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Biomedical subjects

M Peeters

Publications and source records attributed to M Peeters.

At least 181 records · Page 10Linked to original sources
PubMed1992

Isolation and characterization of a new chimpanzee lentivirus (simian immunodeficiency virus isolate cpz-ant) from a wild-captured chimpanzee.

OBJECTIVE: To assess the prevalence of infection with simian immunodeficiency virus (SIV) isolate cpz, a lentivirus closely related to HIV-1, in chimpanzees, and to obtain new SIVcpz isolates. METHODS: Forty-four wild-captured chimpanzees in Belgium and Côte d'Ivoire were tested for HIV and SIV antibodies. Virus was isolated from the peripheral blood lymphocytes of positive animals and characterized by electron microscopy, Western blot and radioimmunoprecipitation assay. RESULTS: One animal had antibodies that cross-reacted with HIV-1. A lentivirus was isolated and referred to as SIVcpz-ant. With regard to molecular weight patterns, SIVcpz-ant differs from SIVcpz-gab' an HIV-1-related virus isolated from a wild-captured chimpanzee in Gabon. The major core protein, the transmembrane and outer membrane glycoproteins of the SIVcpz-ant strain consistently had higher molecular weights. Significantly more HIV-1-positive sera reacted with the envelope proteins of the Gabonese SIVcpz-gab strain than with the SIVcpz-ant strain. CONCLUSIONS: This study shows that natural infection of wild-captured chimpanzees with an HIV-related virus may not be uncommon. The diversity of the two chimpanzee isolates, the different geographical origin and the absence of disease suggest that chimpanzees have not recently become SIVcpz-infected.

Animals↗
PubMed1992

Rifabutin and ethambutol do not help recurrent Crohn's disease in the neoterminal ileum.

We tested the efficacy of rifabutin and ethambutol in combination in healing severe recurrent Crohn's disease in the neoterminal ileum. Sixteen patients who had undergone an ileal resection with partial colectomy and ileocolonic anastomosis and who had severe recurrent lesions in the neoterminal ileum at baseline ileocolonoscopy were included in the study. The patients received rifabutin in a dose of 5 mg/kg together with ethambutol, 20 mg/kg. Ten patients were treated for 6 months; six patients dropped out because of adverse events. As no effect was observed after 6 months, five patients completed a 12-month therapy course. Follow-up ileocolonoscopy was performed at 3, 6, and 12 months. In none of the 10 patients who completed the 6-month trial and in none of the five patients who completed 12 months of therapy was endoscopic improvement of the lesions observed. In four patients the disease was clinically progressive, and two patients underwent a reresection after 6 and 8 months, respectively. This study shows that long-term therapy with rifabutin and ethambutol does not heal Crohn's disease in the neoterminal ileum and does not prevent recurrence of symptoms and complications.

Adult↗
PubMed1992

[Amino acids and trisomy 21].

The relative concentrations of plasmatic and urinary amino acids were analysed in 79 trisomic-21 patients, 322 mentally retarded non-trisomic patients, and 206 controls. No true amino acidopathy was found in 21-trisomy, but in plasma a deficit of serine and an excess of cysteine and lysine are highly significant. Excesses of cysteine, methionine, tyrosine, and methyl-histidine are also typical in urine. The increased activity of superoxide-dismutase, cystathionine-beta-synthase, and purine synthesis enzymes, together with the sensitivity to methotrexate, atropine, and dysthyroidism, are in accordance with this shift of equilibrium. A nutritional compensation seems worth investigating.

Amino Acids↗
PubMed1991

Prevalence of HTLV-I and HTLV-II infection in Gabon, Africa: comparison of the serological and PCR results.

A cluster sampling survey was performed in 1989 in Libreville, Gabon, to determine HTLV-I and HTLV-II prevalence and to compare the efficacy of polymerase chain reaction (PCR) and serology in detecting HTLV-I and HTLV-II infections. A total of 322 sera from adults were tested by ELISA and by Western blot (WB). The WB patterns were interpreted according to WHO criteria and those of the manufacturer. PCR analysis using primer pairs in the gag and pol region, with a specific probe for HTLV-I and HTLV-II, was performed on the lymphocytes of the 322 adults. In addition, 134/322 samples were re-tested with tax primers, in a second laboratory. Using WHO criteria, 8/322 (2.5%) samples were positive on WB and 25 were indeterminate; with the criteria of the kit, 26/322 (8.1%) were positive and 7 were indeterminate by WB. By PCR, 13 (4%) samples were positive, including 12 for HTLV-I (3.7%) and one for HTLV-II (0.3%). All 8 seropositive samples (by the WHO criteria) were positive by PCR, as were 4 out of 25 indeterminate samples. Only one out of 289 seronegative samples was positive by PCR. In contrast, only 12/26 positive samples by the kit criteria were confirmed by PCR. These results confirm the relatively high HTLV-I/II seroprevalence observed in Gabon. HTLV-I infection is preponderant, but HTLV-II is also present. The WHO criteria for WB give a better fit with PCR results than the kit criteria for WB. In the absence of a specific confirmatory test and based on the uncommon "seronegative" HTLV-I/II infection, the indication for PCR appears limited to the positive WB samples (to differentiate HTLV-I and II infection) and to the indeterminate WB samples.

Blotting, Western↗
PubMed1991

Effect of faecal stream diversion on recurrence of Crohn's disease in the neoterminal ileum.

Aphthous lesions recur in the neoterminal ileum within the first few months after curative resection of the distal ileum in patients with Crohn's disease. These lesions do not originate from microscopic disease that is already present at the time of surgery. To investigate the importance of faecal stream in the pathogenesis of recurrent Crohn's lesions, we have studied 5 patients with Crohn's disease who had ileal resection. After curative resection and ileocolonic anastomosis, a diverting terminal ileostomy was constructed 25-35 cm proximal to the anastomosis thereby excluding the neoterminal ileum, the anastomosis, and the colon from intestinal transit. After six months of exclusion, endoscopy of the ileocolon was undertaken and biopsy specimens were taken. Transit was then restored. Six months after reanastomosis further biopsy specimens were taken. These patients were compared with a control group of 75 patients with Crohn's disease who underwent a one-step ileal resection and ileocolonic anastomosis. None of the 5 patients had endoscopic lesions in the neoterminal ileum after six months of exclusion and biopsies did not show inflammatory changes characteristic of Crohn's disease. By contrast, 53 of 75 patients with one-step surgery had endoscopic recurrence in the neoterminal ileum within six months of surgery. All 5 patients had an important recurrence of disease, both endoscopically and histologically, at ileocolonoscopy six months after reanastomosis. Our findings strongly support the view that recurrence of Crohn's disease in the neoterminal ileum after curative ileal resection is dependent on faecal stream.

Adult↗
PubMed1991

Evaluation of a line immunoassay for simultaneous confirmation of antibodies to HIV-1 and HIV-2.

An anti-HIV-1/HIV-2 line immunoassay (LIA), using peptides and recombinant antigens was evaluated against commercially available Western blot tests for HIV-1 and HIV-2 antibodies. Two thousand one hundred and ten sera of European, African, and South American origin were used in the evaluation. The panel included 1066 sera with antibodies to HIV-1, 192 sera with antibodies to HIV-2, and 64 sera with antibodies to both. Using Western blot results interpreted according to the WHO criteria as a reference standard, the overall specificity obtained by this LIA was 100% and the sensitivity was 99.77% (97.51-100% for 95% confidence limits) when sera dually reactive in Western blot were included. Of the three sera negative in the LIA but positive in HIV-1 WB, two could be retested in a radioimmunoprecipitation assay and were negative. When dually reactive sera in the Western blot (WHO) were included, the LIA yielded 9.9% indeterminate results as compared with 15.5% for both assays (chi 2 = 29.30; p less than 0.001). Although only one HIV-2 specific peptide antigen (gp36) was used, the LIA yielded a specificity of 100% and a sensitivity of 100% as compared with the HIV-2 Western blot assay. When indeterminate results were included, the overall agreement between the LIA and the HIV-1 and HIV-2 Western blot (WHO criteria) was 89.9% and 90.1% respectively. These results indicate that the LIA provides reliable simultaneous detection of antibodies to HIV-1 and HIV-2, and at a cost which is substantially lower than the cost of Western blot tests.

Blotting, Western↗
PubMed1991

Human T-cell lymphotropic virus type I infection and pregnancy: a case-control study and 12-month follow-up of 135 women and their infants.

Human T-cell lymphotropic virus type I (HTLV-I) infection is common in Gabon, but its influence on pregnancy is unknown. A single case of acute T-cell leukemia in a pregnant woman has been reported in the literature, but, as far as we know, we present the first case-control study analyzing the relationship between HTLV-I seropositivity and the course and outcome of pregnancy. The study concerned 45 HTLV-I seropositive pregnant women matched with 90 seronegative pregnant women. None has clinical features of HTLV-I infection during pregnancy or during the year after delivery. HTLV-I seropositivity did not significantly affect the course or outcome of pregnancy. After losing maternal antibodies to HTLV-I, none of the infants had seroconversion to HTLV-I 1 year after birth. Filaria infection was correlated with HTLV-I seropositivity, but confounding factors may account for this observation.

Adult↗
PubMed1991

Determination of thiamin and its phosphate esters in cultured neurons and astrocytes using an ion-pair reversed-phase high-performance liquid chromatographic method.

A sensitive method, based on fluorescence detection, for the determination of thiamin derivatives after precolumn derivatization is described. The separation is achieved on a PRP-1 column using ion-pair reversed-phase HPLC. This method is especially well adapted to the detection of thiamin triphosphate in complex mixtures such as tissue extracts. The detection limit for TTP is 50 fmol. The contents of thiamin derivatives were determined in primary cultures of rat cerebellar granule neurons and cerebral astrocytes. The amount of TTP is about five times higher in neurons than in astrocytes. Thus in rat brain TTP seems to be essentially associated with neurons and the intracellular concentration is estimated to be about 0.2 microM. Our results suggest the existence, in nerve cells, of specific regulatory mechanisms not related to the blood-brain barrier and responsible for the maintenance of thiamin homeostasis in brain.

Animals↗
PubMed1991

Seroprevalence of retroviral infection in women with different fertility statuses in Gabon, western equatorial Africa.

Seroprevalence of retroviral infection (HIV-1, HTLV-1) in women with different fertility statuses was studied in Gabon (Western Equatorial Africa). The overall prevalence rate of HIV-1 was 1.4% and of HTLV-1, 6.8%. In the primary infertile women the age-adjusted prevalence rate of HIV-1 was significantly higher than in the fertile women (9.3% versus 0.7%) and in secondary infertile women (9.3% versus 2.1%). There was no difference in sero-prevalence of HTLV-1 among women with different fertility statuses, but a steady increase with age was seen. Concomitant infection with HTLV-1 and HIV-1 was observed in two women. In Gabon primary infertile women could be considered a risk group for HIV-1 infection.

Acquired Immunodeficiency Syndrome↗
PubMed1990

[Epidemiology of HTLV-I infection in its hyperendemic foci (Japan, tropical Africa, Caribbean)].

HTLV-1 infection is endemic in Japan, black Africa, the Caribbean and several regions of South America. In these foci, the infections is very heterogeneously distributed (variations from village to village, intrafamilial clustering). The virus is transmitted from mother to child, and breast feedings seems to play a major role. Sexual transmission is usually from man to woman. The frequency of transmission by blood transfusion must not be underestimated. It justifies the systematic detection of HTLV-1 infection in areas where it is economically feasible.

Africa, Eastern↗