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Biomedical subjects

M A Amer

Publications and source records attributed to M A Amer.

At least 19 recordsLinked to original sources
PubMed2005

Aflatoxin contamination of developing corn kernels.

Preharvest of corn and its contamination with aflatoxin is a serious problem. Some environmental and cultural factors responsible for infection and subsequent aflatoxin production were investigated in this study. Stage of growth and location of kernels on corn ears were found to be one of the important factors in the process of kernel infection with A. flavus & A. parasiticus. The results showed positive correlation between the stage of growth and kernel infection. Treatment of corn with aflatoxin reduced germination, protein and total nitrogen contents. Total and reducing soluble sugar was increase in corn kernels as response to infection. Sucrose and protein content were reduced in case of both pathogens. Shoot system length, seeding fresh weigh and seedling dry weigh was also affected. Both pathogens induced reduction of starch content. Healthy corn seedlings treated with aflatoxin solution were badly affected. Their leaves became yellow then, turned brown with further incubation. Moreover, their total chlorophyll and protein contents showed pronounced decrease. On the other hand, total phenolic compounds were increased. Histopathological studies indicated that A. flavus & A. parasiticus could colonize corn silks and invade developing kernels. Germination of A. flavus spores was occurred and hyphae spread rapidly across the silk, producing extensive growth and lateral branching. Conidiophores and conidia had formed in and on the corn silk. Temperature and relative humidity greatly influenced the growth of A. flavus & A. parasiticus and aflatoxin production.

Aflatoxins↗
PubMed2005

Reaction of selected soybean cultivars to Rhizoctonia root rot and other damping-off disease agents.

Eight soybean cultivars; Giza 21. Giza 22, Giza 35, Giza 82, Giza 83, Crawford, Holladay and Toamo were evaluated to Rhizoctonia root rot using agar plate and potted plant techniques. Data cleared that, in agar plate assay all soybean cultivars were moderately susceptible (MS), although the differences between them were significant (P=0.05). Generally, in potted assay, the reactions were resistant (R) or moderately resistant (MR) to root rots. Also, the differences between cultivars were significant (P=0.05). These cultivars were inoculated under greenhouse conditions with Fusarium solani, Macrophomina phaseolina, Rhizoctonia solani and Sclerotium rolfsii Generally, G21 had the least pre-emergence damping-off followed by Giza 35, Crawford and Giza 83 with averages of 19.0, 20.0, 20.5 and 21.5%, respectively. In case of post-emergence, Giza 35 had the least values, followed by Giza 21, Crawford and Giza 82 with averages 3.95, 4.10, 4.10 and 4.25%, respectively. Under naturally infested soil in the field conditions the reactions of the same cultivars to damping-off were evaluated in two successive seasons. In 2002 season, G35 had the least pre-emergence damping-off % followed by Giza 21 and Giza 22 with averages of 22.61, 24.33 and 29.33%, respectively. Also, G35 had the least post-emergence damping-off % followed by Toamo and Giza 21 with averages of 9.40, 10.33 and 10.41%, respectively. In 2003 season, the same trend was appeared with light grade where Giza 35 had the least pre-emergence damping of % followed by Giza 22 and Giza 21 with averages of 30.67, 31.00 and 36.67%, respectively and Giza 35 was the most resistant cultivar against post-emergence damping-off, followed by Giza 21 and Giza 22 with averages of 10.91, 11.32 and 11.80%, respectively. Generally, Giza 21 significantly surpassed the other cultivars in plant height, number of pods per plant and 100-seed weight. Moreover, also it had second grade with the other traits.

Colony Count, Microbial↗
PubMed2002

Modulation of age-related biochemical changes and oxidative stress by vitamin C and glutathione supplementation in old rats.

The present study sought to determine whether supplementation of dietary antioxidant ascorbic acid with glutathione (GSH) could ameliorate the age-related increased oxidative stress and changes in hormonal, lipid and copper (Cu) as well as zinc (Zn) levels in 18-month-old rats. The present study demonstrated that supplementation of vitamin C (30 mg) + GSH 100 mg/kg b.w. significantly reduced the concentration of thiobarbituric acid-reactive substances in liver and testes in old male rats as compared with nonsupplemented ones, indicating lower oxidative stress. In addition, testicular GSH was increased but not hepatic GSH. Also, cholesterol and triglycerides were decreased in the serum of supplemented rats. Furthermore, she serum testosterone level was increased in the same supplemented rats. However, the present results show that the thyroid hormones, T3 and T4, were not influenced. Lastly, the concentration of Cu in serum, liver, brain and testes was increased in supplemented old rats. Zn concentration was also increased in the same organs but not in the liver. According to the present study, the supplementation of antioxidants could play an important role in the modulation of the oxidative damage and changes associated with age.

Aging↗
PubMed2001

Attenuation of the acute adriamycin-induced cardiac and hepatic oxidative toxicity by N-(2-mercaptopropionyl) glycine in rats.

The protective effect of the synthetic aminothiol, N-(2-mercaptopropionyl) glycine (MPG) on adriamycin (ADR) induced acute cardiac and hepatic oxidative toxicity was evaluated in rats. ADR toxicity, induced by a single intraperitoneal injection (15 mg/kg), was indicated by an elevation in the level of serum glutamic pyruvic transaminase (GPT), glutamic oxaloacetic transaminase (GOT), creatine kinase isoenzyme (CK-MB), and lactic dehydrogenase (LDH). ADR produced significant elevation in thiobarbituric acid reactive substances (TBARS), indicating lipid peroxidation, and significantly inhibited the activity of superoxide dismutase (SOD) in heart and liver tissues. In contrast, a single injection of ADR did not affect the cardiac or hepatic glutathione (GSH) content and cardiac catalase (CAT) activity but elevated hepatic CAT. Pretreatment with MPG, (2.5 mg/kg) intragastrically, significantly reduced TBARS concentration in both heart and liver and ameliorated the inhibition of cardiac and hepatic SOD activity. In addition, MPG significantly decreased the serum level of GOT, GPT, CK-MB, and LDH of ADR treated rats. These results suggest that MPG exhibited antioxidative potentials that may protect heart and liver against ADR-induced acute oxidative toxicity. This protective effect might be mediated, at least in part, by the high redox potential of sulfhydryl groups that limit the activity of free radicals generated by ADR.

Alanine Transaminase↗
PubMed2001

Involvement of sex steroid hormones in the early stages of spermatogenesis in Japanese huchen (Hucho perryi ).

In higher vertebrates, considerable progress has been made in understanding the endocrine regulation of puberty; however, in teleosts, the regulatory mechanisms of spermatogenesis during the first annual cycle remain unclear. The present study was conducted to understand the regulatory mechanisms of spermatogenesis throughout the different stages of the first spermatogenic cycle and to check the ability of various steroids and hormones to induce in vitro spermatogonial proliferation in Japanese huchen (Hucho perryi ). The results indicate that the serum level of 11-ketotestosterone (11-KT) was positively associated with germ cell type; the level first began to rise with the appearance of late-type B spermatogonia and continued to increase gradually throughout the active spermatogenic stages and spermiogenesis, reaching a peak value 2 wk before spawning, and then declined. During the spermatogenic stages, the serum concentration of 17alpha,20beta-dihydroxy-4-pregnen-3-one (17alpha,20beta-DP) was undetectable. Only a small peak was detected with the appearance of spermatocytes and spermatids, and at the time of spawning, the level increased dramatically, reaching its maximum value with the onset of milt production. Despite the high variation in serum levels of 17beta-estradiol (E2) both between months and among the individuals, E2 was found during the whole reproductive cycle. From these results, we concluded that 1) 11-KT is necessary for the initiation of spermatogenesis and sperm production, and it probably plays a role in spermiation, 2) 17alpha,20beta-DP is essential for the final maturation stage, could play a significant role in the mitosis phase and meiosis process, and probably participates in the regulation of spawning behavior, and 3) estrogen is an indispensable male hormone that plays a physiological role in some aspects of testicular functions, especially during the mitotic phase. The three steroids were also able to induce DNA synthesis, spermatogonial renewal, and/or spermatogonial proliferation in vitro.

Animals↗
PubMed2001

The protective action of melatonin on indomethacin-induced gastric and testicular oxidative stress in rats.

Reactive oxygen species and lipid peroxidation play a role in the pathogenesis induced by the non-steroidal anti-inflammatory drug indomethacin. Melatonin (MLT) protection against indomethacin-induced oxidative tissue injury was investigated in gastric mucosa and testis of rats. MLT was administered intragastrically (i.g.) 30 min before the administration to fasted rats of 20 mg indomethacin/kg rat given i.g.. The area of gastric lesion as well as thiobarbituric acid reactive substances (TBARS) and lactate dehydrogenase (LDH) activity were found to be significantly increased 4 h after administration of indomethacin in rat gastric mucosa and testis indicating acute oxidative injury. MLT pretreatment reduced gastric lesion area to 80% of the indomethacin-treated rats and reduced the rise in TBARS concentration. MLT treatment reduced the LDH activity increase in testis but not in gastric mucosa. In indomethacin-treated rats, both the cytosolic Cu,Zn superoxide dismutase (Cu,Zn-SOD) and mitochondrial Mn-SOD activities were significantly diminished in gastric mucosa as well as the total SOD activity in testis. In addition, glutathione (GSH) content in both tissues was markedly decreased following indomethacin treatment. Pretreatment with MLT significantly ameliorated both the inhibition of SOD activity and the decreased GSH content in both tissues. Thus, these results show the effective antiperoxidative and preventive actions of MLT against indomethacin-induced gastric mucosal damage and testicular oxidative injury and we propose that this action might be relevant for its use with other free radical generating drugs.

Animals↗
PubMed1995

Assessment of inorganic lead species and total organo-alkyllead in some Egyptian agricultural soils.

This study was carried out to assess the amounts of (i) total Pb in soil, (ii) inorganic Pb species: exchangeable (EXCH), carbonate (CARB), easily reducible (EASR), moderately reducible (MODR), organic matter and sulfides (ORGS), and residual (RESD) bound Pb, and (iii) total organo-lead as alkyllead, in alluvial and lacustrine soils of the Nile delta, Egypt. Wide ranges of soil Pb were found in the alluvial (18.2-1850 microg g(-1)) and the lacustrine (39-1985 microg g(-1)) soils. The topsoil was highly enriched with Pb relative to the subsurface soils, especially in highly contaminated soils. There was no significant relationship between soil type and Pb content. Amounts of soil Pb greater than the background level (14 microg g(-1)) are due to Pb deposited from various anthropogenic activities. The partitioning of soil Pb into different species varied according to the intensity of contamination. It followed the sequence: RESD > ORGS > CARB > MODR > EASR in the slightly contaminated alluvial as well as lacustrine soils. In the highly contaminated soils, it followed the sequence: ORGS > MODR > CARB > EASR > RESD in the alluvial soils, and the sequence: ORGS > CARB > MODR > EASR > RESD in the lacustrine soils. There is high binding capacity of organic matter and sulfides to Pb, especially in the highly contaminated soils. The concentrations of total alkyllead in soils varied markedly and were related to both intensity of contamination and depth in the soil. The subsurface soil (15-30 cm) was highly enriched by alkyllead (means 224 and 353 ng g(-1) in the alluvial and lacustrine soils, respectively) relative to the surface and deeper soils. The proportion of total alkyllead as a percentage of total Pb in the soil was generally very low. It did not exceed 1.6% in the slightly contaminated soils, and 0.6% in the highly contaminated ones.

Journal Article↗
PubMed1993

Smectite in acute diarrhea in children: a double-blind placebo-controlled clinical trial.

Dioctahedral smectite (DS) a natural adsorbent clay capable of adsorbing viruses, bacteria, and other intestinal irritants in vitro, is claimed to possess beneficial "antidiarrheal" properties. This study tested the effect of DS on the duration of diarrhea and the frequency and amount of liquid stools. Ninety well-nourished boys, aged 3-24 months, with acute watery diarrhea and mild, moderate, or severe dehydration were included in a randomized double-blind, placebo-controlled trial. After initial rehydration, they received DS or placebo (1.5 g freshly dissolved in 50 ml of water, four times daily for 3 days) along with oral rehydration solution (ORS) and adequate feeding. The clinical characteristics of both groups were comparable on admission. Patients in the smectite group had a significantly shorter duration of diarrhea (mean +/- SD, 54 +/- 16 vs. 73 +/- 13 h) and significantly fewer stools (2.6 +/- 0.8 vs. 3 +/- 0.7 on second day; 1.9 +/- 0.7 vs. 2.4 +/- 0.7 on third day; and 11.3 +/- 3.2 vs. 13.8 +/- 3 overall). The amount of liquid stools was not significantly reduced. Weight gain at 24, 48, and 72 h and on recovery was significantly higher in the smectite group despite the comparable fluid and food intake in both groups. These results suggest a beneficial effect of DS in shortening the duration of diarrhea and reducing the frequency of liquid stools in children rehydrated with ORS.

Acute Disease↗
PubMed1993

Ultrastructure of Trichophyton violaceum.

BACKGROUND: The ultrastructure of different fungi have been described in recent literature; however, few reports have concerned dermatophytes. METHODS: Fine structure of Trichophyton violaceum was observed using electron microscopy. RESULTS: Hyphae appeared as branched segmented filaments with a cell wall consisting of two layers. Thin electron dense plasma membrane was evident continuous with the inner surface of the cell wall. Septal walls with central pores and a uniform electron opacity plugs were seen. The hyphae were multinucleated and the cytoplasm contained endoplasmic reticulum, mitochondria, and vacuoles. CONCLUSIONS: Although these findings showed ultrastructural similarities of the cell wall with Microsporum canis, Microsporum gypseum and Microsporum audouinii, there were some points of difference in the ultrastructure of the hyphae in Epidermophyton floccosum, and in the mitochondria of Trichophyton mentagrophytes as described by other investigators.

Microscopy, Electron↗
PubMed1992

Clinical and radiologic study of the frequency and presentation of chest infection in children with severe protein energy malnutrition.

The association between P.E.M. and frequent and severe life threatening infections including lower respiratory tract infections have been always reported. Lack of the usual general and local signs of infection in P.E.M. makes the diagnosis difficult and sometimes only postmortem. This study evaluated the frequency of chest infections as well as the sensitivity, specificity and predictivity of different signs and symptoms of the disease in 100 children with severe P.E.M. (marasmus, kwashiorkor, and marasmic kwashiorkor). Sixty two percent of the studied children had chest infection (33% pneumonia, 29% bronchitis). Although most patients were symptomatic, yet, signs and symptoms were few and mostly non specific. Chest roentgenograms are thus mandatory in evaluating patients with P.E.M. whenever possible. The only valuable signs suggestive of chest infection in P.E.M. were tachypnea (> or = 40/min) and/or chest indrawing. Both were moderately sensitive, highly specific and predictive of the disease particularly pneumonia. Their presence thus, its indicative of the need for early institution of antibiotic therapy even before the results of chest roentgenograms. Total Leucocytic count was of little diagnostic value while contrary to the common belief that tuberculin test is usually negative in P.E.M., the use of double the usual dose of P.P.D. (i.e. 10 TU) yielded positive reaction in some of the studied patients and thus must not be omitted from the routine investigations of malnourished patients.

Child Nutrition Disorders↗
PubMed1989

Anticholesteremic property of Lactobacillus acidophilus yogurt fed to mature boars.

Three strains of Lactobacilus acidophilus (LA) were isolated from the feces of mature boars that were not being fed antibiotics from the Nebraska Gene Pool (NGP). All three LA isolates were screened in vitro for anticholesteremic and antimicrobial activities. One strain, LA16, caused the greatest reduction in cholesterol and inhibited both Bacillus subtilis and Escherichia coli the most. LA16 was used to produce 16, 18.9-liter quantities of acidophilus yogurt (AY), over a period of 8 wk, for use as a feed ingredient in diets for the NGP boars. Colony forming units (cfu), pH, protein, energy, Ca and P were consistent across all 16 batches of yogurt. All of the 18 boars were fed a high-cholesterol diet for a period of 56 d at a rate of 2.268 kg/(hd.d) to furnish 6.661 g/(hd.d) of cholesterol. Nine of the boars then were fed 1.81 kg/(hd.d) of a second diet that was supplemented with .454 kg/(hd.d) of AY. The other nine boars were fed the original diet. Cholesterol intake was the same for the two dietary treatments. Blood samples were collected weekly from the brachial-jugular region and the sera were analyzed for lipids. Acidophilus yogurt reduced serum cholesterol (P less than .01) and low density lipoproteins (P less than .08), but it had no effect on serum triglycerides (P greater than .23) or on high density lipoproteins (P greater than .11).

Animal Feed↗
PubMed1987

Immunopotentiation.

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Adjuvants, Immunologic↗
PubMed1983

Clinical electrophysiologic assessment of ulnar nerve transposition in tuberculoid leprosy.

Ulnar nerve transposition was accomplished in 24 tuberculoid leprotic patients, making a total of 27 operations. Results were assessed clinically and electrophysiologically, pre- and postoperatively, and compared with a control group of 30 patients. Excellent results were obtained in early cases with minimal electromyographic changes. Late cases did not improve after surgery.

Adolescent↗
PubMed1983

Photochemotherapy and alopecia areata.

Four of ten patients with alopecia areata (plaque and totalis types) showed some regrowth of hair after PUVA therapy using a light box with peak emission 365 nm. Because PUVA may have long term side effects, this therapy should be reserved for patients resistant to other treatments.

Adolescent↗
PubMed1982

The effect of fermented and unfermented milks on serum cholesterol.

Groups of 10 to 13 healthy volunteers were provided with 11 supplements of 2% butterfat milk (2% milk), whole milk, skim milk, yogurt, buttermilk, and sweet acidophilus milk daily for a 3-wk period. Despite increases in caloric intakes on all supplements, no significant increases were found in total, low-density, and high-density lipoprotein cholesterol. A significant weight gain was seen in subjects taking yogurt and acidophilus groups; these were the only two groups showing significant rises in triglyceride levels. These results in normal volunteers focus attention on the current practice of recommending only skim or 2% milk for hyperlipidemic individuals.

Adolescent↗