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Biomedical subjects

D Prigent

Publications and source records attributed to D Prigent.

At least 19 recordsLinked to original sources

[Role of vitamin deficiency in pancytopenia in Djibouti. Findings in a series of 81 consectutive patients].

The purpose of this study of patients with pancytopenia in Republic of Djibouti was to identify etiologic factors and attempt to define diagnostic and therapeutic strategies adapted to local conditions. Clinical, biological and radiological assessment was performed in 81 patients hospitalized for pancytopenia. There were 56 men and 25 women. Mean hemoglobin, leukocyte and platelet rates were 56,5 +/- 22,7 g/l, 2,1 +/- 0,7.g/l and 56,2 +/- 24,7 g/l respectively. Vitamin deficiency was the most common cause of pancytopenia (49%), followed by hypersplenism (9%), HIV infection (6%) and leishmaniasis (6%). Vitamin-deficient patients had significantly more severe anemia and thrombopenia and significantly higher mean corpuscular volume than patients with pancytopenia related to other causes. Hemoglobin rate lower than 40 g/L and platelet rate lower than 35 G/L showed a positive predictive values of 90% and 100% respectively for a vitamin deficient pancytopenia. Vitamin deficiency is the most frequent etiology of pancytopenia and causes the most severe cytopenia in Djibouti. Rapid vitamin supplementation after minimal etiologic assessment including a myelogram is an effective treatment strategy for this public health problem.

Adult↗

Outbreak of enterically-transmitted hepatitis due to hepatitis A and hepatitis E viruses.

BACKGROUND/AIMS: One hundred and eleven patients with acute hepatitis and 61 controls were investigated for hepatitis serological markers in order to determine the viral etiology of cases involved in a waterborne epidemic of hepatitis observed in 1993 in Djibouti, Republic of Djibouti (East Africa). These cases occurred both in indigenous Djiboutians, and in French soldiers and their families in Djibouti. A retrospective study of the viral etiology of acute hepatitis cases observed in French soldiers and relatives living in Djibouti during the 3-year period preceding the epidemic was also undertaken. METHODS: HAV, HBV and HCV infections were investigated using commercial ELISA tests. HEV infections were investigated by testing IgG and IgM-specific antibodies by means of three different ELISA tests using recombinant proteins or synthetic peptides. RESULTS: Hepatitis A was observed in 37 (33%) and hepatitis E in 43 (39%) of the 111 cases of acute hepatitis recorded during this epidemic. Hepatitis B represented only 6% of the indigenous cases and hepatitis C was not observed among the cases investigated. Anti-HEV IgG antibodies were also detected in 19% of the indigenous control group. CONCLUSION: These results suggest that both HAV and HEV were responsible for this waterborne epidemic of acute hepatitis. However, HAV and HEV infections were not equally distributed between French expatriates and Djibouti residents. Whereas HAV infections were mainly observed in French patients, HEV was almost exclusively found in indigenous patients. This study reports for the first time a waterborne outbreak of acute hepatitis simultaneously due to HAV and HEV.

Adolescent↗

[Epidemiologic aspects of 42 cases of human brucellosis in the Republic of Djibouti].

Brucellosis is an ubiquitous anthropozoonoses in the Republic of Djibouti, but it has only been studied in the City of Djibouti. This retrospective study of 42 cases of human brucellosis diagnosed between April 1993 and April 1995 was carried out at the Peltier Hospital in Djibouti to obtain epidemiological data concerning brucellosis in the Republic of Djibouti. Diagnosis was based on clinical symptoms and positive immunologic tests (Rose Bengal test > 100 UI and Wright serology > 1/80). The following information was obtained for each patient: nationality, ethnic origin, place of residence, age, sex, and risk factors for exposure to infected animals or products. There were 30 men and 12 women including 38 Djiboutis, 3 Somalis, and 1 Ethiopian. Ethnic origin was Afar in 32 cases, Somali in 6 cases, and undetermined in 4 cases. Mean age was 31.6 years. Of the 38 Djiboutis, 15 lived in the district of Djibouti, 17 in the district of Tadjourah, 3 in the district of Obock, and none in districts located in the Southern part of the country. In 18 cases brucellosis involved cattle raisers from the Northern part of the country. In five cases no risk factor could be identified. The incidence of brucellosis in the Republic of Djibouti appears to be comparable to that observed in other highly endemic countries. Further study is needed to determine the exact incidence in man and animals and ascertain the need and feasibility of preventive measures.

Adolescent↗

Proteoglycan degrading activity in granulomatous inflammation: comparison between the C57b1/6 and C57bg/bg mouse.

OBJECTIVE AND DESIGN: Proteoglycan (GAG) and collagen are lost from cartilage juxtaposed to murine granulomatous tissue in both control and C57bg/bg (elastase deficient mice). The objective was to extract and characterise proteoglycan degrading activity within granulomas of both strains. MATERIALS: 15 animals (female C57b1/6 and C57bg/bg mice) per group were used. TREATMENT: Cotton-wrapped rat femoral head cartilages were implanted subcutaneously into the dorsum of the mice and the granulomas excised fourteen days later. METHODS: Granuloma and granuloma cell-granule preparations were fractionated within a detergent-based buffer and tested for their abilities to degrade cartilage in vitro in the presence and absence of enzyme inhibitors. Elastase and cathepsin G activities were also assessed using specific substrates. Statistical significance was calculated using Student's t-test. RESULTS: Extracts from both strains induced the loss of cartilage GAG. This was correlated with cathepsin G activity (r = 0.96) and was inhibited by a specific cathepsin-G inhibitor (95%, p < 0.001), but not specific elastase or metalloproteinase inhibitors. Elastase activity but not that of cathepsin G was absent in the beige mice, whilst both enzymes were active in the controls. CONCLUSIONS: It appears that neutrophil cathepsin G may play an important role in the degradation of cartilage proteoglycan in the murine cotton-pellet granuloma in both C57b1/6 and C57bg/bg.

Animals↗

[Fulminant pneumococcal septicemia in a splenectomized child despite vaccination and chemoprophylaxis: necessity for education of the entourage].

A splenectomized three-year-old developed fulminant pneumococcal septicemia despite immunization and chemoprophylaxis. The course was rapidly fatal. Fulminant pneumococcal septicemia mainly affects splenectomized individuals and is associated with very substantial mortality. Immunization prior to splenectomy and daily prophylactic oral penicillin have partial preventive efficacy. Other useful measures include carrying a health status card and inpatient antimicrobial therapy in the event of fever. The need for these precautions should be repeatedly discussed with the child's parents and physician.

Bacteremia↗

Gelatinase is the main matrix metalloproteinase involved in granuloma-induced cartilage degradation.

This study was performed to characterize the matrix metalloproteinases (MMPs) produced during the degradation of cotton-wrapped cartilage, implanted into the murine air pouch. One, two or three weeks following cartilage implantation, proteins were extracted from the granulation tissue and MMP activities were measured. Although collagenase-, gelatinase- and stromelysin-like activities were detected at each time point, gelatinase activity was by far the most prominent. These enzymes were inhibited by EDTA, but not by NEM or PMSF, indicating that these proteinases were metalloproteinases. Gelatin zymography revealed several lysis zones amongst which a major 92-kDa band shifted to 83- and 68-kDa species during the course of implantation. The emergence of these species coincided with enhanced gelatinolytic activity and collagen loss from the implanted cartilage.

Animals↗

[Value and limits of tomodensitometry applied to the diagnosis of sacroiliitis in young adults: study of 200 cases].

Diagnosis of sacroiliitis may be difficult to establish in patients under 25 years of age since growth is not yet completed and joint damage is often still minor. A prospective study of 200 subjects with a median age of 22 years was carried out to compare the value of CT scan and conventional radiology. The study population included 32 healthy subjects and 168 consecutive patients with presumptive spondylarthropathy including 36 with bilateral sacroiliitis and 8 with unilateral sacroiliitis. Conventional roentgenograms and CT scans were performed in every patient. Blind reading of roentgenograms and CT scans was carried out by two pairs of observers with differing experience. CT scan provided no additional information when reading was done by experienced observers: rates of mistaken and doubtful results were similar with both investigations (10%); specificity of both tests was comparable (90%) but sensitivity was significantly greater for CT scan (91.2%) than for conventional roentgenograms (71.6%), reflecting improved detection of roentgenographically occult sacroiliitis. Less experienced observers obtained better results with CT scans, illustrating the ease of interpretation of CT scan images. Analysis of false-positive CT scans revealed that normal variations and, above all, features due to as yet uncompleted growth were the main sources of mistakes. These mistakes cancelled the advantage of increased sensitivity of CT scan studies and explained why CT scan failed to improve diagnosis.

Adult↗

Matrix metalloproteases are involved in granuloma-induced cartilage degradation.

The aim of this study was to test the role of matrix metalloproteases (MMP) in the in-vivo degradation of an implanted cartilage, using the modified mouse air-pouch model. Rat femoral-head cartilages were wrapped in cotton and implanted in 6-day-old mouse air-pouches. The mice were killed and the pouches opened 4, 7, 14 and 21 days after implantation. At each time the cartilages were removed and their contents of sulfated proteoglycan and collagen were determined. The collagenolytic activity of the pouch granulation tissue was measured, using a synthetic substrate. The implanted cartilage was found to be degraded, as previously described by Bottomley et al. (1988). The disappearance of proteoglycan and collagen began at days 4 and 7 respectively and increased progressively until day 21. An EDTA-inhibited collagenolytic activity was detected in the granulation tissue, and this increased from day 4 to day 21. These results demonstrate a progressive increase in the collagenolytic activity of the mouse air-pouch granulation tissue with a parallel loss of the matrix-macromolecules content of the implanted cartilage. The characterization of the metalloproteases involved is in progress.

Animals↗

[Treatment of reflex algoneurodystrophies by sympathetic blockade with guanethidine].

Reflex sympathetic dystrophy (RSD) can be treated by regional sympathetic blockade with guanethidine. This method was used systematically in 25 patients with post-traumatic RSD of the upper (n = 8) or lower limb (n = 17). Sixty three blocks were performed, each patient receiving 1 to 4 blocks. The results were appreciated by the effects after one month on pain, mobility and trophic changes. They were excellent in 7 cases, good in 4 cases and poor in 7 cases. The results were better in moderate RSD without psychiatric overlay. Thirteen patients were cured after 3 months. Pain decreased significantly 2 days after injection in 28 of the 63 blocks. The effects on mobility and trophic changes always occurred after the analgesic effect. No side effects were observed with the exception of one patient who had a convulsion 2 hours after the injection. These results show that regional sympathetic blockage with guanethidine is useful for the treatment of RSD, especially in its moderate stages. In view of the negligible risks and its efficacy, the authors consider it to be the first line treatment of moderate RSD.

Adult↗

[Articular manifestations of Behçet's disease. Apropos of 65 cases].

The authors, in a series of 65 cases of Behçet's disease, notice 53% of rheumatological manifestations which are third in line after aphthosis and ocular disease. In order of decreasing frequency, it concerns arthritis (mono, oligo or poly-arthritis), arthralgias with an almost identical frequency, sacroiliitis, extraarticular involvement. These rheumatological manifestations are readily associated with necrotic pseudo-folliculitis and cutaneous aphthosis.

Adolescent↗

Interaction of steptolysin O with sterols.

A quantitative study of the specific inhibitory power of cholesterol and other sterols on the hemolytic properties of streptolysin O is reported. This streptococcal exocellular protein is a cytolytic toxin which disrupts cytoplasmic membranes of eukaryote cells. The structural characteristics, particularly the stereochemical ones required for a steroid molecule to inhibit the cytolytic activity of streptolysin O, have been investigated in detail. By immunodiffusion techniques, in agar gel plates or tubes containing sterols, the formation of hydrophobic complexes between streptolysin O and inhibitory steroids, but not non-inhibitory steroids except lanosterol, is shown. Upon interaction with inhibitory steroids streptolysin O loses its immunoreactive properties towards neutralizing and precipitating homologous antibodies. An interpretation of the mechanism of biomembrane disorganization by streptolysin O is discussed in the light of its steroid binding properties.

Cholesterol↗