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Biomedical subjects

M Khan

Publications and source records attributed to M Khan.

At least 37 records · Page 2Linked to original sources
PubMed2005

A comparative study on effect of lamivudine in wild and precore mutant variety of chronic hepatitis B virus infected patients.

The aim of this study is to evaluate the effectiveness of lamivudine treatment in both precore mutant and wild type of chronic hepatitis B (CHB) patients. The study was done on sixty CHB patients of both sexes seeking treatment in the Outpatient Department and admitted patients of Mymensingh Medical College Hospital. The patients were divided into two groups. Group A included chronic hepatitis B patients with raised ALT (> 80 u/l ) with HBeAg positivity, and group B included precore mutant variety of CHB patients with raised ALT (> 80 u/l) with HBeAg negativity. In Group-A, after 1 year of completion of lamivudine therapy there was 86.67% normalization of ALT, 23.33% HBeAg loss, 16.67% anti-HBeAg development and 73.33% HBV DNA loss. In Group-B, there was 76.67% normalization of ALT and 73.33% HBV DNA loss after 1 year of completion of therapy. In the present study, it was observed that lamivudine is equally effective in both wild and precore mutant variety of CHB patients. This was reflected by normalization of ALT and loss of HBV DNA. This study also shows the reappearance of HBV DNA during the later half of Lamivudine therapy which is due to YMDD mutation.

Antiviral Agents↗
PubMed2005

All that glitters is not gold ... all that faints is not slow.

An 82 year old man presented with multiple syncopal episodes. Since his ECG showed LBBB (left bundle branch block) with first degree AV block, he was advised permanent pacemaker implantation. However, a wide QRS tachycardia on the Holter raised the possibility of tachycardia-mediated syncope. EP (electrophysiological) studies revealed easily and repeatedly inducible short lasting slow-fast AVNRT (atrioventricular nodal reentry tachycardia) with severe hypotension. After RF ablation of the slow pathway, he is asymptomatic at six month follow-up.

Aged↗
PubMed2004

Carbon sequestration and estimated carbon credit values as measured using 13C labelling and analysis by means of an optical breath test analyser.

Recent developments in optical systems (isotope-selective non-dispersive infrared spectrometry) for breath testing have provided a robust, low-cost option for undertaking (13)C analysis. Although these systems were initially developed for breath testing for Helicobacter pylori, they have an enormous potential as a soil science research tool. The relatively low cost of the equipment, US$15,000-25,000, is within the research budgets of most institutes or universities. The simplicity of the mechanisms and optical nature mean that the equipment requires relatively low maintenance and minimal training. Thus methods were developed to prepare soil and plant materials for analysis using the breath test analyser. Results that compare conventional mass spectrometric methods with the breath test analyser will be presented. In combination with simple (13)C-plant-labeling techniques it is possible to devise methods for estimating carbon sequestration under different agronomic management practices within a short time frame. This enables assessment of the carbon credit value of a particular agronomic practice, which can in turn be used by policy makers for decision-making purposes. For global understanding of the effect of agricultural practices on the carbon cycle, data are required from a range of cropping systems and agro-ecological zones. The method and the approach described will enable collection of hard data within a reasonable time.

Animals↗
PubMed2004

Hypnosis for schizophrenia.

BACKGROUND: Many people with schizophrenia continue to experience symptoms despite the use of conventional treatments. Alternative therapies such as hypnosis, in conjunction with conventional treatments, may prove beneficial to them. OBJECTIVES: To investigate the use of hypnosis for people with schizophrenia or schizophrenia-like illnesses compared to standard care and other interventions. SEARCH STRATEGY: We searched the Cochrane Schizophrenia Group's Register (January 2003), contacted the Cochrane Complementary Medicine Field for additional searching, hand searched references of included or excluded studies and made personal contact with authors of relevant trials. SELECTION CRITERIA: All randomised or double blind controlled trials that compared hypnosis with other treatments or standard care for people with schizophrenia. DATA COLLECTION AND ANALYSIS: Studies were reliably selected, quality assessed and data extracted. Data were excluded where more than 50% of participants in any group were lost to follow up. For binary outcomes we calculated a fixed effects risk ratio (RR) and its 95% confidence interval (CI). MAIN RESULTS: We included three studies (total n=149). When hypnosis was compared with standard treatment no one left between 1-8 weeks (n=70, 2 RCTs, Risk Difference 0.00 CI -0.09 to 0.09). Mental state scores were unaffected (n=60, 1 RCT, MD BPRS by 1 week -3.6 CI -12.05 to 4.8) as were measures of movement disorders and neurocognitive function. Compared with relaxation, hypnosis was also acceptable (n=106, 3 RCTs, RR leaving the study early 2.00 CI 0.2 to 2.15) and had no discernable effect on mental state (n=60, 1 RCT, MD BPRS by 1 week -3.4 CI -11.4 to 4.6), movement disorders or neurocognitive function. Hypnosis was as acceptable as music (Sibelius) by 4 weeks (n=36, RR leaving the study early 5.0, CI 0.3 to 97.4). REVIEWERS' CONCLUSIONS: The studies in this field are few, small, poorly reported and outdated. Hypnosis could be helpful for people with schizophrenia but to ascertain this requires better designed, conducted and reported randomised studies.

Humans↗
PubMed2004

Perinatal tuberculosis and HIV-1: considerations for resource-limited settings.

Tuberculosis is the commonest HIV-1-related disease and the most frequent cause of mortality in young women in endemic regions. Tuberculosis and HIV-1 are independent risk factors for maternal mortality and adverse perinatal outcomes, and in combination have a greater impact on these parameters than their individual effects. In referral health centres in southern Africa around one-sixth of all maternal deaths are due to tuberculosis/HIV-1 coinfection. One-third (37%) of HIV-1-infected mothers with tuberculosis are severely immunocompromised, with CD4 counts of fewer than 200 cells/microL compared with 14-19% in mothers recruited into major mother-to-child intervention trials in Europe. Babies born to mothers with tuberculosis/HIV-1 also have higher rates of prematurity, low birthweight, and intrauterine growth restriction. Transmission rates of HIV-1 from mother to infant are around 25-45% in resource-limited settings, while that for mother-to-child-transmission of tuberculosis is 15% within 3 weeks of birth. We highlight this emergent problem, and discuss the dilemmas associated with diagnosis and management of pregnant HIV-1-infected mothers with tuberculosis, and their newborn babies.

Africa, Southern↗
PubMed2004

Dehydroepiandrosterone sulphate (DHEAS) inhibits growth of human vascular endothelial cells.

Dehydroepiandrosterone sulphate (DHEAS) is a steroid product of the adrenal gland, which circulates in high concentrations, but whose functions are largely unknown. There is evidence for antiproliferative effects of DHEAS in neoplastic tissue. The present study was designed to investigate the effects of DHEAS on vascular endothelial cell proliferation. It was found that DHEAS at physiological concentrations (10 microM) caused inhibition of cellular growth, which was reversible following removal of the steroid. This effect was not mimicked by other steroids, suggesting that it is not mediated by androgen or estrogen receptors. Uptake of 3H-thymidine was not altered by DHEAS, suggesting that this steroid may induce apoptosis in vascular endothelial cells.

Cell Proliferation↗
PubMed2004

Effects of pioglitazone on the components of diabetic dyslipidaemia: results of double-blind, multicentre, randomised studies.

A total of 3,713 patients with poorly controlled type 2 diabetes were enroled into four multicentre, double-blind studies and randomised to receive pioglitazone, sulphonylurea, metformin or a combination of two of these agents for up to 52 weeks. Data from patients with a lipid evaluation, at week 52, were pooled, and treatment groups were compared using analysis of covariance. Pioglitazone, alone or combined with metformin or sulphonylurea, resulted in mean decreases in triglycerides (-9 to -11%), total/HDL cholesterol ratio (-9 to -10%) and free fatty acid (-0.051 to -0.123 mmol/l) and mean increases in HDL cholesterol (17 to 20%). The sustained, favourable effects of pioglitazone on important components of diabetic dyslipidaemia may contribute to reduced cardiovascular disease risk, among patients with type 2 diabetes.

Adult↗
PubMed2004

Vertical transmission of Mycobacterium tuberculosis in KwaZulu Natal: impact of HIV-1 co-infection.

BACKGROUND: Increases in perinatal TB have paralleled the exacerbation of the TB epidemic in KwaZulu Natal. The exact risks for vertical transfer of Mycobacterium tuberculosis (VTRTB) to the baby are unknown, as is the impact of HIV-1 co-infection, which frequently accompanies maternal TB disease in the region. DESIGN: Prospective case series study of 82 HIV-1-infected and 25 non-infected pregnant mothers, King Edward VIII Hospital, KwaZulu Natal, South Africa. RESULTS: Perinatal mortality in HIV-1/TB diseased mothers was 85/1000 and associated with maternal anaemia (P = 0.02); 46% of newborns were premature, 66% low birth weight and 49% intrauterine growth restricted. These were significantly higher than overall hospital rates (P < 0.01, OR 4.8, 95%CI 3.2-7.0). Sites of detection of maternal TB, distribution of bacteriologically-proven TB, obstetric comorbidity and perinatal morbidity were similar in HIV-1-infected and non-infected mothers. VTRTB was detected in 16 newborns (16%), occurring similarly in bacteriologically-proven and suspected maternal TB disease, with no difference between HIV-1-infected and non-infected mothers. Eleven newborns with VTRTB were HIV-1 exposed; 64% acquired HIV-1 and died from rapidly progressive disease by 10 months of age. HIV-1-infected mothers and their exposed newborns had significantly lower CD4 counts. No association between perinatal maternal viral load, CD4 count or VTRTB was detected. CONCLUSION: Mothers with TB disease in pregnancy are at risk for significant perinatal morbidity, mortality and VTRTB.

AIDS-Related Opportunistic Infections↗
PubMed2003

[Common errors of intraoperative navigation in lateral skull base surgery].

BACKGROUND AND OBJECTIVE: The knowledge of disturbing factors for navigated surgical procedures in lateral skull base surgery will help the user to identify, avoid, and correct these errors. PATIENTS/METHODS: Based on our experiences with 85 patients undergoing surgery of the lateral skull base, errors of hard- and software, of image acquisition and image transfer, of patient registration, user-related errors as well as strategic errors were analyzed. RESULTS: Any impairment of the camera field leads to functional limitation of optical systems to the same extent as electromagnetic systems can be affected by ferromagnetic materials. Standard patient registration procedures as well as the lack of compensation for soft tissue shift may cause problems. CONCLUSIONS: While dealing with navigation devices in lateral skull base surgery, the user must pay critical attention to certain details in order to recognize and interpret possible malfunction.

Computer Systems↗
PubMed2003

[The application of an optical navigation system in endonasal sinus surgery].

BACKGROUND: There are several CAS-systems in use in modern endonasal sinus surgery. The VectorVision Compact is the first optoelectrical system especially designed for such surgery. This paper investigates its reliability and practicability. PATIENTS AND METHODS: The system was used for intraoperative navigation in 60 patients suffering from chronic rhinosinusitis. The accuracy was measured by visual estimation and compared with other navigated systems. RESULTS: The accuracy was 1.9 mm which is comparable to other systems on the market. Navigation was successful and reliable in 83.3% of the patients. Problems occurred mainly due to loss of sight of the referencing balls and when using other surgical instruments. CONCLUSION: The VectorVision Compact was adequate for endonasal sinus surgery. Further improvements incorporating various surgical instruments should broaden its clinical usefulness.

Endoscopes↗
PubMed2003

Is digital image compression acceptable within diabetic retinopathy screening?

AIMS: The National Screening Committee (NSC), whilst recommending the use of digital mydriatic retinal photography for diabetic retinopathy screening, has not yet accepted the use of digitally compressed images for grading. By greatly reducing the file size, however, compression of images is invaluable for storage and for its rapid transmission across computer networks. We undertook a study to compare the different levels of JPEG compression with the original bit-mapped image to determine whether there was any loss of clinical detail following compression. METHODS: Three hundred and thirty images were analysed in this study. These images had been captured from 66 eyes consecutively photographed in a diabetic retinopathy screening programme, using a Sony DXC-950 P 3CCD colour video camera mounted on a Canon CR6-45NMf fundus camera. Single 45 degrees macula-centred images were taken from each eye. The images were compressed using the JPEG algorithm within Adobe Photoshop (version 4.0) and then displayed with a Sony Trinitron colour monitor. Four different levels of compression were used, JPEG-1, JPEG-2, JPEG-3, JPEG-4, and an objective analysis was undertaken using 'lesion counts'. The compressed images were assessed separately and blindly and the results compared with their original BMP images. RESULTS: Eight BMP images could not be evaluated (five right eye and three left eye). A total of 290 images were therefore used in the final evaluation. All the JPEG-1 images with file sizes between 16 and 24 kb were found to be 'pixelated', while the JPEG-4 images (66-107 kb) appeared similar to the original BMP (1.3 Mb) images. Both JPEG-2 and JPEG-3 images had significantly lower counted lesions than the BMP images. CONCLUSIONS: From our findings we can conclude that only some degree of image compression (compression ratios of 1 : 20 to 1 : 12) with file sizes of 66-107 kb is permissible using JPEG format, whereas the images obtained after higher compression ratios may not be suitable for diabetic retinopathy screening.

Adult↗
PubMed2003

Safety of subcutaneous specific immunotherapy with pollen allergen extracts for respiratory allergy.

BACKGROUND: Specific immunotherapy (SIT) is a well-documented treatment for respiratory allergy. However, the major risk of SIT is the development of systemic anaphylactic reactions. OBJECTIVES: To evaluate the safety of SIT given by subcutaneous route for 3 years to patients with seasonal allergic rhinitis (AR) with or without asthma. METHODS: A prospective open-label study of immunotherapy (Chenopodium album, Bermuda grass, or both) in 181 consecutive patients with AR with or without asthma. After an initial dose-escalation phase, a maintenance dose of 0.5 ml of 100,000 PNU/ml was administered monthly for 3 years. The occurrence and severity of systemic reaction (SR) and local reaction was recorded and graded according to the WHO position paper. RESULTS: Of 181 patients enrolled, 57 (31%) did not complete the study (53 due to poor compliance and 4 due to systemic side effects). All 4 patients who developed SR had asthma and all the SR occurred during the dose- escalation phase. Three patients had moderate SR (grade 2), while 1 patient had severe reaction (grade 3). Three of the SR occurred within the first 20 min after injection and 1 SR occurred 2 h after injection. None of the reactions were life threatening and were managed easily. Total rhinitis symptom score decreased from 11.8 at baseline to 7.46 at the end of treatment (p<0.001). The size of the skin prick test reaction to the main sensitising allergen was reduced from 7.48 +/- 2.26 mm at baseline to 5.60 +/- 2.18 mm at the end of treatment, p<001. CONCLUSION: If a strict protocol is used, SIT is safe in AR patients with or without mild asthma and may result in significant subjective and objective improvement.

Adolescent↗
PubMed2003

Distribution of T4 TSH values in children--the Shifa experience.

OBJECTIVE: To evaluate the distribution of Thyroxin (T4) and Thyroid Stimulating Hormone (TSH) values in children of various age groups attending our hospital. METHOD: We have retrospectively reviewed the T4, TSH levels recorded at our hospital in children from birth to 5 years and evaluated the reference intervals for T4 TSH amongst different ages. Non parametric methods were used to establish a 97.5th, 95th, 50th, 5th and 2.5th centiles. RESULTS: In T4 (n=1148) and TSH (n=1142) samples reviewed a TSH surge following delivery showed a sharp decline in the first 4 days of life. This was followed by a more gradual downward trend. Data on T4 estimations showed a similar but more gradual downward trend in advancing age groups. The 5th-95th centile reference range for TSH showed values between 1.7-22.5 (0-4 days; n=992), 0.6-13.3 (5-7 days; n=38), 0.9-14.0 (1 week-1 month; n=38), 0.5-13.6 (1 month-1 year, n=38) and 0.4-12.8 (1-5 years; n=38) microlU/mL. The 5th-95th centile reference range for T4 showed values between 10.7-25.0 (0-4 days; n=995), 6.5-20.4 (5-7 days; n=35), 8.0-18.1 (1 week-1 month; n=38), 6.0-16.1 (1 month-1 year; n=41), 6.9-15.3 (1-5 years; n=39) micro gm/dl. CONCLUSION: We recommend using separate T4 and TSH reference values for children in different age groups. Further large-scale studies should be done in Pakistan to establish these reference values within age groups. A national center for neonatal thyroid screening is highly recommended.

Age Distribution↗