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Biomedical subjects

M Habib

Publications and source records attributed to M Habib.

At least 19 recordsLinked to original sources

First results of detection of PRRSV and CSFV RNA by SYBR Green I-based quantitative PCR.

Porcine reproductive and respiratory syndrome (PRRS) and classical swine fever (CSF) cause significant economic losses to the swine industry worldwide. As both diseases cause similar symptoms, rapid and reliable detection of these diseases is essential for disease surveillance. A quantitative SYBR Green I-based reverse transcription-polymerase chain reaction (RT-PCR) is described for simultaneous and differential diagnosis. The established RT-PCR for the quantitation of PRRSV and CSFV cDNA was found to provide a broad dynamic range, detecting from 10(3) to 10(11) and 10(2) to 10(11) copies of cDNA per reaction, respectively. Sensitivity and specificity of this method were compared with those of conventional RT-PCR and both were equal or superior to the reference method. Reproducibility was tested and the assay was proved very reliable. The assay is timesaving, easy to handle, and highly sensitive and specific. Therefore, it is a powerful tool for detecting PRRSV and CSFV simultaneously for routine outbreak investigation.

Animals↗

Inactivation of infectious bursal disease virus by binary ethylenimine and formalin.

In this experiment conducted to study the inactivation dynamics of infectious bursal disease virus (IBDV) by binary ethylenimine (BEI) in comparison with formalin, IBDV was isolated from the bursa of infected chickens and its confirmation was done by agar gel precipitation test. Viral suspensions were subjected to inactivation with BEI and formalin for pre-set time intervals. BEI was employed at concentrations of 0.001 and 0.002 mol/L while formalin was used at 0.1% and 0.2%. Sampling was done at 6, 12, 24, 36 and 48 h of incubation and samples were tested for their inactivation status in 9-day-old embryonated eggs and 3-week-old broiler chickens. IBDV was completely inactivated by 0.001 and 0.002 mol/L BEI after 36 h of incubation at 37 degrees C, whereas formalin at 0.1% and 0.2% concentrations inactivated IBDV in 24 h.

Animals↗

Central scotoma associated with intraocular silicone oil tamponade develops before oil removal.

BACKGROUND: Unexplained sudden visual loss after removal of silicone oil from the eye has recently been described. We report the occurrence and features of unexplained central scotoma developing with silicone oil in situ in the vitreous cavity. METHODS: A retrospective case series of five patients (from two centres) who reported a central scotoma commencing during silicone oil tamponade was studied. All patients had vitrectomy for macula-on retinal detachment, with ultra-purified silicone oil tamponade (four out of five had giant retinal tear). Investigations included visual acuity, intraocular pressure, optical coherence tomography, fluorescein angiography, visual fields and electrophysiology. RESULTS: All patients reported a central scotoma that appeared during oil tamponade. Visual acuity fell by a mean of 0.93 LogMAR units after onset of the scotoma. After cataract extraction and oil removal, vision remained reduced by a mean of 0.8 units. The mean duration of oil in the eye was 2.7 months when the scotoma was noted by the patient. Investigations were performed after removal of oil. Fluorescein angiography (FFA) was performed in two cases and optical coherence tomography (OCT) in five patients. No abnormality was demonstrated. Electrophysiology was performed in five patients with pattern electroretinography suggestive of macular dysfunction in four patients. CONCLUSION: This is the first case series describing central scotoma associated with silicone oil in situ. Electrophysiology indicated macular dysfunction in most cases. We suggest that early removal of oil in cases with good visual potential should be considered to avoid this sight-threatening complication.

Adult↗

Auditory evoked potential patterns to voiced and voiceless speech sounds in adult developmental dyslexics with persistent deficits.

Auditory evoked potentials (AEPs) were recorded from eight developmental dyslexic adults with persistent reading, spelling and phonological deficits, and 10 non-dyslexic controls to voiced (/ba/) and voiceless (/pa/) consonant-vowel syllables. Consistent with previous data, non-dyslexics coded these stimuli differentially according to the temporal cues that form the basis of the voiced/voiceless contrast: AEPs had time-locked components with latencies that were determined by the temporal structure of the stimuli. Dyslexics were characterized by one of two electrophysiological patterns: AEP pattern I dyslexics demonstrated a differential coding of stimuli on the basis of some temporal cues, but with an atypically large number of components and a considerable delay in AEP termination time; AEP pattern II dyslexics demonstrated no clear differential coding of stimuli on the basis of temporal cues. These data reveal the presence of anomalies in cortical auditory processing which could underlie persistent perceptual and linguistic impairments in some developmental dyslexics. Furthermore, scalp AEP distribution maps showing the difference observed between /ba/ and /pa/ activity over time suggest that the regions implicated in the processing of crucial time-related acoustic cues were not systematically lateralized to the left hemisphere like they were for non-dyslexics. These findings may be conducive to a better understanding and treatment of perceptual dysfunctions in developmental language disorders.

Acoustic Stimulation↗

Comparative study of Anaplasma parasites in tick carrying buffaloes and cattle.

A comparative study on the prevalence of Anaplasma parasite was conducted on ticks carrying buffaloes and cattle. Five hundred blood samples of both animals (250 of each) were collected during February, March and April. Thin blood smears on glass slides were made, fixed in 100% methyl alcohol and examined. Microscopic examination revealed that 205 (41%) animals had Anaplasma parasites, out of which 89, 44 and 72 animals had Anaplasma marginale, Anaplasma centrale and mixed infection respectively. Infected buffaloes and cattle were 75 and 130 respectively. The infection in female was 53 and 92 in buffaloes and cattle respectively. Twenty-two and 92 blood samples of male were found positive in buffaloes and cattle respectively. Comparative study revealed that the cattle were 26.82% more susceptible than buffaloes. The parasite prevailing percentage in female of both animals was slightly higher than that of the male. This investigation was aimed at studying the comparative prevalence of Anaplasma parasite in tick carrying buffaloes and cattle.

Anaplasma↗

The relation of volume with outcome in phacoemulsification surgery.

BACKGROUND/AIMS: High case volume has been associated with better health outcomes for a variety of procedures and conditions including coronary angioplasty, carotid endarterectomy, colorectal surgery, and various types of cancer surgery. The association of volume and outcome has important implications for patient safety and healthcare delivery planning. The relation between surgical volume and outcome has not, as far as is known, been looked at for phacoemulsification alone. METHODS: All cataract surgery performed from 1996 to 2001 by six consultant surgeons was reviewed. Using theatre logbooks and cross checking with the hospital database, the total number of phacoemulsification procedures performed per surgeon per year was calculated. The total number of operations in which it was judged that significant intraoperative complications occurred was also counted. RESULTS: When the data were pooled for all the surgeons there was evidence that complication rate decreased over time (Spearman's rho = -0.319, p = 0.058). If the data were pooled from all the years and all the surgeons then there was strong evidence of a decrease in complication rate with an increase in the number of cases (Spearman's rho = -0.63, p<0.01). CONCLUSIONS: This study is the first to describe a possible relation between volume of surgery and the outcome (as measured by complication rates) for phacoemulsification. There are however some caveats in that the issue of case mix was not addressed and that the results are from a single unit and may not necessarily be generalisable

Clinical Competence↗

Dyslexia: the articulatory hypothesis revisited.

Articulatory disorders have been associated with developmental phonological dyslexia in the literature. However, very few information is available about the articulatory movements involved in speech production in dyslexic children. This study uses aerodynamic/acoustic data to explore how dyslexic children produce bilabial stops in French (/b, p/) within a sentence where they occurred in two positions and in three vowel environments. Average durations of articulatory closure and release were calculated in 10 phonological dyslexic children and two groups of age-matched and reading age-matched controls. Moreover, deviation from a standard pronunciation of the same material was evaluated separately by blind examiners. Our results reveal differences in the timing of the articulatory movements between dyslexics and normal controls, as well as more deviations from the target consonant for the dyslexics than for the controls. These observations are consistent with recent findings pointing to a general deficit in fine motor control in dyslexia.

Articulation Disorders↗

Dyslexia: cultural diversity and biological unity.

The recognition of dyslexia as a neurodevelopmental disorder has been hampered by the belief that it is not a specific diagnostic entity because it has variable and culture-specific manifestations. In line with this belief, we found that Italian dyslexics, using a shallow orthography which facilitates reading, performed better on reading tasks than did English and French dyslexics. However, all dyslexics were equally impaired relative to their controls on reading and phonological tasks. Positron emission tomography scans during explicit and implicit reading showed the same reduced activity in a region of the left hemisphere in dyslexics from all three countries, with the maximum peak in the middle temporal gyrus and additional peaks in the inferior and superior temporal gyri and middle occipital gyrus. We conclude that there is a universal neurocognitive basis for dyslexia and that differences in reading performance among dyslexics of different countries are due to different orthographies.

Adult↗

A longitudinal study of callosal atrophy and interhemispheric dysfunction in relapsing-remitting multiple sclerosis.

OBJECTIVES: To determine if callosal atrophy and interhemispheric dysfunction can be detected in the early stages of relapsing-remitting multiple sclerosis (MS) and to evaluate their progression in relation to the disability and evolution of lesions seen on magnetic resonance imaging during a 5-year period. METHODS: We compared 30 patients who had clinically definite early-onset replasing-remitting MS and mild disability with control subjects. Regional and segmental callosal size and extent of white matter abnormalities on magnetic resonance imaging, as well as performance on tasks exploring interhemispheric transfer of motor, auditory, and sensory information were assessed. Patients with MS were evaluated at baseline and after 5 years. Physical disability was determined at both times using the Expanded Disability Status Scale score. RESULTS: Patients with MS were seen with significant callosal atrophy and functional impairment of interhemispheric transfer at baseline that worsened during the 5-year study. A significant correlation was found between the magnitude of disability and the severity of morphological and functional callosal involvement at baseline. This association persisted at year 5. Baseline clinical characteristics such as age and prestudy relapse rate were unrelated to callosal size or interhemispheric performance. However, the number of baseline T2-weighted lesions was correlated with callosal involvement and this relation persisted at year 5. CONCLUSION: Patients who had relapsing-remitting MS in the early stages of the disease and mild disability had significant callosal involvement that progressed over time. The relationship between disability, T2-weighted lesions load, and degree of morphological and functional callosal impairment confirm the potential value of using callosal dysfunction as a surrogate marker of disease progression in MS.

Adult↗

Hepatitis C virus infection in a community in the Nile Delta: risk factors for seropositivity.

The purpose of this study was to identify risk factors for hepatitis C virus (HCV) infection in a rural village in the Nile Delta with a high prevalence of antibodies to HCV (anti-HCV). One half of the village households were systematically selected, tested for anti-HCV, and interviewed: 973 of 3,999 (24.3%) subjects were anti-HCV-positive (reflecting prior HCV infection but not necessarily current liver disease), with nearly equal prevalence among males and females. Anti-HCV prevalence increased sharply with age among both males and females, from 9.3% in those 20 years of age and younger to >50% in those older than 35, suggesting a cohort effect with reduced transmission in recent years. Multivariate regression was used to estimate independent effects of risk factors on seropositivity. Among those over 20 years of age, the following risk factors were significantly associated with seropositivity: age (P <.001); male gender (odds ratio [OR] = 2.5, 95% CI = 1.3-4.7); marriage (OR = 4.1, 2.4-6.9); anti-schistosomiasis injection treatment (OR = 2.0, 1.3-2.9); blood transfusion (OR = 1.8, 1.1-2.9), invasive medical procedure (surgery, catheterization, endoscopy, and/or dialysis) (OR = 1.5, 1.1-1.9); receipt of injections from "informal" health care provider (OR = 1.3, 1.0-1.6); and cesarean section or abortion (OR = 1.4, 1.0-1.9). Exposures not significantly related to anti-HCV positivity in adults included: history of, or active infection with, Schistosoma mansoni, sutures or abscess drainage, goza smoking in a group, and shaving by community barbers. Among those 20 years old or younger, no risk factors were clearly associated with anti-HCV positivity; however, circumcision for boys by informal health care providers was marginally associated with anti-HCV (OR = 1.7, 1.0-3.0). Prevention programs focused primarily on culturally influenced risks in rural Egyptian communities are being implemented and evaluated.

Adolescent↗

Increased fecal IgE among infants in a rural community of Egypt: an analysis of associated risk factors.

Newborns in rural Bilbeis, Egypt were followed to 1-year of age to document the incidence and risk factors associated with the development of fecal IgE. Factors associated with increased fecal IgE included infants aged 3-6 months (relative risk (RR) = 3.28, 95 per cent confidence intervals (CI) = 1.03-13.60, p < 0.05) and mother being vaccinated antenatally (RR = 2.17, CI - 1.01-4.61, p < 0.05). Decreased fecal IgE was observed with consumption of rice (RR = 0.37, CI = 0.12-0.94, p < 0.05), biscuits (RR = 0.43, CI = 0.15-0.99, p < 0.05), potatoes (RR = 0.39, CI = 0.11-0.98, p < 0.05), and fruits and vegetables (RR = 0.20, CI = 0.02-0.80, p < 0.05). After multivariate adjustment, increased risk was observed with consumption of milk pudding (RR = 7.48, CI = 1.54-36.20, p < 0.05) and wet-nursed infants (RR = 2.77, CI = 1.17-6.54, p < 0.05). Infants who were completely breastfed (RR = 0.13, CI = 0.02-0.68, p < 0.05) and infants' family owning a television set (RR = 0.29, CI = 0.12-0.67, p < 0.05) were less likely to develop fecal IgE. Our findings indicate that prelacteal feeding with certain foods, early supplementation of breastfeeding, and sociodemographic factors are associated with increased fecal IgE.

Analysis of Variance↗

Impact of breast-feeding on Giardia lamblia infections in Bilbeis, Egypt.

A total of 152 infants were followed from birth to 1 year of age in a rural community of Egypt to document Giardia lamblia infection and to determine the effect of breast-feeding on enteric infections by this protozoan. Asymptomatic Giardia infections persisted as long as 4 months, with a mean duration of excretion of 7.18 weeks. The incidence of asymptomatic infection was 4.5 episodes per child-year. Exclusively breast-fed infants had lower risk for asymptomatic (odds ratio [OR] = 0.66, 95% confidence interval [CI] = 0.45-0.96, P < 0.05) and symptomatic infections (relative risk [RR] = 0.50, 95% CI = 0.27-0.90, P < 0.05). Furthermore, breast-fed infants had fewer clinical manifestations, including mucus in stool (23.8% versus 76.2%, P = 0.08), loss of appetite (17.6% versus 82.3%, P < 0.05), and abdominal tenderness (17% versus 82.9%, P < 0.05) compared with infants who were not exclusively breast-fed. Breast-feeding should be considered as an effective means to prevent Giardia infections and should be encouraged in regions where G. lambia is highly endemic.

Animals↗

[Developmental dyslexia: contribution of modern neuropsychology].

In France about 1 million children are thought to present learning disabilities for reading that in most cases correspond to developmental dyslexias. These are specific and constitutional deficits that prevent rapid and automatic reading abilities from developing, in spite of a normal intelligence and normal visual and auditory acuity. The most frequent form of dyslexia is called "phonological dyslexia" as it results from a deficit of perception and manipulation of phonemes (i.e. "phonological awareness"). Functional neuro-imaging has great potential for helping understand such functional deficits that are likely to be caused by microscopic abnormalities such as micro-polygyria localised in the perisylvian cortex. Tomographic methods have shown deficits of activation of these cortical areas. Electrophysiological methods revealed abnormalities of various events such as MMN or N400, and more recently, delayed latencies of earlier markers suggesting deficits of encoding short-lived features of speech signal.

Awareness↗

Sociodemographic, environmental and clinical risk factors for developing persistent diarrhoea among infants in a rural community of Egypt.

The study documents the incidence of persistent diarrhoea and its sociodemographic, household, environmental and clinical risk factors. One hundred and fifty-two newborns were followed for the first 12 months of life in Bilbeis, Egypt. The household of each participant was surveyed at baseline and was visited twice a week. The study infants experienced persistent diarrhoea at a rate of 0.51 episode/case per year. Development of persistent diarrhoea was associated with water storage in mud-containers (Odds ratio [OR] = 4.36, confidence interval [CI] 1.4-14.8), pump-water supply (OR = 3.5, CI 1.2-10.2), and absence of a latrine in the household (OR = 2.74, CI 1.01-7.38). Detection of faecal IgE (OR = 3.32, CI 1.0-10.9) and high stool frequency (OR = 2.95, CI 1.1-7.8) appeared as important clinical predictors for the onset of persistent diarrhoea. The incidence of persistent diarrhoea among young infants in Bilbeis, Egypt, was high. Sociodemographic, environmental and clinical parameters were important risk factors for the development of persistent diarrhoea.

Chronic Disease↗

Developmental dyslexia: atypical cortical asymmetries and functional significance.

Using brain magnetic resonance imaging, we measured in 16 young developmental dyslexic adults and 14 age-matched controls cortical asymmetries of posterior language-related areas, including Planum temporale and parietal operculum cortical ribbon, and of the inferior frontal region related in the left hemisphere to speech processing. In addition, we assessed the sulcal morphology of the inferior frontal gyrus in both groups according to a qualitative method. The dyslexic subjects also performed specific tasks exploring different aspects of phonological and lexical-semantic processes. Results showed that: (1) contrary to most results reported in the literature, there is a lack of any morphological difference relative to Planum temporale asymmetry between the two groups; (2) there are significant differences between dyslexic and control subjects relative to frontal areas; (3) concerning the parietal region, there is a more asymmetrical pattern towards the left side in dyslexic subjects than in controls; and (4) relations in dyslexic subjects between parietal asymmetry coefficient and the level of performance in a phonological task have a particular reliance on verbal short-term memory, frontal asymmetry and performance in a non-word reading task. Considering these results it is suggested that phonological segmentation skills may relate to frontal lobe morphology, while phonological memory-based impairment in people with dyslexia may rather relate to parietal lobe morphology.

Adult↗

Validation of the Frenchay Activities Index in a general population aged 16 years and older.

OBJECTIVES: To assess the validity and reliability of the Frenchay Activities Index (FAI) and to establish age and sex norms in people at or over the age of 16 years. DESIGN AND SETTING: Postal questionnaire survey to 1280 people randomly selected from 8 Health Authority patient registers in England. MAIN OUTCOME MEASURES: FAI scores, subscale scores by age and sex, health status, perceived level of activity, and subjects' opinions on how well the FAI reflected their activities. Test-retest reliability was measured in 1 Health Authority. RESULTS: The response rate was 49%. Men scored lower than women overall and on the domestic activities subscale. Respondents between the ages of 16 and 24 years and those over 85 years had the lowest FAI scores. FAI scores were related to self-reported health status, self-reported levels of activity, and presence of long-standing illness/disability. The FAI has high test-retest reliability. Qualitative data suggested that items such as sport, physical exercise, and caring for children should be included to make the FAI suitable for a wider age range. CONCLUSION: The FAI has good construct validity, particularly in middle-aged and elderly people, and is reliable. For the FAI to be valid in nonstroke populations, items specific to younger people must be incorporated into it. We have established preliminary age and sex norms that should be interpreted with caution, given the low response rate.

Activities of Daily Living↗

Hepatitis C virus (HCV) infection in a community in the Nile Delta: population description and HCV prevalence.

This report describes a cross-sectional survey of the prevalence of antibodies to hepatitis C virus (anti-HCV) in a rural Egyptian community in the Nile Delta. One half of the village households were systematically selected and examined by questionnaire and testing sera for anti-HCV and HCV RNA. Blood samples were obtained from 3, 888 (75.4%) of 5,156 residents >/=5 years of age; an additional 111 samples were obtained from children younger than 5 years. Overall, 973 (24.3%) of 3,999 residents were anti-HCV-positive, and the age- and gender-adjusted seroprevalence was 23.7%. Anti-HCV prevalence increased sharply with age, from 9.3% in those 20 years of age and younger to >50% in those older than 35 years. Currently or previously married individuals were more likely to be seropositive than those never married, controlling for age (Mantel-Haenszel risk ratio = 1.8; 95% CI: 1.3, 2.6). Of the 905 anti-HCV-positive samples tested, 65% were also positive for HCV RNA. Active schistosomal infection was not associated with anti-HCV status; however, history of antischistosomal injection therapy (reported by 19% of anti-HCV positives) was a risk for anti-HCV (age-adjusted risk ratio = 1.3; 95% CI: 1.2, 1.5). This study, the largest community-based survey to date, supports earlier reports of high levels of anti-HCV among adults in rural areas of Egypt, although many of those who are seropositive will not have active liver disease. The large reservoir of HCV infection in the community provides an opportunity to investigate risk factors for transmission, the natural history of infection and effectiveness of preventive methodologies, and raises concern about the prospect of an increasing incidence of chronic liver disease in the coming decades.

Adult↗