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Biomedical subjects

E Daniel

Publications and source records attributed to E Daniel.

At least 55 records · Page 3Linked to original sources
PubMed1994

Endothelin-1 inhibits inward rectifier potassium channels and activates nonspecific cation channels in cultured endothelial cells.

A predominant inward rectifier and a small outward potassium current were obtained in whole-cell patch-clamp recordings from cultured bovine pulmonary arterial endothelial cells. Application of endothelial-1 (ET-1; 10-100 nmol/l) inhibited the inward rectifier. Washout with bath solution did not recover the current decreased by ET-1. In cell-attached studies, ET-1 (1 nmol/l) inhibited single-channel activity of the inward rectifier and in some patches enhanced activity of the outward potassium current without change of conductance. A non-specific cation current which is permeable to calcium was identified in cell-attached patches in cultured human umbilical vein endothelial cells. ET-1 (1 nmol/l) increased activity of the nonspecific cation channel. ET-1 may increase calcium influx into endothelial cells and promote synthase and release of endothelium-derived factors.

Animals↗
PubMed1994

Quantitative assessment of the visibility of unmyelinated corneal nerves in leprosy.

Unmyelinated corneal nerves were counted in 383 leprosy patients whose eyes looked normal on clinical examination and in an equal number of healthy controls. Visibility of these nerves was decreased significantly (p < 0.01) in the nasal half of the cornea in both patients and controls. There was a significant (p < 0.01) inverse correlation between age and the visibility of these nerves in patients and controls. There was a significant (p < 0.05) reduction in the visibility of these nerves as the spectrum of the disease moved from the tuberculoid to the lepromatous pole. There was no significant correlation between visibility of these nerves and the smear positivity of the patient. Neither did duration of the disease nor the duration of antileprosy treatment alter the visibility of these nerves significantly. Overall, there was a reduction in the visibility of these nerves in patients who had had leprosy reactions.

Adult↗
PubMed1993

Profile of cardiac disease in an out-patient cardiac clinic.

The pattern of cardiac disease differs from one region of the world to that of another. This paper aims at providing the profile of heart disease as seen in a Children's Hospital. A total of 468 patients were seen in a follow-up conducted between August 1989 and February 29, 1992. Among these 168 (35.9%) had congenital heart disease (CHD); 278 (59.4%) had rheumatic heart disease (RHD); while 14 (3%) had acquired heart disease of non-rheumatic origin. In patients having RHD, the mitral valve was commonly affected. Ventricular septal defect was the commonest CHD seen followed by patent ductus arteriosus. The results show that RHD is the commonest heart disease seen in a Children's Hospital in Addis Ababa. It is recommended that the issues of school surveillance, better organized secondary prophylaxis need to be addressed.

Adolescent↗
PubMed1992

A one-year study of streptococcal infections and their complications among Ethiopian children.

Post-streptococcal complications are known to be common among Ethiopian children. Little is known, however, about the epidemiology of beta-haemolytic streptococci in Ethiopia. A total of 816 children were studied during a one-year period: 24 cases of acute rheumatic fever (ARF), 44 chronic rheumatic heart disease (CRHD), 44 acute post streptococcal glomerulonephritis (APSGN), 143 tonsillitis, 55 impetigo, and 506 were apparently healthy children. Both ARF and APSGN occurred throughout the year with two peaks during the rainy and cold seasons. The female:male ratio among ARF patients was 1.4:1 and 1:1.9 among APSGN. The monthly carrier rate of beta-haemolytic streptococci group A varied from 7.5-39%, average being 17%. T type 2 was the most frequent serotype. Marked seasonal fluctuations were noted in the distribution of serogroups among apparently healthy children. Beta-haemolytic streptococci group A dominated during the hot and humid months of February-May. Strains were susceptible to commonly used antibiotics, except for tetracycline.

Carrier State↗
PubMed1992

Relapsing fever in children--demographic, social and clinical features.

Louse-borne relapsing fever (LBRF) is an acute febrile illness endemic Ethiopia. To date reports of childhood LBRF are few. The demographic, social and clinical features of eighty children with LBRF admitted to Ethio-Swedish Children's Hospital, Addis Abeba between 1989 and 1991 is presented. The mean age of patients was 8.8 years (range 4 months to 15 years). The male to female ratio was 1.2:1. Seventy-seven (97%) patients came from Addis Abeba. They came from poor families living in overcrowded homes. Fever, headache, right upper quadrant pain, chills and rigors were common symptoms. Fever and hepatosplenomegaly were common signs. Three drug regimens were used in the treatment of patients. A combination of penicillin and tetracycline, chloramphenicol alone and erythromycin alone, all given for 3 days. There was only one death. The literature on LBRF in adults is reviewed and the results are compared (1).

Adolescent↗
PubMed1991

Molecular symmetry and arrangement of subunits in extracellular hemoglobin from the nematode Ascaris suum.

The arrangement of subunits and molecular symmetry of extracellular hemoglobin from the nematode Ascaris suum, an 11.7S molecular of molecular mass 332 kDa and composed of eight identical subunits, was studied. Dissociation of the molecule at alkaline and acid pH yielded 4.6S and 2.7S components, identified as polypeptide-chain dimers and monomers, respectively. Cross-linking with glutardialdehyde followed by SDS/PAGE resulted in a maximum number of eight bands identified in order of decreasing mobility as monomeric and 2-8 cross-linked-polypeptide-chain species. Comparison with values predicted from theory shows that the distribution of protein among the various cross-linked species, obtained after different extents of exposure to cross-linker, is consistent with a two-layered arrangement of subunits involving one type of interaction between subunits from different layers and another between subunits within the same layer. Electron micrographs of the molecule showed two profiles, a square and a rectangle. We propose a model for the molecule which is eight subunits arranged in two layers, stacked in an eclipsed orientation. The proposed model is consistent with the results from sedimentation, cross-linking and electron microscopy. Taken together, our findings indicate D4 symmetry for Ascaris hemoglobin.

Animals↗
PubMed1991

Small-angle X-ray study on the quaternary structure of erythrocruorin from Caenestheria inopinata.

The erythrocruorin of the clam shrimp Caenestheria inopinata was studied in sodium phosphate buffer at pH 6.8 by small-angle X-ray scattering. The following molecular parameters were determined: radius of gyration 4.77 +/- 0.05 nm, maximum dimension 14.0 +/- 0.5 nm and a volume of 640 +/- 40 nm3. A model which fits the experimental data well is presented. The model is composed of 10 subunits arranged symmetrically in two layers, whereby five subunits are always forming a ring.

Animals↗
PubMed1991

Structure of the polypeptide chain of extracellular hemoglobin from the nematode Ascaris suum.

1. Ascaris suum extracellular hemoglobin is composed of eight identical single polypeptide chain subunits carrying two heme binding sites each. 2. Limited trypsinolysis followed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis gave a major band corresponding to half the molecular mass of an intact subunit. 3. Peptide mapping of tryptic hydrolysates yielded 27 to 30 fluorescamine positive spots, about half the number of lysyl and arginyl residues in a polypeptide chain. 4. The findings indicate that a subunit of Ascaris hemoglobin consists of two structural units of roughly equal size, corresponding to two recurring sequences, connected together by the continuity of the polypeptide chain.

Animals↗
PubMed1991

Childhood appendicitis: factors associated with its incidence and perforation in Ethiopian children.

Acute appendicitis is a common paediatric emergency necessitating surgical intervention. Factors contributing to the incidence of the disease and appendiceal perforation in all children with acute appendicitis admitted to the Ethio-Swedish Children's Hospital in Addis Abeba, Ethiopia from Jan 1983 to December 1987 were studied. There were a total of 278 cases of appendicitis, with matched controls, seen. The incidence of perforation was 67%. Statistically significant differences between cases and controls were seen for the educational status of the parents (p less than .001), the parental income (p less than .001) and the nutritional status of the patient (p less than .001). The risk of perforation increased with increased duration of the illness. Perforation was common in children with normal height and better parental education. The incidence of appendicitis appears to be related to improved socioeconomic status. Prospective studies to examine this and other associations are warranted.

Acute Disease↗
PubMed1991

Klippel-Feil syndrome in two Ethiopian children.

Klippel-Feil syndrome or congenital short neck is a rare malformation in which there is congenital fusion of two or more vertebrae in the cervical region. In some patients it is associated with other congenital malformations in the skeleton, lung and heart. Two cases of Klippel-Feil syndrome in children who also had cardiovascular malformations are described and the literature is reviewed.

Abnormalities, Multiple↗
PubMed1990

Molecular symmetry and arrangement of subunits in extracellular hemoglobin from Caenestheria inopinata.

The subunit structure of extracellular hemoglobin from the clam shrimp Caenestheria inopinata was studied using the method of cross-linking by bifunctional reagents followed by SDS/PAGE. Two phases were distinguished in the cross-linking by glutardialdehyde: a fast phase characterized by the appearance of two bands in electrophoresis corresponding to single polypeptide chains and cross-linked chain pairs, and a slow phase where five bands corresponding to even numbers, 2-10, of cross-linked polypeptide chains are observed. Theoretical curves for the distribution of protein among the various cross-linked species were calculated assuming allowed arrangements of ten identical subunits. Equally good descriptions of the cross-linking were provided by two models with dihedral symmetry: a ring arrangement with two types of alternating interactions and a two-layered eclipsed arrangement with one type of interaction between subunits from different layers and another between subunits within the same layer. A way out of the ambiguity was found by carrying out the fast phase of the cross-linking reaction with dimethyl-3,3'-dithiobispropionimidate.2HCl, a bifunctional reagent containing an S-S bond that can be cleaved by 2-mercaptoethanol, following up with glutardialdehyde in the slow phase. The observation in the presence of 2-mercaptoethanol of electrophoretic bands corresponding to trimeric and higher cross-linked polypeptide chain species rules out the alternating ring and confirms the two-layered eclipsed model. The arrangement of subunits found in this work from consecutive cross-linking can account satisfactorily for molecular profiles previously obtained from electron microscopy of Caenestheria hemoglobin.

Animals↗
PubMed1990

Survey of burn admissions to the Ethio-Swedish Children's Hospital.

A retrospective analysis of burn accidents seen in Ethio-Swedish Children's Hospital, Addis Ababa, Ethiopia over 10 years from January 1978 to December 1987 is presented. A total of 347 cases were seen, accounting for 1.73% of all hospital admissions during the period studied. One hundred eighty-six (53.9%) were males. Scald was the commonest cause, 212 patients (61.1%). Second degree burns involving the extremities were the most frequent. Forty (11.5%) of the patients died. Increased mortality was seen in males with deep third degree burns, shock, a low total protein (less than 6 g%), extensive burns, and burns involving sites other than the extremities. Preventive measures such as educational programmes in schools and on the mass media, together with implementation of legislation to minimize the hazard, are recommended.

Adolescent↗