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Biomedical subjects

S A Mahmoud

Publications and source records attributed to S A Mahmoud.

At least 37 records · Page 2Linked to original sources
PubMed1978

Studies on the ovarian activity of the dromedary (Camelus dromedarius).

Post-ovulatory corpora haemorrhagica and mature corpora lutea were seen in the ovary of non pregnant dromedary only during the spring season. Regressed corpora lutea were noticed in the pvaries all-over the year together with many follicles of different sizes. 2 or 3 corpora lutea in different stages of regression might be found in the same ovary. Premordial follicles in the ovary of the dromedary were found to be distributed under tunica albuginea and extend deeply for a short distance in the cortical tissue. Number of these follicles are intact while others are atretic. The ovary of the dromedary shows very few number of intact growing follicles all-over the year. The majority of the growing follicles were found to show different stages of atresia. A large number of Graafian follicles is noticed in the ovaries of the dromedary examined all-over the year. Some of these Graafian follicles are intact, others show signs of atresia. The most common type of atresia that affects the large antral follicles is the cystic atresia. Both granulosa and theca cells of the dromedary undergo luteinization after ovulation to form the corpus luteum. This occurs earlier in the granulosa cells than in the theca cells. Regression of the corpus luteum was found to occur in the dromedary by 2 different ways, termed vascular and avascular types. Sometimes the 2 types of regression occur in the same ovary.

Animals↗
PubMed1978

A micromorphological study of the female copulatory organs of buffaloes in Egypt (Bos bubalus L.).

Samples from the different regions of the external genitalia of the Egyptian female buffalo, at different ages and different periods of the oestrus cycle, were examined microscopically after different strains. The walls of both vagina and its vestibule comprised mainly 3 coats; mucosa, musculosa and adventitia. The epithelia lining undergoes changes according to the period of the cycle. The circular muscle layer of vagina splits into 2 in the ventral wall and sandwitches in between a longitudinal layer and reunites oncemore in the dorsal wall. The lamina propria of the vestibula contains the following glandular structures: a) intraepithelial mucussecreting cells, b) large subepithelial glandular masses lying 1/2 cm caudal to hymen and extending for 3 cm caudally and 1 cm laterally in both dorsal and ventral walls, taking the form of compound tubuloaveolar muco-serous glands, and c) small glandular masses lying in the ventral median plane from the region of the fossa clitoridis and gradually disappearing cranially towards the suburethral diverticulum, taking the form of compound alveolar mucous glands. The clitoris is wholly formed of erectile tissue with smooth muscle fibers at its root and fat cells at its tip (glans). However, the latter cells were absent from calves.

Animals↗
PubMed1977

Studies on the rhizosphere and rhizoplane microflora of common-bean and barley.

Both broad bean and barley plants stimulated bacteria (total), N-fixing clostridia, Azotobacter ammonifiers, and aerobic cellulose-decomposers in their rhizosphere zone. The rhizosphere effects were generally positive until the 8th week of either plant growth. However, the rhizosphere effect differed according to type of plant, growth phase of each single plant, and type of micro-organism under study. The presence of high numbers of micro-organisms in the rhizoplane samples (washed ruptured roots) of each plant supports the evidence that roots of these plants are colonized with soil micro-organisms.

Azotobacter↗
PubMed1977

Studies on protein production by yeasts. III. Effects of different levels of nitrogen and phosphorus.

The four strains of yeasts that gave good growth in molasses medium, short generation time, and high protein content were selected for further studies in a trial for increasing their yield and protein content. Therefore, the effect of different levels of ammonium sulphate and potassium dihydrogen phosphate on the growth and protein synthesis of the strains was investigated, using molasses as a source of carbon. The results revealed that the most suitable concentrations of ammonium sulphate in the propagation medium lie between 0.40 to 0.55% for the production of high yield and protein content of strains S. cerevisiae (Gr. 104), C. utilis (F. 86), C. tropicalis (F. 35), and H. anomala (Gr. 5). The optimum concentration of potassium dihydrogen phosphate lies between 0.2 to 0.3% for the same strains. S. cerevisiae (Gr. 104) seemed to be the most efficient strain that gave the best growth, high percentage of protein, and essential amino acids in molasses medium.

Amino Acids↗
PubMed1977

Studies on protein production by yeasts. IV. Incremental feeding modulus.

S. cerevisiae Gr. 104 which seemed to be the most efficient strain in protein production, was used for investigating its optimum incremental feeding modulus that gives the highest economical yield. Therefore, different hourly rates of incremental feeding, ranging from 1.14 to 1.22, were used and the yeast yield for each rate was determined. Experiments were carried out in a laboratory fermentor vessel of 5 liter capacity, using molasses, ammonium sulphate, and potassium dihydrogen phosphate as feeding substances with optimum pH, temperature, and effective aeration. The optimum incremental feeding for this strain (which is the rate of molasses feeding corresponding to the exponential growth rate) was found to be 1.18. At this rate the best economical use of the substrate was obtained with the production of yield, close to the theoretically calculated yield.

Agriculture↗
PubMed1976

Studies on some nutritional factors influencing the production of gluconic acid.

Investigations were carried out to formulate an economical medium that can give maximum yield of gluconic acid by the submerged culture technique, using Aspergillus niger NRRL3. It was found that the highest yield of acid could be secured when a medium of the following ingredients was used: 13.0% glucose syrup, 0.1% NaNO3, 0.025% calcium superphosphate, 0.007% KCl, 0.025% MgSO4-7H20, and 0.5% CaCO3. It was also found that glucose syrup, which represents an available and cheap carbohydrate source for gluconic acid production by fermentation, can replace glucose powder which is more expensive.

Aspergillus↗