Delivery of dehydroepiandrosterone to premenopausal women: effects of micronization and nonoral administration

Previous molecular mechanics calculations suggest that strands of peptide nucleic acids (PNAs) and complementary oligonucleotides form antiparallel duplexes stabilized by interresidue hydrogen bonds. In the computed structures, the amide carbonyl oxygen nearest the nucleobase (O7') forms an interresidue hydrogen bond with the backbone amide proton of the following residue, (n + 1)H1'. Of the 10 published two dimensional 1H NMR structures of a hexameric PNA.RNA heteroduplex. PNA(GAACTC).r(GAGUUC), 9 exhibit two to five potential interresidue hydrogen bonds. In our minimized average structure, created from the coordinates of these 10 NMR structures, three of the five possible interresidue hydrogen bond sites within the PNA backbone display the carbonyl oxygen (O7') and the amide proton (n + 1)H1' distances and N1'-H1'-(n - 1)O7' angles optimal for hydrogen bond formation. The finding of these interresidue hydrogen bonds supports the results of our previous molecular mechanics calculations.     

Micropipette manipulation technique for the monitoring of pH-dependent membrane lysis as induced by the fusion peptide of influenza virus

We have assembled a micropipette aspiration assay to measure membrane destabilization events in which large (20-30 microns diameter) unilamellar vesicles are manipulated and exposed to membrane destabilizing agents. Single events can be seen with a light microscope and are recorded using both a video camera and a photomultiplier tube. We have performed experiments with a wild-type fusion peptide from influenza virus (X31) and found that it induces pH-dependent, stochastic lysis of large unilamellar vesicles. The rate and extent of lysis are both maximum at pH 5; the maximum rate of lysis is 0.018 s-1 at pH 5. An analysis of our data indicates that the lysis is not correlated either to the size of the vesicles or to the tension created in the vesicle membranes by aspiration.     

Reoperations of the extrahepatic bile ducts

The results of reoperations on the extrahepatic bile ducts in 82 patient s performed, mainly, for undetected and uncorrigated changes in the extrahepatic bile ducts caused by diagnostic, tactical and technical errors made during the first operation are presented.     

Retrospective analysis of alternate-day prednisone maintenance therapy for Crohn''s disease

INTRODUCTION: Clinical, microbiological, therapeutic and prognostic characteristics of brain abscesses were analyzed as well as the influence of CT in their evolution. MATERIALS AND METHODS: Retrospective study of 59 patients with the diagnosis of brain abscess of bacterial source before (group A) and after (group B) the introduction of CT (25 and 34 patients, respectively). RESULTS: The most common symptom was headache (76.3%) and the most common abnormality in physical examination was a decrease in the level of consciousness (61%) and this abnormality was associated with a higher mortality rate (13% versus 41.6%; p < 0.05) and also a higher proportion of neurologic sequelae (50% versus 85.7%; p < 0.05). The diagnosis was obtained earlier in group B. The hematogenous source predominated (32.2%); an adjacent source was identified in 28.8% and an apparent source was not recognized in 27.2% (40% in group A versus 17.6% in group B). Anaerobic and microaerophilic streptococci were the bacteria recovered most frequently. Gram-negative aerobic bacteria were the most common in otogenic abscesses. The use of corticosteroids had no influence upon mortality, but it was associated with a lower percentage of neurological sequelae (40% versus 14%; p < 0.05). The introduction of CT decreased mortality (40% in group A versus 23.5% in group B, although this difference was not significant) and also sequelae (86.6% in group A versus 57.6% in group B; p < 0.05). Leaving apart cases of bacterial endocarditis, in which death was due to the underlying heart disease and a systemic sepsis picture, mortality attributed to brain abscess was 20.3%. CONCLUSIONS: The introduction of CT has meant a significant breakthrough for the diagnosis, treatment and follow-up of these patients and has contributed to improvement in survival. In our series, the diagnosis of brain abscess was obtained earlier and the number of brain abscesses with no apparent source has decreased since the introduction of CT. Moreover, CT sensitivity is really good for locating multiple abscesses. Overall, the prognosis of these patients has improved since the introduction of this technique. Nevertheless, brain abscess is still associated with a relevant morbi-mortality rate.     

Validation of dietary intakes of protein and energy against 24 hour urinary N and DLW energy expenditure in middle-aged women, retired men and post-obese subjects: comparisons with validation against presumed energy requirements

OBJECTIVES: To compare validation of reported dietary intakes from weighed records against urinary nitrogen excretion and energy expenditure measured by DLW, and to examine the utility of the Goldberg cut-off for EI:BMR in the identification of under-reporters. DESIGN: Energy (EI) and nitrogen (protein) intake (NI) were measured by 16 d of weighed diet records collected over 1 y. They were validated against urinary nitrogen excretion in 5-8 (mean 6.0) 24 h urine collections and total energy expenditure (EE) measured by doubly labelled water (DLW). Basal metabolic rate (BMR) as measured by whole body calorimetry in women or bedside ventilated hood (Deltatrac) in men. Individual subjects were identified as under-reporters if Urine N:NI was > 1.00 or if EI:EE was < 0.79. The agreement between the two ratios in detecting under-reporting was examined. The results from the direct validation by DLW were also compared with validation using the Goldberg cut-off for EI:BMR (Goldberg et al, 1991). SUBJECTS: Eighteen women aged 50-65 y and 27 men aged 55-87 y were selected from participants in two larger dietary surveys as representing the full range of dietary reporting as measured by Urine N:NI. Data from a previous study of 11 post-obese subjects were also included. RESULTS: The two ratios, Urine N:NI and EI:EE, were significantly related (r = -0.48, P < 0.01). Using the above cut-offs, seven (4F, 3M) subjects were identified as under-reporters by both methods, one (1M) by Urine N:NI only and 8 (3F, 5M) by EI:EE only. There was close agreement in post-obese subjects where 6 subjects showed a substantial degree of under-reporting by both methods (r = -0.87, P < 0.001). The correlation between direct validation by DLW and EI:BMRest was 0.65 (P < 0.001). Some limitations of the Goldberg cut-off for identifying individual under-reporters were demonstrated. CONCLUSIONS: EI:EE provides an estimate of the degree of under-reporting of energy at the group and individual level. Urine N:NI identifies under-reporting of protein intake and the most obvious under-reporters of energy, but is probably of lesser value in estimating the overall degree of under-reporting of energy at group level. Good validation by EI:BMR depends on knowledge of physical activity at both group and individual level. However, the correlation of 0.65 between EI:EE and EI:BMRest suggests that EI:BMR could be usefully incorporated into analysis of data from epidemiological studies. Validation measures consisting of at least predicted EI:BMR ratios and urinary measures should be incorporated into dietary surveys. SPONSORSHIP: This work was funded by the Ministry of Agriculture Fisheries and Food, the Medical Research Council, the Cancer Research Council and the Swedish Medical Research Council and the Henning and Johan Throne-Holst Foundation.