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Biomedical subjects

A Ismail

Publications and source records attributed to A Ismail.

At least 91 records · Page 5Linked to original sources

Antibacterial and antiviral activity of camel milk protective proteins.

Lysozyme (LZ), lactoferrin (LF), lactoperoxidase (LP), immunoglobulin G and secretory immunoglobulin A were extracted from camel milk. The activity of these protective proteins was assayed against Lactococcus lactis subsp. cremoris, Escherichia coli, Staphylococcus aureus, Salmonella typhimurium and rotavirus. Comparative activities of egg white LZ, bovine LZ and bovine LF are also presented. The antibacterial activity spectrum of camel milk LZ was similar to that of egg white LZ, and differed from bovine milk LZ. Bovine and camel milk LF antibacterial activity spectra were similar. The camel milk LP was bacteriostatic against the Gram-positive strains and was bactericidal against Gram-negative cultures. The immunoglobulins had little effect against the bacteria but high titres of antibodies against rotavirus were found in camel milk. The LP system was ineffective against rotavirus.

Animals↗

Demonstration of an antigenic protein specific for Salmonella typhi.

Current studies were undertaken to determine the presence of a specific antigenic protein on the outer membrane of Salmonella typhi. Immunoblot analysis using sera from patients with fevers revealed that the 50 kD band was specifically recognized only by typhoid sera. The 50 kD band located on the outer membrane is protein by nature and is not a Vi (capsular), dH (flagellar), or O9 (somatic) antigen of S. typhi. These results indicate the usefulness of the specific antigen in the development of a serodiagnostic test for typhoid fever since antibodies of both the IgM and IgG class responses were obtained.

Antigens, Bacterial↗

Protection against alcohol-induced gastric mucosal injury by nitecapone.

1. The mechanism of gastric mucosal protection by an anticular agent, nitecapone, against injury was investigated in rats with and without indomethacin pretreatment. 2. Animals received intragastrically either a dose of nitecapone or vehicle alone, followed by ethanol given at various intervals up to 5 hr, and their gastric mucosa subjected to histologic and physicochemical assessment. 3. Ethanol caused extensive gastric hemorrhagic lesions which were essentially prevented by nitecapone at doses of 30 mg and higher per kg body weight. The maximal protection was achieved by 1.5 hr which persisted up to 4 hr and was not thwarted by indomethacin. 4. Physicochemical measurements revealed that nitecapone evoked 78% increase in mucus gel dimension, and showed 21% increase in phospholipids, and the content of sulfo-(22%) and sialomucins (72%). This was accompanied by 1.6-fold increase in mucus viscosity, 31% increase in H+ retardation capacity and 2.2-fold increase in hydrophobicity. 5. The results suggest that the gastroprotective action of nitecapone occurs through the enhancement of the physicochemical characteristics of mucus layer.

Animals↗

GM1 ganglioside protection against ethanol-induced gastric mucosal injury.

The gastroprotective properties of GM1-ganglioside, an indigenous component of epithelial cell membrane, was investigated. The experiments were conducted with groups of rats with and without indomethacin pretreatment. The animals received intragastrically either a dose of GM1 as emulsion in 5% gum arabic or vehicle alone, followed by ethanol given at various time intervals up to 3 h after the GM1. The animals were sacrificed 30 min after the ethanol dose and their gastric mucosa subjected to macroscopic and histologic assessment, and physicochemical measurements. In the absence of GM1, ethanol caused extensive gastric hemorrhagic lesions which were significantly reduced by pretreatment with GM1 at dose as low as 70 micrograms/100 g body weight. Removal of sialic acid from GM1 led to the loss of gastroprotection. Furthermore, the effect of GM1 was not thwarted by indomethacin. The maximal protection was achieved 1 h following GM1 dose and this protective effect persisted at least 2.5 hr. The results of physicochemical measurements revealed that GM1 was capable of preventing the detrimental effect of indomethacin on the adherent mucus gel dimension, and on its content of sulfo- and sialomucins, protein, and phospholipids. The effects brought by GM1 were also accompanied by a significant (40-60%) increase in mucus gel viscosity, hydrogen ion retardation capacity (35-46%) and hydrophobicity (70-94%). The results indicate that the gastroprotective action of GM1 occurs through the enhancement of the physicochemical characteristics of the mucus layer, and does not appear to be mediated by endogenous prostaglandins.

Animals↗

Dot enzyme immunosorbent assay for the serodiagnosis of typhoid fever.

A nitrocellulose membrane strip dotted with a specific 50 kDa outer membrane protein of Salmonella typhi was applied for the serodiagnosis of typhoid fever. Using horseradish peroxidase conjugated IgM and IgG antibodies with 4-chloronaphthol as substrate, antibodies in typhoid patients were clearly visualised as bluish purple dots while sera from patients with non-typhoid fevers gave negative results. The detection of specific IgM and IgG antibodies in typhoid patients suggest either recent or current infection. Combined with the high specificity, reliability and rapidity of the test, the dot EIA technique provides a simple and useful method for the serodiagnosis of typhoid using a single serum specimen.

Enzyme-Linked Immunosorbent Assay↗

Placement and replacement of restorations in a military population.

The purpose of this study was to investigate the reasons for placement and replacement of restorations provided to military personnel by all 34 dentists stationed in the four Atlantic provinces of Canada. All dentists who participated in this study are salaried. Over a period of 30 working days, each dentist recorded information on all restorations performed. Data were collected on dentists' year of graduation, patient age, treatment requirements, tooth number, restoration class, materials used and reasons for placement and replacement. All dentists used the same data collection form which was pilot tested. Information was collected on 2,280 restorations from 643 adults, 18 to 57 years of age. Of all restorations, 54.3% were placements and 45.7% were replacements. No difference in placement and replacement rates between amalgam and composites was reported. The major reason for placement was primary caries (90%). The major reasons for replacements were recurrent caries (40.0%), primary caries of interproximal surfaces (18.9%), and fractured restorations (12.3%). Of the 297 MOD restorations, 74.3% were replacements and of the 1,140 Class I + III + V restorations, 27.8% were replacements. This study showed that about half of the restorative work carried out were replacements. Caries is the primary reason for placement and replacement of restorations in adults.

Canada↗

Evaluation of the GO Slide, a growth transport system for the laboratory diagnosis of gonorrhoea.

A growth transport system, the GO Slide (Roche Diagnostica), for the isolation of Neisseria gonorrhoeae from clinical specimens was evaluated. This system was compared with culture on chocolate agar (CA) and modified Thayer-Martin (MTM) agar, and Gram-stained smear for the diagnosis of gonorrhoea. Of 94 urethral specimens from symptomatic males, 77.7% were positive on MTM, 80.9% were positive on CA and Gram stain, and 81.9% were positive on GO Slide. Of the 77 isolates, 26.0% were penicillinase producers, 12.3% belonged to WI serogroup and 87.7% belonged to WII/III serogroup. The ease of transportation and the easy examination of growth on agar surfaces make the GO Slide an attractive system. It would be particularly useful for general practitioners without culture facilities to transport specimens to the laboratory for the isolation of N. gonorrhoeae.

Culture Media↗

The young pregnant teenager--why the poor outcome?

Studies have repeatedly emphasised the poor obstetric outcome in teenage pregnancies. This study examined 444 teenagers of 16 years and under and demonstrated little difference in the outcome between 14 years and under group and 15 to 16 year old. The poor pregnancy outcome, however, was predominantly related to the adequacy of antenatal care. The discussion emphasises the point that teenage pregnancy is not primarily a medical problem and much effort is required to create an awareness so that prenatal care is both accessible and acceptable to the pregnant teenager.

Adolescent↗

Siderophore production by Salmonella typhi.

This study was initiated to determine the mechanism of iron-uptake in Salmonella typhi. When stressed for iron, microorganisms produce siderophores to obtain the necessary nutrient. Generally two types of siderophores exist: the phenolate-type predominantly produced by bacteria and the hydroxamate-type commonly secreted by fungi. Results of this investigation showed that S. typhi produced siderophores of the phenolate-type since culture supernatant of the organism grown under iron-deprivation supported the growth of the phenolate-dependent auxotroph. The culture supernatant when extracted for phenolate siderophores, also supported the growth of the phenolate auxotroph but not the hydroxamate auxotroph. Production of phenolate-type siderophores were further confirmed using biochemical assays. These results showed that S. typhi utilized the high-affinity iron transport system to obtain the necessary iron.

Arthrobacter↗

An update on diarrhoeal diseases in Malaysia.

Analysis of diarrhoeal disease patterns in Malaysia from 1981-1986 suggested that infectious hepatitis ranked as the most predominant diarrhoeal disease followed by typhoid, food poisoning, dysentery and cholera. Although these five major food and water-borne diseases are still endemic in this country, diarrhoeal diseases per se no longer become an important public health problem in Malaysia. Enforcement of the cholera control program brought the incidence of the disease to a minimal. Unfortunately, this fatal form of diarrhoeal disease caused the greatest mortality compared to the others. Seasonal influence also played a part in controlling the occurrence of the disease. There was a preponderance of diarrhoeal diseases during the rainy season implicating contaminated water as a source of transmission. Although greater than half of the population has been supplied with piped water and sanitary latrines, a lot more has to be done before diarrhoeal diseases could be eliminated from this country.

Child, Preschool↗

Penicillin-sensitive spectinomycin-resistant Neisseria gonorrhoeae.

The first identification in Australia of a penicillin-sensitive spectinomycin-resistant Neisseria gonorrhoeae organism is reported. The method of identification is detailed. Caution is recommended in the use of spectinomycin for the primary treatment of gonorrhoea.

Adult↗

Clinical and immunological results of segmental splenectomy in schistosomiasis.

We evaluated segmental splenectomy in 51 patients who required splenectomy to relieve the symptoms of schistosomal splenomegaly, and compared their course with that of 44 patients who underwent total splenectomy in an unrandomized study. We describe a minor modification of our initial technique. Patients having segmental splenectomy had a similar postoperative course to those having total splenectomy. Conversion of a segmental to a total splenectomy was required in two cases due to technical faults. No regrowth of the spleen has occurred in up to 4 years of observation. We noted an increased percentage of T lymphocytes with an increased ratio of T helper to T suppressor cells in patients having segmental splenectomy. Our cumulative experience supports adoption and wider evaluation of segmental splenectomy in schistosomiasis.

Adolescent↗

Utilization of siderophores by Candida albicans.

Candida albicans secretes both hydroxamate and phenolate-type siderophores when grown under iron-restricted conditions. The inhibition of candidal growth by iron limitation was reversed by the addition of supplemental hydroxamate on phenolate siderophores. Both siderophores produced equal stimulation of growth suggesting that C. albicans could utilize both siderophores with equal efficiency. Addition of heterologous siderophores from both bacteria and fungi also supported growth of the yeast in a deferrated medium. These results suggest that C. albicans has an iron-uptake mechanism which enables it to obtain iron by utilizing candidal and non-candidal siderophores.

Candida albicans↗

Effect of elevated temperatures and low levels of trace metals on the growth and phenotypic development of Candida albicans.

A combination of elevated temperatures (within the human febrile range) and trace metal chelation were investigated for their effects on the inhibition of growth and phenotypic development of the dimorphic yeast Candida albicans (strain 3153A). The ability of specific cations to relieve the phenotypic inhibition that occurred also was tested. Elevated temperatures alone (to 41 degrees C) only delayed the timing of the phenotypic development. When compared to the results obtained at 37 degrees C, the recombination of elevated temperature and addition of the trace metal chelator, 1,10-phenanthroline, did not further suppress phenotypic development, but the combination did decrease the viability of C. albicans. When 24 to 48 h stationary phase singlet cells were released into a medium containing 100 microM 1,10-phenanthroline (pH 6.5), supplemental iron (200 microM) alleviated the suppression of mycelium formation at 41 degrees C, whereas under conditions favoring bud formation (pH 4.5), both iron and zinc circumvented suppression and promoted budding. Through studies on the interaction of temperature stress and trace metal availability our data revealed the requirement for iron mycelium formation whereas both iron and zinc may be needed for bud formation.

Candida albicans↗