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Biomedical subjects

J Servais

Publications and source records attributed to J Servais.

At least 19 recordsLinked to original sources
PubMed2004

Simple DNA extraction method for dried blood spots and comparison of two PCR assays for diagnosis of vertical human immunodeficiency virus type 1 transmission in Rwanda.

Dried blood spots (DBS) on filter paper facilitate the collection, transport, and storage of blood samples for laboratory use. A rapid and simple DNA extraction procedure from DBS was developed and evaluated for the diagnosis of human immunodeficiency virus type 1 (HIV-1) infection in children by an in-house nested-PCR assay on three genome regions and by the Amplicor HIV-1 DNA prototype assay version 1.5 (Roche Molecular Systems). A total of 150 samples from children born to HIV-1-infected mothers were collected in Kigali, Rwanda, in parallel as DBS and as peripheral blood mononuclear cell (PBMC) pellets. The results obtained on DBS by the two PCR assays were compared to the results of nested PCR on PBMCs. Of 150 PBMC samples, 10 were positive, 117 were negative, and 23 were indeterminate for HIV-1 infection. In DNA extracted from filter papers and amplified by using the in-house nested PCR, 9 of these 10 positive samples (90%) were found to be positive, and 1 was found to be indeterminate (only the pol region could be amplified). All of the negative samples and all of the 23 indeterminate samples tested negative for HIV-1 infection. When we used the Amplicor DNA test on DBS, all of the 10 PBMC-positive samples were found to be positive and all of the 23 indeterminate samples were found to be negative. Of the PBMC-negative samples, 115 were found to be negative and 2 were found to be indeterminate. We conclude that this simple rapid DNA extraction method on DBS in combination with both detection methods gave a reliable molecular diagnosis of HIV-1 infection in children born to HIV-infected mothers.

Acquired Immunodeficiency Syndrome↗
PubMed2001

HIV-associated hematologic disorders are correlated with plasma viral load and improve under highly active antiretroviral therapy.

The relationship between HIV-1 replication and hematologic parameters was examined in two separate studies. The first study was a cross-sectional evaluation of 207 untreated patients. In this study, the proportion of patients with hematologic disorders increased with disease progression. There was a significant inverse correlation between HIV-1 plasma viral load and all hematologic values (r = -0.266 to -0.331). The second study was a longitudinal evaluation of patients on combination antiretroviral therapy (HAART) with hematologic alterations before treatment ( N = 27 with platelets <150,000/microl, 24 with hemoglobin <12 g/dl, 36 with neutrophils <2000/microl and 29 with leukocytes <3000/microl). Samples were analyzed every 3 months for 2 years. At 2 years, >50% of patients experienced a sustained virologic response, with viral loads <500 RNA copies/ml. Hematologic reconstitution occurred progressively for all blood cell lineages and became statistically significant after the sixth month of therapy ( p <.001). Mean values increased from 110 to 180 x 10(3)/microl for platelets, from 10.7 to 12.3 g/dl for hemoglobin (stabilizing finally at 11.4 g/dl), from 1,260 to 2,240/microl for neutrophils, and from 2,260 to 3,600/microl for leukocytes. In conclusion, hematologic disorders are corrected by combination antiretroviral therapy. This suggests a causative role of HIV-1 in hematologic disorders.

Adult↗
PubMed2001

Variant human immunodeficiency virus type 1 proteases and response to combination therapy including a protease inhibitor.

The objective of this observational study was to assess the genetic variability in the human immunodeficiency virus (HIV) protease gene from HIV type 1 (HIV-1)-positive (clade B), protease inhibitor-naïve patients and to evaluate its association with the subsequent effectiveness of a protease inhibitor-containing triple-drug regimen. The protease gene was sequenced from plasma-derived virus from 116 protease inhibitor-naïve patients. The virological response to a triple-drug regimen containing indinavir, ritonavir, or saquinavir was evaluated every 3 months for as long as 2 years (n = 40). A total of 36 different amino acid substitutions compared to the reference sequence (HIV-1 HXB2) were detected. No substitutions at the active site similar to the primary resistance mutations were found. The most frequent substitutions (prevalence, >10%) at baseline were located at codons 15, 13, 12, 62, 36, 64, 41, 35, 3, 93, 77, 63, and 37 (in ascending order of frequency). The mean number of polymorphisms was 4.2. A relatively poorer response to therapy was associated with a high number of baseline polymorphisms and, to a lesser extent, with the presence of I93L at baseline in comparison with the wild-type virus. A71V/T was slightly associated with a poorer response to first-line ritonavir-based therapy. In summary, within clade B viruses, protease gene natural polymorphisms are common. There is evidence suggesting that treatment response is associated with this genetic background, but most of the specific contributors could not be firmly identified. I93L, occurring in about 30% of untreated patients, may play a role, as A71V/T possibly does in ritonavir-treated patients.

Adult↗
PubMed2001

Comparison of DNA sequencing and a line probe assay for detection of human immunodeficiency virus type 1 drug resistance mutations in patients failing highly active antiretroviral therapy.

The resistance of human immunodeficiency virus type 1 (HIV-1) to drugs is a major cause of antiretroviral treatment failure. We have compared direct sequencing to a line probe assay (LiPA) for the detection of drug resistance-related mutations in 197 clinical samples, and we have investigated the sequential appearance of mutations under drug pressure. For 26 patients with virological failure despite the use of two nucleoside analogues and one protease inhibitor (indinavir [n = 6], ritonavir [n = 10], and saquinavir [n = 10]), genotypic resistance assays were carried out retrospectively every 3 months for up to 2 years by using direct sequencing (TruGene; Visible Genetics) and a LiPA for detection of mutations in the reverse transcriptase (INNO-LiPA HIV-1 RT; Innogenetics) and the protease (INNO-LiPA HIV Protease, prototype version; Innogenetics) genes. Comparison of the results from both assays found rare major discrepancies (<1% of codons analyzed). INNO-LiPA detected more wild-type-mutant mixtures than sequencing but suffered from a high rate of codon hybridization failures for the reverse transcriptase. LiPA detected earlier and more frequently than sequencing the transient mixed virus population that contained I84V, which appears before V82A in the protease sequence. Mutations M461, G48V, and L90M were often transient and drug pressure related. In conclusion, direct sequencing and LiPAs give concordant results for most clinical isolates. LiPAs are more sensitive for the detection of mixed virus populations. Mutation I84V appears in minor populations in the early steps of the pathways of resistance to indinavir and ritonavir. The fact that some mutations can be found only transiently and in minor virus populations highlights the importance of a low detection limit for resistance assays.

Acquired Immunodeficiency Syndrome↗
PubMed2001

Genotypic correlates of resistance to HIV-1 protease inhibitors on longitudinal data: the role of secondary mutations.

Direct sequencing of the pol gene was assessed retrospectively with protease inhibitor susceptibility in a longitudinal study. A total of 134 samples from 26 patients were analysed at regular intervals up to 2 years. Patients were included in virological failure despite indinavir, ritonavir or saquinavir based triple-drug therapy. Both the type and number of certain secondary protease mutations modulated the effect of primary mutations on phenotypic resistance. This was notably applicable to L101/V, and to lesser extents to A711V/T. However, combinations of primary mutations, including 154V could predict resistance to the drug used and nelfinavir in more than 80%. In contrast, in vitro cross-resistance to amprenavir was rarely encountered. In addition, there was a relationship between a higher number of key mutations and poorer virological and clinical outcomes, respectively, from 6 and 3 months on. The key mutations were the protease mutations independently conferring phenotypic resistance and/or the reverse transcriptase mutations predicting treatment outcome. This relationship was independent from drug history, viral load and CD4 cell count measurements. In summary, even on a small sample size, sequence-based genotyping seems to be a good prognostic marker when performed longitudinally. In the context of primary resistance mutations, including additional secondary mutations, it may be useful in the prediction of phenotypic and clinical resistance. This should be assessed to optimize treatment monitoring before emergence of broadly cross-resistant virus.

Acquired Immunodeficiency Syndrome↗
PubMed1999

Bone marrow content measured in radioimmune bone marrow scintigraphy: intra- and inter-observer variability.

The aim of this study was to assess the possible quantification of vertebral residual bone marrow content relative to the bone marrow content of a non-irradiated vertebra. This method is based on the vertebral count activity, measured using radioimmune bone marrow scintigraphy. First, however, we had to evaluate intra- and inter-observer variability. In three patients who underwent radioimmune bone marrow scintigraphy, two independent observers measured the count density in 51 (15 lumbar and 36 thoracic) vertebrae using a manually drawn region of interest. To evaluate intra- and inter-observer variability, we calculated the means and standard deviations of the differences between measurements. Bland-Altman plots were drawn for all vertebrae as well as for three subgroups of vertebrae (the upper thoracic spine, D1-D6; the lower thoracic spine, D7-D12; and the lumber spine, L1-L5). For all vertebrae, the mean (+/- S.D.) difference, expressed as a percentage of the overall mean, was -0.44 +/- 3.3% for observer 1 and -0.3 +/- 2.1% for observer 2 for intra-observer variability; inter-observer variability varied from 0.55 +/- 3.9% to 1.28 +/- 3.7%. On the Bland-Altman plots, the data points were evenly distributed above and below the 0-line and the linear regression equations matched the line of equality almost perfectly. This pattern was observed for all the vertebrae as well as for the subgroups of vertebrae. In conclusion, our results show that the intra- and inter-observer variabilities are not great, confirming that this technique is simple and robust and can be used for further quantification of bone marrow content in the axial skeleton.

Adult↗
PubMed1996

Generalized bone marrow metastases. High liver uptake on bone marrow immunoscintigraphy associated with extramedullary hematopoiesis.

Increased hepatic uptake and absent bone marrow uptake on bone marrow immunoscintigraphy has been reported after the formation of human antimurine antibodies. A case of generalized bone marrow metastases is presented, in whom an elevated liver uptake on bone marrow immunoscintigraphy proved to be associated with extramedullary hematopoiesis. Extramedullary hematopoiesis should be included as a possible cause of a disproportionately elevated liver uptake on bone marrow immunoscintigraphy, especially on initial studies, or on repeat studies with low human antimurine antibody titers. Tc-99m labeled BW 250/183 immunoscintigraphy may aid in the localization of suspected sites of extramedullary hematopoiesis.

Adult↗
PubMed1993

Hormonal therapy in the treatment of mandibular metastasis of breast carcinoma. Report of a case.

We present the clinical history of a 39-year-old woman, who has survived for over 10 years with metastatic breast cancer. After combined surgery and radiotherapy of the primary tumor and the regional lymph nodes, all bone metastases gradually disappeared under chemotherapy and continuing hormonal treatment. This complete remission included a large mandibular metastasis, which had received additional radiotherapy of 21 Gy. Spontaneous reossification was observed in this location.

Adult↗
PubMed1990

[Choosing one's furniture, one's dental chair in a more ergonomic style].

Setting up an ergonomic dental practice is sometimes more difficult than it seems. The current trend of combining fixed furniture with a fixed dentist's chair is far from being ergonomic. Using the concrete example of his own practice, the author explains the soundness of his opinion as regards dentist's chairs and cupboards (how to design them and what to put in them).

Dental Equipment↗
PubMed1985

Antipyretic effect and tolerability of suprofen suppositories. Controlled clinical double-blind study with placebo.

The aim of the present study was to investigate the antipyretic effect of alpha-methyl-4-(2-thienylcarbonyl)-phenyl acetic acid (suprofen, Suprol) 300 mg suppositories compared to placebo in patients with fever of various etiology. The trial was designed as a randomized double-blind study including 30 patients per treatment group. After insertion of the suppository, temperatures were measured after 30 min, 1, 2, 3, 31/2, 4, 5, and 6 h. The study was performed at four investigational centers. At the end of the study, a total of 61 patients could be evaluated: 27 on suprofen, 34 on placebo. There were no statistically significant differences in the anamnestic data. The mean age of the subjects on suprofen was 66.5 years, and on placebo 61.3 years. Prior to treatment, the mean temperatures in the two treatment groups were 38.8 and 38.9 degrees C, respectively. In the suprofen group, the temperature dropped to a mean of 37.9 degrees C within 3 h and to 37.6 degrees C within 6 h. The decrease in temperature was less marked in the placebo group; here the mean temperature was 38.4 degrees C after 3 h and 38.2 degrees C after 6 h. Suprofen was found to be superior to placebo throughout the study, the differences being statistically significant after 3 h up to 6 h. The only side effect experienced by a subject on suprofen was vomiting.

Aged↗
PubMed1984

A patient with testis seminoma, sarcoidosis, and neutropenic enterocolitis.

Seminoma and sarcoidosis do not seem to be associated diseases, judging from epidemiologic data. The presence of these two diseases in the patient whose case is reported may have been coincidental. It was observed, however, that when the testis tumor appeared in this patient, the longstanding sarcoid lesions significantly increased. The patient developed neutropenic enterocolitis after chemotherapy for a non-hematologic malignancy.

Adult↗
PubMed1983

Paradoxical release of LH under TRH dynamic test in patients suffering from "psychogenic" erective sexual impotency: lack of neuroradiological signs for hypophyseal lesions.

More than two thirds of the patients suffering from "psychogenic" erective sexual impotency display a paradoxical LH response to the injection of 200 micrograms of TRH. As it is known that similar responses exist in patients with gonadotropic cell adenomas, we undertook a tomographic examination of the sella turcica in 8 such patients. In none of the patients did the results favour the existence of a microadenoma. Though the hypothesis of an infra-radiological microadenoma cannot be excluded, it is highly plausible that the origin of the paradoxical response observed is a functional impairment of the hypothalamo-hypophyso-gonadal regulation.

Adenoma↗