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Biomedical subjects

M K Hassan

Publications and source records attributed to M K Hassan.

15 recordsLinked to original sources
PubMed2006

Investigation of the mechanisms underlying the gastroprotective effect of nicorandil.

AIM: This study investigated possible mechanisms underlying the gastroprotective effect of nicorandil on experimentally-induced gastric lesions in rats. METHODS: Rats were randomly assigned to vehicle-, nicorandil (10 mg/kg)-, glibenclamide (6 mg/kg)-, nicorandil + glibenclamide- and cimetidine-pretreated groups, in addition to non-stressed control group, to demonstrate whether the K(ATP )channel opening contributed to nicorandil's gastroprotection. Lesions were induced by water immersion-restraint stress (WIRS) and ulcer indices were determined. Gastric juice parameters (pH, acid output, pepsin and mucin concentrations) were determined. Another set of rats was divided into control, saline-pretreated and nicorandil (10 mg/kg)-pretreated groups. Rats underwent WIRS and their stomachs were used for determination of gastric mucosal lipid peroxides, histamine, PGE(2), and total nitrites levels. RESULTS: Nicorandil displayed significant protection against gastric lesions formation, abolished by concomitant administration of glibenclamide. Nicorandil significantly reduced gastric acid and pepsin secretion, but upon coadministration with glibenclamide, these effects were blocked. Additionally, nicorandil significantly reduced gastric mucosal lipid peroxides and total nitrites, but did not affect PGE(2) and histamine levels. CONCLUSION: Results confirm a gastroprotective effect for nicorandil, the mechanism of which comprises K(ATP) channel opening, free radical scavenging, decrease of pepsin and acid secretion and prevention of the detrimental rise in nitric oxide during WIRS.

Animals↗
PubMed2004

Genetic resistance of Egyptian chickens to infectious bursal disease and Newcastle disease.

Genetic resistance of native Egyptian breeds to very virulent infectious bursal disease virus (vvIBDV) and Newcastle disease virus (NDV) was investigated in two experiments. In the first experiment, birds from four breeds (Gimmizah, Sina, Dandrawi and Mandarah) were challenged with vvIBDV. The Mandarah chickens had the lowest mortalities (10%) compared to the Gimmizah, Sina and Dandrawi chickens (55%, 35%, and 55%, respectively). Antibody response, lymphocyte response to mitogen, and bursal lesions did not clearly correlate with the mortality rates. In the second experiment, the four chicken breeds were challenged with virulent NDV. The Mandarah chickens re-emerged as a resistant breed (20%, mortality), while the Sina, Dandrawi and Gimmizah breeds were highly susceptible (85%, 100% and 100% mortality, respectively). Further studies on the resistance mechanism are warranted.

Animals↗
PubMed2004

Very virulent infectious bursal disease virus in Egypt: epidemiology, isolation and immunogenicity of classic vaccine.

Infectious bursal disease (IBD) is still a significant threat facing the Egyptian poultry industry. In this study, eight very virulent IBD viruses (vvIBDV), originating from acute IBD outbreaks recorded in lower and upper Egypt, were studied with respect to their ability to replicate in cell culture, antigenicity and immunogenicity of classic vaccine. Six continuous cell lines and one primary cell culture were tested for replication of the vvIBDVs. None of the vvIBDV isolates could be adapted to BGM-70, Vero, BHK, RK-13 or MDBK cell lines or chicken embryo fibroblast cells after six blind passages. Serological typing with three neutralizing monoclonal antibodies showed antigenic variation among vvIBDVs. The immunogenicity induced by graded doses of classic-intermediate vaccine in both IBD-resistant (Mandarah) and susceptible (Gimmizah) Egyptian chickens was investigated. The protection of the tested doses was evaluated by measurement of the serological response and resistance to vvIBDV challenge 10 days post vaccination. Similar antibody responses to the vaccine were generated over a wide (100-fold) dose range. It was concluded that single vaccination, by eye drops, with classic-intermediate vaccine (1 x) could protect chickens against clinical disease and mortality. However, the immune responses generated by 1 x, 10 x or 100 x vaccine doses did not protect against bursal damage following challenge. This finding points to the highly invasive nature of the prevailing vvIBDVs in Egypt.

Animals↗
PubMed2003

Obesity and health-related quality of life: a cross-sectional analysis of the US population.

OBJECTIVE: To examine the relationship between body mass index (BMI) and health-related quality-of-life (HRQL), in the presence of dietary controls and/or exercise in a national sample in the United States. METHODS: BMI and its association with HRQL domains (physical, mental and activity limitations) were examined using the Centers' for Disease Control and Prevention's 2000 Behavioral Risk Factor Surveillence System (BRFSS) data, after adjusting for various sociodemographic factors, self-reported health-status, and diet/exercise behavior. RESULTS: Based on World Health Organization's (WHO) classification of obesity, the study sample (N=182 372) included approximately 43.7% nonoverweight, 36% overweight, 14% obese, and 7% severely obese respondents. Exercise and dietary modifications were used by 17.5% of overweight, 15.2% of obese, and 12.5% of severely obese individuals. Logistic regression results using nonoverweight BMI as the reference category showed that severely obese (OR=1.87, 95% CI 1.64-2.12) and obese (OR=1.21, 95% CI 1.09-1.33) were more likely to experience greater than 14 unhealthy days affecting the physical health domain. Severely obese (OR=1.41, 95% CI 1.26-1.59) and obese (OR=1.17, 95% CI 1.07-1.28) were also more likely to experience greater than 14 unhealthy days affecting the mental health domain. Similarly, severely obese (OR=1.73, 95% CI 1.50-1.99) and obese (OR=1.22, 95% CI 1.08-1.37) were more likely to experience greater than 14 days with activity limitations. Exercise and dietary controls were associated with better HRQL across all three domains. CONCLUSION: The study highlights the relationship between BMI and HRQL in the United States. The study also underlines the positive correlation of exercise and dietary modifications with HRQL.

Analysis of Variance↗
PubMed2001

Transition from random to ordered fractals in fragmentation of particles in an open system.

We consider the fragmentation process with mass loss and discuss self-similar properties of the arising structure both in time and space, focusing on dimensional analysis. This exhibits a spectrum of mass exponents theta, whose exact numerical values are given for which x(-theta) or t(theta z) has the dimension of particle size distribution function psi(x,t), where z is the kinetic exponent. We obtained conditions for which the scaling and fragmentation process altogether breaks down, and we give an explicit scaling solution for a special case. Finally, we identify a new class of fractals ranging from random to nonrandom and show that the fractal dimension increases with increasing order and a transition to a strictly self-similar pattern occurs when randomness completely ceases.

Journal Article↗
PubMed2001

Risk factors for severe pneumonia in children in Basrah.

A case-control study was undertaken in Basrah Maternity and Children Hospital, Iraq. We studied 148 children who were admitted to hospital with severe pneumonia according to the World Health Organization (WHO) criteria and the controls were 250 children attending the out-patient department for non-severe respiratory infections. Significant risk factors were younger age (2-6 months), low parental education, smoking at home, prematurity, weaning from breast milk at < 6 months, a negative history of diphtheria, pertussis and tetanus vaccination, anaemia and malnutrition.

Case-Control Studies↗
PubMed1995

The development of an eluted stain bioassay (ESTA) for human growth hormone.

The basic characteristics of MTT-formazan production by both quiescent Nb2 cells and those activated by fetal calf serum or human growth hormone (hGH) are described. These characteristics are exploited for the development of an MTT-ESTA bioassay for purified preparations of lactogens such as growth hormone. The resulting in vitro bioassay is sensitive and precise, with a detection limit of about 0.05 mU hGH/l (19 ng/l) and a within-assay imprecision of 2.5% in the presence of 0.3 mU hGH/l (114 ng/l). When utilizing quiescent Nb2 cells for bioassays, large magnitudes of response are observed. The major component of the response is clearly derived from metabolic activation of the cells, rather than increased cell proliferation. The response was abolished by anti-human growth hormone. Delayed addition of the latter demonstrated that the presence of the hormone is required for the entire 96 h of the recommended bioassay incubation period to obtain the maximum response. At high doses, the dose-response relationship reaches a prolonged plateau which covers 4 orders of magnitude of incremental hormone concentrations. A decline in response is observed at the highest dose tested, 10(6) mU hGH/l (385 mg/l). This auto-inhibition is consistent with recent reports of a reduction in response due to stoichiometric blockade of sequential receptor dimerisation which is crucial for activation of both somatogenic and lactogenic receptors by hGH.

Animals↗
PubMedDate not supplied

Frequency of haemoglobinopathies and glucose-6-phosphate dehydrogenase deficiency in Basra.

Basra, southern Iraq, was mapped for haemoglobinopathies and glucose-6-phosphate dehydrogenase (G6PD) deficiency. Of 1064 couples aged 14-60 years recruited from the Public Health Laboratory, 49 had beta-thalassaemia trait, 69 had sickle-cell trait, 2 had haemoglobin D trait, 2 had haemoglobin C trait and 1 had high persistent fetal haemoglobin. Carriers of major beta-globin disorders comprised 11.48%. G6PD deficiency was detected in 133 individuals (12.5%). Only 10 couples (0.94%) were at risk of having children affected with either sickle-cell disease or beta-thalassaemia major. These defects constitute a real health problem and necessitate a management plan and public health education for early diagnosis and therapy.

Adolescent↗
PubMedDate not supplied

Prevalence of wheeze among preschool children in Basra governonate, southern Iraq.

A community-based survey was carried out in Basra governorate, Iraq, to estimate the prevalence of wheeze among children under 5 years old and to identify possible risk factors. It was found that 15.8% of the 424 preschool children enrolled in the study had a history of wheeze. More wheezy children lived in the city (16.3%) than in the rural area (15.0%). Family history of asthma in first-degree relatives was significantly associated with wheeze (44.8% of children with wheeze versus 15.1% without wheeze). Other household factors--parents' low educational level, formula or supplemental feeding as a baby, overcrowding, smoking at home, pet ownership and using kerosene--were associated with wheeze, but the results were not statistically significant. The role of environmental factors and feeding patterns needs to be further evaluated.

Animals↗
PubMedDate not supplied

Influence of the host system on the pathogenicity, immunogenicity, and antigenicity of infectious bursal disease virus.

The effect of the host system on the pathogenicity, immunogenicity, and antigenicity of infectious bursal disease virus (IBDV) was investigated. One classic (SAL) and one variant strain (IN) of IBDV were passaged separately six times in three host systems, namely BGM-70 continuous cell line, primary chicken embryo fibroblast (CEF) cells, or embryonating chicken eggs (embryos) or one time in the bursa of Fabricius (BF) of specific-pathogen-free (SPF) chickens. Passage in BGM-70 cells or CEF cells resulted in loss of pathogenicity, but viruses passaged in embryos or BF maintained their pathogenicity. For the immunogenicity study, the viruses described above were used to prepare live and inactivated vaccines, containing 10(3) mean embryo infectious doses (EID50s) and 10(5) EID50s respectively. These vaccines induced different levels of protection. It was concluded that the antigen titration methodology employing embryonating chicken eggs was not suitable for titration of viruses propagated in other host systems because of varying degrees of adaptation and/or pathogenicity of the viruses resulting in variability in antigen mass of the tested vaccines. To test this assumption, an antigen-capture enzyme-linked immunosorbent assay was used as a titration system to compare the antigenicity of viruses propagated in BGM-70 cells or BF. Preparations containing similar antigen masses were inactivated then inoculated into two age groups of SPF chickens and antibody titers were monitored. During the experimental period, the geometric mean virus-neutralizing (VN) antibody titers of the vaccinated groups did not differ significantly (P > 0.05).

Animals↗
PubMedDate not supplied

Comparison between antigen-capture ELISA and conventional methods used for titration of infectious bursal disease virus.

Two antigen-capture enzyme-linked immunosorbent assays (polyclonal and monoclonal AC-ELISAs) were developed and evaluated for titration of infectious bursal disease viruses (IBDVs) propagated in different host systems, namely BGM-70 continuous cell line, primary chicken embryo fibroblast cells, and chicken bursa of Fabricius. The polyclonal system was more sensitive (P < 0.05) than the monoclonal system but both were specific as indicated by the negative results obtained with three non-IBDVs. The results revealed that the conventional systems used for titration of IBDVs (cell cultures and embryonating chicken eggs) were more sensitive than the polyclonal AC-ELISA.

Animals↗
PubMedDate not supplied

Pathogenicity, attenuation, and immunogenicity of infectious bursal disease virus.

An investigation was conducted in specific-pathogen-free chickens on the pathogenicity of bursa-derived and tissue culture-attenuated classic (STC) and variant (IN) serotype 1 strains of infectious bursal disease virus. The IN bursa-derived virus caused bursal inflammation, necrosis, and atrophy earlier than the bursa-derived STC virus. Both viruses lost their pathogenicity after four passages in BGM-70 cells. A statistically significant level (P < 0.05) of protection was observed in SPF chickens vaccinated with the attenuated IN virus used as a live or inactivated vaccine followed by homologous (IN) and heterologous (STC) challenge with bursa-derived viruses.

Animals↗
PubMedDate not supplied

Antigenicity, pathogenicity, and immunogenicity of small and large plaque infectious bursal disease virus clones.

A serotype 1 variant strain of infectious bursal disease virus designated IN was passaged 40 times in BGM-70 cell line. A small plaque (SP) clone and a large plaque (LP) clone were then isolated and plaque purified four times. The SP and LP viruses formed circular plaques about 0.5 mm and 6.0 mm in diameter, respectively. Both clones lost their pathogenicity for specific-pathogen-free (SPF) chickens and did not elicit significant levels of virus-neutralizing antibody titers. However, the SP and LP clones maintained their immunogenicity when used as inactivated vaccines in SPF chickens. The restriction enzyme profiles of both clones were similar. Back passage of the SP and LP clones in SPF chickens resulted in loss of their phenotypic characteristics.

Animals↗