Male genital schistosomiasis and haemospermia.
Explore the source record for details and available documents.
Africa↗
Biomedical subjects
G Harms
Publications and source records attributed to G Harms.
Anaerobic utilization of alkylbenzenes and n-alkanes from crude oil in an enrichment culture of denitrifying bacteria affiliating with the beta-subclass of Proteobacteria.
Denitrifying bacteria were enriched from freshwater sediment with added nitrate as electron acceptor and crude oil as the only source of organic substrates. The enrichment cultures were used as laboratory model systems for studying the degradative potential of denitrifying bacteria with respect to crude oil constituents, and the phylogenetic affiliation of denitrifiers that are selectively enriched with crude oil. The enrichment culture exhibited two distinct growth phases. During the first phase, bacteria grew homogeneously in the aqueous phase, while various C1-C3 alkylbenzenes, but no alkanes, were utilized from the crude oil. During the second phase, bacteria also grew that formed aggregates, adhered to the crude oil layer and emulsified the oil, while utilization of n-alkanes (C5 to C12) from the crude oil was observed. During growth, several alkylbenzoates accumulated in the aqueous phase, which were presumably formed from alkylbenzenes. Application of a newly designed, fluorescently labelled 16S rRNA-targeted oligonucleotide probe specific for the Azoarcus/Thauera group within the beta-subclass of Proteobacteria revealed that the majority of the enriched denitrifiers affiliated with this phylogenetic group.
Alkanes↗
Anaerobic oxidation of o-xylene, m-xylene, and homologous alkylbenzenes by new types of sulfate-reducing bacteria.
Various alkylbenzenes were depleted during growth of an anaerobic, sulfate-reducing enrichment culture with crude oil as the only source of organic substrates. From this culture, two new types of mesophilic, rod-shaped sulfate-reducing bacteria, strains oXyS1 and mXyS1, were isolated with o-xylene and m-xylene, respectively, as organic substrates. Sequence analyses of 16S rRNA genes revealed that the isolates affiliated with known completely oxidizing sulfate-reducing bacteria of the delta subclass of the class Proteobacteria. Strain oXyS1 showed the highest similarities to Desulfobacterium cetonicum and Desulfosarcina variabilis (similarity values, 98.4 and 98.7%, respectively). Strain mXyS1 was less closely related to known species, the closest relative being Desulfococcus multivorans (similarity value, 86.9%). Complete mineralization of o-xylene and m-xylene was demonstrated in quantitative growth experiments. Strain oXyS1 was able to utilize toluene, o-ethyltoluene, benzoate, and o-methylbenzoate in addition to o-xylene. Strain mXyS1 oxidized toluene, m-ethyltoluene, m-isoproyltoluene, benzoate, and m-methylbenzoate in addition to m-xylene. Strain oXyS1 did not utilize m-alkyltoluenes, whereas strain mXyS1 did not utilize o-alkyltoluenes. Like the enrichment culture, both isolates grew anaerobically on crude oil with concomitant reduction of sulfate to sulfide.
Alkylation↗
Epithelial cell proliferative activity of Barrett's esophagus: methodology and correlation with traditional cancer risk markers.
Barrett's esophagus (BE) is a premalignant condition, due to chronic gastroesophageal reflux. Effective antireflux therapy may diminish cancer risk. To evaluate this option an intermediate marker is needed. We developed a methodology for measurement of epithelial cell proliferative activity of Barrett's mucosa as an intermediate marker and correlated the activity with traditional cancer risk markers and other parameters. Fifty-six patients (21-74 years of age) with Barrett's esophagus and established acid gastroesophageal reflux were included. Biopsies were taken from Barrett's mucosa at 3-cm intervals. Reflux was measured by 24-hr pH-metry. Proliferative activity was determined using in vitro labeling with 5-bromodeoxyuridine and immunohistochemistry and was expressed as labeling index (LI). The length of BE correlated with erect acid reflux (P=0.002). LI in specialized columnar metaplasia was higher than in gastric metaplasia, especially in crypt epithelium (P < 0.05). Multiple regression analysis revealed independent positive correlations for surface LI with dysplasia (P=0.011), distance from the incisors (P=0.041), and crypt LI (P=0.000). Crypt LI showed an independent positive correlation with the length of BE (P=0.033) and type of metaplasia (P=0.007). In conclusion, epithelial cell proliferative activity of BE correlates with several known risk factors for cancer. Proliferative activity is an attractive intermediate marker to evaluate the effects of interventional measures to decrease cancer risk in Barrett's esophagus.
Adenocarcinoma↗
Perceptions and patterns of reproductive tract infections in a young rural population in North-West Namibia.
Syndromic management of sexually transmitted diseases (STDs) is strongly promoted in Namibia. However, no data are available on rates of asymptomatic reproductive tract infections (RTIs) which would remain undetected and thus untreated in the general population. This study was aimed at assessing the prevalence of RTIs in a young rural population and to gain an insight into their health-care seeking behaviour for RTIs. A total of 97 patients (44 male, 53 female) <30 years of age attending the outpatient clinic of a rural hospital in Northern Namibia for problems unrelated to RTIs were interviewed and examined. Specimens were taken for investigation of RTIs according to a non-invasive diagnostic schedule. Laboratory examinations revealed 58 infections of the reproductive tract in 42 of the 97 patients (43%). In addition, HIV infection was detected in 13 cases (13%). RTI rates were highest in female teenagers (68%), but no infections were detected in their male counterparts. Of those 42 patients with a laboratory-diagnosed infection, 7 had both symptoms and signs (symptomatic), 16 had neither symptoms nor signs (asymptomatic), and 19 had signs on examination but no symptoms (inapparent). Awareness and perception of symptoms and signs of RTIs were low in the studied population. Provision of adequate treatment for RTIs alone is unlikely to have a major impact on the overall burden of disease since the largest burden of disease was found among those patients (predominantly females) with inapparent infections. Health education on RTIs including STDs and the symptoms they cause together with the importance of early attendance at health facilities and improved access to treatment need to be addressed urgently.
Adolescent↗
HIV-1 and AIDS awareness in a marginalised Namibian community.
Explore the source record for details and available documents.
Acquired Immunodeficiency Syndrome↗
Binding specificity of influenza C-virus to variably O-acetylated glycoconjugates and its use for histochemical detection of N-acetyl-9-O-acetylneuraminic acid in mammalian tissues.
The specificity of influenza C-virus binding to sialoglycoconjugates was tested with various naturally O-acetylated gangliosides or synthetically O-acetylated sialic acid thioketosides, which revealed binding to 9-O-acetylated N-acetylneuraminic acid. Binding was also observed with a sample of Neu5,7Ac2-GD3, however at a lower degree. Sialic acids with two or three O-acetyl groups in the side chain of synthetic sialic acid derivatives are not recognized by the virus. In these experiments, bound viruses were detected with esterase substrates. Influenza C-virus was also used for the histological identification of mono-O-acetylated sialic acids in combination with an immunological visualization of the virus bound to thin-sections. The occurrence of these sialic acids was demonstrated in bovine submandibular gland, rat liver, human normal adult and fetal colon and diseased colon, as well as in human sweat gland. Submandibular gland and colon also contain significant amounts of glycoconjugates with two or three acetyl esters in the sialic acid side chain, demonstrating the value of the virus in discriminating between mono- and higher O-acetylation at the same site. The patterns of staining showed differences between healthy persons and patients with colon carcinoma, ulcerative colitis or Crohn's disease. Remarkably, some human colon samples did not show O-acetyl sialic acid-specific staining. The histochemical observations were controlled by chemical analysis of tissue sialic acids.
Acetylation↗
Human immune response to pneumococcal polysaccharides: complement-mediated localization preferentially on CD21-positive splenic marginal zone B cells and follicular dendritic cells.
A functionally intact spleen with a marginal zone, containing B cells with high density of surface C3d-receptors (CD21), is essential for the ability to induce a primary immune response to thymus-independent type 2 (TI-2) antigens. Main representatives of natural TI-2 antigens are capsular pneumococcal polysaccharides (PPSs). In this study the localization of different types of PPS antigen is determined in human spleen tissue. Our findings indicate that a main type of TI-2 antigen, PPS, localizes preferentially in the marginal zone. PPSs show co-localization with C3, presumably C3d, at the surface of strongly CD21+ B cells equipped for rapid activation. This enables a rapid primary humoral response. The other main PPS localization at follicular dendritic cells in germinal centers, relevant for isotype switching of anti-PPS antibodies, does not seem to be dependent on the presence of specific immunoglobulin. This may explain the finding of specific IgG in an early stage after antigenic challenge. It seems likely that complement C3 fragments (likely C3d), bound to PPSs, enable PPS localization at B-cell and follicular dendritic cell surfaces by binding to CD21, the C3d receptor.
Adolescent↗
In vitro complement-dependent binding and in vivo kinetics of pneumococcal polysaccharide TI-2 antigens in the rat spleen marginal zone and follicle.
For a better understanding of the spleen-dependent induction of the humoral immune response against thymus-independent type 2 antigens, we have studied the in vitro and in vivo localization of different capsular pneumococcal polysaccharides (PPSs) in the rat spleen. In this study, we found that in vitro binding of PPS types 3, 4, 6B, 9N/V, 14, and 23F was dependent on complement (probably a C3 fragment) and that the localization was predominantly restricted to the marginal-zone B lymphocytes and the follicular dendritic cells. In vivo, we observed with increase of time a shift of localized antigens. Shortly after injection, all PPS types localized in the marginal-zone B lymphocytes, then localized in the outer follicular mantle, and finally were found to be diffuse in the complete follicle and follicle corona. PPS types 3 and 9N/V and later also PPS type 23F localized additionally in red pulp macrophages. In particular, the localization in the marginal zone is important since the low flow in this area in combination with strongly CD21+ B cells, which are activated early, gives a maximum opportunity for the induction of a primary humoral immune response with subsequent differentiation into plasma cells or migration to the germinal center. In addition, the localization of PPSs at follicular dendritic cells should be considered important in the induction of an ongoing immune response not restricted to the spleen.
Animals↗
[Generalized molluscum contagiosum in an African child with AIDS].
A 12-year-old girl from Zaire with AIDS (CDC: P2 D1) presented with a generalized molluscum contagiosum infection. She had suffered from systemic cryptococcosis and from cryptosporidiosis several months before admission. While molluscum contagiousum infection is usually a self-limiting disease in immunocompetent persons, a fulminant appearance and persistence of giant mollusca occurs with advanced immunodeficiency. Histological and immunohistological examinations showed a severe diminution of Langerhans and T cell populations that might enhance the dissemination of the infection. Molluscum-like lesions of cryptococci have been described, and cutaneous cryptococcosis is the main condition to be considered in the differential diagnosis. Further differential diagnoses should include American and African histoplasmosis, and the cutaneous manifestations of mycobacterial infections, of toxoplasmosis and of Pneumocystis carinii infection.
AIDS-Related Opportunistic Infections↗
Magnetic resonance imaging in brachial plexopathy of cancer.
We retrospectively reviewed the clinical records of all patients with cancer and brachial plexopathy who had an MRI of the brachial plexus between 1984 and 1993 (71 patients). The MRIs were reevaluated in a blinded fashion. The presence of a mass adjacent to the brachial plexus on MRI was highly predictive of tumor infiltration as determined by clinicopathologic criteria and was the most useful feature in distinguishing radiation plexopathy from tumor infiltration. Increased T2 signal in or near the brachial plexus was commonly seen in both groups and was not useful in this distinction. MRI was very sensitive for brachial plexus abnormalities in this condition, and limited comparison with CT suggested that MRI is superior to CT as an imaging modality. CT performed sufficiently well, however, to suggest that a prospective comparison study of the cost effectiveness and clinical utility of the two imaging modalities in this clinical setting is warranted.
Brachial Plexus↗
HIV and syphilis in Madagascar.
Explore the source record for details and available documents.
AIDS Serodiagnosis↗
Recognition of AIDS by health personnel in rural south-Rwanda.
The ability of rural health personnel to recognise AIDS related symptoms and signs according to the WHO clinical case definition (CCD) and its modified Rwandan version was tested in 4141 clinically suspected cases in South-Rwanda. The sensitivities of these CCDs for AIDS in adults were 33% (36%), the specificities 78% (76%), and the positive predictive values (ppv) 46%. For AIDS in children the sensitivities of the CCDs were 13% (16%), the specificities 94% (90%), and the ppv 44% (38%). While the specificities did not differ from those found in studies conducted by trained physicians, the low sensitivities and predictive values demand improvement of the training of the health personnel to diagnose AIDS related symptoms and signs, especially where laboratory tests are not available.
AIDS Serodiagnosis↗
Pharmacokinetic analysis and cellular distribution of the anti-HIV compound succinylated human serum albumin (Suc-HSA) in vivo and in the isolated perfused rat liver.
After intravenous injection of a low dose (25 micrograms/kg) in rats, the anti HIV-1 compound succinylated human serum albumin (Suc-HSA) is taken up mainly in the liver and spleen and is proteolytically degraded. Ten minutes after injection of 125I-Suc-HSA, 72 and 14% of the dose were found in the liver and spleen, respectively. With immunohistochemistry we demonstrated that in both organs, Suc-HSA was specifically endocytosed in endothelial cells. In the isolated perfused rat liver preparation, liver uptake was shown to be saturable, with a Km of 2.9 10(-8) M and a Vmax of 2.4 micrograms/min/100 g body weight. The apparent Km and Vmax in vivo were 2.2 10(-7) M and 10.3 micrograms/min/100 g, respectively. Uptake in liver and spleen was inhibited by preadministration of an excess of formaldehyde-treated albumin and with polyinosinic acid, indicating the involvement of the scavenger receptor, as anticipated for such polyanionic compounds. Suc-HSA is not absorbed intact from the colon and the ileum. After injecting (i.v.) rats with a high dose of Suc-HSA (10 mg/kg), the elimination t1/2 was 3 hr, and therefore, sustained plasma levels above the concentration needed for in vitro anti-HIV-1 activity can be achieved.
Animals↗
Immunochemotherapy of visceral leishmaniasis: a pilot trial of sequential treatment with recombinant interferon-gamma and pentavalent antimony.
The clinical, parasitological, hematological, and serological evolution of visceral leishmaniasis in Brazilian patients was assessed during treatment with human recombinant interferon-gamma (rIFN-gamma; 0.1 mg/m2 i.m. days 1-14) followed by pentavalent antimony (Sbv; 10 mg/kg days 22-28). At day 30, 6 patients had improved, 2 had slightly improved, and 1 patient had deteriorated. IFN-gamma was well tolerated in the dose tested and may be very effective as an adjunct to conventional therapy with antimony.
Adolescent↗
Trichinosis: a prospective controlled study of patients ten years after acute infection.
The existence of chronic trichinosis as a disease entity is still a matter of debate. For 10 years after an outbreak of infection with Trichinella spiralis, we conducted a prospective controlled study of the patients involved. At the termination of this investigation, we undertook clinical, biochemical, serological, immunologic, neuroradiological, radiological, and psychological studies of 128 originally infected persons and 16 controls. The categories of symptoms most often documented in persons who had been infected were muscular (90%), ocular (59%), neurological (52%), and psychological (52%). Impaired muscle strength (56%), conjunctivitis (55%), and impaired coordination (32%) were the clinical manifestations most frequently encountered. Thirty-eight percent of the 128 originally infected patients still had IgG antibodies to T. spiralis after 10 years. Magnetic resonance imaging of the brain revealed no abnormalities. No calcifications of residual larvae were detected by mammography or muscle biopsy. The level of performance in psychometric tests was lower in the originally infected population than in the general population. Although patients who had had trichinosis differed significantly from controls in terms of a variety of parameters even after 10 years, we found insufficient evidence on which to conclude that chronic trichinosis exists as a distinct entity.
Adult↗
Gamma delta T lymphocytes in oriental cutaneous leishmaniasis: occurrence and variable delta gene expression.
It has been suggested that T lymphocytes expressing gamma delta T-cell receptors could play an important role in defence against some intracellular infectious pathogens. The present study was undertaken to characterize the occurrence and variable delta gene expression of T lymphocytes expressing the gamma delta T-cell receptor in oriental cutaneous leishmaniasis. Eleven cases of oriental cutaneous leishmaniasis were investigated by immunohistological analysis using an alkaline phosphatase-anti-alkaline phosphatase (APAAP) technique. In three cases, we observed an increased percentage of gamma delta T cells (about 20% of CD3+ cells). In these cases gamma delta T cells generally expressed the V delta 2 segment, and only rarely the V delta 1 gene product. V delta 2+ cells were predominantly localized in the dermis, and were virtually absent in the epidermal compartment. The rare gamma delta T cells observed in the epidermis were almost exclusively V delta 1+. This study demonstrates that an increase of gamma delta T cells may be found in oriental cutaneous leishmaniasis, although it is not a constant feature of the disease. The finding of a preferential expansion of the V delta 2 subset suggests that this subpopulation of gamma delta T cells might be selectively involved in the recognition of Leishmania antigens. The distinct compartmentalization of gamma delta T-cell subpopulations indicates that these subsets may recognize distinct sets of antigens.
Antigens, Protozoan↗
Molecular analysis of the gamma delta T-cell receptor repertoire in normal human skin and in Oriental cutaneous leishmaniasis.
The extent of diversity of the gamma delta T-cell receptor (TCR) in normal human skin and Oriental Cutaneous Leishmaniasis (OCL) was examined by molecular analysis of the variable (V) delta gene segment, junctional (J) delta gene segment and junctional regions. To examine the expression of TCR delta genes, segments of gamma delta T lymphocytes, DNA isolated from normal human skin and from OCL were subjected to enzymatic gene amplification by the polymerase chain reaction (PCR) method using TCR V delta- and J delta-specific oligonucleotides as primers. PCR amplification using these primers indicated that the V delta 2 gene segment was predominantly used by gamma delta T lymphocytes in both normal human skin and OCL. To determine the extent of junctional diversity in the delta gene of gamma delta T cells in normal human skin and OCL, we sequenced the nucleic acid sequences corresponding to the V delta 2/J delta 1 junctional regions. Sequence analysis of junctional regions demonstrated broad junctional diversity in normal skin but only limited diversity in OCL. Our findings support the hypothesis that skin gamma delta T lymphocytes may derive from a fetal subset of gamma delta T lymphocytes that leaves the thymus early and colonizes the periphery. The limited junctional diversity demonstrated in OCL lesions indicates that gamma delta T cells can undergo oligoclonal expansion following recognition of a specific ligand and supports the idea that junctional regions are important in the recognition of antigenic determinant.
Amino Acid Sequence↗