PubMed Health⌕ Search

Biomedical subjects

S A Kaplan

Publications and source records attributed to S A Kaplan.

At least 19 recordsLinked to original sources
PubMed1992

Arteriovenous malformation of ureter.

Congenital arteriovenous malformations of the genitourinary tract are rare. We report the first case of an arteriovenous malformation of the ureter. The patient presented with recurrent hematuria and left flank pain. Evaluation included an intravenous urogram, cystoscopy, and retrograde pyelography. A pedunculated lesion thought to be a fibroepithelial polyp was seen at the time of ureteroscopy, and the lesion treated by excisional biopsy and fulguration. Pathologic examination demonstrated an arteriovenous malformation. After thirty-month follow-up, the patient remains asymptomatic and free of recurrence.

Adult↗
PubMed1992

The cholinergic and purinergic components of detrusor contractility in a whole rabbit bladder model.

Whole rabbit bladders were suspended in a bath chamber and stimulated with ATP, bethanechol, electrical field stimulation, and bethanechol + ATP. Detrusor pressure and fluid expelled by the bladder were recorded, synchronized, and digitized. Detrusor work and power were calculated with a computer program. Maximum work was 61.4 +/- 28.7, 83.3 +/- 17.0, 85.0 +/- 15.0, 90.8 +/- 13.1 cm. H2O, ml. for ATP, bethanechol, electrical and bethanechol + ATP, respectively. Maximum power generated by ATP was 4.8 +/- 3.0 cm. H2O, ml./sec and was approximately 66% of that generated by bethanechol, and 50% of that generated by electrical stimulation, and bethanechol + ATP. ATP cannot empty the bladder with moderate outlet resistance while bethanechol and electrical stimulation can. Our results suggest that ATP is able to generate detrusor power and achieve work in bladder emptying. However, ATP generated power and work is considerably less than that of electrical stimulation or bethanechol alone. ATP mediated contraction is not inhibited by atropine or tetrodotoxin but is inhibited by P2 purinoceptor desensitization, suggesting a functional role of purine receptors on detrusor smooth muscle. Since ATP generated pressure is more rapid than with bethanechol alone, we support the hypothesis that ATP may be important in the initiation of micturition.

Adenosine Triphosphate↗
PubMed1992

Prostate specific antigen density: a means of distinguishing benign prostatic hypertrophy and prostate cancer.

Isolated prostate specific antigen (PSA) determinations in asymptomatic individuals have not demonstrated sufficient sensitivity and specificity to be useful in the routine evaluation of prostate disease. To enhance the accuracy of serum PSA we have used a quotient of serum PSA and prostate volume, which we refer to as prostate specific antigen density (PSAD). Prostate volume in this study was calculated from magnetic resonance imaging determinations of benign prostatic hypertrophy (BPH) or from the dimensions of the surgical specimen of cancer using the formula, length x width x depth x 0.5 = volume. A total of 61 patients with prostatic disease clinically confined to the prostate glands (41 with prostate cancer undergoing radical prostatectomy and 20 with BPH) was evaluated. The mean PSAD for prostate cancer was 0.581 while that for BPH was 0.044 (p less than 0.002). No patient with BPH had a PSAD of greater than 0.117 and only 1 patient had a density of 0.1 or greater. Of 34 patients with a PSAD of 0.1 or greater 33 had prostate cancer. Only 2 of the 41 prostate cancer patients and 14 of the BPH patients had a PSAD of 0.05 or less. There were 11 patients with a PSAD of greater than 0.05 and less than 0.1, including 6 with prostate cancer (1 with P0 disease) and 5 with BPH. Of the 6 prostate cancer patients 5 had a PSA of 4.0 or less and among the 5 patients with BPH 4 had a serum PSA of greater than 4.0 and 1 had a PSA of greater than 10. These results suggest that PSAD may be useful in distinguishing BPH and prostate cancer.

Antigens, Neoplasm↗
PubMed1992

Prostatic and periprostatic interstitial temperature measurements in patients treated with transrectal thermal therapy (local intracavitary microwave hyperthermia).

One of the questions raised regarding the use of transrectal thermal therapy in the treatment of benign prostatic hyperplasia (BPH) is whether there is a uniform and safe temperature distribution within the prostate. Our study represents the first attempt in humans to map the interstitial thermal distribution in the prostate during transrectal thermal therapy. With the patient under local anesthesia and under ultrasound guidance, a transperineal 3-point thermocouple was placed into various areas of the prostate in 15 patients. Prostatic-urethral thermocouple distance ranged from 1 to 3 cm. A urethral catheter containing a 5-point linear array thermocouple was placed and the balloon was inflated so that the proximal point was at the bladder neck and the remaining points were at 1 cm. intervals along the prostatic urethra. Power (25 watts) was delivered via the Primus (Technomatix) transrectal microwave applicator with simultaneous cooling of the rectal mucosa (between 12 and 14C). Treatment was delivered for 60 minutes and temperatures were recorded. In the prostatic substance a maximal temperature of 45C was observed during the heat-up phase and this decreased as the vasoactive response occurred. Temperature along the prostatic urethra varied between 40 and 43C and never exceeded 44C. A similar distribution of temperature was registered in the thermocouple points in the prostatic substance. The anticipated thermal dose of 41.5 +/- 1C for 60 minutes was achieved in the prostatic substance as measured by the sensors in the prostatic urethra and interstitial sensors. The results suggest that transrectal thermal therapy delivers a uniform and safe distribution of heat in the prostatic substance and urethra. Clinical trials are currently underway to ascertain the efficacy of transrectal thermal therapy in the management of BPH.

Adult↗
PubMed1979

Primary ovarian failure, juvenile rheumatoid arthritis, and vitiligo.

A female adolescent with primary ovarian failure was found to have circulating autoantibodies to her ovaries. Primary ovarian failure in pediatrics is usually attributed to gonadal dysgenesis. Autoimmune oophoritis is a rare cause and is most often associated with Addison's disease and other autoimmune endocrinopathies. Our patient also had juvenile rheumatoid arthritis and vitiligo. To our knowledge, this case represents the first reported instance of this particular constellation of autoimmune disorders.

Adolescent↗
PubMed1979

Relative usefulness of three growth hormone stimulation screening tests.

One hundred ninety-one children were tested by one of three screening procedures for growth hormone deficiency over a five-year period. Sleep screen yielded a 31.3% false-positive rate; levodopa administration alone yielded a 20.5% false-positive rate and levodopa in combination with propranolol yielded a 5.2% false-positive rate. These results support the view that the combined levodopa-propranolol hydrochloride screen test is superior to either the sleep or the levodopa screen tests in limiting the number of false-positive results and thus the need for further, more extensive testing.

Child↗
PubMed1979

Use of growth hormone-gel.

We evaluated the efficacy of a depot preparation of growth hormone (GH) in a 15% gelatin solution (GH-gel) in the treatment of 15 growth hormone-deficient children. The studies were designed to see if prolonging absorption of GH to achieve lower more physiological concentrations of GH in plasma would decrease the frequency of injection, reduce the amount of GH needed for effective therapeutic response, and improve the response to long-term treatment. We found that after a single dose of GH-gel the plasma concentrations of GH were lower than those achieved after the standard aqueous preparation. The preparation was efficacious in promoting growth and our 1st study of 6 patients suggested that GH-gel given twice a week had a growth response equal to that of the three-times a week aqueous schedule. However both schedules resulted in the frequently observed decreased growth rate during the second treatment year. Our 2nd study, attempting to ameliorate this waning effect by using the GH-gel preparation twice a week in a weight-adjusted dose during the entire second year did not resolve the problem. Thus, GH in depot gel results in more physiological plasma concentrations of GH and may be beneficial in reducing the quantity of hormone needed and the injection frequency but it does not offer a solution to the waning response to the long-term administration of GH.

Adolescent↗
PubMed1979

Inhibition of surfactant production by insulin in fetal rabbit lung slices.

Incorporation of labeled glucose and fatty acid residues into saturated phosphatidylcholine was significantly reduced in lung slices from 27.5 days of gestation fetal rabbits during 90 min incubation in the presence of 100 microU/ml insulin. When 14C-glucose was used as substrate, incorporation into both phosphatidylcholine and saturated phosphatidylcholine was reduced by insulin. This occurred despite an increase in overall glucose utilization by the lung from 11.3 +/- 3.9 to 16.3 +/- 5.2 nmole/g tissue in the presence of insulin (P less than 0.05). A decrease in incorporation of fatty acid residues into saturated phosphatidylcholine was also observed when 14C-palmitate was used as substrate, from 102 +/- 4 to 90 +/- 5 nmole palmitate/g tissue (P less than 0.01). In the presence of insulin, there were significant reductions of both substrates appearing in lysophosphatidylcholine, a precursor of saturated phosphatidylcholine. There was no significant change in incorporation of glucose residues into glycogen or lactate under these conditions.

Animals↗
PubMed1979

Enhancement of fetal lung surfactant production by aminophylline.

Antepartum administration of aminophylline to pregnant rabbits resulted in accelerated formation of phospholipids regarded to be important components of pulmonary surfactant. Increases in the tissue content and synthesis of saturated phosphatidylcholine and phosphatidylinositol were found in lung slice preparations obtained from fetuses previously treated with aminophylline. Synthesis of phospholipids was measured using labeled palmitate, oleate, and glucose as precursors. The results showed increased de novo production of these lipids, and that glucose and glycogen may serve as important precursors. There was a significant reduction in triglyceride content while free fatty acids increased suggesting increased lipolysis in the aminophylline-treated groups, but this did not measurably affect the rate of labeled palmitate incorporation into total phospholipids.

Aminophylline↗
PubMed1979

Inherited abnormal thyroid hormone-binding protein causing selective increase of total serum thyroxine.

A 9-yr-old boy is described in whom increased serum T4 concentration, increased T3 uptake, and increased free T4 index were associated with a euthyroid clinical state with normal total serum T3. T4-binding globulin (TBG), measured by RIA, was decreased. Reverse flow paper electrophoresis of serum proteins after reaction with radioactively labeled T4 demonstrated increased binding of T4 to a protein with electrophoretic mobility corresponding to albumin. Displacement of serum protein-bo-nd [125I]T4 activity by increasing concentrations of T4 revealed the presence of a low affinity, high binding capacity system with an association constant similar to that of T4-binding prealbumin. This low affinity binding protein cochromatographed with TBG on a DEAE-Sephadex column which normally separates TBG from T4-binding prealbumin. At free T4 concentrations equivalent to those present in the plasma of normal individuals, the T4 bound to free ratio is higher in the patient than in normals and the total serum T4 level is increased in the presence of normal free T4 concentrations. The relative affinity of this abnormal T4-binding protein for T3 is low compared to that of TBG. The patient's father had the same abnormal binding protein, which was not found in his mother or fraternal twin brother. These data suggest an autosomal dominant mode of inheritance of an aberration leading to synthesis of a new protein instead of normal TBG. The new protein is different from TBG in electrophoretic mobility, T4 and T3 binding, and antigenic properties.

Child↗
PubMed1978

Disproportionate growth of the lower extremities. A major determinant of short stature in Turner's syndrome.

The relationships between the height (H), sitting height (SH), and the lower segment (H-SH) were studied in a group of 21 patients with Turner's syndrome. The SH/H ratio was markedly abnormal (0.55), equivalent to that of 6-year-old normal girls. The abnormality in ratio was a result of markedly shortened lower extremities. Further, there was a significant inverse correlation between SH/H-SH ratio and height such that patients with the most shortening of their legs were the shortest. The degree of abnormality in lower segment, therefore, is a major determinant of stature in Turner's syndrome.

Adolescent↗
PubMed1978

Pharmacokinetics of flunitrazepam following single- and multiple-dose oral administration to healthy human subjects.

Healthy human subjects received single and multiple oral doses of flunitrazepam. Absorption and disposition were first order and reproducible from administration. The oral doses were virtually completely available to the liver, and elimination from the body occurred entirely via metabolism. Assuming the liver to be the sole eliminating organ, hepatic blood clearance and extraction ratio were approximately 0.235 liter/hr/kg and 0.154, respectively. Steady-state blood volume of distribution averaged 3.76 liters/kg in the single-dose studies. Terminal exponential half-lives from the single- and multiple-dose studies (different subjects) averaged 13.5 and 19.2 hr, respectively; these differences were not due to clearance changes but were entirely attributable to variations in volumes of distribution.

Administration, Oral↗
PubMed1978

Effects of cortisol and aminophylline upon survival, pulmonary mechanics, and secreted phosphatidyl choline of prematurely delivered rabbits.

Rabbits delivered at 27.0 days of gestation were studied after administration of cortisol (2 mg/kg/day), aminophylline (6.25 mg/kg/day), or sterile saline to the does on days 24-26 of gestation. Survival at 60 min was 52.9% in the aminophylline-treated group and 22.2% in the control and cortisol-treated groups with all animals being in a warm, oxygen-enriched environment and receiving frequent tactile stimulation. Lung volume at 30 cm H2O was lower in the cortisol-treated group than in the controls or aminophylline-treated group in animals surviving for 60 min (Table 2). The aminophylline-treated group retained significantly more gas at low pressures on the deflation curve (Table 2) and had significantly more phosphatidylcholine recovered in lung lavage fluid (Table 3) than the other groups. Aminophylline appears to have enhanced lung maturation better than cortisol in this experimental model.

Adenosine Monophosphate↗