Ten points to ponder in picking an oscilloscope

Like microscopes for biologists, oscilloscopes serve electrical engineers as a second pair of eyes, often providing the only way to “see” what they are working on. Selecting the right one for the job is therefore worth taking some care over. While it is tempting simply to purchase the same model you've used before, you may then miss out on one or more of the many useful features and capabilities that scope manufacturers add to their products with each generation. This article is intended to speed and rationalize the selection process and to guide electrical engineers around some common pitfalls. It provides guidelines under which scopes of all manufacturers may be evaluated objectively     

Pharmacokinetics of the protease inhibitor KNI-272 in plasma and cerebrospinal fluid in nonhuman primates after intravenous dosing and in human immunodeficiency virus-infected children after intravenous and oral dosing

The aim of this study was to evaluate the feasibility of routine falloposcopy in infertile patients undergoing basic infertility investigations, and to determine its usefulness in comparison with other tubal investigation methods. Seventy-five infertile women were selected based on the following criteria: 2 years of infertility, age between 18 and 40 years, normal ovulation, and partner with normal spermatozoa. Based on the results of the classical means of tubal evaluation (hysterosalpingography and laparoscopy), these patients were classified in one of two groups: tubal or unexplained infertility. All patients underwent a falloposcopy under general anaesthesia. The procedures were performed by the same surgeon with the linear everting catheter. Based on the falloposcopic findings, these patients were then reclassified in one of two other groups: falloposcopic tubal or falloposcopic unexplained infertility. The mean outcome measures were catheterization rate, duration of the procedure, pregnancy rates, complication rate and predictive value of Falloposcopy. The tubal catheterization rate was 94.5%. The mean duration of falloposcopy was 19 min per tube. Based on a standard scoring system, the spontaneous pregnancy rates were 27.6% for a score <20; 11.5% for a score between 21 and 30; and 0% if the score was >30. Complication rate was 5.1% of pinpoint perforations of the tube. With Cox's statistical model, none of the parameters analysed was statistically predictive of intrauterine pregnancy. We conclude that the greater accuracy of diagnosis by falloposcopy may indicate that it should be incorporated into the initial screening of infertile patients.     

Use of metronidazole in equine acute idiopathic toxaemic colitis

Sixteen cases of acute idiopathic toxaemic colitis developed in a veterinary hospital over a period of three years. Before the onset of colitis, 15 horses had received antibiotics, 11 had undergone general anaesthesia and various surgical procedures, and 10 had been treated with non-steroidal anti-inflammatory drugs. The horses had acute onset, profuse watery diarrhoea, profound depression, mild to moderate abdominal pain, reduced intestinal borborygmi, tachycardia, dehydration and endotoxic shock. Leucopenia, neutropenia and pyrexia were common early indicators of impending colitis. Metronidazole appeared to be an effective treatment; eight horses treated with metronidazole survived whereas five of seven horses that received other treatments, but no metronidazole, died or had to be euthanased. The aetiology of the colitis could not be determined, but the clinicopathological features resembled those of colitis attributed to an intestinal overgrowth of Clostridium perfringens type A. No Salmonella species were isolated from 52 samples of faeces, colonic contents and colonic mucosa which were collected from the horses antemortem and postmortem.     

Toward Secure Routing Infrastructures

The protocols, data, and algorithms that compute paths through interconnected network devices are possibly the most vital, complex, and fragile components in the global information infrastructure. They are also the least protected. This article examines the current state of, and practical prospects for, security in IP routing infrastructures     

Predictors of patients remaining anovulatory during clomiphene citrate induction of ovulation in normogonadotropic oligoamenorrheic infertility

The diagnostic criteria used to identify patients suffering from polycystic ovary syndrome remain controversial. The present prospective longitudinal follow-up study was designed to identify whether certain criteria assessed during standardized initial screening could predict the response to ovulation induction with clomiphene citrate (CC) in 201 patients presenting with oligomenorrhea or amenorrhea and infertility. Serum FSH levels were within the normal range (1-10 IU/L), and all patients underwent spontaneous or progestin-induced withdrawal bleeding. Initial CC doses were 50 mg daily for 5 days starting on cycle day 3. In the case of an absent response, doses were increased to 100 and 150 mg daily in subsequent cycles. First ovulation with CC was used as the end point. After a complete follow-up (in the case of a nonresponse, at least 3 treatment cycles with daily CC doses up to 150 mg), 156 patients (78%) ovulated. The free androgen index (FAI = testosterone/sex hormone-binding globulin ratio), body mass index (BMI), cycle history (oligomenorrhea vs. amenorrhea), serum androgen (testosterone and/or androstenedione) levels, and mean ovarian volume assessed by transvaginal sonography were all significantly different (P < 0.01) in responders from those in nonresponders. FAI was chosen to be the best predictor in univariate analysis. The area under the receiver operating characteristics curve in a multivariate prediction model including FAI, BMI, cycle history, and mean ovarian volume was 0.82. Patients whose ovaries are less likely to respond to stimulation by FSH due to CC treatment can be predicted on the basis of initial screening characteristics, such as FAI, BMI, cycle history (oligomenorrhea or amenorrhea), and mean ovarian volume. These observations may add to ongoing discussion regarding etiological factors involved in ovarian dysfunction in these patients and classification of normogonadotropic anovulatory infertile women.     

Influence of gender on the pharmacokinetics and pharmacodynamics of drugs

Historically, women, the elderly, and minorities were underrepresented in clinical drug trials. Information on possible gender-related differences in the pharmacokinetics of drugs is often lacking, although for some drugs significant differences could be demonstrated. In women, absorption, protein binding, volume of distribution, and metabolism of drugs may differ due to hormonal influences on physiological functions. Sex-related differences could be shown for phase I (cytochrome P450) as well as phase II (especially glucuronidation) reactions. Since many women world-wide take oral contraceptives, data should be provided to determine to what extent other drugs are influenced by estrogens and progestogens or to what extent the other drugs may attenuate the contraceptive efficacy. Moreover, estrogens interact with various enzymes and receptors, e.g. at the endothelial function as well as dopaminergic receptor sites, and may therefore attenuate or enhance drug effects or even drug side-effects. For a number of drugs it is well recognized, that women suffer more frequently from side-effects, however, it is often not clear, if this is due to gender differences in the pharmacokinetics or pharmacodynamics of the responsible drug. Very little is known about these gender-related differences and the possibility that women may show a different pattern of treatment response than men. As a result, drug approval authorities now require more data on the pharmacokinetics of novel drugs in women as well as a sufficient accrual of women in efficacy and outcome trials.