College students'' high-risk sexual behavior following alcohol consumption

A new and portable electronic device called the "Digital Phagometer" is described for the time based counting of spontaneous swallowing. This device is composed of a piezoelectric sensor and a digital event counter/ recorder which can be downloaded to any IBM-compatible PC. The sensor of Digital Phagometer is placed and fixed on the coniotomy region between the cricoid and thyroid cartilage. In this way, it is capable of sensing each upward and downward movement of the larynx produced by spontaneous movement as a function of time. Spontaneous swallowing was measured 1-4 h after lunch in 21 normal subjects and 21 patients with Parkinson's disease (PD). The mean frequency of spontaneous swallowing was 0.8 counts/min in PD patients and 1.18 counts/ min in normal subjects (p < 0.05). During the intake of 200 ml water, the mean frequency of voluntary swallowing did not differ significantly between the two groups (24.6 counts/min in normals vs. 22.3 counts/min in PD patients), but the time necessary to swallow the same volume of water was longer in the PD group.     

The use of EUS to diagnose malignant portal venous system invasion by pancreatic cancer

BACKGROUND: CT scanning and mesenteric angiography are insensitive tests diagnosing vascular invasion by pancreatic cancer. Endoscopic ultrasound (EUS) has been proposed as an alternative. The sensitivity, specificity, and accuracy of specific EUS criteria for diagnosing malignant invasion of the branches of the portal venous system have not been determined. METHODS: This is a prospective blinded evaluation of EUS and angiography to diagnose malignant invasion of the portal venous system by pancreatic cancer in 45 patients, 28 of whom underwent surgery. Surgical staging was used as the gold standard for determining the accuracy of EUS and angiography. RESULTS: Four EUS criteria were studied and the overall accuracy rates were as follows: irregular venous wall (87%), loss of interface (78%), proximity of mass (73%), and size (39%). Although "irregular venous wall" was the most accurate, it suffered from a low sensitivity rate (47%) because of its relative inability to detect superior mesenteric vein invasion (sensitivity of 17%). The angiographic criteria had accuracy rates of 73% to 90% with low sensitivity rates (20% to 77%). The clean resection rate was 86% when all tests were used, 78% if EUS was used without angiography, and 60% if only angiography was used. CONCLUSION: EUS is highly sensitive for detecting portal and splenic vein invasion by pancreatic cancer, but may be insensitive for superior mesenteric vein involvement.     

Uterine tumors resembling ovarian sex-cord tumors. A clinicopathologic analysis of fourteen cases

Uterine tumors with histologic resemblances to ovarian sex-cord tumors were encountered in 14 women in the fourth to sixth decades of life, most of whom had abnormal vaginal bleeding and enlarged uteri suggesting leiomyomas. The tumors in six cases (Group I) were identical to one or another form of well-recognized endometrial stromal tumor except for focal epithelial-like differentiation resembling that seen in sex-cord tumors. These tumors were mostly poorly circumscribed large mural masses. The focal sex-cord-like differentiation was manifested by cords, trabeculae, nests and tubules of epithelial-like cells; eosinophilic bodies resembling Call-Exner bodies were seen in one case. Five of the six patients with tumors of this type have been followed for postoperative intervals of 22 months to 15 years, and pelvic recurrences have developed in three. The tumors in eight cases (Group II) differed from those in Group I by having a predominant or exclusive pattern reminiscent of an ovarian sex-cord tumor. These tumors, most of which were single, well-circumscribed, yellow to tan, mural masses 4 to 10 cm in diameter, appeared benign, with no recurrence during postoperative periods of four months to seven years. The relations of the two groups of tumors to one another and to previously described similar tumors. including so-called granulosa-cell tumors and "plexiform tumors" of the uterus, are discussed, and an origin from endometrial stromal cells is postulated.     

Comparison of bax, waf1, and IMP dehydrogenase regulation in response to wild-type p53 expression under normal growth conditions

Recently, we demonstrated that downregulation of inosine-5'-monophosphate dehydrogenase (IMPD; IMP:NAD oxidoreductase, EC 1.2.1.14), the rate-limiting enzyme for guanine nucleotide biosynthesis, is required for p53-dependent growth suppression. These studies were performed with cell lines derived from immortal, nontumorigenic fibroblasts that express wild-type p53 conditionally by virtue of a metal-responsive promoter. Here, the p53-dependent properties of the original "p53-inducible" fibroblasts are presented in detail and compared to related properties of epithelial cells that also express wild-type p53 conditionally, but by virtue of a temperature-responsive promoter. Both types of p53-inducible cells were designed to approximate normal physiologic relationships between the host cell and the regulated p53 protein. Together, they were used to investigate expression relationships between IMPD and other p53-responsive genes proposed as mediators of p53-dependent growth suppression. In both types of cells, IMPD activity, protein, and mRNA were consistently coordinately reduced in response to p53 expression. In contrast, mRNAs for waf1, bax, and mdm2 showed disparate patterns of expression, being induced in one conditional cell type, but not the other. This distinction in regulation pattern suggests that under normal growth conditions, unlike IMPD downregulation, bax and waf1 induction is not a rate-determining event for p53-dependent growth suppression.     

Sarcomas and related proliferative lesions of specialized prostatic stroma: a clinicopathologic study of 22 cases

Sarcomas and related proliferative lesions of the specialized prostatic stroma have been the subject of case reports and, thus, have not been well characterized. We reviewed the clinicopathologic features of 22 cases and studied the immunohistochemical profile of 9. Patient age ranged from 25 to 86 years; mean age was 54 years, and peak incidence was in the 6th and 7th decades. The most common clinical presentation was urinary retention, then abnormal results of digital rectal examination, hematuria or hematospermia, and a palpable rectal mass. The cases were grouped into two categories: prostatic stromal proliferation of uncertain malignant potential (PSPUMP, 18 cases) and prostatic stromal sarcoma (PSS, 4 cases) based on the degree of stromal cellularity and the presence of mitotic figures, necrosis, and stromal overgrowth. Four histologic patterns of PSPUMP were identified: (1) hypercellular stroma with scattered cytologically atypical cells associated with benign glands, (2) hypercellular stroma with minimal cytological atypia associated with benign glands, (3) hypercellular stroma with or without cytologically atypical cells, associated with benign glands in a "leaflike" growth pattern that resembled phyllodes tumors of the mammary gland, and (4) hypercellular stroma without cytologically atypical stromal cells and without glands. Prostatic stromal sarcoma showed greater cellularity, mitoses, necrosis, and stromal overgrowth than PSPUMP and consisted either of stromal elements with benign glands in a pattern that resembled malignant phyllodes tumors of the mammary gland (3 cases) or of purely stromal elements (1 case). Positive immunohistochemical reactions were noted using vimentin in 9 of 9 cases, CD34 in 8 of 8, HHF-35 in 2 of 8, smooth muscle actin in 3 of 9, desmin in 4 of 8, S-100 protein in 0 of 9, estrogen receptor in 1 of 7, and progesterone receptor in 6 of 7. None of the cases classified as PSS were positive for HHF-35, smooth muscle actin, or desmin. Of the 13 patients classified as having PSPUMP who did not undergo definitive local therapy at the time of diagnosis, recurrent signs or symptoms were seen in six (46%), necessitating additional therapy. Distant metastases to lung and bone developed in one patient classified as having PSS. Clinical and pathologic findings in this patient suggested a progression from PSPUMP to PSS. We conclude that sarcomas and related proliferative lesions of the specialized prostatic stroma encompass a spectrum of histologic features and may be grouped into two clinicopathologic categories: PSPUMP and PSS. Based on their distinctive histologic appearance and immunohistochemical profile, PSPUMP and PSS can be differentiated from other mesenchymal lesions of the prostate.     

Regulation of amyloid precursor protein cleavage

Multiple lines of evidence suggest that increased production and/or deposition of the beta-amyloid peptide, derived from the amyloid precursor protein, contributes to Alzheimer's disease. A growing list of neurotransmitters, growth factors, cytokines, and hormones have been shown to regulate amyloid precursor protein processing. Although traditionally thought to be mediated by activation of protein kinase C, recent data have implicated other signaling mechanisms in the regulation of this process. Moreover, novel mechanisms of regulation involving cholesterol-, apolipoprotein E-, and stress-activated pathways have been identified. As the phenotypic changes associated with Alzheimer's disease encompass many of these signaling systems, it is relevant to determine how altered cell signaling may be contributing to increasing brain amyloid burden. We review the myriad ways in which first messengers regulate amyloid precursor protein catabolism as well as the signal transduction cascades that give rise to these effects.     

Reconstitution of hyperacetylated, DNase I-sensitive chromatin characterized by high conformational flexibility of nucleosomal DNA

The normal pancreatic beta-cell population exhibits intercellular differences in its responsiveness to glucose. This cellular heterogeneity allows glucose to regulate, in a dose-dependent manner, total rates of insulin synthesis and release. It may also predispose to intercellular differences in susceptibility to dysregulating agents. The present study examines whether this is the case for interleukin 1beta (IL-1beta), which is known to suppress glucose-induced insulin synthesis and release. The effects of the cytokine were compared on beta-cell subpopulations with, respectively, high and low sensitivity to glucose. These subpopulations were separated on the basis of differences in the cellular metabolic responsiveness to an intermediate glucose concentration (7.5 mmol/liter) and then cultured for 20 h at 5 or 20 mmol/liter with or without IL-1beta. The suppressive action of IL-1beta (0.1 ng/ml) occurred predominantly in glucose-activated beta cells, reducing their high rates of insulin synthesis and release by more than 80%. Glucose-unresponsive cells became subject to a similar inhibition after their activation during culture at 20 mmol/liter glucose. On the other hand, IL-1beta induced or enhanced the expression of several noninsulin proteins in both subpopulations. The IL-1beta-stimulated expression of inducible nitric oxide synthase (iNOS) and heat shock protein 70 was more marked in the glucose-responsive subpopulation; that of heme oxygenase and Mn superoxide dismutase was comparable in the two subpopulations. Exposure to IL-1beta resulted in 10-fold higher medium nitrite levels in both subpopulations; this effect was prevented by the iNOS blocker, N(G)-methyl-L-arginine, which also prevented the IL-1beta-induced suppression in the glucose-responsive subpopulation. This study demonstrates that the cellular heterogeneity in glucose responsiveness predisposes to intercellular differences in the IL-1-induced suppression of insulin synthesis and release. While the cytokine induces the expression of noninsulin proteins such as iNOS in both glucose responsive and unresponsive cells, the subsequent nitric oxide production appears to predominantly affect glucose-stimulated functions in the glucose-activated cells.     

The scope and limitations of the reaction of delta 5-steroids with mercury(II) trifluoroacetate

The effect of the C-3 substituent on the reaction of androst-5-enes with mercury(II) trifluoroacetate in dichloromethane (modified Treibs oxidation) was investigated. 3 beta-Acyloxyandrost-5-en-17-ones gave 3 beta-acyloxy-6 beta-hydroxyandrost-4-en-17-ones accompanied by 3 beta-acyloxy-6-chloromercuriandrost-5-en-17-ones. 3 beta-Acetoxy-6 beta-trifluoroacetoxyandrost-4-en-17-one and 3 beta-acetoxy-4 beta-trifluoroacetoxyandrost-5-en-17-one were revealed to be intermediates in the reaction. The formation of the chloromercury steroids indicated participation in the reaction by the solvent. With 3 alpha-acetoxyandrost-5-en-17-one as substrate, a complete reversal in the product distribution was observed. 3 beta-Haloandrost-5-en-17-ones gave mainly products that reflected SN1 substitution of the halide. 3 beta-Hydroxy- and 3 beta-trifluoroacetoxyandrost-5-en-17-ones were formed. 3 beta-Methoxyandrost-5-en-17-one afforded in nearly identical yields androst-4-ene-3,17-dione, 3 beta-methoxy-6 beta-hydroxyandrost-4-en-17-one, 3 beta-methoxy-6-chloromercuriandrost-5-en-17-one and 6 beta-hydroxyandrost-4-ene-3,17-dione while androst-5-en-17-one yielded 3 beta,6 beta-dihydroxyandrost-4-en-17-one, androst-5-ene-7,17-dione and androst-4-ene-3,17-dione. The effects of solvent and other mercury salts on the reaction were also studied. Treibs oxidation was successful in chloroform, carbon tetrachloride, and dibromomethane, but not in other solvents tested. 3 beta-Acetoxy-6-bromomercuriandrost-5-en-17-one was obtained in dibromomethane. Replacement of the reagent by mercury(II) trichloroacetate altered the intermediates formed but not the products. Mercury(II) tribromoacetate was unreactive, however.     

Involvement of apoptosis in 4-vinylcyclohexene diepoxide-induced ovotoxicity in rats

Previous studies have determined that 4-vinylcyclohexene diepoxide (VCD) causes specific destruction of oocytes contained in small pre-antral (primordial and primary) ovarian follicles of Fischer 344 rats following 30 days of daily dosing with VCD. The purposes of this study were to identify the type of VCD-induced cell death occurring in small pre-antral follicles and to determine the earliest time following the onset of dosing when evidence of follicular destruction could first be detected. A significant decrease in the number of oocytes contained in small pre-antral follicles in ovaries of rats after 15 days of daily dosing (ip) with VCD (80 mg/kg) had been observed in preliminary experiments. Therefore, a study was conducted to determine the time of the onset of this follicular destruction by examination of follicular DNA integrity. Female Fischer 344 rats were dosed daily (80 mg/kg, i.p.) for 6, 8, 10, 12, or 14 days, and ovaries were removed 1, 4, or 24 hr after the final dose. Small pre-antral follicles (25-100 microns) were isolated by gentle dissociation of ovaries with collagenase, and follicles were sorted with micropipets. Genomic DNA was isolated from follicles and radiolabeled with [32P]dideoxy ATP, and the degree of fragmentation quantified by agarose gel electrophoresis and autoradiography. Degradation of DNA was evaluated by 32P content in low-molecular-weight fragments ( < 4 kilobase pairs). Degradation of DNA was not observed in follicles collected 24 hr after the final dose on any day. However, a random pattern of DNA degradation was observed, and was significantly greater (p < 0.05) compared with controls, when follicles were collected 4 hr following VCD administration on Days 10 and 12, but not on Days 6 or 8, of dosing. Although not significant, there was also evidence of DNA degradation in dosed animals on Day 14. Histological evaluation of small pre-antral follicles in ovarian sections during the early stages of VCD-induced DNA degradation (Day 10; 4 hr) demonstrated margination of chromatin along the nuclear membrane in oocytes and disruptions in focal contact between granulosa cells and oocytes, both features indicative of apoptosis. Furthermore, there was no sign of ruptured membranes in granulosa cells or oocytes or of an inflammatory response, characteristics of necrosis (pathological cell death). Whereas biochemical and morphological evidence of follicular destruction was seen 4 hr after dosing on Day 10, numbers of oocyte-containing primordial and primary follicles in VCD-treated animals were not different from controls at that time. These results demonstrate that the initial evidence of impending destruction of small pre-antral follicles is first consistently visualized following 10 days of daily dosing with VCD, although a measurable reduction in oocyte numbers has not yet occurred. Despite the fact that internucleosomal cleavage of genomic DNA was not observed, morphological evaluations support that granulosa cells and oocytes in primordial and primary follicles are destroyed via the induction of apoptosis.