Mechanical properties of human saphenous veins from normotensive and hypertensive patients

The three-dimensional structure of a synthetic peptide corresponding to the putative transmembrane segment M3 (amino acid residues 277-301) of the alpha subunit of the nicotinic acetylcholine receptor from Torpedo californica has been studied by means of two-dimensional 1H-NMR spectroscopy in a chloroform/methanol (1:1) mixture containing 0.1 M LiClO4. Complete resonance assignment has been performed using double-quantum-filtered COSY (DQF-COSY), TOCSY and NOESY spectra. The spatial structure has been calculated using the Diana program on the basis of integrated intensities of NOESY spectra. HN-C(alpha)H and HC(alpha)-C(beta)H spin-spin coupling constants. Residues 279-297 of M3 form a right-handed helix (root mean square deviation is 0.032 nm for backbone atoms and 0.088 nm for all heavy atoms). The conformations of the 17 side chains have been unambiguously determined. The obtained structure is in accord with the photolabeling pattern of the membrane nicotinic acetylcholine receptor (nAChR) which suggests alpha-helical structure of M3 in the labeled portion [Blanton, M. P. & Cohen, J. B. (1994) Biochemistry 33, 2859-2872].     

Evaluation and characterization of micronuclei in early spermatids of mice exposed to 1,3-butadiene

The 18S rRNA gene (Rns) phylogeny of Acanthamoeba is being investigated as a basis for improvements in the nomenclature and taxonomy of the genus. We previously analyzed Rns sequences from 18 isolates from morphological groups 2 and 3 and found that they fell into four distinct evolutionary lineages we called sequence types T1-T4. Here, we analyzed sequences from 53 isolates representing 16 species and including 35 new strains. Eight additional lineages (sequence types T5-T12) were identified. Four of the 12 sequence types included strains from more than one nominal species. Thus, sequence types could be equated with species in some cases or with complexes of closely related species in others. The largest complex, sequence type T4, which contained six closely related nominal species, included 24 of 25 keratitis isolates. Rns sequence variation was insufficient for full phylogenetic resolution of branching orders within this complex, but the mixing of species observed at terminal nodes confirmed that traditional classification of isolates has been inconsistent. One solution to this problem would be to equate sequence types and single species. Alternatively, additional molecular information will be required to reliably differentiate species within the complexes. Three sequence types of morphological group 1 species represented the earliest divergence in the history of the genus and, based on their genetic distinctiveness, are candidates for reclassification as one or more novel genera.     

Flavonol and chalcone ester glycosides from Bidens andicola

OBJECTIVES: To examine the effect of black race and acute (negative life events) and chronic (lack of social support) psychological stress on the risk of herpes zoster in late life. DESIGN: A population-based, prospective cohort study. SETTING: Central North Carolina. PARTICIPANTS: Duke Established Populations for Epidemiological Studies of the Elderly, a stratified probability sample of community-dwelling persons more than 65 years of age. MEASUREMENTS: Interviewers administered a comprehensive health survey to the participants in 1986-1987 (P1, n = 4162), 1989-1990 (P2, n = 3336), and 1992-1994 (P3, n = 2568). Incident cases of zoster between P1 and P2 and P2 and P3 served as the dependent variable. Hypothesis-testing variables included race, negative life events, and five measures of social support. Control variables included age, sex, education, cancer, chronic diseases, basic ADLs, instrumental ADLs, depression, self-rated health, hospitalization, and cigarette smoking. Statistical analyses employed chi-square tests and proportional hazards model. RESULTS: At baseline, the sample had a mean age of 73.6 years and was 55% black, 45% white, and 65% female. There were 65 cases of zoster between P1 and P2 and 102 cases of zoster between P2 and P3. From P1 to P2, 1.4% of blacks and 3.4% of whites developed zoster (P < .001). From P2 to P3, 2.9% of blacks and 7.5% of whites developed zoster (P < .001). After controlling for the above variables, blacks were significantly less likely to develop zoster (adjusted risk ratio = 0.35; 95% confidence interval (CI), 0.24-0.51; P < .001). Negative life events increased the risk of zoster, but the result was borderline for statistical significance (adjusted RR = 1.38, 95% CI 0.96-1.97; P = .078). No measures of social support were significantly associated with zoster. CONCLUSION: Black race decreased the risk of zoster in late life significantly. Measures of stress were not significantly related to zoster, but study limitations preclude definitive conclusions. Future research should focus on these factors in larger samples and different populations.     

Polymerized micelles. Fixation of micelle structure by the core cross-linking

Summary Polymerized micelles of poly(11-acryloylaminoundecanoic acid) were obtained via radical polymerization in micellar state. The structure of micelles was fixed by cross-linking of the micelle core using solubilized diacrylate co-monomer. Hydrodynamic behavior of both cross-linked and non cross-linked polymerized micelles was studied by means of viscometry.     

Early transoesophageal echocardiography in cryptogenic and lacunar stroke and transient ischaemic attack

OBJECTIVE: To determine, prospectively, the effect of clinical factors on the duration of frank haematuria and the incidence of clot retention after transurethral resection of the prostate (TURP). PATIENTS AND METHODS: Seventy-nine men who underwent TURP in a 3-month period were entered into this study, during which the time to cessation of bleeding and the occurrence of clot retention(s) were recorded over a 4-week period. The effect of other clinical factors (histology, weight of tissue resected. operative duration, grade of surgeon and resection rate) was also assessed. RESULTS: Gross haematuria ceased in 47%, 73%, 96%, and 97% of patients at the end of the first, second, third and fourth weeks, respectively. The duration of postoperative bleeding was significantly associated with the weight of tissue resected and the operation time (P<0.001 and <0.05, respectively). Furthermore, five patients were re-admitted with clot retention, but there was no significant correlation between the occurrence of this morbidity and any of the other indices. CONCLUSION: Postoperative bleeding usually stops within 3 weeks of TURP. This period, which is about half the time hitherto assumed, is directly related to the size of the gland resected and the duration of the procedure. However, the occurrence of clot retention is not significantly associated with the duration of haematuria or any of the other clinical factors evaluated. Thus, a high fluid intake is mandatory for 3 weeks after TURP, but men who continue to bleed should be advised to continue with a high-fluid regimen until their urine is clear.     

Striato-nigral degeneration. A propos of 2 anatomo-clinical cases

Two sporadic cases of striato-nigral degeneration were characterized by the onset at the age of 61 of an akinetic-hypertonic syndrome and of a minimal or absent rest tremor, with a pyramidal syndrome, sphincter disorders, dysphonia, difficulty in swallowing and an unfavorable development in the space of two or three years not affected by L-Dopa. In one case, total insomnia was demonstrated by means of 3 polygraphic recordings during the night, two of them consecutive, and aprobenecide test showed a definite fall in H.V.A. and 5 H.I.A.A. in the lumbar cerebrospinal fluid. Anatomical verification showed, in one case, isolated putamino-nigral degeneration, and in the other associated with lesions of the olivo-cerebellopontine system. Much of the excess pigmentation found only in the putamen was melanotic in character and resulted perhaps from the striato-nigral degeneration, making it possible to classify this more accurately among the other multisystem degenerations, especially olivo-ponto-cerebellar atrophy and Shy-Drager syndrome     

Delayed matching performance after visual Wulst lesions in pigeons.

Eight homing pigeons were trained preoperatively on a mixed delayed matching-to-sample (DMTS) task in which 6 different conditions were presented randomly: simultaneous matching and 0-, 1-, 2-, 4-, and 8-sec delays. Ss that sustained extensive or complete damage to the visual Wulst, a multilaminate region in the pigeon telencephalon which occupies the dorsal aspect of the cerebral hemisphere, and moderate damage to the hyperstriatum ventrale showed a decrease in accuracy of performance to chance levels in all of the delay conditions as well as in simultaneous matching. After extensive retraining on the 0-sec-delay matching alone, performance on 0-sec-delay and simultaneous matching, presented in mixed DMTS, improved to between 70 and 90% correct. However, performance on delay conditions remained at chance level. All but 1 S failed to show signs of postoperative improvement on delay problems in the course of the final testing. Data suggest that the conditional property of the task was a critical factor in the initial drop in accuracy on all of the presented problems. The relatively permanent loss of accuracy on all delay conditions is attributed mainly to the temporal separation of sample and comparison stimuli. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)