Biomedical subjects

A H Omar

Publications and source records attributed to A H Omar.

At least 19 recordsLinked to original sources

PubMed1995

Studies on Chrysomyia albiceps (Wiedemann) one of the most important carrion flies in Egypt.

Chrysomyia albiceps often feeds to repletion and then regurgitates a portion of the food, a behaviour that heightens its importance as a mechanical vector of enteric pathogens. Pupae of this fly are susceptible to the attack of the parasitic wasp, Nasonia vitripennis in the laboratory as well as in nature at different underground depths where they pupate. The fly needs to feed on proteinaceous meals to start and complete its ovarian development. Liver, beef, camel, chicken, rabbit and fish meat were tested. Of the 6 tested diets, liver proved to be the most advantageous as 98% pupation was obtained, while with beef, camel, chicken, rabbit and fish 95.2%, 95.9%, 90.9%, 89.1% and 86% pupation, respectively, were obtained. Field observations revealed that Chrysomyia albiceps prefers to breed in big carcasses over small ones as the latter contain less moisture or amount of food and are subjected to desiccation and consumption before the full growth of larvae especially during the hot and dry months. Anatomical studies of the females attracted to a piece of meat in laboratory and outdoors experiments showed that the degree of ovarian development is variable including completely undeveloped ovaries, sexually mature ones and different stages of ovarian development. So, attraction to meat fulfill to important functions: nutrition and oviposition. Feeding visits are short in duration (6.2 +/- 2.1 min) and behaviourally simple. The oviposition visits last from 40-60 min with more complex behaviour which can be divided into the time before, during and after oviposition. Females in selecting a place for oviposition, preferred the softer places of the fresh meat; round its lower moist edge where much liquid food is present and where the females oviposit in groups at one location. When a female began to oviposit, it was joined by others that located the eggs with their ovipositors and started to oviposit where a clumped irregular egg masses are deposited.

Animals↗

PubMed1995

Cannibalism and predation behaviour of the blowfly, Chrysomyia albiceps (Wiedemann) larvae (Diptera: Calliphoridae).

Chrysomyia albiceps is considered as a carrion inhabitant and is essentially scavenger. It is among the first species to arrive at carrion and lays its eggs on it almost immediately under favourable conditions. Field studies in Giza area showed that although other flies arrive at the carrion shortly following Chrysomyia, as decomposition progresses, its larvae are the major component predominate, and the common fly emerging from carrion is its adults. First instar larvae is entirely necrophagous, but the 2nd and early 3rd instar larvae may be facultatively predaceous on other dipteran larvae (Muscina and Parasarcophaga) as an alternative food source under crowded or starved conditions. Cannibalism, second and early 3rd instars preying on the 1st instar larvae and on themselves has also been found. Considering the predation behaviour, C. albiceps may be considered as beneficial biological control agent to help in reducing populations of carrion flies which are of medical and veterinary importance owing to their significant role in causing the different kind of myiasis of man and animals. The second instar is less inclined than the early 3rd instar to serve as a predator. The numerous heavily sclerotized spines and fleshy processes of the robust and powerful preyer early 3rd instar larvae help in subduing the prey while their strong mouthhooks are used to penetrate the bodies of the other larvae for fluid extraction.

Animals↗

PubMed1994

Ease of handling and efficacy of Bricanyl Turbuhaler in Asian asthmatic children.

Ease of handling as well as efficacy of a new terbutaline inhalation device--Bricanyl Turbuhaler--were evaluated among eighty-six Asian children with mild to moderate asthma with a mean age of 8.7 years (range 5 to 14 years) in an open, non-comparative trial. Clinical evaluations were performed on four occasions, ie at the beginning of the run-in period, at the start of the study medication, after 2 weeks of treatment and after a total of 4 weeks of treatment. Appraisal of handling technique was performed by the investigator at the start and end of treatment. Peak expiratory flow rate (PEF) was determined at each visit. Diaries were also kept throughout this time; PEF and asthma symptom scores were recorded every morning and evening. Maximum scores for inhalation technique were achieved by 73% of patients after combined written and verbal instructions at the start of the study and 99% of patients achieved this score at the end of the 4 week treatment period with Bricanyl Turbuhaler. Assessment revealed that approximately 90% of the patients considered loading, inhalation and handling of the Turbuhaler device to be easy, and 90% considered it to be effective in affording symptom relief. Improvements in PEF and reductions in asthma symptoms were observed during the Bricanyl Turbuhaler treatment, as compared to baseline values. All patients tolerated the study medication well without any serious adverse events. We concluded that this group of Asian children were able to use this new "Turbuhaler" device of terbutaline without any difficulty.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Inhalation↗

PubMed1992

Effect of larval population density on dynamics of growth in Chrysomyia albiceps (Wiedemann). I. Effect of feeding behaviour and growth rate of larvae.

The feeding behaviour of uncrowded and crowded larvae differed as soon as feeding began. In case of high density populations, larvae tend to form dense clusters and this gregariousness is responsible for much of the injury and resulting predation. Larval growth rate had the same pattern up to 200 larvae per 20 grams meat, then this pattern greatly changed with the increase of densities. Larval survivorship remained high at densities up to 160 larvae per 20 gm meat, then decreased rapidly as larval density increased. The duration of larval development was extended and synchronization of larval pupal ecdysis was affected. Percentage of pupation and pupal weight were greatly decreased at high densities.

Animals↗

PubMed1992

Protein in the diet of male blowfly, Chrysomyia albiceps (Wiedemann).

Laboratory observation showed that males of blowfly, Chrysomyia albiceps (Wiedemann) attract to and feed on meat in adult breeding cages. Experiments under laboratory conditions of 27 +/- 3 degrees C and 60-70 R.H. showed that meat could replace water but could not replace sugar. Feeding on protein diet (meat) did not increase males longevity or their efficiency to mate with more than one female. Mating behaviour and duration of mating process did not also affected. Protein diet could not affect the percentage of egg hatching, percentage of pupation and percentage of adult emergence when the gravid virgin female were mated with protein fed males.

Animals↗

PubMed1992

Laboratory rearing of Wohlfahrtia nuba Wiedemann (Diptera-Sarcophagidae) in Egypt.

A colony of Wohlfahrtia nuba Wiedemann was set up in the laboratory starting from flies collected from Dier El Anba Shounouda from Sohag City. Procedures for successful establishment of a colony and laboratory maintenance of this fly are described. Duration of the whole larval and pupal stage under insectary and controlled conditions was studied. Effect of controlled temperatures 17, 27 and 32 degrees C on the duration of the three larval instars, the moulting process and mortality rate were also observed.

Animals↗

PubMed1991

Peak expiratory flow rate (PEFR) of Malaysian children.

Prediction equations for peak expiratory flow rate (PEFR) of Malay, Chinese and Indian children were obtained by analysing 1020 PEFR recordings of children free of respiratory symptoms and illnesses. Boys had significantly higher PEFR than girls. For both sexes the highest levels of PEFR were observed in Malays and the lowest in Indians. The differences between Malay and Chinese boys were not statistically significant but the levels of PEFR for Malay and Chinese boys were significantly higher than those for Indian boys. In girls the differences among the ethnic groups were not statistically significant. Although ethnic differences were observed in boys these differences might not be clinically important. A common prediction equation for each sex should be both practical and accurate. When compared with predicted levels for white American and Australian children the predicted levels of PEFR of Malaysian children were found to be lower; these differences could be clinically important and the use of standards for Western children when assessing Malaysian children might not be appropriate.

Body Height↗

PubMed1990

Respiratory symptoms and asthma in primary school children in Kuala Lumpur.

In a cross-sectional study of 7 to 12-year-old primary school children in Kuala Lumpur, the prevalence of chronic cough and/or phlegm, persistent wheeze, and doctor-diagnosed asthma were 8.0%, 8.0% and 8.7%, respectively. The prevalence of asthma (defined as persistent wheeze and/or doctor-diagnosed asthma) was 13.8%. 4.3% experienced at least one episode of chest illness that resulted in inactivity for at least 3 days in the previous year. The mean age of commencement of symptoms in the doctor-diagnosed asthma group was 2.75 years. The prevalence of chronic cough and/or phlegm and persistent wheeze were highest among Indian children (p less than 0.05). More Malays had been diagnosed as having asthma than the other ethnic groups but the differences were not statistically significant. The patients' fathers' low levels of education were associated with chronic cough and/or phlegm (p less than 0.05) but not with other complaints. Asthma was significantly more common among boys than girls. No age differences were noted. Further analysis showed that persistent wheeze and doctor-diagnosed asthma were associated with increased likelihood of other respiratory illnesses or doctor-diagnosed allergy before the age of 2 years.

Asthma↗

PubMed1989

Bronchiolitis obliterans in children--a report of six cases.

Six children who survived severe acute bronchiolitis in infancy and early childhood continued to have persistent symptoms of breathlessness, cough and wheeze resistant to bronchodilator therapy. Hyperinflation of the chest, widespread crepitations and rhonchi were persistent clinical features. Failure to thrive was a problem in most. At presentation clinical measles was diagnosed in one child and adenovirus titres were raised in another; the aetiological agents in the others were not known. Lung biopsy from the child with measles showed features of severe bronchiolitis. The clinical and radiological features and course of the illness were consistent with those of bronchiolitis obliterans. Although illness was prolonged the long term prognosis was satisfactory with the majority of children showing improved chest signs, growth and general health after four to eight years of follow up.

Acute Disease↗

PubMed1987