摘要:

Carcinoma of unknown histogenesis or primary site is an increasingly recognized syndrome regarded by most physicians as having a grim prognosis. Elaborate evaluations using low yield, and often misleading, radiologic studies focused on identifying primary sites in the lung, liver, pancreas, or gastrointestinal tract offer little benefit to the vast majority of patients. Increasing evidence has accumulated showing that subsets of patients within this broad syndrome exist in whom recognition and proper therapy may result in meaningful prolongation of life or potential cure. In this review, clinical clues and diagnostic aids for identification of nine treatable subsets of patients with the carcinoma of unknown origin (CUO) syndrome are emphasized. Current state-of-the-art tretment for each subset with subsequent end results are stated.

ISSN:0002-9629    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

Endothelial injury or dysfunction has long been postulated to promote atherogenesis, but structural alterations of endothelium in atherosclerosis have remained obscure. We report the common occurrence of actin-containing stress fibers, stainable by rhodaminephalloidin, in endothelium overlying atherosclerotic lesions in cholesterol-fed rabbits. Nonlesioned areas in the same aortas showed normal endothelium with minimal development of stress fibers, which was no different from the appearance of endothelium in chow-fed rabbits. Microtubule organization revealed by immuno-fluorescence appeared normal in all areas. The development of stress fibers may be related to an altered substratum for endothelial attachment. This study provided no evidence to relate stress fiber formation with lesion initiation, but an association with well-developed foam cell lesions was evident.

ISSN:0002-9629    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

19-Nor-deoxycorticosterone (19-nor-DOC) is a mineralocorticoid that is increased in some forms of experimental and human hypertension. The pivotal step in 19-nor-DOC biosynthesis is adrenal P450 19-hydroxylase, but this enzyme has not been clearly distinguished from P450 11β/18-hydroxylase. This study attempted to specifically inhibit adrenal 19-hydroxylation of deoxycorticosterone (DOC) using a suicide aromatase inhibitor, 19-acetylenic androstenedione (19-AA). Purified bovine P450 11β/18/19-hydroxylase was incubated with excess substrate DOC, adrenodoxin, and adrenodoxin reductase in the presence of increasing doses of the inhibitor, 19AA. 11β-, 18-, and 19-hydroxylation were measured by quantification of corticosterone, 18-OH-DOC, and 19-OH-DOC respectively. Measurements of these products demonstrated that 11β- and 18-hydroxylation was not inhibited whereas 19-hydroxylation was inhibited as manifested by decreased 19-OH-DOC formation (p <.05). The IC50 of 19-AA was approximately 10-12M. The specific inhibition of 19-hydroxylation suggests that the 19-hydroxylase may be an enzyme distinct from the P450 11β/18-hydroxylase. This further suggests that 19-nor-DOC biosynthesis may be under independent regulation and may be amenable to specific in vivo inhibition.

ISSN:0002-9629    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

The incidence of beta cell damage attributable to pentamidine treatment of pneumocystis pneumonia is increasing in frequency because of the AIDS epidemic. We carried out in vitro studies in perfused rat islets using insulin secretion as an index of beta cell damage to study the effects of pentamidine and to test whether glucose can prevent toxicity in this physiologic model. Isolated islets were cultured for 16–18 hours of static incubation, in a culture medium containing 100 mg/dl glucose, with or without pentamidine (10-6M, a therapeutic concentration). Islets were then perfused with media containing 60 mg/dl followed by 300 mg/dl glucose concentrations to study the insulin secretory response. Incubation of islets with pentamidine was associated with subsequent basal hypersecretion of insulin (0.40 ± 0.05 μ/islet .5 minute vs. 0.18 ± 0.04 μ/islet .5 minute, p<.005), and an insulin secretory response to glucose which was completely abolished (0.05 ± 0.04 μU/islet .5 minute versus 1.12 ± 0.02 μU/islet .5 minute, p<.005). To determine whether glucose may protect against the effects of pentamidine, islets were then exposed to high glucose concentrations during simultaneous incubation with pentamidine. Coincubation with high glucose did not prevent these insulin secretory defects. A more extended culture of pentamidine-treated islets in the absence of pentamidine and at a glucose concentration of 100 mg/dl did not result in any recovery of insulin secretion. We conclude that pentamidine-induced beta cell damage is irreversible, not preventable by incubation with high glucose concentrations, and may therefore result from a mechanism different to that of alloxan.

ISSN:0002-9629    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

Medullipin I causes a delayed onset depressor response when injected intravenously into rats. The glyceryl compounds selachyl alcohol (SA) and monoolein (MO) cause similar vasodepression. The neutral lipid 1-O-hexadecyl-2-acetyl-sn-glycerol (HAG) was suggested by Blank et al to be medullipin I (Med I, formerly ANRL). Biologic comparisons were made between Med I and various glyceryl compounds, including SA, MO, HAG, alkyl glyceryl ethers of phosphatidyl choline (termed APRL by us), diacylated SA, and the n-butyl boronic acid derivative of Med I also was evaluated. The delay in onset of the depressor response to Med I was reduced by the injection of Med I into the portal vein; that of SA and MO was not. Med I, SA, and MO were activated by the liver, while APRL and HAG were not. Tween 20 inhibited Med I, SA, and MO, but not APRL and HAG. Proadifen (SKF 525A) inhibited Med I, but not SA and MO. The n-butyl boronic acid derivatives of SA, MO, and Med I were inactive. Med I, like SA and MO, appeared to have two hydroxyl groups in close proximity. It was concluded that Med I is neither HAG, APRL, SA, nor MO.

ISSN:0002-9629    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

Immediate type-generalized reactions to protamine sulfate are uncommon but may be fatal. The mechanisms of severe or fatal reactions are unknown in most cases. One theory is that contaminating fish (salmon) proteins present in protamine solutions induce anaphylaxis in salmon-sensitive subjects. A second hypothesis is that protamine interacts with anti-salmon IgE to cause anaphylaxis. We assessed these hypotheses by establishing an indirect amplified enzyme-linked immunosorbent assay (ELISA) for IgE to salmon. Sera obtained from two subjects anaphylactically sensitive to salmon demonstrated high binding to salmon that was not inhibited by preincubation of sera with 500 or 1000 μg of protamine orAspergillus fumigatus.Serum from a patien who experienced anaphylactic shock from protamine was indistinguishable from control sera in the ELISA for IgE to salmon. Anti-protamine IgE could not be demonstrated in separate experiments. The assays prove that 1) serum IgE to salmon is not inhibited by protamine and 2) serum from a patient experiencing a severe reaction to protamine did not contain IgE to salmon or protamine. The experiments do not support the notion that there is cross-reactivity between IgE to salmon and protamine sulfate in the cases evaluated.

ISSN:0002-9629    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

There are 36 reported cases of metastatic pituitary carcinoma and almost half (44%) of these were associated with syndromes of hormonal hypersecretion. The case of a 56-year-old acromegalic man with cervical lymphatic and spinal metastases from a primary pituitary carcinoma is described. Elevated basal levels of plasma growth hormone (GH) and insulin growth factor-1/Somatomedin C (IGF-1/SmC) were found. GH levels did not increase after TRH or LHRH administration but decreased after L-Dopa and glucose. Immunostaining of the metastatic tumor for GH and electron microscopy findings confirmed the diagnosis of pituitary GH-secreting carcinoma. Striking clinical improvement and a 46% decrease in plasma GH levels wee observed with bromocriptine treatment, although IGF-1/SmC levels increased during therapy. The clinical course of most reported cases of pituitary adenocarcinoma has been one of progressive intracranial expansion of a pituitary neoplasm. In only 25% were metastatic lesions discovered antemortem, and disabling symptomatology caused by metastases was rare. Only four previously reported patients of 36 with pituitary carcinoma had acromegaly.

ISSN:0002-9629    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

The symptoms of hypothyroidism are protean and include apathy, somnolence, lethargy, personality change, and intellectual deterioration. Many of these symptoms may be related to hypothyroid-induced sleep disorders. Hypothyroidism is associated with abnormal ventilatory drive, abnormal sleep architecture, and sleep apnea. Central, obstructive, and mixed patterns of sleep apnea are commonly observed in hypothyroidism. A case of severe sleep apnea in a grossly myxedematous patient who improved dramatically following thyroid replacement alone is presented. Myxedema is a reversible cause of sleep apnea, and thyroid function testing should be considered in its diagnostic work-up.

ISSN:0002-9629    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

A left ventricular pseudoaneurysm was diagnosed by two-dimensional echocardiography and color-flow Doppler imaging, and confirmed by computerized tomography and angiocardiography, in a man with known coronary disease who had had recent recurrent systemic emboli. A thrombus within the pseudo-aneurysm was visualized, and its disappearance on serial echocardiograms coincided with the occurrence of embolization to the aortic bifurcation.

ISSN:0002-9629    

出版商:OVID    

年代:1989

数据来源: OVID

ISSN:0002-9629    

出版商:OVID    

年代:1989

数据来源: OVID