Actinomycosis: report of 21 cases. Experience of the Anatomy and Cytopathologic Pathology Laboratory of the Rabta Hospital

Actinomycosis is a chronic suppurative granulomatous disease caused by an anaerobic Gram positive germ, Actinomyces. From 1994 to 1999, 21 cases of actinomycosis have been diagnosed in our laboratory. The main localisations were cervicofacial and gynecologic the diagnosis relies on histopathologic examination that shows actinomycosic granules.     

Extrapulmonary tuberculosis in Tunisia. Report of 830 cases. Experience of the Anatomic Pathology Laboratory of the Rabta Hospital

We present the experience of pathological laboratory of la Rabta hospital in extra-pulmonary tuberculosis. We report an epidemiologic retrospective study of 830 cases occurring in our service over a period of 10 years from 1991 to 2000 and diagnosed by histopathological examination. Various epidemiological, clinical, pathological and diagnostic aspects are discussed.     

Contribution of the digestive tract microflora to amylomaize starch degradation in the rat.

To study in vivo the contribution of the bacterial flora to amylomaize starch degradation in the rat, germ-free and conventional rats were fed on a diet containing either a normal maize starch or an amylomaize starch. In germ-free rats maize starch was almost totally digested in the small intestine, whereas 40% of the ingested amylomaize starch reached the caecum and 30% was excreted, despite the very high endogenous amylase activity. Study by transmission electron microscopy of germ-free caecal contents showed an endocorrosion of the starch granule. In conventional rats, as in germ-free rats, digestibility of maize starch reached 98% in the small intestine, whereas that of amylomaize starch was only 60%. In the caecum of these rats amylomaize starch was fermented, and this led to a decrease in caecal pH and to formation of short-chain fatty acids (SCFA), especially propionate. Comparison between conventional rats fed on maize starch or amylomaize starch showed that caecal SCFA concentrations during a circadian cycle varied in the same way whereas total SCFA and lactic acid concentrations were much higher in rats fed on amylomaize starch. Amylase (EC 3.2.1.1) activity was similar in the caecal contents of conventional rats whatever the ingested starch. It was lower in conventional than in germ-free rats, but no starch granule remained in the caecum of conventional rats. These results showed that bacterial amylase was more efficient at degrading resistant amylomaize starch than endogenous amylase.     

Selective decontamination of the digestive tract in intensive care.

Nosocomial infection in intensive care unit (ICU) practice is a common problem and is associated with abnormal carriage of Gram-negative aerobic bacilli in the gastrointestinal tract, resulting in endogenous infections. Selective decontamination of the digestive tract (SDD) is a regimen aimed at preventing or eradicating this abnormal carriage. A large number of trials examining SDD in ICU practice have been published, the vast majority showing a significant reduction in the incidence of nosocomial, Gram-negative infection. However, the impact on morbidity and mortality is much less certain. A recent meta-analysis has suggested a 10-20% reduction in mortality (3-6% absolute difference) with SDD. A discussion of these results is presented together with potential criticisms of SDD.