Biomedical subjects

A A el-Aaser

Publications and source records attributed to A A el-Aaser.

18 recordsLinked to original sources

PubMed1994

Effect of soybean, Vicia faba, and vitamin C on the carcinogenicity of DMBA.

A single dose of 10 mg of 7,12-dimethylbenz[a]anthracene (DMBA), administered to rats through intragastric intubation, was sufficient to induce many biochemical and histopathological changes in their mammary tissue. Significant increases were observed in the activity levels of the enzymes acid ribonuclease, 5-nucleotidase, alkaline phosphatase, and beta-glucuronidase in mammary tissue homogenates of DMBA-treated rats after an experimental period of five months. Histopathological studies of the mammary tissue also revealed malignant epithelial tumors (cribriform carcinoma) induced among 85% of the treated rats, with an incidence of 4 tumors in 12 mammary glands. Nevertheless, administration of 30% soybean in the diet of rats or 5,000 ppm ascorbic acid in their drinking water in addition to DMBA revealed a significant chemoprotective effect against the carcinogenesis induced by DMBA alone. This chemoprotective effect was demonstrated by the normalization of the activity levels of the enzymes studied in mammary tissue homogenates, because most of the enzymes were maintained at near the levels in the control animals. The incidence and number of tumors were also decreased. Cribriform carcinoma was observed in 50% of the rats, and the incidence of the affected glands was 2 in 12 mammary glands among both groups. On the other hand, a less chemoprotective effect was observed due to Vicia faba administration.

9,10-Dimethyl-1,2-benzanthracene↗

PubMed1994

Effect of Vicia faba and bran feeding on nitrosamine carcinogenesis and formation.

The goal of this work was to study the effect of the most common Egyptian food items, Vicia faba beans (VF) and bran, on the carcinogenicity of dibutylnitrosamine (DBN) precursors (dibutylamine and nitrite). Mice receiving DBN precursors showed a delayed gain in body weight as well as decreased protein level and 5-nucleotidase activity. Acid ribonuclease, alkaline phosphatase, and DNA level and rate of synthesis were significantly increased compared with corresponding controls. Hepatomas and bladder papillomas developed in 60% and 40% of mice, respectively, after nine months of treatment. On the other hand, administration of VF or bran, in addition to DBN precursors, lessened the damage caused by DBN precursors alone, except DNA level and rate of synthesis were elevated. Alkaline phosphatase was also elevated when bran was administered with DBN precursors. However, these elevations were still less than corresponding elevations in mice receiving DBN precursors alone. The incidence of hepatoma was also reduced to only 20% for both groups. Meanwhile, incidence of bladder papillomas was only 20% in mice receiving VF in addition to DBN precursors, and bladder papillomas were completely absent in mice receiving bran in addition to DBN precursors. In vitro studies were also performed to clarify the effect of VF or bran on diphenylnitrosamine (DPhNA) and its formation from its precursors (diphenylamine and nitrite). The study revealed that VF and bran have the ability to eliminate nitrite and DPhNA from the reaction media and to reduce the rate of formation of DPhNA from its precursors. This reaction depends on the concentration and form of VF or bran and the duration of the reaction. Thus it is concluded that some naturally occurring food items, such as VF and bran, could protect humans against the hazardous effect of nitrosamines and their precursors.

Animals↗

PubMed1989

Effects of soyabean and ascorbic acid on experimental carcinogenesis.

1. Ultrastructural changes in liver tissue of mice fed nitrosamine precursors, dibutylamine and nitrite, were observed. 2. The protective effect of soyabean in a diet containing nitrosamine precursors was demonstrated. 3. Liver tissue was examined to investigate the anticarcinogenicity of ascorbic acid. 4. The significance of soyabean and ascrobic acid in counteracting the potential hazards due to nitrosamine precursors is discussed.

Animals↗

PubMed1988

Effect of soybean feeding on experimental carcinogenesis--III. Carcinogenecity of nitrite and dibutylamine in mice: a histopathological study.

The potential carcinogenic effect of nitrosamine precursors, DBA (dibutylamine) and nitrite, was clearly demonstrated pathologically in the liver and bladder of male Swiss albino mice. Benign tumours were induced in the bladder with an incidence of 40%, and hepatomas were detected in the liver in 27% of the cases. The protective effect of soybean and ascorbic acid, added separately to the diet or to the drinking water respectively, was demonstrated by a marked reduction in dysplastic features and absence of tumour in both the liver and the urinary bladder.

Animals↗

PubMed1987

Frequency of active ras oncogenes in human bladder cancers associated with schistosomiasis.

The frequency of active ras oncogenes in human bladder cancers associated with schistosomiasis, the cause of which is suspected to be a chemical carcinogen(s) in urine, was examined. Of 9 squamous cell carcinomas of the bladder surgically obtained in Egypt, none scored as positive in the regular DNA transfection assay using NIH/3T3 cells as recipients. The restriction fragment length polymorphism assay at codon 12 of the H-ras gene confirmed the absence of an activating mutation at this site in all of them. Western blotting analysis of electrophoretic mobilities of the ras p21 proteins, a method which can detect at least some of the point mutations within codons 12 and 61 of ras genes, suggested a point mutation within codon 61 in one out of the 7 tumors analyzed. In contrast to the low frequency of detection of mutationally activated ras oncogenes, enhanced expression of the ras p21 proteins was demonstrated in 4 of them by this analysis. The carcinogenic process involved in the endemic bilharzial bladder cancers is thus not associated with detectable point mutations within ras genes at a higher frequency than those in non-bilharzial bladder cancers in Japan or the USA.

Animals↗

PubMed1987

Escherichia coli infection of the urinary bladder: induction of tumours in rats receiving nitrosamine precursors and augmentation of bladder carcinogenesis by N-nitrosobutyl (4-hydroxybutyl)amine.

Experimental introduction of Escherichia coli type 04 into the subserosa of the urinary bladder of female Fischer 344 rats produced chronic bacterial infection in more than 90% of animals. Groups of rats with bacterial infection were given sodium nitrate and either piperazine (Group 1) or dibutylamine (Group 2) in the drinking-water. Control, noninfected animals received nitrate and either piperazine (Group 3) or dibutylamine (Group 4). At 40 weeks, transitional-cell carcinomas of the bladder were detected in 9/30 rats in Group 1 compared to 0/34 in Group 3 (p less than 0.0005), and in 11/34 rats in Group 2 compared to 0/32 in Group 4 (p less than 0.0003). Early changes were examined by scanning and transmission electron microscopy as well as autoradiography. Preneoplastic liver foci were detected in infected groups of animals receiving amine and nitrate, indicating reabsorption of the carcinogen synthesized in situ to induce distant organ transformation. In another experiment, E. coli infection augmented bladder carcinogenesis by N-nitrosobutyl(4-hydroxybutyl)amine (NBHBA), as indicated by earlier appearance of bladder tumours (six weeks compared to nine weeks) and, after 25 weeks, higher incidences of transitional-cell carcinomas (41/46 compared to 39/53, p less than 0.05), squamous metaplasia (43% compared to 9%, p less than 0.0001), glandular metaplasia (26% compared to 13%, p less than 0.05) and muscle invasion (30% compared to 11%, p less than 0.01) in the E. coli-infected group receiving carcinogen compared to the noninfected group receiving carcinogen, respectively. These results indicate that bacterial infection of the urinary bladder may play a major role in bladder carcinogenesis, both by helping in-situ nitrosamine synthesis and by augmenting carcinogenesis by nitrosamines.

Amines↗

PubMed1986

Anal submucosal injection: a new route for drug administration in pelvic malignancies. Part I. Experimental study of misonidazole distribution in serum and tissues, with special reference to urinary bladder. Preliminary report.

The anal and oral administration routes were compared in 30 rats to study the distribution of misonidazole, a radiation sensitizer, in the serum and tissues with special reference to the urinary bladder. 14C-labelled misonidazole was administered in a dose of 0.2 ml water/100 gm body weight containing 1 mu Ci misonidazole. The dose was given orally by stomach tube in 15 rats, and was injected in the submucosa of the anal canal in another 15. Animals were then killed after 15, 30, 60, or 120 minutes or after 24 hours. Organs were dissected, and radioactivity was determined in each by the internal standard method. The study has shown that the highest drug concentration in the bladder tissue relative to the serum was achieved with the anal submucosal route. Its level was eight and five times that of the serum 15 and 30 minutes after administration, respectively, in contrast to the oral route in which the drug concentration was one-quarter and equal to the serum level at the same time intervals. The anal route would thus provide the adequate channel required for misonidazole to promote radiation responsiveness in bladder carcinoma.

Administration, Oral↗

PubMed1985

Serum estrogen level in Egyptian breast cancer patients.

In menstruating 20-29 year old breast cancer patients, the total estrogen level showed a significant increase in the early follicular phase compared to normal healthy subjects. Such a difference was not observed in 30-45 year-old patients. A nonsignificant decrease was observed in the estradiol level of premenopausal breast cancer patients compared to normal healthy subjects. However, in postmenopausal breast cancer patients, the total estrogen level as well as the estradiol level showed a significant increase compared to that of normal healthy subjects.

Adult↗

PubMed1984

Immunoglobulin A, G and E levels in Egyptians with cancer: influence of schistosomiasis.

The main patient series consisted of 415 Egyptians attending the Cairo Cancer Institute and comprising 286 bladder cancer, 97 breast cancer, 14 head and neck cancer and 18 gastrointestinal cancer cases. Also included in the study were 36 patients with active schistosomiasis and 89 health controls. Serum IgA, IgG, IgG subclasses, IgE, Schistosoma and Ascaris-specific IgE (RAST) and the acute-phase protein CRP were measured in all, or sub-sets, of the main patient group. The well-established increase in IgE and IgG levels, and the more recently reported increase in the levels of IgG3 and IgG4 subclasses in patients with schistosomiasis, were also found in bilharzial bladder cancer, indicating that humoral immunity persists in cancer-bearing patients. However, the plasma protein profile in bilharzial bladder cancer is further modified by significant increases in the levels of IgA, IgG, IgG1, IgG2 and CRP when compared to levels in patients with Bilharzia in the absence of neoplastic change. Patients with cancers not associated with parasitic infestation also had significant increases in their serum levels of IgG1, IgG2, IgG, IgE and CRP when compared to healthy Egyptian controls, but 41% of these non-bladder cancer patients showed IgE responses to previous parasitic infestations suggesting that any immunological response to cancer would be on the background of a variable non-specific increase of IgE.

Antibody Formation↗

PubMed1977

A direct lead technique for histochemical demonstration of leucocyte alkaline phosphatase activity in blood smears.

A histochemical technique for demonstrating leucocyte alkaline phosphatase activity (LAP), based on direct precipitation of lead phosphate at pH 9.5, is described. The effect of fixative, temperature and stability of the medium on the activity of the enzyme and stability of the colour reaction was thoroughly studied. Peripheral blood smears obtained from both normal humans and pathological cases were studied and the results were compared with these obtained by the azo-dye method.

Adult↗

PubMed1973