Results of a search for double positron decay and electron-positron conversion of 78Kr.
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Journal Article↗
Biomedical subjects
A Morales
Publications and source records attributed to A Morales.
Correction of recurrent stress urinary incontinence by needle urethropexy with a vaginal wall sling.
OBJECTIVE: To review the results of a modification of the transvaginal needle urethropexy as a treatment for patients developing recurrence after surgical correction of stress urinary incontinence (SUI). SUBJECTS AND METHODS: Twelve women who had undergone previous surgery for SUI and had developed recurrence of the symptoms were treated by a needle urethropexy technique which employed an island of in situ vaginal skin as a sling to support the bladder neck and urethra. RESULTS: After a mean follow-up of 17.3 months, eight of the patients obtained excellent results, three experienced improvement and one was a failure. CONCLUSIONS: The vaginal wall sling needle urethropexy was a simple technique to perform and carries a low morbidity. The results are similar to those of the more elaborate traditional sling procedures reported in the literature.
Adult↗
Effect of chronic ethanol feeding on glutathione and functional integrity of mitochondria in periportal and perivenous rat hepatocytes.
Chronic ethanol feeding selectively impairs the translocation of cytosol GSH into the mitochondrial matrix. Since ethanol-induced liver cell injury is preferentially localized in the centrilobular area, we examined the hepatic acinar distribution of mitochondrial GSH transport in ethanol-fed rats. Enriched periportal (PP) and perivenous (PV) hepatocytes from pair- and ethanol-fed rats were prepared as well as mitochondria from these cells. The mitochondrial pool size of GSH was decreased in both PP and PV cells from ethanol-fed rats either as expressed per 10(6) cells or per microliter of mitochondrial matrix volume. The rate of reaccumulation of mitochondrial GSH and the linear relationship of mitochondrial to cytosol GSH from ethanol-fed mitochondria were lower for both PP and PV cells, effects observed more prominently in the PV cells. Mitochondrial functional integrity was lower in both PP and PV ethanol-fed rats, which was associated with decreased cellular ATP levels and mitochondrial membrane potential, effects which were greater in the PV cells. Mitochondrial GSH depletion by ethanol feeding preceded the onset of functional changes in mitochondria, suggesting that mitochondrial GSH is critical in maintaining a functionally competent organelle and that the greater depletion of mitochondrial GSH by ethanol feeding in PV cells could contribute to the pathogenesis of alcoholic liver disease.
Animals↗
[Molecular diagnosis of Duchenne/Becker muscular dystrophy in Venezuelan patients with the polymerase chain reaction].
Duchenne and Becker muscular dystrophy (DMD/BMD) are recessive X-linked neuromuscular diseases produced by allelic mutations in the human dystrophin gen. In the present study we determined the 14-deletion prone exons by multiplex PCR in 24 no related venezuelan patients with clinical diagnosis of DMD/BMD. We found 37% of intragenic deletions of which 77% were located at the "hot spot" deletion region that includes exons 44 to 55. The present study show that deletion frequency observed in venezuelan patients resembles some Asian populations and is lower than that observed in Europe and North America. The explanation of the low frequency detected in our patients is beyond the present study, but it is likely that different mutations, ocurring at other regions of the gene is determining a molecular heterogeneity of the DMD/BMD disease in Venezuela.
Chromosome Deletion↗
[Dietary ingestion of fluoride and caries prevalence in preschool and school children in cities with different fluoride content in the drinking water and diet].
The consumption of dietary fluoride and its relationship with dental caries prevalence was determined in 780 preschool children and 802 school children from quique, Arica, Santiago and San Antonio, where drinking water has different fluoride concentration. Dietary fluoride was determined from dietary records and fluoride content of foods. The fluoride consumption from drinking water was calculated by Galagan and Vermillion formula. The total fluoride consumption was obtained. The dental caries prevalence was established by the evaluation of dental caries index in deciduous (dmft) and permanent (DMFT) dentition. Significantly lower DMFT values were founded in cities with lower fluoride levels in drinking water. The exception was San Antonio, where high dietary fluoride explained the lower DMFT values relative to Santiago. Our results suggest that not only fluoride in water but also the consumption of fluoride rich foods has a significant impact on the prevalence of caries.
Adolescent↗
Comparison of peritonitis rates in children on CAPD with spike connector versus two disconnect systems.
The hospital records of all patients on continuous ambulatory peritoneal dialysis (CAPD) who were followed from January 1992 to June 1993 in a third level pediatric hospital were retrospectively reviewed to compare the peritonitis rates of groups of patients according to the dialysis system employed. All patients had Tenckhoff catheters installed by open technique. The groups were A) traditional spike connection system (37 patients), and B) disconnect systems (16 patients) that comprised the O-set system (10 patients) and the basic Y-set system (6 patients). Age was 11.9 +/- 3.7 years (mean +/- SD, range 3 months to 17 years). Follow-up time was 8.5 +/- 4.6 months for the traditional system group (304 cumulated months) and 7.2 +/- 3.6 months for the disconnect systems group (116 cumulated months). Peritonitis rates were 1 episode every 10 months for group A, versus 1 episode every 58 months for group B (p < 0.05). Our results strongly suggest that disconnect systems for peritoneal dialysis can significantly decrease peritonitis rates, although longer follow-up periods are needed.
Adolescent↗
Communication patterns in patients with erectile dysfunction and their partners.
Patients with erectile dysfunction (ED) and their partners (n = 18) were compared on perceived distress caused by the ED, attribution of responsibility for the ED and marital communication. Comparisons were also made between couples in whom the ED was organically based versus those in whom it was psychogenically based. No differences were found between organic versus psychogenic ED couples on perceived distress, attributions, or marital communication skills. Patients and partners differed on communication (P < 0.001), attributions (P < 0.001) and perceptions of distress experienced by their spouse (P < 0.001). However, both members of the couple found the ED equally distressing. Partners tended to attribute more responsibility for the ED to themselves when they believed it was psychogenic (P < 0.001), while patients claimed sole responsibility regardless of their perceptions of its etiology. Patients had clinically problematic communication scores (P < 0.001), while partners did not. Contrary to initial hypotheses, communication scores did not predict agreement/disagreement between patients and partners on perceived etiology, attributions or distress. Discussion is focused on the need for therapy to address couples' communication specific to sexual activity and the effects of the ED.
Communication↗
Nonsurgical management options in impotence.
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Autonomic Agents↗
Seasonal changes of the blood-testis barrier in viscacha (Lagostomus maximus maximus): a freeze-fracture and lanthanum tracer study.
Adult male viscachas (Lagostomus maximus maximus) were gathered from their natural habitat during the period of complete spermatogenesis (June) and during the month of maximum testicular regression (August). The testes were processed by conventional electron microscopic technique using lanthanum nitrate (electron-dense intercellular tracer) to define the intercellular spaces below the inter-Sertoli tight junctions and by freeze-fracture techniques. During complete spermatogenesis the tracer surrounds spermatogonia, preleptotene, and leptotene spermatocytes and stops at the level of the inter-Sertoli tight junctions below all germ cells displaying synaptonemal complexes (zygotene-pachytene spermatocytes) and germ cells in more advanced stages of differentiation. Conversely, during testicular regression the tracer percolates all intercellular spaces between Sertoli cells and the remaining germ cells (spermatogonia and few preleptotene and leptotene spermatocytes). During complete spermatogenesis, freeze-fracture replicas exhibit numerous inter-Sertoli tight junction strands parallel to each other and to the basal lamina. During spermatogenesis decay, the inter-Sertoli tight junctions are found to be short, tortuous, frequently interrupted, and often associated with extented membranous areas of gap junctions.
Animals↗
Silicone gel-filled testicular prosthesis and systemic disease.
Concerns exist regarding a possible link between the presence of silicone implants and the development of systemic disease. A retrospective review was carried out to determine whether or not a pattern of diseases could be found after the implantation of a testicular prosthesis. A specific pattern of diseases did not emerge in a group of 34 men harboring a scrotal silicone gel implant for a mean period of over five years. The findings, with a limited population and period of follow-up, are not conclusive but provide basis for reassurance to men about the health implications of their implants.
Adolescent↗
Dispersal of the sand fly Lutzomyia longipalpis (Diptera: Psychodidae) at an endemic focus of visceral leishmaniasis in Colombia.
Mark-release-recapture studies were carried out during 1990-1991 in El Callejón, Colombia, an endemic focus of American visceral leishmaniasis, to study the longevity, dispersal, and flight range of the principal vector, Lutzomyia longipalpis Lutz & Neiva. Several groups of wild-caught (n = 1,539) and laboratory-reared F1 (n = 2,208) sand flies were marked with fluorescent dusts and released. Recaptures at daytime resting sites, on animal bait, and in CDC light traps were made for 20 d following each release. From 2 to 9% of L. longipalpis were recaptured, a rate which differed between the sexes (7.7% male, 1.5% female). Overall, 49% of the L. longipalpis were recaptured between 0 and 50 m, 48% within 100 and 300 m, and nearly 3% at > or = 0.5 km from the release site. Sex differences in recapture site, distance flown, and direction were observed. Our results indicate that the dispersal behavior of peridomestic populations of L. longipalpis compares more closely with that of Old World sand fly species from similar habitats than to the sylvan Neotropical phlebotomines.
Animals↗
Novel preservation solution permits 24-hour preservation in rat and baboon cardiac transplant models.
BACKGROUND: Cardiac preservation for transplantation disrupts normal vascular homeostatic mechanisms. Hypoxia and reoxygenation increase endothelial cell permeability, induce procoagulant activity, and alter endothelial cell/leukocyte interactions, with a parallel reduction in endothelial cAMP and nitric oxide levels. Because hypoxia/reoxygenation simulates a significant component of the global ischemia/reperfusion of cardiac transplantation, we hypothesized that preservation failure may be related to these perturbations. This work focuses on repleting the intercellular/intracellular second messengers nitric oxide/cGMP and cAMP in the donor heart to enhance cardiac preservation for transplantation. METHODS AND RESULTS: A heterotopic rat heart transplant model was used to compare lactated Ringer's (LR) and University of Wisconsin (UW) solutions to a novel storage solution (Columbia University solution, CU), which contains a cAMP analogue (dibutyryl cAMP) and nitroglycerin (to enhance nitric oxide-related mechanisms). By 24 to 28 hours of preservation, no LR hearts survived (n = 9), 35% of UW hearts survived (n = 20), and 88% of CU-preserved hearts survived (n = 8; P < .05) versus LR or UW). The viability of preserved hearts was explored by determining whether CU preservation enabled myocytes to maintain resting membrane potentials and preserve their ability to generate an action potential in response to a field stimulus. Of 24 sites explored with a microelectrode in UW-preserved hearts, only 4% were able to generate an action potential, compared with 75% of 36 sites in CU-preserved hearts (P < .001), with corresponding preservation of resting membrane potential in the CU-preserved hearts (-13 mV for UW versus -54 mV for CU, P < .001). Orthotopic baboon cardiac transplantation performed after 24-hour simple hypothermic preservation demonstrated that no UW-preserved heart (n = 4) survived the perioperative period; in contrast, four of five hearts stored for 24 hours in CU solution sustained the recipient with minimal inotropic support, and two animals survived long-term. CONCLUSIONS: Sustaining higher levels of intercellular/intracellular second messengers cAMP and nitric oxide/cGMP provides a new approach to enhancing cardiac preservation.
Adenosine↗
Morphometric study of teeth in age calculation.
The diagnostic usefulness of some morphometric parameters of teeth in age determination were studied. In the first series 173 central incisors from 13-83 year-old individuals were examined and in the second series 72 teeth from 30 individuals (aged 39 to 80 years). Root transparency and dentinal tubule diameter were the most reliable parameters on the basis of image analysis (IBAS system) of scanning electron microscopic images. These variables were used in multiple linear regression analyses which led to the exclusion of secondary dentine as it did not improve the fit and therefore did not help to explain the dependent variable. The precise measurement of the morphometric variables we used facilitates age determination, reducing the mean error reported by other authors who used subjective estimates. Our results document the limited effectiveness of these parameters in age estimation due to individual variations caused by genetic factors and chewing habits.
Adult↗
Dynamics of step flow in a model of heteroepitaxy.
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Journal Article↗
Cholera: getting the message across.
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Cholera↗
Characterization of nuclear pore distribution in freeze-fracture replicas of seminiferous tubules isolated by transillumination.
Transilluminated seminiferous tubules were staged and utilized to determine the distribution of nuclear pore complexes in seminiferous tubules of the rat. Segments of seminiferous tubules of adult albino rats were separated and identified (in stages VII-VIII, IX-XI, XII-XIV, and V-VI), and then processed by freeze-fracture. Type A spermatogonia, the only spermatogonia located in seminiferous segments possessing stages IX-XI and XII-XIV, are oval cells in contact with the basal lamina. They either exhibit a random distribution of nuclear pores or a slight degree of clumping. Type B spermatogonia, found in segments possessing stages V-VI, exhibit, instead, a noticeable pore clustering. The identification of intermediate spermatogonia was not undertaken in this study. Preleptotene spermatocytes are easily identified in freeze-fracture by their location in segments with stages VII-VIII, by their arrangement in numerous groups between the basal lamina and the pachytene spermatocytes, and by their comparatively small size. They exhibit noticeable pore clustering. Leptotene (segments containing stages IX-XI) and zygotene (XII-XIV) spermatocytes show a more homogeneous distribution of nuclear pores. Pachytene spermatocytes are identified by their large size, by consistent detachment from the basal lamina and by being rather numerous and found in all the stages explored. Diplotene spermatocytes have the largest nuclei of all germ cells. They are always detached from the basal lamina and found only in seminiferous segments containing stage XIII. Pachytenes display a regular geometric array of pore aggregation with striking clustering, whereas diplotene nuclear pores takes on a random distribution. Secondary spermatocytes, only present in stage XIV intermingled with metaphase-anaphase profiles, are characterized in replicas by a paucity of evenly distributed nuclear pores.
Animals↗
Effect of diazepam on successive negative contrast in one-way avoidance learning.
The effect of administration of diazepam on successive negative contrast in one-way avoidance learning was examined in rats. Contrast was induced by shifting rats from a large reward, 30 s spent in the safe compartment, to a small reward, 1 s spent in the safe compartment. IP administration of 2 mg/kg diazepam eliminated this negative contrast. Moreover, this effect is dose dependent, with doses of 2 and 2.5 mg/kg, but not 0.5 mg/kg, effective in reliably reducing contrast. These results suggest the existence of similar or common underlying mechanisms in both aversive and appetitive contrast effects; they are discussed in light of the current theories of frustrative nonreward and as a mean of studying the behavioral and biological mechanisms of anxiety.
Animals↗
Desensitization of junctional and extrajunctional nicotinic ACh receptors expressed in Xenopus oocytes.
Desensitization of nicotinic acetylcholine receptors (AChRs) was studied using the Xenopus oocyte expression system. Mouse and cat extrajunctional AChRs expressed in oocytes desensitized more slowly than Torpedo AChRs. Substitution of the mouse gamma subunit into the Torpedo AChR reduced the rate of desensitization, making it similar to the mouse AChR. Likewise, substitution of the Torpedo gamma subunit into the mouse extrajunctional AChR increased the rate of desensitization, making it similar to the Torpedo AChR. Furthermore, mouse junctional AChRs in which the gamma subunit was replaced by the epsilon subunit desensitized more rapidly than either mouse or cat extrajunctional AChRs, and resembled Torpedo AChRs. Thus, in addition to other properties, junctional and extrajunctional AChRs differ with respect to desensitization, suggesting a possible role of desensitization in normal development of neuromuscular junction.
Animals↗