Expression of androgen receptors in nasopharyngeal angiofibroma: an immunohistochemical study of 24 cases

Angiofibromas are uncommon benign tumors that typically occur in the lateral portion of the nasopharynx of adolescent boys. Numerous reports showed indirect evidence for the presence of sex-hormone receptors, i.e., androgen (AR), estrogen (ER), and progesterone (PR) receptors, in these tumors. The goal of the current study was to show direct evidence of sex hormone receptor expression in angiofibromas with use of sensitive immunocytochemical techniques and to document which cell populations express the receptor. Twenty-four nasopharyngeal angiofibromas were obtained from archived tissue, and immunocytochemical studies were performed with antibodies to AR, PR, and ER. Positive stromal and endothelial nuclear immunostaining, implying the presence of ARs, was seen in 18 (75%) of 24 cases, whereas 2 (8.3%) of 24 cases were positive with antibodies to PR. None of the 24 cases examined was positive with antibodies to ER. These results provide the first direct evidence for the presence of ARs in angiofibromas, which might help to explain the unique clinicopathologic features of these tumors.     

HMR 1883, a novel cardioselective inhibitor of the ATP-sensitive potassium channel. Part II: effects on susceptibility to ventricular fibrillation induced by myocardial ischemia in conscious dogs

The activation of the ATP-sensitive potassium channel (KATP) during myocardial ischemia leads to potassium efflux, reductions in action potential duration and the formation of ventricular fibrillation (VF). Drugs that inactivate KATP should prevent these changes and thereby prevent VF. However, most KATP antagonists also alter pancreatic channels, which promote insulin release and hypoglycemia. Recently, a cardioselective KATP antagonist, HMR 1883, has been developed that may offer cardioprotection without the untoward side effects of existing compounds. Therefore, VF was induced in 13 mongrel dogs with healed myocardial infarctions by a 2-min coronary artery occlusion during the last minute of a submaximal exercise test. On subsequent days, the exercise-plus-ischemia test was repeated after pretreatment with HMR 1883 (3.0 mg/kg i.v., n = 13) or glibenclamide (1.0 mg/kg i.v., n = 7). HMR 1883 (P < .001) and glibenclamide (P < .01) prevented VF in 11 of 13 and 6 of 7 animals, respectively. Glibenclamide, but not HMR 1883, elicited increases in plasma insulin and reductions in blood glucose. Glibenclamide also reduced (P < .01) both mean coronary blood flow and left ventricular dP/dt maximum as well as the reactive hyperemia induced by 15-sec coronary occlusions (-30.3 +/- 11%), whereas HMR 1883 did not alter this increase in coronary flow (-3.0 +/- 4.7%). Finally, myocardial ischemia (n = 10) significantly (P < .01) reduced refractory period (control, 121 +/- 2 msec; occlusion, 115 +/- 2 msec), which was prevented by either glibenclamide or HMR 1883. Thus, the cardioselective KATP antagonist HMR 1883 can prevent ischemically induced reductions in refractory period and VF without major hemodynamic effects or alterations in blood glucose levels. These data further suggest that the activation of KATPs may play a particularly important role in both the reductions in refractory period and lethal arrhythmia formation associated with myocardial ischemia.     

Mycotoxicosis in chicks produced by toxins from Phomopsis sp. or Diaporthe phaseolorum var. sojae

The possibility of producing toxic effects in day-old chicks with mycotoxins from Phomopsis sp. or Diaporthe phaseolorum var. sojae isolates was studied. Evidence was found that Phomopsis sp., but not Diaporthe, produces hepatic necrosis with high mortality in chicks. Enzymatically, the hepatotoxin produced by Phomopsis sp. caused an increase in the level of liver glucose-6-P dehydrogenase. Mycotoxicosis caused by Phomopsis sp. was compared with lupinosis.     

Treating major depression in primary care practice: an update of the Agency for Health Care Policy and Research Practice Guidelines

The Depression Guideline Panel of the Agency for Health Care Policy and Research in 1993 published recommendations for treating major depression in primary care practice that were often based on studies of tertiary care psychiatric patients. We reviewed reports of randomized controlled trials in primary care settings published between 1992 and 1998. This evidence indicates that both antidepressant pharmacotherapy and time-limited depression-targeted psychotherapies are efficacious when transferred from psychiatric to primary care settings. In most cases, the choice between these treatments should depend on patient preference. Studies to date suggest that improving treatment of depression in primary care requires properly organized treatment programs, regular patient follow-up, monitoring of treatment adherence, and a prominent role for the mental health specialist as educator, consultant, and clinician for the more severely ill. Future research should focus on how guidelines are best implemented in routine practice, since conventional dissemination strategies have little impact.     

Sister-chromatid exchanges in lymphocytes in women with cancer of the breast

Examination of sister-chromatid exchanges (SCE) in lymphocytes may be useful for the evaluation of exposure to mutagens/carcinogens. Information of a possible association between SCE and cancer is scarce. We therefore examined SCE in peripheral lymphocytes in 131 women, aged 17-90 years (median 51.8 years), coming to operation because of a tumor of the breast. Venous blood samples were cultivated during PHA stimulation in the presence of BrdU. After treatment with colcemid (R), fixation, treatment with bisbenzimide and staining with Giemsa, 30 metaphases were scored in each specimen. 52 patients with peroperatively demonstrated carcinoma of the breast had 9.39 +/- 0.17 SCE/cell and the remaining 79 women with non-malignant fibroadenomatosis had 9.88 +/- 0.18 SCE/cell. By multiple regression analysis it appeared that the character of the tumor, the patient's age, hormone treatment and preoperative examination by mammography all were without significant influence on the SCE rate. A statistically significant correlation was found between SCE and cigarette smoking. THe 45 cigarette-smoking patients had 10.49 +/- 0.23 SCE/cell compared with 9.26 +/- 0.13 SCE/cell in the 86 non-smokers. It was concluded that spontaneous SCE in lymphocytes is not an indicator of carcinoma of the breast.     

Direct association of messenger RNA labeled in the presence of fluoroorotate with membranes of the endoplasmic reticulum in rat liver

A review of all morphine classical conditioning studies performed since Pavlov reveals significant shifts in methodological and conceptual thinking during the past 7 decades. These shifts have tended to obscure the fact that a great deal of basic data are still needed before morphine classical conditioning can be understood. These data are needed to help clarify the relationship between drug conditioning and drug addiction. Recent evidence, for example, suggests that once morphine autonomic conditional reactions are established, they are highly resistant to extinction. The inclusion of these types of data in any conceptualization of drug dependency would appear to be of help in the formulation of new clinical approaches to this problem.