Pattern of chromosomal abnormalities among referral casesin a tertiary health care facility in Riyadh, Sudi Arabia

To evaluate the cytogenetic findings among Saudi referred for suspected chromosomal anomalies that caused a variety of clinical disorders. Secondly, to estimate the frequency of chromosomal abnormalities in these patients and to compare our results with those reported in Saudi Arabia and elsewhere. Thirdly, to evaluate if there overuse by some clinicians who refer cases for cytogenetic study before exhausting other less expensive and time-consuming tests that may lead to the final diagnosis. Chromosomal analysis was performed on three hundreds and twenty five cases referred to the Cytogenetics Laboratory between June 2005 and May 2006 at King Fahad Medical City, Riyadh, Saudi Arabia [SA]. Indications for referrals for exclusion of chromosomal abnormalities was multiple congenital anomalies, dysmorphic features, unclassified mental retardation, developmental delay, primary amenorrhea, recurrent abortions and positive consanguinity. Data were collected from the referred patients' files. Lymphocyte culture was carried out according to standard procedures. Various types of chromosomal anomalies were recorded in 39 [12%] of the studied group of those, 35 [89.7%] showed numerical chromosomal abnormalities in the form of trisomy 21 [28; 71.7%]; trisomy 18 [2; 5.1%], trisomy 13 [2; 5.1%]; trisomy X [1; 2.5%] and monosomy 21 [2; 5.1%]. The remaining cases [4] showed structural chromosomal abnormalities in the form of dysmorphic features; 2 [5.1%]; mental retardation; 1 [2.5%] and Turner syndrome; 1 [2.5%]. Our results were compared to other studies results in SA and worldwide. Trisomy 21 was the most frequent chromosomal abnormality in this study. This study in addition to other similar studies in the same community figure out the chromosomal aberrations pattern in this area. It was concluded that awareness of the chromosomal aberrations frequencies will help clinicians working in Saudi Arabia and surrounding countries to determine the priority of requesting cytogenetic study in individual cases

Study of the preparation and characterization of copper ferrite including ferritization of copper scraps

Samples of copper ferrite, CuFe2O4, were prepared using both dry and wet processes, either from powders of iron oxide or from interaction of copper and iron sulfates, or co-precipitation of copper and iron hydroxides from homogeneous sulphate solutions at different pH values. Also, a sample of copper ferrite was prepared in optimum conditions from copper scraps. The effects of temperature and time of ferritization were studied. The prepared samples were investigated by X-ray diffraction analysis, differential thermal analysis, DTA, and scanning electron microscopy, SEM. Optimum conditions were found to depend on the input materials, the pH values, time and temperature

Ionic valency of vanadium or chromium and the enzymatic activity in Streptomyces caeruleus

The results of this investigation establish the fact that addition of 10-6 - 10-4 M chromium to the culture media, mostly stimulated the test intra-and extra-cellular enzymes of Streptomyces caeruleus. In most cases the hexavalent ion was more effective than the trivalent. Furthermore, Cr6+, was more inhibitory to dry weight gain than Cr3+. In the meantime, V2+ was mostly suppressive [except on Ac-P and GPT], whereas, V5+ was mostly stimulatory [endopeptidase being the exception]. The dry weight gain was slightly reduced by the former vanadium form and severely suppressed by the latter form. Accordingly, it seemed that the toxicity of these transitional elements was more apparent when supplemented in their high valency state accompanied by increased enzyme activity. The latter could be attenuated by lowering the valency of the cationic form of the ions

Use of the presence or absence of various enzymes to differentiate antibiotic producing Streptomyces

Six streptomyces species were differentiated on the basis of a number of enzymatic activities. Absence of LDH, alkaline phosphatase and CPK confirmed Streptomyces albovinaceus. The absence of GOT, alkaline phosphatase and LDH confirmed Streptomyces rimosus. Streptomyces recifensis can be characterized by the absence of GPT and GOT. All enzymes tested, except LDH, were detected in Strectomyces rubiginosus. Finally, the absence of CPK and presence of GPT confirms Strrptosgrcss rar;urloe. Detection of test enzymes except CPK and LDH denotes Streptomyces caeruleus

Valency [state of oxidation], a modulator for the toxicity of vanadium or chromium to streptomyces caeruleus

The results showed that the cationic form of either vanadium or chromium was less deleterious to dry weight gain by Streptomyces caeruleus than the anionic form. Whether cationic or anionic, chromium [at 10-4, 10-6 M] was more toxic than vanadium. The control samples almost completely hydrolyzed the starch content of the prevailing medium. V[V]+ or Cr[VI]+ induced the same hydrolyzing capacity when administered at their highest concentration but V[IV]+ or Cr[III]+ were less effective. Per unit biomass, 10-4 M of the four salts substantially increased the amount of hydrolyzed starch, V[V]+ and Cr[VI]+ were equally higher in efficacy than V[IV]+ and Cr[III]+. V[IV]+ at 10-6 - 10-5 M, remarkably increased the percentage utilization of starch in biomass yield. The same range of concentration of V[V]+ seemed without effect, whereas those of Cr[III]+ or Cr[VI]+ were almost equally suppressive. The antibiotic produced by S. caeruleus was highly potent against Erwinia carotovora var. Carotovora, Escherichia coli, Proteus vulgaris, Pseudomonas lachrymans, Bacillus subtilis, B. licheniformis, Mirococcus luteus. Addition of either forms of vanadium [at 10-6M] totally abolished the original antibiotic activity of the organism. The same level of Cr[VI]+ was less deleterious

Role of antibiosis in antagonism of streptomyces spp to soft rot bacteria in soil

In pot experiments, young melon seedlings were artificially infected with Erwinia carotovora var. carotovora under various conditions of amendment of Streptomyces venezuelae [S1], S. rubiginosus [S2] and S. recifensis [S3]. The three organisms were equally effective when appplied singly to the soil simultaneously with seed sowing. Their early application [one week before seed sowing] or spraying their broth before infection seemed less effective if not promoting pathogenecity. The mixed Streptomyces species were also potent [with few exceptions] when their spores were early prevailing in the soil before sowing or when their culture filtrates were sprayed on the seedlings before infection. The growth of melon plants drastically reduced the total bacterial count with lesser effect on the mycoflora. This was highly furthered in soils amended with the Streptomyces species on the day of seed sowing. Soil mycoflora was also drasticallt reduced when Streptomyces spores were amended to the soil before or accompanying melon seed sowing

Influence of vanadium salts on growth and antagonistic potentiality of three virulent plant pathogenic bacteria

vanadium, at 10-6 - 5 x 10-5 M, severely attenuated the rate of growth of Erwinia carotovora var. carotovora, Erwinia caroto-vora var. citrullis and Erwinia toxica; the penta-valent [vanadate] ion was more toxic than the tetravalent [vanadyl] form. Vanadate ion abolished the resistance of E. carotovora var. citrullis and Micrococcus luteus toward E. toxica filtrate; the resistance of E. carotovora var. carotovora, E. carotovora var. citrullis, E. toxica, Bacillus subtilis, Bacillus lichenoformis and Serratia marcescence toward E. carotovora var. citrullis broth and the resistance of E. toxica, Escherichia coli, E. subtilis and M. luteus against E. carotovora var. carotovora filtrate. Vanadyl ion broke the resistance of Proteus vulgaris, Bacillus cereus, Mycobacterium phlei and M. luteus to E. carotovora var. citrullis and that of E. carotovora var. carotovora, E. coli, B. subtilis, B. lichenoformis and M. phlei to E. carotovora var. carotovora toxins. Both forms of vanadium could break the resistance of E. toxica and E. carotovora var. citrullis to the antibiotics of Streptomyces venezuelae and S. rubiginosus whereas the vanadyl ion was able to do so for E. carotovora var. carotovora. Both forms of vanadium abolished the activity of S. reclfencis against both varieties of E. carotovora

Biological effects of methoprene on the larvae of cat flea ctenocephalides felis under different conditions

The present study was carried out to determine the effects of methoprene [IGR] on Florida cat flea strain, Ctenocephalides felis on some biological aspects, e.g. mortality, duration of larval and pupal stages and emergence of adults. These experiments were undertaken at both fluctuating outdoor conditions of temperature and relative humidity [16-35.5?C and 25-98% R.H.] and at constant low temperature [9?G] and mild R.H. [73%]. The present data indicated that the methoprene had hazardious effects on the pupation of larvae and adult emergence at outdoor conditions than at the controlled conditions of constant low temp. and mild R.H. The larval mortality increased with the increase of methoprene concentration at outdoor conditions only

effect of various atmospheric conditions on the development of two strains of xenopsylla cheopis in Egypt

The development of two strains of Xenopsylla cheopis one Northern [N] and one Southern [S] under variable temperatures and relative humidities was studied. The survival rate of eggs of both strains increased with the rise of relative humidity. The eggs and pupae of northern strain [N] tolerated a wide range of fluctuations of temperature and relative humidity than of southern strain [S]. The emergence rate of both strains Increased at high range of fluctuated R.H. The condition of 30-80% R.H and 15-28°C was more favouarble to pupae of the N than of the S strain. Nearly, similar findings were observed as regards the pupal duration

influence of host age on the survival and frequency of feeding of adults xenopsylla cheopis

It was noted that adult fleas survived longer when fed on baby mice at mild and high but not very high relative humidities. Similarly they required more blood meals when maintained on baby mice. The effect of relative humidity on the frequency of meals was stressed