[Celiac disease: special features in Africa. Description of 8 cases in Djibouti (horn of Africa)]

Celiac disease is poorly documented in intertropical Africa. The purpose of this retrospective report was to describe 8 cases observed at the Groupement Medico-Chirurgical of Bouffard Hospital in Djibouti (Horn of Africa) between January 2003 and January 2006. There were 5 females and 3 males ranging in age from 9 months to 17 years old (mean age: 48 months). Six patients were of Somali ethnic origin and two of Yemenite ethnic origin. Six were classified as middle class and 2 as lower class. All forms were symptomatic associating constant loss of weight with digestive manifestations (diarrhoea and vomiting). Diagnosis of celiac disease was based on the presence of anti-gliadin antibodies IgA and IgG associated with anti-endomysium or anti-transglutaminase antibodies that were measured in six and two cases respectively. Gastroduodenal endoscopy performed in three cases including two with duodenal biopsy demonstrated villous atrophy associated with gross of intra-epithelial lymphocytosis. A gluten-free diet initiated in five patients led to clinical improvement in four cases with a follow-up of 8.25 months. The findings of this study in Djibouti show that celiac disease exists in intertropical Africa. Its presentation is quite similar to elsewhere but diagnosis is more difficult due to poor knowledge about the disease and limited diagnostic facilities. Favourable response to presumptive treatment by a gluten-free diet is an alternative for diagnosis especially in Djibouti where eating habits differ from those in industrialized countries and this type of diet is easier to follow.

[Severe hypofibrinegenemia after rattlesnake envenomation in France]

A 22-year-old man, who maintains illegally numerous exotic snakes at home (suburbs of Paris), was bitten by one of his Bresilian rattlesnakes, the lance-headed viper Bothrops moojeni, with grade III envenomation. The fibrinogen was less than 0,5 g/L, the prothombin time was 22%, the activated partial thromboplastin time was 94 seconds. The authors discuss the biological and clinical management of this defibrination, due to defibrinogenating proteases (thrombin-like enzymes), present in Bothrops moojeni venom. The patient received 7 vials of an antivenom directed to another crotal, Bothrops lanceolatus. Despite the importance of defibrinogenation, there was only a few clinical evidence of bleeding, according to the literature. The normalization of coagulation studies occured only after day 11. This case-report outlines the danger of the increase of exotic snakes maintained as pet in France and the difficulties to obtain specific antivenoms.

[Recovery method of serotypable character in non serotypable pseudomonas aeruginosa strains]

Serotyping is one of the most used techniques for typing Pseudomonas aeruginosa strains. During chronic infections, and especially in cystic fibrosis, the decrease of lipopolysaccharide production is responsible for difficulties in determining O antigens. The possibility of serotyping can be simply restored by using a primary culture broth containing amikacin (1/6 of the strain MIC for this antibiotic); this is due to the ability of this antibiotic to inhibit alginate production. This technique allowed us to determine the serotype of 108 non-serotypable strains of P. aeruginosa isolated in 14 different hospitals. Among these isolates, serotype O:1 and O:13, had a high prevalence; the origin is a deficiency in D-glucose and L-rhamnose, required for the synthesis of lipopolysaccharide. In contrast, these sugars are not present in lipopolysaccharide of O:12, and these strains are always serotypable. The main protein is Alg C; this bifunctional enzyme is required in the exopolysaccharide and lipopolysaccharide production, according stress conditions in the bacterial-cells' environment. Determination of the serotype, as Antibiogram, is essential for genotypic inquiries.

[Value of non-esterified fatty acids quantification in diabetes]

Non-esterified fatty acids (NEFA) play a complex role in glucidic homeostasis. This role led us to investigate their quantification in diabetic patients. The plasmatic NEFA concentrations, measured with the FA115 kit of Randox, showed significant differences between control patients (0.42 +/- 0.14 mmol/L, N = 50) and diabetic patients (0.68 +/- 0.35 mmol/L, p < 0.01, 443 diabetic patients (70 with type l and 373 with type 2 diabetes)). NEFA concentrations were significantly higher in type 2 diabetics (0.70 +/- 0.32 mmol/L) when compared to type 1 diabetics (0.59 +/- 0.35 mmol/L, p < 0.05). In type 2 diabetics, a significant correlation was observed between NEFA and glucose concentrations at 8 hrs a.m., and the mean glucose concentrations along the day (p < 0.001). In contrast NEFA concentrations were less correlated to levels of HbA1c. NEFA were well correlated with cholesterol and triglycerides (p < 0.05) but not with Lp(a). They were also correlated with BMI but not with age or duration of the disease. Diabetic patients on metformin associated to lipolytic treatment, presented lower concentrations of NEFA and better glucidic control. The results confirm the role of NEFA in glucidic homeostasis and suggest an interest for their routine determination.

[Drug interference with the determination of urinary proteins with pyrocatechol violet Upro Vitros slides]

The purpose of this study is to investigate drug's interference on proteinuria's determination with pyorcatechol violet (Vitros technology). Five drugs were selected: gelatin based vascular replacement fluids (Plasmion), deferoxamine (Desféral), ceftriaxone (Rocéphine), ceftazidime (Fortum) and imipeneme (Tienam). To state precisely the role played by slide's technology, a liquid phase dosage was simultaneously made with pyrocatechol violet. No interference was notified with therapeutical range for four of them: gelatin, deferoxamine, ceftazidime and imipeneme. Slides technology prevents from gelatin's interference because the colorant is sensible to this drugs. On the other hand, positive interference was observed with ceftriaxone for urinary concentration upper than 0.75 g/L. This concentration is lower than that notified by Vitros laboratory in the technical data.

[Direct determination or estimated value of plasma ionized calcium : indications and limits]

Calcium plays a fundamental role in many essential for life functions. Ionized calcium (Ca(++) ) represents free fraction and 50% of the total calcium in the plasma is accepted as its physiologically active form. On almost all laboratories, only total calcium is routinely measured, and ionized calcium concentration is calculated based on calcium, protein or albumin concentrations for many plasma sample or with others parameters like pH. Since 1935, the literature was abounted with "correction" formulae of varying degree of sophistication. Many laboratories routinely use correction formulae to either calculate an "adjusted" or "corrected" total calcium, or "ionized" fraction is calculated,but these determinations lack of accuracy or precision. Errors associated with the measurement of the other variables contribuate to the difficulty in producing a useful correction formulae. Direct measurement of ionized calcium by potentiometry is the method of choice for this assay. Improvements in ion selective electrodes (ISE) technology make possible the routine clinical measurement of Ca(++). However this technology implies several obligations for its use, particulary in blood ampling, storage and transport. In this review, characteristics of different available analysers are described. We think that Ca(++) should be systematically performed and not calculated in pathological situations where an possible alteration of the calcium metabolism is found especially in multiple myeloma in which paraprotein may bind calcium.

[Methemalbuminnemia after massive hemolysis during blackwater fever]

We report a case of blackwater fever with brown plasma due to the presence of methemalbumin. The discovery of plasma with this color is a rare event at the laboratory. This compound appears during intravascular hemolysis or hemorrhagic pancreatitis when the ability of haptoglobin and hemopexin to bind free hemoglobin has been exceeded. In these cases some of heme is oxidized to hematin and taken up by serum albumin to form an albumin-hematin complex called methemalbumin. The major clinical problem is to evoke the diagnosis of methemalbuminemia and not confuse with methemoglobinemia. In our case, methemalbumin was detected and quantified using a scanning spectrophotometer. Its diagnostic and clinicals consequences are discussed.

[Biological monitoring of chronic hemodialysis]

Patients suffering from acute renal failure must undergo dialysis to substitute for the kidney's excretory function. Dialysis is a means of exchange between two solutions: blood and a liquid known as dialysate, across a semi-permeable membrane. This membrane permits the passage of water and aqueous solutions of low molecular weight but not that of the aqueous solutions of high molecular weight such as proteins. Dialysed patients are biologically monitored to prevent the various complications arising from blood dialysis, to check the efficacy of the treatment as well as to reduce the risk of morbidity and mortality. Because of the multiple and complex nature of renal functions, biological monitoring of a dialysis patients presents many, often inter-related facets. In addition to the complications inherent in dialysis itself, the dialysed patient is exposed to other causes of mortality or morbidity such as nutritional, hematologic, cardiovascular and infectious problems. Clinicians is confronted by other complications, albeit less common and easier to control, in the form of osteoarticular troubles or even aluminium poisoning. Lastly, biological assessment of the efficacy of purifying processing depends principally on calculating the dose of dialysate and the ureic index of subtraction which, in turn, requires the measurement of uremia.

Decreased virulence of a strain of Pseudomonas aeruginosa O12 overexpressing a chromosomal type 1 beta-lactamase could be due to reduced expression of cell-to-cell signaling dependent virulence factors

Pseudomonas aeruginosa produces a large variety of virulence factors and is characterized by its capacity to rapidly develop resistance when exposed to antibiotics. In order to evaluate a possible correlation between acquired resistance to antibiotics and virulence, we examined the virulence of four isogenic variants of P. aeruginosa O12 that differ in their resistance phenotypes to various beta-lactam antibiotics in a mouse model of acute pneumonia. Strains overproducing a chromosomal type 1 beta-lactamase were less virulent in both immunocompetent and immunosuppressed animals. Whereas the production of the exopolysaccharide alginate was similar between the four strains, extracellular virulence factors (elastase, rhamnolipid) that are controlled by the cell-to-cell signaling system circuit were detected in reduced amounts in the supernatant of the two isolates overproducing type 1 beta-lactamase. These results suggest that strains overexpressing the chromosomal type 1 beta-lactamase could be less virulent because of a reduction of cell-to-cell signaling dependent virulence factor production.