Updating the epidemiology of dermatophyte infections in Palestine with special reference to concomitant dermatophytosis.

OBJECTIVE: To determine the epidemiology of dermatophytosis in Palestinian patients, detect changes in the etiological agents during the last three decades, and to correlate between concomitant tinea pedis infections, and other cutaneous lesions. MATERIALS AND METHODS: 220 suspected dermatophytosis patients were involved in this study. In an additional 38 cases, where consultation was prompted by tinea pedis, the presence of other lesions of concomitant dermatophytosis was studied, to further investigate the diagnosis. Clinical specimens were collected and identification of dermatophyte species was based on gross and microscopic morphology. RESULTS: Epidemiology of tinea capitis has gone the most radical changes in Palestine in the last three decades, with the zoophilic dermatophyte Microsporum canis replacing Trichophyton violaceum, becoming the predominant causative agent. During this study, 21.6% (38/176) patients with tinea pedis and concomitant lesions caused by the same dermatophytes at sites distant from the primary lesions in the foot were prospectively identified. About 63.2% of patients with tinea pedis have a concomitant toenail onychomycosis infection. CONCLUSIONS: The epidemiology of dermatophytosis, especially tinea capitis, has gone the most radical changes in Palestine in the last three decades, with M. canis replacing T. violaceum, and becoming the predominant causative agent of all cases of infections. The coexistence of tinea pedis with other types of fungal skin infections is a frequent phenomenon; we believe that the infected foot may be a site of primary infection. Thus, the effective therapy for tinea pedis is essential to prevent spreading the infection to other sites of the skin.

Risk factors for nutritional rickets among children in Kuwait.

AIM: To assess the risk factors for nutritional rickets among children in Kuwait. METHODS: One hundred and three children with rickets and 102 control children matched for age and socioethnic characteristics were recruited over a 2 year period (January 1995 to January 1997) in Al-Adan Hospital in Kuwait. Diagnosis was made on clinical, radiologic and biochemical parameters. A specially designed questionnaire was administered by one of the investigators to both mothers of patients and mothers of control subjects to assess the role of social, nutritional and other related factors in the pathogenesis of nutritional rickets. Biochemical investigations included estimation of hemoglobin, serum calcium, serum phosphorus, serum alkaline phosphatase and serum 25-hydroxy vitamin D. RESULTS: The mean birthweights of rickets patients and control subjects were 3.20 +/- 0.46 and 3.19 +/- 0.45 kg, respectively. At the time of diagnosis, bodyweights of the patients and controls were 9.36 +/- 1.50 and 10.15 +/- 2.10 kg, respectively. Heights at the time of diagnosis were 73.58 and 77.24 cm for the patients and the controls, respectively. Mean hemoglobin, serum calcium and serum phosphate were significantly lower in the patients compared with the controls. Alkaline phosphatase was higher among the patients (P < 0.0001). The mean serum 25-hydroxy vitamin D level of the patients was 26.5 nmol/L, compared with 83.5 nmol/L in the controls. The mean age of starting semisolid feeds for the patients was 8.12 months, compared with 5.7 months in the controls. The nutritional quality of semisolid feeds was adequate among 71.6% of the controls as opposed to 13.6% of the patients. CONCLUSION: Nutritional rickets is a multifactorial condition. However, several factors seem to make important contributions. Among these, lack of exposure to sunlight, prolonged breast feeding without supplementation and inadequate weaning practices are important. Maternal education is important as it can influence all of the above factors.

Cellular distribution of HIV type 1 Nef protein: identification of domains in Nef required for association with membrane and detergent-insoluble cellular matrix.

Cellular distribution of HIV-1 Nef protein was studied by expressing the protein in mammalian cells. Cell extracts were fractionated by low- and high-speed centrifugation and by nonionic detergents. Two Nef-related proteins were expressed in COS cells, Nef-27kD and Nef-25kD. Nef-27kD, an N-myristoylated form of Nef, was found in the cytosol and in association with a particulate fraction of the cytoplasm. Treatment of the particulate cytoplasmic fraction with nonionic detergents, using three different protocols designed to isolate the cytoskeleton matrix, indicated that part of Nef was sensitive and part was resistant to detergent solubilization. These two cellular fractions represent membrane- and cytoskeleton-associated Nef. Nef-25kD, initiated from an in-frame AUG codon, was not modified with myristic acid at the amino terminus. Consequently, this protein was present in a soluble form in the cytosol. Furthermore, a mutant of Nef-27kD, in which the myristoylation signal is deleted, appears as a cytoplasmic soluble protein. To determine domains in Nef that are responsible for its subcellular distribution, successive internal deletions of 14-20 amino acids were introduced at the N-terminal portion of the protein. Five mutants were evaluated with respect to their cellular localization. One mutant (pSVLA-5), from which amino acids 73-88 were deleted, did not copurify with the detergent-insoluble fraction. The protein was, however, present in the particulate cytoplasmic fraction, presumably in association with membranes. Taken together, these results suggest that N-myristoylation of Nef affects its association with both membranes and cytoskeleton.(ABSTRACT TRUNCATED AT 250 WORDS)

cis Acting RNA sequences control the gag-pol translation readthrough in murine leukemia virus.

The pol gene of the Moloney murine leukemia virus (M-MuLV) is expressed as a Gag-Pol fusion protein through an in-frame suppression of the UAG termination codon located between the two genes. The role of nucleotide context in suppression was investigated, in a rabbit reticulocyte lysate translation system, using site-directed mutagenesis. The results indicate that the translational readthrough is mediated by at least 50 bases long RNA sequence located 3' to the gag UAG termination codon. Within this sequence a short purine-rich sequence adjacent to the amber codon, highly conserved among different retroviruses, appears essential for M-MuLV suppression. Two alternative putative stem and loop like RNA structures can be drawn at the gag-pol junction, one abutting the gag UAG codon, and the second downstream to it. None of these structures appears to be important to the suppression process.

Multimer resolution systems of ColE1 and ColK: localisation of the crossover site.

We have identified and characterised a stability function encoded by the high copy plasmid ColK. The function is analogous to ColE1 cer and maximises stability by maintaining plasmids in the monomeric state. In vivo recombination between cer and ckr (which share more than 90% homology at the DNA sequence level) produced a functional hybrid. Sequence analysis of hybrids indicates that recombination involving cer and ckr is site-specific and occurs within a 35 bp region of DNA which contains palindromic symmetry.

Lead encephalopathy in infants in Kuwait. A study of 20 infants with particular reference to clinical presentation and source of lead poisoning.

Twenty patients aged between one and eighteen months (mean six months) were found to have lead encephalopathy. They were seen in one 30-bed ward during a four year period from 1977 to 1980. Blood lead was determined in 19 children and ranged between 2.9 and 12.4 mumol/l (60 and 257 micrograms/dl) mean 5.42 mumol/l (113 micrograms/dl). Two patients died before starting treatment. Of the 18 patients treated with B.A.L. (2.3 dimercaptopropanol) and EDTA (ethylenediaminetetra-acetic acid), three died. Eleven patients made an apparently complete recovery and four had neurological sequelae. The source of lead was traced in 18 patients: in 11 it was due to the liberal use of Kohl (also known as surma) commonly used as an eye cosmetic in the Arabian peninsula. Other local sources of lead poisoning are discussed.