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PubMedDate not supplied

Isolated pleural fluid lactic dehydrogenase level: a cost effective way of characterizing pleural effusions.

BACKGROUND: Characterization of pleural effusion into an exudate or transudate is usually the first step in diagnostic evaluation. Light's criteria have been universally accepted as gold standard in this regard. We wanted to see the utility of isolated pleural fluid lactic dehydrogenase level (representing one of Light's classical criteria) in characterizing pleural effusion in our setting. We also wanted to compare the accuracy of commonly used conventional criteria with Light's criteria of isolated pleural fluid lactic dehydrogenase. METHODS: Patients who underwent diagnostic thoracentesis for one-year period were studied. Characterization of pleural effusions using biochemical criteria including pleural fluid protein, lactic dehydrogenase level (LDH), red blood cell (RBC) count and white blood cell (WBC) count were identified and compared with predetermined clinical criteria (gold standard). For each biochemical criteria sensitivity, specificity, positive predictive value and negative predictive value were calculated. RESULTS: Sixty-two patients underwent diagnostic thoracentesis. Sixteen were excluded, as they did not fulfill predetermined clinical criteria. Eight patients had transudative effusion vs. 38 exudates. LDH was found to be the most sensitive (97.2%) while WBC > 1000/mm3 was the most specific (100%) of all the criteria looked at. The overall accuracy was highest for Light's criteria of isolated LDH > 200 IU/litre (95.6%) followed by pleural fluid protein, WBC count and RBC count. CONCLUSION: We conclude that isolated pleural fluid LDH, as a representative of classical Light's criteria, is the most accurate criteria for characterizing pleural effusions. Due to its low accuracy isolated pleural fluid protein should not be ordered routinely. This approach may result into potential cost savings in our economically restraint society.

Clinical Enzyme Tests↗

PubMed1992

Immunohistochemical characterization of amyloid proteins in sural nerves and clinical associations in amyloid neuropathy.

To test whether immunohistochemical characterization of proteins in amyloid deposits in biopsied sural nerves gives reliable and useful diagnostic information using commercially available reagents, biopsy specimens of sural nerves from 38 patients with amyloid neuropathy were studied. Transthyretin (TTR) was detected in the amyloid deposits of 11 nerves, lambda light chains (LC) in 8 nerves, kappa LC in 7 nerves, and both lambda and kappa LC in 3 nerves. In 9 nerves, the amyloid deposits were too small to allow adequate immunohistochemical characterization of amyloid proteins in serial sections. Evidence that immunohistochemical characterization was correct came from: 1) evaluation of kin, 2) search for monoclonal proteins in the plasma, and 3) sequencing of the gene abnormalities in TTR+ cases. In 9 of 11 TTR+ cases, in which DNA could be obtained, sequencing of the gene showed that each of the 9 cases was heterozygous for a gene mutation; 7 had previously described mutations and 2 undescribed mutations. Therefore, in the nine sporadic cases without plasma monoclonal light chains, the immunohistochemical characterization correctly identified the protein in amyloid as transthyretin. Likewise, there was a high concordance between immunoglobulin light chains in plasma and light chains in amyloid in primary amyloidosis. Evaluation of the type, distribution, and severity of the neurologic symptoms and deficits showed: 1) the sensorimotor and autonomic neuropathy of amyloidosis characteristically affects proximal as well as distal limbs, and 2) the type of amyloidosis probably cannot be determined from the characteristics or severity of the neuropathy alone or from the location or size of amyloid deposits in nerve.

Aged↗

PubMedDate not supplied

Evaluation of automated ribotyping system for characterization and identification of verocytotoxin-producing Escherichia coli isolated in Japan.

The usefulness of an automated ribotyping system (RiboPrinter) was evaluated for characterizing and identifying clinical isolates of 37 verocytotoxin-producing Escherichia coli (VTEC) strains and 16 non-VTEC strains. All strains were successfully ribotyped with satisfactory reproducibility and stability and characterized into 10 different ribogroups. All VTEC O157 strains were characterized into a specific ribogroup and correctly typed into the specific DuPont ID for VTEC O157:H7, while all of the non-VTEC O157 strains were clearly distinguished from VTEC O157. VTEC O26 and O111 strains, the most prevalent VTEC serotypes after O157, were also well characterized into specific ribogroups and identified. These results suggest that the RiboPrinter may have an advantage over other typing systems in that it can rapidly and easily discriminate VTEC from non-VTEC strains of the most prevalent VTEC serotypes in Japan, even though it provides a lesser degree of discrimination than pulsed-field gel electrophoresis (PFGE). With a hierarchical or sequential typing combining the RiboPrinter and PFGE, rapid and accurate typing can be achieved during an outbreak of VTEC, which may be useful in clinical and public health settings.

Automation↗

PubMed1992

Introduction to the issues: recently developed methods for characterizing cell lines.

Cell line characterization is an integral part of establishing quality control over the manufacturing process of a biological product. Characterizing the general and unique features of the continuous cell line and the absence or presence of contaminants establishes a fundamental knowledge about the raw material from which the biological product is being derived. Such information can be used for cell line selection, design of the purification scheme and extent of ensuing validation studies. Developing the selected cell line into a cell bank system allows for a constant source of starting material and decreases the likelihood of contamination. Characterization of the cell bank system may include a) identification of the cell line species of origin, b) identification of unique reference markers, and c) pre-testing for cross-contamination and adventitious agents. This paper introduces issues surrounding present and upcoming methods used for authenticity and characterization testing of cell banks.

Animals↗

PubMed2004

Characterization of RUSC1 and RUSC2 genes in silico.

We have previously cloned (or identified) and characterized novel genes encoding SH3 domain proteins, such as MAP3K10, FNBP1L, FNBP2, FCHSD1, FCHSD2, LASP2 and MPP7. During characterization of SH3 domain molecules, we found the existence of an N-terminally- truncated 433-aa RUSC1 protein (NP_055143.2). Here, we characterized RUSC1 and RUSC2 genes by using bioinformatics. IMAGE 5204626 (BC025680.1) and KIAA0375 (AB002373.2) were representative cDNAs derived from human RUSC1 and RUSC2 genes, respectively. 2210403N08 (AK039664.1) and MGC73483 (BC056360.1) cDNAs were derived from mouse Rusc1 gene, while Kiaa0375 (AK122263.1) cDNA was derived from mouse Rusc2 gene. RUSC1 gene, consisting of 11 exons, was mapped to human chromosome 1q22. RUSC2 gene, consisting of 12 exons was mapped to human chromosome 9p13. Human RUSC1 gene as well as mouse Rusc1 gene were found to encode two isoforms with or without 411-bp exon 3 due to alternative splicing of exon-skipping type. RUSC1 isoform 1 (1039 aa) and RUSC2 (1516 aa) showed 30.5% total amino-acid identity. Human RUSC1, RUSC2, mouse Rusc1 and Rusc2 proteins were found to share the common domain structure, consisting of RUN, Leucine zipper, and SH3 domains. RUSC1, RUSC2, RIPX, RUFY1, RUFY2, RUTBC1, RUTBC2, RUTBC3, RUB6IP1, and PLEKHM1 were RUN domain proteins within the human proteome. This is the first report on comprehensive characterization of RUSC1 and RUSC2 orthologs.

Adaptor Proteins, Signal Transducing↗

PubMed2005

Immunophenotypic characterization of high grade pleomorphic sarcomas: a demographic and immunohistochemical study in a major referral center of Pakistan.

OBJECTIVE: Immunophenotypic characterization of high grade (pleomorphic) sarcomas and determination of their frequency, mean/median age, sex preferences and common sites in Pakistani patients. METHODS: This study included 134 consecutive cases of high grade (pleomorphic) sarcomas diagnosed in adults above the age of 15 years in the section of histopathology at theAga Khan University Hospital, Karachi during a period of two years. These high grade (pleomorphic) sarcomas were immunophenotyped using a panel including antibodies against Vimentin, Desmin, Smooth muscle Actin, S 100, CD34, CD68 and Cytokeratin etc by indirect immunoperoxidase. RESULTS: Of the 134 cases which were characterized, 38.1% were pleomorphic leiomyosarcoma, followed by pleomorphic rhabdomyosarcoma 14.9%, Malignant Peripheral Nerve Sheath Tumour 9%, pleomorphic liposarcoma 3.7% and pleomorphic storiform Malignant Fibrous Histiocytoma 0.7%. Thirty three percent of cases could not be characterized further. Mean/ median age for Leiomyosarcoma was 50/50, for Rhabdomyosarcomas 33/22, for MPNST 42/41, for Liposarcoma 52/50 and for Malignant Fibrous Histiocytoma 46/46 respectively. The commonest site for leiomyosarcoma was lower limb (43%), for rhabdomyosarcoma head and neck (42%), for MPNSTthorax (36.4%) and for liposarcoma abdomen (50%). CONCLUSION: It was concluded that the most common pleomorphic sarcoma occurring in our adult population was Leiomyosarcoma, and that immunohistochemical stains are essential in most cases for further characterization of pleomorphic high grade sarcoma.

Adult↗

PubMed2005

Genetic characterization of European-Zebu composite bovine using RFLP markers.

A population of 370 European-Zebu composite beef heifers, consisting of six different breed compositions (A-F), were characterized genetically, using RFLP markers of luteinizing hormone receptor (LHR) and follicle-stimulating hormone receptor (FSHR) genes. Our objectives were to genetically characterize this population and to determine the structure and the genetic variability of this hybrid herd. The genotypes were determined through PCR, followed by digestion with restriction endonucleases. The PCR-RFLP analysis made it possible to identify the LHR and FSHR genotypes, as well as to characterize the degree of heterozygosis, which was high for all of the breed compositions, for both loci, except for two combinations for LHR (B and C). The observed heterozygosity (Ho) was lower than the expected heterozygosity (He) for compositions C (for LHR) and A and D (for FSHR); however, for the population as a whole, Ho was above He (with a mean of 57 versus 46%, respectively), reflecting the elevated genetic variability in this population and also the informative value of the RFLP markers, which could be useful for population genetic characterization studies. The analysis of the degree of genetic structure of this population, estimated by the Nei's statistic, for both loci, indicated an elevated total genetic diversity (HT = 47%), with most of this variability being due to intrapopulational diversity (HS = 46%), with a low degree of genetic differentiation among the six breed compositions (GST = 1.2%). The estimates generated by the Wright's F statistic indicated a non-endogamic population, with excess heterozygotes (FIT = -0.22), which was also observed at the intrapopulational level (FIS = -0.23). The results gave evidence that the genetic selection applied to this European-Zebu composite population did not affect the expected high genetic variability for this type of crossbreeding, which makes it possible to use these animals to obtain economically valuable productive and reproductive traits.

Alleles↗

PubMed2005

Characterization of an immune response.

The characterization of any detected antibodies provides detailed information that can be critical to understanding the significance of an immune response. The BIAcore immunoassay provides a straightforward means of characterizing many aspects of the immune response including antibody concentration, specificity, binding affinity, and the presence of isotypes. One important aspect of the immune response is determination of neutralizing capability, which requires a biological assay. The ultimate clinical significance of an immune response can only be fully understood when data from antibody characterization are coupled with clinical data from the patient. Some of the factors that can contribute to the clinical significance of an immune response are: (i) magnitude of the immune response (concentration of antibodies detected); (ii) duration of the immune response (continuous antibody production or sporadic and not sustained); (iii) correlation with any adverse events; (iv) correlation with a change in pharmacokinetics (either mediating sustained circulation or enhanced clearance of the drug); (v) biological neutralization of the drug; (vi) biological neutralization of an endogenous protein. Full characterization of the immune response requires the incorporation of antibody assays, pharmacokinetic assays, and clinical data.

Animals↗

PubMed2005

Characterization of gene therapy products and the impact of manufacturing changes on product comparability.

Gene therapy products represent a novel and complex class of products. Ensuring product safety, identity, purity and potency following a manufacturing change extends not only to assessing the final formulated product but also all the components used during product manufacturing. CBER has implemented a stepwise approach to product characterization and compliance with cGMPs, which increases as the study moves from phase 1 toward phase 3 and licensing. It is important that product characterization be performed early in product development because without full product characterization it will be difficult to determine the impact of the manufacturing process on the product as well as the impact any manufacturing change will have on the product. To demonstrate product comparability a thorough understanding of the manufacturing process, including product characterization, is necessary, so that the impact of a manufacturing change can be accurately assessed.

Animals↗

PubMed2005

[Molecular genetic characterization of genus Echinococcus.].

Morphological, biological and epidemiological features of the adult and metacestode stage of the genus Echinococcus have been the most frequently used criteria for the characterization of species. But strain characterization is more complex and is based on the morphological, biological, biochemical, epidemiological and molecular features. Although morphological and biological studies have provided extremely useful information for strain characterization, that these features may be variable must be taken into consideration. They may be influenced by host and environmental factors and may not reflect distinctness at a genetic level. Although, conventional techniques may be affected by the environment or host, molecular techniques allow a direct characterization of the genome of the parasite and they are not affected by environmental factors. In this review, various data concerning molecular typing methods of the genus Echinococcus have been summarized.

English Abstract↗

PubMed1989

Isolation and characterization of rat cytochrome P-450IIB gene family members. Use of the polymerase chain reaction to detect expression of a novel P-450 mRNA.

The rat cytochrome P-450IIB gene family consists of at least 10 members, 2 of which, P-450b and P-450e, have been well characterized and are activated transcriptionally by phenobarbital (PB) in the liver. The remaining genes in this family have not been studied extensively. In this report, data are presented that provide additional characterization of a P-450IIB gene, termed gene IV. The complete gene IV and flanking regions were isolated from a rat liver Charon 4A genomic library and subjected to a variety of analyses. Structural homology to the P-450b gene was confirmed by comparative restriction mapping and high stringency hybridization of gene IV fragments to probes comprising the entire cDNA for P-450b. The 5'-portion of gene IV, including its flanking region, was sequenced and contained an open reading frame for 58 amino acids which were 62% related to exon 1 of the P-450b/e genes. Typical TATA and CAAT promoter elements, as well as two Sp1 core sequences and a site related to a glucocorticoid responsive element were found in gene IV. Northern blot studies with an oligomer probe specific to gene IV sequence indicated a 4.3-kilobase pair polyadenylated transcript present at low levels in untreated rat liver and inducible approximately 6-fold by PB treatment. Primer extension experiments indicated that the transcription initiation site mapped to a position on gene IV that was analogous to that reported for the structurally similar P-450e gene. Due to the low levels of hepatic RNA expression, we employed the polymerase chain reaction to facilitate characterization of gene IV transcripts. The polymerase chain reaction data verified that gene IV transcripts were elevated after PB treatment. Significantly, the polymerase chain reaction results demonstrated that gene IV transcripts were associated with hepatic polysome fractions, indicating their active utilization in this tissue. Polymerase chain reaction analysis of RNA also indicated constitutive expression of gene IV transcripts in rat lung, kidney, and testis, as well as fetal rat liver. Together, these data show that gene IV is a transcribed member of the P-450IIB gene family and, like the well characterized P-450b and P-450e genes, is positively regulated by PB in rat liver.

Animals↗

PubMed1985

[Characterization of gastric carcinoma viewed from the primary cancer site].

Character of gastric carcinoma is closely related to the location and the primary site. The 679 cases of gastric carcinoma, curatively resected eleven year period, were studied for the relationship between the primary site and the character. The lower portion of the stomach (A) was characterized by large numbers of protruded type of early cancer, localized type of advanced cancer, and intestinal type histologically. The middle portion of the stomach (M) was characterized by large numbers of depressed type of early cancer, infitrative type of advanced cancer, and diffuse type histologically. The cancer of upper portion (C) involving 2 or 3 portions was characterized by large numbers of infitrative type of advanced cancer. In general, the ratio of intestinal type to diffuse type became inverted in the forties, and percentage of intestinal type increased by aging. In the advanced cancer of the upper portion, the invasion of the ratio occurred in the late fifties. Intestinal metaplasia and changing F-line of the gastric mucosa by aging is thought to be background factors of such characterization of gastric carcinoma.

Adenocarcinoma↗

PubMed1980

Poliovirus strain characterization: a WHO memorandum.

Reliable laboratory techniques for the intratypic characterization of poliovirus types 1, 2, and 3 isolates have an important role in the epidemiological surveillance of poliomyelitis and in studies of the safety and efficacy of poliovirus vaccines. Of the techniques available for poliovirus strain characterization, those potentially most useful are intratypic serodifferentiation and the biochemical techniques. The value of strain-specific (absorbed) antisera for antigenic characterization of strains has been clearly established for the identification of both vaccine-like viruses and different epidemic wild strains. Single-radial-diffusion techniques appear to be promising and should be further explored. Biochemical techniques involving studies of both virus polypeptides and nucleic acids are also capable of providing valuable information for strain characterization. Biological and physico-chemical tests are generally of limited value but their application may be useful in certain circumstances.

Epitopes↗

PubMed1995

Engrafted maternal T cells in a severe combined immunodeficiency patient express T-cell receptor variable beta segments characterized by a restricted V-D-J junctional diversity.

To better understand the peculiar functional behavior of engrafted maternal T cells in a severe combined immunodeficiency (SCID) patient, we characterized, at the molecular level, the T-cell repertoire of a SCID child with a high number of engrafted, mature, activated lymphocytes. We found that, although these transplacentally acquired T cells express a random set of T-cell receptor variable beta (TCRBV) segments, the TCRBV transcripts are characterized by an extremely restricted V-D-J junctional diversity. Only a few cDNA clones were dominant among the TCRBV4+, TCRBV6+, and TCRBV20+ populations in engrafted cells, whereas the same TCRBV chains expressed by the mother's lymphocytes had the expected junctional hetero-geneity. Highly diverse and polyclonal junctions were also expressed by maternal cells activated in mixed lymphocyte reaction by Epstein-Barr virus (EBV)-transformed B lymphocytes from the patient, indicating that the strong clonal selection that characterizes the engrafted cells repertoire is probably not due to allorecognition. Furthermore, we report that the repertoire of the transplacentally acquired lymphocytes is dynamic over time and is characterized by waves of expression and contraction of selected clones, expressing different TCRBV segments. These results help to explain some of the abnormal functional behaviors of engrafted maternal cells and raise new questions regarding the mechanisms responsible for the restricted clonal diversity.

Amino Acid Sequence↗

PubMed1996

Characterization of 12 silent alleles of the human butyrylcholinesterase (BCHE) gene.

The silent phenotype of human butyrylcholinesterase (BChE), present in most human populations in frequencies of approximately 1/100,000, is characterized by the complete absence of BChE activity or by activity <10% of the average levels of the usual phenotype. Heterogeneity in this phenotype has been well established at the phenotypic level, but only a few silent BCHE alleles have been characterized at the DNA level. Twelve silent alleles of the human butyrylcholinesterase gene (BCHE) have been identified in 17 apparently unrelated patients who were selected by their increased sensitivity to the muscle relaxant succinylcholine. All of these alleles are characterized by single nucleotide substitutions or deletions leading to distinct changes in the structure of the BChE enzyme molecule. Nine of the nucleotide substitutions result in the replacement of single amino acid residues. Three of these variants, BCHE*33C, BCHE*198G, and BCHE*201T, produce normal amounts of immunoreactive but enzymatically inactive BChE protein in the plasma. The other six amino acid substitutions, encoded by BCHE*37S, BCHE*125F, BCHE*170E, BCHE*471R, and BCHE*518L, seem to cause reduced expression of BChE protein, and their role in determining the silent phenotype was confirmed by expression in cell culture. The other four silent alleles, BCHE*271STOP, BCHE*500STOP, BCHE*FS6, and BCHE*I2E3-8G, encode BChES truncated at their C-terminus because of premature stop codons caused by nucleotide substitutions, a frame shift, or altered splicing. The large number of different silent BCHE alleles found within a relatively small number of patients shows that the heterogeneity of the silent BChE phenotype is high. The characterization of silent BChE variants will be useful in the study of the structure/function relationship for this and other closely related enzymes.

Alleles↗

PubMed1997

Characterization and establishment of specifications for biopharmaceuticals.

This paper describes the role of product characterization and product specifications in the context of an overall control strategy. Due to advances in analytical characterization and biotechnology manufacturing methods, product characterization can now be used as an effective means of assessing the impact of manufacturing process changes on product quality, safety and efficacy, hence obviating the need for repeating clinical testing each time a manufacturing process change is made. The ICH specifications guidance document can serve a key role in harmonising test requirements and regulatory practices with regard to produce characterization. Consumers, regulatory agencies, and biopharmaceutical manufacturers all stand to benefit from this harmonization process.

Biopharmaceutics↗

PubMed1998

[Obtention and characterization of murine beta-NGF. Application in a model of cerebral aging].

INTRODUCTION: beta-NGF is a basic protein of 118 aminoacids which acts are a trophic factor for sensory and sympathetic neurons of the peripheral nervous system, and on cholinergic neurons of the anterior basal cerebrum. OBJECTIVES: In view of the functional effect of beta-HGF and its possibilities as a therapeutic agent in neurodegenerative disease, including Alzheimer's disease in this study our aim was to obtain, characterize and show the main results of the application of beta-NGFm in a model of cerebral ageing in rats with cognitive disorders. MATERIAL AND METHODS: For the obtention of beta-NGFm we followed Mobley's method as modified by Ebendal and used mouse submaxillary gland as a source of raw material. The characterization studies were carried out by application of seven techniques which allowed physicochemical characterization and demonstration of the biological activity of the product. Application of beta-NGF obtained under these conditions was carried out in a mode of cerebral ageing and the effects of treatment were assessed by conduct studies, measurement of the activity of the enzyme acetyl cholinesterase and study of neural plasticity. CONCLUSIONS: Characterization studies carried out on the beta-NGFm showed that the protein obtained consists of a mixture of molecules of beta-NGFm which are intact at their extreme N-Terminal, and molecules which have lost the octapeptide of the N-terminal position and show some modification increasing hydrophobicity. All these species were recognized immunologically by the specific antibody anti-NGFm and showed biological activity.

Aging↗

PubMed1998

Proposals for the characterization and description of new human leukemia-lymphoma cell lines.

Continuous human leukemia-lymphoma cell lines have become invaluable tools for hematological research as they provide an unlimited amount of cellular material. The first human lymphoma cell line Raji was established in 1963; since then several hundred leukemia-lymphoma cell lines spanning almost the whole spectrum of hematopoietic cell lineages (except for dendritric cells) have been described. The cardinal features of leukemia-lymphoma cell lines are their monoclonal origin, arrest of differentiation, and (growth factor-independent or -dependent) unlimited proliferation. Categorization of cell lines usually follows the physiological stages of hematopoietic differentiation in the various cell lineages. For an adequate classification, a detailed characterization of both primary and cultured cells in absolutely necessary. New cell lines, in particular, must be adequately, characterized; while cell culture data and immunological and cytogenetic features are essential, cell lines should be described in as much detail as possible. In addition to this recommended multiparameter characterization and the obligatory immortality of the culture, authentication of the true origin of the cells, novelty, scientific significance and availability of the cell line for other investigators are of utmost importance. It is still extremely difficult to establish new leukemia-lymphoma cell lines (except for some subtypes), and most attempts fail. Paramount to the lack of our understanding as to why certain cells start to proliferate in culture and others do not (thus implying a random process), is probably the difficulty of mimicking in vitro the physiological in vivo microenvironment. Attempts to improve the efficiency of cell line establishment should focus on examining the appropriateness of the in vitro culture conditions; these conditions should emulate as closely as possible the in vivo situation. In summary, leukemia-lymphoma cell lines have the potential to greatly facilitate diverse studies of normal and malignant hematopoiesis; to that end, these cell lines must be extensively characterized and adequately described.

Cell Line↗