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Biomedical subjects

H Hussein

Publications and source records attributed to H Hussein.

18 recordsLinked to original sources

Seasonal variation of the ovarian follicular dynamics and luteal functions of sheep in the subtropics.

This study was undertaken to describe the development of individual follicles and corpora lutea (CL) in Ossimi ewe lambs at different seasons of the year in the subtropics. Seven ewe lambs underwent daily ultrasonographic examination for 20 interovulatory periods (IOP) during spring, winter and autumn. Ovarian follicles >or=2 mm and corpora lutea were counted and measured. Blood samples were taken for progesterone (P(4)) analysis. All ewe lambs included, but one, were cyclic in all seasons studied. Three (65%) and two (35%) follicular waves were detected per estrous cycle. None of the characteristics of the large follicles was affected by season. Follicles >or=2 mm in diameter were significantly higher in winter. The CL developed slowly in autumn. Serum P(4) level was higher in autumn. Double ovulation was observed only in autumn. The data demonstrated that Ossimi sheep in the subtropics were cyclic in most seasons of the year. Season affected mainly the luteal functions with little influences on the follicular characteristics.

Animals↗

Association of damage with autoantibody profile, age, race, sex and disease duration in systemic lupus erythematosus.

OBJECTIVE: To determine if there is any association between autoantibody profile and damage in a cohort of patients with systemic lupus erythematosus (SLE). METHODS: A prospective cohort of SLE patients attending two SLE clinics in Birmingham was analysed. All patients fulfilled ARA criteria for SLE. Detailed clinical and serological information was recorded at each visit. Damage according to the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SLICC/ACR DI) was recorded 6-monthly and the last score in the year 2000 or prior to death was used in the analysis. Univariate analysis was performed with the chi(2) test, Fisher's exact test or univariate analysis of variance. Multivariate analysis was done with binary logistic regression. RESULTS: A total of 348 patients (326 females) were studied, comprising 208 Caucasians, 65 Afro-Caribbeans, 59 Asians, four Orientals and 12 others. There were 32 (9.2%) deaths and 156 (44.8%) patients had damage recorded during follow-up. The presence of damage showed no significant association with race, sex or anti-cardiolipin, anti-Ro, anti-La, anti-Sm, anti-RNP and anti-dsDNA antibodies. Only age, disease duration and other antibodies to extractable nuclear antigens (ENA) were found to be associated with the presence of damage. When individual organ damage was analysed, the only significant associations were of anti-Ro with ocular damage and of other anti-ENA antibodies (anti-Scl-70 and/or anti-Jo-1) with premature gonadal failure. Other autoantibodies were not predictive of damage in individual organs. CONCLUSIONS: Although autoantibodies are useful in diagnosis and predicting disease activity in SLE, they do not appear to be useful in predicting damage in SLE.

Adolescent↗

Transplacental chemical exposure and risk of infant leukemia with MLL gene fusion.

Infant acute leukemia (IAL) frequently involves breakage and recombination of the MLL gene with one of several potential partner genes. These gene fusions arise in utero and are similar to those found in leukemias secondary to chemotherapy with inhibitors of topoisomerase II (topo-II). This has led to the hypothesis that in utero exposures to chemicals may cause IAL via an effect on topo-II. We report a pilot case-control study of IAL across different countries and ethnic groups. Cases (n = 136) were population-based in most centers. Controls (n = 266) were selected from inpatients and outpatients at hospitals serving the same populations. MLL rearrangement status was derived by Southern blot analysis, and maternal exposure data were obtained by interviews using a structured questionnaire. Apart from the use of cigarettes and alcohol, very few mothers reported exposure to known topo-II inhibitors. Significant case-control differences were apparent for ingestion of several groups of drugs, including herbal medicines and drugs classified as "DNA-damaging," and for exposure to pesticides with the last two being largely attributable, respectively, to one nonsteroidal anti-inflammatory drug, dipyrone, and mosquitocidals (including Baygon). Elevated odds ratios were observed for MLL+ve (but not MLL-ve) leukemias (2.31 for DNA-damaging drugs, P = 0.03; 5.84 for dipyrone, P = 0.001; and 9.68 for mosquitocidals, P = 0.003). Although it is unclear at present whether these particular exposures operate via an effect on topo-II, the data suggest that specific chemical exposures of the fetus during pregnancy may cause MLL gene fusions. Given the widespread use of dipyrone, Baygon, and other carbamate-based insecticides in certain settings, confirmation of these apparent associations is urgently required.

Acute Disease↗

Tear film MMP accumulation and corneal disease.

BACKGROUND/AIMS: Matrix metalloproteinases (MMPs) accumulate in the tears of patients with active peripheral ulcerative keratitis (PUK) but it is unknown whether these enzymes have a central role in disease progression. The aims of the present investigation were to determine the source of these enzymes and to ascertain whether their accumulation in tears is a phenomenon specific to PUK or a general feature of other anterior segment diseases. METHODS: The experimental samples were obtained from the culture media of conjunctival and corneal epithelial cells, from fractionated blood plasma and leucocytes of healthy subjects and patients with rheumatoid arthritis, and from the tears of healthy subjects and patients with a variety of anterior segment diseases. The MMPs of all samples were visualised by zymography and tear samples were assayed using nitrophenol acetate and an MMP-9 susceptible quenched fluorescent peptide as substrate. RESULTS: The major MMPs that accumulate in the tears of patients with rheumatoid arthritis with active ocular disease are MMP-9 and a species of M(r) 116,000. By comparing the zymographic activity profiles of the gelatinases present in the samples obtained, it was deduced that the main source of these MMPs was granulocytes. Their accumulation in tears was not unique to patients with PUK; detectable amounts of the enzymes also occurred in the tears of patients with keratoconus with associated atopic disease, patients undergoing treatment for herpetic eye disease, and patients with systemic and non-systemic dry eye disease. CONCLUSION: The MMPs that accumulate in tears are mainly derived from granulocytes. This may be effected by autoimmune diseases that involve ocular tissue or by ocular diseases that induce an inflammatory response.

Adolescent↗

Water-in-Hydrocarbon Emulsions Stabilized by Asphaltenes at Low Concentrations.

The role of Athabasca asphaltene particles and molecules in stabilizing emulsions was examined by measuring the surface area of water-in-toluene/hexane emulsions stabilized by various asphaltene fractions, each with a different proportion of soluble and insoluble asphaltenes. The stabilized interfacial area was found to depend only on the amount of soluble asphaltenes. Furthermore, the amount of asphaltenes on the interface was consistent with molecular monolayer coverage. Hence, at low concentrations, asphaltenes appear to both act as a molecular surfactant and stabilize emulsions. The effect of the hexane : toluene ratio on emulsion stability was examined as well. At lower hexane : toluene ratios, more asphaltenes were soluble but the surface activity of a given asphaltene molecule was reduced. The two effects oppose each other but, in general, a smaller fraction of asphaltenes appeared to stabilize emulsions at lower hexane : toluene ratios. The results imply that the emulsifying capacity of asphaltenes is reduced but not eliminated in better solvents. Copyright 2000 Academic Press.

Journal Article↗

Interaction of Ionic Species and Fine Solids with a Low Energy Hydrophobic Surface from Contact Angle Measurement.

Interactions of ionic species, (organic and inorganic) precipitates, and fine solids with a low energy hydrophobic surface were examined using a model system of paraffin wax in aqueous solutions. Contact angle measurement was used to evaluate the interactions between paraffin wax and testing variables. No changes in contact angle were observed with various types of metal and metal hydroxyl ions, metal hydroxyl precipitates, fine silica, and alumina powders, suggesting weak or absence of interactions between these species and paraffin wax. At pH <9, the presence of amine reduced the contact angle, but no pH dependence on contact angle was observed for a given amine concentration. A sharp decrease in contact angle was observed at higher pHs, where precipitates of amine molecules formed probably on wax surfaces. In the presence of lauric acid, on the other hand, contact angles reduced at a pH below 8, due to the formation of precipitates, but the reduction was less significant, compared with the reduction by amine precipitates. At high pHs, adding lauric acid did not show any effect on the measured contact angles. The significant effect of fine solids on contact angle was observed only when the solids were made hydrophobic by adsorbed surfactants. The present study further demonstrated that both the thermodynamic criteria and the interactions among substrate/solids/surfactants/metal ions must be considered in identifying the effect of different factors on the wettability of low energy hydrophobic surfaces. Copyright 1998 Academic Press.

Journal Article↗

Laparoscopic versus open appendectomy: a prospective randomized trial.

To study comparative results between laparoscopic and open appendectomy, all the patients with suspected acute appendicitis who presented between January 1992 and December 1994 (N = 210) were randomized into two groups: laparoscopic (LA, n = 106) and open appendectomy (OA, n = 104). Patient demographics, pathological findings, operative time, postoperative course, and cost were analyzed. Age, gender, previous laparotomy, intraoperative diagnosis, and perforated appendix rate were comparable between both groups. Mean operative time was longer in the LA group (p < 0.05). Earlier resumption of a regular diet, shorter postoperative stay, and less postoperative analgesia also were observed in the LA group (p < 0.05). Postoperative morbidity and hospital readmissions were similar in both groups (p > 0.05). Higher operative cost was observed in the LA group, but global cost was lower in this group (p < 0.05). Laparoscopic appendectomy shows a more comfortable postoperative course (oral resumption, postoperative stay, and analgesia) over open appendectomy, with similar postoperative morbidity. The LA group showed more operative but less global cost.

Acute Disease↗

Regression of severe atherosclerotic plaque in patients with mild elevation of LDL cholesterol.

BACKGROUND: Intensive risk factor reduction in patients with dyslipidemias and coronary atherosclerosis has been shown to result in alterations in coronary artery morphology and reduced clinical events. However, the impact of such interventions in populations with relatively normal levels of low-density lipoproteins (LDL) is unclear. METHODS: To test the hypothesis that intensive risk factor reduction results in angiographic regression in patients with only mildly elevated levels of LDL, 14 patients with angiographically proven coronary atherosclerosis were entered into the University of California Davis Coronary Artery Disease Regression Program and intensively treated with pharmacologic and nonpharmacologic interventions for 2 years. Quantitative angiography was performed prior to and after 2 years of therapy to determine changes in coronary artery diameter. RESULTS: As a result of this program, dietary fat intake was reduced by 58% and LDL fell from 120 +/- 7 mg/dL to 104 +/- 6 mg/dL (p = 0.05). The average diameter of the measured arterial locations (including all 53 stenoses and 292 nondiscrete regions) on study entry was 2.74 +/- 0.05 mm. After 24 months, there was a net increase in arterial diameter (regression) of +0.05 +/- 0.04 mm to 2.81 +/- 0.05 mm (p = 0.01). While there was no significant change in the average diameter of discrete stenoses, all 8 lesions > or = 50% initial diameter narrowing regressed, with a mean diameter change of + 0.2 mm. Conversely, only 1 of 8 mild lesions < or = 20% regressed, while 4 progressed. Intermediate lesions (20% to 50%, n = 37) had balanced progression and regression. CONCLUSIONS: When examined as a continuous variable, there was a significant linear correlation between initial lesion severity (% stenosis) and the extent of regression (mm). Therefore, risk factor reduction (dietary therapy, exercise, psycho-social counseling, and lipid lowering therapy) in patients with only mild dyslipidemia results in angiographic regression of more severe lesions (> 50% initial stenosis), but does not prevent progression of mild lesions (< 20%). These findings demonstrate that intensive risk factor reduction in patients with only mild elevation of lipids beneficially influences the morphology of the most severe lesions.

Adult↗

Socio-economic factors associated with intestinal parasites among children living in Gombak, Malaysia.

Fecal specimens collected from 456 school children in Gombak, Malaysia, revealed an overall prevalence rate of 62.9%. The most common parasite found was Trichuris trichiura (47.1%) followed by Giardia intestinalis (14.7%), Entamoeba coli (11.4%), Entamoeba histolytica (9.9%) and Ascaris lumbricoides (7.9%). Infection rates were high among the Indonesian immigrant workers' children (90%) followed by the Orang Asli (79.5%), Malay (59.4%) and Indians (36.4%). Females (66.3%) had a higher prevalence rate than the males (58.5%). The prevalence of infection was found to be associated with the socio-economic status, water supply, sanitary disposal of feces and family size. Albendazole administered as a single dose (400 mg) was found to be effective against Ascaris (100%) and hookworm (92.3%) but was not effective against Trichuris (39.2%).

Adolescent↗

Laser probe ablation of normal and atherosclerotic human aorta in vitro: a first thermographic and histologic analysis.

The metal-tipped optical fiber or "laser probe" has been extensively studied in animal preparations in vivo and in human clinical trials of revascularization. The aim of this study was to evaluate the thermal characteristics of laser probe tissue ablation and to contrast the vascular tissue response to exposure to the laser probe and bare optical fiber. A 2 mm laser probe was heated with up to 4 W of argon-ion laser irradiation and applied to six postmortem strips of human nonatherosclerotic aorta as well as to five atherosclerotic aortic specimens. Surface temperature maps of the laser probe and of the vascular tissue in air were obtained via 8 to 12 micron thermographic imaging. Laser probe temperature was additionally monitored via thermocouples. Two strips each of normal and diseased aorta were irradiated directly with the bare optical fiber. Thus a total of 43 laser probe application sites and 19 bare fiberoptic laser irradiation sites on a total of 15 aortic strips were analyzed both thermographically and histologically. Based on measured temperature rises and histologic findings, the following observations were made: (1) The laser probe heats initially at its tip and attains a uniform surface temperature distribution within 5 sec. The steady-state temperature attained by the probe is inversely related to the thermal conductivity of the surrounding media. In all media studied, probe temperature increases linearly with applied laser energy. (2) Tissue ablation starts at temperatures greater than 100 degrees C, and ablation temperatures typically exceed 180 degrees C. Adventitial temperatures during laser probe application may reach 70 degrees C. Tissue ablation is enhanced both by greater laser energy deposition in the probe and by higher force at which the probe is applied to tissue. (3) Ablation of fibrofatty atheromata is more extensive than of nonatherosclerotic aortic tissue. This may be due to the lower thermal conductivity of atheromatous tissue. (4) In contrast to direct argon-ion laser ablation of aortic tissue, laser probe-mediated ablation occurs in a controlled fashion, is not associated with extensive subintimal dissections, and allows uniform conduction of heat to tissue as reflected by essentially "isothermal" injury lines.

Aorta↗

Control of schistosomiasis in the new Rahad Irrigation Scheme of Central Sudan.

As the new Rahad Irrigation Scheme in Central Sudan began its first agricultural season in 1978, the Blue Nile Health Project was being developed to prevent schistosomiasis and other water-associated diseases in the Rahad and Gezira-Managil schemes. Taken as an indication of overall transmission in the Rahad scheme, the prevalence of infection among children in the newly established schools was found initially to be 14% for Schistosoma mansoni and 1% for Schistosoma haematobium in 1980. In the older Gezira-Managil irrigation system nearby, where transmission had not been controlled there was also little S. haematobium but the prevalence of S. mansoni in school-aged children was rising above 70%. To avoid a similar future in the Rahad scheme an integrated control strategy was implemented in 1980 using chemotherapy and snail control, supported by safe water supplies in every village. Under this strategy the prevalence of S. mansoni in the schoolchildren was reduced below 10% by 1983 at an annual cost of less than $4 per capita, about $300 per square kilometer. S. haematobium remained at 1% in the schoolchildren in 1983. The major cost was for village water supplies with about 20% of the total going for snail control and 10% or less for chemotherapy. Over a third of the cost was for equipment and supplies purchased abroad, requiring hard currency. Economically feasible prevention of transmission in the long-term will require reduction of the annual cost to about $1 per capita. Cost reductions should be made primarily in operation and maintenance of the water supply systems and in snail control.

Agriculture↗

Malaria control in the Gezira-Managil Irrigated Scheme of the Sudan.

The development of malaria control in the Gezira-Managil Irrigated Scheme of Central Sudan has gone through several phases. As a result of agricultural and irrigation practices in the Gezira, falciparum malaria transmission became perennial instead of seasonal and the mosquito vector developed resistance to several insecticides. Subsequent failure to maintain control led to serious epidemics after 1971. By 1975 malaria was again put under control through an annual round of house spraying with malathion from 1975 to 1980, and with fenitrothion since 1981. A proposal is outlined for a rational strategy for malaria control in the future.

Agriculture↗

Angioscopy in vivo.

Recent developments in optical instrumentation have made possible the direct, three-dimensional viewing of intravascular structures. Using an angioscope (the Trimedyne Optiscope, Trimedyne Inc., Santa Ana CA) and a xenon cold lamp (the Xenon Cold Light Fountain, Karl Storz Endoscopy America, Inc., Culver City, CA), the authors have visualized, without complications, the normal orifices of various arteries and their bifurcations in 12 dogs, the atherosclerotic aortas of eight post mortem humans, and the coronary arteries of six post mortem humans. Potential applications of the instruments include more accurate diagnosis of occlusive diseases of the blood vessels, evaluation of such interventional procedures as angioplasty, intraoperative assessment of anastomoses, and safer laser surgery. The angioscope also enables the physician to combine pressure recording and dye injection simultaneously with the visualization of the inner walls of the vessels.

Animals↗

The qualitative effects of laser irradiation on human arteriosclerotic disease.

To determine the effects of laser irradiation upon human coronary atherosclerotic disease, coronary plaques were extracted from fresh human cadaver hearts. Seventy-four diseased artery samples were sectioned either transversely or longitudinally and subjected to laser treatment from argon-ion and carbon dioxide sources. The laser beam affected vaporization and patency in fibrous, lipoid, and calcified plaques as observed histologically. Calcified blockage showed greater extent of charred remnants following controlled thermal injury than did fibrous or lipoid obstructions. The area and depth of penetration varied directly with intensity and duration of photoirradiation and inversely with the density of the atherosclerotic tissue. This study supports further research work on the use of lasers to effect relief of atherosclerotic obstructions.

Coronary Disease↗

Calcium cytochemistry and stereological morphometry of the intercalated ductal cells of the pancreas.

Using K-antimonate procedure, Ca2 binding sites in pancreatic small ductal cells were studied. Great precipitates were observed in the lumen of intercalated ducts, on luminal, contraluminal and lateral plasmalemma of centroacinar cells and in some of their organelles especially in mitochondrial matrix as well as on the euchromatin. Fine precipitates were present mainly on the endomembranes of perinuclear cisternae, endoplasmic reticulum, Golgi vesicles, mitochondria, secretory vesicles. Stereological studies showed in electron micrographs great differences from one cell type to another for the volume of mitochondria: 8% in acinar cell, 4.8% in centroacinar cell, 15.3% in small ductal cell and 4% in endocrine cell. The results strongly support the idea that centroacinar and intercalated ductal cells constitute the segments of pancreatic excretory cells, where the alkalinization of pancreatic juice takes place mainly by the secretion of bicarbonate and resorption of chloride ions.

Animals↗