Biomedical subjects

H Topp

Publications and source records attributed to H Topp.

At least 19 recordsLinked to original sources

PubMed2004

[Inter-rater reliability of the Barthel Index, the Activity Index, and the Nottingham Extended Activities of Daily Living: The use of ADL instruments in stroke rehabilitation by medical and non medical personnel].

This investigation addressed the question whether non-medical personnel could produce similar ratings to physicians when applying ADL scales. A sports scientist was trained in the assessment of stroke patients with the Barthel Index, the Activity Index and the Nottingham Extended Activities of Daily Living Scale. He and a rehabilitation physician assessed 20 stroke patients in first in-patient rehabilitation with these instruments. Measurements of inter-rater reliability were calculated for scores, subscales and single items, and for the latter also rater correspondence. Inter-rater reliability was good to excellent for all scores and subscales (ICC: 0.82-0.99). Reliability and correspondence was good to excellent for the items of the Barthel Scale, satisfactory to excellent for those of the Activity Index. Some 25 % of the items of the Nottingham Extended Activities of Daily Living revealed unsatisfactory reliability but still high inter-rater correspondence. Results indicate that physicians and non-medical personnel are able to apply these scales reliably to stroke patients.

Activities of Daily Living↗

PubMed2003

Process water treatment at the Ranger uranium mine, Northern Australia.

The conceptual development and piloting of an innovative water treatment system for process water produced by a uranium mine mill is described. The process incorporates lime/CO2 softening (Stage 1), reverse osmosis (Stage 2) and biopolishing (Stage 3) to produce water of quality suitable for release to the receiving environment. Comprehensive performance data are presented for each stage. The unique features of the proposed process are: recycling of the lime/CO2 softening sludge to the uranium mill as a neutralant, the use of power station off-gas for carbonation, the use of residual ammonia as the pH buffer in carbonation; and the recovery and recycling of ammonia from the RO reject stream.

Australia↗

PubMed2000

A high-performance liquid chromatographic method for the determination of 8-oxo-7,8-dihydro-2'-deoxyguanosine in urine from man and rat.

The renally excreted amount of 8-oxo-7,8-dihydro-2'-deoxyguanosine (oxo(8)dG) is a potential marker of oxidative DNA damage by reactive oxygen species. We have developed a high-performance liquid chromatographic (HPLC) method to determine oxo(8)dG in urine from humans and Wistar rats. First, 300 microl of filtered urine is prefractionated by solid phase extraction (BAKERBOND SPE C(18) Polar Plus column). Then, the HPLC separation of the fraction containing oxo(8)dG is performed using four HPLC columns (two cation exchange and two C(18) columns) in series with an automated column switching technique. Quantification of oxo(8)dG is performed by electrochemical detection (Coulochem II, ESA Inc.). Limit of detection was 0.4 nM oxo(8)dG. Recovery of oxo(8)dG added respectively in 11 or 8 concentration steps (range, 4-74 or 2-23 nM) to a pooled human or rat urine was 104.1 +/- 4.3 or 104.5 +/- 7.7%. Precision of sixfold analysis of a pooled human or rat urine carried out respectively on the same day was 2.2 or 2.4% relative standard deviation. Normal excretion rates of oxo(8)dG in healthy adult humans (five females, six males; body weight, 70.7 +/- 11 kg) and male Wistar rats (body weight, 309 +/- 13 g) were 281.7 +/- 179.1 and 333.2 +/- 47.4 pmol oxo(8)dG/day/kg weight, respectively.

8-Hydroxy-2'-Deoxyguanosine↗

PubMed2000

Renal excretion of 8-oxo-7,8-dihydro-2'-deoxyguanosine in Wistar rats with increased O(2) consumption due to cold stress.

DNA damage by reactive oxygen species is of special interest in the development of cancer and in aging. The renally excreted amount of 8-oxo-7,8-dihydro-2'-deoxyguanosine (oxo(8)dG) is a potential noninvasive marker of oxidative DNA damage. The respiratory chain of mitochondria is one source for the formation of reactive oxygen species. In the present study we investigated in Wistar rats (n = 7; mean body weight at start, 307.4 +/- 11 g) the effect of an increased O(2) consumption, i.e., energy expenditure, due to cold stress on the renally excreted amount of oxo(8)dG. First, the rats were housed for 4 days at 23.5 degrees C (basic period, BP), and then for 6 days at 10 degrees C (cold stress period, CSP), and finally for 3 days at 23.5 degrees C (recovery period, RP). The O(2) consumption (L O(2)/day/kg weight) was significantly (P < 0.0001) on average 50% higher in CSP (69.0 +/- 3.9) than in BP (45.8 +/- 4.8), and similar in BP and RP (44.3 +/- 5.4). The average renal excretion of oxo(8)dG (pmol/day/kg weight) was significantly (P < 0.025) on average 13% higher in CSP (375.5 +/- 27.7) than in BP (333.2 +/- 47. 4) and similar in BP and RP (331.8 +/- 34.3). Maximum increase in oxo(8)dG excretion of on average 17% was on the third to fifth day of the CSP. This study reveals that an increase in O(2) consumption of 50% resulted in a much lower increase in the renal excretion of oxo(8)dG.

8-Hydroxy-2'-Deoxyguanosine↗

PubMed2000

Whole-body degradation rates of transfer-, ribosomal-, and messenger ribonucleic acids and resting metabolic rate in 3- to 18-year-old humans.

Whole-body degradation rates of transfer, ribosomal, and messenger RNA were determined noninvasively in 3-, 6-, 10-, 14-, and 18-y-old female and male subjects (n = 14 per age group per sex) under normal living conditions. The method for determining the RNA degradation rates is based on measuring the renal excretion rates of special RNA catabolites (modified ribonucleosides and nucleobases) by HPLC. Resting metabolic rates were calculated for the same subjects by their body weights using formulas taken from literature. We found high correlations between the degradation rates of the different RNA classes (micromoles per day per kilogram body weight) and the resting metabolic rate (kilojoules per day per kilogram body weight): in females (n = 70), r = 0.75-0.82 and in males (n = 70), r = 0.68-0.79 (p<0.0001). We conclude that a causal relationship exists between the whole-body degradation rates of the different RNA classes and the resting metabolic rate. Therefore, in healthy subjects noninvasive determinations of RNA degradation rates could be very useful to assess the resting metabolic rate.

Adolescent↗

PubMed1998

Renal excretion of gamma-carboxyglutamic acid and metabolic rate in 3-18 years old humans.

The modified amino acid gamma-carboxyglutamic acid (Gla) occurs in several proteins such as prothrombin, blood coagulation factors VII, IX and X, proteins C, S and Z as well as matrix Gla protein and osteocalcin. The amount of Gla excreted in urine is a common indicator of the whole-body degradation of these proteins. We have determined the renal excretion rates of Gla in 3, 6, 10, 14 and 18 years old male and female human subjects (n = 14 per age group and sex) and calculated the respective resting metabolic rates (RMR) on the basis of the body weights using published formulas. We found high correlations between the excretion rates of Gla (mumol/d/kg body weight) and the RMR (kJ/d/kg body weight) in the females (n = 70) of r = 0.70 (y = 0.003x + 0.29) and in the males (n = 70) of r = 0.70 (y = 0.0038x + 0.27) and in all subjects (n = 140) of r = 0.69 (y = 0.0035x + 0.27); p < 0.01. We postulate that in children and adolescents a causal relationship exists between the whole-body degradation rate of Gla containing proteins and the metabolic rate.

1-Carboxyglutamic Acid↗

PubMed1998

Expiration of ethane in rats under variously elevated inspiratory O2-concentrations.

Expired ethane is regarded as a noninvasive indicator of lipid peroxidation. As a model of oxidative stress we have investigated in male Wistar rats (body wt. 309 +/- 15 g) the effects of various levels of elevated inspiratory oxygen concentrations on the expiration rate of ethane. After 4 days under 21 vol% O2 (basic condition) the rats were exposed for 6 or 5 days to 40, 60 or 80 vol% O2 over 8 or 23 h/day. The variously O2-enriched air was conducted through the cages and expired ethane adsorbed onto charcoal was thermo-desorbed and measured by gas chromatography. Basic ethane expiration was 3.1 +/- 0.8 pmol/100 g body wt. per min. At 40 vol% O2 over 8 or 23 h/day no increase or a maximum average 47% increase (P < 0.01) in ethane expiration occurred on day 4; 60 vol% O2 over 8 or 23 h/day led to a corresponding increase of 56 or 87% (P < 0.05 or P < 0.01) on day 3; 80 vol% O2 over 8 or 23 h/day led to a corresponding increase of 81 or 66% (P < 0.01) on days 3 or 2. Our results indicate that with up to 60 vol% O2 a temporary increase in lipid peroxidation occurs in a dose dependent manner. However, at 80 vol% O2 no further increase in the maximum ethane expiration occurred. The latter finding and the finding of only transient increase in ethane expiration in probably due to antioxidative counteraction.

Animals↗

PubMed1998

Induction of single-strand breaks in lymphocyte DNA of rats exposed to hyperoxia.

A modified technique of alkaline filter elution was used to evaluate single-strand breaks (SSB) as a measure of DNA lesions in lymphocytes of male Wistar rats exposed to 60 or 80 vol% oxygen, over 23 h/day and for 6 or 5 days, respectively. An acceleration of elution was observed with samples from experiments at both increased levels of oxygen. With proteinase K treatment, a twofold increase in elution rates after exposure to 60 vol% oxygen and a threefold increase at 80 vol% oxygen were indicative of increased occurrence of SSB. This is explained by an involvement of reactive oxygen species in DNA damage under elevated oxygen levels.

Animals↗

PubMed1998

The degradation rates of cytoplasmic tRNA, rRNA and mRNA in rats are elevated after infection with Nippostrongylus brasiliensis.

The effects of a parasitic infection with the nematode Nippostrongylus brasiliensis on the degradation rates of cytoplasmic tRNA, rRNA and mRNA in rats have been investigated by measuring the renal excretion rates of the modified RNA catabolites N6-threoninocarbonyladenosine, pseudouridine and 7-methylguanine. Between days 9 and 13 post-infection when the expulsion of N. brasiliensis is usually the most pronounced, the degradation rates of the different RNA classes were significantly higher than in the control rats (P < 0.05) by, on average, +24% (tRNA), +34% (rRNA) and +26% (mRNA). We suspect that the elevated degradation rates of RNA are related to an increased production of reactive oxygen species by the host during the expulsion of N. brasiliensis.

Animals↗

PubMed1997

Determination of degradation rates of transfer and ribosomal ribonucleic acids in cultured rat hepatocytes by measuring N6-threoninocarbonyladenosine, dihydrouridine, and pseudouridine in medium using high-performance liquid chromatography.

Modified ribonucleic acid catabolites excreted into the medium by primary cultures of rat hepatocytes (2.3 +/- 0.42 x 10(6) cells/dish) during a 24-h cultivation period were quantified by reversed-phase high-performance liquid chromatography (fmol/10(3) cells): 613 +/- 81 dihydrouridine, 46 +/- 6 N6-threoninocarbonyladenosine, 1879 +/- 220 pseudouridine. On the basis of these excretion rates and the average frequency of occurrence of these modified ribonucleosides per cytoplasmic transfer ribonucleic acid (residues: 2.6 dihydrouridine, 0.22 N6-threoninocarbonyladenosine, 3 pseudouridine) as well as per cytoplasmic ribosomal ribonucleic acid (residues: 95 pseudouridine), the degradation rates of transfer and ribosomal ribonucleic acids were calculated. The degradation rate of transfer ribonucleic acid (fmol/10(3) cells/24 h) was 236 +/- 31 (via dihydrouridine) and 211 +/- 28 (via N6-threoninocarbonyladenosine) and that of ribosomal ribonucleic acid (fmol/10(3) cells/24 h) was 13.1 +/- 1.7 (via pseudouridine and N6-threoninocarbonyladenosine).

Adenosine↗

PubMed1997

Decision-making in end-stage coronary artery disease: revascularization or heart transplantation?

BACKGROUND: Left ventricular function is the most important predictor of survival in patients with coronary artery disease. It is also an important indicator for hospital and late mortality after operation for endstage coronary artery disease. METHODS: Between April 1986 and December 1994, 514 patients with end-stage coronary artery disease and left ventricular ejection fraction between 0.10 and 0.30 underwent coronary artery bypass grafting at the German Heart Institute Berlin. Two hundred twenty-five of these patients had been referred as possible candidates for heart transplantation. The prime criterion for bypass grafting was ischemia diagnosed by myocardial scintigraphy and echocardiography ("hibernating myocardium"). RESULTS: Operative mortality for the group was 7.1%. The actuarial survival rate was 90.8% after 2 years, 87.6% after 4, and 78.9% after 6. Left heart catheterizations performed 1 year after the operation showed that left ventricular ejection fraction had increased from a mean of 0.24 +/- 0.03 preoperatively to 0.39 +/- 0.06 postoperatively (p < 0.0001). Preoperatively 91.6% of the patients were in New York Heart Association (NYHA) class III or IV; 6 months postoperatively 90.2% of the surviving patients were in NYHA class I or II. Two hundred thirty-one patients with end-stage coronary artery disease and predominant heart failure underwent heart transplantation. Their actuarial survival rate was 74.9% after 2 years, 73.2% after 4, and 68.9% after 6. All of the patients could be recategorized into NYHA class I or II after the operation. CONCLUSIONS: We conclude that coronary artery bypass grafting and heart transplantation can be used successfully to improve the life expectancy of patients with end-stage coronary artery disease. Coronary artery bypass grafting leads to an excellent prognosis for these high-risk patients when the myocardium is preoperatively identified as being viable.

Actuarial Analysis↗

PubMed1995

Assessment of lipid peroxidation in rats of different body weight by determining expired ethane.

Expired ethane is regarded as an indicator of reactive oxygen species induced lipid peroxidation. We investigated whether Wistar rats of different body weights (BW: 78 +/- 6, 121 +/- 12 and 347 +/- 30 g) and hence different metabolic rates per unit weight, expire different amounts of ethane. We found that expired ethane (pmol/100 g BW/min) decreases with increasing BW (8.6 +/- 1.8, 6.3 +/- 1.5 and 2.8 +/- 0.6, respectively). These values aas well as a recently published average value of 1.0 pmol ethane/100 g BW/min for healthy humans (average BW: 78 kg) indicate a positive relationship between lipid peroxidation and metabolic rate.

Animals↗

PubMed1994

Thallium and indium antimyosin dual-isotope single-photon emission tomography in acute myocardial infarction to identify patients at further ischaemic risk.

Dual-isotope single-photon emission tomography (SPET) with indium-111 antimyosin and thallium-201 chloride was performed in 54 patients with acute myocardial infarction (AMI) to detect the location and extent of myocardial necrosis (antimyosin) and viable myocardium (201Tl). All patients underwent intravenous thrombolytic therapy with either streptokinase (1.5 million units/90 min) or tissue plasminogen activator (80 mg/90 min). Sensitivity in detecting MI was 91% (49/54 patients). With regard to dual-isotope SPET patterns, patients were divided into three groups: match, i.e. antimyosin uptake in segments with thallium defect (n = 8); mismatch, i.e. no uptake of either of the nuclides in corresponding segments (presence of perfusion abnormalities in the absence of antimyosin uptake) (n = 5); and overlap, i.e. thallium uptake in segments with uptake of antimyosin (n = 41). Coronary angiography and thallium exercise tests were performed in 40 and 45 patients, respectively, 5-14 days after MI. Exercise-induced ischaemia occurred in 66% of patients with overlap, 14% with match and 0% with mismatch (P < 0.05 for overlap vs other groups). If, however, major in-hospital complications (sudden cardiac death, severe arrhythmias; five overlap, three overlap in addition to match/mismatch, two match, two mismatch) were included in the statistical analysis, there was no significant difference between the three groups (P = NS). Thus, although the dual-isotope pattern "overlap" identifies a subgroup of patients with a substantial amount of residual viable tissue after MI and a high probability of exercise-induced ischaemia, this criterion is of limited value in assessing short-term prognosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1994

Coronary artery bypass grafting and heart transplantation in end-stage coronary artery disease: a comparison of hemodynamic improvement and ventricular function.

Heart transplantation has now become an accepted treatment for end-stage coronary heart disease (CAD). However, the limited supply of suitable donor organs imposes constraints upon the decision of whether patients are selected for transplantation or for coronary artery bypass grafting (CABG). From April 1986 until the end of March 1992, 265 patients with end-stage CAD involving left ventricular ejection fraction (LVEF) 10% to 30% and predominant angina pectoris underwent CABG. All patients received an average of 2.9 +/- 0.3 venous grafts. Intraaortic balloon pumps were implanted in 30 patients (11.3%) who began to develop low cardiac output syndrome intraoperatively. The actuarial survival rate was 87.8% after 2 years and 86.9% after 3 years. LVEF was measured in 35 patients via left heart catheterization 12 months after their operations and was found to have increased from a mean of 23.8% to 38.1%. Left ventricular end-diastolic pressure had decreased from 16.2 mmHg to an average of 12.1 mmHg. Swan-Ganz catheterization was performed on 120 patients 6 months postoperatively. The pulmonary wedge pressure had reduced significantly from 18.1 mmHg to a mean of 12.7 mmHg (p < 0.01). From 1990 until the end of March 1992, 55 patients with CAD and predominant heart failure received transplants. Their 2-year survival rate was 66.3%. Mean LVEF was 55.6% postoperatively. We conclude that CABG is adequate for patients who have end-stage CAD and angina pectoris symptoms, and that it significantly improves hemodynamic functions. Patients suffering predominantly from heart failure (NYHA Class IV) can be transplanted and subsequently regain normal heart function.

Actuarial Analysis↗

PubMed1993

5,6-Dihydrouridine: a marker ribonucleoside for determining whole body degradation rates of transfer RNA in man and rats.

It has previously been demonstrated that N6-threoninocarbonyladenosine is virtually quantitatively excreted in urine. From the similarity of the average molar ratio of 5,6-dihydrouridine to N6-threoninocarbonyladenosine in the urine of human adults (12.6), newborns (12.6) and rats (13.6) with the respective ratio in cytoplasmic tRNA (11.8) we conclude that 5,6-dihydrouridine is also virtually quantitatively excreted in urine. Therefore, excreted 5,6-dihydrouridine is suitable as a marker to assess the whole body degradation rate of tRNA. Relative degradation rates of tRNA determined via excreted 5,6-dihydrouridine in urine are 4.7 times higher in rats (2.2 +/- 0.33 mumol/kg per day) than in human adults (0.48 +/- 0.05 mumol/kg per day) which is similar to the respective difference in the resting metabolic rate per weight unit.

Adenosine↗

PubMed1993

Myocardial viability: what do we need?

Coronary revascularization in patients with chronic coronary heart disease (CHD) or acute myocardial infarction (AMI) is mainly based on factors such as coronary anatomy, ventricular function, accompanying diseases and the patient's biological age. Rest- or exercise-induced ischaemia should be proven before a bypass operation or percutaneous transluminal coronary angioplasty. Although a significant amount of ischaemic but still viable myocardium is a necessary condition for successful revascularization, the detection of viable myocardium is of major importance in a rather small subset of patients. These are patients with hibernating (or a combination of hibernating and stunned) myocardium in whom the aforementioned parameters do not yield an unequivocal result. Thallium-201 myocardial scintigraphy with re-injection or rest-redistribution is an established, proven and cost-effective way of detecting viable myocardium. Other methods such as positron emission tomography with different tracers or technetium-99m sestamibi SPET are discussed and compared to thallium-201 SPET. In conclusion, the detection of ischaemic but still viable myocardium is of importance in only a rather small subset of patients with CHD. In this context thallium-201 myocardial SPET is and still remains the method of choice.

Heart↗

PubMed1993

Survival predictors in patients with a left ventricular ejection fraction of 10-30% receiving a coronary bypass: analysis of preoperative variables.

A total of 224 patients with angina pectoris and a left ventricular ejection fraction in the range of 10-30% (mean 24.2%) underwent coronary artery bypass grafting between April 1986 and August 1991. These patients received a mean (s.d.) of 2.9 (0.3) aortocoronary vein grafts. The overall operative mortality rate was 8.9%. The 1-, 2- and 3-year survival rates were 87.7%, 86.7% and 85.2%, respectively. Analysis of operative risk factors showed that patients with an end-diastolic left ventricular pressure > 24 mmHg were significantly more at risk (mortality rate 20.0%, P < 0.05) than those with an end-diastolic left ventricular pressure < or = 24 mmHg (mortality rate 6.2%). Patients with a perioperative cardiac index < 2.5 l min-1m-2 had higher mortality (25.4%) than those with a cardiac index > or = 2.5 l min-1m-2 (mortality 1.9%, P < 0.001). The operative mortality rate of patients with a cardiac index < 2.5 l min-1m-2 and an end-diastolic left ventricular pressure > 24 mmHg was 40.5%. Patients with a left ventricular ejection fraction of 10-20% were not significantly more at risk (P > 0.05) than those with a left ventricular ejection fraction of 21-30%.

Adult↗

PubMed1992

[Coronary revascularization in end-stage coronary heart disease in relation to assessment of myocardial vitality].

From 4/1986-12/1990, 177 pts. with endstage coronary artery disease (CAD) and left ventricular ejection fraction 10-30% received coronary artery bypass grafting (CABG). Preoperatively myocardial infarction rate was 1.5 (mean). Presupposition for CABGs was myocardial ischaemia at present demonstrated in myocardial viability test. 66.1% of the pts. had signs of ischaemia at e.c.g. after work. Additionally 97.6% of the pts. had myocardial ischaemia defined as redistribution in myocardial scintigraphy. Angina pectoris was present in 93.8% of the pts. preoperatively. 1-5 (mean 2.9) CABG per pt. were performed. 35 pts. received an internal mammaria bypass to the left coronary artery also. Operative mortality was 11.3% (1986-1990) and in 1990 alone 7.3%. Actuarial survival rate was calculated after one year to 87.4% after two years to 86.1% and after three years to 84.8%. Postoperatively all pts. were free from angina pectoris. 5 months after the operation e.c.g. after work was performed. The physical stress bearing area was increased to 82.7 Watt (mean) compared to 51.7 Watt (mean) preoperatively (p less than 0.001 s.). In conclusion pts. with endstage CAD and left ventricular ejection fraction 10-30% appeared to be good candidates for CABG with good prognosis and significant symptomatic improvement when signs of myocardial ischaemia are present preoperatively.

Aged↗