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Biomedical subjects

A A Mustafa

Publications and source records attributed to A A Mustafa.

At least 37 records · Page 2Linked to original sources
PubMed1986

Evidence for the presence of histamine in Gaboon viper (Bitis gabonica) venom.

Venom from B. gabonica produced a dose-dependent contraction of both isolated guinea-pig ileum and rabbit aortic strip preparations. The venom-induced contraction was not antagonised by pretreatment with atropine, phentolamine, methysergide or indomethacin, however, it was blocked by the prior addition of chlorpheniramine or cyproheptadine. Upon exhaustive dialysis of the venom, the dialysate contracted both preparations, while the dialysed venom had no effect. Paper and thin-layer chromatography of the venom showed a spot with an Rf value corresponding to authentic histamine. Biological assay of the crude venom on the guinea-pig ileum showed that it contained the equivalent of 2-10 micrograms of histamine per mg dry weight of crude venom. pA2 values for chlorpheniramine using either the venom or histamine as agonists were not significantly different.

Animals↗
PubMed1986

Effects of Naja haje (Egyptian cobra), Naja naja (hooded cobra), Naja nigricollis (spitting cobra) and Naja mossambica mossambica (Mozambique spitting cobra) venoms on the isolated guinea-pig tracheal muscle.

Venoms from N. haje, N. naja, N. nigricollis and N. mossambica were tested on the isolated guinea-pig trachea. The four venoms (1-30 micrograms/ml) contracted the tracheal smooth muscle after a delay of 40-60 sec. A second challenge with the venoms caused either no or a much reduced contraction or a relaxant effect. The contraction could be prevented by pretreatment with antihistaminics, but not by atropine, methysergide or indomethacin, indicating that it is due to histamine release by the venoms. This release requires extracellular Ca2+, as it could be prevented by pretreatment with verapamil. Under conditions which prevented histamine release or its effect, each of the four venoms resulted in a reproducible relaxant effect which was not blocked by propranolol. It is concluded that the venoms have one or more component(s) causing histamine release which masks the relaxation caused by another component(s) of the venoms.

Animals↗
PubMed1986

Effect of venom from Bitis nasicornis (rhinoceros horned viper) on isolated rabbit aortic strips.

Venom from B. nasicornis, but not from Bitis arietans, Echis carinatus or Cerastes cerastes, produced an irreversible contraction of the isolated aortic strip that was slow in onset, increased with time, and reached maximum in about 10-15 min. The contraction was not inhibited by pretreatment with atropine, yohimbine, phentolamine, cyproheptadine or indomethacin, however, it was blocked by incubation in a Ca2+-free solution and was partially blocked by incubation with the Ca2+ channel blockers verapamil and nifedipine. It is concluded that B. nasicornis venom may act by increasing the Ca2+ influx into smooth cells, thus causing an increase in intracellular Ca2+ concentration and hence a contraction of the aortic strip.

Animals↗
PubMed1986

Neuromuscular blocking activity of a crude aqueous extract of Ipomoea fistulosa.

The rat phrenic nerve hemidiaphragm and chick biventer-cervicis preparations were used to investigate the effect of a crude aqueous extract of Ipomoea fistulosa. Electrically-induced skeletal muscle twitches of the hemidiaphragm were blocked by the extract and by tubocurarine. The anticholinesterase, physostigmine, intensified the blockade by the extract. The extract produced contracture of the chick biventer-cervicis preparation. It is suggested that the extract possesses neuromuscular blocking activity of a depolarizing nature.

Animals↗
PubMed1985

Effective dose equivalent and associated risks from mass chest radiography in Kuwait.

The number of x-ray examinations performed on persons undergoing mass chest radiography in Kuwait reached a maximum of 1.858 X 10(5) in 1982 with miniature radiography (70 mm) claiming more than 90% of the total number and the rest done with the large film technique. The annual prevalence of asymptomatic tuberculosis patients diagnosed by x rays, as reported by the project statistics, does not, in our opinion, justify exposing such a large population. In this paper, the effective dose equivalent is calculated from both miniature and large film mass chest radiography as applied in Kuwait. The values obtained are 283 mu Sv and 35.5 mu Sv, respectively. These figures yield calculated risks of fatal malignancies per examination of 3.37 X 10(-6) and 0.422 X 10(-6), respectively. The annual collective effective dose equivalent to the population undergoing mass chest radiography in Kuwait during the 7 y 1977-1983 is found to vary between 38-48 man-Sv. These figures are used to calculate an average of 0.5 additional cases of fatal malignancies per year, or about 12 excess fatalities in the forthcoming 25-y period if the number of mass chest x-ray examinations stays at its existing level. A total of 98% of these calculated excess fatalities result from the predominant technique, miniature radiography.

Adolescent↗
PubMed1985

Doses from occupational exposure: a study of radiation doses to workers in Kuwait over a four-year period.

The personal monitoring facility in the Ministry of Public Health's Radiation Protection Department has provided service to all users of ionizing radiation in medicine, research and industry in Kuwait. Exposure results during 1980-1983 were compared and analysed to examine the efficiency of protection measures adopted by each occupation. The results indicate that annual doses received by workers in different occupations in recent years tend to be generally low, but remain higher than those received by similar workers in other countries. Several overexposures to radiologists, radiology nurses, medical radiographers, and industrial radiographers increased the overall annual collective doses. As a result, protective measures designed for radiologists and nurses involved with special radiographical procedures should be improved. The recent use of the after-loading technique in intra-cavitary therapy was responsible for a significant reduction in the overall average doses received by workers involved in radiotherapy.

Film Dosimetry↗
PubMed1981

Small-angle multiple scattering and spatial resolution in charged particle tomography.

The formulae for the RMS scattering angle given by small-angle multiple-scattering theory are discussed and a correction to the standard Rossi formula is derived. Values of the correction factor are calculated for protons, alpha-particles and heavy ions; these results show that the correction is important for protons and alpha-particles but negligible for heavy ions with mass number 12-40. The values of the RMS scattering angle and the RMS lateral displacement are calculated for a proton beam passing through water. For protons the correction for energy loss in thick targets is even more important.

Alpha Particles↗
PubMed1980

Serological relationship between strains of Pasteurella multocida.

The serological inter-relationships of twenty four strains of Pasteurella multocida represented by 11 reference strains, each representing a different serogroup, and 13 strains from cattle with hemorrhagic septicemia were determined by agglutination and gel diffusion tests. There was agreement between the results of the two procedures indicating that both tests were probably employing the same antigen. Although all strains had strong serogroup-specific agglutinating and precipitating properties, they exhibited varying degrees of cross-reactivity. Strains M4, V A3 and Kobe 6 and strains R473 and 147 showed a close relationship with each other and might be regarded as having the same somatic antigen. Field isolates showed a distribution of reactions about the homologous titers of somatic groups 6, 7 and 8.

Agglutination Tests↗
PubMed1979

Biochemical and serological studies on Pasteurella multocida isolated from cattle in the Sudan.

Of 42 strains of Pasteurella meltocida isolated from different outbreaks of hemorrhagic septicaemia and from healthy cattle in various parts of the Suden, 38 belonged to Carters' type B and four to type E. The strain used for vaccine production was type E. With respect to somatic antigen determination, there was some correlation between the results of the gel diffusion and the agglutination tests as most strains reacted with 0 groups 6 antisera in both tests. However, some antigens cross-reacted with antisera of different 0 groups in the gel diffusion test. No correlation was observed between the pattern of biochemical reactions and the serological types.

Animals↗