA in the recumbent and upright positions on both diets was significantly higher in the patients than in normal subjects. Plasma or urinary aldosterone levels were significantly lower in the 11-OHD patients than in the normal controls. Moderate salt loss occurred during the low salt diet. It is concluded that sodium retention is incomplete in glucocorticoid-treated 11-OHD patients. Partial sodium retention is maintained by increased PRA and a subnormal aldosterone response. 11-OHD patients should be carefully monitored during acute disease states and, when electrolyte imbalance is suspected, treatment with mineralocorticoid should be considered.

Adolescent↗
PubMed1984

The influence of trauma from occlusion on the bacterial repopulation of periodontal pockets in dogs.

Pockets were surgically created in the two upper external incisors of four beagle dogs, and a copper band adapted to prevent reattachment. After 4 weeks the copper bands were removed, the teeth scaled and root-planed and crowns placed on both experimental teeth in such a way that one of them was forced bucally when the teeth occluded. An orthodontic appliance anchored in bands cemented to the cuspid teeth brought the tooth back to its original position when disclusion occurred. Experimental time was 12 weeks. Clinical indices and bacterial samples for darkfield examination were taken at baseline and weekly thereafter. The dogs were fed a diet that favored plaque accumulation and no oral hygiene was performed. Surgically created pockets initially became populated by cocci (65%-75%) and small amounts of motile bacteria (12%-15%) including 3% to 4% spirochetes. In 4 weeks the percentage of cocci declined steadily (42%-45%) and motile bacteria increased to 37% to 43% with spirochetes representing 24% to 27%. After scaling and root planing, the number of cocci increased again and motile bacteria declined although the baseline values were not reached. This decline persisted for 2 weeks after scaling. Repopulation of the pocket in traumatized and nontraumatized teeth followed the same initial pattern, taking again 5 weeks to return to prescaling levels. No difference was found between traumatized and nontraumatized teeth. Clinical measurements, however, revealed a statistically greater loss of attachment in traumatized teeth as compared with nontraumatized teeth.

Animals↗
PubMed1984

Direct estimation considered within a comparative judgment framework.

Two experiments that employed the dimension of line length were conducted to support an interpretation of direct estimation within the framework of comparative judgment. It was reasoned that because memorial and processing demands increased, decreasing amounts of transmitted information should be found in discrimination, categorization, and estimation tasks when considered in that order. The data of the first experiment supported the prediction. However, external anchors provided to reduce demand in estimation had no apparent effect. A second study did indicate a marginal effect of anchors when subjects were instructed to employ them but, more strikingly, demonstrated that the shape of the psychophysical function was sensitive to the differential labels that accompanied the anchors. Labels derived from a Fechnerian assumption about psychophysical relations produced a Fechnerian function, whereas labels derived from the actual ratio of the stimulus line to the largest line produced a function consistent with Stevens's power law. It was concluded that the evidence favored a view of direct estimation consonant with cognitive interpretations rather than with the idea of a universal psychophysical function.

Cognition↗
PubMed1983

Effect of chlorpromazine on hypothalamic-pituitary-gonadal function in 10 adolescent schizophrenic boys.

Low basal plasma testosterone levels with normal response to human chorionic gonadotropin (HCG) stimulation and mild hyperprolactinemia and blunted luteinizing hormone (LH) response to luteinizing-releasing hormone (LRH) stimulation were found in 10 adolescent schizophrenic boys who had been treated with chlorpromazine for more than 6 months. These findings may indicate a disturbance of the hypothalamic-pituitary-gonadal function in these patients, probably due to the prolonged administration of chlorpromazine. It remains to be established whether the decrease in basal testosterone secretion is caused directly by chlorpromazine or secondarily by the drug-induced hyperprolactinemia.

Adolescent↗
PubMed1982

Adrenocortical function in children with precocious sexual development during treatment with cyproterone acetate.

Adrenal function was studied in thirty-two children with precocious sexual development who were being treated with cyproterone acetate (CPA) at doses ranging from 68 to 175 mg. m2. day for periods lasting from 2 to 79 months. In eighteen children the adrenocortical function evaluation was made before and during CPA treatment. In these eighteen patients, the mean basal plasma cortisol level during the morning hours was 11.2 +/- 4.6 micrograms/dl (m +/- SD) before treatment and fell significantly to 7.2 +/- 4.1 micrograms/dl (P less than 0.02) during therapy. In fifteen patients tested during insulin hypoglycaemia the cortisol peak fell from 21.6 +/- 5.5 micrograms/dl before treatment to 16.7 +/- 6.8 micrograms/dl (P less than 0.05) during CPA therapy. There was a significant inverse correlation between this peak and the dose of CPA but no correlation was found between the cortisol response and duration of treatment. In eight of twenty patients tested, urinary free cortisol levels were undetectable during treatment. No change in basal plasma ACTH levels were demonstrated using standard radioimmunoassay techniques. In the patient receiving the highest dose of CPA and showing complete suppression of the adrenal axis, prolonged stimulation with ACTH-Depot demonstrated a responsive adrenal gland. Addition of a replacement dose of cortisol to the CPA treatment led to the rapid development of the typical signs of Cushing's syndrome. It was concluded that despite the evidence of adrenal suppression by CPA, cortisol supplementation is not necessary and may not even be contraindicated.

Adrenal Cortex↗
PubMed1982

Neurosurgery in a different society: the People's Republic of China.

An interdisciplinary clinical neurosciences delegation representing the International Committee of the Congress of Neurological Surgeons visited the neurosurgical departments of major teaching hospitals in five cities of the People's Republic of China. This report describes the clinical and research activities observed, with reference to the unique social, political, economic, and cultural environment in China. Although facilities and equipment are limited, diagnostic accuracy and surgical technique are excellent. Results for certain disorders seemed comparable to those obtained in western neurosurgical centers. Given the clinical expertise of our Chinese colleagues and the large numbers of cases treated in Chinese medical centers, a significant contribution to neurosurgical knowledge can be expected from the exchange of information and future collaboration that have now become possible.

Acupuncture Therapy↗
PubMed1982

Late-onset type of 21-hydroxylase deficiency in childhood.

It was recently proposed that congenital and late-onset 21-hydroxylase deficiency are caused by two distinct recessive allelic genes. Although both genes are associated with the HLA system, only the late-onset type was found to be linked with the antigens B14 and DR1. Biochemical and immunological studies were conducted in two families with children suffering from 21-hydroxylase deficiency of postnatal onset. In the first family, of Jewish Ashkenazic origin, a 2 1/2-yr-old girl presenting with clitoromegaly was found to be homozygous for the antigens B14 and DR1. In the second family, of Arabic origin, all the children, their parents and a paternal aunt were clinically and/or biochemically affected, carrying the B14, but not the DR1 antigen on one or both HLA haplotypes. These data suggest that some cases of simple virilizing 21-hydroxylase deficiency in childhood are related to the late-onset type of 21-hydroxylase deficiency.

Adrenal Hyperplasia, Congenital↗
PubMed1982

A new method of magnifying photographic images using the scanning electron microscope in the backscattered electron detection mode.

This paper describes a new method of magnifying small images in photographic film by means of a scanning electron microscope (SEM) operated in the backscattered electron detection mode. The study included tests of several types of radiographic film, transmission electron microscopy film, and black and white 35 mm film. The electron optical enlargement method is particularly useful in situations where the film sample is opaque to light and for generating enlarged images at magnifications beyond the reach of light optical enlargement methods, i.e. up to approximately 2000X with ease and rapidity in a single step. The electron optical enlargements compare favorably in contrast and detail with the enlargements made with a light microscope and with a darkroom enlarger.

Breast Diseases↗
PubMed1981

Clinical evaluation of the effects of combined treatment with bromocriptine and spironolactone in two women with the polycystic ovary syndrome.

Two women with the polycystic ovary syndrome were treated with bromocriptine (15 to 20 mg/day) in combination with spironolactone (100 mg/day). In the first woman the combined therapy induced a marked reduction of hirsutism, with ensuing ovulation and pregnancy. In the second woman, who had hyperthecosis and had been refractory to treatment with clomiphene and wedge resection, the combined therapy resulted in abolition of hirsutism, normalization of blood pressure, weight reduction, and improvement in glucose intolerance. In this patient fertility could not be established by the above treatment, but the symptomatic amelioration was so great that she accepted no further attempt to induce ovulation. In view of the marked amelioration of the polycystic ovary syndrome induced by combined bromocriptine and spironolactone treatment, this mode of therapy should receive further consideration.

Adult↗
PubMed1981

Addison's disease associated with precocious sexual development in a boy.

An eleven-year-old boy was diagnosed to have Addison's disease with an ACTH level of over 4500 pg/ml after a short episode of fever and dehydration. From the age of 6 years his skin and buccal mucosa had been hyperpigmented but there were no other subjective complaints. The clinical examination also revealed signs of advanced puberty for his age (3rd--4th stage according to Tanner's criteria), with advanced bone age (13 years). The elevated levels of plasma testosterone and gonadotropins and their response to LH-RH stimulation were appropriate for his clinical stage of puberty and supported the diagnosis of true precocious puberty. It is proposed that the concomitant appearance of Addison's disease and precocious puberty is due to a "drift" phenomenon of LH-RH and/or gonadotropins following the prolonged elevation of ACTH secretion.

Addison Disease↗
PubMed1981

Successful treatment of polycystic ovary syndrome with spironolactone or bromocriptine.

Marked improvement in the severe hypertension (250/150 mmHg) and hirsutism of a patient suffering from polycystic ovary syndrome was quickly achieved by the use of spironolactone 200 mg per day. Substitution of spironolactone with bromocriptine induced further amelioration of these symptoms and renewal of ovulatory cycles. These drugs may afford another mode of therapy in patients with polycystic ovary syndrome.

Adult↗
PubMed1980

Follow-up of boys with unilateral compensatory testicular hypertrophy.

Of a total of 148 boys with unilateral compensatory testiculary hypertrophy (CTH) diagnosed at our clinic, 30 were followed for many years throughout puberty. These boys underwent the pubertal stages fo pubic hair development in a normal manner, including penile growth. The basal plasma levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) of the boys with CTH showed a wider range than those of normal boys. Even in prepuberty the mean basal plasma FSH levels were significantly higher than those of normal boys, as was the peak FSH response to intravenous LH-releasing hormone. In puberty stage 4 the mean plasma LH levels were also higher than normal. Plasma testosterone levels were within the normal range in pubertal stages 1 to 4, but in stage 5 the mean basal level and response to stimulation with human chorionic gonadotropin were significantly lower than normal. Among seven spermatograms performed, five showed oligospermia and two showed azoospermia. It is concluded that compensatory hypertrophy of one testis does not seem able to prevent testicular insufficiency in adulthood.

Adolescent↗
PubMed1980

Effect of tumor removal on the presence of lymphocytic cortisol metabolism-enhancing factor in plasma of cancer patients.

Because lymphocytic cortisol metabolism-enhancing factor (LCMEF) is absent in the plasma of cancer patients (CP), this study was undertaken to determine the influence of tumor removal on this phenomenon. Known concentrations of human lymphocytes were incubated with cortisol in media containing 50% phosphate-buffered saline (PBS) and 50% of one of the following: a) homologic normal plasma (HP),b) plasma from patients with noncancerous diseases (NCD) before surgery, c) plasma from patients with NCD after surgery, d) plasma from CP before tumor removal, e) plasma from CP after tumor removal, f) plasma from long-surviving CP (LSCP), and g) PBS. With the exception of plasma from the LSCP group, all the plasma had the capacity to enhance the lymphocytic cortisol metabolism (LCM) when compared with that of PBS. There was no significant difference between the metabolism obtained with HP and that obtained with plasma from patients with NCD either before or after surgery. The plasma from CP led to a significant reduction in activity, with no significant difference in conversion rates before and after tumor removal. The plasma from LSCP failed to enhance LCM, had a conversion rate similar to that of PBS and significantly lower than that of the plasma from CP, and appeared to contain no LCMEF. These findings, which showed that the lack of LCMEF in CP is not influenced by tumor removal, may indicate 1) that the lack of LCMEF preceded the appearance of cancer or 2) irreversibility of a possible anti-LCMEF synthesis effect was induced by the tumor.

Biological Products↗