Severe and early alteration of action potential during acute cardiac rejection in rats

INTRODUCTION: Alteration of cardiac action potential and its adaptation to heart rate could contribute to cardiac dysfunction and arrhythmias during acute cardiac rejection. METHODS AND RESULTS: Heterotopic heart transplantation was performed in allogeneic and syngeneic rats in which the action potentials of right and left ventricles were measured at 1, 2.5, 3.3, and 5.7 Hz successively using standard microelectrode techniques and compared with nontransplanted hearts. For each frequency, we measured action potential amplitude, action potential duration, transmembrane resting potential, and Vmax. In the right ventricle, at 1 Hz in the presence of rejection (n = 40), a significant increase was observed in action potential duration at 20%, 50%, and 70% repolarization (82.5%, 75.6%, and 70.8%, respectively) and in action potential amplitude (+17.9 mV), and the resting potential was decreased (-5.3 mV). A lack of adaptation of action potential duration to the driving frequency was observed in the rejecting heart group in contrast to controls (n = 20) and nonrejecting hearts (n = 13). Similar results were observed in the left ventricle and surprisingly in the native hearts (n = 11) of recipients with allografted rejecting hearts in the abdominal position. CONCLUSION: Action potential and its adaptation to the driving frequency is considerably altered during acute rejection. A humoral factor could contribute to cardiac dysfunction.     

Response of large and small vessels to alpha and beta adrenoceptor stimulation in heart failure: effect of angiotensin converting enzyme inhibition

Understanding sexual fantasies is important to the scientific study of human sexuality. A sexual fantasy refers to a private or covert experience in which the imagination of desirable sexual activity with a partner is sexually arousing to the individual. Prior sexual experiences of an individual appear to increase the incidence of sexual fantasies, as well as the variety of sexual themes in a fantasy, which permit a greater elaboration of the fantasy theme when compared to less sexually experienced individuals. The present study was an investigation of the factors or sexual themes that emerge in a college male population, as well as a comparison of college men with human samples obtained in other studies: a sample of men and women and a sample of sexually variant men. In this study, 116 male students, all of whom identified themselves as heterosexual, completed the Wilson Sex Fantasy Questionnaire (WSFQ). Results indicated that the present sample had significantly more exploratory, intimate, impersonal, and total sexual fantasies than sexual fantasies reported by female respondents in another study using the WSFQ and significantly more intimate, impersonal, and total sexual fantasizing when compared with a male sample in another study. The men in this study also evidenced less deviant areas of sexual fantasizing when compared with a group of sexually variant men in another study. A principal components analysis extracted four factors, which accounted for 45% of the total variance. The four sexual fantasy topic areas for the most part replicated prior findings by Wilson (1988) but are also more heterogeneous, indicating that male college students engage in a variety of sexual fantasies but seem to favor more intimate, less deviant or exploratory sexual themes that are in line with nonclinical samples and different from several clinical samples of sexually variant men.     

Neurotransmitters in cerebrospinal fluid reflect pathological activity

Reduced bone mineral density (BMD), termed diabetic osteopenia, has been reported in patients with insulin-dependent (Type 1) diabetes mellitus (IDDM). To examine BMD in long-term IDDM patients with normal kidney function, but with different degrees of urinary albumin excretion rate (UAER), compared to that of patients with elevated plasma creatinine, 36 IDDM male patients (mean duration 27 years) were subdivided according to UAER (<30, 30-300, >300, >300 mg 24 h(-1) and plasma creatinine 0.120-0.350 mmol l(-1)) and 15 controls were recruited. BMD was measured by dual energy X-ray absorptiometry and UAER by enzyme linked immunosorbent assay. BMD was normal in IDDM patients with normal UAER and reduced in the femoral neck, the trochanter major, and the Wards triangle in patients with increased UAER (p < 0.01, p < 0.05, p < 0.02). BMD correlated to creatinine clearance in both cortical and cancellous bone sites (p < 0.001, p < 0.0001), and inversely to the levels of plasma PTH (p < 0.0005). We conclude that BMD is normal in long-term IDDM male patients with normal kidney function and normal UAER and reduced in patients with increased UAER. Diabetic osteopenia seems to be a progressive phenomenon related to diabetic nephropathy and associated with the decrease in creatinine clearance and with the resulting rise in plasma PTH.     

Diffuse peritoneal leiomyomatosis. A clinical case report

Leiomyomatosis peritonealis disseminata (LPD) is a rare condition characterized by numerous leiomyomas throughout the peritoneal cavity which appears grossly malignant but histologically benign. LPD occurs during reproductive age, especially the third and fourth decades. The etiology of the disorders is so far unknown, but presumedly hormonal. One case of LPD is presented and discussed. The patient, a 25-year-old nulliparous woman complained of aspecific colic type abdominal pain. Pelvic examination revealed a mass of about 4 x 5 cm occupying the cul de sac. Exploratory laparatomy revealed the mass and numerous nodules on the surface of the right ovary and of the omentum. After surgery no therapy was done and follow-up was done only by ultrasound. After 4 years follow-up the patient is well and is now pregnant at the XXV week of gestation. The number of cases of LPD documented in the literature to date is only about 50 cases, but they are likely to be much more, because of many asymptomatic cases. A conservative approach is recommended, but in the last years we have always had more reports of malignant degeneration (about 10%). So when surgical castration is not possible for age and or children desire, more aggressive follow-up should be recommended. In fact recidive is so far the most unfavourable prognostic factor.     

New ways to ventilate newborns in acute respiratory failure

Out treatment options for acute neonatal failure have expanded greatly in the last 20 to 30 years. This article reviews patient-triggered ventilation, high frequency ventilation, negative extrathoracic pressure ventilation, nitric oxide therapy, liquid ventilation, extracorporeal membrane oxygenation, and advances in pulmonary function monitoring. The authors present background theories, describe equipment, review clinical strategies, and the results of recent trials.     

Analysis of the oxidative catabolism of retinoic acid in rat Dunning R3327G prostate tumors

Transforming growth factor-beta (TGF-beta) is a pleiotropic regulatory factor of tissue remodeling. Angiogenesis, a prerequisite of tissue repair and tissue expansion, is induced by TGF-beta in vivo, while proliferation and migration of cultured endothelial cells are inhibited by TGF-beta. Indirect mechanisms stimulating angiogenesis and modification of TGF-beta effects by cell-matrix interaction have been postulated to account for this paradigm. Because cellular behavior in tissue remodeling is decisively determined by cell-matrix interactions, which in turn is mediated via integrins, we investigated the effect of TGF-beta on matrix-dependent endothelial cell functions. Integrin expression of human dermal microvascular endothelial cells (HDMEC) was measured by Northern blot and fluorescence-activated cell sorter analysis after TGF-beta treatment and correlated to cell-matrix interactions, which were studied in a colorimetric cell attachment assay as well as the Boyden chamber chemotaxis assay. We found a cell-specific downregulation of integrin expression in HDMEC on the level of mRNA as well as on the cell surface. This effect correlated well with the reduction of integrin-dependent cell adhesion to several matrix proteins, in particular to fibronectin. Moreover, TGF-beta decreased fibronectin-induced chemotaxis of HDMEC. Thus, TGF-beta controls cell-matrix interaction of HDMEC by down-regulation of integrin expression. This effect of TGF-beta reflects direct and cell-specific control mechanisms on microvascular cells that may be critical for the coordinated process of angiogenesis requiring a balance of stimulatory and inhibitory factors.     

Modulators of prostaglandin E2 synthesis in human amnion

OBJECTIVE: The purpose of these studies was to determine the effects of the essential fatty acid, linoleic acid, and the commonly used non-steroidal anti-inflammatory agents, aspirin and acetaminophen, on the rate of prostaglandin (PG) biosynthesis by human amnion cells. METHODS: Amnion cells were isolated from term, normal pregnancies and grown to confluence. Cells were incubated with control or medium containing 100 mumol/L linoleic acid. Cells were also incubated with control medium or medium containing 10 or 100 micrograms/mL aspirin or acetaminophen. RESULTS: Following an initial delay, amnion cells exposed to linoleic acid exhibited a significant increase in PGE synthesis. Both aspirin and acetaminophen in clinically relevant concentrations had a significant inhibitory effect on amnion cell PGE synthesis. CONCLUSIONS: Linoleic acid has a stimulatory effect and aspirin and acetaminophen have an inhibitory effect on PGE synthesis in human amnion cells in culture. We speculate that dietary habits, supplement ingestion, and over-the-counter drug use may affect amnion cell PG production. In view of the potential importance of intrauterine PG production in normal and abnormal labor, further study in this area is indicated.     

Adult vaccination

Experience with a urological waiting list initiative is presented, wherein a list of 231 non-urgent cases was cleared over a 5 month period by a single operator. Some patients had waited 10 years for surgery. Following a postal request, the waiting list was validated; 31.2% of patients wished to be removed. The remaining 68.8% desired surgery and consisted of 51 requiring minor surgical procedures and 108 who needed more major surgery mostly for the relief of bladder outflow obstruction. Minor cases received dates for surgery; however, only 68.2% of this group attended despite being given more than one date for admission. Major cases were reviewed in a pre-admission clinic. General and urological condition was assessed, improved where necessary and surgery booked or delayed accordingly. A small number of patients did not attend or only attended to be reassured that surgery was not needed. Following clinical review, 18.5% of this group did not require operation. The long urological waiting list is a unique situation where patients listed may no longer require surgery. Reviewing these patients not only reduces numbers but also markedly increases percentage attendance for surgery.