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PubMed2006

Efficient fractionation and improved protein identification by peptide OFFGEL electrophoresis.

The sample fractionation steps conducted prior to mass detection are critically important for the comprehensive analysis of complex protein mixtures. This paper illustrates the effectiveness of OFFGEL electrophoresis with the Agilent 3100 OFFGEL Fractionator for the fractionation of peptides. An Escherichia coli tryptic digest was separated in 24 fractions, and peptides were identified by reversed-phase liquid chromatography on a microfluidic device with mass spectrometric detection. About 90% of the identified individual peptides were found in only one or two fractions. The distribution of the calculated isoelectric points for the peptides identified in each fraction was especially narrow in the acidic pH range. Standard deviations approached the size of the pH segment covered by the respective fraction. The experimental peptide isoelectric point measured by OFFGEL electrophoresis was used as an additional filter for validation of peptide identifications.

Chemical Fractionation↗
PubMed2001

Molecular phylogeny and taxonomic revision of Chlamydomonas (Chlorophyta). I. Emendation of Chlamydomonas Ehrenberg and Chloromonas Gobi, and description of Oogamochlamys gen. nov. and Lobochlamys gen. nov.

The genus Chlamydomonas (including Chloromonas) is one of the largest green algal genera comprising more than 600 species. To initiate a comprehensive analysis of the phylogeny and systematics of the genus, we determined nuclear-encoded SSU rRNA sequences from 32 strains of Chlamydomonas, Chloromonas and Chlorogonium with emphasis on oogamous taxa and related strains, and incorporated these into global molecular phylogenetic analyses of 132 strains of Chlorophyceae. In addition, we studied the morphology and reproduction of oogamous and related strains by light microscopy. We recognize and designate 18 monophyletic lineages (clades) within the Chlorophyceae, 11 of which are confined to the CW (basal bodies displaced clockwise) subgroup. The majority of clades recognized within the Chlorophyceae do not correspond to any of the traditional classification systems, which are still largely based on the organization level. Strains assigned to Chlamydomonas and Chloromonas were found in seven different clades confirming the polyphyly of the two genera as presently conceived. To initiate the taxonomic revision of Chlamydomonas, C. reinhardtii is proposed as the conserved type of the genus. In consequence, species in clades other than the clade containing C. reinhardtii must be transferred to other genera, a process initiated in this contribution. The oogamous strains studied represent a monophyletic lineage, which is described as Oogamochlamys gen. nov. comprising three species (O. gigantea, O. zimbabwiensis and O. ettlii spec. nov.). The sister clade to Oogamochlamys consists of isogamous strains characterized by chloroplasts with incisions and is described as Lobochlamys gen. nov. with two species (L. culleus and L. segnis). Another clade is characterized by asteroid or perforated, parietal chloroplasts and contains the type species of Chloromonas (C. reticulata). Thus, the polyphyletic Chloromonas (traditionally defined as "Chlamydomonas without pyrenoids") can be legitimized as a monophyletic genus by restriction to this clade and is here emended on the basis of chloroplast characters (the clade contains strains with or without pyrenoids thus rejecting the character "absence of pyrenoids").

Animals↗
PubMed1993

Spectacles improved to perfection and approved of by the Royal Society.

The letter sent by the Royal Society to the London optician, John Marshall, in 1694, commending his new method of grinding, has been reprinted, and referred to, in recent years. However, there has been no comprehensive analysis of the method itself, the letter and the circumstances in which it was written, nor the consequences for trade practices. The significance of the approval by the Royal Society of this innovation and the use of that approbation by John Marshall and other practitioners are examined. Gaps in existing accounts of Marshall's method are partly remedied by supplementing surviving written materials with accounts of contemporary, and present-day, trade practices based on his method. The reasons why Marshall and his contemporaries failed to record his method and specify his improvements are discussed. The reactions of the Spectacle Makers' Company and its more prominent members, both to the innovation itself and to the Royal Society's letter, are analysed. The impact of the new technique on contemporary and later opticians is described.

Eyeglasses↗
PubMed2001

Trends over time in the management of subarachnoid haemorrhage in newcastle: review of 1609 patients.

This article reviews trends in the management of subarachnoid haemorrhage (SAH) at the Regional Neurosurgery Unit in Newcastle over 9 years. This is a comprehensive analysis of prospectively collected data on patients with SAH. We review the changes in clinical therapy and outcome with regards to conservative (non-surgical), surgical and endovascular therapy. Since 1990, the demographic and management/outcome details of patients with SAH have been recorded systematically. This study involves patients admitted over the 9 years, from January 1990 to December 1998. The data were computerized using Microsoft Access (Microsoft Inc. USA), and analysed using SPSS statistical package. A total of 1609 had aneurysmal SAH confirmed with CT, lumbar puncture and/or angiography. Sixty-seven per cent (1,073 patients) were female with a female to male ratio of 2:1. This ratio was maintained from 1990 to date. The mean age has slowly increased from 49 years in 1990 to 55 years of age in 1998, (range 18-91). Overall, 53.9% (from 66.3% in 1990 to 35.3% in 1998) were surgically treated, 8.1% had embolization (range 0.6-18.4%) and 38% (range 28.2-46.4%) were managed without surgical intervention for the aneurysm. The proportion of patients undergoing surgery has decreased since 1994 with improvements in endovascular therapy, participation in the ISAT trial and increased admission of poor grade patients (WFNS grades 4 and 5, from 17% in 1990 to 31% in 1998). The mortality rate has doubled over the years under review (18-32%). The percentage of severely disabled patients has remained constant at about 7% with none in a vegetative state. Only 54% had a favourable outcome in 1998 compared with 78% in 1990. Total morbidity and mortality has increased particularly during the last 3 years. This has been associated with double the number of admissions in grade 5. Favourable outcome occurred in 90% of good grade patients (WFNS 1 and 2) with 6.2% mortality in surgical candidates and 5.5% in patients treated endovascularly. The mortality for poor grade (WFNS 4 and 5) patients was 64%.

Adolescent↗
PubMed2001

Outcome after mild-to-moderate blunt head injury: effects of focal lesions and diffuse axonal injury.

PRIMARY OBJECTIVE: A comparison of the effects of focal and diffuse axonal injury in mild-to-moderate traumatic brain injury (TBI). RESEARCH DESIGN: In a prospective longitudinal study of 138 consecutive patients suffering from TBI who were admitted to the Magdeburg University Hospital, 60 could be assessed neuropsychologically 8--31 days after trauma and 18--45 weeks later. METHODS AND PROCEDURES: GCS, CT-analysis, comprehensive neuropsychological assessment. MAIN RESULTS: The initial GCS-score was significantly correlated with outcome impairments of semantic fluency and memory in the Wechsler Similarities and in two clinical scales (Neurobehavioural Rating Scale, Frontal Lobe Score). The presence of CT-signs of DAI corresponded with deficits in tasks of response selection and suppression, the presence of focal contusions with results in the clinical scales, reaching significance for behavioural deficits with frontal contusions. Improvements between first and second assessments were pronounced in patients with signs of DAI. CONCLUSIONS: The data indicate that traumatic DAI results in mainly transient neuropsychological deficits. Focal frontal contusions result in more relevant deficits at outcome that affect behaviour and, thus, impair rehabilitation prognosis. It is concluded that even in clinically 'mild' TBI, prognosis and rehabilitation requirements should be established by early imaging and post-acute neuropsychological assessment.

Adolescent↗
PubMedDate not supplied

Introducing the pressure-sensing palatograph--the next frontier in electropalatography.

PRIMARY OBJECTIVE: To extend the capabilities of current electropalatography (EPG) systems by developing a pressure-sensing EPG system. An initial trial of a prototype pressure-sensing palate will be presented. RESEARCH DESIGN: The processes involved in designing the pressure sensors are outlined, with Hall effect transistors being selected. These units are compact, offer high sensitivity and are inexpensive. An initial prototype acrylic palate was constructed with five embedded pressure sensors. Syllable repetitions were recorded from one adult female. MAIN OUTCOMES, RESULTS AND FUTURE DIRECTIONS: The pressure-sensing palate was capable of recording dynamic tongue-to-palate pressures, with minimal to no interference to speech detected perceptually. With a restricted number of sensors, problems were encountered in optimally positioning the sensors to detect the consonant lingual pressures. Further developments are planned for various aspects of the pressure-sensing system. CONCLUSIONS: Although only in the prototype stage, the pressure-sensing palate represents the new generation of EPG. Comprehensive analysis of tongue-to-palate contacts, including pressure measures, is expected to enable more specific and effective therapeutic techniques to be developed for a variety of speech disorders.

Adult↗
PubMed1989

The effect of dietary interventions to reduce blood pressure in normal humans.

Changes in electrolyte intake have been advocated to lower the prevalence of hypertension in the normal population. To elucidate the potential impact of such strategies, we conducted a comprehensive analysis of data from three interventions, namely, salt (NaCl) restriction, calcium (Ca) supplementation, and potassium (K) supplementation in normal volunteers. Eighty-two adults lowered their Na intake from 157 +/- 6 S.E. to 68 +/- 3 mEq/day for 12 weeks. Population mean systolic and diastolic blood pressure decreased less than or equal to 2 mm Hg. Ca supplementation, 1.5 g daily for 12 weeks in 37 men, decreased blood pressure compared to 38 men receiving placebo. Ca supplementation, 1 g daily for 8 weeks in an older group of 44 normal subjects, decreased supine diastolic and standing systolic blood pressure. K supplementation with a nonchloride salt in 64 normal adults for 4 weeks had no effect on systolic or diastolic blood pressure even though urinary excretion was increased by 20 mmol/day. The responses to all interventions were Gaussian in distribution. A potentially adverse effect on blood pressure in some normal individuals cannot be excluded on the basis of the currently available data. Although all three interventions may benefit some hypertensive and some normal individuals, the data from these relatively short-term cross-sectional studies are insufficient to warrant generalized dietary recommendations for the normal population.

Adult↗
PubMed1985

A pH-dependent structural transition in the homopurine-homopyrimidine tract in superhelical DNA.

We have inserted the 509-bp-long fragment of sea urchin P. miliaris histone gene spacer region into plasmid pUC19. The fragment contains the 60-bp-long homopurine-homopyrimidine tract that is known to be hypersensitive to the S1 endonuclease. Using two-dimensional gel electrophoresis we have observed a sharp structural transition in the insert with increasing DNA superhelicity. As in the cases of cruciform and Z form formation, the observed transition partly relaxes the superhelical stress. In contrast with the other two well documented transitions, the observed transition strongly depends on pH. At pH7 and above the transition occurs at negative superhelicities exceeding the physiological range (- sigma greater than 0.08). For pH6 the transition occurs at -sigma = 0.055, whereas for pH4.3 it takes place at -sigma = 0.001. A comprehensive analysis of the obtained data has made it possible to define the nature of the observed transition. We conclude that under superhelical stress or/and at low pH homopurinehomopyrimidine tracts adopt a novel spatial structure called the H form.

Animals↗
PubMed2005

T cell abnormalities in systemic lupus erythematosus.

Because of the consensus that T cells play a central role in the pathogenesis of systemic lupus erythematosus (SLE), we explored the molecular basis of the defective function of SLE T cells for expression of signal transduction molecules, as well as surface structures such as adhesion molecules, by extensively testing peripheral blood T cells from SLE patients. Upregulated expression and function of adhesion molecules was observed in T cells from patients with active SLE who had specific clinical manifestations such as vasculitis, epithelitis and arthritis, but proximal signal transduction was defective. Comprehensive analysis to identify the molecules responsible for the defects showed the expression of the TCR zeta chain was attenuated, or absent in more than half of SLE patients. Moreover, the aberrant transcripts of the TCR zeta chain, including spliced variants lacking exon 7 and with a short 3' UTR, were detected in SLE T cells. Although attenuated expression of the TCR zeta chain is also observed in patients with cancers, infections and other autoimmune diseases, sustained attenuation of TCR zeta expression and aberrant transcripts are only observed in SLE. In this review we discuss the unique features of the TCR zeta defects in SLE.

Animals↗
PubMed1997

Resistance to heat radiosensitization and protein damage in thermotolerant and thermoresistant cells.

Recently, randomized phase III trials have indicated that hyperthermia combined with radiation leads to significantly better tumour control of certain malignancies than does radio-therapy alone. Yet, the full capacity of such combined treatments might not have been optimally exploited as in vitro data indicate that repeated beating of cells can result in either the development of a transient heat resistance (thermotolerance) and/or the selection/induction of a stable heat resistant cell population. Although the mechanism of thermotolerance and its effect on thermo-radiotherapy has been studied extensively, little data are available on the mechanism of stable heat resistance and its impact on combined heat and radiation treatments. In the current study, a comprehensive analysis was made of the differences and similarities between thermotolerance (TT) and stable heat resistance (TR) in terms of the mechanism of resistance to the direct toxic action of heat and in terms of the impact on the extent of thermal radiosensitization. Using heat resistant mutants previously derived from a murine radiation-induced fibrosarcoma (RIF-1), it was observed that these cells were resistant to protein denaturation and aggregation in the cytoplasmic/membrane compartment (measured by ESR (electron spin resonance) analysis and by in situ thermal denaturation of the foreign firefly luciferase targeted to the cytoplasm) but not in the nuclear compartment (measured by TX-100 insoluble nuclear proteins and by in situ thermal denaturation of luciferase targeted to the nucleus). RIF-1-TT cells, in contrast, were resistant for a 1 end-points tested. The lack of protection of nuclear heat damage in the RIF-TR cells could not be explained by a failure of one or more of the HSP70 isoforms to enter the nuclei of these cells. In relation to the absence or presence of heat resistance in the nucleus, the extent of heat radiosensitization was reduced in RIF-1-TT but not RIF-TR cells. This implies that resistance for heat killing is not necessarily accompanied by a reduction in the ability of heat to enhance the cellular radiosensitivity. The data indicate that the mechanism leading to permanent resistance after repeated heating and the mechanism causing thermotolerance may share common features but are in part different.

Animals↗
PubMed2002

Mutation of the ATM gene is not involved in the pathogenesis of either follicle center lymphoma or its transformation to higher-grade lymphoma.

Loss of function of the ataxia-telangiectasia mutated (ATM) gene, located on human chromosome 11q22-23, is the cause of ataxia-telangiectasia (A-T), which is associated with an extremely high risk for lymphoma. Abnormalities in 11q22-23, including deletions and mutations of the ATM gene, have been reported in T-cell prolymphocytic leukemias, B-CLL and in mantle cell lymphoma. In a survey of gene expression in follicle center lymphomas (FCL) and diffuse large B-cell lymphomas (DLBCL), almost all FCL expressed significant levels of ATM and the majority of DLBCL expressed low levels of ATM. This finding raised the possibility that the transformation of some FCL to DLBCL might be associated with inactivation of the ATM gene. Therefore, we analyzed biopsy specimens of 17 patients with FCL obtained at the time of diagnosis, four subsequent biopsies obtained at the time of FCL relapse and seven subsequent biopsies at the time of transformation to DLBCL. A comprehensive analysis of the ATM gene was performed by denaturing high performance liquid chromatography and sequencing. The analysis covered all of the 66 exons including the 9168 base pairs of ATM coding sequence as well as 16,676 base pairs of non-coding sequence. Twenty-eight known polymorphisms and rare sequence variants were observed, but no classic A-T mutations were detected. In 11 tumors, both tumor B-cells and normal T-cells were sorted for separate examination, and in each case, polymorphisms and rare variants were present in both tumor and normal cells. No new ATM gene mutations were associated with transformation from FCL to DLBCL. Thus, ATM gene mutations do not play a pivotal role either in the pathogenesis of FCL or in its transformation to DLBCL.

Ataxia Telangiectasia Mutated Proteins↗
PubMedDate not supplied

Risk characterization: principles and practice.

In the field of risk assessment, characterizing the nature and magnitude of human health or environmental risks is arguably the most important step in the analytical process. In this step, data on the dose-response relationship of an agent are integrated with estimates of the degree of exposure in a population to characterize the likelihood and severity of risk. Although the purpose of risk characterizations is to make sense of the available data and describe what they mean to a broad audience, this step is often given insufficient attention in health risk evaluations. Too often, characterizations fail to interpret or summarize risk information in a meaningful way, or they present single numerical estimates of risk without an adequate discussion of the uncertainties inherent in key exposure parameters or the dose-response assessment, model assumptions, or analytical limitations. Consequently, many users of risk information have misinterpreted the findings of a risk assessment or have false impressions about the degree of accuracy (or the confidence of the scientist) in reported risk estimates. In this article we collected and integrated the published literature on conducting and reporting risk characterizations to provide a broad, yet comprehensive, analysis of the risk characterization process as practiced in the United States and some other countries. Specifically, the following eight topics are addressed: (1) objective of risk characterization, (2) guidance documents on risk characterization, (3) key components of risk characterizations, (4) toxicity criteria for evaluating health risks, (5) descriptors used to characterize health risks, (6) methods for quantifying human health risks, (7) key uncertainties in risk characterizations, and (8) the risk decision-making process. A brief discussion is also provided on international aspects of risk characterization. A number of examples are presented that illustrate key concepts, and citations are provided for approximately 100 of the most relevant papers.

Animals↗
PubMed2006

Customer privacy on UK healthcare websites.

Privacy has been and continues to be one of the key challenges of an age devoted to the accumulation, processing, and mining of electronic information. In particular, privacy of healthcare-related information is seen as a key issue as health organizations move towards the electronic provision of services. The aim of the research detailed in this paper has been to analyse privacy policies on popular UK healthcare-related websites to determine the extent to which consumer privacy is protected. The author has combined approaches (such as approaches focused on usability, policy content, and policy quality) used in studies by other researchers on e-commerce and US healthcare websites to provide a comprehensive analysis of UK healthcare privacy policies. The author identifies a wide range of issues related to the protection of consumer privacy through his research analysis using quantitative results. The main outcomes from the author's research are that only 61% of healthcare-related websites in their sample group posted privacy policies. In addition, most of the posted privacy policies had poor readability standards and included a variety of privacy vulnerability statements. Overall, the author's findings represent significant current issues in relation to healthcare information protection on the Internet. The hope is that raising awareness of these results will drive forward changes in the industry, similar to those experienced with information quality.

Confidentiality↗
PubMedDate not supplied

Cytosolic phospholipase A2: biochemical properties and physiological roles.

Phosphatidylcholine (PC) is a major constituent of biological membranes and a component of serum lipoproteins and pulmonary surfactants. The PC and other glycerophospholipid compositions of membranes change dynamically through stimulus-dependent and independent pathways, principally by the action of two different types of enzymes; phospholipase A2 [EC 3.1.1.4] and acyl-CoA:lysophospholipid acyltransferase [EC 2.3.1.23]. Phospholipase A2 is a key enzyme that catalyzes deacylation of the sn-2 position of glycerophospholipids. This enzyme is critical in the remodeling of membrane lipids and formation of two subclasses of lipid mediators, fatty acid derivatives and lysophospholipids. Among many different subtypes of phospholipase A2 enzymes, we found that cytosolic phospholipase A2alpha (cPLA2alpha) is important in various pathological and physiological responses. Here, we summarize the phenotypes resulting from genetic ablation of cPLA2alpha, and the properties of newly discovered enzymes in the cPLA2 family. Comprehensive analysis of lipid mediators using liquid chromatography-tandem mass spectrometry (LC-MS/MS) is useful for understanding the roles of individual mediators in physiological and pathological processes.

Animals↗
PubMed1979

Influence of sonic noise on human stereoscopic depth perception.

Scientific establishment of the no-effect response to finite levels of exposure to a physical or chemical agent is indeed a rigorous exercise and is frequently controversial. In earlier research by Slutsky under direction of the senior author, a statistically significant increase in stereoscopic depth perception error was noted among 24 test subjects exposed to high intensity noise. Additional extensive research reported in this paper indicates that error in stereoscopic depth perception is not significantly altered by exposure to continuous white noise of short duration at levels ranging from 70 to 115 dBA. Furthernore, exposure of humans for periods of a few minutes to white noise in octave bands centered on 250 Hz, 1000 Hz, 4 kHz and 16 kHz at 115 dB does not affect their depth perception measured by the Howard-Dolman test. A comprehensive analysis of depth perception errors measured under noise exposure conditions (n = 4040) in comparison with those obtained under control conditions (n = 1430) produced a mean change in error of -0.38 mm, a statistically insignificant difference (p = 0.17). Even if such an error were attributable to high level noise, it should be noted that minus sign designates an improvement of depth perception in noise and that it is difficult to imagine visual tasks in which change in error of +/-0.38 mm at a distance of 6.0 meters is meaningful.

Depth Perception↗
PubMed1994

Expression and modulation of CD44 variant isoforms in humans.

CD44 is a ubiquitous surface molecule that exists as a number of isoforms, generated by alternative splicing of 10 "variant" exons. Little is known about the expression and function of the variant isoforms, except that certain isoforms may play a role in cancer metastasis. We produced mAbs against CD44 variant regions encoded by exons 4v, 6v, and 9v, by immunizing mice with a fusion protein spanning variant exons 3v to 10v. A comprehensive analysis of human tissues revealed that CD44 variant isoforms were expressed widely throughout the body, principally by epithelial cells. However there was differential expression of CD44 variant exons by different epithelia. Most epithelia expressed exon 9v, but much fewer expressed 6v or 4v. The regions of epithelia that expressed the highest levels of the variant isoforms were the generative cells, particularly the basal cells of stratified squamous epithelium, and of glandular epithelium. CD44 variant isoforms were also expressed differentially by leukocytes, with CD44-9v expressed at very low levels and CD44-6v and 4v virtually absent. However, CD44-9v and CD44-6v were the main variants that were transiently upregulated on T cells after mitogenic stimulation and on myelomonocytic cell lines by TNF alpha and IFN gamma treatment. Some epithelial cell lines could preferentially upregulate CD44-6v upon IFN gamma incubation. These results show that CD44 variant isoforms are expressed much more widely than first appreciated, and that expression of the variant isoforms on some cell types can be modulated by particular cytokines.

Amino Acid Sequence↗
PubMed1995

The ryanodine receptor/calcium channel genes are widely and differentially expressed in murine brain and peripheral tissues.

Ryanodine receptors (RyRs) are intracellular calcium release channels that participate in controlling cytosolic calcium levels. At variance with the probably ubiquitous inositol 1,4,5-trisphosphate-operated calcium channels (1,4,5-trisphosphate receptors), RyRs have been mainly regarded as the calcium release channels controlling skeletal and cardiac muscle contraction. Increasing evidence has recently suggested that RyRs may be more widely expressed, but this has never been extensively examined. Therefore, we cloned three cDNAs corresponding to murine RyR homologues to carry a comprehensive analysis of their expression in murine tissues. Here, we report that the three genes are expressed in almost all tissues analyzed, where tissue-specific patterns of expression were observed. In the uterus and vas deferens, expression of RyR3 was localized to the smooth muscle component of these organs. In the testis, expression of RyR1 and RyR3 was detected in germ cells. RyR mRNAs were also detected in in vitro-cultured cell lines. RyR1, RyR2, and RyR3 mRNA were detected in the cerebrum and in the cerebellum. In situ analysis revealed a cell type-specific pattern of expression in the different regions of the central nervous system. The differential expression of the three ryanodine receptor genes in the central nervous system was also confirmed using specific antibodies against the respective proteins. This widespread pattern of expression suggests that RyRs may participate in the regulation of intracellular calcium homeostasis in a range of cells wider than previously recognized.

Animals↗
PubMed1993

Induction of murine peritoneal gamma/delta T cells and their role in resistance to bacterial infection.

Previous studies have reported an association of gamma/delta T cells with microbial infection in both human lesions and murine infectious disease models. In this study we provide a comprehensive analysis of the conditions under which the induction of gamma/delta T cells occurs at a site of infection. We found a site-specific induction of gamma/delta T cells after the injection of Listeria monocytogenes in the peritoneal cavity of C3H mice. No changes were seen in the splenic or lymph node populations after these injections. Both the proportion and the absolute number of gamma/delta T cells increased in the peritoneal cavity. Additionally, when peritoneal T cells from Listeria-immune mice were restimulated in vitro, the induced gamma/delta T cells exhibited a greater expansion potential than the alpha/beta T cells. Neither the induced gamma/delta T cells nor those from normal mice expressed CD4 or CD8 on the cell surface. Thy-1 was expressed on only 29% of normal peritoneal gamma/delta T cells, but after intraperitoneal Listeria injection 65% of induced gamma/delta T cells expressed. Thy-1, Pgp-1 and CD45R expression on both normal and induced gamma/delta T cells was consistent with an activation phenotype. Significant increases in peritoneal gamma/delta T cells were not seen until 5-7 d after Listeria injection. The proportion of the CD3+ population expressing the gamma/delta T cell receptor remained elevated for 6-7 wk, while the absolute numbers of peritoneal gamma/delta T cells declined gradually over this time period, reflecting a decrease in both the number of lymphocytes and the percentage of these that were CD3+. Peak numbers of gamma/delta T cells were seen at day 10 with live microbes such as Listeria. A variety of microbes, toxins, mitogens, antigens, cytokines, and nonspecific inflammatory agents were evaluated for their ability to induce gamma/delta T cells in the peritoneal cavity. Both Gram-positive and Gram-negative bacteria as well as Mycobacteria were able to induce gamma/delta T cells that showed increased in vitro expansion potential. An exotoxin from a Gram-positive organism, listeriolysin-o, and the lipopolysaccharide (LPS) endotoxin from a Gram-negative organism were also effective. gamma/delta T cell responses to LPS were under lps gene control. Peak numbers of gamma/delta T cells were observed at day 3 after injection with exotoxins and endotoxins. Modifications that abrogated the virulence of a bacterial strain also eliminated the inductive effect for gamma/delta T cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗