PubMed Health⌕ Search

Biomedical subjects

S Ibrahim

Publications and source records attributed to S Ibrahim.

At least 37 records · Page 2Linked to original sources
PubMed2001

Plasma angiotensin II, renin activity and serum angiotensin-converting enzyme activity in non-insulin dependent diabetes mellitus patients with diabetic nephropathy.

The renin-angiotensin system (RAS) has been unequivocally implicated as a mediator of diabetic complications. The present study was designed to evaluate the RAS in non-insulin dependent diabetic patients with diabetic nephropathy. Plasma renin activity, plasma angiotensin II and serum angiotensin-converting enzyme (ACE) activity were measured in 45 non-insulin dependent diabetes mellitus (NIDDM) patients and 15 healthy non-diabetic controls. Diabetics were subdivided into 15 normoalbuminuric NIDDM subjects, 15 NIDDM patients with microalbuminuria and 15 diabetics with macroalbuminuria. Mean plasma renin activity for macroalbuminuric diabetics (0.65+/-0.10 ng/ml/hr) was significantly reduced than the controls (1.28+/-0.37 ng/ml/hr) (P<0.001), the diabetic group with microalbuminuria (1.08+/-0.48 ng/ml/hr) (P<0.05) and normoalbuminuric patients (1.56+/-0.82 ng/ml/hr) (P<0.001). A significant negative correlation was obtained between serum creatinine and plasma renin activity (r=-0.842, p<0.001) in macroalbuminuric NIDDM patients. Plasma angiotensin II was significantly decreased in non-complicated diabetics compared to healthy controls (4.36+/-1.49 pg/ml vs 14.87+/-3.48 pg/ml respectively, p<0.001). Non-insulin dependent diabetic patients with nephropathy had significantly higher plasma angiotensin II levels (28.99+/-5.88 pg/ml) than non-complicated diabetics (p<0.001). Serum ACE activity was increased in 53.3% of NIDDM patients. All diabetic groups showed increased serum ACE activity (normoalbuminuric NIDDM 114.9+/-28.3 nmol/min/ml, microalbuminuric NIDDM 127.9+/-31.2 nmol/min/ml and macroalbuminuric NIDDM 127.0+/-29.3 nmol/min/ml) when compared to the normal control group (76.3+/-16.5 nmol/min/ml) (p<0.001). No significant difference in serum ACE activity was obtained between normoalbuminuric and nephropathic diabetics or between diabetics with and without retinopathy. No significant correlation was obtained between serum ACE activity and blood pressure, blood glucose level and duration of diabetes. Thus plasma renin activity is decreased in diabetic nephropathy and negatively correlates with serum creatinine. Plasma angiotensin II is decreased in normoalbuminuric diabetics and elevated in diabetic nephropathy. Serum ACE activity is raised in NIDDM patients with no relation to albumin excretion rate. The role of increased ACE activity in NIDDM remains to be established.

Adult↗
PubMed2001

Activation of c-Jun NH2-terminal kinase/stress-activated protein kinase (JNK/SAPK) is critical for hypoxia-induced apoptosis of human malignant melanoma.

Mitogen-activated protein kinase (MAPK) signaling was examined in malignant melanoma cells exposed to hypoxia. Here we demonstrate that hypoxia induced a strong activation of the c-Jun NH2-terminal kinase (JNK), also termed stress-activated protein kinase (SAPK), in the melanoma cell line 530 in vitro. Other members of the MAPK family, e.g., extracellular signal-regulated kinase and p38, remained unaffected by the hypoxic stimulus. Activated JNK/SAPK could also be observed in the vicinity of hypoxic tumor areas in melanoma metastases as detected by immunohistochemistry. Functional analysis of JNK/SAPK activation in the melanoma cell line 530 revealed that activation of JNK/SAPK is involved in hypoxia-mediated tumor cell apoptosis. Both a dominant negative mutant of JNK/SAPK (SAPKbeta K-->R) and a dominant negative mutant of the immediate upstream activator of JNK/SAPK, SEK1 (SEK1 K-->R), inhibited hypoxia-induced apoptosis in transient transfection studies. In contrast, overexpression of the wild-type kinases had a slight proapoptotic effect. Inhibition of extracellular signal-regulated kinase and p38 pathways by the chemical inhibitors PD98058 and SB203580, respectively, had no effect on hypoxiainduced apoptosis. Under normoxic conditions, no influence on apoptosis regulation was observed after inhibition of all three MAPK pathways. In contrast to recent findings, JNK/SAPK activation did not correlate with Fas or Fas ligand (FasL) expression, suggesting that the Fas/FasL system is not involved in hypoxia-induced apoptosis in melanoma cells. Taken together, our data demonstrate that hypoxia-induced JNK/SAPK activation appears to play a critical role in apoptosis regulation of melanoma cells in vitro and in vivo, independent of the Fas/FasL system.

Apoptosis↗
PubMed2001

Parental [correction of Perinatal] consanguinity: a risk factor for developmental delay in Pakistani children.

OBJECTIVE: To investigate the association of parental consanguinity and delayed development in terms of gross motor, fine motor, speech and social aspects in their children. METHODS: One hundred and seventy seven children (age 15 days--72 months) were evaluated for their developmental status utilizing the Denver Developmental Screening Test (DDST). An unmatched case-control study design was used. Case group consisted of 94 children and control group 83 children. Odds ratios were calculated for parental consanguinity and delay in gross and fine motor, speech and social development in their children, for cases and controls, utilizing Binary Multiple Logistic Regression Analysis. Acquired delay was excluded through detailed birth history in both cases and control group respectively. RESULTS: Univariate analysis showed high significant Odds ratios for all areas of developmental delay (viz. gross and fine motor, speech and social development), between cases and controls (p < .001). At the multivariate analysis level however, our results showed no increased risk of parental consanguinity on delayed gross and fine motor, speech and social development in their children. CONCLUSION: Our results show no increased risk of parental consanguinity on delayed gross and fine motor, speech or social development (as measured by the DDST), in their children.

Analysis of Variance↗
PubMed2000

Immunophenotypes in adult acute lymphocytic leukemia. Role of flow cytometry in diagnosis and monitoring of disease.

Flow cytometry has revolutionized the study of hematopoietic cells. Immunophenotyping by multiparameter flow cytometry supplements conventional morphologic diagnosis by providing information on cell lineage and differentiation in ALL and helps monitor disease by improving sensitivity in detecting minimal residual disease. The use of multiple MoAbs and multicolor study by flow cytometry has revealed heterogeneity among ALL and mixed-lineage acute leukemia, which are assigned to the same diagnostic categories by morphology. As technology has improved, clinical and research applications of flow cytometry have expanded to include evaluation of nuclear markers, oncogene proteins, apoptosis, cytokine receptors, and drug resistance. Expanded identification of MoAbs against leukemia-specific markers and the use of QFCM be a significant in managing patients with ALL in the future. In addition, flow cytometry and flow cytometric sorting will be combined more and more with other technologies, such as molecular probing or fluorescence in situ hybridization (FISH). The sorting of rare malignant cells based on immunophenotype and subsequent confirmation by PCR or FISH has already been proven feasible. Ultimately, it is hoped that further definition of subgroups of ALL by immunophenotyping using prognostically significant markers and the use of hybrid technologies of flow cytometry and molecular analysis or cytogenetics will improve treatment strategies for patients with ALL.

Adult↗
PubMed2000

Trypanocidal activity of organotin chlorides on Trypanosoma brucei-infected mice.

The organotin compounds dibutyltin (DBTC) and diphenyltin dichlorides (DPTC) were tested for trypanocidal activity on a Trypanosoma brucei-infected mice model. At a dose of 10 mg DBTC and 15 mg DPTC/kg/day for five consecutive days, they cleared the parasites from the peripheral blood of the infected mice. Subinoculation of some healthy mice with the homogenates of liver, spleen, kidney, cerebrospinal fluid and blood from the mice considered cured, showed a few cases of relapse. The LD50 of DBTC and DPTC are 90 mg/kg and 75 mg/kg respectively.

Animals↗
PubMed2000

Clinical pharmacology studies in patients with renal impairment: past experience and regulatory perspectives.

The objective of this report is to provide a regulatory perspective on the quality of pharmacokinetic studies in renal impairment (RI) studies submitted in support of new drug applications (NDAs) or supplements to NDAs (sNDAs) submitted to the Food and Drug Administration (FDA). Fifty-one NDA and 20 sNDA submissions reviewed between 1996 and 1997 by the Office of Clinical Pharmacology and Biopharmaceutics were evaluated for the following: (1) whether an RI study was conducted; (2) contribution of the renal clearance to the overall clearance in subjects without renal impairment; (3) degree of plasma protein binding (%PB) in subjects without renal impairment; (4) dose proportionality of single and multiple doses; (5) study design, including dosing regimen; (6) definition of renal impairment; (7) stratification of renal functions; (8) number of subjects/group; (9) data analysis and interpretation; and (10) impact on labeling. Results of the analysis indicated that 67% of the NDAs and 30% of supplemental NDAs contained RI-studies (34/51 for NDAs and 6/20 for sNDAs). No obvious differences in the pharmacokinetic characteristics (e.g., percentage excreted unchanged in urine and %PB) were observed between drugs for which RI studies were conducted versus those not conducted. Most studies conducted were designed as single dose (70%). Seventy-five percent of the studies used doses within the therapeutic dosage range of the drug. The measured 24-hour creatinine clearance was most often used to assess the renal function. Stratification of renal function ranged from one to five groups, with 6 to 8 subjects enrolled per group. In most studies conducted (38/40), data were analyzed by point estimate using ANOVA. Results of RI studies were adequately reflected in the labeling. The survey reveals that RI study design can be improved for regulatory review purposes. In part based on this analysis, the FDA has prepared a guidance that provides recommendations on the design, analysis, and impact on dosing and labeling for RI studies to include recommendations on when RI studies do not need to be performed. The guidance proposes an equivalence approach with confidence intervals, as opposed to a point estimate approach, to assess the impact of RI on systemic exposure measures.

Attitude of Health Personnel↗
PubMed2000

11q23 abnormalities in patients with acute myelogenous leukemia and myelodysplastic syndrome as detected by molecular and cytogenetic analyses.

11q23 chromosomal abnormalities and rearrangement of the mixed lineage leukemia (MLL) gene are important prognostic factors in acute myelogenous leukemia (AML) and myelodysplastic syndrome (MDS). However, the presence of 11q23 abnormalities does not always correlate with that of MLL gene rearrangement. We retrospectively compared the occurrence of 11q23 abnormalities (measured by karyotyping) and MLL gene rearrangement (measured by Southern blotting) in bone marrow from 311 consecutive adult patients with AML or MDS. 11q23 abnormalities were found in 18 patients (5.8%), of whom 7 (39%) did not have the MLL gene rearrangement. MLL gene rearrangement was detected in 35 patients (11.2%). Of these 35 patients, only 11 (31%) had cytogenetic evidence of 11q23 abnormalities. None of the 21 patients with chronic myelomonocytic leukemia had 11q23 abnormalities or MLL gene rearrangement. 11q23 abnormalities were associated with shorter survival than was a diploid karyotype. Both cytogenetic and molecular studies should be performed to detect 11q23 abnormalities in patients with AML or MDS.

Adolescent↗
PubMed2000

Influence of antipsychotic, antiemetic, and Ca(2+) channel blocker drugs on the cellular accumulation of the anticancer drug daunorubicin: P-glycoprotein modulation.

We investigated the effect of antiemetic, antipsychotic, and Ca(2+) blocker drugs on the function of P-glycoprotein (Pgp) in vitro and compared inhibitory concentrations with therapeutic blood levels. Human colon adenocarcinoma (Caco-2) and human blood-brain barrier endothelial cells were transfected or transduced to express Pgp, and the uptake of rhodamine123, calcein AM, or daunorubicin was measured by flow cytometry in the presence of the drugs. NIH3T3/MDR1 cells were used for reference testing. Results of the flow cytometric studies were supported by cell proliferation and monolayer permeability studies. Thirty-five drugs are included in this study, of which 13 modulate the function of Pgp at the therapeutic blood concentration and 8 at a concentration 2 to 4 times higher. Two drugs, which block the function of Pgp only partially at therapeutic blood concentrations, blocked the function of Pgp completely if used concomitantly. Based on these in vitro experiments, we conclude that administration of several drugs that modulate the function of Pgp simultaneously may adversely affect the natural function of this efflux pump and may cause drug-induced side effects in patients.

3T3 Cells↗
PubMed2000

Osteopoikilosis--a case report.

Osteopoikilosis is a rare, inheritable, sclerosing bone dysplasia; sometimes mistaken for osteoblastic bone metastases. We report a case in a 25 year-old lady.

Adult↗
PubMed2000

HUKM instrumentation system in surgical treatment of adolescent idiopathic scoliosis--an early experience.

Between May 1992 through October 1998, twenty-two patients who had adolescent idiopathic scoliosis were treated using Universiti Kebangsaan Malaysia (UKM) spinal instrumentation and fusion. The minimum length of follow-up was 2 years with an average of 2.9 years. Nineteen patients were female and three patients were male. The mean age at the time of the operation was 16.2 years (range, 13 to 24 years). The average blood loss was 1,878 ml and the average operating time was 291 minutes. The mean pre-operative curve was 61.2 degrees, with a range of 40 degrees to 90 degrees. The average post-operative correction of the Cobb's angle was 53.5 per cent, with a range of 33 per cent to 81 per cent. Post-operative immobilization consisted of a maximum of six months in a body cast. There were no neurological injuries, no deep wound infections, and no evidence of pseudoarthroses. Only three complications occurred and these did not disturb the progress of the fusion. This technique safely achieves the objectives of scoliosis correction, and is cost-effective in the treatment of adolescent idiopathic scoliosis.

Adolescent↗
PubMed2000

Proximal third femoral shaft fractures in children: prevention of angular deformities using bilateral Thomas splints.

This is a prospective study to look at the outcome of unilateral proximal third femoral shaft fractures in children treated with a bilateral Thomas splint in the Department of Orthopaedic Surgery Universiti Kebangsaan Malaysia between the period of January 1996 and June 1998. Eighteen children aged between 2 years and 12 years old with unilateral proximal third fractures of the femoral shaft were treated using a bilateral Thomas splint. Angular deformities were measured using a goniometer metric scale before and after Thomas splints. The percentage of varus tilt corrected ranged from 17% to 72% with an average correction of 29% from the initial deformity and the difference was statistically significant (p < 0.05). The percentage of posterior tilt corrected ranged from 19% to 60% with the average correction of 20% from the initial deformity. The difference was statistically significant (p < 0.05). From this study, we conclude that bilateral Thomas splints can give a better correction of angular deformity for proximal third femoral shaft fractures in children below twelve years of age.

Child↗
PubMed1999

The accuracy of urinary cytology in daily practice.

BACKGROUND: Most studies of urinary cytology have been research analyses designed to test the method itself, and many claim that the high diagnostic yields in these studies cannot be achieved in daily practice. The authors examined the clinical and pathologic records in three hospital pathology practice settings--academic, community, and cancer referral settings--to determine the diagnostic yield of urinary cytology under daily clinical conditions. METHODS: Records of consecutive urinary cytology specimens from 1672 patients reported from the years 1990-1994 were reviewed and correlated with histologic and clinical information. Initial analyses were based on the records themselves, without review of pathologic specimens. Subsequently, a subset of specimens was reviewed to determine reasons for noncorrelations. RESULTS: Results confirmed that the diagnostic sensitivity and specificity of urinary cytology for high grade transitional cell neoplasms, as reported in the daily practice of pathology, are very high (79% and >95%, respectively). Disaggregated cells from low grade transitional cell neoplasms usually lack recognizable features of neoplasia, and attempts to classify such lesions cytologically result in low diagnostic yield, with an overall sensitivity of 26%. Of these 1672 patients, 707 had insufficient clinical information for analysis, despite diligent and persistent efforts to acquire it. CONCLUSIONS: The diagnostic yield of consultations based on urinary cytology in the daily practice of pathology is high, regardless of whether the practice setting is referral-based or community-based. The available information indicates that in approximately 79% of patients with high grade transitional cell neoplasms, the neoplasms can be detected using urinary cytology. Conversely, a negative result is predictive of no cancer in more than 90% of cases. Sensitivity for detecting low grade urothelial lesions is low; however, most of these are easily detected cystoscopically. The authors' inability to acquire sufficient information to determine diagnostic yield in a large percentage of their cases was disturbing to them. Not only did this deficiency render their analyses incomplete, but lack of easily accessible follow-up and the apparent low priority for quality assurance activities among pathologists in all types of practice settings is likely to significantly reduce the feedback required for pathologists to acquire and maintain expertise in this very difficult area.

Carcinoma, Transitional Cell↗
PubMed1999

A new minimally invasive technique to show nerve ischaemia in diabetic neuropathy.

AIMS/HYPOTHESIS: Experimental studies have shown that abnormalities of nerve microcirculation are important factors in the pathogenesis of diabetic neuropathy but there have been few clinical studies. We have applied microlightguide spectrophotometry to measure intravascular oxygen saturation (HbO2%) and blood flow in human sural nerve. METHODS: We studied ten patients with mild-moderate sensory motor diabetic neuropathy, nine patients without neuropathy and nine control subjects. We took 300 measurements of oxygen saturation under direct visual control through a 1.9 mm rigid endoscope over three regions of the nerve. Spectrophotometric measurements of nerve fluorescence were taken after an intravenous injection of sodium fluorescein and the rate of increase in nerve fluorescence (rise time) was used as an indicator of nerve blood flow. RESULTS: Nerve oxygen saturation was reduced in patients with neuropathy compared with control subjects (67.1 +/- 2.2% vs 76.7 +/- 2.1%, p = 0.006). Fluorescein rise time was prolonged in patients with neuropathy compared with the control group (48.5 +/- 7.0 s vs 14.0 +/- 3.1 s, p = 0.001) suggesting impaired nerve blood flow. There was a correlation between rise time, nerve oxygen saturation, glycaemic control and sural nerve sensory conduction velocity (p < 0.01). CONCLUSION/INTERPRETATION: The combination of microlight-guide spectrophotometry and micro-endoscopy provides a valuable minimally invasive technique for clinical investigation of nerve microcirculation. We have shown reduced nerve oxygenation and impaired blood flow in diabetic neuropathy and these findings strongly support a central role of microvascular disease in the pathogenesis of diabetic neuropathy.

Diabetic Neuropathies↗
PubMed1999

Combined microlightguide spectrophotometry and microendoscopy for measurement of oxygen saturation in peripheral nerves.

Microlightguide measurements of the spectral composition of backscattered light may be used to determine local tissue oxygen saturation and monitor tissue perfusion using intravenous injection of fluorescein dye as a contrast agent. We have used a combination of microlightguide spectrophotometry and microendoscopy to measure intravascular oxygen saturation (HbSaO2%) and monitor blood flow in the sciatic nerve of 12 healthy male Sprague-Dawley rats. The microlightguide and endoscope combination is a relatively new measurement technique. The aims of this study were to determine whether microlightguide spectrophotometry and microendoscopy could be used to measure HbO2 and blood flow in peripheral nerves and to compare the measurements made using the flexible lightguide with the endoscope-lightguide combination. We found no significant difference between the two types of measurement over similar regions of the nerve. mean SaO2% values 77.1% (95% CI = 75.4-78.8) and 78.8% (95% CI = 77.5-80.1) respectively. During a period of hypoxia there was a similar fall in both arterial and nerve oxygen saturation. Following injection of fluorescein, the rate of increase in nerve fluorescence was used as a measure of perfusion. The combination of microlightguide spectrophotometry and microendoscopy allows the exact site of measurement to be directly visualized. The minimally invasive nature of this technique may allow its application to the study of peripheral nerves in human subjects in conditions such as diabetic neuropathy where vascular factors are thought to have an important role in aetiology.

Animals↗
PubMed1999

Osteosarcoma in a sixteen-month old boy.

We report a case of a sixteen-month old boy with osteosarcoma of the left humerus. To the best of our knowledge this is the youngest case reported in Malaysia. This case illustrates that osteosarcoma although rare does occur in a very young child. The child died six weeks after presentation due to disseminated disease.

Bone Neoplasms↗
PubMed1998

Prospective, randomized trial comparing pain and complications between diathermy and scissors for closed hemorrhoidectomy.

PURPOSE: The aim of this study was to assess pain and complication rates after closed hemorrhoidectomy with the use of either scissors or diathermy excision. METHODS: Ninety-one consecutive patients were prospectively randomly assigned by use of sealed envelopes to Group A (diathermy dissection; n = 44) or Group B (scissors dissection; n = 47). The resulting hemorrhoidal pedicle after hemorrhoidal dissection was transfixed and buried under the mucosa, which was closed with 3-0 chromic catgut. RESULTS: The median time taken for surgery was ten minutes in both groups. The range for Group A was 5 to 25 minutes, and the range for Group B was 5 to 20 minutes. There were no statistically significant differences in the pain scores between the two groups for any of the seven postoperative days studied. The median number of pethidine injections in Group A was 1 and in Group B was 0 (P < 0.009). The number of oral analgesic tablets used was 8 (range, 4-10) and 14 (range, 0-10) for Groups A and B, respectively (P < 0.001). The number of tubes of topical lignocaine jelly used was 14 (range, 0-22) and 14 (range, 7-88) in Groups A and B, respectively. Two patients in each group developed secondary hemorrhage, but no patient had anal stricturing. CONCLUSION: No excessive complications are seen with closed hemorrhoidectomy, and diathermy seems to require less postoperative analgesic medicine than scissors for closed hemorrhoidectomy except in the first 24 hours.

Adult↗