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Biomedical subjects

N Ansari

Publications and source records attributed to N Ansari.

At least 19 recordsLinked to original sources
PubMed2006

Comparison of RANTES expression in Crohn's disease and ulcerative colitis: an aid in the differential diagnosis?

BACKGROUND: RANTES (regulated on activation, normal T cell expressed and secreted) expression is increased in inflammatory bowel disease (IBD). RANTES is produced at higher levels in granulomatous conditions, so increased RANTES expression can be expected in Crohn's disease compared with ulcerative colitis. AIM: To compare RANTES expression between intestinal biopsy specimens of patients with Crohn's disease and those with ulcerative colitis. MATERIALS AND METHODS: A prospective study of patients presenting with lower gastrointestinal symptoms at the Bahrain Specialist Hospital from July 2004 to April 2005 was carried out. Endoscopic colonic biopsy specimens were taken from every patient and subjected to (a) routine haematoxylin and eosin staining examination by light microscopy, (b) immunohistochemistry for examination of RANTES protein expression by light microscopy and (c) in situ hybridisation for examination of RANTES mRNA expression by light microscopy. RANTES expression was assessed and quantified. RESULTS: 58 patients were enrolled to the study. Of them, 40 had IBD (21 had Crohn's disease and 19 had ulcerative colitis), 15 were controls with normal colonic biopsy results or non-inflammatory lesions and 3 had colonic inflammatory lesions other than IBD. RANTES expression in lymphocytes or histiocytes was significantly higher (p = 0.04) in new patients with ulcerative colitis than in those with Crohn's disease analysed by immunohistochemistry (IHC). CONCLUSION: RANTES expression in lymphocytes or histiocytes is significantly higher in patients with ulcerative colitis than in those with Crohn's disease. Hence, RANTES IHC can be an effective method for distinguishing between biopsy specimens of patients with ulcerative colitis from those of patients with Crohn's disease, where routine histological features are indeterminate. RANTES IHC may prove to be a useful technique for identifying early or equivocal granulomas.

Biomarkers↗
PubMed2002

Clinical characteristics of pruritus in chronic idiopathic urticaria.

BACKGROUND: Although pruritus is a predominant symptom of chronic idiopathic urticaria (CIU) its clinical characteristics have not been explored. OBJECTIVES: To characterize the clinical pattern and sensory and affective dimensions of the itch experience, utilizing a comprehensive itch questionnaire. METHODS: A structured questionnaire based on the McGill pain questionnaire was used in 100 patients suffering from CIU randomly recruited from a tertiary referral centre. RESULTS: All 100 patients recruited with CIU completed the questionnaire. In 68 patients pruritus appeared on a daily basis. Most patients experienced their pruritus at night and in the evening (n = 83), and 62 reported difficulty in falling asleep. Pruritus involved all body areas, but mostly the arms (n = 86), back (n = 78) and legs (n = 75). Accompanying symptoms were a sensation of heat in 45 patients and sweating in 15. Most patients (n = 98) were prescribed antihistamines (mainly sedating), of whom 34 experienced long-term relief. The sensation of itch was reported to be stinging (n = 27), tickling (n = 25) and burning (n = 23). Seventy-six patients found their pruritus bothersome, 66 annoying and 14 complained of depression. The itch intensity at its peak was more than double that felt after a mosquito bite. The worst itch scores of those who felt depressed were significantly higher than of those who did not (P = 0.018). There was a positive correlation between the sensory and affective scores during worst itch (P < 0.001). CONCLUSIONS: This study describes the itch experienced in CIU, highlighting sensory and affective dimensions. The itch questionnaire was found to be a valuable tool for evaluating pruritus in CIU and its unique features.

Activities of Daily Living↗
PubMed2001

Symptomatic atrial arrhythmias in hemodialysis patients.

BACKGROUND/AIMS: Cardiac arrhythmias are frequent in hemodialysis patients and can interrupt treatment. However, the frequency and risk factors have remained unclear because previous reports of arrhythmias in dialysis patients have usually been continuous-monitoring studies that looked at all cardiac ectopy regardless of its seriousness. METHODS: We reviewed retrospectively only symptomatic atrial arrhythmias in a population of 106 maintenance hemodialysis patients over three years, in order to estimate their actual frequency and any risk factors. RESULTS: Ten patients, seven men and three women, required treatment for atrial arrhythmias (9.4%): four for supraventricular tachycardia, three for atrial flutter, and three for atrial fibrillation. Their mean age was 53.7 +/- 6.1 years; five of them were < or = 40 years. Seven arrhythmias were new, three were recurrences. All but one occurred between 3 and 4 hours of hemodialysis, and dialysis had to be stopped in nine instances. There was no pattern of hypotensive episodes preceding the arrhythmias. Mean serum K+ drawn at the time of the arrhythmias was 3.8 +/- 0.2 mEq/L. Mean plasma intact parathormone was 1128 +/- 417 pg/mL, compared to 454 +/- 58 pg/mL for our entire hemodialysis population (p = .0036). Subsequent echocardiograms showed abnormalities in 9/10 patients: five had left ventricular hypertrophy, six had left atrial enlargement, five had valvular lesions (four mitral regurgitation; one aortic incompetence), and three had ejection fractions <50%. There were four deaths in these patients over the next 14 months, but probably only one was cardiac. CONCLUSIONS: Serious atrial arrhythmias are common in a hemodialysis population. Risk factors for symptomatic atrial arrhythmias in hemodialysis patients may include hyperparathyroidism and echocardiographic findings of chamber enlargement, valvular lesions, or ventricular dysfunction.

Atrial Fibrillation↗
PubMed2001

Eccrine porocarcinoma (malignant eccrine poroma): a clinicopathologic study of 69 cases.

The clinicopathologic characteristics of 69 cases of eccrine porocarcinoma (EP) have been studied. Seven cases of purely in situ disease are included. Forty patients were female, 29 male with ages ranging from 29 to 91 years (mean 73 years). The lower extremity represented the single most common site (44%). Other common sites were the trunk (15 cases, 24%) and head (11 cases, 18%). The histologic diagnosis of EP was predicated on the basis of an irregular tumor at least partly formed of characteristic poromatous basaloid epithelial cells displaying ductal differentiation, and significant cytologic atypia. Forty-seven tumors (68%) contained mature well-formed eccrine ducts having an eosinophilic luminal cuticle, with the remaining tumors containing small ill-formed ducts and/or intracytoplasmic lumina. All ducts were discernible via light microscopy and in 49 cases were highlighted with DPAS stain and/or CEA/EMA immunocytochemistry. A variant with a broad pushing tumor margin and marked nuclear pleomorphism showed some resemblance to proliferative bowenoid dysplasia. In 11 cases (18%) the tumors appeared to arise in continuity with a benign preexistent poroma. A variety of histologic patterns were displayed including clear, squamous, and spindle cell differentiation, mucus cell metaplasia, and colonization by melanocytes. Lymphovascular invasion was present in 9 cases (15%). Three cases showed pagetoid extension of malignant cells (epidermotropism) and appeared to be multifocal. Follow-up was available in 54 patients (78%) with 9 (17%) experiencing local recurrence, 10 developing lymph node metastases (19%), and 6 (11%) experiencing distant metastases or death. Mitoses, the presence of lymphovascular invasion, and tumor depth >7 mm were associated with a poorer prognosis. Dividing tumors into those with a "pushing" or "infiltrating" advancing margin was also predictive of outcome with the latter having an increased risk of local recurrence. This report, the largest series of EP to date, suggests that the incidence of aggressive behavior is less than popularly believed. Furthermore, EP can display a wide variety of histologic patterns that may lead to diagnostic error in the unwary. The large number of cases in this series enables a reliable evaluation of prognostic parameters. A more aggressive clinical course may be indicated by more than 14 mitoses per high power field (hazard ratio [HR] for death 17.0, 95% confidence interval [CI] 2.71-107), lymphovascular invasion by tumor (HR 4.41, CI 1.13-17.2), and depth >7 mm (HR 5.49, CI 1.0-30.3). Thus, mitoses, lymphovascular invasion, and tumor depth should be evaluated in these tumors. We also suggest that tumors presenting an "infiltrative" advancing margin are particularly prone to local recurrence and require wide excision with close attention to the surgical margins by the reporting pathologist.

Acrospiroma↗
PubMed1999

Tubulointerstitial nephritis associated with minimal self reexposure to rifampin.

We report the case of a 27-year-old Asian man who self-medicated with two capsules of rifampin 1 year after completing a continuous course of chemotherapy for tuberculosis that included that drug. He developed flank pain and edema and presented with uremia requiring dialysis; despite this, he had a serum potassium of only 3.5 mEq/L. Renal biopsy showed interstitial infiltrate with inflammation of the tubules. Renal function began to improve after a 3-week course of prednisone. This case is remarkable for the severity of the renal failure despite such a minimal self-exposure.

Acute Disease↗
PubMed1998

Stress response and mode of ventilation in preterm infants.

AIM: To assess the change in stress response in preterm babies changed from patient triggered ventilation (PTV) to conventional mandatory ventilation (CMV) and vice versa; to determine outcome in relation to stress hormone concentrations. METHODS: A randomised controlled study was conducted in two district general hospital neonatal intensive care units. Thirty babies, treated initially with CMV, were randomly assigned to remain on CMV or to change to PTV. A second group of 29 babies, treated initially with PTV, were randomly assigned to remain on PTV or to change to CMV. The babies were less than 32 weeks of gestation, ventilated within 72 hours of birth, with clinical and radiological features compatible with respiratory distress syndrome (RDS). Stress hormone concentrations and clinical distress score were measured before and 20 minutes after allocation of mode of ventilation. RESULTS: Babies changed from CMV to PTV had significantly reduced adrenaline concentrations (median change -0.4 nmol/l) compared with those who remained on CMV. There was no increase in adrenaline in babies changed from PTV to CMV. There were no significant changes in noradrenaline concentrations or clinical distress score. Babies who died had significantly higher adrenaline and noradrenaline concentrations than those who survived. CONCLUSION: A change in mode of ventilation significantly reduces adrenaline concentrations. Raised catecholamine values are associated with a poor outcome.

Epinephrine↗
PubMed1998

Cisplatin induces N-acetyl cysteine suppressible F2-isoprostane production and injury in renal tubular epithelial cells.

In the low intracellular chloride milieu, chloride ions of cisplatin may exchange for cellular SH moieties resulting in glutathione depletion, H2O2 accumulation, and lipid peroxidation. Cisplatin-induced lipid peroxidation, in addition to causing direct cellular injury, may further contribute to cisplatin-induced renal dysfunction by generating vasoconstrictive E2- and F2-isoprostanes. The aim of this study was to determine whether cisplatin-induced renal epithelial (LLC-PK1 and primary human proximal tubular) cell injury is associated with increased production of isoprostanes, and whether this can be suppressed with a thiol donor, N-acetyl cysteine. It was confirmed that incubation of renal epithelial cells with cisplatin resulted in N-acetyl cysteine-inhibitable glutathione depletion, H2O2 accumulation, lipid degradation, and lactate dehydrogenase release. In additional experiments, incubation of cells with cisplatin for 48 h was accompanied by a dose-related increase in total (free plus esterified) F2-isoprostanes. An increase in F2-isoprostanes was discernible at 16.5 microM cisplatin and doubled at 66.0 microM. N-Acetyl cysteine at 50 microM concentration effectively suppressed 66.0 microM cisplatin-induced increase in isoprostanes. Similar findings were also obtained in human cells. Thus, cisplatin-induced tubular cell injury is accompanied by increased isoprostane production through a mechanism involving thiol depletion. On the basis of this new finding, it is hypothesized that these arachidonic acid peroxidation products may be partially responsible for the cisplatin-induced renal vasoconstriction demonstrable in the in vivo models.

Acetylcysteine↗
PubMed1995

Biochemical factors in the lens opacities. Case-control study. The Lens Opacities Case-Control Study Group.

OBJECTIVE: To evaluate associations with biochemical indicators of nutritional and other risk factors in the Lens Opacities Case-Control Study. DESIGN: Case-control study. SETTING AND PARTICIPANTS: The Lens Opacities Case-Control Study determined risk factors for cortical, nuclear, and posterior subcapsular opacities among 1380 participants aged 40 to 79 years. DATA COLLECTION: Vitamin E, selenium, and biochemistry profile determinations were performed on all patients; red blood cell enzymes and amino acids were measured in systematic samples of about 25% of the Lens Opacities Case-Control Study population. OUTCOME: Laboratory test values in cases and controls were compared and expressed as odds ratios and 95% confidence intervals. RESULTS: In polychotomous logistic regression analyses controlling for age and sex, the risk of opacities was reduced to less than one half in persons with higher levels of vitamin E (odds ratio, 0.44 for nuclear opacities), albumin-globulin ratio (odds ratio, 0.41 for mixed opacities), or iron (odds ratio, 0.43 for cortical opacities); higher uric acid levels increased risk (odds ratio, 1.74 for mixed opacities). Persons with opacities were twice as likely to have high glutathione reductase activity (with flavin adenine dinucleotide), which suggests low riboflavin status (odds ratio, 2.13). Most odds ratios for amino acids were under unity and were significantly decreased for glycine (0.36) and aspartic acid (0.31). CONCLUSIONS: Lens opacities were associated with lower levels of riboflavin, vitamin E, iron, and protein nutritional status. Higher levels of uric acid increased risk of mixed opacities. The findings for riboflavin, vitamin E, iron, and uric acid are compatible with the dietary intake and medical history results of the Lens Opacities Case-Control Study.

Adult↗
PubMed1992

Binding of the EcoRII methyltransferase to 5-fluorocytosine-containing DNA. Isolation of a bound peptide.

The properties of the interaction of 5-fluorocytosine-containing DNA with the EcoRII methyltransferase were studied. The DNA used was either a polymer synthesized in vitro, or a 20-mer containing one CCA/TGG sequence. The DNA could be methylated by the enzyme. In the process the enzyme formed a tight binding adduct with the DNA that could be identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Enzyme activity was inhibited by this interaction. The 20-mer could be used to titrate the active site of the enzyme. The DNA polymer formed a tight binding complex that could be identified following digestion of the DNA with pancreatic deoxyribonuclease or micrococcal nuclease. A peptide-DNA adduct could be isolated after digestion of the EcoRII-DNA adduct with staphylococcal protease V8 by high pressure liquid chromatography and polyacrylamide gel electrophoresis. Sequencing of the peptide indicated the DNA bound to a region of the protein that is conserved in all procaryotic DNA(cytosine-5)-methyltransferases. We have previously shown that this region contains a cysteine that can be photomethylated with adenosylmethionine. This region, in addition to forming part of, or being adjacent to, the AdoMet binding site, also forms part of the DNA binding site.

Amino Acid Sequence↗
PubMed1992

The actions of endothelins-1 and -3 on the vascular and capsular smooth muscle of the isolated blood perfused spleen of the dog.

1. Endothelin-1 (ET-1), endothelin-3 (ET-3) and noradrenaline (NA) were administered as intra-arterial bolus injections into the isolated, blood-perfused spleen of the dog to assess agonist properties and relative molar potencies on the vascular and capsular smooth muscle. 2. An initial small vasodilatation was observed occasionally at low doses (1.0-10 pmol) of ET-1. 3. ET-1, ET-3 and NA all caused graded increases in splenic arterial vascular resistance. The molar ED50 for the splenic vasoconstrictor response to ET-1 was significantly less (P less than 0.001) than that to ET-3; both peptides were significantly more potent as vasoconstrictor agents than NA. The maximum increase in splenic arterial vascular resistance was not significantly different for either ET-1, ET-3 or NA. 4. The time course of the splenic vasoconstrictor response to ET-1 was significantly (P less than 0.01) longer than that to equieffective doses of ET-3 or NA. 5. The splenic vasoconstrictor responses to ET-1 and ET-3 were accompanied by reductions in spleen volume. The rank order of molar potency in causing splenic capsular contraction was ET-1 greater than ET-3 greater than NA. The maximum reduction in splenic volume was significantly greater for NA than for either ET-1 or ET-3. The two peptides (ET-1, ET-3) were equiefficacious in contracting splenic capsular smooth muscle. 6. The high molar potency of ET-1 as a splenic arterial vasoconstrictor, over 1,700 times more potent than NA, suggests that it may play an important local role in the control of splenic haemodynamics.

Animals↗
PubMed1989

A comparison of glutathione reductase and glutathione peroxidase activities in patients with rheumatoid arthritis and healthy adults.

A 30% increase in erythrocyte glutathione peroxidase (GP) activity was found in patients with rheumatoid arthritis when compared with healthy controls (p = 0.001) whereas the increase in glutathione reductase (GR) was statistically insignificant. No correlation was found between the activities of the enzymes and the erythrocyte sedimentation rate (ESR). The enzyme activities were independent of age, sex, or type of drug treatment of the patients. A possible interpretation of the results is presented.

Adult↗