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Biomedical subjects

M Hirsch

Publications and source records attributed to M Hirsch.

At least 91 records · Page 5Linked to original sources
PubMed1989

Filipin-induced deformations in plasma membranes of cultured bovine corneal endothelial cells with incomplete belts of tight junctions.

Complete belts of intact tight junctions are thought to act as barriers to the movement of cholesterol in the plane of the plasma membrane. As cholesterol can be revealed by filipin-induced membrane deformations on freeze-fracture images, we studied the distribution of these deformation in cultured bovine corneal endothelial cells with incomplete belts of tight junctions. While the extent of filipin-induced deformations differed between individual cells, there is a homogeneous distribution of filipin-induced deformations on both sides of the incomplete junctional belt of endothelial cells. Our results suggest that cultured endothelial cells do not polarize cholesterol, possibly because of the incomplete tight-junctional barrier.

Animals↗
PubMed1989

A phase II study of the efficacy of diamminedichloroplatinum (cisplatin) for the control of locally recurrent and intransit malignant melanoma of the extremities using tourniquet outflow-occlusion techniques.

A phase II trial was conducted with 15 patients (mean age of 65.7 years) with locally recurrent or intransit melanoma of the extremities. After total outflow occlusion with pneumatic tourniquet, the cell-cycle nonspecific anti-neoplastic agent cis-diamminedicholoroplatinum (CDDP) was infused intra-arterially in a mean dose of 26.7 mg/m2 per infusion (2.6 infusions per patient). The aim of this study was to determine the efficacy of CDDP infusion for control of intransit and recurrent melanoma of the extremities. Three to four weeks postinfusion, all visible residual disease was resected. Partial remissions were observed in ten patients (67%); five patients achieved stable disease status. No patient had complete regression of disease. At an average follow-up interval of 18.3 months (range 4-44 months), the mean local/regional disease-free survival was 14.8 months. Eighty per cent of patients (twelve of 15) had local/regional control of disease at an average follow-up of 14.8 months after CDDP infusion and surgical resection. Of five melanoma-related deaths, three patients had had no local/regional recurrence at the time of their demise. Three compartment syndromes resulted as a complication of the infusional therapy and occurred within 1-3 days of the treatment. In vitro growth of melanoma from lymph nodes draining the infused area was seen in all subjects studied. Outgrowth from tumor within the tourniquet infusion area was observed in two patients, both of whom experienced recurrences clinically at 24-months' postinfusion. Pharmacokinetic data of total CDDP concentrations from tissue and blood (n = 4) were available from pretreatment to 1 hour post-therapy. Biopsy data from patients pre- and post-treatment suggest substantial tumor uptake of CDDP as compared to local or distal normal skin, with minimal CDDP loss to the systemic circulation. Pharmacologic and clinical data of this phase II trial suggest that intraarterial infusion with tourniquet outflow-occlusion augments tumor tissue levels of CDDP within the infused extremity and enhances local control of high-risk and intransit disease.

Adult↗
PubMed1989

[Psychogenic pain as a representation of the maternal object].

Since Freud, psychoanalysis has approached psychogenic pain from two points of view: conversion, and narcissistic hurt through loss of an object (pain of separation). In an early developmental phase concerning the first differentiation of self, body-self and external objects, representatives of physical and psychical pain as well as representatives of frustrating experiences with external objects (emotional deprivation, overstimulation) are able to take the place of each other reciprocally. This means, as Deutsch (1959) has elaborated, the extension of the concept of conversion to pregenital stages and its connection with object-relation-theories. The author suggests an idea of a two phase conversion, by which the primarily acquired defence of conversion is followed by later traumatization, which introduces subsequent conflicts of later developmental stages, for example oedipal ones. In the case of psychogenic pain, where physical and sexual abuse as well as the inherent guilt dynamics are frequently found, they can be integrated by using this hypothetical model. The relation to the conceptualizations of archaic hysterization (McDougall) and secondary hysterization (Mentzos) respectively symbolization (Engel) is discussed; case studies are illustrating the theoretical conception.

Humans↗
PubMed1989

[The body and food as objects in anorexia and bulimia].

In this paper the function of food and of the own body in anorexia and bulimia is understood as representations of good and bad mother objects. In anorexia nervosa the body in the state of underweight is the good mother-object ("not-mother"), the too heavy body is the bad mother-object ("like mother"). In bulimia the wish for incorporation of a good object (food before binging) and the following panic of the fusion with a bad object (food after eating) is acted out. Body and food, substituting mother objects, are manageable, the illusion of controlling self-object-boundaries is maintained. Thus anorexia and bulimia are understood as an attempt to cope with fear of fusion as well as of separation, which is revived in adolescence.

Adolescent↗
PubMed1988

Direct stimulatory effect of calcitonin on [3H]5-hydroxytryptamine release from the rat spinal cord.

The in vitro effects of porcine, salmon and human calcitonin on the K+-evoked overflow of [Met5]enkephalin, substance P and [3H]5-HT (previously taken up) were investigated in superfusion experiments with spinal cord slices. Porcine and salmon calcitonin did not affect the release of [Met5]enkephalin and substance P but enhanced that of [3H]5-HT. In contrast, human calcitonin was inactive. The stimulatory effect of porcine and salmon calcitonin on K+-evoked [3H]5-HT overflow was found with slices from the dorsal or the ventral half of the lumbar enlargement but not with hippocampal or hypothalamic slices. The calcitonin effect on [3H]5-HT outflow persisted in the absence of extracellular Ca2+ but was totally suppressed by 5-HT uptake inhibitors such as citalopram and chlorimipramine and by the 5-HT-releasing agent, p-chloroamphetamine. Direct investigation of the possible action of porcine calcitonin on [3H]5-HT uptake and release demonstrated that the enhanced [3H]5-HT overflow resulted from a p-chloramphetamine-like 5-HT-releasing effect of the hormone at the spinal level. This action might be involved in the potent analgesic effect of intrathecal calcitonin.

Animals↗
PubMed1988

Orthogonal arrays of particles in non-pigmented cells of rat ciliary epithelium: relation to distribution of filipin- and digitonin-induced alterations of the basolateral membrane.

It has been suggested that orthogonal arrays of particles may increase the rigidity of plasma membrane, as does cholesterol. Therefore, using freeze-fractured non-pigmented ciliary epithelium, the distribution of such arrays was compared to the distribution of membrane deformations induced by the sterol-probes filipin and digitonin in different domains of the basolateral plasma membrane. The distribution of orthogonal arrays of particles was homogeneous between different regions of the basolateral membrane of the non-pigmented ciliary epithelium, while the number of filipin-induced alterations was nearly 4 times higher in the membrane domains not in contact with the basal lamina than in domains in contact with it. Contrary to the homogeneous distribution of arrays, digitonin-induced deformations also differed markedly in these two basolateral membrane domains. Considering that a marked positive response to sterol probes implies a high sterol content, we conclude that orthogonal arrays of particles can occur in plasma membrane regions well-provided with cholesterol and not in direct contact with the basal lamina. Other possible roles of these arrays are discussed.

Animals↗
PubMed1988

Computerized tomography in the diagnosis and treatment of orbital cellulitis.

Acute sinusitis remains the major cause of orbital cellulitis in children, despite the extensive use of antibiotics. Staging of orbital cellulitis on the basis of clinical signs is difficult but is easily achieved by computerized tomography. The CT findings in a series of 9 children with orbital cellulitis in different stages are reported. The information obtained by CT contributes to the selection of an adequate surgical approach, if a therapeutic trial with antibiotics fails.

Acute Disease↗
PubMed1988

Superior vena cava syndrome: presenting symptom of silent otitis media.

An extensive lateral sinus thrombosis secondary to silent otitis media, in a patient with a nephrotic syndrome, is presented. The thrombotic process progressed asymptomatically until the occlusion of the superior vena cava. Removal of the intractable pathology within the mastoid and administration of appropriate antibiotic therapy, prevented the further propagation of the life-threatening condition.

Humans↗
PubMed1988

Enterolithiasis.

We have seen two cases of enterolithiasis in middle-aged Bedouin women. In the first, the cause was prestenotic saccular dilatation from a postoperative stricture of the terminal ileum. In the second, stones formed in congenital diverticula in the terminal ileum and cecum. In both patients, the diagnosis was established by small-bowel enema.

Adult↗
PubMed1988

Estimation of body fat from ultrasound measures of subcutaneous fat and circumferences in obese women.

Body density and body fat are commonly estimated from measures of subcutaneous adipose tissue taken with skinfold calipers at specific body sites. In obese individuals, factors such as compression and inability to palpate tissues hinder the accurate measurement of skinfolds. Thus, the use of skinfold caliper measurements may yield spurious body density values. Previous research indicated that in obese persons, subcutaneous adipose tissue thickness measured by ultrasound gave more accurate predictions of body density, determined by hydrostatic weighing, than did caliper measurements. The present study compared ultrasound with circumference readings in estimating the body density of 31 white, obese women. Subcutaneous adipose tissue was measured at six body sites with an ADR model 2130 ultrasound real-time scanner. A calibrated fiberglass tape was used to take circumferences at ten body sites. Body density was computed from hydrostatic weighing using the Goldman/Buskirk formula, and percentage body fat, from the Siri equation. Mean (+/- s.d.) body density was 1.002 (+/- 0.015) g/ml, percentage body fat, 44.0 (+/- 7.5) and body mass index, 32.3 (+/- 4.5). The best prediction of body density, as determined by hydrostatic weighing, was with biceps and mid-thigh sites for ultrasound (r2 = 0.569). The combination of age, wrist, waist and upper thigh sites gave the best prediction for circumferences (r2 = 0.752). For the obese women in this study, circumference measurements provided a better estimation of body density and hence, body fat, than did ultrasound measures. A possible explanation to account for the difference is that circumference measures reflect both internal and subcutaneous adipose tissue, while only subcutaneous adipose tissue is measured with ultrasound.

Adipose Tissue↗
PubMed1987

Brain computed tomography in morbid obesity before and after gastric restriction surgery: a prospective quantitative study.

Linear brain parameters were measured by CT in 19 patients with morbid obesity (mean weight 126.4 +/- 20.5 kg) and 20 age and sex matched normal weight subjects (mean weight 62.6 +/- 14.9 kg). Ventricular parameters were slightly smaller and cortical parameters were slightly larger in the preoperative obese than in control subjects. However, only the four cortical sulci ratio was significantly different in the two groups (P = 0.02). After gastric restriction surgery and drastic weight loss (mean postoperative weight 82.9 +/- 27.4 kg), all the ventricular and cortical parameters increased, with significant change in the frontal interhemispheric fissure ratio (P less than 0.05). Obese patients followed for 23 months after surgery had less striking changes than those followed for 6 months. Morbidly obese subjects have altered brain CT dimensions which are partly reversible after weight correction.

Adult↗
PubMed1987

Severe hypertensive reaction after naloxone injection during labor.

A case of severe hypertension during labor after Naloxone injection is described in a patient with previous mild hypertension. The interaction of andogenous opioids and opiate antagonists, and their role in the control of blood pressure is discussed. Opiate antagonists should be given with caution to obstetric patients with mild to moderate hypertension.

Adult↗