Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “virtual screening”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,441 records · Page 80Linked to original sources
PubMed1986

Office diagnosis of asymptomatic bacteriuria in pregnant women.

Diagnosis and treatment of asymptomatic bacteriuria in pregnant patients can virtually eliminate pyelonephritis, the most common medical cause for antepartum hospitalization. However, the ever-increasing cost of the urine culture has led most clinicians away from routine urine screening. Uricult dip-slide paddles provide an inexpensive, efficient way to screen urine. Clean-catch urine specimens were obtained from 544 consecutive asymptomatic pregnant patients seen in the outpatient obstetric clinic at the Medical University of South Carolina. Specimens were analyzed by both traditional culture techniques and the Uricult dip-slide paddles. By comparison, the Uricult test detected 55 of the 56 significant gram-negative urinary pathogens found by culture. Detection of potential gram-positive pathogens is more difficult. A scheme is proposed that allows reliable, inexpensive surveillance in all pregnant patients. Hopefully, this algorithm will rekindle the obstetrician's interest in urine screening.

Ambulatory Care↗
PubMed1978

Experience with the radioimmunoassay for parathyroid hormone in the diagnosis of primary hyperparathyroidism.

Our results with radioimmunoassay studies for parathyroid hormone performed during the last 6 years are compared retrospectively to results of the laboratory tests customarily secured when hyperparathyroidism is suspected. The results obtained in patients with known primary hyperparathyroidism and in patients with unconfirmed but presumptive hyperparathyroidism are compared to the results obtained from a group of normal controls. Despite the fact that certain discrepant results were noted in the earlier assay techniques the over-all results and, in particular, those of more recent years have been highly sensitive and reproducible corroboratives of the existence of primary hyperparathyroidism. About two-thirds of the patients with primary hyperparathyroidism will present to the urologist. All patients with calcium-containing stones should have at least 3 determinations of the serum calcium in screening for primary hyperparathyroidism. The radioimmunoassay for parathyroid hormone provides the most reliable confirmation. The patient with calculous disease, elevation of the immunoreactive parathyroid hormone level and hypercalcemia is virtually certain to have primary hyperparathyroidism.

Animals↗
PubMed2000

Mucosal production of antigastric autoantibodies in Helicobacter pylori gastritis.

BACKGROUND: Apart form bacterial virulence factors of Helicobacter pylori, certain host factors influence the pathogenesis of H. pylori gastritis. In particular, antigastric autoantibodies that are detectable in the sera of a substantial proportion of H. pylori were shown to correlate with the development of gastric atrophy. The aim of this study was to analyze the possible antigastric autoimmune response in H. pylori gastritis at the site where the action is, i.e. , in the gastric mucosa. MATERIAL AND METHODS: Gastric biopsy specimens from antrum and corpus mucosa of 24 H. pylori-infected and of 33 noninfected patients were cultured for 3 days, and tissue culture supernatants were analyzed for the amount of locally produced IgA and IgG. Antigastric autoantibodies were screened in the sera and in the supernatants by means of immunohistochemistry. RESULTS: The infected patients had significantly higher concentrations of locally produced IgA, whereas the IgG concentrations were virtually the same in infected and noninfected patients. IgG or IgA antigastric autoantibodies, or both, were detectable only in the sera (38%) and supernatants (17%) of infected patients. Interestingly, the patient with the strongest local autoimmune response showed body-predominant H. pylori gastritis, with destruction of gastric glands and atrophy of the body mucosa. CONCLUSIONS: These results demonstrate that antigastric autoimmune reactions are detectable at the site of the disease and might be relevant for the pathogenesis of gastric mucosa atrophy in H. pylori gastritis.

Adult↗
PubMed2003

Pediatric oligodendrogliomas: a study of molecular alterations on 1p and 19q using fluorescence in situ hybridization.

Oligodendrogliomas (OGs) are rare in children and have not been well characterized from a molecular viewpoint. In adults, losses on chromosomes 1p and/or 19q are common in "oligodendroglial" neoplasms and are highly associated with chemosensitivity and greater length of survival, especially in the anaplastic category. We have analyzed the 1p/19q status of pediatric OGs and compared it with similar alterations in adult OGs. Paraffin sections from 26 pediatric OGs (21 WHO Grade II OGs: 2 anaplastic oligodendrogliomas [AOGs]: and 3 mixed oligo-astrocytomas [MOA]) were retrieved. Fluorescence in situ hybridization (FISH) was performed using probes spanning the 1p32 and 19q13 regions. In tumors from children 0 to 9 years of age (n = 15), none had any deletions on 1p or 19q, but 2 had polysomies for 1p and/or 19q. All are alive and 4 have had recurrences. In tumors from children > 9 years, losses were identified on chromosomes 1p (5/11; 45%) and/or 19q (3/11; 27%), but to a much lesser extent than that observed in adult OGs. Tumors from 6 older patients also had polysomies for 1p and/or 19q. Although the majority of the older children are alive, 4 had recurrences. Curiously, 2 of the older children with AOGs had combined losses and polysomies on 1p and 19q, but responded poorly to treatment and died within a year. We conclude that alterations on 1p or 19q are infrequent in pediatric compared to adult OGs and are virtually absent in OGs presenting in the first decade of life. Compared to adults therefore, different genetic pathways are likely involved in the pathogenesis of most pediatric OGs. Genomic screening on a larger series is clearly indicated to delineate the unique molecular characteristics of these rare pediatric tumors.

Adolescent↗
PubMed2006

Metal slits and liquid crystals at microwave frequencies.

While the use of liquid crystals (LCs) over the visible region is ubiquitous in flat-screen displays, there has been little by the way of applications at other wavelengths. Specifically, notwithstanding the continuing permittivity anisotropy to be found at longer wavelengths, there has been virtually no development in the microwave domain. This is largely due to the fact that scaling up the micrometer-thick LC layers used for visible radiation to millimetre dimensions is seen as impractical. In this study, it is shown how, using thin slits in metal structures, a completely new generation of LC devices for use at microwaves may be realized. Such structures include slatted metal Fabry-Perot resonators, beam-steering devices, thin flexible voltage tunable filters and even cascade structures with strongly enhanced and reshaped microwave fields.

Journal Article↗
PubMed2000

Predominance of a 6 bp deletion in exon 2 of the LDL receptor gene in Africans with familial hypercholesterolaemia.

In South Africa, the high prevalence of familial hypercholesterolaemia (FH) among Afrikaners, Jews, and Indians as a result of founder genes is in striking contrast to its reported virtual absence in the black population in general. In this study, the molecular basis of primary hypercholesterolaemia was studied in 16 Africans diagnosed with FH. DNA analysis using three screening methods resulted in the identification of seven different mutations in the coding region of the low density lipoprotein (LDLR) gene in 10 of the patients analysed. These included a 6 bp deletion (GCGATG) accounting for 28% of defective alleles, and six point mutations (D151H, R232W, R385Q, E387K, P678L, and R793Q) detected in single families. The Sotho patient with missense mutation R232W was also heterozygous for a de novo splicing defect 313+1G-->A. Several silent mutations/polymorphisms were detected in the LDLR and apolipoprotein B genes, including a base change (g-->t) at nucleotide position -175 in the FP2 LDLR regulatory element. This promoter variant was detected at a significantly higher (p<0.05) frequency in FH patients compared to controls and occurred in cis with mutation E387K in one family. Analysis of four intragenic LDLR gene polymorphisms showed that the same chromosomal background was identified at this locus in the four FH patients with the 6 bp deletion. Detection of the 6 bp deletion in Xhosa, Pedi, and Tswana FH patients suggests that it is an ancient mutation predating tribal separation approximately 3000 years ago.

Adolescent↗
PubMed2003

Molecular diagnosis of multiple endocrine neoplasia Type 2.

Multiple endocrine neoplasia Type 2 is a rare familial cancer syndrome transmitted in an autosomal dominant manner. It is characterized by the association of medullary thyroid carcinoma with pheochromocytoma and hyperparathyroidism. Medullary thyroid carcinoma, present in virtually all patients, is the principal cause of death. In 1993, germline mutations in the RET proto-oncogene were identified as the underlying cause of the syndrome. Genetic screening of at-risk family members can now be performed with high specificity and sensitivity. The ability to determine gene carrier status at a preclinical stage is of great value as it allows early prophylactic thyroidectomy. The specific RET codon mutation correlates with clinical variants of the syndrome, age at onset and aggressiveness of medullary thyroid carcinoma. This review will focus on mutational spectrum, genotype-phenotype correlations and clinical decisions based on genetic information.

Genetic Testing↗
PubMed1977

Experience with the radioimmunoassay for parathyroid hormone in the diagnosis of primary hyperparathyroidism.

Our results with radioimmunoassay studies for parathyroid hormone performed during the last 6 years are compared retrospectively to results of the laboratory tests customarily secured when hyperparathyroidism is suspected. The results obtained in patients with known primary hyperparathyroidism and in patients with unconfirmed but presumptive hyperparathyroidism are compared to the results obtained from a group of normal controls. Despite the fact that certain discrepant results were noted in the earlier assay techniques the over-all results and, in particular, those of more recent years have been highly sensitive and reproducible corroboratives of the existence of primary hyperparathyroidism. About two-thirds of the patients with primary hyperparathyroidism will present to the urologist. All patients with calcium-containing stones should have at least 3 determinations of the serum calcium in screening for primary hyperparathyroidism. The radioimmunoassay for parathyroid hormone provides the most reliable confirmation. The patient with calculous disease, elevation of the immunoreactive parathyroid hormone level and hypercalcemia is virtually certain to have primary hyperparathyroidism.

Calcium↗
PubMed2005

The applicability of holography in forensic identification: a fusion of the traditional optical technique and digital technique.

In this study, the applicability of holography in the 3-dimensional recording of forensic objects such as skulls and mandibulae, and the accuracy of the reconstructed 3-D images, were examined. The virtual holographic image, which records the 3-dimensional data of the original object, is visually observed on the other side of the holographic plate, and reproduces the 3-dimensional shape of the object well. Another type of holographic image, the real image, is focused on a frosted glass screen, and cross-sectional images of the object can be observed. When measuring the distances between anatomical reference points using an image-processing software, the average deviations in the holographic images as compared to the actual objects were less than 0.1 mm. Therefore, holography could be useful as a 3-dimensional recording method of forensic objects. Two superimposition systems using holographic images were examined. In the 2D-3D system, the transparent virtual holographic image of an object is directly superimposed onto the digitized photograph of the same object on the LCD monitor. On the other hand, in the video system, the holographic image captured by the CCD camera is superimposed onto the digitized photographic image using a personal computer. We found that the discrepancy between the outlines of the superimposed holographic and photographic dental images using the video system was smaller than that using the 2D-3D system. Holography seemed to perform comparably to the computer graphic system; however, a fusion with the digital technique would expand the utility of holography in superimposition.

Adult↗
PubMed2026

Assessing perinatal depression identifying abilities among maternal and child health workers in rural China using smartphone-based virtual patients: a multi-center cross-sectional study.

OBJECTIVE: To assess rural maternal and child health (MCH) workers' virtual patients (VPs)-assessed performance in identifying perinatal depression (PND) using smartphone-based VPs, and to identify factors associated with this performance in rural Hunan, China. METHODS: A multicentre cross-sectional study was conducted in Hunan Province, China. A standardized questionnaire collected demographic and work-related characteristics of rural MCH workers. Smartphone-based VPs were used to assess PND identification performance in a simulated clinical scenario. An overall score &#x2265;60 was used as a prespecified operational benchmark across consultation, ancillary assessment, diagnosis, management, and health education domains. Data were analyzed using SPSS 26.0. RESULTS: A total of 375 rural MCH workers participated, yielding an effective response rate of 90.4%. Only 25.9% met the prespecified operational benchmark for VP-assessed PND identification performance. The mean accuracy scores for consultation, ancillary assessment, diagnosis, management, and health education were 94%, 48%, 64%, 58%, and 74%, respectively. Complete consultation accuracy was higher among MCH workers from township health centers than among those from county-level MCH hospitals. MCH workers aged 18-39 years showed higher odds of complete diagnostic accuracy for PND than those aged &#x2265;40 years. CONCLUSIONS: Smartphone-based VP assessment was feasible in rural MCH settings and revealed suboptimal PND identification performance. Mobile VPs may help identify frontline performance gaps and inform targeted training, but further validation against real-world clinical performance, or standardized patient encounters is needed before large-scale implementation. These findings may support targeted capacity-building for rural MCH workers and more equitable perinatal mental health care.

Humans↗
PubMed1996

Screening for psychosocial problems in 4-5-year-olds during routine EPSDT examinations: validity and reliability in a Mexican-American sample.

The effectiveness of the Pediatric Symptom Checklist (PSC) as a psychosocial screening measure to meet Federal Medicaid/Early and Periodic Screening, Diagnosis, and Treatment (EPSDT) requirements was examined in 117 low-income preschool (aged 4-5 years old) Hispanic children during well-child examinations in three clinics over an 8-month period. The PSC identified 7% of the sample as at risk for psychosocial problems. The PSC was significantly associated with parental ratings of the children's problems in functioning, with pediatric clinicians' decisions to make mental health referrals, with degrees of associations similar to those found between PSC scores, and with the same measures with school-aged children in the same clinics. Cronbach's alpha was high (r = .87) and virtually identical in English, Spanish, oral, and written formats. Although it identified a slightly lower rate of psychosocial problems in 4-5-year-olds than it had in school-aged children, the PSC appeared to provide an effective method of screening for psychosocial problems during EPSDT examinations.

California↗
PubMed1997

Evaluation of the CytoRich slide preparation process.

OBJECTIVE: To compare the quality and sensitivity of CytoRich slides with conventional cytologic smears and to evaluate the benefits of using this technology as an add-on procedure. STUDY DESIGN: The study design consisted of non-randomized, paired cervical samples. The subjects were 2,125 Sydney women who were routine patients of 13 gynecologists and 8 general practitioners and had cytologic smears taken between January and June 1995. All smears were taken using the Cervex brush. After preparing the conventional cytologic smear slide, the head of the sampler was detached and placed in a vial of fluid fixative. Paired slides were then prepared in the laboratory from the cells in the fluid fixative, using the CytoRich processing machine. The CytoRich and conventional cytologic smear slides were compared for quality, ease of screening, presence of endocervical cells, recognition of infections, and detection of squamous and glandular abnormalities. RESULTS: CytoRich slides were of much better quality, were easier to screen, had substantially fewer unsatisfactory results (0.3% vs. 2.6%) but lacked endocervical cells more often (16.1% vs. 10.6%). As regards abnormalities, the CytoRich slides showed fewer abnormalities, particularly in the low grade category. However, as a result of screening the paired CytoRich slide, some additional abnormalities were detected and a number of abnormalities reported on the conventional slide were reclassified (some to higher grades but more to negative). CONCLUSION: As an add-on technology, the CytoRich process has much to offer, in particular in the virtual elimination of unsatisfactory smears and in helping to resolve the difficult dichotomy between normal and low grade categories. Examining additional cellular material on a CytoRich slide enhances the sensitivity and accuracy of the combined results.

Cytodiagnosis↗
PubMed2001

Virtual colonoscopy: a novel imaging modality for colorectal cancer.

Advances in computed tomography (CT) technology and computer capabilities have contributed to the development of a new imaging modality for colorectal lesions called CT colonography or virtual colonoscopy. Virtual colonoscopy is a rapid, minimally invasive scan of the cleansed and distended colon. Early work has demonstrated that this test is safe and well tolerated, and that it may be sensitive and specific enough to identify most significant precancerous or cancerous lesions. A number of technical and practical problems remain before virtual colonoscopy can be applied at a population level.

Colonoscopy↗
PubMed2001

Impairment in motor learning of somatostatin null mutant mice.

Somatostatin was first identified as a hypothalamic factor which inhibits the release of growth hormone from the anterior pituitary (somatotropin release inhibitory factor, SRIF). Both SRIF and its receptors were subsequently found widely distributed within and outside the nervous system, in the adult as well as in the developing organism. Reflecting this wide distribution, somatostatin has been implicated regulating a diverse array of biological processes. These include body growth, homeostasis, sensory perception, autonomous functions, rate of intestinal absorption, behavior, including cognition and memory, and developmental processes. We produced null mutant mice lacking somatostatin through targeted mutagenesis. The mutant mice are healthy, fertile, and superficially indistinguishable from their heterozygous and wildtype littermates. A 'first round' phenotype screen revealed that mice lacking somatostatin have elevated plasma growth hormone levels, despite normal body size, and have elevated basal plasma corticosterone levels. In order to uncover subtle and unexpected differences, we carried out a systematic behavioral phenotype screen which identified a significant impairment in motor learning revealed when increased demands were made on motor coordination. Motor coordination and motor learning require an intact cerebellum. While somatostatin is virtually absent from the adult cerebellum, the ligand and its receptor(s) are transiently expressed at high levels in the developing cerebellum. This result suggests the functional significance of transient expression of SRIF and its receptors in the development of the cerebellum.

Animals↗
PubMed1997

Elf-2, a rhombotin-2 binding ets transcription factor: discovery and potential role in T cell leukemia.

Rhombotin-2 (RBTN-2) is a proto-oncogene only in the context of T lymphocytes. We postulated that the oncogenic effect of RBTN-2 in T cells is likely mediated by binding protein(s) with T cell-specific expression. By screening a T cell cDNA library, we identified a novel ets transcription factor that binds RBTN-2. This protein was named elf-2 because its DNA-binding domain is virtually identical to that of ets family member elf-1. Northern analyses showed similar levels of two elf-2 transcripts (3.5 kb and 3.8 kb) in all tissues except thymus. Thymocytes expressed four- to 10-fold greater amounts of the 3.5 kb transcript than other tissues. Sequence analyses of cDNA clones indicated that these transcripts encode proteins differing only at their amino termini, and likely represent alternatively spliced isoforms. These isoforms (elf-2a and elf-2b) contain identical RBTN-2 binding regions and DNA-binding domains. Elf-2b lacks a putative transactivation domain. The expression patterns suggest that RBTN-2 normally interacts equally with elf-2a and elf-2b. In contrast, when RBTN-2 is inappropriately expressed in T cells, RBTN-2 would interact predominantly with elf-2b; this interaction may lead to T cell proliferation.

Adaptor Proteins, Signal Transducing↗
PubMed2000

Which women should be tested for Chlamydia trachomatis?

OBJECTIVE: To assess the prevalence of genitourinary Chlamydia trachomatis infection among women in different clinical settings, with a view to making decisions about who should be tested routinely. DESIGN: Cross sectional study. SETTING: One regional hospital and family planning clinic serving an urban centre. Population Two thousand thirty-five sexually active women attending various outpatient settings. MAIN OUTCOME MEASURES: Prevalence of positivity by clinical setting, stratified by age. RESULTS: Overall, prevalence of lower genital tract chlamydial infection was similar in a variety of clinical settings. Infertile women were the only exception, demonstrating a much lower prevalence. Stratifying the study population by age found a clear trend towards high prevalence in teenagers and virtually no infection in women over the age of 30 years. CONCLUSIONS: The prevalence of chlamydial infection in women is related to age, regardless of clinical presentation. In practice, opportunistic screening should target sexually active women under 30 years of age.

Adolescent↗
PubMed2003

Detecting chloroquine retinopathy: electro-oculogram versus colour vision.

AIM: To investigate the relative sensitivity and specificity of two tests of retinal function (the electro-oculogram (EOG) and a computerised colour vision test) in screening for ocular toxicity caused by chloroquine and hydroxychloroquine. METHODS: 93 patients with rheumatic diseases receiving long term chloroquine and hydroxychloroquine therapy were followed for an average of 2.6 years. Clinical examination, an EOG, and a quantitative test of colour vision were carried out every 6 months. RESULTS: Mild fundus changes were observed in 38 patients. Four patients developed typical bull's eye maculopathy, three of whom had received 250, 365, and 550 g total dose of chloroquine, and one 1500 g of hydroxychloroquine. Statistical analysis of all patients showed that for those with no fundus changes or stippled pigmentation a number showed elevation of tritan threshold, so that if macular stippling is a sign of mild retinopathy the test on tritan changes has a 64% sensitivity and 63% specificity for an upper threshold value of 7%. All four patients with bull's eye lesions showed a marked disturbance of tritan colour vision, with a threshold of 14.8%, a sensitivity of 75%, and a specificity of 94%. For protan colour vision a threshold of 10% gives 75% sensitivity and 91% specificity. By contrast, neither an absolute nor a relative EOG reduction was a valid criterion for early or late chloroquine retinopathy. In advanced retinopathy an Arden coefficient (AQ) <180% yields 50% sensitivity and 54% specificity. When AQ <160% is the threshold, sensitivity does not increase but specificity rises to 82%. Occurrence of marked corneal deposits on clinical examination yields 50% sensitivity and 90% specificity in this situation. CONCLUSION: Screening for chloroquine retinopathy can be improved by using a sensitive colour test. Disturbance of the tritan axis appears to occur first. A normal test result on computerised colour testing virtually excludes any retinopathy by antimalarials. The EOG is of little diagnostic value.

Aging↗
PubMed1976

Laboratory diagnosis of rheumatoid arthritis: a solid phase radioassay for IgG and IgM antiglobulins.

A technique suitable for the routine estimation of IgM and IgG antiglobulins has been devised. The assay involves the binding of antiglobulins to plastic tubes coated with rabbit immunoglobulin: the amount of antiglobulin bound is then determined by adding radiolabelled antihuman IgG or IgM. The conditions for the assay have been examined and optimal incubation times and amounts of reagents established. Verification of the antibody nature of antiglobulin activity has been obtained. Both IgG and IgM antiglobulins were raised in virtually all seropositive rheumatoid arthritics, and most seronegative patients gave elevated values for either IgM or IgG rheumatoid factors. The use of an anti-light chain reagent as a screening test for total antiglobulins was investigated. These tests should prove valuable in diagnosis and permit quantitative evaluation of research studies.

Antibodies, Anti-Idiotypic↗