Sufian M. El-Assouli

Bacteria and viruses that cause respiratory tract infections during the pilgrimage (Haj) season in Makkah, Saudi Arabia

objective To determine the incidence and type of RTI‐causing bacteria and viruses during a period of epidemic infections.

Genetic and Antigenic Analysis of Human Rotavirus Prevalent in Al-Taif, Saudi Arabia

The subgroup, serotype and electropherotype diversity of human rotavirus strains was investigated in Al-Taif, Saudi Arabia. Out of 349 faecal samples collected from diarrhoeic children, 150 (43 percent) tested rotavirus positive by a group-A specific enzyme-linked immunosorbent assay (ELISA). The majority (87 percent) of the infected children were below 2 years of age. Subgrouping and serotyping of rotaviruses with specific monoclonal antibodies showed that of the 150 rotavirus positive specimens, 17 percent belonged to subgroup I, 59 per cent belonged to subgroup II, and 24 percent were neither subgroup I nor subgroup II. The specimens were typed, as serotype 1 (43 percent), serotype 2 (5 percent), serotype 3 (11 percent), serotype 4 (10 percent) or mixed serotypes (3 percent). The remaining 41 (27 percent) specimens were untypeable. None of the serotypes showed association with a particular age group. An electrophoretic analysis of viral RNA revealed 11 distinct patterns (six long and five short). The majority, 78 percent were long patterns and 22 percent were short patterns. Analysis of the specimens for which subgroups, serotypes and electropherotypes were available indicated that a given RNA pattern does not correspond to a particular subgroup or serotype.

Genotoxicity of waterpipe smoke in buccal cells and peripheral blood leukocytes as determined by comet assay

Abstract Context: Waterpipe smoke causes DNA damage in peripheral blood leukocytes and in buccal cells of smokers. Objective: To determine the exposure effect of waterpipe smoke on buccal cells and peripheral blood leukocytes in regard to DNA damage using comet assay. Materials and methods: The waterpipe smoke condensates were analyzed by gas chromatography-mass spectrometry (GC-MS). The study was performed on 20 waterpipe smokers. To perform comet assay on bucaal cells of smokers, 10 µl of cell suspension was mixed with 85 µl of pre-warmed 1% low melting agarose, applied to comet slide and electrophoresed. To analyze the effect of smoke condensate in vitro, 1 ml of peripheral blood was mixed with 10 µl of smoke condensate and subjected for comet assay. Results: The GC-MS analysis revealed the presence of 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4on, nicotine, hydroxymethyl furancarboxaldehyde and 3-ethoxy-4-hydroxybenzaldehyde in the smoke condensates. Waterpipe smoking caused DNA damage in vivo in buccal cells of smokers. The tail moment and tail length in buccal cells of smokers were 186 ± 26 and 456 ± 71, respectively, which are higher than control. The jurak and moassel smoke condensates were found to cause DNA damage in peripheral blood leukocytes. The moassel smoke condensate was more damaging. Discussion: There is wide misconception that waterpipe smoking is not as harmful as cigarette smoking. This study demonstrated that waterpipe smoke induced DNA damage in exposed cells. Conclusion: Waterpipe smokes cause DNA damage in buccal cells. The smoke condensate of both jurak and moassel caused comet formation suggesting DNA damage in peripheral blood leukocytes.

Cell cycle kinetics analysis of Hela cells exposed to aphidicolin: Computer simulation

A computer simulation model was developed and used to analyze the inhibitory effect of aphidicolin on the proliferation of Hela cells. Simulation results were compared with actual experimental results [Pedrali-Noy et al. (1980) Nuc. Acid Res. 8, 377] and were found to be in good agreement. Also, the simulation showed that aphidicolin caused cells to be accumulated at the G1/S boundary and that recruitment and synchrony occurred.

Regression models for estimating survival of patients with non-Hodgkin's Lymphoma

Abstract The life-table method is used for estimating the survivorship of 989 patients treated for non-Hodgkins Lymphoma at King Faisal Specialist Hospital and Research Center in Riyadh, Saudi Arabia. Estimates of various survival measures and their standard errors are obtained. Then, four common probability distributions namely; the exponential, Weibull, Gompertz, and the linear hazard are used to estimate the survivorship function, hazard function and the probability density function. Comparison between the log-likelihood values for the estimated data is also made to choose the best fitting model.

Antigenotoxic ketosteroid from the red algae Jania adhaerens

A new ketosteroid, 6β,16β-dihydroxycholest-4-en-3-one (1), in addition to the known 6β-hydroxycholest-4-en-3-one (2), 6β-hydroxycholest-4,22-dien-3-one (3) and 16β-hydroxy-5α-cholestan-3,6-dione (4), was isolated from the red alga Jania adhaerens. The structures were assigned on the basis of 1H- and 13C-NMR experiments. The new compound (1) was evaluated for its genotoxic and cytotoxic activities and found to possess protective antigenotoxicity in human peripheral blood cells.

Cell growth simulation (CGS): the design philosophy

Cell Growth Simulation (CGS) is a software package that simulates the growth of cell cultures, and the effects of different types of agents on the cell populations in vitro. It is a stochastic simulation system based on the cell cycle kinetics. Experiments involving DNA synthesis blocking, mitosis inhibition, labelling and cell kill can be simulated by imitating agents such as thymidine, aphidicoline, hydroxyurea, vincristine, vinblistine, colcemid and others. The model to be simulated is described by the user according to his theoretical convictions, The system provides numerous facilities to help the user describe an experiment and examine the simulation results. A menu driven interactive scheme is used to communicate with the user. CGS has a modular structure and its general structure, design philosophy and capabilities are presented. The system has been developed through the cooperation of industrial engineering, cell biology, medical oncology and computer programming disciplines. It is implemented on...

Epidemiology of Diarrhea in Two Major Cities in Saudi Arabia

The epidemiological pattern of diarrhoeal diseases, causative agents and risk factors of their occurrence in two referral hospitals of Saudi Arabia is presented in this study. Stool specimens from 1726 admitted diarrhoeal cases were examined for parasites, yeast, enteropathogenic bacteria and rotavirus using the ELISA test. 41.3% of cases were due to rotavirus (RVGE) while 53.1% of cases showed no causative pathogens. Mean age of all cases was 20.2 months and RVGE cases showed a steady rise from the neonatal period onward, reaching a peak between 6-14 months. Males accounted for higher percentage of all diarrhoeal cases. Mothers of diarrhoea cases were mostly housewives with low educational level. Bottle fed children showed higher proportion (53.1%) of diarrhoea than other types of feeding suggesting the faeco-oral route of infection and the effect of poor sanitation. A pattern of higher RVGE cases was seen in warmer months in Al-taif and in cooler months in Jeddah. Findings demonstrated the interaction between host, pathogen and environmental factors in the epidemiology of infectious diarrhoeas in developing countries and the areas of possible prevention.

Bacteria and viruses that cause respiratory tract infections during the pilgrimage (Haj) season in Makkah, Saudi Arabia: Respiratory tract infections during the pilgrimage season in Saudi Arabia

OBJECTIVE To determine the incidence and type of RTI-causing bacteria and viruses during a period of epidemic infections. METHOD A total of 395 sputum specimens and 761 throat swabs were collected during the 1991 and 1992 pilgrimage seasons (Haj to Makkah Al-Mukarama, Saudi Arabia) from patients referred to one hospital and three dispensaries with symptoms of respiratory tract infections. All 761 throat swabs of both Haj seasons were also screened for the presence of viral pathogens with monoclonal antibodies specific for 7 viruses known to cause respiratory infections. RESULTS Bacterial pathogens were detected in 118 (29.9%) specimens. During the 1991 Haj season Haemophilus influenzae was the most frequent bacterial pathogen detected (10%), followed by Klebsiella pneumoniae (5.2%), Streptococcus pneumoniae (4.8%), Staphylococcus aureus (3.8%) and Streptococcus pyogenes (2.4%). In the 1992 Haj season Klebsiella pneumoniae was predominant (15.1%), followed by Haemophilus influenzae and Streptococcus pneumoniae (12.3%). Screening of all sputum specimens for acid-fast bacteria showed that the overall incidence rate of tuberculosis was 1%. Cultures from the 761 throat swabs were largely negative for bacteria except for Streptococcus pyogenes isolated from 7 patients. Viruses were detected in 148 (19.5%) specimens with influenza A and adenovirus being the most common viruses. CONCLUSION The pattern of virus prevalence in the 1991 and 1992 pilgrimage seasons was identical: influenza A and adenovirus predominated. Thus these two viruses should be targeted in future prophylactic measures.

Effect of colcemid on CHO cells progression: computer simulation

A computer model has been constructed to simulate the effects of the mitotic inhibitor colcemid on the Chinese hamster ovary (CHO) cells progression through the cell cycle. The simulation was implemented on personal computer. Colcemid treatment severely inhibits the progression of cells in mitosis and causes enrichment of cells into the M phase of the cell cycle. This blockage in M phase was reversible at the drug concentration used, and cells resumed cycle traverse following colcemid removal without any delay. The drug has no effect on the progression of cells from mitosis to G1 G1 to S, S to G2 and from G2 to mitosis.