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Biomedical subjects

M David

Publications and source records attributed to M David.

At least 307 records · Page 17Linked to original sources
PubMed1994

[Rheumatic diseases and hemoglobinopathies in Lomé (Togo)].

This prospective cross-sectional study was designed to determine the frequency and impact of hemoglobinopathies in rheumatology clinic patients in Lomé (Togo). Among the 405 study patients, 142 (35%) had an abnormal hemoglobin, 22% had hemoglobin S, and 16.8% had hemoglobin C. Sickle cell anemia and sickle cell-hemoglobin C disease (2% and 4.2% of patients respectively) were associated with vasoocclusive crises and necrosis of the femoral head. Presence of AS or AC (heterozygotic forms of hemoglobins S and C) was found in 15.8% and 12.1% of patients, respectively. These proportions were similar to those reported in the population at large. Presence of AS or AC had no detectable influence on degenerative spinal disease, osteoarthritis of the knee, tendinitis or inflammatory joint diseases. Our data suggest that presence of AS or AC has no adverse significance and should be disregarded when evaluating patients with musculoskeletal symptoms.

Adolescent↗
PubMed1994

[Fathers in the delivery room--an East/West comparison].

The attendance of fathers in the delivery room to accompany the women giving birth is in Germany quite common. In this study we wanted to compare the results of a questionnaire on feelings, intention an anxiety of attending fathers in an east and west German maternity hospital. Although social acceptance of fathers in the delivery room in the eastern part of Germany is delayed by 10 years (compared to western clinics) the over all impression of attending fathers was similar. We aid find differences concerning the expectations, the way of mental preparing and considerations participating the approaching birth in east and west questionared fathers. The results also showed variable knowledge in respect of pregnancy and birth. We do think that after a time of ("father") experience in the east part of Germany the expression of opinion will adjust.

Adult↗
PubMed1994

[Mucocele of the appendix as a rare differential diagnosis of adnexa tumor].

It will be reported of a 68 year old woman, who underwent a laparotomy because of a tumor of the right ovary, which was ultrasonographically suspicious of being malign. During the operation, it was diagnosed as a mucocele of the appendix. It will be discussed, whether ultrasound is able to differentiate tumors of the lower right abdomen. Mechanisms of development and clinical signs of the mucocele of the appendix will also be described.

Aged↗
PubMed1994

[Carotid surgery without systematic preliminary angiography. 402 patients treated by surgery between 1986 and 1992].

Ultrasonography of the carotid bifurcation is a high performance technique for the detection of carotids stenosis. Associated with Doppler and echography, ultrasonography offers a means of precisely evaluating atheromatous stenoses of the bifurcation. The degree of narrowing can be calculated from the pulsed Doppler recordings and colour echo-Doppler measurements, reducing the subjective interpretation factor (the operator-dependent nature of the exploration is no longer related to data collection). Most severe stenoses can be diagnosed with these techniques. The question now is whether carotid angiography is still necessary to establish the indication for surgical endarterectomy. We attempted to give an answer based on our prospective series of 402 endarterectomies of the carotid bifurcation performed between 1986 and 1992 without prior routine angiography. Arteriography was performed occasionally in the pre-operative work-up but was limited to cases in which the ultrasonography was judged insufficient. We observed a mortality of 0.25% and a morbidity of 0.5%. This diagnostic approach is justified by its lower cost and reduced risk due to arteriography. In addition, unidentified arterial lesions downstream have little or no effect on indications and outcome.

Aged↗
PubMed1993

Comparative drug influence on peroxide mediated increase of cytosolic calcium in human endothelial cells.

The increase of cytosolic free calcium in human umbilical vein endothelial cells caused by peroxides was used as a model to determine and compare the putative cytoprotective properties of substances known to interfere with the generation or metabolism of reactive oxygen species. Hydrophilic hydrogen peroxide and lipophilic cumene hydroperoxide were used as sources of reactive oxygen. [Ca2+]i in endothelial cells was measured by the FURA method and the resting level was found to be 129.3 +/- 14.1 nM. Both peroxides were found to increase cytosolic calcium with dependence on the concentration and on the presence of extracellular calcium. Among the substances tested, only catalase and N-acetyl-cysteine were able to exhibit a significant cytoprotective effect.

Antioxidants↗
PubMed1993

Tyrosine phosphorylation of DNA binding proteins by multiple cytokines.

Interferon-alpha (IFN-alpha) and IFN-gamma regulate gene expression by tyrosine phosphorylation of several transcription factors that have the 91-kilodalton (p91) protein of interferon-stimulated gene factor-3 (ISGF-3) as a common component. Interferon-activated protein complexes bind enhancers present in the promoters of early response genes such as the high-affinity Fc gamma receptor gene (Fc gamma RI). Treatment of human peripheral blood monocytes or basophils with interleukin-3 (IL-3), IL-5, IL-10, or granulocyte-macrophage colony-stimulating factor (GM-CSF) activated DNA binding proteins that recognized the IFN-gamma response region (GRR) located in the promoter of the Fc gamma RI gene. Although tyrosine phosphorylation was required for the assembly of each of these GRR binding complexes, only those formed as a result of treatment with IFN-gamma or IL-10 contained p91. Instead, complexes activated by IL-3 or GM-CSF contained a tyrosine-phosphorylated protein of 80 kilodaltons. Induction of Fc gamma RI RNA occurred only with IFN-gamma and IL-10, whereas pretreatment of cells with GM-CSF or IL-3 inhibited IFN-gamma induction of Fc gamma RI RNA. Thus, several cytokines other than interferons can activate putative transcription factors by tyrosine phosphorylation.

Base Sequence↗
PubMed1993

The appearance of Kaposi sarcoma during corticosteroid therapy.

BACKGROUND: Four epidemiologic types of Kaposi sarcoma (KS) are known: classic KS, endemic African KS, epidemic or acquired immunodeficiency syndrome-related KS, and KS associated with immunosuppressive therapy. In most of the latter patients, KS was reported to have developed after organ transplantation, particularly renal transplantation. Thirty-nine patients who have not had a transplant have been reported to have KS associated with corticosteroid therapy. METHODS: The authors studied 10 patients with the appearance of KS during corticosteroid therapy (6 men, 4 women; age range, 42-79 years) who were treated with corticosteroids for autoimmune disorders (5 patients), lymphoproliferative disorders (2 patients), and diseases unrelated to the immune system (3 patients). RESULTS: Genetically programmed susceptibility to corticosteroid-related KS was suggested by the descent of the study patients as well as most of those reported previously. The prognosis was guarded in all the study patients. CONCLUSIONS: Corticosteroids should be withdrawn to achieve clinical remission.

Adult↗
PubMed1993

In vitro activation of the transcription factor ISGF3 by interferon alpha involves a membrane-associated tyrosine phosphatase and tyrosine kinase.

Interaction of interferon alpha (IFN alpha) with its cell surface receptor rapidly activates the formation of the transcription complex ISGF3, which subsequently translocates to the nucleus and stimulates the expression of a variety of early response genes. We have recently developed a cell-free system where IFN alpha can activate the formation of ISGF3 in vitro. This system has enabled us to demonstrate that the component of the ISGF3 transcription complex which is modified by IFN alpha treatment (ISGF3 alpha) is membrane-associated and that its activation involves a protein kinase. Using a combination of specific tyrosine kinase and phosphatase inhibitors and monoclonal anti-phosphotyrosine antibodies we now are able to demonstrate that IFN alpha-activated transcription involves at least a two-step process where a membrane-associated tyrosine phosphatase and a tyrosine kinase lead to modification of ISGF3 alpha and subsequent formation of the complete complex. Furthermore, formation of the ISGF3 complex is specifically disrupted by protein tyrosine phosphatase and can be reversibly dissociated by the phosphotyrosine analogue phenylphosphate. The latter observation suggested that SH2 and/or SH3 domains may be required for the stable formation of this transcription complex.

Base Sequence↗
PubMed1993

Effects of the antioxidant butylated hydroxyanisole on cytosolic free calcium concentration.

The effect of the antioxidant butylated hydroxyanisole on free intracellular calcium was investigated in rat cardiomyocytes, rat pituitary cells, human umbilical vein endothelial cells, granulocytes and BHK-cells. The effects of incubation time and butylated hydroxyanisole (BHA) concentrations were examined with respect to the extracellular calcium concentration. Butylated hydroxyanisole increased the free cytosolic calcium concentration in a dose- and time-dependent manner irrespective of the presence of extracellular calcium. Differences between all cell types were observed in the sequel of the re-uptake of the calcium ions released by BHA. Dependence on the concentration of extracellular calcium on the extent of sequestration was seen in rat pituitary cells and cardiomyocytes only.

Animals↗
PubMed1993

Dose-dependent induction or depression of cysteine conjugate beta-lyase in rat kidney by N-acetyl-S-(1,2,3,4,4-pentachloro-1,3-butadienyl)-L-cysteine.

The influence of N-acetyl-S-(1,2,3,4,4-pentachloro-1,3-butadienyl)-L-cysteine (NAc-PCBD) on cysteine conjugate beta-lyase in female rat kidney has been examined. After a single, non-nephrotoxic dose of NAc-PCBD (3 mg/kg), cytosolic beta-lyase enzyme activity was increased 1.5 to 3-fold commensurate with a corresponding increase in enzyme protein levels as assessed by both Western blot and ELISA analyses. Using a cDNA probe for beta-lyase, this induction was found to be accompanied by an increase in the cognate mRNA. In contrast, a higher, nephrotoxic dose of NAc-PCBD (10 mg/kg) decreased all the above parameters. These effects appeared to be specific to the cytosolic form of the enzyme as no changes in kidney mitochondrial beta-lyase or enzyme protein levels were observed. Repeated dosing with the lower dose level (3 mg/kg) resulted in either no change, or in some instances, a reduction in the above parameters, suggesting an accumulation of the xenobiotic and a masking of the induction phenomenon. The molecular mechanisms underlying these observations are discussed in terms of the nephrotoxicity of halogenated xenobiotics.

Acetylcysteine↗
PubMed1993

Sensory evaluation and nutrient composition of weaning food from pregelatinized maize-sweet potato mixtures.

Pregelatinized maize-sweet potato mix, fortified with soybeans and groundnut flours, was evaluated for its acceptability as a weaning food and for nutrient composition. An acceptable product had 14.3, 6.4, 2.4 and 67.4%, respectively, for its protein, fat, ash and carbohydrate contents. Values for calcium, phosphorus and and iron contents were 59.6, 187.5 and 2.4 mg/100 g, respectively, while the most predominant fatty acids were linoleic, oleic and palmitic acids. The product, which had a chemical score of 85.34 for its protein value, was limiting in threonine.

Calcium↗
PubMed1993

Quantitative and qualitative assessment of plasma von Willebrand factor in classic Kaposi's sarcoma.

BACKGROUND: von Willebrand factor (vWF) is synthesized almost exclusively by endothelial cells and is stored there as ultra-high-molecular-weight multimers. The vWF multimers that are detected in the plasma are smaller than those stored within the endothelium. In two previous studies, comprising small series of cases with classic Kaposi's sarcoma (KS), an endothelium-derived tumor, increased levels of plasma von Willebrand factor antigen (VWF:Ag, the antigenic structure) were reported, suggesting that vWF:Ag may be a marker of endothelium proliferation. OBJECTIVE: Our purpose was to investigate the quantitative as well as qualitative alterations of plasma vWF in a large series of patients with classic KS at various stages of the disease. METHODS: Levels of plasma vWF:Ag were studied in 38 patients with classic KS confined to the skin at various stages of the disease and compared with a control group. Thirty-three patients had active KS (i.e., with skin lesions) and five were in remission. In five patients with active KS multimeric analysis of plasma vWF was also performed. RESULTS: The levels of vWF:Ag were significantly higher among KS patients than in the control group (n = 29, p < 0.01). Levels of vWF:Ag were also significantly higher in patients with active disease as compared with those in remission (p < 0.05). No correlation was found between vWF:Ag levels and the extent of KS. Analysis of the multimeric pattern of plasma vWF showed enhanced staining of all bands, particularly the intermediate and high molecular weight forms, which resemble the endothelial forms as opposed to normal circulating vWF multimers. CONCLUSION: Quantitative as well as qualitative alterations in plasma vWF were found in patients with KS, which may reflect the destruction or activation of endothelial cells within the lesions. vWF:Ag may serve as a marker of disease activity in classic KS; however, it is not a good marker for the extent of the disease.

Aged↗
PubMed1993

Kaposi's sarcoma with visceral involvement after intraarticular and epidural injections of corticosteroids.

Kaposi's sarcoma has been reported in patients receiving immunosuppressive therapy, most of whom are organ transplant recipients. The development of Kaposi's sarcoma after treatment with corticosteroids has been reported in only 38 patients who have not had acquired immunodeficiency syndrome or undergone organ transplantation. Cutaneous Kaposi's sarcoma developed 2 months after intraarticular steroid injections in a man with ulnar nerve entrapment. The lesions regressed spontaneously after 3 months but reappeared with visceral involvement 18 months later, shortly after initiation of a course of epidural steroid injections for treatment of low back pain. The cutaneous lesions and some visceral lesions rapidly regressed after cessation of treatment.

Administration, Topical↗
PubMed1993

Prenatal diagnosis and treatment of 21-hydroxylase deficiency.

Prenatal diagnosis of 21-hydroxylase deficiency, the most common cause of congenital adrenal hyperplasia (CAH), has benefited from the advances in endocrinologic and molecular genetic studies. In 1976, prenatal diagnosis of the disease was first attempted by measuring 17-hydroxyprogesterone in the amniotic fluid in the second trimester of pregnancy. Discovery of a close linkage between HLA and the disease gave a second approach for prenatal diagnosis, the latter being made by linkage study of the haplotypes of the index case in a given family. Diagnosis was later made directly by molecular biology. Currently, the studies of the C4-CYP21B gene locus by Southern blotting and the CYP21B gene mutations by PCR methods simplify the diagnostic procedure of an early and accurate prenatal diagnosis in the first trimester. In these conditions all families are now informative. Moreover, using a direct genetic analysis associated with the possibility of detecting the heterozygotes in a non-related CAH population, a prenatal diagnosis can be done in a family without a previously CAH affected child. From our results in a series of 274 pregnancies at risk for CAH in whom prenatal diagnosis has been made by these different approaches, it can be concluded that steroid analysis in the amniotic fluid is an accurate method but provides only a late (second trimester) diagnosis, while an early and accurate diagnosis now relies on adequate molecular genetic studies on chorion villus biopsies. In the aim to prevent the virilization of the external genitalia in CAH female fetuses, prenatal treatment was instituted in our group in 1979 by giving dexamethasone to the mother. This prenatal treatment appears safe for the fetus and the child and is effective in preventing virilization of CAH affected females. Although the degree of prevention is not always complete in all cases, the advantages of prenatal treatment are prevailing over the complications observed in a few mothers.

Adrenal Hyperplasia, Congenital↗