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Biomedical subjects

M Halim

Publications and source records attributed to M Halim.

At least 19 recordsLinked to original sources
PubMed2003

Potential availability of heavy metals to phytoextraction from contaminated soils induced by exogenous humic substances.

Effective phytoremediation of soils contaminated by heavy metals depends on their availability to plant uptake that, in turn, may be influenced by either the existing soil humus or an exogenous humic matter. We amended an organic and a mineral soil with an exogenous humic acid (HA) in order to enhance the soil organic carbon (SOC) content by 1% and 2%. The treated soils were further enriched with heavy metals (Cu, Pb, Cd, Zn, Ni) to a concentration of 0, 10, 20, and 40 microg/g for each metal and allowed to age at room temperature for 1 and 2 months. After each period, they were extracted for readily soluble and exchangeable (2.5% acetic acid), plant-available (DTPA, Diethylentriaminepentaacetic acid), and occluded (1 N HNO(3)) metal species. Addition of HA generally reduced the extractability of the soluble and exchangeable forms of metals. This effect was directly related to the amount of added HA and increased with ageing time. Conversely, the potentially plant-available metals extracted with DTPA were generally larger with increasing additions of exogenous HA solutions. This was attributed to the formation of metal-humic complexes, which ensured a temporary bioavailability of metals and prevented their rapid transformation into insoluble species. Extractions with 1 N HNO(3) further indicated that the added metals were present in complexes with HA. The observed effects appeared to also depend on the amount of native SOC and its structural changes with ageing. The results suggest that soil amendments with exogenous humic matter may accelerate the phytoremediation of heavy metals from contaminated soil, while concomitantly prevent their environmental mobility.

Biodegradation, Environmental↗
PubMed2001

Evaluation of patient characteristics and utilisation of invasive cardiac procedures in a UK ethnic population with unstable angina pectoris.

OBJECTIVES: To evaluate patient characteristics and utilisation of invasive cardiac procedures in a UK ethnic population with unstable angina pectoris (UAP). DESIGN: Retrospective, observational study. SETTING: Tertiary referral cardiology centre in the United Kingdom serving a large Asian ethnic population. SUBJECTS: White and Asian patients undergoing PTCA for UAP over a 2.5-year period at a UK referral cardiology centre from a comprehensive PTCA database. Data were also collated for all emergency admissions with unstable angina, or angina (type unspecified), to our institute. MAIN OUTCOME MEASURES: Demographic and angiographic characteristics of patients undergoing PTCA. Frequency of usage of invasive cardiac procedures was determined in emergency angina admissions. RESULTS: From January 1997 to July 1999, 435 White and 36 Asian patients underwent PTCA for UAP at our institute. Asian patients were on average 4.4 years younger (P=0.015), had 19.3% more diabetes (P=0.003) and 19.7% less smoking (P=0.007). Trends to more single vessel disease in Whites and more double vessel disease in Asians were observed, with similar rates of triple vessel disease. Interestingly, Asians also had trends towards more left-sided coronary artery disease and revascularisation, smaller vessels and less bail-out stenting. Asian patients were significantly less likely to undergo coronary angiography, OR 0.64 (CI 0.45-0.91, P=0.012), during the index admission, and showed a trend to less PTCA. CONCLUSIONS: Asian patients with unstable angina pectoris appear to have clinical and angiographic differences from their White counterparts, and are less likely to have invasive cardiac procedures deployed. The reasons for these observations require elucidation and the prognostic significance of these findings is uncertain.

Aged↗
PubMed2000

The spectrum of Fusarium infection in immunocompromised patients with haematological malignancies and in non-immunocompromised patients: a single institution experience over 10 years.

Fusarium is a newly emerging fungal pathogen associated with significant morbidity and mortality in the immunocompromised host. We have reviewed our hospital's experience with Fusarium between 1985 and 1995. Fusarium species were isolated from 22 specimens, representing 11 patients. Cases were not clustered by time period. The median age of the patients was 36.5 years (range 17-69 years). The sources of the organism were 12 skin lesions from eight patients, seven blood cultures from two patients and one specimen each from a Hickman catheter tip, nail clippings and a bronchoalveolar lavage. Seven of the patients had chemotherapy-induced neutropenia when the Fusarium was isolated. Five of them developed invasive fusarosis during acute leukaemia induction treatment. They remained neutropenic, and none survived. The other two patients recovered from neutropenia and were treated successfully for this infection. The remaining four patients were not neutropenic or immunocompromised. Three grew Fusarium from skin or nail clippings and one from bronchial alveolar lavage (BAL). There was no evidence of invasive disease in any of the four. None of them received antifungal therapy, and they were all alive at last follow-up. We conclude that Fusarium is a newly emerging infection in neutropenic patients. A high index of suspicion, especially for skin lesions, will help in early diagnosis before systemic and visceral dissemination. Excision of the initial focus of infection and antifungal therapy, aided by speedy neutrophil recovery, are likely to protect patients threatened with these fatal infections. Fusarium isolated from non-neutropenic, non-immunosuppressed patients is not significant and does not merit systemic antifungal treatment.

Adolescent↗
PubMed1999

Coronary artery stenting in unstable angina pectoris: a comparison with stable angina pectoris.

OBJECTIVE: To compare early complication rates in unselected cases of coronary artery stenting in patients with stable v unstable angina. SETTING: Tertiary referral centre. PATIENTS: 390 patients with stable angina pectoris (SAP) and 306 with unstable angina (UAP). Patients treated for acute myocardial infarction (primary angioplasty) or cardiogenic shock were excluded. INTERVENTIONS: 268 coronary stents were attempted in 211 patients (30.3%). Stents used included AVE (63%), Freedom (14%), NIR (7%), Palmaz-Schatz (5%), JO (5%), and Multilink (4%). Intravascular ultrasound was not used in any of the cases. All stented patients were treated with ticlopidine and aspirin together with periprocedural unfractionated heparin. RESULTS: 123 stents were successfully deployed in 99 SAP patients v 132 stents in 103 UAP patients. Failed deployment occurred with nine stents in SAP patients, v four in UAP patients (NS). Stent thrombosis occurred in four SAP patients and 11 UAP patients. Multivariate analysis showed no relation between stent thrombosis and clinical presentation (SAP v UAP), age, sex, target vessel, stent length, or make of stent. Stent thrombosis was associated with small vessel size (p < 0.001) and bailout stenting (p = 0.01) compared with elective stenting and stenting for suboptimal PTCA, with strong trends toward smaller stent diameter (p = 0.052) and number of stents deployed (p = 0.06). Most stent thromboses occurred in vessels < 3 mm diameter. CONCLUSIONS: Coronary artery stenting in unstable angina is safe in vessels >/= 3 mm diameter, with comparable initial success and stent thrombosis rates to stenting in stable angina.

Angina Pectoris↗
PubMed1998

Preliminary experience of the DIAS computer model in providing insulin dose advice to patients with insulin dependent diabetes.

The Diabetes Advisory System (DIAS) is a model of human glucose metabolism which predicts hourly blood glucose concentrations and provides advice on insulin dose. Its ability to provide appropriate advice was assessed in 20 well-controlled IDDM patients (mean (SD) age 38 (11), duration 17 (9) years; HbA1 8.8 (0.9)%, reference range 5.4-7.6%). Patients recorded blood glucose measurements, insulin dose and food intake for 4 days. These data were used to generate insulin dose advice by both DIAS and a diabetes specialist nurse. Patients were then allocated to follow either DIAS or nurse advice for a further 4 days. There was no significant difference in mean recorded blood glucose values or frequency of reported hypoglycaemia between the DIAS and nurse groups either before or after insulin dose adjustment. The DIAS model, however, generated significantly lower insulin dose advice than the nurse (median (range)% change in insulin dose: DIAS group -13.3% (-25.0 to +11.6) versus nurse group 0% (-8.7 to +2.5), P < 0.05). We conclude that, in the patients studied, DIAS provided insulin dose advice which maintained good short term control of diabetes, despite significant reductions in dose in some cases.

Adult↗
PubMed1994

Neuroschistosomiasis myelopathy: case report.

A case of intramedullary neuroschistosomal granuloma in a 15-year-old girl is reported. Despite the fact that Saudi Arabia is endemic for schistosomiasis, neuroschistosomiasis has rarely been reported from that country. A review of the literature on the incidence, pathogenesis, clinical patterns and management of neuroschistosomiasis, particularly myelopathy, is given.

Adolescent↗
PubMed1993

Histologically advanced chronic hepatitis C treated with recombinant alpha-interferon: a randomized placebo-controlled double-blind cross-over study.

Chronic hepatitis C is common in Saudi Arabia and most often presents in an advanced stage. To assess the response of patients to interferon, a randomized placebo-controlled double-blind study was undertaken. All but 1 patient had cirrhosis or fibrosis before interferon. After a 24-week observation period patients received alpha 2a interferon, 3 mega units sc tiw or placebo for 24 weeks, then the opposite treatment for another 24 weeks followed by 24 weeks of observation. Liver biopsies were performed before and after each of the treatment phases. Twenty-two out of 24 patients completed the study. The mean alanine aminotransferase (ALT) levels fell from 150.7 +/- 118.7 units/l to 91.0 +/- 42.6 units/l after 6 months interferon treatment (P = 0.03) but only 3 patients (14%) had complete normalization of mean ALT levels and 4 (18%) had > 50% reduction. The mean hepatitis activity index fell from 12.2 +/- 2.6 immediately before to 11.6 +/- 2.5 just after interferon (P = 0.4). After interferon there was an insignificant raise in 6-month mean ALT. Hepatitis C virus-RNA was positive in all 17 patients tested and remained so after treatment. Side-effects were mild and well tolerated. Alpha interferon 3 mega units tiw for 24 weeks is not an effective treatment of histologically advanced chronic hepatitis C.

Adult↗
PubMed1993

Shortening of the poly(A) tail at the 3'-end of mRNA requires its translation.

We report here that when alpha- or beta-globin mRNAs were hybridized with their alpha- or beta-complementary DNAs, respectively, and then translated in rabbit reticulocyte lysates, globin synthesis as well as shortening of the poly(A) tail were much less than that observed with nonhybridized mRNA. Furthermore, when the hybrid (alpha-globin mRNA/alpha-cDNA) was translated in the presence of nonhybrid (alpha-globin mRNA), the estimated average shortening of the poly(A) tails of the hybrid and the nonhybrid were 8% and 40%, respectively. Similar results were obtained when a hybridized beta-globin mRNA with beta-cDNA was incubated in the same translation mixture with beta-globin mRNA. No globin synthesis occurred in the mixtures containing the cDNA-mRNA hybrids only. In the mixtures containing both the hybrid and the nonhybridized mRNAs, globin was synthesized at a rate similar to that observed in a translation reaction mixture alone, that is, in the absence of any hybrid.

Animals↗
PubMed1992

Comparison between single (Inoue) and double balloon mitral valvuloplasty: immediate and short-term results.

This study compared the results in 60 consecutive patients with severe rheumatic mitral stenosis, who underwent percutaneous double-balloon mitral valvuloplasty by means of a combination of 20 mm + 20 mm diameter balloon catheters (group A), with a similar group of 60 consecutive patients who underwent single (Inoue) balloon mitral valvuloplasty (group B). After balloon mitral valvuloplasty the hemodynamic measurements showed significant improvement in both groups: in groups A and B, respectively, mitral valve area calculated with the Gorlin formula increased from 0.9 +/- 0.2 to 2.1 +/- 0.5 cm2 (p less than 0.001) and from 0.8 +/- 0.2 to 1.9 +/- 0.4 cm2 (p less than 0.001). There was a significant improvement in cardiac functional status in both groups. There was no significant difference between the groups with regard to clinical or hemodynamic improvement, technical failure rate, inadequacy of dilatation, or complications. However, the double-balloon technique was more complex and involved a longer screening time--group A, 40 +/- 12 minutes; group B, 21 +/- 10 minutes (p less than 0.001). In our institution the disposable supplies used for the Inoue balloon technique were 40% more expensive than those used for the double-balloon technique.

Adolescent↗
PubMed1992

Spontaneous esophageal perforation in herpes simplex esophagitis.

A 32-yr-old, previously healthy man with severe chest pain of sudden onset was found to have purulent pericarditis and pleural effusions. Several days later, an esophagogram revealed a perforation of the thoracic esophagus. Endoscopy showed a picture highly suggestive of a late stage of an extensive herpes simplex virus (HSV) esophagitis. Biopsies revealed evidence of massive HSV infection, confirmed by immune microscopy and virus culture. At surgery, a mediastinal abscess was found, and an esophageal perforation was identified. These findings suggest that the etiology of the perforation was an unusually severe herpetic infection. To our knowledge, HSV esophagitis has not previously been implicated as the cause of spontaneous esophageal perforation.

Adult↗
PubMed1990

Fuzzy Logic for medical expert systems.

The use of linguistic approximation enables knowledge to be represented in a more meaningful way and this is especially important in medical domain as it involves a lot of subjective decision making; Fuzzy Logic, introduced by Zadeh, has the ability to represent this imprecise expression. In this paper, an alternative approach of Fuzzy Logic in handling the approximate reasoning in expert systems will be described. The approach does not use the General Modus Ponen on the compositional rule of inference, but instead it uses a collection of rules to specify the properties of the inference (in making decision). An example of medical domain is described as its application.

Diagnosis, Computer-Assisted↗
PubMed1988

Mechanism of mitral valve area increase by in vitro single and double balloon mitral valvotomy.

The mechanism of mitral valve area increase by double balloon mitral valvotomy in vitro has not been defined, nor have the mitral valve area results achieved by single versus double balloon mitral valvotomy technique been compared. After a selection of 29 intact mitral valves excised at cardiac surgery from patients with a mitral valve area less than or equal to 1.5 cm2 was made, double balloon mitral valvotomy was attempted in 14 valves using two 20-mm diameter balloon catheters (group 1) and single balloon mitral valvotomy using a 20-mm balloon was undertaken in 15 valves (group 2). In group 1 the mitral valve area increased from 0.9 +/- 0.03 to 1.9 +/- 0.05 cm2 (mean +/- standard error of the mean) (p less than 0.001), with a mean anterior commissural split of 5.3 +/- 0.2 mm and a posterior split of 4.1 +/- 0.2 mm. Following single balloon valvotomy (group 2), the mean mitral valve area increased from 0.8 +/- 0.03 to 1.2 +/- 0.03 cm2 (p less than 0.001), with the mean anterior commissural split being 2.6 +/- 0.2 mm and the posterior 2.1 +/- 0.2 mm. Ten mitral valves from group 2 underwent a second dilatation using the double balloon technique and the mitral valve area increased further from 1.2 +/- 0.06 to 1.9 +/- 0.06 cm2 (p less than 0.001). Overall, commissural splitting occurred preferentially in calcified commissures (81%), as opposed to only 56% of noncalcified commissures. Commissural splitting is the manner in which mitral valve area increases after double balloon mitral valvotomy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗