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PubMed1990

Transition dynamics of HIV disease in a cohort of African prostitutes: a Markov model approach.

The progression of HIV-related disease from infection to death is represented as a staged Markov model. Transitions between stages are considered reversible. The model is fitted to data from a cohort of African prostitutes by means of maximum likelihood. It appears that the progression to symptomatic disease (Centers for Disease Control stage IV) in this population is considerably more rapid than that reported from studies in Western countries.

Acquired Immunodeficiency Syndrome↗
PubMed2006

Williamsia deligens sp. nov., isolated from human blood.

The taxonomic status of two bacterial strains isolated from human blood was characterized using a polyphasic approach. Chemotaxonomic investigations revealed the presence of cell-wall chemotype IV, short-chain mycolic acids that co-migrated with those extracted from members of the genus Williamsia and that produce C(16 : 0) and C(18 : 0) fatty acids on pyrolysis GC, and dihydrogenated menaquinone with nine isoprene units as the predominant isoprenologue. The generic assignment was confirmed by 16S rRNA gene sequencing. Comparative analysis of the 16S rRNA gene sequence showed that these isolates constitute a distinct phyletic line within the genus Williamsia, displaying 96.2 and 97.2 % sequence similarities to Williamsia muralis and Williamsia maris, respectively. The two isolates could be distinguished from the type strains of the latter species on the basis of several phenotypic traits. The genotypic and phenotypic data show that the strains merit classification as a novel species of Williamsia, for which the name Williamsia deligens sp. nov. is proposed, with type strain IMMIB RIV-956T (= DSM 44902T = CCUG 50873T).

Actinomycetales↗
PubMed2006

Dietzia cinnamea sp. nov., a novel species isolated from a perianal swab of a patient with a bone marrow transplant.

The taxonomic status of a bacterium isolated from a perianal swab of a patient with a bone marrow transplant was characterized using a polyphasic taxonomic approach. Chemotaxonomic investigations revealed the presence of cell wall chemotype IV, short chain mycolic acids that co-migrated with those extracted from members of the genus Dietzia, and a dihydrogenated menaquinone with eight isoprene units as the predominant menaquinone. Generic assignment was confirmed by 16S rRNA gene sequencing. Comparative analysis of the 16S rRNA gene sequence showed that this isolate constitutes a distinct phyletic line within the genus Dietzia, displaying 97.5-98.7% sequence similarity with Dietzia species with validly published names. The isolate could be distinguished from the type strain of Dietzia maris (1.6% sequence divergence) and other species of the genus Dietzia by DNA-DNA hybridization, as well as by using a set of biochemical tests. Genotypic and phenotypic data show that the strain merits classification as a novel species of the genus Dietzia for which the name Dietzia cinnamea sp. nov. is proposed; the type strain is IMMIB RIV-399T (= DSM 44904T = CCUG 50875T).

Actinomycetales↗
PubMed1997

The microbial ecology and immunology of the adenoid: implications for otitis media.

The nasopharyngeal tonsil, or adenoid, is a major inductive site for the synthesis of J-chain-positive B cells that may migrate to other areas of the upper respiratory tract, such as the nasal mucosa, the parotid gland, the lacrimal gland, and the middle ear during inflammation. The production of secretory IgA by both the nasopharyngeal tonsil and the nasal mucosa plays a major role in local immune protection against bacteria and viruses. The release of cytokines from Th1 and Th2 lymphocytes must be appropriate for B cells to produce IgA. The factors or mechanisms responsible for this are not, at present, known, but it appears that there is a difference in the profiles of cytokine secretion by Th1 and Th2 lymphocytes in the adenoids in both otitis-prone, as well as nonotitis-prone children. We have suggested that if this specific immune system does not protect the host from invasion by potential pathogens, there are other modalities of therapy to protect the nasopharynx from colonization with pathogenic bacteria or viruses. These include the production of specific antibodies against bacterial surface proteins that have been identified as mucin-binding proteins. Alteration of the microbial flora with commensal organisms such as viridans streptococci can be utilized. These alpha-hemolytic streptococci probably function by producing an acid environment that prevents colonization of organisms such as nontypeable H. influenzae. Finally, the induction of specific SIgA by conserved outer membrane protein antigens of potential pathogens may be another strategy in the prevention of colonization of potential bacterial pathogens in the nasopharynx.

Adenoids↗
PubMed1980

Differential solubility and subunit composition of rat glomerular basement membrane.

Glomerular basement membrane (GBM) was prepared from 2- to 3-month-old Sprague-Dawley rats by differential sieving and sonication. 80% of the membrane was soluble in 1% sodium dodecyl sulphate (SDS) and 1% 2-mercaptoethanol. The soluble fraction was resolved into 15 bands in the molecular weight range 30,000 to 300,000 by SDS-polyacrylamide gel electrophoresis. The major bands present had apparent molecular weights of 100,000 and 148,000. Treatment of GBM with SDS alone solubilised mainly low molecular weight components (45,000-150,000) but when the residue was treated with SDS and 2-mercaptoethanol higher molecular weight material was solubilised. Partial solubilisation of GBM was also achieved with pepsin. Digestion for 18 h at 4 degrees C resulted in 20% of the membrane being solubilised but this was increased to 55% at 10 degrees C. The amino-acid composition of pepsin-soluble GBM was more collagen-like than the residue remaining after enzyme digestion. Although the residue was more polar than whole GBM it still contained significant amounts of glycine and hydroxyproline and could be further subfractionated with SDS into a soluble fraction, the amino acid content of which was similar to whole GBM and a collagenous residue containing 317 residues/1,000 of glycine. When pepsin solubilised GBM was subjected to horizontal electrophoresis in SDS-polyacrylamide slab gels the principal bands migrated in the pro-alpha-chain region. This material was heterogeneous and in addition to the principal components, 6 components with apparent molecular weights less than 95,000 were present together with high molecular weight material in the gamma and beta regions of the gel. The band pattern of the pepsin-insoluble material was similar although the intensities of some individual bands varied significantly from that of the pepsin-soluble material. Rat GBM can therefore be fractionated by treatment with SDS alone, SDS together with 2-mercaptoethanol and pepsin digestion. The data reported is compatible with the presence of a mixture of collagen-like and polar regions rather than a major single collagenous component (type IV collagen).

Amino Acids↗
PubMed2004

Circulating mononuclear cells in the obese are in a proinflammatory state.

BACKGROUND: In view of the increase in plasma concentrations of proinflammatory mediators tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and C-reactive protein (CRP) in obesity, we investigated whether peripheral blood mononuclear cells (MNC) from obese subjects are in a proinflammatory state. METHODS AND RESULTS: MNC were prepared from fasting blood samples of obese (n=16; body mass index [BMI]=37.7+/-5.0 kg/m2) and normal-weight control (n=16; BMI=23.8+/-1.9 kg/m2) subjects. Nuclear factor kappaB (NF-kappaB) binding to DNA in nuclear extracts was elevated (P<0.05) and the inhibitor of NFkappaB-beta (IkappaB-beta) was significantly lower (P<0.001) in the obese group. Reverse transcription-polymerase chain reaction revealed elevated levels of migration inhibitor factor (MIF), IL-6, TNF-alpha, and matrix metalloproteinase-9 (MMP-9) mRNA expression in the obese subjects (P<0.05). Plasma concentrations of MIF, IL-6, TNF-alpha, MMP-9, and CRP were also significantly higher. Plasma glucose, insulin, and free fatty acids (FFAs) were measured, and homeostasis model assessment of insulin resistance (HOMA-IR) was calculated. Plasma FFA concentration related significantly to BMI, IL-6, and TNF-alpha mRNA expression and plasma CRP levels but not to HOMA-IR. On the other hand, the inflammatory mediators were significantly related to BMI and HOMA-IR. CONCLUSIONS: These data show (1) for the first time that MNC in obesity are in a proinflammatory state with an increase in intranuclear NF-kappaB binding, a decrease in IkappaB-beta, and an increase in the transcription of proinflammatory genes regulated by NF-kappaB; (2) that plasma FFAs are a modulator of inflammation; and (3) that insulin resistance is a function of inflammatory mediators.

Adult↗
PubMed2002

Pamidronate treatment of osteogenesis imperfecta--lack of correlation between clinical severity, age at onset of treatment, predicted collagen mutation and treatment response.

UNLABELLED: Severe forms of osteogenesis imperfecta (OI) are characterised by osteoporosis with multiple fractures, deformity, progressive loss of mobility and chronic bone pain. Bisphosphonates, as osteoclast inhibitors, reduce bone turnover and improve osteoporosis. OBJECTIVE: To investigate the effect of pamidronate treatment of severe OI in children, and find any correlation between clinical severity, age at start of treatment, type of predicted collagen mutation and treatment response. DESIGN: Open, observational trial. PATIENTS: A two-year study of pamidronate treatment was undertaken in a cohort of 18 children, (1.4-14.5 years) with OI types III and IV. INTERVENTIONS: Disodium pamidronate, 1 mg/kg/day for 3 days every 4 months, by i.v. infusion with measurement of bone turnover, bone density, vertebral morphology and skin biopsies to assess collagen mutation. RESULTS: Eleven children have completed 2 years of treatment and three more have completed 20 months. Sustained cessation of bone pain, improved mobility and decreased fracture rate were seen in all patients. Bone turnover decreased slightly but was not statistically significant. Bone mineral density (BMD) of lumbar spine increased by a mean of 124.7 +/- 75.7% over 2 years (Z score mean -5.08 +/- 1.27, to -3.30 +/- 1.71, p <0.001); the greatest change in BMD was seen in the most severely affected patients: 138 +/- 50.6% (severe), 62.47 +/- 22.9% (mild). There was a mean increase in vertebral height at L4 of 68.5% and in vertebral area of 85.4%. The majority of patients had slow electrophoretic migration of type I collagen alpha chains or reduced secretion of type I collagen, indicative of structural, helix-breaking mutations. There was no correlation between phenotypic severity, age at start of treatment and treatment response (r2 = 0.14) CONCLUSIONS: Pamidronate treatment of severe forms of OI is an effective therapeutic modality to increase bone density, decrease fracture rate, increase mobility and improve quality of life, irrespective of the severity of the mutation or clinical phenotype. It has a good short-term safety profile.

Adolescent↗
PubMed2006

Cell migration along the lateral cortical stream to the developing basal telencephalic limbic system.

During embryogenesis, the lateral cortical stream (LCS) emerges from the corticostriatal border (CSB), the boundary between the developing cerebral cortex and striatum. The LCS is comprised of a mix of pallial- and subpallial-derived neural progenitor cells that migrate to the developing structures of the basal telencephalon, most notably the piriform cortex and amygdala. Using a combination of in vitro and in vivo approaches, we analyzed the timing, composition, migratory modes, origin, and requirement of the homeodomain-containing transcription factor Gsh2 (genomic screened homeobox 2) in the development of this prominent migratory stream. We reveal that Pax6 (paired box gene 6)-positive pallial-derived and Dlx2 (distal-less homeobox 2)-positive subpallial-derived subpopulations of LCS cells are generated in distinct temporal windows during embryogenesis. Furthermore, our data indicate the CSB border not only is comprised of separate populations of pallial- and subpallial-derived progenitors that contribute to the LCS but also a subpopulation of cells coexpressing Pax6 and Dlx2. Moreover, despite migrating along a route outlined by a cascade of radial glia, the Dlx2-positive population appears to migrate primarily in an apparent chain-like manner, with LCS migratory cells being generated locally at the CSB with little contribution from other subpallial structures such as the medial, lateral, or caudal ganglionic eminences. We further demonstrate that the generation of the LCS is dependent on the homeodomain-containing gene Gsh2, revealing a novel requirement for Gsh2 in telencephalic development.

Animals↗
PubMed1988

The 4-6-8 method of sequence analysis.

A new method to obtain more sequence data from a single gel run is described. This method allows the reading of over 500 bases of sequence data from a single gel by taking advantage of the differential migration of specific sized dideoxy terminated chain lengths in sequencing gels containing variable percentages of acrylamide. The method is easy to use, requires no special equipment and requires no special technical abilities. We feel the methodology described will be useful for the average laboratory doing sequencing work.

Base Sequence↗
PubMed1982

Synthesis of immunoglobulins by human endocervix in organ culture.

The synthesis of immunoglobulins by the uterine cervix was investigated in an endocervical organ-culture system. Using Ouchterlony immunodiffusion gels immunoglobulin G, immunoglobulin A and secretory piece were detected in washings of endocervical explants and in explant incubation medium. Synthesis of immunoglobulin in the organ-culture system was investigated by polyacrylamide-gel electrophoresis of radiolabelled polypeptides; 2 polypeptides co-migrated with the heavy and light chains of a reference polyclonal immunoglobulin G and were confirmed, by use of anti-human globulin and iodinated staphylococcal protein A, to be the heavy and light chains of immunoglobulin G. This experimental system will provide a useful model in future investigations of the efficacy of a local vaccine in human subjects.

Adult↗
PubMed1994

[Trans-uranium elements in food products (review)].

The data of Russian and foreign authors concerning of level environmental contamination and migration of transuranic elements in food chains, metabolism and biological danger of nuclides entering in human body with foods are reviewed. A level of radionuclide load of population and doses of radiation are discussed and the danger is estimated. The doses of radiation from radionuclide ingestion are lower than level of allowed radiation safety standards.

Animals↗
PubMed1998

The chemokine receptor CXCR-4 is expressed on CD34+ hematopoietic progenitors and leukemic cells and mediates transendothelial migration induced by stromal cell-derived factor-1.

The chemokine stromal cell-derived factor-1 (SDF-1) and its receptor CXCR-4 (fusin, LESTR) are likely to be involved in the trafficking of hematopoietic progenitor and stem cells, as suggested by the reduced bone marrow hematopoiesis in SDF-1-deficient mice and the chemotactic effect of SDF-1 on CD34+ progenitor cells. Migration of leukemic cells might also depend on the expression of chemokine receptors. Therefore, we analyzed expression of CXCR-4 on mobilized normal CD34+ progenitors and leukemic cells. In addition, SDF-1-induced transendothelial migration across a bone marrow endothelial cell layer was assessed in vitro. By flow cytometry, CXCR-4 was found to be expressed in significant amounts on circulating CD34+ hematopoietic progenitor cells, including more primitive subsets (CD34+/CD38- and CD34+/Thy-1+ cells). In accordance with the immunofluorescence data, CD34+ progenitors efficiently migrated across endothelium in response to SDF-1 containing conditioned medium from the stromal cell line MS-5. Leukemic blasts (mostly CD34+) from patients with acute myeloblastic leukemia (AML) expressed variable amounts of CXCR-4, which was functionally active, as demonstrated by a positive correlation between the SDF-1-induced transendothelial migration and the cell surface density of CXCR-4 (r = 0.97). Also recombinant SDF-1beta induced migration of CXCR-4-positive leukemic blasts. The effect of both conditioned medium and recombinant SDF-1 was inhibited by a CXCR-4 blocking antibody. In contrast, CD34+ leukemic cell lines (KG1, KG1a, Kasumi-1, MOLM-1) expressed low levels or were negative for CXCR-4, and did not migrate. By reverse transcriptase-polymerase chain reaction (RT-PCR), however, basal levels of CXCR-4 mRNA were also detected in all leukemic cell lines. We conclude that CXCR-4 is expressed on CD34+ cells including more primitive, pluripotent progenitors, and may therefore play a role in the homing of hematopoietic stem cells. CXCR-4 expressed in variable amounts on primary AML leukemic cells is functionally active and may be involved in the trafficking of malignant hematopoietic cells.

Antigens, CD34↗
PubMed1999

Role of epidermal growth factor receptor in basal and stimulated colonic epithelial cell migration in vitro.

Colonic mucosal wounds are repaired, in part, by epithelial migration. Signaling mechanisms regulating this migration are poorly characterized. This study aimed to examine the role that the epidermal growth factor (EGF) receptor (EGF-R) and its ligands, EGF and transforming growth factor-alpha (TGF-alpha), play in migration in wounded in vitro models of colonic epithelium. Migration was assessed over 24 h in circular wounds made in confluent monolayers of LIM1215 human colon cancer cells. EGF and TGF-alpha stimulated migration twofold from 4 h after wounding. Basal migration and the motogenic effects of short chain fatty acids and hepatocyte growth factor were mediated through enhanced binding of TGF-alpha to EGF-R, while trefoil peptide-mediated motogenesis required EGF-R activation independently of TGF-alpha binding. Activation of protein kinase C (PKC) stimulated migration, an effect more potent than, and independent of, EGF-R activation. However, neither inhibition of PKC by Ro 31-8220 nor depletion of PKC by pretreatement with phorbol myristate acetate attenuated EGF-R-mediated motogenesis. In conclusion, EGF-R activation via TGF-alpha binding, or intracellularly, mediates basal LIM1215 migration and the effects of several motogens, with the exception of PKC activators. Since EGF-R and PKC have physiological activators in vivo, they may control colonic mucosal repair processes following injury.

Acetates↗
PubMed2000

Increased migration in late G(1) phase in cultured smooth muscle cells.

Migration and proliferation of smooth muscle cells (SMC) contribute to neointimal formation after arterial injury. However, the relation between migration and proliferation in these cells is obscure. To discriminate between migration and proliferation, we employed a migration assay of SMC at different phases of the cell cycle. Serum-deprived SMC were synchronized in different phases of the cell cycle by addition of serum for various periods of time. Migration induced by platelet-derived growth factor B-chain homodimer was maximal in SMC that were predominantly in the late G(1) (G(1b)) phase. In addition, in nonsynchronized SMC, 65-75% of SMC that had migrated were in the G(1b) phase. Phosphorylated myosin light chain was enriched around the cell periphery in SMC in the G(1b) phase compared with SMC in the other cell cycle phases. Interestingly, the Triton X-100-insoluble fraction of myosin was remarkably decreased in G(1b)-enriched SMC. These findings suggest that migratory activity of SMC may be coupled with the G(1b) phase. The phosphorylation and retention of myosin might explain some of the properties responsible for increased migration.

Actins↗
PubMed2000

Analysis of hemoglobin and globin chain variants by a commonly used capillary isoelectric focusing method.

To analyze both hemoglobin (Hb) and globin chain variants, we modified a commonly used method, capillary isoelectric focusing (CIEF), with detection at 280 nm. The samples were hemolysates prepared from red blood cells, and globin chains obtained from the hemolysates by treatment with cold acidified acetone. When the migration time for the internal reference, carbonic anhydrase I (isoelectric point, pI 6.60), was taken as 1.0, the migration ratio for Hb A0 in normal human blood was 0.877 +/- 0.004 (mean +/- SD, n = 9), and those of the alpha- and beta-globin chains were 0.673 +/- 0.004 and 0.847 +/- 0.005 (mean +/- SD, n = 4), respectively. The ratio of peak heights between the beta- and alpha-globin chains (beta/alpha) in the normal Hbs obtained from four subjects was almost constant at 2.5 +/- 0.1 (mean +/- SD). This ratio indicates which of the globin chains includes a mutation (if one exists). When an Hb variant, Hb Hoshida (in which Gln is substituted for Glu at residue 43 in the beta-globin chain), was analyzed by this method, two main peaks were observed (migration ratios 0.836 and 0.877, corresponding to an abnormal and the normal Hb, respectively). An additional peak with an abnormal migration ratio of 0.788 was also detected in the globin chain profiles. The ratio of peak heights between normal beta- and alpha-globin chains was 1.57, indicating that a mutation exists in the beta-globin chain. We thus established a convenient system using CIEF that provides a rapid and reproducible method for the random analysis of both Hb and globin chain variants.

Electrophoresis, Capillary↗
PubMed1991

Comparison of myosin isoenzymes present in skeletal and cardiac muscles of the Arctic charr Salvelinus alpinus (L.). Sequential expression of different myosin heavy chains during development of the fast white skeletal muscle.

The expression of myosin isoforms and their subunit composition in the white skeletal body musculature of Arctic charr (Salvelinus alpinus) of different ages (from 77-day embryos until about 5 years old) was studied at the protein level by means of electrophoretic techniques. Myosin from the white muscle displayed three types of light chain during all the developmental stages examined: two myosin light chains type 1 (LC1F) differing in both apparent molecular mass and pI, one myosin light chain type 2 (LC2F) and one myosin light chain type 3 (LC3F). The fastest-migrating form of LC1F seemed to be predominant during the embryonic and eleutheroembryonic periods. The slowest-migrating form of LC1F was predominant in the 5-year-old fish. Between 1 year and 4 years, both types of LC1F were present in similar amounts. Cardiac as well as red muscle myosin from 3-year-old fish had two types of light chain. The myosin light chains from atria and ventriculi were indistinguishable by two-dimensional electrophoresis, but were different from the myosin light chains from red muscle. Neither the light chains from cardiac nor red muscle were coexpressed with the myosin light chains of white muscle at any of the developmental stages examined. Two myosin heavy chain bands were resolved by SDS/glycerol/polyacrylamide gel electrophoresis of the extract from embryos. One of the bands was present in minor amounts. The other, and most abundant, band comigrated with the only band found in the extracts of white muscle myosin from older fish. One-dimensional Staphylococcus aureus V8 protease peptide mapping of these bands revealed some differences during development of the white muscle tentatively interpreted as follows. The myosin heavy chain band present in minor amounts in the embryos may represent an early embryonic form that is replaced by a late embryonic or foetal form in the eleutheroembryos. The foetal myosin heavy chain appears to be present until the resorption of the yolk sack and beginning of the free-swimming stage. A new form of myosin heavy chain, termed neonatal and probably expressed around hatching, is present until about 1 year of age.(ABSTRACT TRUNCATED AT 400 WORDS)

Aging↗