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Biomedical subjects

A Hussain

Publications and source records attributed to A Hussain.

At least 55 records · Page 3Linked to original sources
PubMed2001

Current diet and colorectal adenomas: a case-control study including different sets of traditionally chosen control groups.

High intake of fat and a low intake of foods rich in antioxidants and fibre are suggested to be associated with risk of colorectal adenomas. Inconsistency may, however, be due to dietary assessment problems or differences in the identification of cases and controls. We have compared 87 adenoma cases aged 50-76 years with 35 healthy controls and 35 'hospital' controls. All the controls were matched for sex and age (+/-5 years) and proven to be free of polyps. Current habitual diet was measured by a 5-day dietary record by weighing. Regarding the intakes of vegetable fat, protein, cholesterol, vitamin A, total vitamin D, edible fats, coffee and fish and fish products, the outcomes of the analysis depended upon the source of controls. However, an increased adenoma risk compared with either set of controls related to a low consumption of vegetables, cereals, iron, vitamin C and fibre and a high intake of total fat was found. This is suggestive of substantial differences, since bias due to abdominal symptoms, the dietary records or an inappropriate choice of controls, would have affected the estimations. The findings give further strength to the role of these dietary factors in the formation of precancerous lesions in the large intestine.

Adenoma↗
PubMed2001

Infliximab for refractory ulcerative colitis.

Eight patients with active ulcerative colitis (UC), refractory to usual combination medical therapy, were treated with a single i.v. dose of chimeric monoclonal antibody to recombinant human tumor necrosis factor alpha; many of these patients were scheduled for surgical colectomy because of their active disease. All patients responded extremely well to a single 5 mg/kg infusion of infliximab, with marked improvement after the infusion clinically, colonoscopically, and histologically on colonic biopsy. There were no significant complications or side effects; mean duration of remission has not been determined because none of the patients have relapsed. Infliximab appears to be a potent agent for inducing remission in refractory patients with ulcerative colitis.

Adult↗
PubMed2001

HIV seroprevalence and its associations with the other reproductive tract infections in asymptomatic women in Harare, Zimbabwe.

The objective was to determine the magnitude of HIV as well as the associations between HIV seropositivity with reproductive tract infections (RTIs) among healthy women in Harare, Zimbabwe. In a cross-sectional study, 393 informed consenting women aged 15--49 years, attending 2 primary healthcare clinics, were interviewed and screened for HIV and RTIs. HIV seroprevalence was 29.3%. Seropositivity was significantly associated with bacterial vaginosis, syphilis, gonorrhoea and/or Chlamydia trachomatis infection, warts and genital ulcers. Risk factors for HIV were absence of lactobacilli in vaginal fluid, vaginal pH >4.5, age >20 years, being unmarried, having had more than one lifetime sexual partner, having used a condom at least once in their lifetime, having experienced an infant mortality, and a partner who was non-monogamous or a frequent traveller. In view of the very high seroprevalence and concomitant RTIs in this population, we recommend promotion of women-controlled prevention methods along with proactive detection and treatment of RTIs.

Adolescent↗
PubMed2001

Posterior lumbar interbody fusion for revision disc surgery: review of 50 cases in which carbon fiber cages were implanted.

OBJECT: The authors undertook a study to assess the value of posterior lumbar interbody fusion (PLIF) in which carbon fiber cages (CFCs) were placed in patients undergoing revision disc surgery for symptoms suggesting neural compression with low-back pain. METHODS: The authors followed their first 50 patients for a maximum of 5 years and a minimum of 6 months after implantation of the CFCs. Patients in whom magnetic resonance (MR) imaging demonstrated "simple" recurrent herniation did not undergo PLIF. Surgery was performed in patients with symptoms of neural root compression, tension signs, and back pain with focal disc degeneration and nerve root distortion depicted on MR imaging compatible with clinical signs and symptoms. In 40 patients (80%) pedicle screws were not used. Clinical outcome was assessed using the Prolo Functional Economic Outcome Rating scale. Fusion outcome was assessed using an established classification. Symptoms in 46 patients (92%) improved after surgery, and given their outcomes, 45 (90%) would have undergone the same surgery again. Two thirds of patients experienced good or excellent outcomes (Prolo score > or = 8) at early and late follow up. There was no difference in clinical outcome between those in whom pedicle screws were and were not implanted (p = 0.83, Mann-Whitney U-test). The fusion rate at 2 years postsurgery was 95%. There were minimal complications, and no patients fared worse after surgery. No patient has undergone additional surgical treratment of the fused intervertebral space. CONCLUSIONS: In this difficult group of patients the aim remains to improve symptoms but not cure the disease. A high fusion rate is possible when using the CFCs. Clinical success depends on selecting patients in whom radiological and clinical criteria accord. Pedicle screws are not necessary if facet joints are preserved, and high fusion rates and clinical success are possible without them.

Adult↗
PubMed2001

Determinants of reproductive tract infections among asymptomatic women in Harare, Zimbabwe.

OBJECTIVES: To determine the prevalence of and risk factors for reproductive tract infections (RTI) among asymptomatic women attending primary health care clinics in Harare, Zimbabwe. DESIGN: A cross sectional study. MAIN OUTCOME MEASURES: Prevalent RTI, HIV and socio-demographic data. SETTING: Two primary health care clinics in Harare. SUBJECTS: 393 consecutive, consenting women aged 15 to 49 years, presenting at the clinics for antenatal care, family planning, or bringing their children to attend preventive care clinics. RESULTS: More than half of the women had at least one ongoing RTI. Voluntary reporting of symptoms was almost non-existent. Prevalence of HIV was 29.3% and that of classical STIs was 15.4% Trichomoniasis vaginalis, 3.9% syphilis, 3.9% Chlamydia trachomatis and 1.8% Neisseria gonorrhoea. Bacteria vaginosis was diagnosed in 30.3% of the women and candidiasis in 25.4%. Presence of any RTI was significantly associated with lower level of education, sexual debut < 20 years, a non-monogamous partner, and use of a condom during the last sexual encounter. Independent factors associated with cervical infections were young age (< 20 years), being unmarried, current dysuria, warts, clinical signs of purulent or yellowish discharge, lower abdominal pain and cervical friability. Vaginitis was associated with sexual debut or marriage < 20 years, a partner who was a frequent traveller, history of STI, and presence of abnormal vaginal discharge. CONCLUSION: In view of the high prevalence of RTI and HIV and the low reporting of symptoms by infected women, it is recommended that strategies that improve women's awareness of urogenital symptoms be adopted, along with pro-active inquiry of genital symptoms by the health care workers, and treatment of RTIs, in order to reduce the unnecessary burden of RTIs.

Adolescent↗
PubMed2001

Patent foramen ovale in elderly stroke patients.

The aim of this study was to determine the incidence of echocardiographically detectable patent foramen ovale (PFO) in elderly patients who have strokes from cerebral infarction, as well as to assess the association between PFOs and other risk factors for stroke disease. Forty-three patients aged > or = 65 years admitted consecutively with cerebral infarction shown on computerised tomography of the brain were assessed using transoesophageal echocardiography. A PFO was present in 8 (19%) of the 43 patients. Four patients (50%) in this PFO group had stroke risk factors. Two were in atrial fibrillation and, of the six patients in sinus rhythm, a risk factor was present in two, both of whom had diabetes mellitus. A PFO was not detected in 35 patients. Twenty-nine (83%) of the patients in this group had risk factors, with 18 having two or more. Seven patients were in atrial fibrillation. Of the 28 patients in sinus rhythm, risk factors were present in 22 (78%).

Aged↗
PubMed2000

[The role of TNF-alpha in myelodysplastic syndrome: immunoserologic and immunohistochemical studies] .

TNF alpha is a highly active cytokine which plays an important role in the regulation of apoptotic cell death, a mechanism involved in the pathophysiology of myelodysplastic syndrome (MDS). In this study we investigated the expression of TNF alpha on the bone marrow trephine biopsies by immunohistochemical method and the TNF alpha production of peripheral blood mononuclear cells by ELISA method in 15 patients affected by MDS. Five of seven patients without excess of blasts showed high or intermediate TNF alpha expression in the bone marrow biopsies, whereas two patients with excess of blasts were negative and one had low expression. The five CMML patients revealed low or intermediate expression. The production of TNF alpha by the PBMC was analysed in 10 patients, four patients with RA and two with CMML produced higher level of TNF alpha which increased after stimulation with phorbol myristic acetate, but none of the RAEB patients revealed increase in TNF alpha production. In conclusion we suppose that increased TNF alpha expression and production by PBMC may be a further indirect evidence of the role of increased apoptosis in low risk MDS patients, in the course of progression the cytokine expression and production decreases.

Adult↗
PubMed2000

Respiratory pacemaker cells responsive to CO(2) in the upper medulla: dose response and effects of mediators.

We previously reported on the presence of respiratory pacemaker cells that are highly sensitive to CO(2), in a region of the medulla oblongata in the fetal rat, 2 mm rostral to the obex. We now report on the CO(2) dose responses of these cells, as well as their responsiveness to certain chemical agents known to affect breathing in the fetus. Twenty-day-old fetal Sprague Dawley rats were block-dissected, and the cells of target areas were dissociated as previously described. Neuronal cells were plated on a medullary background and placed in the incubator with 10% CO(2) for 2-3 weeks. Cells were then studied using patch-clamp techniques. Pacemaker cells with single or bursting potentials showed responsiveness to CO(2) starting with pulses of 10 msec. Irregular beating or silent cells had poor or absent responsiveness to CO(2). Pacemaker cells responded to norepinephrine with increased firing potential; this action was blocked by metropolol. PGE(2) had no effect on pacemaker-cell activity, but indomethacin increased the spike frequency from 336+/-41 to 384+/- 65 spikes/min. Morphine stimulated the pacemaker cells from 205+/-25 to 272+/-29 spikes/min; this was blocked by naloxone. Finally, a placental extract, which inhibited breathing in the unanesthetized fetal sheep preparation, increased the activity of pacemaker cells from 301+/-35 to 452+/-52 spikes/min. In all of the above, irregular beating cells responded poorly and silent cells did not respond. The findings indicate that these pacemaker cells are uniquely designed to respond to CO(2) and have some properties which allow them to respond to certain chemical mediators in a manner similar to that of the whole respiratory system in vivo.

Animals↗
PubMed2000

Detection of TNFalpha expression in the bone marrow and determination of TNFalpha production of peripheral blood mononuclear cells in myelodysplastic syndrome.

TNFalpha is a highly active cytokine which plays an important role in the regulation of apoptotic cell death, a mechanism involved in the pathophysiology of myelodysplastic syndrome (MDS). In this study we investigated the expression of TNFalpha of the bone marrow trephine biopsies by immunohistochemical method and the TNFalpha production of peripheral blood mononuclear cells by ELISA method in 15 patients affected by MDS. Five of seven patients without excess of blasts showed high or intermediate TNFalpha expression in the bone marrow biopsies, whereas two patients with excess of blasts were negative and one had low expression. The five CMML patients revealed low or intermediate expression. The production of TNFalpha by the PBMC was analysed in 10 patients, four patients with RA and two with CMML produced higher level of TNFalpha which increased after stimulation with phorbol myristic acetate, but none of the RAEB patients revealed increase in TNFalpha production. In conclusion we suppose that increased TNFalpha expression and production by PBMC may be an indirect evidence of the role of increased apoptosis in low risk MDS patients.

Adult↗
PubMed2000

The prevalence, classification and treatment of mental disorders among attenders of native faith healers in rural Pakistan.

BACKGROUND: Although native faith healers are found in all parts of Pakistan, where they practice in harmony with the cultural value system, their practice is poorly understood. This study investigated the prevalence, classification and treatment of mental disorders among attenders at faith healers. METHOD: The work of faith healers with 139 attenders was observed and recorded. The mental status of attenders was assessed using a two-stage design: screening using the General Health Questionnaire followed by diagnostic interview using the Psychiatric Assessment Schedule. RESULTS: The classification used by faith healers is based on the mystic cause of disorders: saya (27%), jinn possession (16%) or churail (14%). Sixty-one percent of attenders were given a research diagnosis of mental disorder: major depressive episode (24%), generalized anxiety disorder (15%) or epilepsy (9%). There was little agreement between the faith healers' classification and DSM-IIIR diagnosis. Faith healers use powerful techniques of suggestion and cultural psychotherapeutic procedures. CONCLUSIONS: Faith healers are a major source of care for people with mental health problems in Pakistan, particularly for women and those with little education. Further research should assess methods of collaboration that will permit people with mental health problems to access effective and culturally appropriate treatment.

Female↗
PubMed2000

No difference in serum sialic acid in type 2 diabetic patients from the United Arab Emirates with and without diabetic retinopathy.

Serum total sialic acid (TSA) has recently been shown to be related to diabetic retinopathy. However, there is some controversy as this may be true in European Type 2 diabetic patients but not South Asians. There are few data looking at serum TSA expression in Arab Type 2 diabetic patients from the United Arab Emirates (UAE) and we wished to test the hypothesis that there may be different serum TSA expression in Arab Type 2 diabetic patients as regard to retinopathy. Sixty-five Type 2 diabetic patients from the UAE were studied (19 male and 46 female, age 57.5+/-9.8 (45-74) years, duration of diabetes 9.4+/-5.7 (0-22) years. The serum TSA in 13 patients with diabetic retinopathy was 757+/-130 mg/l and 782+/-163 mg/l in those without retinopathy (NS). There was no significant correlation between serum TSA and patient age, serum fructosamine, diabetes duration, or blood pressure. As in South Asians serum TSA does not appear to be elevated in Type 2 diabetic patients from the United Arab Emirates with diabetic retinopathy.

Aged↗
PubMed2000

The effect of gelatin cross-linking on the bioequivalence of hard and soft gelatin acetaminophen capsules.

PURPOSE: To determine if changes in the in vitro dissolution of hard and soft gelatin acetaminophen capsules, which result from gelatin crosslinking, are predictive of changes in the bioavailability of the capsules in humans. METHODS: Both hard and soft gelatin capsules were "stressed" by a controlled exposure to formaldehyde, resulting in unstressed, moderately stressed and highly stressed capsules. In vitro dissolution studies were conducted using water or SGF with and without pepsin as the media. Separate 24-subject, 3-way crossover human bioequivalence studies were performed on the unstressed and stressed acetaminophen capsules. Plasma acetaminophen was determined by high performance liquid chromatography (HPLC) for 12 hr after each dose. RESULTS: The in vitro rate of dissolution of hard and soft gelatin capsules was decreased by crosslinking. The bioequivalence studies showed that both hard and soft gelatin capsules, which failed to meet the USP dissolution specification in water, but complied when tested in SGF containing pepsin, were bioequivalent to the unstressed control capsules. The capsules that were cross-linked to the greatest extent were not bioequivalent to the unstressed control capsules, based on Cmax. A trend toward an increase in Cmax with increased level of cross-linking was observed, but this was only significant for the severely stressed capsules. CONCLUSIONS: On the basis of this study a two-tier in vitro dissolution test was developed using enzymes to distinguish between bioequivalent and bioinequivalent gelatin capsules.

Acetaminophen↗
PubMed2000

Enhancement of the systemic and CNS specific delivery of L-dopa by the nasal administration of its water soluble prodrugs.

PURPOSE: To study the utility of the nasal route for the systemic delivery of L-dopa using water soluble prodrugs of L-dopa and to examine if this delivery method will result in preferential delivery to the CNS. METHODS: Several alkyl ester prodrugs of L-dopa were prepared and their physicochemical properties were determined. In vitro hydrolysis rate constants in buffer, rat plasma, rat brain homogenate, rat CSF, and rat nasal berfusate were determined by HPLC. In vivo nasal experiments were carried out in rats. Levels of L-dopa and dopamine in plasma, CSF, and olfactory bulb were determined using HPLC method with electrochemical detection. RESULTS: All the prodrugs showed improved solubility and lipophilicity with relatively fast in vitro conversion in rat plasma. Absorption was fast following nasal delivery of the prodrugs with bioavailability around 90%. Dopamine plasma levels did not change significantly following nasal administration of the butyl ester prodrug. Olfactory bulb and CSF L-dopa concentration were higher following nasal delivery of the butyl ester prodrug compared to an equivalent intravenous dose. CONCLUSIONS: Utilization of water soluble prodrugs of L-dopa via the nasal route in the treatment of Parkinson's disease may have therapeutic advantages such as improved bioavailability, decreased side effects, and potentially enhanced CNS delivery.

Administration, Intranasal↗
PubMed2000

In vitro effects of sildenafil and phentolamine, drugs used for erectile dysfunction, on human sperm motility.

OBJECTIVE: The aim of this study was to determine the effects of sildenafil and phentolamine on sperm motility in vitro. STUDY DESIGN: Semen or washed sperm was mixed with various doses of sildenafil or phentolamine and analyzed for motility during a 30-minute period. The pH was measured for each of the samples tested. Statistical analyses were performed with analysis of variance. RESULTS: A 200-microg/mL dose of sildenafil had no effect on sperm motility. However, the highest dose (2000 microg/mL) significantly reduced motility by about 50%. The pH was reduced in this high-dose sample. The lowest dose of phentolamine (20 microg/mL) had no effect, whereas a dose of 200 microg/mL resulted in a significant reduction in sperm motility. The highest dose (2000 microg/mL) stopped virtually all sperm from moving. CONCLUSION: This study demonstrated a direct dose-related effect of phentolamine on reducing sperm motility. Only the highest dose of sildenafil had an effect, which may have been caused by a decline in pH.

Dose-Response Relationship, Drug↗
PubMed2000

A study of breathing pattern and ventilation in newborn infants and adult subjects.

Experimentally modified breathing pattern in human subjects, by varying the inspired gas mixture or administering different neuromodulators, has been studied extensively in the past, yet unmodified breathing has not. Moreover, most data refer to infants during sleep and adults during wakefulness. We studied the baseline breathing pattern of preterm infants [n = 10; GA 30 (27-34) wk (median, range)]; term infants [n = 10; GA 40 (39-41) wk)], and adult subjects [n = 10; age 31 (17-48) y)] during quiet sleep. A flow-through system was used to measure ventilation. We found: (i) instantaneous ventilation was 0.273+/-0.006, 0.200+/-0.003, and 0.135+/-0.002 L x min(-1) x kg(-1) in preterm, term infants, and adult subjects; the coefficients of variation were 39%, 25%, and 14% (p < 0.01). The greater coefficient of variation in neonates compared to adults related to increased variability in Vt (39% and 25% in preterm and term infants vs 14% in adults; p < 0.01) and f (39% and 22% vs 9%; p < 0.01). The major determinant of frequency in preterm infants was Te (81% variability), Ti varying less (25% variability); (ii) V(T)/Ti decreased and Ti/Ttot increased with age; (iii) the higher breath-to-breath variability in preterm infants was associated with larger changes in alveolar PCO2 and a larger variability in O2 saturation than later in life.

Adolescent↗
PubMed2000

Effects of cardiac glycosides on atrial contractile dysfunction after short-term atrial fibrillation.

BACKGROUND: Despite a long history of use in the treatment of paroxysmal atrial fibrillation (AF), the efficacy of cardiac glycosides has not been established. If such drugs are beneficial in this condition, the general view is that the benefit must be related to their inotropic actions. METHODS AND RESULTS: To assess the effects of the rapid-acting cardiac glycoside, acetylstrophanthidin (AS), on AF and AF-induced right atrial (RA) "stunning," RA wall motion (with ultrasonic crystals), RA pressure, and peak first derivative of pressure (dp/dt) (with microtip transducers) were measured before and after 5 min of high-intensity rapid atrial stimulation (10 Hz; 10 mA; 1 ms) and after the cessation of poststimulation AF. Measurements were made in neurally intact and autonomically blockaded dogs both before and after the administration of AS (0.01 mg/kg IV bolus and 0.015 mg/kg/h IV infusion). AS prevented the post-AF reduction in RA peak dp/dt under neurally intact and autonomically blockaded conditions, and it prevented the post-AF increase in the RA end-systolic dimension and the decrease in the percentage of RA systolic shortening with autonomic blockade. AS was beneficial whether or not baseline inotropy was enhanced by AS. The duration of AF following atrial stimulation was the same before and after AS, but when compared to controls, AS treatment appeared to prolong AF. CONCLUSIONS: Cardiac glycosides exert a favorable effect on AF-induced RA stunning, but this action is unrelated to its effects on the duration of AF.

Animals↗