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Biomedical subjects

D Sherman

Publications and source records attributed to D Sherman.

At least 127 records · Page 7Linked to original sources
PubMed1985

Perinatal outcome following physicians' strike of 1983.

Organized public medical services were profoundly disturbed during the 4 months of the physicians' strike in 1983. An unknown proportion of patients were referred to private services, but only a minority of them attended the alternative centers. The findings during the strike and the following 6 months were compared with those of the year 1982. The incidence of high-risk cases and of multiple and premature deliveries were unchanged. There was a significant rise (P less than 0.01) in the rate of cesarean sections during the strike, 10.8%, compared with 7.8% in 1982. Also, a significant reduction in instrumental deliveries and labor inductions was observed during the strike and for 4 months afterwards. There was no change in the perinatal mortality (total and corrected) or in Apgar scores. This indicates that good perinatal results were achieved despite drastic disturbances in organized perinatal care.

Apgar Score↗
PubMed1984

The neuroanatomical and neurovascular organization of normal fetal hypothalamic explants in the third cerebral ventricle of Brattleboro rats with homozygous diabetes insipidus.

This investigation has combined microangiography, immunocytochemistry, coupled with transmission and scanning electron microscopy to discuss the neuroanatomical interactions that occur in the brains of Brattleboro rats with diabetes insipidus, following stereotaxic placement of normal fetal hypothalamic fragments into the third cerebral ventricle. Following surgical placement of 17 day post-coitus hypothalamic fragments, host rats with chronic autosomal homozygous diabetes insipidus were killed and their brains were prepared for analysis. A significant degree of explants (68%) flourished and grew in the lumen of the third cerebral ventricle of recipient hosts. Explants were rapidly invaded by host vessels from two routes. Vessels arose from the underlying mantle plexus of portal capillaries which remained fenestrated in the lower one-third of the explants and developed neurovascular (neurohemal) zones. The second source of vessels arose from bed capillaries of the adjacent paraventricular nucleus and adjacent hypothalamus. In contrast to vessels arising from the contact zone, these latter vessels remained unfenestrated. Small clusters of immunocytochemically positive neurons (neurophysin positive) were seen throughout the explants. Numerous healthy magnocellular neurons harboring numerous dense core vesicles and exhibiting multiple axosomatic and axodendritic synapses were seen throughout the neuropil of explants. Axon profiles were noted to terminate upon the abluminal basal lamina of perivascular spaces surrounding fenestrated capillaries in the lower one third of explants. None of the host animals exhibited physiological return to normal parameters of urine output, drinking behavior, and/or urine osmolarity. However the growth and development of explants in the third cerebral ventricle of DI hosts coupled with the emergence of bonafide neurovascular zones supports a potential anatomical substrate for the central delivery of neuropeptide hormones in this experimental model.

Animals↗
PubMed1982

Histiocytic lymphoma and malignant angioendotheliomatosis: one disease or two?

The case history of a patient with diffuse histiocytic lymphoma and skin lesions characteristic of malignant angioendotheliomatosis is reported. The patient initially responded to aggressive chemotherapy but quickly had a relapse, CNS disease developed, and the patient died one year after diagnosis. Microscopic, ultrastructural, and surface membrane studies showed that the intravascular tumor cells were not of endothelial origin. The morphologic similarity of the malignant intravascular cells and peripheral blood cells, as well as the demonstration of surface membrane immunoglobulin on malignant blood cells suggested that, in some cases, unusual features of malignant lymphoma may be confused with malignant angioendotheliomatosis.

Diagnosis, Differential↗
PubMed1982

Effect of pentagastrin on parietal cell ultrastructure in glucagon-pretreated subjects.

The effect on parietal cells of glucagon given prior to pentagastrin is unknown. Fifteen healthy volunteers were studied during constant intravenous infusion of pentagastrin (2 micrograms/kg body weight/hr) and during pentagastrin infusion initiated 20 min after intravenous injection of 2 mg glucagon. Three types of studies were performed: Gastric mucosal biopsies were obtained with a Quinton instrument. Electron micrographs of 320 parietal cells were analyzed by the Loud quantitative method, and intragastric pH (pH probe), or gastric potential difference (PD) were recorded continuously. Pentagastrin infusion produced a significant increase in canalicular and simultaneous reduction of tubulovesicular membrane area of parietal cells. Glucagon pretreatment did not inhibit canalicular and tubulovesicular membrane reaction to pentagastrin; unexpectedly this reaction was significantly greater when compared to that after pentagastrin alone. Initiation of pentagastrin infusion in subjects pretreated with glucagon produced a greater absolute value drop in gastric PD (23 +/- 2 mV) and an earlier drop in intragastric pH (3 min) than in subjects receiving pentagastrin infusion alone (13 +/- 1 mV and 10 min, respectively). In conclusion, at the doses studied, glucagon pretreatment increases parietal cell canalicular reaction to pentagastrin.

Adult↗
PubMed1982

A new semiautomatic method for quantitative static and dynamic bone histology.

A new semiautomatic technique combining advantages of the manual and fully automatic methods is described for obtaining quantitative static and dynamic histologic data of bone. The hardware consists of a photomicroscope, digitizing platen, digitizer, plotter/printer, floppy disc drive, and computer. The microscope is equipped with a drawing tube through which the image of the digitizing platen is projected over the optical field. The investigator selects and traces all histologic structures to be measured by moving a cursor on the digitizing platen which is visible by its projection over the histologic field. The results on accuracy and static and dynamic precision of this method show that static and dynamic parameters of bone are obtained with a degree of error (less than 20%) well within the acceptable range for biologic measurements. Comparison of this method with the grid technique according to Merz and Schenck showed that for almost all micromorphometric parameters comparable absolute data are obtained. Due to the higher precision of our method, however, the number of optical fields evaluated in obtaining these comparable data could be reduced to 25% of the number of fields evaluated by the Merz and Schenck technique. The time requirements for quantitative evaluation of a histologic slide of bone by our technique are 40-50 min; 20-25 min is needed for quantitative evaluation of osteocytes.

Bone Resorption↗
PubMed1982

Quantitative bone histology in 84 normal American subjects. Micromorphometric analysis and evaluation of variance in iliac bone.

Quantitative bone histology was done in undecalcified sections of iliac crest bone specimens obtained from 84 normal American individuals. Samples were obtained within 12 h after death in a vertical and horizontal manner from both the right and left iliac crests. In addition to the determination of normal values of micromophometric parameters of bone in these healthy American subjects, the following studies were carried out: (a) comparison of variance of micromorphometric parameters of bone obtained from the right versus left iliac bone (40 pairs), (b) comparison of micromorphometric parameters of bone obtained in a vertical versus horizontal manner (12 pairs), (c) evaluation of variance with increasing distance from the compact zone in bone samples obtained in a vertical manner (44 pairs), (d) analysis of variation between bone samples obtained more anteriorly versus posteriorly along the iliac crest (N = 40), (e) comparison of differences in micromorphometric parameters obtained from age-matched men versus premenopausal women (N = 12), and (f) plotting of histograms for assessment of distribution of micromorphometric parameters. The results show that histomorphometric data of bone cannot be easily compared when different techniques are employed for obtaining bone samples. Sampling variations are kept smaller when bone specimens are obtained in a vertical manner. Anterior/posterior variation does not cause major sampling error. If ranges of variation are taken into account, quantitative bone histology is a valuable tool for assessment of bone structure and bone cells.

Adolescent↗
PubMed1982

Improved fertility following ectopic pregnancy.

The reproductive performance subsequent to operative removal of ectopic pregnancy was examined in 154 women. They represent 64% of 242 women admitted for ectopic pregnancy between 1969 and 1979. The follow-up period averaged 4.2 years. The patients at risk had a conception rate of 81%, with a repeat ectopic pregnancy incidence of 7.8%, and 65% had at least one live birth. Postoperative infertility was significantly associated with (1) previous sterility, (2) coexistent periadnexal adhesions and/or tubual disease, (3) rupture of the ectopic pregnancy, and (4) older age. A statistically significant advantage of conservative over radical treatment, as regards future fertility, was demonstrated only in 53 patients with either history or findings suggestive of previously impaired fertility. Early, prerupture diagnosis and treatment, coupled with conservative and restorative measures, might account for the improved reproductive performance.

Adolescent↗
PubMed1982

Conservative surgery for tubal pregnancy.

Fifty-seven conservative surgical procedures for unruptured tubal pregnancy were performed on 54 patients. Salpingotomy was performed in 44 cases and fimbrial expression of the ectopic gestation was performed in 13 cases. In this patient group, 80% of the patients (39 of 49) experienced intrauterine pregnancy following surgery and 71% (35 of 49) had a live birth. The recurrence rate of tubal pregnancy was 12%. Ninety percent of the patients with a normal contralateral tube had an intrauterine pregnancy following surgery and a 7% recurrence rate of tubal pregnancy, a ratio of 1:15. It is suggested that the indications for the conservative surgical management in patients with unruptured tubal pregnancy should be broadened to all patients interested in future pregnancies and should also be considered in those cases with normal contralateral tube.

Fallopian Tubes↗
PubMed1982

Effects of long-term infusion of physiologic doses of 1-34 PTH on bone.

It has been suggested that small doses of PTH could exert an anabolic effect on bone and could be beneficial in the management of bone diseases secondary to low bone formation. The effects of 20 wk of continuous infusion of 0.05 U.kg-1.h-1 of 1-34 PTH on cellular, structural, and dynamic parameters of bone were studied in inbred beagles. This physiologic or near physiologic dose of PTH caused a small but significant rise in the concentration of serum calcium and a significant increment in the plasma concentration of 1,25(OH)2D. In addition, the sustained infusion of PTH was associated with a significant increment in volume and surface density of osteoid without a change in bone mass. Mineralization of osteoid was not altered, as evidenced by normal double tetracycline uptake and normal osteoid seam thickness. The enhanced osteoid production was not due to augmented bone formation by individual osteoblasts or basic remodeling units but rather to increased activation frequency resulting in an increased number of remodeling units. There was also augmented bone resorption at the tissue level. The data indicate that small doses of PTH do not have an anabolic effect on the skeleton because they are not associated with increased net bone formation. Rather, PTH administration is associated with an increase in coupled bone turnover.

Animals↗
PubMed1982

Effect of secretin on gastric parietal cell ultrastructure in man.

The effect of secretin on parietal cell ultrastructure and on gastric mucosal potential difference have not been reported. In five healthy subjects, we studied the effect of intravenous injection of 2 clinical units per kg. of secretin on parietal cell canalicular and tubulovesicular membrane areas. In addition, we studied the effect of secretin on serum secretin levels and gastric mucosal potential difference. Biopsies of gastric mucosa for light and electron microscopy were obtained prior to and 15 and 30 minutes after secretin injection. Electron micrographs of 140 parietal cells were analyzed by the Loud quantitative method. Fifteen minutes following secretin administration, parietal cell canalicular membrane area decreased from a basal value of 4.37 +/- 0.43 per cent to 3.17 +/- 0.28 per cent (p less than 0.01). The number and length of microvilli also significantly decreased. Tubulovesicular membrane area increased from 9.32 +/- 0.7 per cent to 9.74 +/- 0.6 per cent (p greater than 0.05). The effect of secretin on canalicular membrane area was short lived, with recovery to nearly basal level at 30 minutes. Nuclear membrane area did not change at 15 and 30 minutes after secretin. After injection, serum secretin increased from a mean basal value of 15 to 2800 pg. per ml. at 15 minutes, falling to 130 pg. per ml. at 30 minutes. Gastric potential difference following secretin injection rose from -43 +/- 2 mv. to -54 +/- 2 mv. (p less than 0.01) within 10 minutes. In conclusion, a pharmacologic dose of secretin alters gastric parietal cell ultrastructure and causes significant elevation of gastric mucosal potential difference.

Adult↗
PubMed1981

Vitamin D metabolites and calcium metabolism in patients with nephrotic syndrome and normal renal function.

Patients with nephrotic syndrome (NS) lose 25-hydroxyvitamin D3 (25OHD3) in the urine and have low blood levels of this metabolite. This abnormality may be responsible for the hypocalcemia, i.e. low ionized calcium. The mechanism of the hypocalcemia is not evident. It is possible that the low value of 25OHD results in low blood levels of other vitamin D metabolites, such as 1,25-dihydroxyvitamin D [1,25-(OH)2D] and 24,25-(OH)2D3; a deficiency of these compounds may cause defective intestinal absorption of calcium (alpha) and resistance to the calcemic action of parathyroid hormone (PTH), resulting in hypocalcemia. Studies were performed in 12 patients with NS and normal renal function to evaluate these questions. Blood levels of 25OHD, 1,25-(OH)2D, and 24,25-(OH)2D were all significantly (P < 0.01) lower in NS (4.0 +/- 0.8 ng/ml, 7.0 +/- 2.3 pg/ml, 1.8 +/- 0.2 ng/ml, respectively) compared to normal subjects (37.0 +/- 1.5 ng/ml, 37.0 +/- 1.2 pg/ml, and 3.4 +/- 0.2 ng/ml). Both alpha (0.21 +/- 0.2 vs. 0.27 +/- 0.1; P < 0.05) and the calcemic response to PTH (0.50 +/- 0.1 vs. 1.35 +/- 0.16 mg/dl; P < 0.01) in NS subjects were significantly lower than normal. The data indicate that 1) a deficient state of all of these vitamin D metabolites exists in patients with NS and normal renal function, 2) this abnormality underlies the defect in alpha and the resistance to the calcemic response to PTH, and all participate in the genesis of the hypocalcemia, 3) secondary hyperparathyroidism develops, and 4) both vitamin D deficiency and elevated blood levels of PTH are responsible for the bone lesions in these patients.

24,25-Dihydroxyvitamin D 3↗
PubMed1981

The transportable recompression rescue chamber as an alternative to delayed treatment in serious diving accidents.

This report summarizes experience in the use of a Transportable Recompression Rescue Chamber (TRRC) for one man in the rapid initiation of treatment and evacuation in severe scuba diving accidents. An evacuation system is described which incorporates the centralized management of all diving accidents and standardized TRRCs capable of interlocking under pressure with the stationary medical chamber. Oxygen breathing capability in the TRRC allows the use of up-to-date U.S. Navy oxygen treatment tables. Included are 19 cases of Type II decompression sickness and pulmonary barotrauma with neurological manifestations, most of which occurred at remote diving sites with no nearby walk-in chambers. Case analysis includes distance and means of evacuation, delay in initiating therapy, time spent in TRRC, and initial and final outcome. Together, TRRCs and airborne evacuation to a stationary medical chamber insures a minimal delay between the onset of symptoms and the start of recompression therapy. The use of the TRRC is a prime factor in minimizing delay. No complications associated with the use of TRRCs have been encountered. Ideally, evacuation should be made in a pressurized two-compartment (for a victim and an attendant) chamber. However, if this is not available we strongly advocate the use of one-man pressurized TRRCs over unpressurized evacuation.

Barotrauma↗
PubMed1981

Chokes--favorable response to delayed recompression therapy: a case report.

The pulmonary manifestations of decompression sickness have been attributed to various mechanisms, all of which invoke bubble formation and presence in the lung as the cause of symptoms. A case of persistent "chokes" syndrome, which responded to recompression of 72 h after presentation, is described. The possible physiological mechanisms and the late response to therapy is discussed.

Adult↗