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Biomedical subjects

H Orth

Publications and source records attributed to H Orth.

At least 19 recordsLinked to original sources
PubMed2006

Clinical rotation in pathology: description of a case based approach.

BACKGROUND: The implementation of a system based, integrated curriculum at the Faculty of Health Sciences of Stellenbosch University, Western Cape, South Africa, resulted in less contact time for the pathology disciplines during theoretical modules, while a weekly rotation in pathology was introduced during clinical training in the fourth and fifth years. OBJECTIVE: To describe a problem based approach for this rotation. METHODS: Students are presented with a clinical "paper" case daily, integrating as many of the pathology disciplines as possible to demonstrate the interdependence of the various disciplines. They receive chemical pathology tutorials, visit the various laboratories, and receive practical training in fine needle aspiration biopsy. On the final day, the case studies are assessed and discussed. RESULTS: Most students appreciated all activities. This rotation enhanced student interactivity and autonomy and guaranteed immediate feedback. On evaluation of the rotation it was found that the students enjoyed the rotation, learnt something new, and realised the value of group work. CONCLUSIONS: This innovation integrates pathology with clinical practice and illustrates the use of laboratory medicine in the management of common diseases seen in this country. Students appreciate learning practical skills and having to request special investigations under a pathologist's supervision changes their approach to pathology requests. Familiarity with the pathology environment empowers the student to use pathology with greater ease. A bank of case studies that can be expanded to include all medical disciplines will facilitate the application of a problem based approach and enhance communication between the basic science disciplines and the clinical and pathology disciplines.

Biopsy, Fine-Needle↗
PubMed2005

Isotopic scaling and the symmetry energy in spectator fragmentation.

Isotopic effects in the fragmentation of excited target residues following collisions of 12C on (112,124)Sn at incident energies of 300 and 600 MeV per nucleon were studied with the INDRA 4pi detector. The measured yield ratios for light particles and fragments with atomic number Z < or = 5 obey the exponential law of isotopic scaling. The deduced scaling parameters decrease strongly with increasing centrality to values smaller than 50% of those obtained for the peripheral event groups. Symmetry-term coefficients, deduced from these data within the statistical description of isotopic scaling, are near gamma = 25 MeV for peripheral and gamma < 15 MeV for central collisions.

Journal Article↗
PubMed2003

Infective endocarditis in the Western Cape Province of South Africa: a three-year prospective study.

BACKGROUND: The last 50 years have seen major changes in the epidemiology of infective endocarditis (IE). AIM: To evaluate local patient characteristics, risk factors, clinical sequelae, microbiology, morbidity and mortality in patients with definite IE. DESIGN: Prospective observational study. METHODS: Over a three-year period, patients referred with probable IE were prospectively enrolled. All received a standardized diagnostic evaluation. Epidemiological data were documented; underlying risk factors for IE were sought. Initial evaluation and follow-up (to 6 months) included the documentation of vascular or immunological phenomena, morbidity and mortality. RESULTS: Of 92 patients referred with probable IE, 47 had definite IE. These patients had a mean age of 37.7 years with a male predominance (1.6:1). Rheumatic heart disease was present in 36 (76.6%). Eight had prosthetic valves. Three had congenital heart disease, mitral valve prolapse or multiple central intravascular catheters, respectively. All denied the use of intravenous recreational drugs and only one tested seropositive for HIV. Renal involvement (59.6%) and clubbing (29.8%) were commonly observed. The 6-month mortality rate was 35.6%, while 44.7% needed valvular replacement. An aetiological diagnosis was made in 21, with viridans streptococci the most common isolate. DISCUSSION: Infective endocarditis in the Western Cape of South Africa is a disease of younger adults, with a male predominance. Rheumatic heart disease is the major predisposing factor. Degenerative heart disease and intravenous drug abuse are not important risk factors. Our data do not support the notion that HIV infection is an independent risk factor for IE. Local mortality rates are much higher than recent international figures, as is the proportion of 'culture-negative' IE.

Adult↗
PubMed2001

Control measures for wastewater treatment plants during storm flow.

In the context of the development of treatment plant control techniques, three measures for maintaining a high efficiency of treatment plants during rainfall events were tested. The three measures are increasing the nitrification volume by operating a facultative aeration, bypassing the primary sedimentation and adding flocculants before secondary sedimentation. Ammonia concentrations and ammonia loads were used in combination with rainfall forecasts as the criteria for putting the measures into operation. A simulation based on the Activated Sludge Model No. 1 and a pilot scale plant were used for testing the measures. The results show that all three measures may be suitable to cope with peak loads of treatment plants during rainfall events.

Air↗
PubMed1988

Ultrastructure of megakaryocytes in the human bone marrow of patients with primary (essential) thrombocythemia.

An ultrastructural study was performed on bone marrow specimens in 10 patients (5 males/5 females, median age 53 years) with primary (essential) thrombocythemia (PTH) and an excessive elevation of the platelet count (1,625 +/- 783 x 10(9)/l). In contrast to a not severely altered neutrophilic granulo- and erythrocytopoiesis, megakaryocytes showed conspicuous large to giant forms. These were characterized by a highly lobulated nucleus containing several nucleoli and an extensive intermediate zone of the cytoplasm with many Golgi fields, numerous profiles of the so-called demarcation membrane system and an abundance of alpha-granules and some dense bodies. Our results demonstrate that ultrastructure of the megakaryocytes in PTH does not reveal gross abnormalities, but features which are compatible with an enforced thrombocytogenetic activity in accordance with the excessively elevated platelet count. Similar changes have been described in animal experiments with induced thrombocytopenia and stimulation of platelet shedding. Evaluation of thrombocytogenesis suggests that it may be mediated by a process of fragmentation with partitioning of the extensive intermediate zone into numerous prospective platelet territories followed by segregation.

Bone Marrow↗
PubMed1983

[Idiopathic edema].

Explore the source record for details and available documents.

Biological Transport↗
PubMed1983

[N-acetyl-cystein-(NAC)-activated creatinkinase (CK) and isoenzyme CK-MB in the serum of children].

We have examined the variation of creatinekinase levels (NAC-activated) with age in 170 children. The subjects included 40 neonates, 18 premature neonates, 40 small babies, 32 infants and 40 schoolchildren. The enzyme activity of CK-MM was very high in the first hours after delivery and remained high for a few days. The isoenzyme MB in healthy newborns also showed a higher catalytic concentration. These values (about 2-12 U/l) reached normal levels of adults within 4 months of life (0.5-5 U/l). The same rule applied to CK-MM: enzyme activities of 160 U/l and more in the first days of life declined to 16-75 U/l during the first 4 months. No correlation between birth trauma and the increase in serum-CK was found. Because of the increased CK-MM (and CK-MB) found in normal newborns screening for Duchenne-type muscular dystrophy should be postponed for a few weeks after delivery. In view of the relatively high endogenous serum CK-MB in the neonates (release of CK-MB from the skeletal muscle) the test lacks the specificity for cardiac damage. Intramuscular injections of several drugs lead to a distinct increase in CK activity. A rise of CK-MM was seen 4-24 h after catheterization of the heart.

Acetylcysteine↗
PubMed1977

[The pathogenetic importance of the affection and of the therapy of MS-patients' teeth in comparison to those of epileptics (author's transl)].

51 MS-patients between 18 and 50 years and an equally old control group of 51 epileptics were dentally and roentgenologically investigated. Especially the fillings of amalgam were observed. This quantitative registration showed a prevailing of 18.5% among the epileptics without statistical significance. On the other hand MS patients suffered more frequently from carious teeth. Both groups are extremely unsufficiently provided with prosthesis. 85% of all MS-patients and 71.4% of all epileptics showed progressive paradontopathics. Only 4 of 40 epileptics treated with hydantoins produced a hyperplasia of their gingivas. In view of odontogenic foci the clinical and the roentgenological results could not reveal any differences between the both groups of patients. Only granulomas of the teeth were more frequent among the MS-patients. Baasch's theory of the amalgam-etiology of MS is discussed and rejected because of lack of evidence. The problem of the focus therory is generally and specially discussed, too, as a possibility causing MS. But a connection between focus and MS is not sure in spite of striking investigations. As a general result conclusions should be drawn from the bad conditions of the MS patients' teeth with regard to a better dental providing.

Adult↗