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PubMed2002

Emm types of invasive group A streptococcal isolates from Thai patients at King Chulalongkorn Memorial Hospital from 1995-1999.

Emm (M protein gene) typing was used to analyze group A streptococcal (GAS) clinical isolates in Thailand from in-patients at Chulalongkorn University Hospital (CUH) between January 1, 1995 and December 31, 1999. Forty GAS isolates were recovered from blood and other sterile sites from 40 patients presenting with different types of infections. A variety of emm sequences (24 types) have been reported in this study including the identification of 2 novel emm variants demonstrating the diverse population of invasive GAS isolates in Thailand. The common emm types include emm1 (5 isolates, 12.5%), emm22 (4 isolates, 10%), emm25 (3 isolates, 7.5%), emm61 (3 isolates, 7.5%), and STNS1033 (3 isolates, 7.5%). No particular emm types of GAS tend to be frequently associated with specific clinical presentation, complication, or anatomic site of infection. This report provides epidemiological information from Thailand where streptococcal infections and their sequelae are important public health problems. In addition, the results are useful for the development of a suitable M protein based vaccine in the future.

Adolescent↗

PubMed2003

[Development of a K562 multidrug-resistant cell line and study on proteins with altered expression].

In an attempt to study the whole protein expression alterations of tumer cells after becoming multidrug-resistant, which may provide useful information on new drug target identification, an adriamycin-resistant variant of the human leukemia cell line K562 (K562/ADR) was developed in vitro by continuous exposure to adrimycin. MTT assay was used to determine IC50 of K562/ADR cells to adriamycin (ADR), cisplatin (DDP), 5-fluorouracil (5-FU) and vincristin (VCR). The total proteins of K562 and K562/ADR were separated by two-dimensional gel electrophoresis and visualized by silver staining. Proteins with significant expression alterations were selected and their peptide mass fingerprints (PMFs) were obtained by matrix-assisted laser desorption/ionization time of flying mass spectrometry (MALDI-TOF-MS). The PMFs were used to search NCBInr database by AutoMS-Fit software. The results showed that K562/ADR cell demonstrated cross-resistance to other antineoplastic drugs. The IC50 of K562/ADR cells to ADR, DDP, 5-FU, VDR were much higher than those of K562. The proteins differentially expressed in the two cell lines were identified as cell cycle-related proteins, zinc finger protein 165, etc. These proteins are involved in cell cycling and transcription regulation, whose expression alterations may contribute to the multidrug resistant phenotype of K562/ADR cells.

Antineoplastic Agents↗

PubMed1991

Entrapment of the popliteal artery.

Although entrapment of the popliteal artery is uncommon, it is an important cause of arterial insufficiency in younger patients. Accurate diagnosis depends on a high index of suspicion combined with dynamic noninvasive testing and "stress angiography." Although angiographic demonstration of medial deviation of the artery is diagnostic, absence of this finding does not exclude the diagnosis of entrapment of the popliteal artery. Positional angiography may be necessary in these instances. Surgical exploration should be performed by a posterior approach, since this facilitates identification of the precise anatomic variant while allowing easy arterial repair, if necessary. The condition of the popliteal popliteal artery must dictate the extent of the surgical procedure. If the popliteal artery is normal, then relief of the constricting lesion alone will suffice. If the artery appears diseased or is thrombosed, then myotomy and arterial reconstruction must be performed. This is best accomplished by bypass grafting using autogenous vein or artery. If thromboendarterectomy is used, the clinician can expect a higher percentage of acute postoperative thromboses.

Adolescent↗

PubMed1989

Detection of bovine herpesvirus type 1 via an immunoperoxidase method, using monoclonal antibodies.

The sensitivity and specificity of the immunoperoxidase technique, using monoclonal antibodies, for the detection of bovine herpesvirus type 1 (BHV-1) was assessed and compared with viral isolation methods. In this study, BHV-1 antigens were detected in impression smears of brain obtained from calves in which BHV-1 was isolated. False-positive results were not observed after double-blind examination. Preliminary identification of isolates as antigenic variants was possible by use of 3 monoclonal antibodies reactive with neurotropic and/or pneumotropic strains of BHV-1. Results were consistent with previous work in which characterization was performed by use of immunofluorescense and ELISA. The immunoperoxidase technique, using monoclonal antibodies, was determined to be specific and sensitive, compared with viral isolation, for the diagnosis of BHV-1 encephalitis. In addition, it has operative advantages in that the assay does not require tissue culture facilities, and results can be obtained within hours after specimens are obtained.

Animals↗

PubMed1989

Occurrence and aetiology of acute respiratory diseases: results of a longterm surveillance programme.

Totals of 58,661,000 acute respiratory disease (ARD) cases, 1,376,651 bronchitis and pneumonia complications, and 93,042 deaths from influenza, bronchitis, pneumonia or chronic pulmonary affection were notified during 11 years of ARD surveillance from 1975 to 1986. All ARD seasons started with the first phase in September-December; this increase in morbidity was caused chiefly by adenoviruses, parainfluenza viruses, rhinoviruses and M. pneumoniae. Second wave of ARD morbidity occurring in January-April used to be explosive and was associated with an influenza epidemic in 9 of the 11 seasons; only in 1978/79 and 1984/85 the ARD epidemics were caused by adenoviruses and especially RSV, the share of influenza being minimal. Pneumonia and bronchitis excesses occured during epidemics caused by M. pneumoniae in 1975/76, 1980/81 and 1985/86. Particularly high mortality excesses occurred in 1976, 1977 and 1983 during epidemics elicited by a new drift variants of influenza A(H3N2). Identification of viral agent of M. pneumoniae attempted in 5474 ARD cases was successful at 37.4%. The respective contributions of parainfluenza viruses, adenoviruses, influenza A virus and RSV to overall aetiologically identified morbidity were 14.2, 13.9, 13.8, and 12.0%. Mixed infections (2-3 agents identified simultaneously) accounted for 14.6% of cases. Type B influenza virus, rhinoviruses, enteroviruses and herpes simplex virus contributed only by 5.6-7.8%. In ordinary seasons the share of M. pneumoniae in aetiologically identified ARD morbidity was 0.6-3.8%; this agent displayed predominance at 5-year cycles, when accounting for 20.5-38.9% of cases. The most frequently detected agents in individual age groups were as follows: in preschool children parainfluenza (18.6%), RSV (16.6%), and adenoviruses (17.4%); in school children M. pneumoniae (26%), influenza A and B (10.2 and 14.7% respectively), and adenoviruses (10.7%); in adolescents and young adults influenza type A (20.2%), M. pneumoniae (15.0%), and rhinoviruses (13.3%); in adults above 25 years age influenza A virus (38%), and other respiratory viruses at a frequency lower than 10% each.

Adolescent↗

PubMed1981

Origin of the triosephosphate isomerase isozymes in humans: genetic evidence for the expression of a single structural locus.

A genetic approach is used to ascertain that a single structural locus for triosephosphate isomerase (TPI) (E.C.5.3.1.1.) is expressed in rapidly dividing human lymphoblasts. This approach is made possible through the identification of a rare electrophoretic variant of human TPI. The variant phenotype is expressed by the TPI-B isozyme in both erythrocytes and peripheral lymphocytes. The variant phenotype is also expressed in the thermostability and electrophoretic pattern of the TPI-A isozyme in mitogen-stimulated lymphoblasts, indicating that TPI-A and TPI-B are products of the same structural locus. These findings are in contrast to the recent conclusions of Yuan et al. based upon structural analysis, suggesting that the TPI-A and TPI-B isozymes are products of distinct structural loci.

Carbohydrate Epimerases↗

PubMed1998

Alpha 1-antitrypsin phenotype of children with liver diseases in Thailand.

Alpha1-antitrypsin deficiency (PiZZ) constitutes not only the most common hereditary cause of liver diseases, but also of the most prevalent metabolic diseases in need of liver transplantation. It is a codominantly inherited disorder which predisposes to chronic liver disease, usually beginning in early infancy. The purpose of the present study has been to investigate alpha 1-antitrypsin phenotype in pediatric patients with various liver diseases. Phenotypic identification of alpha 1-antitrypsin variants has been carried out in 69 children with various liver diseases and 100 healthy controls using isoelectric focusing on polyacrylamide gel slabs. PIMM represents the most common phenotype detected in both groups (92% in the group with liver diseases and 88% in normal controls). We could detect PiZZ in only one healthy child but in none of those with liver diseases. Consequently alpha 1-antitrypsin deficiency does not appear to be a common cause for liver disease among children in Thailand. Further studies are necessary to elucidate the frequency of various alpha 1-antitrypsin variants and the clinical relevance with respect to liver diseases in Thailand.

Child↗

PubMed1994

[A rapid and simple method for direct genotype determination of ABO blood group].

We report the use of an allele-specific polymerase chain reaction (ASPCR) format together with low melting temperature agarose gel electrophoresis which allows rapid identification of the six major genotypes of the ABO blood group. Four sequence specific primer sets, each specific for a different set of ABO alleles, were used. Twenty individuals, whose ABO genotypes were previously determined by serological and family analysis, were typed with this new approach. A 100% correlation between serology and the ASPCR was found. This method is rapid, simple, and reproducible. Potential applications include identification of ABO subgroups and variants, paternity testing, as well as forensic science.

ABO Blood-Group System↗

PubMed2003

c-Met expression in tall cell variant papillary carcinoma of the thyroid.

BACKGROUND: Tall cell variant papillary carcinoma of the thyroid demonstrates unusually aggressive clinical behavior compared with the usual form of papillary thyroid carcinoma. The proto-oncogene c-met encodes a tyrosine kinase receptor known to influence cell invasion. This current study examined c-Met expression in tall cell variant tumors compared with other types of papillary thyroid carcinoma and benign thyroid disease. METHODS: c-Met expression in 60 archived thyroid specimens was evaluated by immunohistochemical staining. RESULTS: Tall cell variant specimens expressed significantly greater levels of c-Met than other forms of papillary thyroid carcinoma and benign thyroid disease (P < 0.0001). c-Met expression was significantly different for the following pairs of histologies: tall cell variant versus usual papillary carcinoma of the thyroid (P < 0.0001), tall cell variant versus follicular variant papillary thyroid carcinoma (P < 0.0001), tall cell variant versus benign thyroid (P < 0.0001), and usual papillary carcinoma of the thyroid versus benign thyroid (P = 0.005). In addition, for all types of papillary carcinomas evaluated, c-Met expression was significantly higher in specimens with extracapsular spread (P = 0.01) and skeletal muscle invasion (P = 0.02), and approached significance for specimens with lymphatic invasion (P = 0.06). After adjusting for extracapsular spread, c-Met expression was still found to be associated significantly with tall cell histology (P < 0.0001). CONCLUSIONS: c-Met expression is a significant marker for tall cell variant papillary carcinoma of the thyroid and its invasive behavior. This finding may explain the unusually aggressive behavior of this tumor and suggests a role for c-Met in the early identification of patients with tall cell variant thyroid disease.

Adult↗

PubMedDate not supplied

Genes and type 2 diabetes mellitus.

Type 2 diabetes (T2DM) comprises a group of entities with different genetic causes. In most patients, T2DM results from alterations of various genes, each having a partial and additive effect. The inheritance pattern is thus complex, and environmental factors play an important role in favoring or delaying the expression of the disease. The identification of susceptibility genes and genetic variants requires different methodological approaches. Here we address some of the most important strategies and findings on the genomic basis of T2DM, as well as evidence of genetic heterogeneity among populations. The identification of the underlying genetic causes of T2DM and other related traits such as obesity and hypertension will lead to the development of new therapeutic targets likely to impact the way we treat these diseases. Survival and quality of life for T2DM patients is expected to eventually increase, significantly lessening the socioeconomic burden of the disease.

Alleles↗

PubMed2025

Genomic testing for RET in the clinic: UK and global perspective.

RET is a key oncogene in neuroendocrine cancer. Pathogenic germline variants lead to multiple different phenotypes, including multiple endocrine neoplasia type 2, medullary thyroid cancer (MTC), Hirschsprung disease and kidney malformations. Pathogenic somatic variants are also associated with MTC, and RET rearrangements are observed in papillary thyroid cancer, non-small cell lung cancer and pan-cancer syndromes. Testing for both germline and somatic variants is now feasible in everyday clinical practice, and their identification has important clinical consequences, both for affected individuals and their families. This mini-review will discuss current germline and somatic testing strategies in the UK and worldwide, as well as reporting and test outcomes (including variants of uncertain significance or incidental findings). It will explore actions following identification of a pathogenic germline variant, including predictive, reproductive and childhood testing, and somatic testing of RET variants in solid tumours informing personalised cancer treatment. Finally, it will discuss the challenge of delivering rapid and equitable access to genomic testing to ensure that all individuals can benefit promptly and appropriately to improve clinical outcomes.

Humans↗

PubMed2004

Outbreak of infection with hepatitis A virus (HAV) associated with a foodhandler and confirmed by sequence analysis reveals a new HAV genotype IB variant.

An outbreak of infection with hepatitis A virus associated with a foodhandler and involving 26 subjects occurred in Southern Italy. Sequence analysis of the VP3-VP1 and VP1-P2A junctions confirmed that the outbreak was due to a point source and allowed the identification of a new genotype IB variant. This report confirms the usefulness of sequence-based molecular fingerprinting during outbreaks.

Amino Acid Sequence↗

PubMed2004

HPLC retention time as a diagnostic tool for hemoglobin variants and hemoglobinopathies: a study of 60000 samples in a clinical diagnostic laboratory.

BACKGROUND: Previous evaluations of HPLC as a tool for detection of hemoglobin variants have done so within newborn-screening programs and/or by use of stored samples. We describe a 32-month prospective study in a clinical diagnostic laboratory in which we evaluated the imprecision of HPLC retention times and determined the retention times for hemoglobin variants seen in a multiethnic setting. METHODS: We analyzed all samples on the Bio-Rad Variant II HPLC system. For normal hemoglobin fractions and hemoglobin variants, we recorded and analyzed their retention times, their proportion of the total hemoglobin (%), and the peak characteristics. We compared the imprecision of retention time with the imprecision of retention time normalized to the retention time of hemoglobin A0 (Hb A0) and to the retention time of Hb A2. Alkaline and acid hemoglobin electrophoresis, and in certain cases globin chain electrophoresis, isoelectric focusing, and DNA analysis, were performed to document the identities of the hemoglobin variants. RESULTS: The mean (SD) imprecision (CV) of the retention time was 1.0 (0.7)% with no statistical difference compared with the imprecision for normalized retention times. Among 60,293 samples tested, we encountered 34 unique hemoglobin variants and 2 tetramers. Eighteen variants and 2 tetramers could be identified solely by retention time and 3 variants by retention time and proportion of total hemoglobin. Four variants could be identified by retention time and peak characteristics and eight variants by retention time and electrophoretic mobility. One variant (Hb New York) was missed on HPLC. Retention time on HPLC was superior to electrophoresis for the differentiation and identification of six members of the Hb J family, four members of the Hb D family, and three variants with electrophoretic mobilities identical or similar to that of Hb C. Six variants with electrophoretic mobilities identical or similar to that of Hb S could be differentiated and identified by retention time and proportion of total hemoglobin. HPLC detected two variants (Hb Ty Gard and Hb Twin Peaks) missed on electrophoresis. CONCLUSIONS: The retention time on HPLC is reliable, reproducible, and in many cases superior to conventional hemoglobin electrophoresis for the detection and identification of hemoglobin variants. Confirmatory testing by electrophoresis can be eliminated in the majority of cases by use of retention time, proportion of total hemoglobin, and peak characteristics of HPLC.

Chromatography, High Pressure Liquid↗

PubMed1996

Detection of haemoglobin variants for the diagnosis of beta thalassaemia & other haemoglobinopathies using anion exchange high performance liquid chromatography.

We describe the precise identification, separation and quantitation of several haemoglobin (Hb) variants such as Hbs A2, A, F, S, E, J, H, D-Punjab and Q-India in untransfused patients with beta thalassaemia and other haemoglobinopathies prevalent in the Indian population using whole blood (5 microliters), red cell lysates (2 microliters) or dried blood specimens on filter paper, using a conventional anion exchange high performance liquid chromatography (AX-HPLC) system. Samples were simultaneously studied for the presence of haemoglobin variants by alkaline electrophoresis. The problems in analysing rare variants and separating the closely migrating variants, encountered in the conventional methods could be resolved using the HPLC technique.

Adult↗

PubMed2004

Identification and cloning of genes displaying elevated expression as a consequence of metastatic progression in human melanoma cells by rapid subtraction hybridization.

Although extensively investigated, the complete repertoire of genes associated with and causative of metastasis remain largely unknown. We developed an efficient approach for identifying differentially expressed genes that involves rapid subtraction hybridization (RaSH) of cDNA clones prepared from two cell populations, a driver and a tester. This RaSH approach has previously documented high sensitivity and effectiveness in identifying genes that are differentially expressed as a function of induction of terminal differentiation in human melanoma cells, resistance or sensitivity to human immunodeficiency virus-1 (HIV-1) infection of human T cells and perturbation in gene expression in normal human fetal astrocytes infected with HIV-1 or treated with HIV-1 gp120 viral envelope glycoprotein or tumor necrosis factor-alpha (TNF-alpha). In the present study, RaSH has been applied to a metastatic melanoma model, which mimics the early events of metastasis in humans, comprising weakly metastatic vs. immunosuppressed newborn rat-selected highly metastatic variants. This has now resulted in the identification of eight genes displaying elevated expression in the high metastatic variants vs. normal immortal melanocytes or weakly metastatic parental clones. These include six known genes, 67-kDa laminin receptor (67LR), endothelin receptor B (ENDRB), Na+/K+-ATPase, Ku antigen, interleukin-receptor-associated kinase-1 (IRAK-1) and ribosomal protein RPLA, which may contribute to the complex process of melanoma metastasis. Additionally, two unknown genes (not reported in current databases) that may also impact on the metastatic phenotype have also been identified. These studies provide additional support of the use of the RaSH approach, in this application in the context of closely related variant cell lines with different metastatic potential, for effective differential gene identification and elucidate eight previously unrecognized genes whose role in melanoma progression to metastatic competence can now be scrutinized.

Animals↗

PubMed2026

Utilization of long-read sequencing for the detection of structural rearrangements with AgileStructure.

MOTIVATION: Changes in genome organisation contribute to genetic disease when they disrupt gene function or regulation. Structural rearrangements may interrupt coding sequence or alter expression through promoter loss or gain, chromatin changes, copy-number variation, or disruption of short-range regulatory elements. Although short-read sequencing excels at detecting small variants, it performs poorly at resolving breakpoints of large rearrangements, especially in repetitive or low-complexity regions. Long-read sequencing overcomes these limitations, but analytical tools have not kept pace, making accurate identification and annotation of large structural variants challenging. RESULTS: We developed AgileStructure, a desktop application for locating and annotating large‑scale genomic rearrangements using aligned long‑read data. The software enables user‑guided exploration of breakpoint‑spanning reads, supporting accurate interpretation of complex events and filling a key gap in current structural variant analysis workflows. AVAILABILITY AND IMPLEMENTATION: Source code, binaries, user guide, and example aligned read data, are available on GitHub: https://github.com/msjimc/AgileStructure. An archived version is also available on Zenodo at https://doi.org/10.5281/zenodo.18610110.

Software↗

PubMed2004

Variant Creutzfeldt-Jakob disease: risk of transmission by blood and blood products.

Variant Creutzfeldt-Jakob disease (CJD) is a novel acquired human prion disease apparently resulting from exposure to the bovine spongiform encephalopathy (BSE) agent. Variant CJD differs from other human prion diseases in that the disease-associated form of the prion protein and infectivity are readily detectable in lymphoid tissues throughout the body. Lymphoid tissues and lymphocytes are implicated in the peripheral pathogenesis of prion diseases (where infectivity may be detected during the preclinical phase of the illness), giving rise to concerns that blood and blood products may also contain infectious particles, representing a possible source of iatrogenic spread of variant CJD. This concern has been reinforced following the experimental transmission of BSE in a sheep model by transfusion of blood and buffy coat from animals in the preclinical phase of the illness, and the recent identification of a UK case of variant CJD in a patient who had received packed red blood cells that had been donated by an individual who subsequently died from variant CJD. Studies in animal models suggest that most prion infectivity in blood may be cell-associated, with lower levels in the plasma, and there is evidence to suggest that any infectivity present may be reduced during the process of plasma fractionation. However, the possibility that plasma or blood products could transmit the disease cannot be excluded. Further studies are required to develop more sensitive means to detect disease-associated prion protein in blood; such techniques could be employed for screening purposes to reduce exposure to contaminated products and to assist with risk management in potentially exposed individuals.

Blood Coagulation Factors↗

PubMed2002

The genetic basis of dyslexia.

Dyslexia, a disorder of reading and spelling, is a heterogeneous neurological syndrome with a complex genetic and environmental aetiology. People with dyslexia differ in their individual profiles across a range of cognitive, physiological, and behavioural measures related to reading disability. Some or all of the subtypes of dyslexia might have partly or wholly distinct genetic causes. An understanding of the role of genetics in dyslexia could help to diagnose and treat susceptible children more effectively and rapidly than is currently possible and in ways that account for their individual disabilities. This knowledge will also give new insights into the neurobiology of reading and language cognition. Genetic linkage analysis has identified regions of the genome that might harbour inherited variants that cause reading disability. In particular, loci on chromosomes 6 and 18 have shown strong and replicable effects on reading abilities. These genomic regions contain tens or hundreds of candidate genes, and studies aimed at the identification of the specific causal genetic variants are underway.

Animals↗