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Biomedical subjects

S Feldman

Publications and source records attributed to S Feldman.

At least 19 recordsLinked to original sources
PubMed1992

Corticosterone implants in the paraventricular nucleus inhibit ACTH and corticosterone responses and the release of corticotropin-releasing factor following neural stimuli.

Experiments were conducted on the possible role of corticosterone (CS), at the level of the paraventricular nucleus of the hypothalamus (PVN) and dorsal hippocampus (D.HIPP), in the negative feedback effects following neural stimuli. In rats with bilateral PVN cholesterol (CHO) implants, acoustic and photic stimuli caused a significant rise in serum CS and ACTH and depletion of median eminence (ME) CRF-41 content. CS PVN implants have prevented the rise in serum CS, ACTH and ME CRF-41 depletion. Bilateral CHO or CS implants in the D.HIPP did not modify the responses of the hypothalamo-pituitary-adrenal axis to the above neural stimuli. In PVN CS-implanted rats, i.v. injection of CRF-41 increased serum CS similar to that observed in PVN CHO-implanted animals. These data are discussed in view of previous experiments on corticosteroid implants in the brain. It is concluded that CS PVN implants, by acting possibly via type II hypothalamic receptors, have prevented the release of ME CRF-41 following neural stimuli and consequently the secretion of ACTH and CS.

Acoustic Stimulation↗
PubMed1992

Head injuries after serious bicycle accidents.

Between 1987 and 1988 there were 47 serious or fatal injuries among bicycle riders in the city of Tel Aviv-Yafo (Serious injury was defined as being hospitalized for at least 24 hours). Collisions with vehicles, mostly cars, were responsible for about 80% of these cases. Two-thirds of the accidents occurred in adults aged 20 and over. We were able to trace the records of 24 of the 47 who were injured. Head trauma was the most common form of severe injury, occurring in 11 of the 24 cases. Two of the 11 died instantly and one died after 14 days of hospitalization, all from severe brain damage. Eight suffered severe head trauma, 7 of which had brain injury and 2 of the 7 were left with severe residual brain damage. In view of the efficacy of bicycle helmets in preventing head trauma there is a great need to expand their use among bicyclists in Israel.

Accidents, Traffic↗
PubMed1992

Hepatic angiosarcoma.

A patient with hepatic angiosarcoma is described. The significant aspects of this malignancy are delineated. This tumor constitutes only 2% of all primary tumors of the liver. The association with exposure to vinyl chloride and other carcinogens is reviewed. Diagnostic and therapeutic modalities are discussed.

Adult↗
PubMed1992

Comparison of acellular (B type) and whole-cell pertussis-component diphtheria-tetanus-pertussis vaccines as the first booster immunization in 15- to 24-month-old children.

We compared an acellular (B type) pertussis-component diphtheria-tetanus-pertussis (DTP-Ac) vaccine containing equal amounts of filamentous hemagglutinin and lymphocytosis-promoting factor with a conventional whole-cell vaccine as the first booster immunization in 162 healthy children 15 to 24 months of age. Fewer local reactions (e.g., erythema, swelling, and tenderness at the injection site) were seen in DTP-Ac vaccine recipients during the first 48 hours of observation. This group also had fewer episodes of fever (> or = 38 degrees C) and other systemic reactions (e.g., irritability, drowsiness, and anorexia). Overall, 57% of the DTP-Ac vaccine recipients had no obvious adverse reactions, in contrast to 5% in the comparison group. At 4 to 8 weeks after vaccination, serum antibody responses to filamentous hemagglutinin and lymphocytosis-promoting factor were greater in recipients of the acellular vaccine as determined by an enzyme-linked immunosorbent assay. We conclude that this B-type acellular vaccine is both immunogenic and much less likely to cause an adverse reaction than a currently licensed whole-cell vaccine, and is suitable for routine booster immunizing doses to protect against pertussis.

Analysis of Variance↗
PubMed1992

Acyclovir treatment of varicella in otherwise healthy adolescents. The Collaborative Acyclovir Varicella Study Group.

STUDY OBJECTIVE: To determine whether orally administered acyclovir is of therapeutic benefit for varicella in otherwise healthy adolescents, and to compare the severity of the disease in adolescents with that in younger children. DESIGN: Multicenter, randomized, placebo-controlled, double-blind trial. SETTING: Patients' homes and university hospital clinics. PATIENTS: Sixty-eight adolescents between 13 and 18 years of age with varicella entered the study. Of the 62 adolescents with laboratory-confirmed varicella who were included in the final analysis, 31 received acyclovir and 31 received placebo. INTERVENTIONS: Placebo or an 800 mg acyclovir tablet was given orally four times daily for 5 days, beginning within 24 hours of onset of rash. MEASUREMENTS AND MAIN RESULTS: Acyclovir recipients had significant reductions in times to cessation of new lesion formation (p less than 0.001), maximum number of lesions (p = 0.019), and defervescence (p = 0.045). Mean constitutional illness score was significantly reduced on day 4 (0.5 vs 1.5, p = 0.05), as was the mean number of residual hypopigmented lesions present on 28-day follow-up examination (22.7 vs 92.7, p = 0.018). Two complications, both bacterial superinfections, occurred in placebo recipients. Adverse experiences and varicella-zoster virus antibody titers measured 28 days after enrollment were similar in both treatment groups. Comparison of placebo recipients with children 2 to 12 years of age participating in a companion study indicated that varicella is more severe in adolescents: mean maximum total lesions (421 vs 347, p = 0.003), mean maximum constitutional illness score (3.1 vs 2.2, p = 0.032), and mean number of residual lesions (92.7 vs 33.2, p = 0.01) were all greater in the adolescent population. CONCLUSIONS: Oral acyclovir therapy is safe and effective for treatment of varicella in otherwise healthy adolescents; this may be an appropriate subgroup for treatment with antiviral drugs because the disease is more severe in them than in younger children.

Acyclovir↗
PubMed1992

Seroprevalence of human immunodeficiency virus among adolescent attendees of Mississippi sexually transmitted disease clinics: a rural epidemic.

Human immunodeficiency virus (HIV) infection among adolescents is causing increasing concern, and teenagers attending sexually transmitted disease (STD) clinics run a high risk of contracting it. To determine the status of HIV infection in a Mississippi adolescent population, we evaluated seroprevalence rates for adolescents attending Mississippi State Department of Health STD clinics from 1988 to 1990. During this 2-year period, 9855 adolescents (aged 13 to 20 years) attended STD clinics, and HIV antibody was confirmed in 39 (seroprevalence rate 4.0/1000; 95% confidence interval [CI] 2.7 to 5.2). Seropositive rates were almost equal for male and female subjects (4.1/1000 and 3.8/1000, respectively), suggesting predominantly heterosexual transmission. Rates among blacks were 3.5 times higher than among whites. Adolescents with HIV infection were identified throughout the state, irrespective of urban centers. Rates among the smallest counties (ie, population less than 25,000) were not significantly different from those of the largest counties (ie, population greater than 100,000). Mississippi's rank in the top 10 states for other STDs and the state's high teenage pregnancy rate make it an epicenter of the HIV epidemic among adolescents.

Adolescent↗
PubMed1992

Pipecuronium versus high dose vecuronium. I. A comparison of speed of onset and cumulation during isoflurane anaesthesia.

The onset time and tendency to cumulation of pipecuronium and high-dose vecuronium were studied during nitrous oxide anaesthesia supplemented with isoflurane. Pipecuronium 0.06 mg.kg-1 had a similar duration of action to vecuronium 0.015 mg.kg-1 (42 vs 49 min). Patients who received vecuronium had a shorter onset time of neuromuscular blockade (p less than 0.01). The use of pipecuronium was associated with marked cumulation.

Adult↗
PubMed1992

Pipecuronium versus high dose vecuronium. II. A comparison of speed of onset and cumulation during propofol anaesthesia.

The onset time and tendency to cumulation of pipecuronium and high-dose vecuronium were compared during nitrous oxide anaesthesia supplemented with a propofol infusion. Pipecuronium 0.06 mg.kg-1 had a similar duration of action to vecuronium 0.2 mg.kg-1 (49 vs 43). Patients who received vecuronium had a shorter onset time of neuromuscular blockade (p less than 0.01). Neither pipecuronium nor vecuronium showed marked cumulation.

Adult↗
PubMed1992

Pacemaker dependency after coronary artery bypass.

A retrospective study was carried out on 36 patients (33 males and 3 females) to determine the incidence of VVI pacemaker dependency following coronary artery bypass surgery. Pacemaker dependency was defined as the presence of pacemaker activity when pacing rate was programmed at 50 beats/min and/or when no hemodynamic adequate rhythm was present during pulse generator replacement. The patients were divided into two groups: (group I) 26 patients with complete atrioventricular (AV) block developing in the early postoperative period. In most of them a pacemaker was implanted up to 3 weeks following surgery (range 2 days to 1 year); (group II) ten patients in whom the indication for pacemaker implantation was sick sinus syndrome with sinus arrest and/or tachy-bradycardia. These patients underwent pacemaker implantation at varying periods of time following surgery (range 12 days to 4 years). Unipolar endocardial leads with VVI programmable pacemakers were implanted in all patients included in this study. Mean follow-up time was 3 years. In group I the pacemaker dependency rate was 65%, whereas in group II it was 30% throughout the follow-up period. It is concluded that the low incidence of pacemaker dependency in patients who undergo pacemaker implantation after coronary bypass surgery necessitates frequent evaluation in the nondependent patient, in order to reassess the need for the pacemaker before pulse generator replacement. Such reassessment should probably include prolonged ambulatory monitoring as well as invasive evaluation of the conduction system, if avoidance of pulse generator replacement is considered.

Aged↗
PubMed1992

Fertility in women with late-onset adrenal hyperplasia due to 21-hydroxylase deficiency.

Fertility was evaluated in 53 female patients with late-onset adrenal hyperplasia (LAH) due to 21-hydroxylase deficiency. The majority of patients (n = 33) were seen for isolated postpubertal hirsutism, 9 patients consulted for sterility, and 11 for irregular menstrual cycles. At the time of diagnosis, the ages of patients ranged from 15-40 yr (mean +/- SD, 24.6 +/- 5.2). No patient had major signs of virilization. The plasma 17-hydroxyprogesterone level was higher than normal in all patients (26.8 +/- 18.9 nmol/L; range, 3.4-139.4) and dramatically increased to 140.1 +/- 80.6 nmol/L (range, 35.2-324.2) after ACTH treatment. Plasma androgen levels were high (testosterone, 3.25 +/- 2.03 nmol/L; delta 4-androstenedione, 13.65 +/- 5.60 nmol/L). Plasma basal and LHRH-stimulated values were normal for FSH and high for LH. Basal and TRH-stimulated plasma PRL levels were normal. Among these 53 LAH patients, only 20 desired a pregnancy. These had a total of 38 pregnancies. Ten patients became pregnant before the diagnosis of LAH and without any treatment; they had a total of 18 pregnancies, 12 of which were successful. Moreover, 19 normal pregnancies without any spontaneous abortion were carried to term by 14 of 16 hydrocortisone-treated patients. One patient needed the association of one cure of clomiphene citrate. Hypofertility in LAH patients seems, therefore, to be relative. Its mechanism is hormonal, with anovulation or dysovulation, due to the continuous steroid feedback of adrenal origin on the hypothalamo-pituitary axis. Hydrocortisone is the appropriate treatment in most cases, reducing adrenal androgen overproduction and relieving hypothalamic-pituitary gonadotropin function, thereby making possible cyclic ovarian activity and ovulations.

17-alpha-Hydroxyprogesterone↗
PubMed1992

Relative importance of urinary sulfate and net acid excretion as determinants of calciuria in normal subjects.

In normal subjects fed western-mixed diets, in the fasting state, 39.6% of the variance of calciuria is accounted for by net acid excretion and 4% by sulfaturia. In the postprandial period, net acid accounts for 6.9% and sulfaturia for 11.8% of the variance of calciuria. As expected, after a load of ammonium chloride, net acid excretion exceeded the importance of sulfaturia (36.2% vs. 8.4%) and the opposite was observed after DL-methionine load (1.5% and 46.2%). A group of normal subjects fed vegetarian diets was also investigated. The excretion of the three variables measured were significantly reduced in this group when compared with that of the former group. In the fasting state the variance of calciuria was accounted mainly by net acid excretion (85.7%). In the postprandial state net acid (4.9%) and sulfate (2.2%) had much less importance as determinants of calciuria. It is concluded that in spite of their metabolic relationship, net acid and sulfate excretions are independent determinants of calciuria. The relative importance of each variable changes as a function of metabolic circumstances.

Acids↗
PubMed1992

Adenocarcinoma in situ of the uterine cervix.

OBJECTIVE: To assess the diagnostic accuracy of cervical conization in women with adenocarcinoma in situ and to determine whether a select group of women could be managed by conization alone without hysterectomy. METHODS: We retrospectively reviewed 40 cases of cervical adenocarcinoma in situ diagnosed on cervical conization. RESULTS: Cervical conization revealed adenocarcinoma in situ alone in 15 women. Twenty-five women had adenocarcinoma in situ coexisting with squamous dysplasia (23) or microinvasive squamous cell carcinoma (two). Twenty-two women underwent hysterectomy after cone biopsy. Adenocarcinoma in situ was detected in the hysterectomy specimen in one of 12 women with uninvolved cone margins, versus seven of ten women with involved margins (P = .006); two of these seven women also had foci of invasive adenocarcinoma in the hysterectomy specimen. Conization was the only treatment for 18 selected women with adenocarcinoma in situ and uninvolved margins; all were relapse-free after a median interval of 3 years (range 1.5-5). CONCLUSIONS: Women with cervical adenocarcinoma in situ diagnosed by conization who have positive margins are at high risk of residual adenocarcinoma in situ and moderate risk of occult invasive adenocarcinoma; expectant management is not warranted. However, a cone biopsy with uninvolved margins can reliably guide subsequent therapy. Selected young women who desire preservation of fertility and have uninvolved margins probably can be managed by conization alone, but further study is required to establish the safety of this approach.

Adenocarcinoma↗
PubMed1991

Effect of 6-hydroxydopamine and 5,7-dihydroxytryptamine on tissue uptake and cell nuclear retention of corticosterone in the rat hypothalamus.

Previous studies have shown that norepinephrine and serotonin can modulate the glucocorticoid (GC) binding capacity in the hippocampus. The aim of the present study was to evaluate the role of these neurotransmitters in regulating GC receptors in the hypothalamus. Injection of the neurotoxin 6-hydroxydopamine (6-OHDA) into the ventral noradrenergic bundle (VNAB) and 5,7-dihydroxytryptamine (5,7-DHT) into the raphe nuclei caused a marked depletion in norepinephrine and serotonin, respectively, in the paraventricular nucleus (PVN) and mediobasal hypothalamus (MBH). The injection of these neurotoxins did not change the basal levels of ACTH and corticosterone. Injection of 6-OHDA into the VNAB caused a significant reduction in the cell nuclear binding of corticosterone in the PVN but not in the MBH. Conversely, injection of 5,7-DHT into the raphe nuclei caused a significant reduction in cell nuclear binding of corticosterone in the MBH but did not affect binding in the PVN. These results demonstrate that at least part of the nuclear corticosteroid receptors in the PVN and MBH are differentially regulated by the noradrenergic and serotonergic systems.

5,7-Dihydroxytryptamine↗
PubMed1991

A controlled trial of acyclovir for chickenpox in normal children.

BACKGROUND: Chickenpox, the primary infection caused by the varicella-zoster virus, affects more than 3 million children a year in the United States. Although usually self-limited, chickenpox can cause prolonged discomfort and is associated with infrequent but serious complications. METHODS: To evaluate the effectiveness of acyclovir for the treatment of chickenpox, we conducted a multicenter, double-blind, placebo-controlled study involving 815 healthy children 2 to 12 years old who contracted chickenpox. Treatment with acyclovir was begun within the first 24 hours of rash and was administered by the oral route in a dose of 20 mg per kilogram of body weight four times daily for five days. RESULTS: The children treated with acyclovir had fewer varicella lesions than those given placebo (mean number, 294 vs 347; P less than 0.001), and a smaller proportion of them had more than 500 lesions (21 percent, as compared with 38 percent with placebo; P less than 0.001). In over 95 percent of the recipients of acyclovir no new lesions formed after day 3, whereas new lesions were forming in 20 percent of the placebo recipients on day 6 or later. The recipients of acyclovir also had accelerated progression to the crusted and healed stages, less itching, and fewer residual lesions after 28 days. In the children treated with acyclovir the duration of fever and constitutional symptoms was limited to three to four days, whereas in 20 percent of the children given placebo illness lasted more than four days. There was no significant difference between groups in the distribution of 11 disease complications (10 bacterial skin infections and 1 case of transient cerebellar ataxia). Acyclovir was well tolerated, and there was no significant difference between groups in the titers of antibodies against varicella-zoster virus. CONCLUSIONS: Acyclovir is a safe treatment that reduces the duration and severity of chickenpox in normal children when therapy is initiated during the first 24 hours of rash. Whether treatment with acyclovir can reduce the rare, serious complications of chickenpox remains uncertain.

Acyclovir↗
PubMed1991

Effect of hypothalamic norepinephrine depletion on median eminence CRF-41 content and serum ACTH in control and adrenalectomized rats.

In this study we examined the role of the noradrenergic innervation of the hypothalamus on the adrenalectomy-induced changes in median eminence (ME) CRF-41 and serum ACTH. 6-Hydroxydopamine (6-OHDA), the catecholaminergic neurotoxin, or vehicle was injected into the ventral noradrenergic bundle of male rats. One week later animals underwent adrenalectomy or sham operation and were sacrificed 18 or 120 h later. In sham-operated rats 6-OHDA did not affect ME CRF-41 content or serum ACTH. In vehicle-injected adrenalectomized rats ACTH was increased approximately 3-fold at 18 h and almost 6-fold at 120 h. At 18 h CRF-41 content was markedly depleted (reduced approximately 20-fold) but by 120 h CRF-41 content had partially recovered and was about 70% of control animals. In adrenalectomized animals, 6-OHDA lesions caused a complete inhibition of the increase in serum ACTH both at 18 h and at 120 h. Pretreatment with 6-OHDA partially attenuated the drastic reduction in ME CRF-41 content following adrenalectomy at 18 h. However, at 120 h, the neurotoxin prevented the recovery of CRF-41 following adrenalectomy. These results suggest that intact norepinephrine innervation to the hypothalamus is necessary for the increased production of ACTH following adrenalectomy and that its interruption interferes with both the adrenalectomy-induced ME CRF-41 reduction and subsequent recovery.

Adrenalectomy↗