Reference values for neonates and children for the UF-100 urine flow cytometer.
Explore the source record for details and available documents.
Adolescent↗
Biomedical subjects
P Sinha
Publications and source records attributed to P Sinha.
A symmetry perceiving adaptive neural network and facial image recognition.
The paper deals with the forensic problem of comparing nearly from view and facial images for personal identification. The human recognition process for such problems, is primarily based on both holistic as well as feature-wise symmetry perception aided by subjective analysis for detecting ill-defined features. It has been attempted to approach the modelling of such a process by designing a robust symmetry perceiving adaptive neural network. The pair of images to be compared should be presented to the proposed neural network (NN) as source (input) and target images. The NN learns about the symmetry between the pair of images by analysing examples of associated feature pairs belonging to the source and the target images. In order to prepare a paired example of associated features for training purpose, when we select one particular feature on the source image as a unique pixel, we must associate it with the corresponding feature on the target image also. But, in practice, it is not always possible to fix the latter feature also as a unique pixel due to pictorial ambiguity. The robust or fault tolerant NN takes care of such a situation and allows fixing the associated target feature as a rectangular array of pixels, rather than fixing it as a unique pixel, which is pretty difficult to be done with certainty. From such a pair of sets of associated features, the NN searches out proper locations of the target features from the sets of ambiguous target features by a fuzzy analysis during its learning. If any of target features, searched out by the NN, lies outside the prespecified zone, the training of the NN is unsuccessful. This amounts to non-existence of symmetry between the pair of images and confirms non-identity. In case of a successful training, the NN gets adapted with appropriate symmetry relation between the pair of images and when the source image is input to the trained NN, it responds by outputting a processed source image which is superimposable over the target images and identity may subsequently be established by examining detailed matching in machine-made superimposed/composite images which are also suitable for presentation before the court. The performance of the proposed NN has been tested with various cases including simulated ones and it is hoped to serve as a working tool of forensic anthropologists.
Face↗
Increased expression of annexin I and thioredoxin detected by two-dimensional gel electrophoresis of drug resistant human stomach cancer cells.
The therapy of advanced cancer using chemotherapy alone or in combination with radiation or hyperthermia yields an overall response rate of about 20-50%. This success is often marred by the development of resistance to cytostatic drugs. Our aim was to study the global analysis of protein expression in the development of chemoresistance in vitro. We therefore used a cell culture model derived from the gastric carcinoma cell line EPG 85-257P. A classical multidrug-resistant subline EPG85-257RDB selected to daunorubicin and an atypical multidrug-resistant cell variant EPG85-257RNOV selected to mitoxantrone, were analysed using two-dimensional electrophoresis in immobilized pH-gradients (pH 4.0-8.0) in the first dimension and linear polyacrylamide gels (12%) in the second dimension. After staining with coomassie brilliant blue, image analysis was performed using the PDQuest system. Spots of interest were isolated using preparative two-dimensional electrophoresis and subjected to microsequencing. A total of 241 spots from the EPG85-257RDB-standard and 289 spots from the EPG85-257RNOV-standard could be matched to the EPG85-257P-standard. Microsequencing after enzymatic hydrolysis in gel, mass spectrometric data and sequencing of the peptides after their fractionation using microbore HPLC identified that two proteins annexin I and thioredoxin were overexpressed in chemoresistant cell lines. Annexin I was present in both the classical and the atypical multidrug-resistant cells. Thioredoxin was found to be overexpressed only in the atypical multidrug-resistant cell line.
Annexin A1↗
The MCM16 gene of the yeast Saccharomyces cerevisiae is required for chromosome segregation.
We have cloned and characterized the MCM16 gene required for the maintenance of minichromosomes in the yeast Saccharomyces cerevisiae. This gene corresponds to a 181-amino acid ORF, YPR046W, on chromosome XVI. Mutant cells carrying minichromosomes accumulate them in higher copy numbers than do wild-type cells. Intact dicentric plasmid could be recovered from the mutant, in contrast to the wild-type, in which the plasmid suffered frequent deletions. A wild-type centromere, CEN6, acts as a block to the transcription of a reporter gene, such as beta-galactosidase. This block was less effective in the mutant than in the wild-type strain, suggesting alterations in kinetochore assembly in the former. The mutant also showed increased sensitivity to the antimitotic drugs benomyl and thiabendazole. The mcm16 mutation caused a high rate of loss of chromosome III, without any significant increase in the recombination frequency. A strain carrying a deletion-disruption derivative of the MCM16 gene was viable and, when compared to the wild-type, did not show any significant changes in growth rate or cell morphology at 16, 23 and 37 degrees C. These properties show that MCM16 is required for an important but nonessential role that governs the kinetochore-microtubule mediated process of chromosome segregation.
Chromosome Deletion↗
Nitroglycerin to facilitate fetal extraction during cesarean delivery.
OBJECTIVE: To determine the efficacy of nitroglycerin in easing fetal extraction in elective cesarean deliveries in comparison with placebo and to collect maternal and fetal pharmacologic data after administration of nitroglycerin. METHODS: This randomized, double-blind clinical and descriptive pharmacokinetic study was carried out at the gynecology departments at Virchow Hospital and Charité Hospital (both university hospitals of Humboldt University, Berlin, Germany) between June 1994 and July 1996 in patients scheduled for elective cesarean delivery under general anesthesia. At the time of the uterine puncture incision, either 0.25 mg or 0.5 mg of nitroglycerin or a physiologic saline solution was administered as an intravenous bolus. Intraoperatively, maternal and neonatal pulse rates and blood pressure were monitored closely. The surgeons estimated reduction in uterine tone and the ease of fetal extraction by means of defined scales. Plasma concentrations of nitroglycerin and its metabolites were measured in maternal venous blood and from umbilical blood. RESULTS: Ninety-seven patients were included in the statistical evaluation of the study; 32 received 0.25 mg of nitroglycerin, 34 received 0.5 mg of nitroglycerin, and 31 received placebo. The evaluation of the surgeons' estimation revealed no significant difference in ease of fetal extraction (statistical power 0.7) and no significant reduction in uterine tone under treatment with both nitroglycerin dosages in comparison with placebo. Only substance-specific maternal side effects were noted. The neonates' conditions were not affected by administration of nitroglycerin. The median fetal-maternal ratio of venous nitroglycerin plasma levels was approximately 1:400 in the 0.25-mg nitroglycerin group and 1:160 in the 0.5-mg nitroglycerin group. Approximately 11-12 times more nitroglycerin was detected in the venous umbilical branch than in the arterial branch. CONCLUSION: Administration of nitroglycerin leads to no clinically relevant easing of fetal extraction, at least not in elective cesarean deliveries after the 34th week of gestation. With regard to pharmacokinetics, the measured median fetal-maternal venous nitroglycerin concentration was 1:400 in the 0.25-mg group and 1:160 in the 0.5-mg group.
Adult↗
Spaceflight influences on ocular counterrolling and other neurovestibular reactions.
Exposure to extended periods of weightlessness in orbital flight has profound effects on the neurovestibular system and influences head and eye movements, postural control, and spatial orientation. The associated space motion sickness is among the earliest of the signs of adaptation to this new environment. This report both reviews the prominent neurovestibular phenomena associated with going into space and returning to earth and relates the issues to vestibular compensation and rehabilitation. New results from the Spacelab SLS-2 mission are included, showing significant reductions in postflight ocular counterrolling and changes in ocular counterrolling left/right asymmetries after 2 weeks in space.
Humans↗
Top-down influences on stereoscopic depth-perception.
The interaction between depth perception and object recognition has important implications for the nature of mental object representations and models of hierarchical organization of visual processing. It is often believed that the computation of depth influences subsequent high-level object recognition processes, and that depth processing is an early vision task that is largely immune to 'top-down' object-specific influences, such as object recognition. Here we present experimental evidence that challenges both these assumptions in the specific context of stereoscopic depth-perception. We have found that observers' recognition of familiar dynamic three-dimensional (3D) objects is unaffected even when the objects' depth structure is scrambled, as long as their two-dimensional (2D) projections are unchanged. Furthermore, the observers seem perceptually unaware of the depth anomalies introduced by scrambling. We attribute the latter result to a top-down recognition-based influence whereby expectations about a familiar object's 3D structure override the true stereoscopic information.
Brain↗
Contribution of early acute rejection episodes to chronic rejection in a rat kidney retransplantation model.
Chronic graft rejection represents the single most important risk factor for unsatisfactory long-term results after organ transplantation. In addition to various alloantigen dependent and independent factors, acute rejection episodes have been cited as a major immunological risk factor. However, the effects of acute rejection episodes on long-term graft outcome remains unknown. To examine the influence of a single early rejection event on ultimate graft outcome, acutely rejecting rat kidney grafts were retransplanted sequentially into syngeneic rats and their functional and structural behavior assessed over time. LEWxBNF1 kidney allografts and LEW isografts were removed from their LEW recipients after three, four, five and seven days (N = 12/group/time period) and retransplanted into donor strain hosts. The grafts were followed functionally and harvested four, eight, and 32 weeks later. Urinary protein excretion was measured weekly. Kidneys were examined morphologically and immunohistologically using monoclonal antibodies (mAbs) against macrophages (ED-1), T cells and their subsets (CD5, CD4, CD8), MHC class II expression (OX3) and adhesion molecules (ICAM-1 and LFA-1alpha). The mean standard time +/- SD of non-retransplanted allografts was 14.5 +/- two days; isografts functioned indefinitely. At five and seven days, acutely rejecting allografts showed massive cellular infiltrates associated with extensive necrosis. These changes could not be reversed by retransplantation and the syngeneic recipients later died of renal failure. In contrast, most allografts retransplanted earlier in the process recovered completely when retransplanted after three (12 of 12 allografts) and four (7 of 12 allografts) days. During the subsequent follow-up period, urinary protein excretion was comparable in retransplanted allografts and isografts. The increased mononuclear cell infiltration in non-retransplanted allografts seen at three and four days was only occasionally observed during the follow-up period after retransplantation. Only a few sclerosed glomeruli (approximately 15%), mild arterial changes and minimal cellular infiltrates were observed by 32 weeks, which were similar to that seen in retransplanted isografts. A single acute rejection episode was completely reversible and did not progress to chronic rejection if retransplanted into syngeneic donors when the inflammatory changes are still early. Those results demonstrate the critical effect of alloantigen-dependent events on chronic graft deterioration, and indicate that prompt and aggressive treatment of initial acute rejection episodes are beneficial to protect against late deleterious changes in the graft.
Animals↗
Evaluation of Internet-based oncologic teaching for medical students.
BACKGROUND: Electronic tools with substantial educational applications are now widely available. METHODS: In a prospective, randomized study, the value of Web-based educational tools for teaching second-year medical students was evaluated. The 35-hour, image-intensive multifaculty neoplasia course was selected for the experiment, with 103 students assigned to the control group (C) and 61 to the experimental group (E). Representative password-controlled multimedia course modules, accessible via the Internet, were developed. The E cohort was exposed to both classroom and Web-aided materials, whereas the C group had access to the Web modules only after the experiment was concluded (but before the final examination). Pre- and post-exposure questionnaires assessed computer knowledge, familiarity with the Internet, availability of computer access, and the value of Web-based education for both cohorts. Additionally, pre-and post-exposure tests were administered to both cohorts based on educational materials presented in the Web modules. RESULTS: The overall participation rate was 64% (E = 69%; C = 60%). The post-test showed no major performance difference between the two groups. The questionnaires revealed that: less than 1% of the students had not accessed the Internet previously; less than 5% had not used the Internet for medical education before; 34% felt that computer resources on campus were inadequate; and over 75% found Web-based education to be an important additional educational resource. The major negative aspect was the slow pace of data transfer for modem-based home access. Only 1% of students felt that Web-based education could completely replace traditional teaching. CONCLUSION: The potential for incorporating Web-based education in the medical curriculum is considerable.
Computer Literacy↗
Late clotted haemothorax after blunt chest trauma.
A clotted haemothorax can develop any time after blunt chest trauma. Two cases are described in which late clotted haemothoraces developed which were treated by limited thoracotomy and evacuation of clots. Late clotted haemothorax may occur even in the absence of any abnormal initial clinical findings. Early detection and treatment is important to avoid the complications of fibrothorax and empyema with permanent pulmonary dysfunction. After blunt chest trauma patients should be advised to return to the accident and emergency department for assessment on development of any new chest symptom. Under these circumstances a chest x ray is mandatory to exclude a haemothorax.
Accidental Falls↗
Preanalytical determinants of total and free prostate-specific antigen and their ratio: blood collection and storage conditions.
Explore the source record for details and available documents.
Blood Preservation↗
Top-down learning of low-level vision tasks.
Perceptual tasks such as edge detection, image segmentation, lightness computation and estimation of three-dimensional structure are considered to be low-level or mid-level vision problems and are traditionally approached in a bottom-up, generic and hard-wired way. An alternative to this would be to take a top-down, object-class-specific and example-based approach. In this paper, we present a simple computational model implementing the latter approach. The results generated by our model when tested on edge-detection and view-prediction tasks for three-dimensional objects are consistent with human perceptual expectations. The model's performance is highly tolerant to the problems of sensor noise and incomplete input image information. Results obtained with conventional bottom-up strategies show much less immunity to these problems. We interpret the encouraging performance of our computational model as evidence in support of the hypothesis that the human visual system may learn to perform supposedly low-level perceptual tasks in a top-down fashion.
Algorithms↗
Reciprocal interactions between occlusion and motion computations.
The "aperture problem" refers to the inherent ambiguity of the motion generated by an untextured contour moving within an aperture. The limited spatial extent of the receptive fields of neurons in cortical areas like V1 and MT render them susceptible to this problem. Most psychophysical experiments have probed how the visual system overcomes the aperture problem by presenting moving contours behind one or more simulated apertures. The assumption has been that the computational ambiguities that arise in resolving these displays are equivalent to the computational problems created by receptive fields that sample a small region of visual space. Evidence is presented here that challenges this view. We demonstrate that a fundamental computational difference in the interpretation of contour terminators arises in these two variants of the aperture problem. When the aperture is a receptive field, and a moving contour extends beyond its boundaries, the contour "terminators" delimit the boundaries of the receptive field, not the ends of the contour. In contrast, when a moving contour is viewed through a simulated aperture, the contour terminators are generated by the occluding edges of the aperture. In a series of experiments, we show that reciprocal interactions arise between computations of occlusion and those of motion direction and integration. Our results demonstrate that the visual system solves the aperture problem by decomposing moving contours into moving segments, and unpaired terminators that arise from the accretion and deletion of contours behind occluding edges, generating both coherent motion and illusory occluding surfaces.
Motion Perception↗
The mcm17 mutation of yeast shows a size-dependent segregational defect of a mini-chromosome.
Mini-chromosome-maintenance (mcm) mutants were described earlier as yeast mutants which could not stably maintain mini-chromosomes. Out of these, the ARS-specific class has been more extensively studied and is found to lose chromosomes and mini-chromosomes due to a defect in the initiation of DNA replication at yeast ARSs. In the present study we have identified a number of mcm mutants which show size-dependent loss of mini-chromosomes. When the size of the mini-chromosome was increased, from about 15 kb to about 60 kb, there was a dramatic increase in its mitotic stability in these mutants, but not in the ARS-specific class of mutants. One mutant, mcm17, belonging to the size-dependent class was further characterized. In this mutant, cells carried mini-chromosomes in significantly elevated copy numbers, suggesting a defect in segregation. This defect was largely suppressed in the 60-kb mini-chromosome. A non-centromeric plasmid, the TRP1ARS1 circle, was not affected in its maintenance. This mutant also displayed enhanced chromosome-III loss during mitosis over the wild-type strain, without elevating mitotic recombination. Cloning and sequencing of MCM17 has shown it to be the same as CHL4, a gene required for chromosome stability. This gene is non-essential for growth, as its disruption or deletion from the chromosome did not affect the growth-rate of cells at 23 degrees C or 37 degrees C. This work suggests that centromere-directed segregation of a chromosome in yeast is strongly influenced by its length.
Cell Cycle Proteins↗
Incidental appendectomy during gynecological surgery.
Explore the source record for details and available documents.
Adult↗
Unusual genome organisation in Entamoeba histolytica leads to two overlapping transcripts.
We have isolated homologs of the mini chromosome maintenance (MCM) gene family from the parasitic protozoan Entamoeba histolytica. The full length genomic and cDNA clones for the Eh MCM3 gene have been characterised. The Eh MCM3 gene is much smaller than the Saccharomyces cerevisiae MCM3 gene and other eukaryotic homologs of the MCM3/P1 family. The predicted Eh Mcm3 protein was 597 amino acids long and showed 37 and 46% positional identity with the Sc Mcm3 and the mouse P1 homologs respectively. While proceeding along the chromosome from the Eh MCM3 gene, we have identified a homolog (Eh PAK) of the murine p21 activated kinase (Rn KPAK), or S. cerevisiae STE20. Eh PAK lies 126 bp upstream of the Eh MCM3 gene. The predicted Eh p21 activated kinase protein was 459 amino-acids long and showed 33% positional identity with the murine p21 activated kinase and its yeast homolog Ste20. Analysis of cDNA and genomic sequences shows that the 3' untranslated region (UTR) of the Eh PAK mRNA and the 5' UTR of the Eh MCM3 mRNA are transcribed from a common 40 bp genomic segment. This is the first report of an amoeba gene being physically linked to a second gene such that their transcripts are overlapping and there is no non-transcribed intergenic region between the two genes. Primer extension studies have confirmed that unlike most E. histolytica genes, which have short 5' UTRs, the Eh MCM3 mRNA has a 126 bp long 5' UTR and the Eh PAK mRNA has a 265 bp long 5' UTR.
Amino Acid Sequence↗
Evaluation of frictional resistance in esthetic brackets.
The purpose of this study was to measure the frictional forces generated between composite, ceramic, and metal brackets and selected wire alloy-size combinations with elastomeric and stainless steel ligatures in a dry environment. Four types of composite, one ceramic, one sapphire, and one metal bracket were tested with stainless steel, nickel-titanium, and beta-titanium wires. The testing was performed with two wire sizes in the 0.018-inch slot brackets and three wire sizes in the 0.022-inch slot bracket. The recently introduced composite brackets were found to offer lower frictional resistance than the ceramic and stainless steel brackets, regardless of the wire size, wire alloy, and type of ligation. The wire alloy with the least friction was stainless steel, followed by beta-titanium and nickel-titanium. Mean variability in friction, as reflected by the magnitude of the standard deviations, was 2.7 to 3 times more with the stainless steel ligation than the elastomeric ligation.
Bicuspid↗
Addison's disease in pregnancy presenting as hyperemesis gravidarum.
Explore the source record for details and available documents.
Journal Article↗