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At least 991 records · Page 55Linked to original sources
PubMed1983

Interaction of antigen load and antibody response in determining heterologous protein nephritogenicity in inbred mice.

Genetically disparate inbred mouse strains mounting quantitatively different immune responses to a potentially nephritogenic heterologous protein had varied development of glomerulonephritis (GN) dependent upon the interaction between level of antibody response and antigen dose. High responder BALB/c mice given high doses of horse apoferritin developed a severe necrotizing GN. BALB/c mice given low dose horse apoferritin developed less severe GN, or when antibodies were in extreme excess, no GN. Low responder C3H mice given high dose horse apoferritin were in extreme antigen excess and developed no GN. C3H mice given low dose horse apoferritin developed a glomerulopathy characterized by capillary loop immune deposits. Interstrain differences in immune clearance and avidity did not account for this varied nephritogenicity, although avidity did relate to glomerular site of immune deposits in the BALB/c model. In the models under consideration susceptibility to heterologous antigen-induced glomerular injury was a function of the magnitudes of both the antibody response and the antigenic challenge.

Animals↗
PubMed2002

Complexities in ETS-domain transcription factor function and regulation: lessons from the TCF (ternary complex factor) subfamily. The Colworth Medal Lecture.

The ETS-domain transcription factor family can be divided into a series of subfamilies. Elk-1 represents the founding member of the ternary complex factor (TCF) subfamily. By focusing on the TCF subfamily, we can demonstrate the complexities that exist in the function and regulation of ETS-domain transcription factors. This article focuses on Elk-1 in detail and summarizes the functions of other TCFs. The key themes covered include the domain structure of the TCFs, the mechanisms of complex formation with serum response factor, regulation of TCFs by mitogen-activated protein kinase cascades, and transcriptional regulatory properties of the TCFs. Finally, the emerging role of the TCFs in vivo is discussed. A picture is developing indicating that, while these proteins exhibit significant sequence and functional conservation, key differences in their structure and regulation are being identified which may relate to unique functions of these proteins in vivo.

Amino Acid Sequence↗
PubMed2002

Genetic evidence of transmission of human T cell lymphotropic virus type 1 between spouses.

Sexual transmission of human T cell lymphotropic virus type 1 (HTLV-1) is considered to be an important route of infection in adults. However, no direct evidence has been reported that supports this observation. To address this issue, sequence variations of the gp46 (envelope)-coding region of HTLV-1 were determined in 13 patients infected with HTLV-1 who experienced seroconversion and in their spouses. Twenty-two nucleotide changes that were different from the reference sequence of lambdaATK-1 were identified. However, the gp46 sequences found were identical within each married couple. HTLV-1 proviral DNA loads measured in 11 of these couples varied from 10 to 3430 copies per 10(5) PBMC, and the proviral DNA loads of spouses often differed. This study provides the first genetic confirmation of the transmission of HTLV-1 from a carrier spouse to his/her partner. The findings also suggest that host-related factors play a more important role than do virus-specific factors in determining HTLV-1 proviral DNA load.

Base Sequence↗
PubMedDate not supplied

[A factor analysis of behavioral organization in mice].

Laboratory mice with Robertsonian translocation Rb(8,17)1Iem, mice of CBA substrain with the same translocation as well as CBA normal karyotype mice were investigated in several behavioural tests, their results being analysed by means of factor analysis. The genetic differences were revealed in the patterns of factor loadings, in particular in factors "feeding behaviour structure" and "weight loss". The behaviour of mice during logic problem solving (the ability to extrapolate the direction of food stimulus movement was tested) proved to be genotype-dependent in respect to connections with exploratory behaviour indices. Tendencies towards stereotypic or variable (plastic) behaviour patterns were revealed in CBA mice and mice with Rb(8,17)1Iem mice respectively.

Animals↗
PubMed2004

Neither the tumor necrosis factor alpha-308 A/G polymorphism nor the alpha2-macroglobulin polymorphism was associated with late-onset Alzheimer's disease in the Chinese population.

Late-onset Alzheimer's disease (LOAD) is the most common cause of dementia in the elderly. It is a complex and genetically heterogeneous disorder. Epidemiological studies demonstrated that nonsteroidal anti-inflammatory drugs could prevent or delay the onset of LOAD suggesting inflammation may be involved in AD. Tumor necrosis factor (TNF) is a potent immunomodulator and it might increase the production of amyloid beta(Abeta), which makes it an appropriate AD candidate gene. Alpha2 macroglobulin (A2M) is a serum protease inhibitor and a major low-density lipoprotein receptor-related protein (LRP) ligand. It can bind Abeta and mediate its clearance and degradation, suggesting it might be another AD candidate gene. In the present study, we analyzed the a 5 bp Ins/Del polymorphism of A2M gene (A2M-2), TNF alpha-308 A/G polymorphism and apolipoprotein E (APOE) polymorphisms of 67 sporadic late-onset AD patients and 142 normal elderly controls in the Chinese population. Our data showed that the APOE epsilon4 allele frequency in AD was significantly higher than that in the normal controls (chi2 = 11.66, P < 0.01) neither the frequencies of genotypes nor alleles of the TNF alpha-308 A/G and A2M polymorphisms were significantly different between AD and controls,suggesting the two polymorphisms were not risk factors to LOAD in Chinese.

Aged↗
PubMed1999

Tissue-specific changes of type 1 angiotensin II receptor and angiotensin-converting enzyme mRNA in angiotensinogen gene-knockout mice.

This study examined whether type 1 angiotensin II receptor (AT1) and angiotensin-converting enzyme (ACE) mRNAs are regulated during dietary salt loading in angiotensinogen gene-knockout (Atg-/-) mice which are genetically deficient in endogenous production of angiotensin II. Wild-type (Atg+/+) and Atg-/- mice were fed a normal-salt (0.3% NaCl) or a high-salt (4% NaCl) diet for 2 weeks. The mRNA levels were measured by Northern blot analysis. In Atg+/+ mice, concentrations of plasma angiotensin peptides were decreased by salt loading, whereas the treatment increased the brainstem, cardiac, pulmonary, renal cortex, gastric and intestinal AT1 mRNA levels. Salt loading also enhanced renal cortex ACE mRNA levels in Atg+/+ mice. Although plasma angiotensin peptides and urinary aldosterone excretion were not detected in Atg-/- mice, salt loading increased blood pressure in Atg-/- mice. In Atg-/- mice, pulmonary, renal cortex, gastric and intestinal AT1, and renal cortex and intestinal ACE mRNA levels were higher than those in Atg+/+ mice. However, salt loading upregulated AT1 mRNA expression only in the liver of Atg-/- mice, and the treatment did not affect ACE mRNA levels in Atg-/- mice. Furthermore, although the levels of ACE enzymatic activity showed the same trend with the ACE mRNA levels in the lung, renal cortex and intestine of both Atg-/- and Atg+/+ mice, the results of radioligand binding assay showed that cardiac expression of AT1 protein was regulated differently from AT1 mRNA expression both in Atg-/- and Atg+/+ mice. Thus, expression of AT1 and ACE is regulated by salt loading in a tissue-specific manner that appears to be mediated, at least partly, by a mechanism other than changes in the circulating or tissue levels of angiotensin peptides.

Angiotensin II↗
PubMed1998

Analysis of HTLV-I proviral load in 202 HAM/TSP patients and 243 asymptomatic HTLV-I carriers: high proviral load strongly predisposes to HAM/TSP.

In order to examine the effect of HTLV-I proviral load on the pathogenesis of HAM/TSP, we measured the HTLV-I proviral load in peripheral blood mononuclear cells (PBMC) from a large number of HAM/TSP patients and asymptomatic HTLV-I carriers. To measure the proviral load, we used an accurate and reproducible quantitative PCR method using a dual-labeled fluorogenic probe (ABI PRISM 7700 Sequence Detection System). The mean +/- standard error of mean (s.e.m.) HTLV-I proviral copy number per 1 x 10(4) PBMC was 798 +/- 51 (median 544) in 202 HAM/TSP patients; 120 +/- 17 (median 34) in 200 non HAM-related (general) asymptomatic HTLV-I carriers (RC); and 496 +/- 82 (median 321) in 43 asymptomatic HTLV-I carriers genetically related to HAM/TSP patients (FA). The prevalence of HAM/TSP rises exponentially with log (proviral load) once the proviral load exceeds 1% PBMC. The HTLV-I proviral load of female patients with HAM/TSP was significantly higher than that of male patients, however there was no significant difference in proviral load between sexes in RC. There was a significant correlation between the proviral load and the concentration of neopterin in CSF of HAM/TSP patients. These results indicate that the HTLV-I proviral load in PBMC may be related to the inflammatory process in the spinal cord lesion. The increased proviral load in FA suggests the existence of genetic factors contributing to the replication of HTLV-I in vivo.

Adult↗
PubMed2000

Gene transfer of anti-gp41 antibody and CD4 immunoadhesin strongly reduces the HIV-1 load in humanized severe combined immunodeficient mice.

OBJECTIVE: To study the anti-HIV-1 effects of the delivery of anti-gp41 monoclonal antibody (mAb) and soluble CD4 (sCD4) immunoadhesin by genetically modified cells in HIV-1-infected, humanized severe combined immunodeficient (SCID) mice. DESIGN: The complementary DNA of mAb 2F5, an anti-HIV-1 gp41 antibody, and of sCD4-IgG chimeric immunoadhesin were transferred into 3T3 cells using Moloney murine leukaemia virus vectors. The cells were then incorporated into a collagen structure called the neo-organ, which allowed the continuous production of the therapeutic molecules. METHODS: The antiviral effects in vivo of 2F5 or sCD4-IgG or both compounds were evaluated in neo-organ-implanted SCID mice that were grafted with human CD4 CEM T cells and challenged with HIV-1 Lai or MN. RESULTS: In SCID mice implanted with 2F5 neo-organs, antibody plasma levels reached 500-2000 ng/ml. Viral loads after HIV-1 challenge were significantly reduced in neo-organ-implanted HIV-infected mice. Although 29 x 10(7) and 13 x 10(8) HIV-1-RNA copies/ml were detected at 12 days in the controls (mice injected with Lai and MN, respectively) less than 16.5 x 10(3) HIV-1-RNA copies/ml were observed in all implanted mice injected with either Lai or MN. The intracellular viral load was also reduced in CD4 cells recovered from the implanted mice. Comparable antiviral effects were obtained with CD4-IgG neo-organs. CONCLUSION: Our results confirm the anti-HIV properties of 2F5 and sCD4-IgG continuously produced in vivo after ex-vivo gene therapy in SCID mice.

3T3 Cells↗
PubMed2000

Heritability of central systolic pressure augmentation: a twin study.

Less than 50% of the variance in left ventricular mass is explained by conventional factors such as age, blood pressure, and body size. Genetic influences may account for part of the unexplained variance. The central (aortic) pressure augmentation index has been suggested as a noninvasive measure of pulsatile load, which is a likely determinant of left ventricular mass. We quantified the genetic influence on augmentation index and determined the extent to which this influence is dependent on the effects of age, height, heart rate, and blood pressure. We performed a classical twin study composed of 225 monozygotic and 594 dizygotic female white twin pairs aged 18 to 73 years. Augmentation index and mean arterial pressure were based on the central pressure wave derived from the radial waveform as measured by applanation tonometry. Quantitative genetic modeling techniques were used to analyze the data. The heritability of augmentation index was 37%, whereas heritabilities for blood pressure traits varied between 13% and 25%. Most of the variance in augmentation index could be explained by genetic and environmental factors specifically influencing augmentation index. Only a relatively small part of the total variance in augmentation index could be attributed to genes in common with height (3.1%), heart rate (4.6%), and mean arterial pressure (5.6%). Age explained 19% of the total variation in augmentation index. In conclusion, augmentation index has a significant heritable component, which is largely independent of the influence of blood pressure, heart rate, height, and age. Finding genes for the augmentation index could help to unravel pathophysiological mechanisms causing left ventricular hypertrophy and lead to improvements in prevention, diagnosis, and treatment of at-risk populations.

Adolescent↗
PubMed2004

Association of the HTR6 polymorphism C267T with late-onset Alzheimer's disease in Chinese.

Serotonergic neurotransmitter system has been implicated in the pathogenesis of Alzheimer's disease (AD). 5-Hydroxytryptamine (5-HT)(6) receptor is mainly expressed in the brain areas involved in cognitive processes. And 5-HT(6) receptor gene (HTR6) variants may be a genetic risk factor for late-onset Alzheimer's disease (LOAD). To assess whether HTR6 increases the risk for LOAD, we carried out an association study between the HTR6 polymorphism C267T and sporadic LOAD in Mainland Chinese. An association of C/T genotype with LOAD (OR = 2.10, P = 0.014) was observed. And no statistical difference was found between cases and controls after stratification for APOE epsilon4 status. These data suggest that the HTR6 polymorphism C267T possibly involved in the susceptibility to LOAD as an APOE epsilon4-allele independent risk factor of LOAD.

Aged↗
PubMed1995

[Intraspecific genetic diversity: monitoring and principles of conservation].

Genetic differentiation of a species, estimated on average according to the aggregate of allozyme loci, corresponds to a selectively neutral process. Such evolution is traditionally regarded as Markov's chain, in which the genetic dynamics of a population cannot be predicted for more than one generation. According to the concept of population systems, however, intraspecific differentiation can be interpreted as a process with memory, which retains information about the genetic structure of the ancestral population. This memory is maintained due to the organizing effect of gene immigration whose intensity is the higher, the lower the effective size of the local population. The ratio between intra- and inter-population components of gene diversity is maintained at a stable (optimal) level. Consequently, it can be regarded as the basic "reference point" in genetic monitoring of subdivided populations that have evolved under anthropogenic pressure. Such influences, altering established systemic links, distort the balance between differentiation and integration of the species gene pool and lead to adverse effects. Depending on the predominance of the inter- or intra-population component of gene diversity, these influences may be equivalent to outbreeding with an increased segregational load or to inbreeding, respectively. In the first case, the genetic process is adaptive, and, provided the negative influence is terminated in due time, it is possible to restore the genetic structure and normalize reproduction of gene pools in populations. In the second case, the genetic process is maladaptive and leads to degradation of populations. If one knows principles of the systemic organization of a species, it is possible to develop an approach to solving the problem of conservation of biological diversity by organizing non-exhaustive wildlife management.

Adaptation, Biological↗
PubMed1998

Pharmacology of the cardiac sarcoplasmic reticulum calcium ATPase-phospholamban interaction.

Accumulating evidence points to the critical role of phospholamban (PLB) regulation of the cardiac sarcoplasmic reticulum (SR) calcium ATPase in influencing the kinetics of calcium handling within the cardiac myocyte under normal and pathological conditions. Based on the data, it has been hypothesized that PLB inhibitors (e.g., calcium ATPase stimulators) would be of potential importance as positive lusitropes and inotropes in the treatment of heart failure. Experiments measuring tension transients in saponin-permeabilized cardiac muscles from genetically engineered mice under a variety of SR calcium loading conditions provide evidence of the functional alterations that can be achieved by manipulation of the degree of PLB inhibition of the calcium pump. Testing of the above hypothesis will ultimately require a selective, high-affinity, membrane-permeable small molecule stimulator of the cardiac calcium pump. Screening for cardiac calcium pump activators has produced a series of agents exerting apparently different mechanisms of action; some may be tools to help to elucidate the nature of the PLB-calcium ATPase interaction(s). The rationale for PLB as a drug target, the optimal profile of a PLB inhibitor, and the properties of several low-molecular-weight compounds will be explored.

Animals↗
PubMed2004

Generation of tumor-specific cytotoxic T lymphocyte and prolongation of the survival of tumor-bearing mice using interleukin-18-secreting fibroblasts loaded with an epitope peptide.

There is currently much interest in generating cytotoxic T lymphocyte (CTL) responses against tumor antigens as a therapy for cancer. In this study mouse fibroblasts (H-2(b)) were genetically modified to express a costimulatory B7.1 and a mature interleukin (IL)-18, and then loaded with an ovalbumin (OVA) epitope (SIINFEKL, H-2K(b) restricted) as a model antigen, and tested for the induction of OVA-specific CTLs in C57BL/6 mice (H-2(b)). The genetically modified fibroblasts lacking either IL-18 or B7.1 were also constructed. Immunization with the IL-18/B7.1-transfected fibroblasts induced strong cytotoxic activities against OVA-expressing EL4 (EG7) tumor cells, but not against other H-2(b) tumor cells such as EL4, C1498, and B16F1 cells. The magnitude of the cytotoxic response in mice with the IL-18/B7.1-transfected fibroblasts was significantly higher than the response in mice immunized with any other cell constructs. CD8(+) T cells with OVA-specific cytotoxic activities were predominant in mice immunized with the IL-18/B7.1-transfected fibroblasts. Furthermore, treatment with the IL-18/B7.1-transfected fibroblasts significantly prolonged the survival period of EG7 tumor-bearing mice. Anti-tumor CTL immunity by the IL-18/B7.1-transfected fibroblasts could be induced without the help of host antigen-presenting cells (APCs) and NK1.1(+) cells, whereas partially decreased by the depletion of CD4(+) T cells at the inductive stage. These results support the ability of IL-18/B7.1 gene transfer to enhance the antigen-presenting capacity of fibroblasts for inducing antigen-specific CTL response.

Animals↗
PubMed2000

The genetic structure of the Raleigh natural population of Drosophila melanogaster revisited.

The Raleigh natural population of Drosophila melanogaster was reanalyzed with special attention to possible dysgenic effects during the extraction of chromosomes. About 600 second chromosomes were extracted from the Raleigh natural population, half in the cytoplasm of wild-caught females (native genetic background) and half in the cytoplasm of the laboratory line, C160(In(2LR)SM1, Cy/In(2LR)bw(V1)) (foreign genetic background). We could not find significant differences between the two extraction schemes in the frequency of lethal second chromosomes (Q = 0.252 for the lines with the negative genetic background vs. 0.231 for the lines with the foreign genetic background) or in the homozygous detrimental (D) and lethal (L) loads (D = 0.210 vs. 0.251; L = 0.287 vs. 0.264). The effective size of the population was estimated to be approximately 19,000, based on the allelism rate of lethal-bearing chromosomes. The homozygous load markedly decreased in the 15 years since a previous study of the same population.

Animals↗
PubMed1985

Na+-K+ cotransport and hypertension. Effect of piretanide and hydrochlorothiazide on red blood cell sodium concentration in acutely salt-loaded hypertensive and normotensive rats.

Na+-K+ cotransport has been presumed to be a genetic marker or aetiological factor in essential hypertension in numerous studies. In spite of extended in vitro research, the role of this transport system in hypertension could not be proved. In the present study the action of the cotransport inhibitor piretanide and the non-loop diuretic hydrochlorothiazide (HCT) on red blood cell (RBC) sodium concentration was examined under in vivo conditions in spontaneously hypertensive rats (SHR) and normotensive Sprague Dawley rats (NSDR) during acute salt-loading. Before drug administration salt-loading resulted in an increase of RBC sodium concentration, the percentage of which was not different in SHR and NSDR. However, after administration of piretanide in oral doses of 8-32 mg/kg body weight, the percent increase in RBC sodium was lower in SHR than in NSDR. This effect which was found to be dose-dependent was not brought about by HCT. The data might be due to a piretanide inhibition of sodium-induced inward RBC Na+-K+ cotransport more pronounced in SHR than in NSDR.

Animals↗
PubMed1992

Relevance of early age-of-onset in genetic studies of bipolar affective disorder.

Early age-of-onset appears to predict higher familial loading in bipolar affective disorder. This finding, coupled with ongoing attention to the importance of genomic heterogeneity for segregation and linkage analyses, underscores the value of research on juvenile samples. This research is reviewed, and implications for future research on genetic classification of bipolar illness are noted.

Bipolar Disorder↗
PubMed2000

Vaccination against Taenia solium cysticercosis in underfed rustic pigs of México: roles of age, genetic background and antibody response.

Vaccination of pigs of mixed genetic make-up, raised as rustically as done in rural Mexico, resulted in effective protection to experimental challenge against Taenia solium cysticercosis. Maximum protection was achieved if pigs were immunized at 70 days of age. There was large variation of viable parasite load within vaccinated pigs and controls, which is suggestive of significant genetic factors influencing susceptibility, besides immunization. Our results strengthen the advisability of pig vaccination for control of T. solium cysticercosis, since it lowers the number of viable cysticerci capable of transforming into tapeworms.

Age Factors↗
PubMed2002

Strategies for early diagnosis of haemochromatosis.

Genetic haemochromatosis is one of the most frequent inborn errors of metabolism. Only patients with early non-cirrhotic haemochromatosis treated by phlebotomies have a normal life expectancy. The present review analyses strategies for early diagnosis of haemochromatosis by using the Medline database and own data from a large cohort of patients with haemochromatosis. The still widely used approach to look for haemochromatosis in the presence of clinical complications such as liver disease will detect haemochromatosis in a considerable percentage of patients with Celtic origin. However, up to one half of these patients will already have an irreversible complication such as liver cirrhosis, diabetes mellitus or cardiomyopathy. In contrast, screening approaches of non-selected asymptomatic subjects using either determination of transferrin saturation and serum ferritin (phenotypic screening) or using genetic testing will detect haemochromatosis in most subjects in a precirrhotic stage without irreversible complications. Both phenotypic and genetic screening are highly cost-effective for detection of iron-loaded individuals in the general population. The current clinical approach to look for haemochromatosis in the presence of clinical disease is unacceptable. Only a more general type of screening in asymptomatic subjects including genetic testing will increase the rate of early diagnosis and will further improve the clinical outcome.

Genetic Testing↗