27-GHz bandwidth high-speed monolithic integrated optoelectronicphotoreceiver consisting of a waveguide fed photodiode and anInAlAs/InGaAs-HFET traveling wave amplifier

A monolithic integrated photoreceiver for 1.55-μm wavelength has been designed for operation in a 20-Gb/s synchronous digital hierarchy system (SDH/SONET), based on a new integration concept. The optoelectronic integrated circuit (OEIC) receiver combines a waveguide-integrated PIN-photodiode and a traveling wave amplifier in coplanar waveguide layout with four InAlAs/InGaAs/InP-HFETs (0.7-μm gate length). The receiver demonstrates a bandwidth of 27 GHz with a low frequency transimpedance of 40 dBΩ. This is, to our knowledge, the highest bandwidth ever reported for a monolithic integrated photoreceiver on InP. Furthermore, a receiver sensitivity of -12 dBm in the fiber (20 Gb/s, BER=10^-9) and an overall optical input dynamic range of 27 dB is achieved. Optical time domain multiplex (TDM) system experiments of the receiver packaged in a module show an excellently shaped eye pattern for 20 Gb/s and an overall sensitivity of -30.5 dBm (BER=10^-9) [including erbium doped fiber amplifiers (EDFA)]     

Contribution of plasminogen activators and their inhibitors to the survival prognosis of patients with Dukes' stage B and C colorectal cancer

Despite the advances in pre-, peri- and post-operative medical care of colorectal carcinoma patients, the prognosis has improved only marginally over recent decades. Thus, additional prognostic indicators would be of great clinical value to select patients for adjuvant therapy. In previous studies we found that colorectal carcinomas have a marked increase of the urokinase-type of plasminogen activator (u-PA), and the inhibitors PAI-1 and PAI-2, whereas the tissue-type plasminogen activator (t-PA) is found to be decreased in comparison with adjacent normal mucosa. In the present study we evaluated the prognostic value of several plasminogen activation parameters, determined in both normal and carcinomatous tissue from colorectal resection specimens, for overall survival of 136 Dukes' stage B and C colorectal cancer patients, in relation to major clinicopathological parameters. Uni- and multivariate analyses indicated that a high PAI-2 antigen level in carcinoma, a low t-PA activity and antigen level and a high u-PA/t-PA antigen ratio in adjacent normal mucosa are significantly associated with a poor overall survival. A high ratio of u-PA antigen in the carcinomas and t-PA antigen in normal mucosa, i.e. u-PA(C)/t-PA(N), was found to be predictive of a poor overall survival as well. All these parameters were found to be prognostically independent of the clinicopathological parameters. Multivariate analysis of combinations of these prognostically significant plasminogen activation parameters revealed that they are important independent prognostic indicators and have in fact a better prognostic value than their separate components. Based on these combined parameters, subgroups of patients with Dukes' stage B and C colorectal cancer could be identified as having either a high or a low risk regarding overall survival. In conclusion, these findings emphasize the relevance of the intestinal plasminogen activation system for survival prognosis of patients with colorectal cancer and, in the future, might constitute a patient selection criterion for adjuvant therapy.     

Obese gene expression: reduction by fasting and stimulation by insulin and glucose in lean mice, and persistent elevation in acquired (diet-induced) and genetic (yellow agouti) obesity

Mutations in the obese (ob) gene lead to obesity. This gene has been recently cloned, but the factors regulating its expression have not been elucidated. To address the regulation of the ob gene with regard to body weight and nutritional factors, Northern blot analysis was used to assess ob mRNA in adipose tissue from mice [lean, obese due to diet, or genetically (yellow agouti) obese] under different nutritional conditions. ob mRNA was elevated in both forms of obesity, compared to lean controls, correlated with elevations in plasma insulin and body weight, but not plasma glucose. In lean C57BL/6J mice, but not in mice with diet-induced obesity, ob mRNA decreased after a 48-hr fast. Similarly, in lean C57BL/6J controls, but not in obese yellow mice, i.p. glucose injection significantly increased ob mRNA. For up to 30 min after glucose injection, ob mRNA in lean mice significantly correlated with plasma glucose, but not with plasma insulin. In a separate study with only lean mice, ob mRNA was inhibited >90% by fasting, and elevated approximately 2-fold 30 min after i.p. injection of either glucose or insulin. These results suggest that in lean animals glucose and insulin enhance ob gene expression. In contrast to our results in lean mice, in obese animals ob mRNA is elevated and relatively insensitive to nutritional state, possibly due to chronic exposure to elevated plasma insulin and/or glucose.     

Universal precautions prevent hepatitis C virus transmission: a 54 month follow-up of the Belgian Multicenter Study. The Universitaires Cliniques St-Luc (UCL) Collaborative Group

The isolation of anti-hepatitis C virus (HCV) in hemodialyzed (HD) patients has been repeatedly advocated to prevent nosocomial HCV transmission. We evaluated the incidence of seroconversion for HCV in Belgian HD patients, and demonstrate the complete prevention of HCV transmission by adherence to the universal precautions advocated by the Centers for Disease Control (Atlanta, GA, USA). All (N = 963) HD patients from 15 units, none of which isolates anti-HCV positive patients, were tested by a second or third generation enzyme-linked immunosorbent assay (with confirmation by a second- or third-generation recombinant immunoblot assay or the polymerase chain reaction) every 18 months from May 1991 to November 1995. Follow-up was available in 488 patients (drop-outs resulting from death or transplantation mainly). The yearly incidence of seroconversion for HCV over the initial 18 months was 1.41%, with evidence suggestive of nosocomial HCV transmission. Universal precautions were therefore reinforced. The incidence of seroconversion subsequently fell to 0.56% and 0%, respectively (P = 0.014), despite the facts that the average transfusion load and the proportion of patients with dialyzer reuse or with monitors disinfected after each session did not change significantly. We conclude that the strict enforcement of universal precautions fully prevents HCV transmission to HD patients. The isolation of anti-HCV positive patients is not warranted.     

Quantitative analysis of microvascular changes in diffuse astrocytic neoplasms with increasing grade of malignancy

BACKGROUND: Despite concerns about its prevalence and ramifications, harassment has not been well quantified among physicians. Previous published studies have been small, have surveyed only 1 site or a convenience sample, and have suffered from selection bias. METHODS: Our database is the Women Physicians' Health Study, a large (4501 respondents; response rate, 59%), nationally distributed questionnaire study. We analyzed responses concerning gender-based and sexual harassment. RESULTS: Overall, 47.7% of women physicians reported ever experiencing gender-based harassment, and 36.9% reported sexual harassment. Harassment was more common while in medical school (31% of gender-based and 20% for sexual harassment) or during internship, residency, or fellowship (29% for gender-based and 19% for sexual harassment) than in practice (25% for gender-based and 11% for sexual harassment). Respondents more likely to report gender-based harassment were physicians who were now divorced or separated and those specializing in historically male specialties, whereas those of Asian and other (nonwhite, nonblack, non-Asian, non-Hispanic) ethnicity, those living in the East, and those self-characterized as politically very conservative were less likely to report gender-based harassment. Being younger, born in the United States, or divorced or separated were correlated with reporting ever experiencing sexual harassment; those who were Asian or who were currently working in group or government settings were less likely to report it. Those who felt in control of their work environments, were satisfied with their careers, and would choose again to become physicians reported lower prevalences of ever experiencing harassment. Those with histories of depression or suicide attempts were more likely to report ever having been harassed. CONCLUSIONS: Women physicians commonly perceive that they have been harassed. Experiences of and sensitivity to harassment differ among individuals, and there may be substantial professional and personal consequences of harassment. Since reported rates of sexual harassment are higher among younger physicians, the situation may not be improving.     

Pharmacotherapeutic compass 1998

The Central Medical Pharmaceutical Committee of the Health Insurance Council informs the medical profession annually about the effects of drugs through the Pharmacotherapeutical Compass. The 1998 edition now contains a chapter on pharmacokinetics as well. Compared with previous editions the main alterations of the contents concern an introduction and advice on the antidepressants, two protocols with respect to the medical treatment of patients suffering from epilepsy, advice with respect to oral drugs for the treatment of inflammatory bowel disease, an introduction and advice regarding the treatment of allergic rhinitis, the treatment of patients suffering from AIDS with antiretroviral drugs, the treatment of genital herpes, the taking of insulin lispro by patients with diabetes and the taking of bisphosphonates to prevent or to treat osteoporosis. Two corrections to the 1998 edition are given.     

The multifunctional regulatory proteins ABF1 and CPF1 are involved in the formation of a nuclease-hypersensitive region in the promoter of the QCR8 gene

The abundant DNA-binding proteins ABF1 and CPF1 are members of a family of global regulators with diverse chromosomal functions in the yeast Saccharomyces cerevisiae. Recent evidence suggests that these protein factors may be involved in establishing and maintaining well-defined chromatin structures in promoter regions and other genetic elements. We have investigated the involvement of ABF1 and CPF1 in chromatin organization at the QCR8 gene, encoding subunit VIII of the mitochondrial ubiquinol-cytochrome c oxidoreductase. The promoter region of the QCR8 gene contains overlapping binding sites for ABF1 and CPF1. Nucleosome positioning studies indicate that the QCR8 gene is associated with a phased array of nucleosomes under both catabolite-repressed and derepressed growth conditions. Analysis of binding site mutants reveals that both ABF1 and CPF1 are involved in maintaining a nuclease-hypersensitive region in the QCR8 promoter. The chromatin structure at QCR8 during steady-state growth is, however, mainly dependent on binding of ABF1 to the promoter region. Implications of these findings for the role played by ABF1 and CPF1 in the regulation of mitochondrial biogenesis and other processes important for cell growth and division will be discussed.     

Ambulatory urodynamics

Ambulatory monitoring of lower and upper urinary tract continues to develop. The addition of electronic urine-loss measurements to indicate the exact time-related loss is an important new feature. In the near future, quantitative urine-loss measurements will become available. The additional possibility of plugging in a flowmeter completes the technique with respect to pressure-flow analysis. At present, however, ambulatory urodynamics is still confined to specialized urodynamic centers. Ambulatory urodynamic monitoring has shown that de-novo detrusor instability after a suspension operation is frequently missed as a preoperative diagnosis of detrusor overactivity. The first steps are being taken toward giving a quantitative analysis of detrusor activity during the filling phase. This justifies a more widespread use of this ambulatory monitoring.