摘要:

Estrogen replacement therapy (ERT) is suggested for women with symptomatic estrogen deficiency, but patients with breast cancer are advised against ERT because of concerns that ERT may precipitate cancer recurrence. The attitudes of women with breast cancer regarding ERT is critical in the design of appropriate strategies for the management of their menopause. A randomly selected group of 224 women with breast cancer responded to an anonymous survey that addressed the presence of menopause, antecedent therapies, symptoms related to estrogen deficiency, concerns about osteoporosis or heart disease, attitude about ERT, and perception about ERT-related cancer risk. Among women who completed the survey, 77% were postmenopausal and 81% had had multimodality therapy. Of menopausal women, 27% believed they needed some treatment for menopause and 8% had taken ERT since cancer diagnosis. Most women were afraid that ERT may precipitate cancer recurrence (78%) but they also were concerned about the menopause-related risk of osteoporosis (70%) and heart disease (72%). Overall, 44% of menopausal women were willing to consider ERT under medical supervision. Those treated with surgery alone were distinct in that 71% would consider ERT (p < 0.04). Premenopausal women were more concerned about osteoporosis (82% vs. 66% for postmenopausal), heart disease (92% vs. 73%), and the possibility that ERT may precipitate cancer recurrence (98% vs. 73%). Yet, at the same time, they were more willing to consider ERT under medical supervision (59% vs. 40% for menopausal). The present study underscores that women with breast cancer are very aware and concerned about the adverse health consequences of estrogen deficiency and would consider ERT under medical supervision. Treatment background, menopausal status, and symptomology affect patient attitudes toward ERT. It will be important to evaluate the role of ERT in the management of menopause in carefully selected women under rigorous medical supervision.

ISSN:0002-9629    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

The minutes immediately after cessation of strenuous exercise have been termed the “vulnerable period” regarding the occurrence of lethal cardiac arrhythmias. In the present study, we analyzed the rates of change with a high degree of temporal resolution of factors known to be associated with induction of arrhythmic activity. Thirteen subjects walked and ran on a treadmill to the point of exhaustion after a modified Bruce protocol. Samples were drawn from the antecubital vein immediately before exercise, at the moment exercise stopped, and at 1, 2, 3, 5, and 10 minutes of recovery. Plasma potassium concentration rose during exercise from 3.98 ± .05 to 5.09 ± .09 mEq/L. After the exercise period, plasma potassium fell rapidly. The mean maximum rate of change was −0.54 ± .04 mEq/L/min, and −0.88 ± .08 mEq/L/2 min. Plasma epinephrine concentration increased from 63 ± 14 to 497 ± 41 pg/ml and norepinephrine increased from 503 ± 57 to 2800 ± 519 pg/ml during exercise. During the first minute after cessation of exercise, the concentrations of both catecholamines increased still further. We propose that the rapid decline of potassium concentration while catecholamine levels are elevated to near maximal levels may contribute to the vulnerability of some individuals to post exercise arrhythmias.

ISSN:0002-9629    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

The redistribution of cathepsin B, a lysosomal enzyme, from the lysosomal pellet to the zymogen pellet in the subcellular fractionation, the colocalization of cathepsin B with digestive enzyme, and increased cellular, lysosomal, and mitochondrial fragility within acinar cells have been found during the early stages of caerulein-induced acute pancreatitis in rats. In the present study, the authors investigated the protective effects of prostaglandin E1 and E2, a combined therapy of these prostaglandins, and a new, synthetic, low molecular weight protease inhibitor, ONO3307, on the exocrine pancreas in this noninvasive model of experimental pancreatitis in vivo and in vitro. Prostaglandin E2, but not E1, prevented hyperamylasemia, congestion of amylase and trypsinogen in the acinar cells, redistribution of cathepsin B, and amylase and lactate dehydrogenase discharge from the dispersed acini. It also prevented cathepsin B leakage from the lysosomes and malate dehydrogenase leakage from the mitochondria in an almost dose-dependent manner, particularly at the dose of 100 μg/kg/hr continuous infusion. Furthermore, the combined therapy of prostaglandin E2 with ONO3307 strongly inhibited all the parameters tested in this study. This combination therapy seems to be the most effective against secretagogue-induced pancreatic injuries. These results indicate that cellular and sub-cellular organellar fragility seem to be closely involved in the pathogenesis of acute pancreatitis. Prostaglandin E2 seems to have important cytoprotective effects on the biologic membranes, such as a stabilizer of lysosomal or mitochondrial membranes. In addition, these findings also suggest the crucial roles of some unknown proteases in the etiology of acute pancreatitis, and indicate the clinical effectiveness of prostaglandins and this type of low molecular weight protease inhibitor for acute pancreatitis.

ISSN:0002-9629    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Normal insulin secretagogues, including glucose, usually have little influence on insulin secretion from insulinomas. Therefore, insulinomas typically cause fasting hypoglycemia with relative hyperinsulinemia. This report describes a patient with hyperinsulinemia due to an islet cell adenoma with microadenomatosis, which, upon provocative in vivo testing, was found to be profoundly responsive to hypoglycemic and hyperglycemic stimuli. A 72 hr fast followed by brisk exercise resulted in a gradual reduction of serum glucose and insulin concentrations, but did not provoke symptomatic hypoglycemia. Oral glucose tolerance testing resulted in a prompt 10-fold increase in serum insulin accompanied by a mildly symptomatic and gradual fall in serum glucose to 30 mg/dl 90 minutes after glucose ingestion. An intravenous glucose challenge caused an acute increase in serum insulin to more than 1200 μU/ml with a resulting serum glucose of 11 mg/dl 25 minutes later, associated with loss of consciousness. Although a prolonged fast has proven to be the best diagnostic test for insulin secreting tumors, many other provocative tests that use normal insulin secretagogues have been somewhat useful in this regard. The patient in this report supports the concept that insulinomas vary widely in their response to a number of normal physiologic regulators of insulin secretion, including the serum glucose concentration. A variety of provocative tests may be needed to fully evaluate the rare patient in whom there is a strong clinical suspicion of insulinoma but who has a nondiagnostic prolonged fast.

ISSN:0002-9629    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Optimum treatment of tuberculosis in persons with human immunodeficiency virus (HIV) infection is still being defined. Tuberculosis treatment failure in an HTV-infected patient is described and 10 similar cases from the medical literature are reviewed to search for common patterns associated with an adverse outcome of therapy in this setting. Six patients were poorly compliant. In nine patients, the subsequent episode of tuberculosis was disseminated or extra-pulmonary; in four the central nervous system was involved. In five patients, a problem with rifampin usage was encountered: Three had rifampin-resistantMycobacterium tuberculosis, one experienced an adverse reaction to rifampin, leading to withdrawal from the regimen after 1 week, and one was receiving a drug that may interfere with rifampin's antimycobacterial effect. This case report and literature review suggest that particular attention should be directed toward ensuring that patients with HTV infection comply with treatment of tuberculosis. For the majority of patients, the already stretched resources available for the treatment of tuberculosis and HIV infection should be devoted to compliance enhancement rather than to more prolonged or intensive drug regimens. However, it should be emphasized that patients with disseminated tuberculosis or central nervous system disease and those who are not able to receive rifampin because of drug resistance or an adverse reaction should be managed individually.

ISSN:0002-9629    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Epidermodysplasia verruciformis (EV) presents a genetically determined, unusual susceptibility to infection with EV-specific human papillomaviruses (HPVs) related to abrogation of immunosurveillance exclusively against these viruses. The cutaneous viral carcinogenesis depends upon potentially oncogenic HPVs, the cocarcinogenic effect of ultraviolet irradiation, and genetic host factors, presumably a defect of anti-oncogenes or alleles of major bistocompatibility complex and tumor necrosis factor locus involved in antigen presentation.

ISSN:0002-9629    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

The human immunodeficiency virus (HIV) is a member of a family of retroviruses that cause chronic persistent infections in animals and in humans. The structure of this virus resembles that of other retroviruses but also contains important and complex regulatory elements. The expression of HIV can be influenced by the action of exogenous agents and cytokines. HIV has been isolated from a number of cell types, including cells in the skin, using sensitive detection methods such as the polymerase chain reaction and in situ hybridization. This article is a basic overview of the molecular biology of HIV and its presence in skin.

ISSN:0002-9629    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Of the 1446 AIDS cases reported in Romania, 79% were in the pediatric age group. Of these children, 28% lived with their families, 30% were orphans, and 42% were abandoned. Among the AIDS-affected children, 32% were less than 1 year old and 67% were 1–4 years old. The natural history of AIDS in Romania was characterized by a high death rate from opportunistic infections. Chronic undernutrition imposed by the communist program of “rational feeding of the population,” immunodepression induced by the radiation generated by the accident at Chernobyl, hard physical work in an environment intensely polluted by industrial waste, excessive use of injectable therapies and transfusions of HIV-untested blood, lack of education of the medical staff and the population, and tourism have contributed to the AIDS epidemic in Romania. Kaposi's sarcoma was infrequent (7.7%) in AIDS patients. However, a significant number of European-type Kaposi's sarcoma cases with negative tests for the HIV infection were reported.

ISSN:0002-9629    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Like many other cell surface receptors for nutrients and polypeptide hormones, the insulin receptor undergoes a complex endocytotic itinerary. Upon insulin binding, the receptor is activated as a tyrosine-specific protein kinase and autophosphorylates. This autophosphorylation is necessary for the receptor to internalize. After endocytosis, the ligand (insulin) and its receptor are dissociated. Most of the insulin is degraded, whereas the receptors are largely recycled to the cell surface. The signals in the receptor that control and specify its endocytotic pathway are beginning to be understood. Through the techniques of in vitro mutagenesis, noninternalizing receptors have been engineered and their structural and functional properties have been analyzed. For example, the immediate submembranous domain of the insulin receptor has been found to contain sequences (Gly-Pro-Leu-Tyr and, to a lesser extent, Asn-Pro-Gln-Tyr) that are necessary for normal endocytosis. Receptors deleted or mutated in these sequences retain tyrosine kinase activity but fail to undergo endocytosis. Unlike the better understood low density lipoprotein and transferrin receptors, however, these sequences are not sufficient for endocytosis. An insulin receptor with only these sequences exposed in the cytoplasm does not internalize. Tyrosine kinase activity is thought to be needed to lead to autophosphorylation and a conformational change that exposes the otherwise buried endocytosis sequences in the normally dimerized insulin receptor. Non-internalizing mutants of the insulin receptor have been used to examine the role of endocytosis in insulin action. It was found that an endocytosis-defective receptor could induce a short-term metabolic action of insulin (glycogen synthetase stimulation) as well as longer-term mitogenic effects of insulin. Furthermore, insulin action deactivated after the hormone was removed from the noninternalizing receptors. Apparently, endocytosis is not necessary for insulin action, but probably is important for removing the insulin from the cell so the target cell for insulin responds in a time-limited fashion to the hormone.

ISSN:0002-9629    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

The ability of vitamin A and its derivatives to induce differentiation in certain target tissues has been appreciated for nearly a century. Recently, oral all-trans retinoic acid (ATRA), a vitamin A metabolite, has been shown to induce terminal differentiation of leukemic cells in patients with acute promyelocytic leukemia (APL). Complete remissions are obtained and normal hematopoiesis is established in an outpatient setting with minimal side effects in the majority of cases. Although remissions are not durable, disseminated intravascular coagulation, a frequent complication of remission induction in APL, is avoided by oral ATRA prior to definitive chemotherapy. The molecular basis for the efficacy of ATRA in APL appears to be the involvement of the retinoic acid receptor α locus in the t(15;17) translocation breakpoint characteristic of APL.

ISSN:0002-9629    

出版商:OVID    

年代:1992

数据来源: OVID