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PubMed2002

Sociodemographic context of the AIDS epidemic in a rural area in Tanzania with a focus on people's mobility and marriage.

This analysis focuses on how sociocultural and economic characteristics of a poor semi-urban and rural population (Kisesa ward) in north west Tanzania may directly and indirectly affect the epidemiology of HIV and other sexually transmitted infections (STI). Poverty and sociocultural changes may contribute to the observed high levels of marital instability and high levels of short and long term migration in Kisesa, especially among younger adults. Marriage and migration patterns are important underlying factors affecting the spread of HIV. The most cost-effective intervention strategy may be to focus on the trading centre in which mobility is higher, bars were more common, and HIV prevalence and incidence were considerably higher than in the nearby rural villages. If resources suffice, additional work can be undertaken in the rural villages, although it is not clear to what extent the rural epidemic would be self sustaining if the interventions in the trading centre were effective.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Tick-borne Kemerovo group orbiviruses in a Newfoundland seabird colony.

Five new isolates of Kemerovo group viruses were recovered from Ixodes uriae collected on Great Island, Witless Bay Seabird Sanctuary, Newfoundland, Canada, during July 1985. This brings the total number of Orbivirus isolates on Great Island to 18 isolates including the 7 from 1971 and 6 from 1972. Genomic segments of several strains were compared by polyacrylamide gel electrophoresis. The degree of variation in each segment of these viruses was calculated. Great Island and Bauline viruses exhibited a great degree of variation in dsRNA migration patterns. Great Island and Bauline genomes averaged 11.60 (SD = 0.107) and 11.69 megadaltons (SD = 0.075), respectively. Variation was observed in all 10 segments of Great Island and Bauline viruses. These findings were compared with serologic and protein gel data.

Animals↗
PubMed1992

Rotavirus electropherotypes in Malaysian children.

A 12-month study was carried out on the molecular epidemiology of rotavirus in urban and suburban Malaysian children. Analysis of faecal samples from 973 hospitalized diarrhoeic children by polyacrylamide gel electrophoresis detected 268 rotaviruses (28%). All isolates were group A rotaviruses, which produced 22 electropherotypes: 16 (91.5%) with long RNA migration patterns and 6 (8.5%) with short patterns. One of the long-pattern electropherotypes was the predominant strain (71.1% of the total electropherotypes) isolated during this study. Although 3 other strains were detected sporadically over the study period, 16 others were present only during the first 7 months and 2 others were confined to the last 5 months. Long- and short-pattern electropherotypes were found to co-circulate extensively. There was a significant association of short-pattern electropherotypes with infection in older children. In addition, the prevalence of vomiting and mean duration of diarrhoea were significantly associated with different electropherotypes.

Child↗
PubMed1979

Human lymphocyte migration in vitro: characterization and quantitation of locomotory parameters.

Using a time-lapse cinephotomicrographic technique, the locomotory paths taken by lymphocytes have been shown to satisfy the requirements for a continuous-time Markov chain analysis consisting of four directional states defined by the four quadrants of a Cartesian plane and state 0 in which the cells are stationary. The important parameters characterizing this path motion are the average time (waiting time) that a cell spends in each state and the state transition probabilites which, using the Markov model, allow the computation of the probability of the cells moving in a given direction. Our results show that lymphocytes moving alone on glass exhibit a random migration pattern.

Cell Movement↗
PubMed1999

Altered migration of gut-derived T lymphocytes after activation with concanavalin A.

Although activation of lymphocytes is known to be associated with profound changes in homing behavior, it remains unclear how activation alters migration of gut-derived lymphocytes in lymphoid and nonlymphoid organs. The objectives of this study were 1) to compare migration of naive and concanavalin A (ConA)-activated T lymphocytes into the gut mucosa, spleen, and liver and 2) to define the role of specific adhesion molecules in this homing process. Fluorescently labeled T lymphocytes collected from rat intestinal lymph were injected into the jugular vein, and the kinetics of appearance of the infused lymphocytes were monitored in ileal Peyer's patches, spleen, and liver. The migration of naive and ConA-activated T lymphocytes into microvessels were compared using an intravital microscope. ConA stimulation significantly increased the rolling velocity of T lymphocytes in postcapillary venules of Peyer's patches, and ConA-stimulated lymphocytes exhibited a loss of the selective adherence properties in Peyer's patches that is normally observed with naive T cells. ConA activation also suppressed the accumulation of T cells in the spleen. On the other hand, the adherence of T cells to hepatic sinusoidal endothelium was significantly increased after ConA activation, especially in the periportal area, and this increase was attenuated by an anti-intercellular adhesion molecule (ICAM)-1 antibody. Flow cytometry analysis revealed a decline in L-selectin expression and an increase in CD11a expression and ICAM-1 on the surface of ConA-treated T cells. In conclusion, activation of gut-derived T lymphocytes with ConA significantly alters their migration path, with a diminished localization to Peyer's patches and spleen and a preferential accumulation in hepatic sinusoids. This altered migration pattern likely results from changes in the expression of leukocyte adhesion molecules such as L-selectin and CD11a.

Animals↗
PubMed1997

Purification, characterization, and localization of two ATP diphosphohydrolase isoforms in bovine heart.

Two ATP diphosphohydrolase (ATPDase) isoforms have been purified from the bovine heart ventricle. The purification procedure includes the following steps: differential centrifugation, sucrose cushion centrifugation, solubilization with Triton X-100, DEAE agarose ion exchange, and Affi-Gel blue-Sepharose and concanavalin A (con A)-Sepharose chromatographies. The purified enzyme has an optimum pH of catalysis of 7.5 and requires Ca2+ or Mg2+. The apparent Michaelis constant of the enzyme, with ADP as the substrate, is 29 microM, and the apparent maximal velocity is 1.6 mumol.min-1.mg protein-1. Substrate specificity, heat-inactivation curves, and copurification of adenosinetriphosphatase (ATPase) and adenosinediphosphatase (ADPase) activities confirmed the identity of the purified enzyme as an ATPDase. In addition, polyacrylamide gel electrophoresis, under nondenaturing conditions, showed identical migration patterns for the protein involved in ATPase and ADPase activities. Western blot analysis, with an antibody that specifically recognizes the NH2-terminal sequence of pig pancreas ATPDase and specifically reacts with bovine and human ATPDases, showed cross-reactivity with the purified ATPDase isoforms from the bovine heart. Immunocytochemical localization in the ventricle produced strong reactions with the plasma membrane of Purkinje fiber cells and the majority of myocardial cells. Immunoreactivity was variable, producing a mosaic-like aspect. As expected, smooth muscle cells and endothelial cells of coronary vessels were highly reactive. This ectoenzyme could play a protective role against the potentially deleterious effects of extracellular ATP. In tandem with 5'-nucleotidase, it produces adenosine, a powerful vasodilator, especially in hypoxic or ischemic conditions that favor the release of ATP.

Animals↗
PubMed2005

In vitro and in vivo regulation of transepithelial lung alveolar sodium transport by serine proteases.

The amiloride-sensitive epithelial sodium channel (ENaC) constitutes a rate-limiting step for sodium (Na+) and water absorption across lung alveolar epithelium. Recent reports suggested that ENaC is regulated by membrane-bound extracellular serine proteases, such as channel-activating proteases (CAPs). The objectives of this study were to examine the role of serine proteases in the regulation of transepithelial alveolar Na+ and water transport in vitro and in vivo and the expression of CAPs in rodent distal lung. In vitro experiments showed that inhibition of endogenous serine proteases by apical aprotinin 1) decreased ENaC-mediated currents in primary cultures of rat and mouse alveolar epithelial cells without affecting the abundance nor the electrophoretic migration pattern of biotinylated alpha- and beta-ENaC expressed at the cell surface and 2) suppressed the increase in amiloride-sensitive short-circuit current induced by the beta2-agonist terbutaline. RT-PCR experiments indicated that CAP1, CAP2, and CAP3 mRNAs were expressed in mouse alveolar epithelial cells, whereas CAP1 was also expressed in alveolar macrophages recovered by bronchoalveolar lavage. CAP1 protein was detected by Western blotting in rat and mouse alveolar epithelial cells, alveolar macrophages and bronchoalveolar lavage fluid. Finally, in vivo experiments revealed that intra-alveolar treatment with aprotinin abolished the increase in Na+-driven alveolar fluid clearance (AFC) induced by terbutaline in an in situ mouse lung model, whereas trypsin potentiated it. These results show that endogenous membrane-bound and/or secreted serine proteases such as CAPs regulate alveolar Na+ and fluid transport in vitro and in vivo in rodent lung.

Adrenergic beta-Agonists↗
PubMed1991

Abnormal proximal tubule apical membrane protein composition in X-linked hypophosphatemic mice.

The hypophosphatemic (Hyp) mouse is characterized by an isolated X-linked defect in proximal tubular phosphate (Pi) reabsorption associated with a decreased maximum velocity (Vmax) and a normal affinity (Km). To directly investigate the underlying cellular defect proximal tubular brush-border membranes (BBM) from normal control (Con) and Hyp male littermates were examined for differences in cholesterol content, total and individual phospholipid composition, phospholipid incorporation rates, membrane fluidity, and by two-dimensional sodium dodecyl sulfate (SDS)-polyacrylamide protein electrophoresis. The cholesterol content, total and individual phospholipid profiles, phospholipid incorporation rates, and membrane fluidity of Con and Hyp BBM samples were comparable. However, the two-dimensional gel electrophoreses of Con and Hyp BBM proteins, run simultaneously under identical conditions, revealed a protein with an apparent abnormal isoelectric migration pattern in Hyp BBM samples. This protein had an apparent molecular weight 56,000 and an apparent pI of 7.2 and was consistently evident on Hyp gels (n = 3) but not on Con gels (n = 3). The appearance of this protein band was associated with a diminution in staining of a control protein of comparable apparent molecular weight but markedly lower apparent pI.

Animals↗
PubMed2001

Consanguinity in South America: demographic aspects.

A sample of 53,552 nonmalformed liveborn infants was ascertained by the Latin-American Collaborative Study of Congenital Malformations between 1967 and 1996. The mean consanguinity rate was 0.96%, with significantly higher values in Brazil and Venezuela, and lower in Argentina. Low paternal education and occupation levels were positively associated with consanguinity. First-cousin matings represented almost half of all consanguineous couples. The consanguinity was mainly of more closely related types in Brazil, while in Venezuela more remote types predominated. This could reflect differences in migration patterns and rates between these two countries.

Consanguinity↗
PubMed1999

A novel frameshift mutation in the first exon of the 21-OH gene found in homozygosity in an apparently nonconsanguineous family.

Congenital adrenal hyperplasia is most frequently due to steroid 21-hydroxylase (21-OH) deficiency. Due to the existence of a pseudogene in tandem duplicated with the 21-OH gene, asymmetric recombination causes the majority of the molecular defects underlying this deficiency: gene conversions and deletions of the functional gene. Screening for a small array of mutations, those existing in the pseudogene together with deletions, allows the characterization of most mutated alleles, 91% in the Spanish population. We report the case of a boy from a nonconsanguineous family, diagnosed during the neonatal period of a salt-wasting form of the deficiency, in which this screening did not allow the characterization of the paternal or the maternal allele. This infrequent finding in a nonconsanguineous family was further investigated. Single-strand conformation polymorphism screening for new mutations revealed an abnormally migrating pattern when polymerase chain reaction fragments from 21-OH gene exon 1 of the patient and relatives were analyzed. Upon direct sequencing, the insertion of a T at position 64 (64insT, frameshift generating a stop codon at exon 2) was found in homozygosity in the patient. Microsatellite typing in the HLA region revealed the patient to be homozygous for five markers (heterozygosities 0.62 to 0.74). Apparently this new mutation was generated several generations ago and has been preserved for years. Consanguinity had been discarded for several generations, although both families could be traced back to a small rural area in Navarra (Spain).

Amino Acid Sequence↗
PubMed1999

Molecular analysis of the carboxy terminus of the beta and gamma subunits of the epithelial sodium channel in patients with end-stage renal disease.

BACKGROUND: Mutations in the carboxy termini of the beta subunit (hbetaENaC) and the gamma subunit (hgammaENaC) of the human epithelial sodium channel have been identified in patients with Liddle syndrome. Moreover polymorphisms have been described in these genes, the clinical relevance of which for progression to end-stage renal disease (ESRD) is unknown. We, therefore, have screened ESRD patients for putative variants of these genes. METHODS: We investigated 256 chronic hemodialysis patients, including 123 patients with a history of hypertension as a cause of ESRD. Screening for mutations in the carboxy termini of hbetaENaC and hgammaENaC was accomplished by polymerase chain reaction amplification followed by single-strand conformation polymorphism analysis. RESULTS: In 231 patients single-strand conformation polymorphism analysis of the polymerase chain reaction fragments of the hbetaENaC and hgammaENaC genes showed a similar migration pattern as compared with negative control subjects. In 25 patients a band shift was observed. However, sequence analysis in all these patients revealed wild-type sequence. CONCLUSIONS: The present study demonstrates the absence of genetic variants in the carboxy terminus of the hbetaENaC and hgammaENaC genes in Austrian patients with ESRD maintained on chronic hemodialysis treatment. Thus, mutations in these genes are unlikely to be associated with ESRD.

DNA Primers↗
PubMed2002

Castes, migration, immunogenetics and infectious diseases in south India.

It has been said that the grandest genetic experiment of nature has been conducted in south India in the name of the caste system. One can expect the frequency of an infectious disease to be equal to the product of the frequencies of various indicated loci/alleles, whether physiological, hormonal or immunological, in an endemic area. The sympatrically isolated caste and sub-caste populations of southern India, with differing origins, migration patterns and breeding habits, differ significantly in their HLA and other immune repertoire and are ideal models to study and test this hypothesis. The prevalence of a number of major infectious diseases, including TB and leprosy, are reviewed in different communities in the light of their genetic history.

Journal Article↗
PubMedDate not supplied

Preferential migration of CD62L cells into the appendix in mice with experimental chronic colitis.

BACKGROUND: Clinical and experimental studies suggest that appendectomy can protect against development of ulcerative colitis and Crohn's disease. However, how T cells in the appendix affect the development of colitis has not been clarified. AIM: To investigate the in vivo migration and activation of colitis-inducing CD62L+ cells during development of chronic colitis. METHODS: CD62L+CD4+ cells were fluorescently labeled and transferred to severe combined immunodeficient (SCID) mice to induce colitis. In vivo migration of T cells into the mucosa of the appendix and colon was quantified by in vivo microscopy after 7 weeks. In a second experiment, unlabeled CD62L+CD4+ cells were transferred, reisolated after 7 weeks, and adhesion molecule (integrin alpha4beta7) and costimulatory molecule (CD154) expression was analyzed. RESULTS: Six to eight weeks after CD62L+CD4+ cell transfer, SCID mice developed chronic colitis. In vivo microscopic analysis demonstrated a preferential migration of fluorescence-labeled CD62L+CD4+ cells into the mucosa of the appendix versus the colon. Re-isolation of lamina propria cells from mice with colitis confirmed that CD62L+CD4+ cell migration was significantly enhanced in the appendix, compared to the colon (3.5-fold). Furthermore, a higher proportion of CD62L+CD4+ cells re-isolated from the appendix expressed integrin alpha4beta7 and CD154 than from the colon. CONCLUSION: This study demonstrates the preferential migration of CD62L+CD4+ cells into the appendix as compared to the colon. This migration pattern correlated with upregulation of integrin alpha4beta7 and CD154 (CD40 ligand) on T cells. Our results suggest an important role of the appendix in the pathogenesis of colitis.

Adoptive Transfer↗
PubMed1994

Expression of immunoreactive polysialylated neural cell adhesion molecule in the suprachiasmatic nucleus.

Light-microscopic and immunoblot immunochemical procedures were used to study the distribution and biochemical characteristics of neural cell adhesion molecule (NCAM) and its polysialylated form (PSA-NCAM) in the suprachiasmatic nuclei (SCN) of the adult Siberian hamster. In the adult brain PSA-NCAM is located in regions capable of undergoing morphological rearrangements and thus is generally considered to be an indicator of neural plasticity. Immunostaining for PSA in the Siberian hamster SCN (using a monoclonal antibody against the alpha 2,8-linked PSA of NCAM) was evident throughout the rostrocaudal axis of the SCN, with the most intense reaction in the ventrolateral region. Immunoreactivity was present in the neuropil, which delineated groups of cells with unstained cytoplasm. Many of the SCN cells were aggregated into cords or clusters. The optic chiasm was free from label, except for short processes apparently extending from the densely stained neuropil in the ventrolateral SCN. Immunoreactivity was abolished by preincubating sections in an endoneuraminidase (endo-N) or by preincubation of the primary antibody with PSA-NCAM. Immunostaining of the nonsialylated NCAM polypeptide was also limited to the neuropil, but this was more diffuse and less regionally specific than PSA staining. The ventral SCN exhibited the most intense labeling for NCAM. Immunoblot analyses revealed the immunoreactive PSA-NCAM as a broad band migrating between apparent molecular weights in the range of 150-300 kD, which was ablated by treatment of SCN tissue extract with endo-N. This electrophoretic migration pattern of PSA-NCAM from the SCN region was similar to that seen in several other brain regions.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Comparative studies of baculovirus granulins and polyhedrins.

Granulins and polyhedrins from five baculoviruses exhibit similar chemical and physical properties. Although similarities are demonstrated, it has been shown that each of the proteins is different and apparently specific to a given virus. The granulins and polyhedrins exhibit a major polypeptide component of an estimated molecular weight of 28,000. Alkaline protease activity has been detected in each preparation. N-terminal analyses reflect differences between granulins and polyhedrins studied: granulosis virus = Asx, and nuclear polyhedrosis virus = Glx. Two-dimensional high-voltage electrophoresis of highly purified granulin and polyhedrin preparations reveals relatedness as well as differences among the proteins as assessed by electrophoretic migration patterns.

Amino Acids↗
PubMed1975

Genetic distance analysis of twenty-two South American Indian populations.

Extent of genic variability among 22 tribal groups of South American Indians in terms of net codon differences per locus has been studied on the basis of determinations on ten genetic systems. The possibility of more than one (other than the north-south route, considered by others) migrational pattern is discussed in the light of the existing genetic variability among the Andean highland and the jungle populations. Genic similarities (as measured by gene identity) are related with geographic proximities which reflect the importance of random genetic drift in creating the present genic divergence among these population groups. Although the materials used in this paper form probably only a non-random sample of structural genome, intralocus variance (sampling) is found to contribute only a little in the variabilities of heterozygosity or genetic distance.

Bolivia↗
PubMed1984

Migration of bone marrow lymphocytes in mice: immunofluorescent staining using antiallotype serum.

Bone marrow cells from CSW (Igha) mice were injected intravenously into the congeneic CWB (Ighb) mice. The lymphoid tissues of the recipient CWB mice were examined for donor type surface immunoglobulin (SIg)-positive cells using fluorescein isothiocyanate-conjugated antiallotype serum Ighb anti-Igha. Donor type SIg-positive cells were rarely found in the recipients immediately after injection. However, the donor type B cells increased in the recipient's spleen from days 1-2 and reached a plateau thereafter. The present method provides a useful means for studying the migration patterns and differentiation of bone marrow lymphocytes.

Animals↗
PubMed1995

Effect of donor age on response of skin grafts to gamma-interferon.

BACKGROUND: Failure of aged human epidermis to induce HLA-DR antigens after intradermal administration of gamma-interferon (IFN-gamma) has recently been observed. OBJECTIVE: The purpose of the study was to find out whether this observation reflects an intrinsic impairment in the aged skin or is rather due to an environmental factor. METHODS: Aged and young human skin grafted onto nude mice were injected with IFN-gamma, and the induction of HLA-DR, intercellular adhesion molecule-1 (ICAM-1) and Langerhans cell (LC) migration patterns were studied. RESULTS: Increased surface expression of both HLA-DR and ICAM-1 molecules by epidermal cells was observed in all grafts, after IFN-gamma injections, whereas a decrease in LC was found only in the young grafts. CONCLUSION: This study may indicate that the lack of response of aged skin to IFN-gamma is due to both intrinsic impairment in epidermal cell function and changes in function of cells outside the epidermis such as lymphocytes and endothelial cells.

Adult↗