Biomedical subjects
M Abramson
Publications and source records attributed to M Abramson.
Third place--Resident Basic Science Award 1990. Interleukin 1 causing bone destruction in middle ear cholesteatoma.
We previously reported the localization of interleukin 1 in the epithelial layer of human cholesteatomas. On the basis of other studies that showed interleukin 1 can stimulate fibroblasts and macrophages to produce collagenases and prostaglandins, we then proposed that interleukin 1 may play an important role in cholesteatoma-related bone resorption, also. Our immunocytochemical study involving more human cholesteatoma samples revealed the presence of interleukin 1 in bone cells and monocytes in the region of active bone destruction. In the present study, the effect of interleukin 1 on these cells found at the bone resorption site was examined. By radioimmunoassay, interleukin 1 was shown to stimulate the production of prostaglandin E2 by osteoblasts in vitro. Interleukin 1 also promoted the migration and multinucleation of bone marrow-derived monocytes. These osteoclast-like cells formed from monocytes contained tartrate-resistant acid phosphatase, and caused the resorption of the devitalized bone in vitro. Above findings suggest that interleukin 1 could cause the bone destruction in cholesteatomas, not only by stimulating the local bone cells, but also by recruiting monocytes for osteoclastic bone resorption.
Ethics and technological advances: contributions of social work practice.
Rapid technological advances in biomedicine have created ethical dilemmas for social workers and other health professionals. This article reviews three areas in which advances have been most dramatic; life support for terminally ill and elderly persons, reproductive technologies and services to severely impaired newborns. It presents principles and processes that can help structure decision making when choices are many and difficult to make. Finally, it suggests ways that social work can use its own technology to help humanize and demystify sophisticated medical technology.
Keeping secrets: social workers and AIDS.
The current epidemic of human immunodeficiency virus infection and acquired immune deficiency syndrome (AIDS) poses major ethical issues for the profession of social work, as it does for the rest of society. Although social work clearly is establishing a body of literature about the psychosocial issues surrounding AIDS, much less attention has been paid to the particular moral problems that social workers face in their day-to-day practices with people with AIDS. To begin to examine the most relevant and salient moral problems that social workers experience in their practices, 16 social workers were interviewed. The dominant moral theme that was identified was secrecy. The theme of secrecy is analyzed according to four dimensions: (1) ethical, (2) technical, (3) behavioral, and (4) existential. The clarification and justification of the use of secrecy in social work practice with people with AIDS is discussed.
A morphometric study of the effects of pressure on bone resorption in the middle ear of rats.
Bone destruction is one of the clinical features of chronic otitis media with cholesteatoma. Bone resorption may be due to the epithelial debris accumulated in the cholesteatoma epidermal sac that acts as foreign body material inducing a destructive granulation tissue and creates pressure on the bony middle ear. This compressive force then induces bone resorption. The present study was designed to replicate certain conditions similar to those in cholesteatoma leading to bone resorption. Four types of materials were implanted into the middle ear cavity of rats: (1) laminaria, an expandable seaweed material, (2) preswollen laminaria, (3) keratin powder suspension, and (4) surgical grade silicone, which when bent exerts pressure on the bulla wall. The placement of laminaria segments in the middle ear cavity of rats was followed by swelling of the implanted materials within 7 days. The bulla bone response was by neo-osteogenesis as well as active bone resorption. The new bone was observed on the external and/or internal surface of the tympanic bone. The cochlear bone also showed extensive bone resorption in the animals. Osteogenesis was rarely observed on the capsule of the cochlea. We also observed no bone resorption at sites without presence of inflammatory connective tissue between laminaria and bone. The typical multinucleated osteoclasts were often seen at the resorption area but the majority of bone resorption sites were characterized by the presence of mononuclear cells and other inflammatory cells. Preswollen laminaria, keratin powder, and silicone strips induced minimal bone resorption. No resorption was observed in the bony cochleas of these experimental groups.(ABSTRACT TRUNCATED AT 250 WORDS)
Clinical results with a percutaneous bone-anchored hearing aid.
During a 2-year period ending in July 1987, nine patients were implanted with a percutaneous bone-anchored hearing aid developed at the University of Gothenburg and Chalmers University of Technology, Sweden. Patients selection was based on the presence of conductive or mixed hearing loss in patients who are unable to wear a conventional hearing aid because of infection or ear canal problems. Patients had speech discrimination scores of at least 60% for phonetically balanced monosyllables (CID lists) at 40 dB above threshold, and a pure tone bone conduction average of 45 dB hearing loss or better. Patients were evaluated in sound field, preoperatively and postoperatively using warble tones, speech reception threshold, speech discrimination, and synthetic speech identification. The patient's unaided hearing and hearing with a bone-anchored hearing aid were compared with the patient's hearing with a standard bone conduction hearing aid. Signal to noise ratio testing with the synthetic speech identification test demonstrated that the bone-anchored hearing aid was comparable to a standard bone conduction aid. There were no complications in our series. Five patients who reported otorrhea with conventional hearing aids experienced no otorrhea after implantation. Patient satisfaction, as assessed by questionnaire, revealed that all patients preferred the bone-anchored hearing aid to previously worn hearing aids.
Asthma in the Australian community.
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Normal brain-stem auditory evoked potentials with abnormal latency-intensity studies in patients with acoustic neuromas.
Brain-stem auditory evoked potentials (BAEPs) are highly sensitive for detecting acoustic neuromas but false-negative results occur. We studied BAEPs preoperatively in 39 cases of acoustic neuroma. Absolute and interpeak latencies ipsilateral to the tumor, and interaural latency differences, were normal in four patients with small tumors. In three of these, however, results of latency-intensity studies were abnormal. In one patient, the latency-intensity result became normal postoperatively. If acoustic neuroma is suspected, and BAEPs are normal by usual criteria, latency-intensity functions should be examined to maximize chances of detecting a small tumor.
Enzootic nasal tumour of sheep.
This is the first report of Enzootic Nasal Tumours (ENT) of sheep in Israel. The report includes a detailed clinical, pathological and histopathological description of the syndrome. All 7 affected sheep suffered clinically from serous to muco-purulent nasal discharge and respiratory distress due to obstruction of the upper airway by a neoplastic process. Three of the tumours were histopathologically identified as tubular adenomas, 3 were mucoid adenomas and one was a papillary adenoma. The tumours caused destruction of the turbinate bones and nasal septum.
Impediments to implementing national policy change for mildly handicapped students.
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A free radical scavenger reduces hematoma-induced flap necrosis in Fischer rats.
Free radicals have been shown to play an important role in hematoma-induced flap necrosis. The present study investigated the effect of deferoxamine, a free radical scavenger and iron chelator, on flap necrosis. A 4 X 2 cm dorsal flap was raised in Fischer inbred rats, and 3 cc of blood from inbred donors was instilled beneath the flap. Saline-treated control animals (Group 1) were compared with two experimental groups. In Group 2, deferoxamine 150 mg/kg was administered 15 minutes before surgery and every 8 hours for 5 days. In Group 3, deferoxamine was given every 8 hours for 3 days before surgery and every 8 hours for 5 days postoperatively. Flap necrosis was assessed on postoperative day 5. Group 2 had significantly less necrosis, 18.6%, than the control group, 64.0% (p less than 0.001). Group 3, with 36.0% necrosis, also showed improvement (p less than 0.05). Group 2 and Group 3 were not significantly different. Deferoxamine, a safe and well-tolerated free radical scavenger, greatly enhanced flap survival, presumably by the neutralization of damaging free radical species and by chelation of iron.
Bone resorption in cholesteatoma: epithelial-mesenchymal cell interaction and collagenase production.
Clinical evidence has shown that chronic otitis media with cholesteatoma causes greater bone resorption than otitis media without cholesteatoma. What is the role of the epithelium and its products on the morbidity of cholesteatoma? We have studied the mechanism of collagenase production in cultures of rat epidermal cells and skin fibroblast-like cells under various conditions. The epithelial cells significantly induced mesenchymal cells to produce collagenase. We conclude that interaction between epithelial cells and fibroblast-like cells enhances production of collagenase. This enhancement of proteolytic activity may be crucial in the series of molecular events resulting in bone resorption associated with cholesteatoma.
The effect of endotoxin and prostaglandin E2 on the proliferation of keratinocytes in vitro.
Since the rate of epidermal basal cell proliferation appears to be a crucial factor in the development of acquired cholesteatoma, we studied the effect of prostaglandin E2 (PGE2) and endotoxin on the growth of keratinocytes. PGE2 and endotoxins are inflammatory mediators in chronic otitis media. Various concentrations of endotoxin and PGE2 were added to keratinocytes derived from newborn rats. The synthesis of DNA was then studied by incorporation of 3H-thymidine into the keratinocytes. We found that either endotoxin or PGE2 alone inhibited DNA synthesis by keratinocytes, while endotoxin (10 micrograms/ml) and PGE2 (10 ng/ml) together stimulated DNA synthesis by keratinocytes. These findings suggest that inflammatory mediators, such as endotoxin plus PGE2, in chronic otitis media stimulate the growth of epidermal basal cells of cholesteatoma.
Hepatic reactions to nifedipine.
Two cases in which abnormal liver function tests were associated with the use of nifedipine are reported. In both cases, liver function returned to normal after withdrawal of the drug. Evidence suggests that the toxic effect of nifedipine on the liver is due to hypersensitivity.
Type II collagen induced bone resorption in the temporal bone of rats: histological and immunohistochemical studies.
Bone resorption in the temporal bone of rats was induced by peripheral immunizations of heterogeneous type II collagen. Bone resorption was found at both the tympanic bone and the petrous bone of the otic capsule. Macrophages, fibroblasts and osteoclasts were found in the enlarged spaces of bone. Immunohistochemical studies demonstrated that macrophages, fibroblasts and osteoclasts produced collagenase and prostaglandins in the bone resorption processes, suggesting that these cells are responsible for the resorption observed.
Intraoperative BAER monitoring and hearing preservation in the treatment of acoustic neuromas.
We treated 20 cases of acoustic neuromas in the last 2 1/2 years using the suboccipital approach with intraoperative monitoring of eighth nerve function in an attempt to preserve hearing. Total tumor removal was accomplished in 18 cases. Three tumors were small (less than 2 cm in size); 3 tumors were moderate sized (2 to 3 cm) and 14 tumors were large (greater than 3 cm). In 15 cases, all BAER components were lost during surgery. These patients had no postoperative hearing. In five patients there was intraoperative preservation of some or all BAER components. These included the three patients with small tumors and two other patients with moderate sized tumors. One patient with a moderate size tumor had preservation of wave 1 only, and had no postoperative speech discrimination. One patient with a small tumor retained all 5 BAER components, but had no postoperative hearing. Three patients in our series retained functional hearing after surgery, including 3 of 5 patients with tumors 2 cm or smaller. Intraoperative BAER monitoring appears to be useful in predicting postoperative hearing. Tumor size seems to be the primary factor in preservation of hearing following acoustic neuroma surgery.
Post-transfusion purpura.
We report two cases of purpura characterised by severe immune thrombocytopenia which appeared one to two weeks after blood transfusion during elective surgery. Both patients had antibodies to the platelet P1A1 antigen and displayed high levels of platelet-bindable IgG and IgM in their serum; they were treated with glucocorticoids and recovered after four weeks. One case relapsed following a further transfusion of packed red cells. Theories of pathogenesis, methods of diagnosis, and alternative forms of therapy are reviewed.
Extending the boundaries of life: implications for practice.
Recent advances in medical technology are confounding traditional definitions of life and death and even of who is a person. This article considers the implications of these developments for social workers and presents a technique for helping clients make decisions in the face of ethical dilemmas created by new medical technologies.