HIV infection amongst leprosy patients in south India

We use the trapezoidal lamellar incision as standard construction for sutureless self-sealing wound closure in our clinic: a 7 mm incision for phacoemulsification and implantation of a 6.5 mm optic diameter PMMA posterior chamber less (PCL) and an incision up to 11 mm for ECCE with standard PCL. The operation can be performed in a nearly closed system because of the self-sealing wound construction. Experiments in cadaver eyes showed that the wound closure of a 7 mm incision with the no-stitch technique ruptured at a pressure five times greater than the cross-stitch-sutured corneoscleral incision and in an 11 mm incision four times greater (602 +/- 149 mmHg and 150 +/- 29 mmHg). Due to the high stability of the wound closure, no sutures are necessary. Complications arising in connection with sutures are therefore avoided. Clinically, two typical postoperative complications were observed: hypotony occurred in 1% and anterior chamber hemorrhage in 5%. These complications are exclusively caused by imperfection of the internal corneal opening.     

A computational approach to analyzing sentential speech perception: phoneme-to-phoneme stimulus-response alignment

A solution to the following problem is presented: Obtain a principled approach to studying error patterns in sentence-length responses obtained from subjects who were instructed to simply report what a talker had said. The solution is a sequence comparator that performs phoneme-to-phoneme alignment on transcribed stimulus and response sentences. Data for developing and testing the sequence comparator were obtained from 139 normal-hearing subjects who lipread (speechread) 100 sentences and from 15 different subjects who identified nonsense syllables by lipreading. Development of the sequence comparator involved testing two different costs metrics (visemes versus Euclidean distances) and two related comparison algorithms. After alignments with face validity were achieved, a validation experiment was conducted for which measures from random versus true stimulus-response sentence pairs were compared. Measures of phonemes correct and substitution uncertainty were found to be sensitive to the nature of the sentence pairs. In particular, correct phoneme matches were extremely rare in random pairings in comparison with true pairs. Also, an information-theoretic measure of uncertainty for substitutions in true versus random pairings showed that uncertainty was always higher for random than for true pairs.     

Involvement of calcium and L-type channels in nicotine-induced antinociception

The nature of the signaling process activated by neuronal nicotinic receptors has not been fully defined; however, several recent studies have implicated the involvement of calcium ion fluxes in the response to nicotine on a cellular level. Alteration of nicotine-induced antinociception in mice after systemic administration was therefore investigated in the presence of several drugs that increase intracellular calcium. Calcium, (+/-)-BAYK 8644, thapsigargin, glyburide and A23187 administered intrathecally (i.t.) were found to enhance nicotine-induced antinociception by shifting its dose-response curve to the left. Conversely, i.t. administration of agents which decrease intracellular calcium, such as EGTA and alpha-calcitonin gene-related peptide, blocked nicotine-induced antinociception. These findings support a role for spinal intracellular calcium in the pharmacological effects of nicotine. Additionally, blockade of antinociception by nimodipine and nifedipine indicates that a L-type calcium channel is involved in nicotine's effect. However, nicotine did not compete for [3H] nitrendipine binding. Intrathecal administration of mecamylamine, a nicotinic antagonist, resulted in a blockade of antinociception produced by the i.t. injection of thapsigargin, A23187, calcium and (+/-)-BAYK 8644. The mechanism of mecamylamine's antagonism of nicotine is uncertain. However, these results suggest that mecamylamine blocks the effects of drugs which increase intracellular calcium by either a modulation of intracellular calcium-dependent mechanisms or a blockade of calcium channels. Thus, mecamylamine could modulate a calcium signaling process secondary to receptor activation resulting in blockade of antinociception produced by diverse agents.     

Visual input and lateralization of brain function in learning in the chick

Several lines of evidence (biochemical, neuroanatomical, electrophysiological, and behavioural) have indicated a critical role for the intermediate medial hyperstriatum ventrale of the chick forebrain in the acquisition of a passive avoidance response. Previous lesion studies indicated that bilateral or left, but not right, pretraining intermediate medial hyperstriatum ventrale lesions interfere with the acquisition of this task. We have further analysed this asymmetrical involvement of the intermediate medial hyperstriatum ventrale by use of a monocular learning protocol and intermediate medial hyperstriatum ventrale lesions (sham, bilateral, or unilateral). The results indicated that there is interocular transfer of information of passive avoidance learning between the two eye systems, with a tendency to be more successful from the right eye system to the left than in the opposite direction. As in binocular conditions, bilateral pretraining intermediate medial hyperstriatum ventrale lesions impair learning in monocularly trained animals. Unilateral lesions to either left or right monocularly trained experimental animals resulted in amnesia when they were made to the right intermediate medial hyperstriatum ventrale and the chicks were trained/tested with the left eye open. These results indicate that, although right intermediate medial hyperstriatum ventrale lesions do not result in amnesia in binocular animals, this region is capable of participating in memory acquisition processes. They also suggest a connection between lateralization of intermediate medial hyperstriatum ventrale function in passive avoidance learning and the behavioural and structural visual asymmetries known to occur in chicks.     

Evaluation of bone turnover in type I osteoporosis using biochemical markers specific for both bone formation and bone resorption

Multivariate analysis was used to determine which characteristics: sex of the proband, sibling sex, severity of the proband's defect or family history, are the best predictors of recurrence risk among siblings of individuals with non-syndromic cleft lip with or without cleft palate (CL +/- P). Sibling recurrence risks are not significantly related to the sex of the proband. Severity of the proband's defect, classified by the extent of the lip defect (unilateral versus bilateral), was found to be a significant predictor of sibling recurrence, whereas involvement of the palate in the proband's defect was not. A positive family history of clefting (i.e. at least one affected first-degree relative in addition to the proband) and the sex of the sibling were also found to be significant predictors of sibling recurrence. The associations between sibling risk and family history, and sibling risk and bilaterality of the proband's defect appear to be mildly confounded. After adjusting for the effects of family history, the risk to siblings of probands with bilateral lip defects is twice the risk to siblings of probands with unilateral defects (O.R. = 2.00; 95% C.I. 1.25-3.19). A positive family history of clefting increases the risk to siblings by greater than 4-fold (O.R. = 4.49; 95% C.I. 2.74-7.35), after adjusting for the extent of the proband's lip defect. These results provide a rational strategy for identifying subsets of the 'at risk' population which have markedly different recurrence risks. This information is important for genetic counseling, since it allows for more precise estimation of sibling recurrence risks in individual cases.(ABSTRACT TRUNCATED AT 250 WORDS)     

Vectorial release of poliovirus from polarized human intestinal epithelial cells

Polarized epithelial cells represent the primary barrier to virus infection of the host, which must also be traversed prior to virus dissemination from the infected organism. Although there is considerable information available concerning the release of enveloped viruses from such cells, relatively little is known about the processes involved in the dissemination of nonenveloped viruses. We have used two polarized epithelial cell lines, Vero C1008 (African green monkey kidney epithelial cells) and Caco-2 (human intestinal epithelial cells), infected with poliovirus and investigated the process of virus release. Release of poliovirus was observed to occur almost exclusively from the apical cell surface in Caco-2 cells, whereas infected Vero C1008 cells exhibited nondirectional release. Structures consistent with the vectorial transport of virus contained within vesicles or viral aggregates were observed by electron microscopy. Treatment with monensin or ammonium chloride partially inhibited virus release from Caco-2 cells. No significant cell lysis was observed at the times postinfection when extracellular virus was initially detected, and transepithelial resistance and vital dye uptake measurements showed only a moderate decrease. Brefeldin A was found to significantly and specifically inhibit poliovirus biosynthetic processes by an as yet uncharacterized mechanism. The vectorial release of poliovirus from the apical (or luminal) surface of human intestinal epithelial cells has significant implications for viral pathogenesis in the human gut.