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Biomedical subjects

H Marrakchi

Publications and source records attributed to H Marrakchi.

At least 19 recordsLinked to original sources

Successful pregnancies after using immotile spermatozoa from ejaculate, epididymis and testis.

OBJECTIVE: To assess the efficacy of intracytoplasmic sperm injection (ICSI) in term of pregnancy rate with immotile spermatozoa from ejaculate, epididymis and testis. STUDY DESIGN: A retrospective study was conducted between January 1998 and March 2001. We performed intracytoplasmic sperm injection with immotile spermatozoa, in 160 couples during 172 cycles. RESULTS: The birth rate per cycle was 38.4% in immotile spermatozoa from ejaculate, 35.4% from testis and 38.7% from epididymis. CONCLUSION: This retrospective analysis shows that immotile spermatozoa retrieved from epididymis or testicle gives similar fertilization and pregnancies rates as immotile spermatozoa from ejaculate.

Ejaculation↗

Mechanistic diversity and regulation of Type II fatty acid synthesis.

Fatty acid biosynthesis is catalysed in most bacteria by a group of highly conserved proteins known as the Type II fatty acid synthase (FAS) system. The Type II system organization is distinct from its mammalian counterpart and offers several unique sites for selective inhibition by antibacterial agents. There has been remarkable progress in the understanding of the genetics, biochemistry and regulation of Type II FASs. One important advance is the discovery of the interaction between the fatty acid degradation regulator, FadR, and the fatty acid biosynthesis regulator, FabR, in the transcriptional control of unsaturated fatty acid synthesis in Escherichia coli. The availability of genomic sequences and high-resolution protein crystal structures has expanded our understanding of Type II FASs beyond the E. coli model system to a number of pathogens. The molecular diversity among the pathway enzymes is illustrated by the discovery of a new type of enoyl-reductase in Streptococcus pneumoniae [enoyl-acyl carrier protein (ACP) reductase II, FabK], the presence of two enoyl-reductases in Bacillus subtilis (enoyl-ACP reductases I and III, FabI and FabL), and the use of a new mechanism for unsaturated fatty acid formation in S. pneumoniae ( trans -2- cis -3-enoyl-ACP isomerase, FabM). The solution structure of ACP from Mycobacterium tuberculosis revealed features common to all ACPs, but its extended C-terminal domain may reflect a specific interaction with very-long-chain intermediates.

Anti-Bacterial Agents↗

Immunologic determinants of disease evolution in localized cutaneous leishmaniasis due to Leishmania major.

Localized cutaneous leishmaniasis caused by Leishmania major is polymorphic in its clinical presentation and evolution. Clinical and parasitologic features and disease evolution of 112 Tunisian patients was evaluated. The expression of interleukin (IL)-4, IL-6, IL-10, IL-12 (p40), interferon (IFN)-gamma, and tumor necrosis factor (TNF)-alpha mRNA was analyzed by reverse transcription-polymerase chain reaction in 73 biopsies. Cytokine mRNA expression varied individually over a wide range; TNF-alpha, IL-6, and IFN-gamma were detectable in >90% of lesions, IL-12 and IL-10 in 40% and 70%, respectively, and IL-4 in only 9%. Statistical analysis demonstrated positive association between the level of IL-12 and IFN-gamma and the presence of parasites in the lesions. Unfavorable evolution of the lesions was positively associated with high IL-10, IL-12, and IFN-gamma mRNA expression. These results indicate that an unfavorable clinical outcome was not related to an inadequate Th1 cell response and suggest that the macrophage-activating effect of IFN-gamma may be inhibited by the concomitant expression of IL-10.

Animals↗

Structure of a hydroxymycolic acid potentially involved in the synthesis of oxygenated mycolic acids of the Mycobacterium tuberculosis complex.

Mycolic acids are believed to play a crucial role in the architecture of the mycobacterial envelope. However, very few steps of their biosynthetic pathway have yet been elucidated. We previously isolated [Dubnau, E., Lanéelle, M. A., Soares, S., Bénichou, A., Vaz, T., Promé, D., Promé, J. C., Daffé, M. & Quémard, A. (1997) Mycobacterium bovis BCG genes involved in the biosynthesis of cyclopropyl keto- and hydroxy-mycolic acids, Mol. Microbiol. 23, 313-322] a gene cluster from Mycobacterium bovis BCG, cmaA-D, which confers upon M. smegmatis the ability to synthesize cyclopropanated ketomycolic acid, and a new type of mycolic acid which is hydroxylated. A meticulous analysis of all the mycolic-like fatty acids of M. bovis BCG and M. tuberculosis showed that these organisms produce small amounts of the hydroxymycolic acid. The structure of this molecule, determined by NMR spectroscopy, mass spectrometry and stereochemical studies, strongly suggests that there is a direct biosynthetic relationship between the keto- and the hydroxy-mycolic acids.

Animals↗

Possible role of the V3 domain of gp120 in resistance to an amphotericin B derivative (MS8209) blocking human immunodeficiency virus entry.

MS8209, an amphotericin B derivative blocking human immunodeficiency virus type 1 (HIV-1) entry after CD4 binding, neutralized the HIV-2 strains EHO and ROD10 but not ROD(CEM). In the V3 domain of gp120, ROD(CEM) differed from ROD10 at two positions (a threonine instead of an isoleucine at position 312 and an arginine instead of a glutamine at position 329), and drug resistance was conferred to HIV-1 by substitution of the ROD(CEM) V3 but not the ROD10 V3. V3 mutations may prevent the interaction of gp120 with MS8209 or modify the mechanism of virus entry, rendering it less accessible to neutralization.

Amino Acid Sequence↗

[Spontaneous course of lesions of Leishmania major cutaneous leishmaniasis in Tunisia].

INTRODUCTION: The evolution of zoonotic cutaneous leishmaniasis (ZCL) caused by L. major, was usually described with crosssectional studies of patients under anti-leishmanial drugs. This work aimed to describe the clinical and parasitological status by a follow-up study of patients with ZCL and treated with a placebo. MATERIAL AND METHODS: In 1992, 58 patients with unique lesion of ZCL confirmed parasitologically and treated with vaseline twice a day for 15 days were followed in days 0, 15, 45 and 105. During every visit we have performed a clinical description of the lesion, a direct smear and a culture on NNN medium. RESULTS: 81 p. 100 of the lesions were ulcerated in day 0. A rapid clinical healing was noticed in 6.9 p. 100 of patients and the lesion remained active in 25.9 p. 100 of cases until day 105. Direct smears became negative among 56.4 p. 71 p. 100 and 92.3 p. 100 in days 15, 45 and 105 respectively. DISCUSSION: The ulcer was the most frequent sign during the diagnosis. The rapid conversion of positive parasitological tests suggest that the diagnosis of ZCL in endemic zones should be based mainly on clinical criteria.

Adolescent↗

[Kaposi's sarcoma and hypereosinophilic syndrome].

The authors report the case of a 73-year-old patient with severe Kaposi's sarcoma associated with an idiopathic hypereosinophilic syndrome. This association has not been reported until today and incites us to report this case.

Aged↗

[Tuberculosis of the upper digestive and respiratory tract].

Based on seventeen cases of upper digestive and respiratory tract tuberculosis, the authors review the different localizations of the disease. The mean age of the patients is 34 years old. The diagnostic is based on bacteriological and especially histological examination. The prognostic of the affection is excellent if tuberculosis chemotherapy is used for a minimum of 9 months.

Adult↗

[Malignant external otitis in diabetics].

The authors refer to 10 cases of malignant external otitis in diabetic patients. A group of five patients had a chirurgical treatment associated to an antibiotic therapy. The five other patients were treated medically. The prognosis of this disease is severe.

Aged↗