Biomedical subjects

M Schemper

Publications and source records attributed to M Schemper.

At least 91 records · Page 5Linked to original sources

PubMed1988

Vein bypass surgery for femoro-popliteal arteriosclerosis: influence of different risk factors on patient survival and the importance of anticoagulant treatment.

For femoro-popliteal arteriosclerosis the autologous saphenous vein graft implanted in reverse has evolved as the standard procedure, but the impact of postoperative anticoagulant treatment upon patient survival in particular remains uncertain. Patients undergoing elective surgery during the years 1970-86 (n = 668) were analysed using Kaplan-Meier estimates. This demonstrated that the preoperative status of the patient exerted a significant influence on the probability of survival (P less than 0.0001 Mantel). Anticoagulants started postoperatively significantly prolonged the life of the patients (P less than 0.0001). Of the various risk factors the patient's age had the most important influence (P less than 0.0001), whereas the presence or absence of diabetes mellitus (P less than 0.064) and the duration of the operation (P less than 0.407), were not significant. Using the proportional hazards regression model to test the validity of a prognostic factor, while other variables were checked, we found preoperative clinical status (P less than 0.0001), the patient's age (P less than 0.0001) and anticoagulant treatment (P less than 0.0001) to be of statistical importance.

Age Factors↗

PubMed1988

Alterations in nocturnal serum melatonin levels in humans with growth and aging.

The available data on potential alterations in serum melatonin (MLT) levels during a human lifetime are fragmentary and inconsistent. We, therefore, measured day- and nighttime serum MLT concentrations in 367 subjects (210 males and 157 females), aged 3 days to 90 yr. Blood samples were collected between 0730 and 1000 h and between 2300 and 0100 h. Serum MLT levels were measured by RIA. The mean nighttime serum MLT concentration was low during the first 6 months of life, i.e. 27.3 +/- 5.4 (+/- SE) pg/mL (0.12 +/- 0.02 nmol/L). It then increased to a peak value at 1-3 yr of age [329.5 +/- 42.0 pg/mL; (1.43 +/- 0.18 nmol/L)], and it was considerably lower [62.5 +/- 9.0 pg/mL; (0.27 +/- 0.04 nmol/L)] in individuals aged 15-20 yr. During the following decades serum MLT declined moderately until old age (70-90 yr of age), i.e. 29.2 +/- 6.1 pg/mL (0.13 +/- 0.03 nmol/L). This biphasic MLT decline follows 2 exponential functions with different slopes (from age 1-20 yr: r = -0.56; P less than 0.001; y = 278.7 X e -0.09x; from age 20-90 yr: r = -0.44; P less than 0.001; y = 84.8 X e -0.017x). The decrease in nocturnal serum MLT in children and adolescents (1-20 yr) correlated with the increase in body weight (r = -0.54; P less than 0.001) and body surface area (r = -0.71; P less than 0.001). At a later age (20-90 yr) there was no correlation among these variables. Daytime serum MLT levels were low and no age-related alterations were found. This study revealed major age-related alterations in nocturnal serum MLT levels. The negative correlation between serum MLT and body weight in childhood and adolescence is evidence that expansion of body size is responsible for the huge MLT decrease during that period. The moderate decline at older ages must derive from other factors.

Adolescent↗

PubMed1988

Primary hepatic cancer--the role of limited resection and total hepatectomy with orthotopic liver replacement.

Between 1977 and 1986, 172 patients with primary hepatic cancer were treated at the Department of Surgery I, University of Vienna Medical School. In 76 cases (80%) males, 20% females), cirrhosis of the liver was also present. Ninety patients underwent curative surgery (hepatic resection in 64, and liver transplantation in 26 cases). There were no early tumor stages. Forty-five large tumors were confined to one lobe, 42 involved both lobes, 3 even invaded adjacent structures, the majority (74%) being hepatocellular carcinomas. Forty-four of the 64 liver resections were performed in patients with otherwise normal livers (mortality 18%), while 20 patients had associated liver cirrhosis. In view of the extremely high mortality rates after extended liver resection, only limited local resections have been performed in cirrhotic malignancies since 1982 (mortality 25%). Perioperative mortality (25% overall) was due mainly to hepatic failure and sepsis; non-fatal complications occurred in 12 patients (26%). Seventeen of the 26 liver transplants were cirrhotic hepatomas. Nine deaths (34%) were caused by technical problems (graft failure, clotting disorder after massive transfusion) and systemic infections. The outcome for the patient after the immediate postoperative period was determined by tumor regrowth (residual liver tissue, graft, distant metastases) in both groups (median life expectancy 18.4 months after radical liver resection and 18.6 months after liver transplantation). Surgery is the only alternative for these patients (50% survival of untreated hepatoma: 2.6 months), improving both their quality of life and survival. We believe that in carefully selected candidates with non-resectable tumors liver replacement may be a useful alternative.

Carcinoma, Hepatocellular↗

PubMed1988

[Validation study of the Mannheim Peritonitis Index].

113 patients suffering from purulent peritonitis entered this retrospective study for evaluation of the prognostic value of the Mannheim Peritonitis-Index. There was no lethality below an index x = 21, between x = 21 and x = 29, it was 29% and lethality increased to 100% in patients with an index x greater than or equal to 30. Statistical validation showed that prognosis was correct in 93% for the index x = 27, with a sensitivity and specificity of also 93%. Between x = 21 and x = 29 prognosis of the MPI was correct in at least 65%. The MPI is shown as a prognostic index for peritonitis with high accuracy in individual prognosis, that could be easy routinely documented.

Adolescent↗

PubMed1988

[Stimulation of collagen synthesis in rabbit tendons by continuous extension stress].

In a series of three experiments we tried to find out early changes of mechanical properties and of collagen synthesis induced by continuous loading in rabbit tendons. Unphysiological elongation of the calcaneus tendon was performed by distraction of the osteotomized lower leg with the aid of an external minifixator. In the first experiment, the stretched tendons and the unstretched tendons of the contralateral legs were excised 24 hours postoperatively and compared. Collagen-synthesis was measured using 3H-Proline. After 24 hours' stretching a clear increase of 3H-Proline as a sign of collagen new-formation was found in only three out of five animals. In the second experiment, stress-strain measurements were performed after 24 hours of loading. In paired tests a clear difference was not found. Therefore, loading was extended to 48 hours in the third experiment. 3H-Proline was measured as well as the mechanical properties in paired tests. The median increase of the 3H-Proline level was significant: 44%. Stress-strain behaviour was investigated using a special testing equipment. This enables us to perform strain controlled tests in order to find out the mechanical properties of the different specimen.

Animals↗

PubMed1987

[Effect of risk factors on early and long-term regional results following kidney transplantation].

An observational study by multifactorial statistical analysis was undertaken on 785 kidney transplants. Risk factors in first transplants for primary non-function are cold ischaemic time, donor centre and acute rejection, with a non-function rate of 8% and a delayed function of 37%. Risk factors for transplant survival are bad match, no preoperative transfusions, age of recipient below 40 years, male sex, diabetes, conventional immunosuppressive therapy and cadaver donors. Donor centre and delayed primary function have no influence on long-term kidney function. The analysis revealed additive effects of various risk factors. This has to be taken into account in recipient-selecting policy.

Cadaver↗

PubMed1987

[Role of postoperative anticoagulant treatment following femoro-popliteal venous bypass. Interim evaluation of a controlled clinical study].

Eighty-eight patients underwent a classical reversed saphenous vein graft for femoro-popliteal occlusive disease and were enrolled in a controlled clinical trial. During the second postoperative week the patients were allocated randomly into one of two groups: group I consisted of 42 patients who received dicumarol and group II (46 patients) served as a control group without any anticoagulant treatment. The mean follow-up time was 24 months. After 12 months the cumulative patency rate was 82%, after 18 months 76% and after 24 months 76%; for patients receiving dicumarol treatment the respective figures were 92%, 86% and 86% and for those with no treatment 70%, 67% and 67%, the difference being significant. When the bypass operation was performed for limb salvage (clinical stages III and IV) the overall results were worse (12 months: 72%, 18 months: 68%, 24 months: 68%) than in stages II, II-III (12 months: 90%, 18 months: 85%, 24 months: 85%). In limb salvage surgery the positive effects of anticoagulant treatment were significant (with treatment: 12 months 87%, 18 months 86%, 24 months 86%; without treatment: 12 months 58%, 18 months 54%, 24 months 54%).

Aged↗

PubMed1987

[Stomach cancer in Austria. Epidemiology and pathogenesis].

The declining incidence of gastric cancer is a worldwide phenomenon and this development over many years applies to Austria too. One reason for this decline probably lies with altered dietary customs. Regional differences, a main argument for the importance of exogenous factors in the pathogenesis are also discernible in Austria. The decrease in death rates from gastric cancer cannot be attributed to improved survival and early diagnosis is still a rare event.

Aged↗

PubMed1987

Prognostic significance of steroid hormone receptors and histopathological characterization of human breast cancer.

Since breast cancer is a heterogeneous disease, evaluation of prognosis is an obvious problem. The prognostic significance of several pathological criteria including tumor grading according to WHO, steroid hormone receptor status, histological tumor type, tumor size, and axillary lymph node involvement have been investigated. The single parameters with the strongest prognostic significance were axillary lymph node status, tumor grading, and estrogen receptor status. A significant direct correlation exists between tumor grading and steroid hormone receptors, but nevertheless on stratified analysis both factors independently affected the risk of death. Tumor size had weak prognostic importance and histological tumor types failed to show any statistically significant differences with regard to survival.

Adult↗

PubMed1987

Testicular cancer: prognostic implications of vascular invasion.

In a retrospective study the primary tumors of 33 patients with seminomas and 53 with nonseminomatous germ cell tumors were re-evaluated for vascular invasion. The significance of vascular invasion was analyzed in respect to the appearance of visceral metastases and the effect of adjuvant chemotherapy. Vascular invasion was demonstrated in 27 per cent of the patients with seminomas and 53 per cent with nonseminomatous germ cell testis tumors, while visceral metastases appeared in 9 and 32 per cent, respectively. Without adjuvant chemotherapy all 13 patients with nonseminomatous germ cell testis tumors and vascular invasion had metastases, compared to only 3 of 13 without vascular invasion (p less than 0.0005). Of 9 patients with seminoma and vascular invasion 3 had tumor progression, compared to 1 of 24 without vascular invasion (p greater than 0.05). With adjuvant chemotherapy only 1 of 15 patients (7 per cent) with nonseminomatous germ cell testis tumors and vascular invasion had metastases, compared to 100 per cent of 13 without this treatment. No significant correlation was noted between pT stage versus vascular invasion and pT stage versus tumor progression. The results demonstrate the importance of vascular invasion in the staging of and choice of treatment for early nonseminomatous germ cell testis tumors.

Adolescent↗

PubMed1987

The place of profundaplasty in the surgical treatment of superficial femoral artery occlusion.

One-hundred and sixty-three patients in whom an isolated profundaplasty was performed as treatment for superficial femoral artery occlusion were evaluated for postoperative improvement, taking into consideration the degree of stenosis of the profunda origin and the patency of peripheral vessels. One-hundred and eleven (68.1%) patients achieved clinical improvement. Fifty-two patients had to undergo amputation (27 below the knee and 19 above the knee) or distal reconstruction (6 patients) because of unrelieved ischaemia. In patients with Fontaine stage II and III disease (89% and 70% respectively) improvement was observed more often than in those with stage IV disease (53%). Half of the patients had an increase of the resting systolic ankle-brachial arterial pressure index, but the rise was only slight (0.12 +/- 0.1). While radiological information of the presence and degree of a stenosis had little influence on the operative outcome stenosis at the origin of the profunda, when seen and described at operation, resulted in a more frequent improvement in the clinical state and systolic ankle-brachial arterial pressure index. A patent popliteal artery was not necessary for a favourable outcome but the number of patent tibial arteries was important. Whenever two tibial vessels were patent, relief was achieved in 75% of the cases: the existence of one patent tibial artery produced improvement in 64% but if all were occluded only 31% showed improvement. In cases of severe ischaemia, success following profundaplasty is limited and the results are often inadequate. If at least one tibial artery is patent, the alternative is a femoro-crural reconstruction.(ABSTRACT TRUNCATED AT 250 WORDS)

Amputation, Surgical↗

PubMed1987

[Therapeutic and prognostic results of a prospective multicenter ovarian cancer study of FIGO stages I and II].

Between April 1980 and December 1985 a prospective controlled and randomized multicenter study of 124 assessable patients with stage I and II epithelial ovarian carcinomas was carried out. The aims of this study were first to verify the value of adjuvant irradiation therapy or combined chemo-irradiation therapy, and second to evaluate the importance of different prognostic factors such as age, histology, tumor grading, and tumor stage. Patients with well-differentiated stage IA tumors did not receive any therapy; patients with undifferentiated stage IA tumors were randomized to "no therapy" or irradiation therapy; patients with stage IB, IIA, and IIB tumors were treated by either irradiation or a combined chemo-irradiation therapy consisting of Adriamycin/Cyclophosphamide. In patients with stage IC and IIC ovarian carcinomas a combined irradiation-polychemotherapy was instituted, consisting either of Adriamycin/Cyclophosphamide or of Adriamycin/Cisplatin. Because of the low number of patients and the relatively good prognosis no definite evaluation of the individual therapeutic modalities could be done. An analysis of all patients showed that differentiation between stage I and stage II ovarian carcinomas is the single most important prognostic factor. After a mean observation time of 42 months (8-71 months) for stage I tumors a 91% probability of three-year survival was attained, in comparison with 57% for stage II tumors. It has not been definitely established that there is a need for adjuvant therapy for stage I tumors and this should be confirmed by further studies. Because of the unfavorable prognosis for patients with stage II ovarian cancer, these patients should be given the same polychemotherapy, including Cisplatin, as patients with advanced ovarian carcinomas.

Antigens, Neoplasm↗

PubMed1987

A pharmacological dose of melatonin increases PRL levels in males without altering those of GH, LH, FSH, TSH, testosterone or cortisol.

Since reports on the influence of melatonin (aMT) on the human endocrine system are scant and inconsistent, the effect of an acute, pharmacological dose of aMT on various hormone levels in healthy males was examined in 3 different experiments. Experiment I: 80 or 240 mg of crystalline aMT were administered per os to 8 volunteers. Before, during and after this treatment, serum levels of aMT, PRL, LH, FSH and testosterone were examined. Although aMT increased at least 1,500-fold over basal levels, only PRL was significantly and consistently elevated after aMT treatment, whereas serum levels of the other hormones were not altered. Experiment II: in 2 subjects, the pulsatile secretion pattern of LH was monitored for 6 h before and 6 h after aMT administration (240 mg p.o.). Neither the amplitude nor the frequency of LH pulses was influenced by the pineal hormone. Experiment III: in 14 volunteers, serum PRL, GH, TSH and cortisol concentrations were examined, once after oral administration of 240 mg aMT and once after placebo. Serum PRL levels were significantly higher after aMT than after placebo; GH showed a slight but not significant trend towards elevation after aMT, whereas other hormones were not altered. An acute pharmacological dose of aMT causes isolated elevation of serum PRL levels and may slightly increase GH. Hormones of the pituitary gonadal axis as well as TSH and cortisol are not altered by aMT.

Adult↗

PubMed1987

The influence of anticoagulant treatment on the probability of function in femoropopliteal vein bypass surgery: analysis of a clinical series (1970 to 1985) and interim evaluation of a controlled clinical trial.

During the years 1970 to 1985, 463 patients with obliterative atherosclerosis at the femoropopliteal level underwent elective surgery. The operation performed was an autologous saphenous vein bypass using the reversed technique. The vascular surgical treatment was documented in reasonable detail (both baseline and follow-up) in accordance with the documentation system of the Austrian Society of Vascular Surgery. On-line data entry with use of SAS data-base management software was used. The patency curves were estimated in accordance with the Kaplan-Meier method; possible differences were checked by means Breslow's and Mantel's tests. The preoperative clinical status (claudicants, n = 200; limb salvage, n = 263) influenced the postoperative results in a statistically significant manner (Breslow p less than 0.01; Mantel p less than 0.03). All the other risk factors analyzed (site of distal anastomosis above versus below the knee, n = 231, and n = 232, respectively; Breslow p less than 0.58, Mantel p less than 0.58. Presence [n = 122] or nonpresence [n = 341], of diabetes mellitus [Breslow p less than 0.77, Mantel p less than 0.68]; smoking habits [nonsmokers, n = 93, smokers n = 370, Breslow p less than 0.68, Mantel p less than 0.69;]) did not reach statistical significance. Anticoagulant treatment (n = 101) had no effect (Breslow p less than 0.93, Mantel p less than 0.72), even when the therapy was restricted to cases with disease at advanced clinical stages (stages III, IV; n = 50; Breslow p less than 0.55, Mantel p less than 0.95). On the basis of these analyses, a prospective trial was initiated in 1979. Eighty-eight patients were studied; those in group I (n = 42) received dicumarol, and those in group II (n = 46) were controls who did not receive anticoagulant treatment. At present, the median follow-up time is at 30 months. Treatment with dicumarol favorably influenced graft patency (Breslow, p less than 0.03, Mantel p less than 0.07; one-tailed tests). The patients' preoperative clinical status affected the results of surgery (Breslow p less than 0.03, Mantel p less than 0.02; one-tailed tests). In relation to the preoperative clinical status, a therapeutic effect was observed in stages III and IV (n = 45; Breslow p less than 0.03, Mantel p less than 0.07; one-tailed tests), while no effect of therapy was demonstrable in claudicants (n = 43; Breslow p less than 0.3, Mantel p less than 0.4; one-tailed tests).(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗

PubMed1987