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Biomedical subjects

D Halperin

Publications and source records attributed to D Halperin.

At least 19 recordsLinked to original sources
PubMed1995

Evaluation of chromosome 12 copy number in ovarian granulosa cell tumors using interphase cytogenetics.

Trisomy 12 is frequently observed in karyotypes of ovarian sex cord-stromal tumors, including adult and juvenile granulosa cell tumors (AGCTs and JGCTs). We assessed the ability to detect this abnormality in deparaffinized tissue sections of 19 ovarian GCTs (17 AGCTs, two JGCTs) and in one fibrothecoma by simultaneous in situ hybridization with fluorescent-labeled centromeric probes to chromosomes 12 (fluorescein isothiocyanate conjugated) and 17 (rhodamine conjugated). In order to quantitate the artifact introduced by nuclear slicing, such analyses were performed both on intact tissue sections and on cytospins of nuclei prepared by enzymatic dissociation from the corresponding tissue block. The series was also evaluated for numerical abnormalities of chromosome X, a less common cytogenetic finding in GCT. Twelve of 19 cases (63%) displayed evidence of trisomy 12 (defined as signal gain in > or = 10% of nuclei) in the intact section, the cytospin, or both. Trisomy for chromosome 17 was present in one case, and trisomy X was present in two cases. In tissue sections the incidence of signal gain for the chromosome 12 probe varied from 0-45% of nuclei (mean 19%). In cytospin preparations, the percentage signal gain for chromosome 12 ranged from 0 to 84% (mean 33%). This study supports the presence of trisomy 12 as a common, but not defining, cytogenetic anomaly in ovarian GCTs. Its presence, however, within only a minority of tumor cells may be partly explained by slicing artifact associated with intact tissue sections, although partial involvement of intact nuclei suggests that trisomy 12 may also be encountered as a heterogeneous abnormality within neoplastic populations of GCTs.

Adult↗
PubMed1994

[Delayed post-anoxic encephalopathy].

A case of the rare condition, delayed postanoxic encephalopathy is presented. This condition occurs after an acute hypoxic insult followed by an interval of apparent full recovery, but relapses to various degrees of renewed neurological impairment, coma or even death. Anesthetists should be aware of this entity and establish proper follow-up in patients at risk.

Anesthesia↗
PubMed1994

Bronchiolitis obliterans--current concepts.

We review current concepts about the clinical manifestations, diagnosis and treatment of patients with bronchiolitis obliterans (BO) with emphasis on clinical/pathological correlations and recent developments. BO is a relatively rare disease, but its incidence is probably higher than generally believed and is continuously rising, partly because of better recognition, but also because of increased exposure to industrial fumes, and its occurrence in lung transplantation. BO is characterized histologically by varying degrees of obliteration of the lumen of the respiratory bronchioles by organizing connective tissue often extending into the alveoli ('proliferative' BO with organizing pneumonia--BOOP) or by more extensive fibrosis and scarring of the more proximal, conductive bronchioles ('constrictive' BO). Diverse clinical conditions have been associated with the development of BO, notably viral and mycoplasma infection, toxic fume exposure and immune reactions in the setting of a collagen vascular disease, drug reaction or organ transplantation. The clinical course and features of BO may vary considerably according to the aetiology, histological pattern and stage of the disease. The most common presentation is that of a progressive dry cough and dyspnea, associated with diffuse patchy interstitial lung infiltrates on chest X-ray. In the more advanced cases, lung function tests show either restrictive or obstructive defects, depending on the extent of alveolar involvement, and hypoxemia without CO2 retention. The diagnosis is often possible on clinical grounds, however, in a seriously ill patient uncertainty should be resolved by tissue diagnosis, preferably by open lung biopsy. Treatment is based on symptomatic therapy. The use of corticosteroids is controversial, but common. Patients with BOOP are exceptional, in that there may be no underlying condition ('idiopathic' BOOP or cryptogenic organizing pneumonia--COP), a restrictive ventilatory defect is usual and the response to corticosteroids often remarkable.

Adrenal Cortex Hormones↗
PubMed1993

The association of Helicobacter pylori with gastric cancer and preneoplastic gastric lesions in Chiapas, Mexico.

BACKGROUND: Helicobacter pylori recently was identified as a risk factor for gastric cancer. Its association with preneoplastic conditions of the stomach, however, is undocumented. METHODS: Gastric biopsy specimens from 245 symptomatic patients were examined for neoplastic and preneoplastic lesions and for gastric H. pylori infection. The sera of 183 subjects were tested by enzyme-linked immunosorbent assay (ELISA) for anti-H. pylori immunoglobulin G. RESULTS: Histologic H. pylori infection, usually accompanied by acute and chronic gastritis, was found in 85.7% of patients. There was a strong association between H. pylori in the tissue and atrophy (relative risk, 15.0; 95% confidence interval, 4.2-56.6), intestinal metaplasia (relative risk, 5.7; 95% confidence interval, 1.9-16.8), and dysplasia or cancer (relative risk, 4.0; 95% confidence interval, 1.1-14.8). The ELISA was 93.2% sensitive and 57.1% specific for histologic infection with a positive predictive value of 96.1%. The overall seroprevalence rate was 86.1%, with no significant difference in rates between patients with cancer precursors and those with normal stomachs. CONCLUSIONS: In this high-risk population, precursor lesions for adenocarcinoma were associated universally with H. pylori infection.

Adult↗
PubMed1993

Expression of alpha v and beta 3 integrin subunits in rat osteoclasts in situ.

Recent findings suggest that the vitronectin receptor, a member of the integrin family, plays an important role in the attachment of osteoclasts to bone matrix. We report here the localization by in situ hybridization of the mRNA for the alpha and beta subunits of the vitronectin receptor in rat bone sections. To generate the rat-specific RNA probes used in this study, we cloned cDNA fragments of integrin chains alpha v, beta 3, and beta 5 by the polymerase chain reaction from rat cDNA. These fragments share 86-91% homology with the respective human sequences. In situ hybridization localized the alpha v and beta 3 mRNAs to regions undergoing extensive bone resorption. The histologic appearance and prestaining of bone sections for tartrate-resistant acid phosphatase (TRAP) indicated the presence of these mRNAs in osteoclasts. These observations support immunohistochemical findings that osteoclasts express high levels of the vitronectin receptor, confirm the identity of this receptor as integrin alpha v/beta 3, and suggest that osteoclasts may actively synthesize these molecules.

Amino Acid Sequence↗
PubMed1993

Differential expression of insulin-like growth factor-I (IGF-I) and IGF-II messenger ribonucleic acid in growing rat bone.

Insulin-like growth factors (IGF-I and IGF-II) are among the most abundant growth factors found in bone. Although their local production has been implicated in growth and development, localization of the cells that express these proteins is not well documented. We have studied, by in situ hybridization, the temporal and spatial expression of IGF-I and IGF-II mRNA in rat long bones at different stages of postnatal bone development. In 2-day-old rats, IGF-II was highly expressed in cartilage and in the mesodermal structures that surround the bone. At later stages of bone development, the IGF-II signal decreased in intensity, but could still be detected in the growth plate of tibial bones at 3 and 5 weeks. At this stage, the IGF-II signal in the epiphyseal growth plate was unevenly distributed and was stronger in the periphery than in the center, where it was mainly concentrated in the germinal layer and in some, but not all, cartilage columns. IGF-I, on the other hand, was only faintly detected in the periosteum at the early cartilaginous stage of bone development. At later stages, IGF-I was strongly associated with regions of ossification in the trabecular bone of the metaphysis and epiphysis and along the endosteal and periosteal surfaces. Surprisingly, we did not detect at any time IGF-I mRNA in chondrocytes of the epiphyseal growth plate. These results suggest that in the rat, IGF-II plays a role in early development of bone and in the longitudinal growth of the epiphyseal plate. IGF-I is more closely associated with the osteogenic regions and does not replace the declining levels of IGF-II in the growth plate.

Aging↗
PubMed1993

Obstructing adenoids in adolescents: changing trends?

The number of adolescents undergoing surgery for obstructing adenoids has increased significantly in our practice in recent years. Over an 11-year period during which 539 adenoidectomies were performed, the mean age of patients increased progressively from 4.6 years in 1980 to 7.88 years in 1990. The median age gradually increased over the same period from 4 to 7 years, and the standard deviation from 4.95 to 19.38. Enlarged adenoids should be considered in the differential diagnosis of adolescents suffering from nasal obstruction, snoring or obstructive sleep apnea.

Adenoidectomy↗
PubMed1992

Long-term follow-up of the effectiveness and safety of inferior turbinectomy.

The long-term effectiveness and safety of inferior turbinectomy were assessed in 186 patients who were interviewed and examined 10 to 15 years after surgery (mean 12.3 years). Relief of nasal obstruction was reported by 82 percent of the patients; rhinoscopy showed wide, clean nasal airways in 88 percent. Rhinorrhea was still a problem for 34 percent of patients, and 19 percent were receiving medical treatment for this symptom. Smell acuity had improved in 52 percent of the patients. Before turbinectomy, 32 patients had suffered from bronchial asthma; postoperatively, there was an improvement in 16, and no change in 13; 3 patients reported exacerbation of asthmatic attacks. Atrophic changes of the nasal mucosa and chronic purulent infection were not observed in any of the patients.

Adolescent↗
PubMed1991

[Pulmonary edema complicating upper airway obstruction].

A 40-year-old man who developed acute pulmonary edema following relief of upper airway obstruction is presented. The mechanism of pulmonary edema associated with upper airway obstruction is complex and not fully understood. It is therefore difficult to predict which patients will develop pulmonary edema during or after the relief of obstruction.

Acute Disease↗
PubMed1990

A synthetic thymic hormone, THF-gamma 2, repairs immunodeficiency of mice cured of plasmacytoma by melphalan.

BALB/c mice cured of large MOPC-315 plasmacytomas by melphalan remain deficient in their spleen T-cell functions. This was manifested by impairment of the allogeneic and the antibody responses in vitro to SRBC and in decreased numbers of T-cells including their subsets CD4 and CD8. IL-2 production and specific cytotoxicity against MOPC-315 tumor cells were, on the other hand, maintained. Treatment of these cured mice by in-vivo administration of THF-gamma 2, an octapeptide from calf thymus, repaired these deficits. This was evidenced by in vitro tests with spleen cells which manifested an increased allogeneic response and elevated generation of primary antibody response, restoration of T-cell subpopulations to normal and an enhanced IL-2 production above normal levels. The potential use of THF-gamma 2 as supportive therapy in cancer treatment is suggested.

Animals↗
PubMed1989

THF-gamma 2, a thymic hormone, increases immunocompetence and survival in 5-fluorouracil-treated mice bearing MOPC-315 plasmacytoma.

The effect of the thymic hormone, THF-gamma 2, on the immunocompetence of 5-fluorouracil (5-FU)-treated BALB/c mice, bearing MOPC-315 tumor, was examined. Treatment of noninoculated or tumor-bearing mice with THF-gamma 2 after 5-FU injection, resulted in an increase in the antibody response to sheep red blood cells and in the allogeneic response in spleen cell cultures and had no effect on the concanavalin-A-induced interleukin-2 secretion beyond that caused by 5-FU alone. Treatment with either 5-FU alone or 5-FU and THF-gamma 2 resulted in restoration to normal values of Lyt1- and L3T4-positive populations in tumor-bearing mice. THF-gamma 2 prolonged the survival time of mice bearing MOPC-315 tumor beyond that observed in mice treated with 5-FU alone.

Animals↗
PubMed1989

Acute airway obstruction and achalasia of the esophagus.

Patients with achalasia tolerate considerable distension of the esophagus. Respiratory symptoms usually are due to regurgitation and pulmonary aspiration of retained food rather than to a space-occupying mechanism. We describe a case of previously undiagnosed achalasia presenting in an elderly woman with symptoms consistent with tracheal obstruction of acute onset.

Acute Disease↗
PubMed1988

Induction by an immunogenic immunomodulating agent of nonspecific T cell suppression of lymphocyte responsiveness in MLR but not of antibody production.

Spleen cells derived from BALB/c mice that had been repeatedly immunized with the methanol extraction residue (MER) fraction of tubercle bacilli exhibited a depressed capacity to act as responder cells in allogeneic and syngeneic mixed lymphocyte reactions (MLR). Previously reported studies revealed that such spleen cells are also defective in the in vitro generation of antibodies. In order to determine the nature of the cells responsible for the depressed MLR reactivity, purified populations of splenic macrophages, B lymphocytes, T lymphocytes originating from normal and from MER-immunized mice, and cell culture supernatants were added to MLR mixtures consisting of normal mouse splenocytes. Macrophages originating from MER-immunized mice and their culture supernatants exerted a significantly higher suppressive effect on MLR than that of corresponding preparations from normal mice. Splenic T cells originating from MER-immunized mice and their supernatants also significantly suppressed the MLR response. However, the same T cell populations that were inhibitory in MLR failed to suppress the in vitro generation of antibodies against sheep red blood cells in the presence of either MER or 2-mercaptoethanol. These and previously reported findings indicate that a nonspecific immunomodulating agent, MER, can, under certain conditions of treatment, elicit the induction of nonspecific suppressor T cells for MLR but not for antibody production, and, accordingly, can inhibit cellular and humoral immunological responsiveness by different mechanisms.

Adjuvants, Immunologic↗