Purification and characterization of a Na+, K+ ATPase inhibitor found in an endotoxin of Leptospira interrogans

We showed previously that the glycolipoprotein fraction prepared from Leptospira interrogans inhibited the Na+,K+ ATPase enzyme purified from brain or kidney and in isolated nephron segments (M. Younes-Ibrahim, P. Burth, M. V. Castro Faria, B. Buffin-Meyer, S. Marsy, C. Barlet-Bas, L. Cheval, and A. Doucet, C. R. Acad. Sci. Paris Ser. III 318:619-625, 1995). In the present communication, we have demonstrated that unsaturated fatty acids such as oleic and palmitoleic acids, which are adsorbed to this fraction, are effective inhibitors of the enzyme.     

Chlamydia trachomatis screening in the adolescent population

1. The reproducibility of measurements of the arterial wall thickness in both the carotid and femoral artery was investigated by means of high-resolution B-mode ultrasonography. For this purpose, subjects with normal and increased intima-media thickness were selected. Images were stored on an optical disk and were analysed with a semi-automatic software program by two readers. Individuals were scanned twice by two independent observers. 2. Measurements were performed of the far and near wall of the common carotid artery and bulbous in 30 healthy subjects and 19 patients known to have an increased intima-media thickness. Far-wall measurements were made of the internal carotid artery on both sides and common femoral artery on the right side only. 3. In healthy subjects the mean within-observer coefficient of variation was 1.8% and 3.0% for the far wall in the common carotid artery on the right side and left side, respectively. For the near wall the mean coefficient of variation of the common carotid artery was 2.8% on the right and 3.4% on the left side. The mean coefficient of variation was less than 4% for both far and near wall in the bulbous and far wall in the internal carotid artery. Even in patients with increased intima-media thickness the mean coefficient of variation of each segment was less than 4.5%. In the control subjects the between-observer coefficient of variation of the common carotid artery was 2.8% and 5.1% for the far wall on the right and left side, respectively, and 3.4% and 4.2% for the near wall on the right and left side. In healthy subjects a mean difference of 0.002 mm within observers was found in the right far-wall common carotid artery, with limits of agreement of -0.048 to 0.052 mm. The coefficient of repeatability was 0.050 mm. For patients with increased intima-media thickness the mean difference in this segment was -0.006 mm (-0.094 to 0.082) with a coefficient of repeatability of 0.088 mm. For the near wall in the common carotid artery and far and near wall in the bulbous and internal carotid artery the mean differences were larger, but were all below 0.1 mm. The differences and limits of agreements increased between observers. In patients the between-observer mean difference of the far wall of the common carotid artery was -0.055 mm (-0.255 to 0.145). For the common femoral artery of normal control subjects the within- and between-observer mean differences were 0.005 mm (-0.119 to 0.129) and 0.015 mm (-0.081 to 0.111), respectively. 4. In conclusion, the reproducibility of intima-media thickness measurements in the common carotid artery is reliable, even in patients with increased artery wall thickness. Also in other segments prone to atherosclerosis, such as the bulbous, internal carotid artery and common femoral artery, a good reproducibility was found. To obtain good reproducibility it is highly recommended to use the same ultrasonographer to scan patients in follow-up studies.     

Annotated bibliography: studies evaluating decision-support interventions for patients

As the size of the older population grows and mortality rates continue to decline, an unprecedented number of women will live to very old age. Recent research has provided a better understanding of the impact of disability in the older population, risk factors for disability, and the consequences of disability. Older women have consistently been found to have higher prevalence rates of disability than men of the same age. This difference does not result from women developing disability more often than men, but rather surviving longer with their disabilities. This effect may be explained at least in part by the differences in the diseases underlying disability in older women and men. Interventions that can reduce the burden of disability in the aging population are now being explored. In the next century, it will be increasingly important to develop new prevention and treatment strategies that address the functional consequences of chronic disease in the population of women living to older and older ages.     

gamma-Aminobutyric acid (GABA) induces the acrosome reaction in human spermatozoa

The type and distribution of keratins (K) in malignant tumors of eyelids were examined immunohistochemically to understand the pathomechanism of intercellular interactions. All of the tumor cells in the basal cell carcinoma were positive for K14, which is specific for basal cells, whereas all of them were negative for K10, which is specific for suprabasal layers in stratified squamous epithelia. These findings suggest that basal cell carcinoma may consist of uniform, basal cell-like tumor cells. On the other hand, the squamous cell carcinoma and sebaceous carcinoma, which were positive for either K14 or K10 to varying extent, may consist of various tumor cells with different types and degrees of differentiation. In these tumors, K14 was frequently detected throughout the border cells of the tumor mass. Apoptotic bodies were detected at the region where this continuous distribution of K14 was interrupted. These findings may help to clarify the pathomechanism of the interactions between the tumor cells and stromal cells.     

Data sources for pharmacoeconomic and health services research

Different types of databases available for health-related research, the data contained in these databases, and potential applications for pharmacists or researchers are discussed. Case studies that demonstrate uses for health databases are presented. Databases can be organized by facility, by health care provider, by disease or organ, or by sector. The types of data they contain include financial data, utilization data, demographic data, and outcomes data. Data can be obtained from the public sector, the private sector, or the researcher's own health system. The costs and time associated with using existing databases are often less than those required to collect data, but the quality and accessibility of the data must also be considered. The researcher's choice of database will depend on the research question. Health care databases can be used for health management and decision-making, quality review and evaluation, outcomes research, episode-of-illness studies, and evaluation of treatment protocols. Researchers must comply with patient-confidentiality and other agreements when accessing data. The format of the data needs to be matched with the hardware and software to be used in the analysis, and the data need to be loaded, verified, and cleaned before use. In deciding which of the many available data sources to use, researchers must determine the appropriate balance between external data and data available within their own health systems. The decision on whether to use existing data sources or to collect data prospectively will depend on the research question, the available resources, and the scope of the study.     

Clinical observation of the temporal association between crack cocaine and duodenal ulcer perforation

HYPOTHESIS: To determine if a cause-effect relationship exists between crack cocaine use and duodenal ulcer perforation (DUP). PATIENTS AND METHODS: A retrospective study was conducted of all patients undergoing emergency surgical management for peptic ulcer disease over a 6-year period at a large inner-city municipal teaching hospital. The hospital records of 78 consecutive patients presenting with complications of peptic ulcer disease between April 1990 and April 1996 were reviewed. Group A (n = 24) consisted of patients with confirmation of crack cocaine usage within 8 hours of clinical presentation; group B (n = 54) consisted of patients with no antecedent history of crack cocaine use. Demographic data, timing of drug use, clinical presentation, laboratory and radiographic findings, toxicology screening, operative findings, and postoperative course were compared between the two groups. RESULTS: Both groups revealed a similar gender distribution, tobacco use, prior peptic ulcer symptoms, and laboratory findings. Group A patients were younger (t test, P = 0.01) and more likely to present with perforation, whereas patients in group B presented with a combination of symptoms (chi square, P = 0.03). Duodenal ulcer perforation was present in 75% of patients in group A compared with 46% of patients in group B (chi square, P = 0.04). Group B patients had a significantly longer hospital stay compared with those in group A (t test, P = 0.01). Both crack cocaine and alcohol are independent predictors of duodenal ulcer perforation. CONCLUSIONS: Patients with recent use of crack cocaine and/or alcohol are more likely to present with duodenal perforations. Although a temporal association between crack cocaine use and duodenal ulcer perforation was demonstrated, this study does not confirm a cause-effect relationship. A prospective cohort study is needed to clarify the pathogenesis of this potential cause-effect relationship.     

Involvement of pre- and postsynaptic mechanisms in posttetanic potentiation at Aplysia synapses

Posttetanic potentiation (PTP) is a common form of short-term synaptic plasticity that is generally thought to be entirely presynaptic. Consistent with that idea, PTP of evoked excitatory postsynaptic potentials at Aplysia sensory-motor neuron synapses in cell culture was reduced by presynaptic injection of a slow calcium chelator and was accompanied by an increase in the frequency but not the amplitude of spontaneous excitatory postsynaptic potentials. However, PTP was also reduced by postsynaptic injection of a rapid calcium chelator or postsynaptic hyperpolarization. Thus, PTP at these synapses is likely to involve a postsynaptic induction mechanism in addition to the known presynaptic mechanisms.