Search PubMed⌕ Search

Biomedical subjects

M Hassan

Publications and source records attributed to M Hassan.

At least 91 records · Page 5Linked to original sources

Human growth hormone treatment of short-stature children born small for gestational age: effect on muscle and adipose tissue mass during a 3-year treatment period and after 1 year's withdrawal.

In addition to its growth promoting effect, GH has profound metabolic effects that have not always been evaluated in longitudinal studies. We have recently shown that the effect of GH on body composition can be evaluated by magnetic resonance imaging measurement of adipose and muscle tissue cross-sectional (cs) areas in the thigh. The aim of this study was to evaluate the long-term effects of human GH (hGH) (0.2 IU/kg day) on muscle and adipose tissue mass during a 3-yr treatment period and after 1 year's withdrawal in short SGA (small for gestational age) children. Measurement of muscle and fat tissue mass by magnetic resonance imaging of the thighs was used to study the metabolic effect of hGH in 14 prepubertal short children born SGA. Results were compared with those of a control group of 7 normal children followed longitudinally. An increase of muscle tissue cs area was observed during the 3 yr of hGH treatment, an increase which was significantly different during the first 2 yr of treatment from that seen in controls (+31.2+/-2.6% and +18.1+/-1.8% during the 1st and 2nd year, respectively, vs. +9.1+/-2.6% change during 1 yr in controls). After a significant decrease in adipose tissue cs area during the first year of therapy (-16.4+/-3.4% vs. baseline values), an increase in adipose tissue cs area occurred during the second and third years. At the end of the third year, the muscle tissue cs area change was significantly greater in SGA-treated children, as compared with controls (+71.6+/-4.6% vs. 22.1+/-4.6%; P < 0.001), whereas the adipose tissue cs area change was similar in the two groups (+12.6+/-9.5% vs. +19.9+/-4.2%). After hGH withdrawal, the effects were opposite after 3 months, as compared with those observed after the first 3 months of hGH administration, whereas no additional significant change was seen after 1 yr off treatment, indicating the maintenance of muscle and adipose tissue mass. In conclusion, hGH administered to SGA children is effective in improving growth velocity and has long-term effects on muscle and adipose tissue mass. These effects may lead to speculation about the sensitivity of these tissues to GH. The physiological consequences of such effects must be evaluated.

Adipose Tissue↗

Impact of National Schistosomiasis Control Program in Kafr El-Sheikh governorate, Nile Delta, Egypt: an independent evaluation.

A longitudinal study has been conducted (1991-1997) to evaluate the impact of repeated selective chemotherapy on human transmission indices of Schistosoma mansoni infection. The study population included 8370 individuals inhabiting four villages and their satellites and representing high and low S. mansoni endemicity communities in Kafr EI-Sheikh governorate. A parasitological survey was conducted for three successive years (1991-1992 and 1993). Each time infected received praziquantel (PZQ) chemotherapy. In 1997, a fourth parasitological survey was done. During the period from 1994-1996 only routine diagnosis and treatment of schistosomiasis offered by the Ministry of Health and Population (MOHP) was going on. Study results revealed a decrease in S. mansoni prevalence and intensity of infection in the first three years. The drop was marked after the first year. In 1997, after the cessation of active case finding and treatment by the project team, an upward trend was observed for both prevalence and geometric mean egg count (GMEC) especially for the high prevalence villages. However, all indices were kept at significant low levels as compared to base-line values in 1991.

Adult↗

Sanitation characteristics of some food processing industries.

The present investigation was carried out to evaluate the sanitary conditions surrounding the food throughout the production stages in some food plants. Observation of the sanitary measures of the studied plants revealed that only 3 out of the 7 plants (42.9%) have acceptable sanitation that complies with the sanitary requirements specified by WHO. Personal hygiene and storage conditions were the most critical problems found in the studied plants. Laboratory examination of nasal and throat swabs and stool samples of workers was carried out to uncover the chronic carriers. Among the food handlers examined 46.3% were positive for intestinal parasites. Bacteriological examination of stool specimens revealed that 4.3% of carriers of Salmonella paratyphi and none were carriers of Vibreo species. Nasal swabs were also positive for Staph. aureus in 29.8% of all the examined swabs. Analysis of the main products of the studied plants revealed generally that the bacterial load of the products of plants having acceptable sanitary conditions was lower than that of the products of the other plants. The frozen vegetable products had a total aerobic mesophilic plate count ranging from 8.1 x 10(4) cfu/g in okra and 3.7 x 10(5) cfu/g in mixed vegetables. The total aerobic plate count of the ice cream (1 x 10(3) cfu/g) complies with specified Egyptian standards. However, the coliform count (9 x 10(1) MPN) was higher than the recommended limit. Lead and cadmium levels were also investigated in all products. The maximum detected level of lead was that of cream wafer (0.94 ppm) followed by banana wafer (0.82 ppm). The two detected levels were higher than Egyptian standards. The lead level in ice cream (0.19 ppm) was also higher than the specified standards. The relatively high levels of lead in cream wafer and ice cream may be attributed to more than one factor; the added color and the old machinery used in some production steps are the most accursed factors. On the other hand, the observed level of cadmium ranged between 0.046 ppm in raw mil and 0.3 ppm in soft cheese.

Colony Count, Microbial↗

Mutagen sensitivity as a susceptibility marker for human hepatocellular carcinoma.

Although the pathogenesis of hepatocellular carcinoma (HCC) remains poorly understood, hepatitis B virus and dietary aflatoxin exposures are established etiological factors for this disease. We conducted a pilot study of 28 patients with HCC and 110 healthy controls matched for age, sex, and ethnicity to determine whether constitutional genetic instability, based on the quantification of mutagen-induced chromatid breaks in cultured lymphocytes, modifies an individual's risk of HCC development. The mean numbers of bleomycin-induced breaks per cell for cases and controls were 0.92 and 0.55, respectively (P < 0.0001). For benzo(a)pyrene diol epoxide (BPDE) sensitivity, the values were 0.90 for cases and 0.46 for controls (P < 0.0001). Nearly 68% of the cases but only 27% of the controls exhibited bleomycin sensitivity (i.e., had > or = 0.68 breaks per cell). Eighty % of the case group but only 22% of the control group exhibited BPDE sensitivity (i.e., had > or = 0.58 breaks per cell). On multivariate analyses, both bleomycin sensitivity and BPDE sensitivity were associated with significantly elevated risks for HCC, with odds ratios (95% confidence intervals) of 5.63 (2.30, 13.81) and 14.13 (3.52, 56.68), respectively. For individuals who were sensitive to both assays, the risk was 35.88. A synergistic interaction between the bleomycin sensitivity and BPDE sensitivity in HCC risk was suggested. These preliminary findings suggest that differences in host factors related to the predisposition to chromosome breakage, the capacity for DNA repair, or both may be involved in HCC development by influencing the predisposition of hepatitis B virus integration into human DNA or that the carcinogens induced DNA damage susceptibility. A larger study is needed to confirm these intriguing results.

7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide↗

[Prenatal MRI of corpus callosum agenesis. Study of 20 cases with neuropathological correlations].

Twenty prenatal MR studies of corpus callosum agenesis were retrospectively studied and compared with neuropathologic examinations (18) or postnatal imaging (2). Corpus callosum agenesis were either complete (14) or partial (6). Positive diagnosis was made in 19 cases/20. The diagnosis of "isolated" or "associated" corpus callosum agenesis was assessed in 11 cases/15. MR depicted 15 of the 33 associated neurologic abnormalities. Prenatal MR is a valuable complementary technique for the diagnosis of corpus callosum agenesis when sonography is doubtful. MR could improve prognosis evaluation, since it enables depiction of associated abnormalities, notably gyral abnormalities, posterior fossa malformations, and intra-cranial cysts. MR images prove to be useful before neuropathologic examinations.

Agenesis of Corpus Callosum↗

Bosentan, a novel synthetic mixed-type endothelin receptor antagonist, attenuates acute gastric mucosal lesions induced by indomethacin and HCl in the rat: role of endogenous endothelin-1.

Endothelin-1 has been reported to be responsible for gastric mucosal damage in various experimental models. We evaluated the role of endogenous endothelin-1 in the pathogenesis of gastric mucosal damage induced by indomethacin and HCl in the rat. Rats were given indomethacin (25 mg/kg) subcutaneously, and 15 min later, 0.2N HCl intragastrically. Gastric mucosal damage, gastric endogenous endothelin-1, and gastric mucosal hemodynamics were measured. The effects of bosentan, a mixed endothelin receptor antagonist, on gastric mucosal integrity and hemodynamics were assessed. Gastric endogenous endothelin-1 was significantly elevated at 20 min, gastric mucosal blood flow began to decrease significantly at 25 min, and gastric damage occupied 52.2% of the total glandular mucosa at 135 min after injection of indomethacin. Intragastric pretreatment with bosentan (5, 10, 30, and 60 mg/kg) significantly attenuated gastric damage, to 26.1%, 7.7%, 3.6%, and 1.6%, respectively, of the total glandular mucosa. Bosentan (60 mg/kg) prevented the initial decrease of blood flow and, even at 135 min, improved blood flow and hemoglobin oxygen saturation significantly. We suggest that indomethacin-induced endogenous endothelin-1 diminishes gastric mucosal blood flow and tissue oxygenation and ultimately causes gastric damage. Endogenous endothelin-1 may play an important role in the pathogenesis of the acute gastric mucosal lesions induced by indomethacin and HCl.

Animals↗

Dynamic gadolinium-enhanced subtraction MR imaging--a simple technique for the early diagnosis of Legg-Calvé-Perthes disease: preliminary results.

PURPOSE: To determine whether the simple technique of dynamic gadolinium-enhanced subtraction MR imaging, which is available on standard MR units, can detect ischemia of the femoral head in children with early Legg-Calvé-Perthes disease (LCP). MATERIALS AND METHODS: Bone perfusion of eight hips in four patients (mean age 7.5 years) was studied using dynamic gadolinium-enhanced subtraction MR imaging at the onset of proven LCP (with initial negative plain films). Enhancement of subtracted images was compared with that on standard MR images and with bone scintigraphy findings. RESULTS: Subtraction MR imaging depicted ischemia as a widespread absence of enhancement and was in good agreement with bone scintigraphy. The subtraction technique improved the sensitivity and the specificity of MR imaging in two children. Furthermore, subtraction MR imaging allowed recognition of the pattern of early reperfusion. CONCLUSION: Our preliminary results indicate that dynamic gadolinium-enhanced subtraction MRI is a simple and promising means of early recognition of ischemia in LCP.

Child↗

Community education to encourage use of emergency obstetric services, Kebbi State, Nigeria. The Sokoto PMM Team.

PRELIMINARY STUDIES: Focus group discussions and a mini-survey in Kebbi State, Nigeria, revealed poor knowledge of obstetric complications, lack of confidence in health services, and cultural barriers to seeking care. INTERVENTIONS: After upgrading services in emergency obstetric facilities, the team began community education to encourage utilization. Messages focused on recognition and need for prompt treatment of complications, and addressed men's role as decision-makers. Beginning in 1992, messages were disseminated through weekly meetings with community opinion leaders, video shows, posters and handbills. RESULTS: A post-intervention mini-survey showed knowledge gains of over 30% among women and men. The increase was greatest (59% increase among women and 55% among men) on the need for prompt care for women with obstetric complications. However, utilization of emergency obstetric services did not increase. At Maiyama Maternity Center, referrals declined from 18 in 1992 to four in 1995. At Jega Health Center, referrals remained relatively stable at 20-30/year, but the number of women with major obstetric complications treated declined from 234 in 1992 to 136 in 1995. At Birnin Kebbi Specialist Hospital, the referral center, the number of women with complications treated declined from 200 in 1990 to 152 in 1995. COSTS: The cost of community education was approximately US $9500, of which 15% was contributed by the community. CONCLUSIONS: Increased awareness of the signs of obstetric complications and the need for prompt treatment among community women and men did not result in greater utilization of emergency obstetric services at the facilities studied.

Community Health Services↗

Ultrasonographic assessment of inflammatory bowel disease in children: comparison with ileocolonoscopy.

OBJECTIVES: To determine the feasibility and value of transabdominal ultrasonography of the terminal ileum and colon of children with inflammatory bowel disease (IBD) and to compare the findings with those of ileocolonoscopy. STUDY DESIGN: Thirty-eight patients ranging in age from 4 to 18 years who underwent ileocolonoscopy for management of IBD or for diagnosis were studied prospectively. Twenty-one patients had Crohn disease, nine had ulcerative colitis, and eight served as control subjects. Transabdominal ultrasonography was performed on the day before ileocolonoscopy. Ultrasonographic findings were compared with the results of ileocolonoscopy, used as the reference method. RESULTS: Peristalsis was recorded in all segments of the control subjects; the thickness of the terminal ileum was always less than 2.5 mm, and that of the large bowel, 2 mm or less. In the two patient subgroups, the thickness range of affected ileal and colonic segments was similar, but values were significantly different from those of the control subjects (chi-square test, p <0.0001). The overall sensitivity of the method was 88%, and the specificity, 93%. CONCLUSION: Transabdominal ultrasonography should prove to be a useful clinical and investigational technique, although further studies are needed to assess its value in the treatment of children with IBD.

Adolescent↗

Phosphoramidon, an endothelin converting enzyme inhibitor attenuates local gastric ischemia-reperfusion injury in rats.

Recently increased production of endothelin-1 has been implicated in the pathogenesis of gastric ischemia-reperfusion injury. We have investigated the effects of endothelin converting enzyme inhibition on local gastric ischemia-reperfusion injury in rats by using two metalloprotease inhibitors, phosphoramidon and thiorphan. In presence of exogenous 0.15M HCI intragastrically, local ischemia was induced by the clamping of left gastric artery for 15 min and reperfusion was done for 30 min. In separate group of rats, phosphoramidon (10-60 mg/kg) or thiorphan (60 mg/kg) were given as i.v. bolus injection immediately before the induction of ischemia. Phosphoramidon dose dependently attenuated the macroscopic and microscopic mucosal injuries while thiorphan did not. These results indicate that phosphoramidon-sensitive endothelin converting enzyme activity is highly present in stomach and phosphoramidon, by inhibiting the conversion of big endothelin-1 to endothelin-1 attenuated the gastric mucosal damage in this model.

Animals↗

Somatostatin in neuroblastoma and ganglioneuroma.

Neuroblastoma, a childhood tumour of the sympathetic nervous system, may in some cases differentiate to a benign ganglioneuroma or regress due to apoptosis. Somatostatin may inhibit neuroblastoma growth and induce apoptosis in vitro and was therefore investigated. Using a radioimmunoassay, we found that all ganglioneuromas contained high somatostatin concentrations (> 16 pmol/g), significantly higher than neuroblastomas (n = 117, median 2.8 pmol/g), healthy adrenals, Wilms' tumours, phaeochromocytomas and other neuroendocrine tumours (P < 0.001). Neuroblastomas contained more somatostatin than control tumours (P < 0.001-0.05). Neuroblastomas amplified for the MYCN oncogene contained less somatostatin than non-amplified tumours (1.2 pmol/g versus 4.0 pmol/g, respectively; P = 0.026). In a clinically unfavourable neuroblastoma subset (age > 12 months, stage 3 or 4) 16 children with high concentrations of somatostatin in primary tumours had a better prognosis than 23 with low somatostatin (46.7% versus 0% survival at 5 years, P < 0.005). Scintigraphy using 111In-pentetreotide identified tumours expressing high-affinity somatostatin receptors in vivo. However, no significant correlation was found between somatostatin receptor expression and peptide content in 15 tumours. Similarly, human SH-SY5Y neuroblastoma xenografts grown in nude rats showed low somatostatin concentrations, but were positive for somatostatin receptor scintigraphy. Treatment of these rats with the somatostatin analogue octreotide seemed to upregulate in vivo receptor expression of somatostatin and vasoactive intestinal peptide more effectively than 13-cis retinoic acid. In conclusion, somatostatin in neuroblastoma is associated with differentiation to benign ganglioneuromas in vivo and favourable outcome in advanced tumours. Furthermore, somatostatin receptor scintigraphy may identify tumours with high-affinity receptors in children that might benefit from targeted therapy using synthetic somatostatin analogues.

Animals↗

Gastric mucosal injury induced by local ischemia-reperfusion in rats. Role of endogenous endothelin-1 and free radical.

We investigated the role of an endogenous vasoconstrictor peptide endothelin-1 (ET-1) and free radicals in local gastric ischemia-reperfusion injury in rats. Local gastric ischemia was induced by clamping the left gastric artery for 15 min and reperfusion was done for 10-30 min in the presence of 150 mM exogenous HCl intragastrically. Local gastric ischemia and reperfusion resulted in significant macroscopic and microscopic gastric mucosal damage together with elevation of gastric tissue ET-1 concentration. Gastric tissue ET-1 was found to increase after 15 min of ischemia alone and also with 30 min of reperfusion. A novel nonpeptide endothelin receptor antagonist, bosentan, or a combination of radical scavengers (superoxide dismutase, catalase, and deferoxamine) both attenuated gastric mucosal injury. However, the greater protection observed with bosentan than with radical scavengers might reflect a preferential role of endothelin-1 in this type of injury.

Animals↗

Noninvasive assessment of gastric acid secretion in man. Application of electrical impedance tomography (EIT).

Electrical impedance tomography (EIT) is a tubeless technique that generates tomographic images of gastric resistivity. We investigated the application of EIT to measure gastric acid secretion. Nineteen normal subjects underwent a standard intubation test. Basal acid output (BAO) and stimulated acid output (SAO) (millimoles per hour) were measured before and after pentagastrin, respectively. On a different day, EIT was performed before (basal) and after pentagastrin (stimulated). The changes in impedance over time were measured and the area under the curve (AUC) was calculated. Both the tests were repeated in 13 subjects after omeprazole treatment. As in the intubation test, there was the expected increase in AUC value after pentagastrin (basal vs stimulated; 1.2 +/- 2.8 vs 731 +/- 297, P < 0.0001). A significant fall in acid output and AUC following omeprazole pretreatment was observed (without vs with omeprazole; 20.5 +/- 5.7 vs 0.03 +/- 0.06, P < 0.0001 for intubation test and 731 +/- 297 vs 44 +/- 172, P < 0.0001 for EIT). There was a significant correlation between SAO and the delta AUC with (r = 0.65 P < 0.001) or without (r = 0.95, P < 0.001) omeprazole and in all the experiments (r = 0.87, P < 0.001). This study demonstrates the predictable change of gastric impedance and may be useful as a noninvasive test for measuring gastric acid secretion.

Adolescent↗

High busulfan concentrations are associated with increased transplant-related mortality in allogeneic bone marrow transplant patients.

The aim of this study was to investigate the importance of busulfan concentrations for short- and long-term survival in autologous (ABMT) and allogeneic (BMT) bone marrow transplant recipients. One hundred and seventy-three patients were included in the study; 87 ABMT and 85 BMT patients. All patients received busulfan 1 mg/kg four times daily for 4 days followed by cyclophosphamide 60 mg/kg/day for 2 days. Busulfan concentrations were measured and the mean concentration calculated for each patient. There was no difference in busulfan concentrations between BMT and ABMT patients. Patients who died before day 100 had significantly higher busulfan concentrations than patients surviving beyond day 100 (719 ng/ml vs 589 ng/ml; P < 0.02). BMT patients who had busulfan concentrations in the highest quartile had significantly worse disease-free survival (DFS) and survival compared to other patients. The transplant-related mortalities (TRM) at 100 days were 29 and 14% in patients in the highest quartile and remaining patients, respectively. There was no difference in relapse incidence. High busulfan concentrations were associated with increased TRM but no difference in either survival or DFS could be found for the ABMT patients. Monitoring of busulfan concentrations is important in reducing the risk for TRM in patients undergoing bone marrow transplantation.

Adolescent↗

Skill-specific staffing intensity and the cost of hospital care.

Hospital managers have changed their staffing strategies to reduce the cost of care. Such hospitals may be both understaffed and underskilled in terms of some caregivers. Understaffing and underskilling may have indirect effects that offset the benefits of payroll cost reductions. This article indicates that in 1991 some California hospitals were understaffed in terms of specific bedside caregivers and had higher costs than did hospitals employing more of those caregivers.

California↗