Biomedical subjects

H Hirche

Publications and source records attributed to H Hirche.

At least 91 records · Page 5Linked to original sources

PubMed1990

Survival rates in patients with differentiated thyroid carcinoma. Influence of postoperative external radiotherapy.

Nine hundred thirty-two patients with papillary and follicular thyroid carcinomas were seen at the Departments of Medicine, Surgery, and Radiology of the University of Essen, Essen, Germany, between 1970 and 1986. In addition to standard treatment by surgery, radioactive iodine and medical thyroid stimulating hormone (TSH) suppression, 346 patients had received conventional external irradiation to the neck (mostly 40-60 Gy) before referral to our institutions, whereas 586 patients had not received radiotherapy. From the follow-up data of these patients, survival rates were calculated separately for tumor Stages T1 (n = 203), T2 (n = 552), and T3/T4 (n = 277) using life-table analysis. Distribution of risk factors (histologic type of tumor, grading of malignancy, presence of distant metastases, age and sex) was similar in all groups with the one exception, that the radiotherapy patients with Stage T3/T4 were older. There was no significant difference in the life expectancy of irradiated and not irradiated patients by Breslow and Mantel-Cox tests. In Stages T1, T2, and T3/T4, 75% of the radiotherapy patients survived for 10.6 +/- 0.32, 11.5 +/- 0.61, and 6.71 +/- 0.85 years, respectively; the figures for the nonirradiated patients were 9.4 +/- 0.17, 10.8 +/- 0.37, and 6.26 +/- 0.51 years, respectively. When survival rates were calculated separately for patients with Stage T3/T4 older and younger than 40 years, there was no obvious effect of radiotherapy in the younger group, whereas in the older patients, improvement of survival by radiation just failed to reach statistical significance (P less than 0.09). In conclusion, this retrospective analysis failed to prove that survival is prolonged in patients with differentiated carcinoma by administration of conventional external radiotherapy after surgery. A benefit to older patients with locally advanced tumors has still to be demonstrated.

Adenocarcinoma↗

PubMed1990

Does noradrenaline influence the extracellular accumulation of potassium, sodium, calcium, and hydrogen ions ([K+]e, [Na+]e, [Ca2+]e, [H+]e) during global ischemia in isolated rat hearts?

The influence of noradrenaline (NA) on net cation fluxes during global ischemia (gI) was investigated in isolated rat hearts. The hearts were perfused according to the Langendorff technique and left ventricular pressure (LVP), the first derivative of the LVP (dP/dtmax, dP/dtmin), coronary perfusion pressure (CPP), and heart rate (HF) were measured. In the control group, the perfusion medium was either Krebs-Henseleit's solution (KHS), or KHS and tetramethylammonium-chloride (TMA; 100 microM). In this study TMA was used as a marker to determine changes in the extracellular space (ECS) size during gI. The hearts were subjected to 40 min of gI. Changes in the size of the ECS, and net cation movements were calculated during the first 20 min of gI. In treated hearts, NA (50 nM) was added to the perfusate 15 min before the onset of gI. Extracellular concentrations of K+, Na+, Ca2+, H+, and TMA were measured using double-barreled polyvinyl-chloride (PVC) mini-electrodes. Relative changes in the ECS size and net cation movements were calculated from the extracellular TMA and cation concentrations. In separate experiments, the hemodynamics and lactate overflow of treated hearts were compared with control hearts prior to and following a brief period (1 min) of gI. Addition of NA to the perfusate significantly: 1) increased CPP, LVP, dP/dtmax, dP/dtmin, and HF prior to the onset of gI, and increased cell swelling during gI; 2) diminished K(+)-release from the cells, but significantly increased the influx of sodium and calcium into the intracellular space (ICS); 3) increased lactate overflow prior to and following 1 min of gI. We assume that catecholamines increase ECS shrinkage before and during gI, probably by increased lactate production. NA stimulates the Na+/K+ pump, thereby reducing [K+]e accumulation. The increased [Ca2+]i and intracellular acidification promote sodium entry into the cells during gI.

Animals↗

PubMed1990

Effects of anoxia on K and Ca currents in isolated guinea pig cardiocytes.

Whole cell currents were measured in isolated cardiocytes of guinea pig under anoxic conditions (pO2 less than 0.5 torr). After 2 to 32 (mean 11.2) minutes of anoxia, time independent outward currents developed gradually which had a linear current-voltage relation between -100 and +20 mV and reversed at the resting potential of the cells (-82 to -90 mV). After 20 to 170 (mean 38) seconds, the amplitude of these outward currents saturated (3.6 +/- 0.5 nA at +10 mV, n = 23). Reoxygenation within one minute after the appearance of the first extra outward currents led in most cells (greater than 90%) to their complete disappearance in 2 to 4 (mean 2.87, n = 15) seconds. Ca currents were not affected at the time when the first extra outward currents occurred. It is concluded that (i) the anoxia-induced outward current is carried by K+ ions probably through KATP channels which open at intracellular ATP concentrations below 1 mmol/l (Noma and Shibasaki 1985) and (ii) this degree of ATP depletion does not affect normal Ca channel function.

Animals↗

PubMed1990

Continuous determination of extracellular space and changes of K+, Na+, Ca2+, and H+ during global ischaemia in isolated rat hearts.

Isolated rat hearts were perfused according to the Langendorff technique and prepared to allow the measurement of left ventricular pressure (LVP), the first derivative of LVP (dP/dt), coronary perfusion pressure (CPP) and heart rate (HR). The hearts were perfused with a modified Krebs-Henseleit solution (KHS; control group) or KHS containing tetramethylammonium-chloride (TMA; 100 microM), which did not influence heart haemodynamics or extracellular potassium accumulation during global ischaemia (GI). TMA was used as a marker to determine changes in the size of the extracellular space (ECS) during 60 min of GI. Extracellular concentrations of K+, Na+, Ca2+, H+ and TMA were measured using double-barreled polyvinyl chloride (PVC) mini-electrodes. Relative changes in the ECS size and net cation movements were calculated from the extracellular TMA and cation concentrations. After 60 min of GI ECS decreased by 74% due to a water shift into the intracellular space (ICS). Within 10 s after the onset of GI extracellular potassium concentration increased in a typical triphasic pattern. A biphasic net efflux of K+ was maximal 2 and 15 min after the onset of ischaemia interrupted by a maximal uptake after 7 min, probably due to the stimulation of the Na+/K+ ATPase. The changes in extracellular sodium and calcium concentrations were biphasic; showing an initial increase occurring approximately during the first 20 min after the onset of GI followed by a decrease. Despite the initial increase of extracellular Na+ and Ca2+ maximal net influx of Na+ and Ca2+ were calculated after 2 and 19 min of GI. Accumulation of H+ in the extracellular space occurred mainly during the first 20 min of GI. It is concluded that, (1) TMA is a useful marker for continuous measurement of changes in the size of the ECS during GI; (2) Changes in extracellular ion concentration are influenced markedly by a water shift from the ECS into the ICS; (3) Stimulation of the Na+/K+ pump causes a transient net uptake of K+ and reduces the net influx of Na+; (4) Ca2+ uptake is decreased transiently probably by increased Ca2(+)-ATPase activity; (5) Energy dependent protective mechanisms for the maintainance of intracellular ionic homeostasis are exhausted after approximately 15 to 20 min of GI in isolated working rat hearts.

Animals↗

PubMed1990

Changes in mitotic rate and cell cycle fractions caused by delayed fixation.

The mitosis frequency and flow cytometric data of malignant neoplasms are important, both for diagnosis and for prognosis. It is unclear to what extent these factors are affected by a delay in the fixation of tumor biopsies. We have thus studied the mitotic activity and DNA content in human soft-tissue sarcoma xenotransplants, fixed for periods of 5 minutes and 3, 6, 9 and 12 hours after biopsy. On average, the mitoses counted by two observers were 13% and 10% below initial values after 3 hours, and decreased by 46% and 39% after 12 hours. The mitosis decrease was related to the degree of mitotic activity of individual tumors, and was minimal in the sarcomas with the lowest mitotic rate. These results were reproducible. However, numerous pyknotic mitotic figures were observed, so the decrease in counts is largely due to their reduced identifiability, and only partly attributable to a completion of the cell cycle. Well-preserved mitotic figures demonstrable after 12 hours appear to indicate that the proliferation activity only gradually decreases in unfixed biopsies. The flow cytometric data did not change substantially; only a slight increase in the G2 + M-phase fraction was observed. General conclusions from the results are limited by the fact that the investigated sarcomas had a higher mitotic activity than most carcinomas. Nevertheless, early fixation of biopsies is desirable to accurately measure mitosis counts for the grading of malignancy.

Analysis of Variance↗

PubMed1990

The ontogenesis of skin and organ characteristics in the Syrian golden hamster. I. Skin compartments and subcutaneous adipocytes.

The quantitative relations between the 4 skin compartments [epidermis, stratum (str.) papillare, str. reticulare, panniculus carnosus], the hair follicle density and adipocyte size were investigated histometrically in a total of 464 golden hamsters of both sexes of the acromelanic white inbred strain Bio 1.5 and agouti coloured outbred strain Han:AURA. The overall regular course of ontogenesis from the 1st to the 365th day of life showed discontinuous impairments of the skin layer thickness in the shoulder and sacral region due to the spontaneous growth cycles of hair. Active phases of hair growth could be determined on days 15-25, 50-60 and 80-110 from measurements of the hair follicle density as well as skin thickness. In particular, the thickness of the str. reticulare was closely correlated to the growth cycles. By contrast, the epidermis, str. papillare and skin muscle thickness showed an age-dependent development. Also, no correlation was found between the size of inguinal adipocytes and hair growth cycle, which is in contrast to the data from the literature for small laboratory rodents. Only differences in skin muscle thickness could be found in the sites studied in the shoulder and sacral regions. Overall, the skin compartments, the skin follicle density and adipocyte size were found to be stable to effects such as animal strain, sex and skin localization.

Adipose Tissue↗

PubMed1990

Naftidrofuryl in the treatment of mild senile dementia. A double-blind study.

After a wash-out period of four weeks 51 patients with mild to moderate senile dementia were treated with either 600 mg naftidrofuryl (n = 23) daily per os or placebo (n = 28) over an eight-week period. When classified according to Hachinski's score, 24 patients were found to be suffering from senile dementia of Alzheimer's type (SDAT), whereas 27 patients presented with vascular dementia (MID). During wash-out and the treatment period the somatic and social symptoms of the disease were assessed by the AGP score. Cerebral performance was evaluated by a battery of tests measuring memory, concentration, psychomotor coordination and degree of depression. Electrical activity of the brain was estimated by a power-spectral analysis of EEG. In the total study group, the naftidrofuryl group showed a significantly better improvement in the results of the psychometric test battery, which was the primary variable during treatment. A parallel development was to be found in the AGP score and electrical brain function. When results of subgroups were analyzed according to the etiopathogenetic background of patients with SDAT, it was possible to show that naftidrofuryl affected psychopathometry and EEG-parameters while patients with MID responded to naftidrofuryl with changes in AGP score and EEG variables. These findings indicate the importance of etiopathologic features in performing studies with nootropic drugs in obtaining information on possible different actions in patients with different kinds of senile dementia.

Age Factors↗

PubMed1990

[Cross-sectional study of elementary school children for assessing suspected effects of regional hemato-toxic environmental pollutants].

To investigate the suspicion of an increased incidence of leukopenia in school children living in the more industrialised northern region of the city of Essen, blood counts of these children were compared to those of pupils from the southern region in a two-phased study. In 469 1st and 2nd grade children, neither the mean leukocyte count nor the number of individual abnormal results differ between the two regional groups. A difference in the mean hemoglobin value found in the first series of investigations could not be reproduced in a control study of 255 children, the analysis of the data pointing to a methodological reason for the difference. Feasibility, planning and interpretation of results of such a cross-sectional study are discussed.

Air Pollutants↗

PubMed1990

[Hemodynamics and myocardial energy balance in coronary surgery patients during high-dose fentanyl-pancuronium anesthesia and modified neurolept-pancuronium anesthesia].

In 8 patients with coronary artery disease (CAD) classed as NYHA II or III, anesthesia was induced with high-dose fentanyl (0.05 mg/kg) and pancuronium (0.1 mg/kg). The patients were ventilated normally with the aid of a mask (O2: air 1:1, tidal volume 10 ml/kg with a rate of 10/min) for 5 min and then intubated. In 8 further patients with CAD NYHA class II or III, anesthesia was induced with 0.02 mg/kg flunitrazepam, N2O/O2 1:1 and isoflurane 0.5 vol%; they were relaxed with pancuronium (0.1 mg/kg) in combination with a bolus of 0.005 mg/kg fentanyl. These patients were also ventilated normally for 5 min and then intubated. Measurements of cardiovascular dynamics included cardiac output (CO), heart rate (HR), arterial pressure (AP), pulmonary artery pressure (PAP), pulmonary capillary wedge pressure (PCWP), right atrial pressure (RAP), myocardial blood flow (MBF), and arterial and coronary sinus oxygen and lactate contents. Cardiac index (CI), stroke volume index (SVI), total peripheral resistance (TPR), myocardial oxygen consumption (MVO2), coronary vascular resistance (CVR), coronary perfusion pressure (CPP), myocardial oxygen content difference (AVDO2cor) and myocardial lactate extraction rate (LE) were calculated from standard formulas. Measurements and an electrocardiogram were taken before anesthesia, after induction of anesthesia and after intubation. The hemodynamic parameters HR, AP, CI, CPP were relatively stable in patients anesthetized with high-dose fentanyl and pancuronium, whereas we found greater decreases in these parameters with the balanced anesthesia technique. Determinants of myocardial oxygen demand were higher in the high-dose fentanyl group; therefore, myocardial blood flow and oxygen consumption did not decrease to the same extent as in the balanced anesthesia group.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1989

[Sequential induction chemotherapy and radiation treatment of inoperable small cell bronchial cancer. Results of a prospective randomized study].

To study the potential benefit of sequential chemotherapy in inoperable small cell lung cancer (SCLC), from 1982 to 1986 ninety-one patients with histologically proven and previously untreated SCLC (median age: 53 years; median Karnofsky status: 80%) were randomly assigned to an initial therapy with adriamycin (since 1984 epirubicin), cyclophosphamide, vincristine (ACO resp. EPICO) or etoposide/cisplatin (VP16/DDP). Treatment courses were repeated every 3 weeks for a total of less than or equal to 6 courses with a crossover after a maximum of 3 cycles of either regimen. Limited disease (LD) patients with bronchoscopical, computertomographical and (re-) mediastinoscopical complete remission (CR) randomly received either a thoracic irradiation with 40 Gy or observation only. Overall, 60 out of 85 evaluable patients achieved an objective remission. A CR was observed in 24/51 patients (47%) with limited disease, and in 8/34 patients (24%) with extensive disease. Both, ACO (EPICO) and VP16/DDP were equally effective as initial and second-line therapy. Moreover, after failure to the initial therapy an objective remission could be achieved in 13% of the patients following the alternative second line combination. In 28% of LD patients with an otherwise complete remission residual tumor was detected by (re-) mediastinoscopy. Median survival times were 14 (CR: 16) months in LD patients and 10 (CR: 15) months in ED patients. At present, median survival is significantly improved in irradiated versus non-irradiated LD patients (25 vs. 13 months, p less than 0.04). The remission rates and median survival times observed in this study are comparable to those of a historical control group treated with ACO plus radiotherapy alone.

Adult↗

PubMed1989

High-dose medroxyprogesterone acetate in advanced breast cancer. Clinical and pharmacokinetic study with a combined oral and intramuscular regimen.

Seventy-five patients with advanced and intensively pretreated breast cancer received high-dose medroxyprogesterone acetate (MPA) using a schedule consisting of an intramuscular (IM) loading dose (1 g MPA IM days 1 to 10) and an oral maintenance treatment (200 mg/day three times a day) thereafter. A reinduction was performed in part of the responding patients at time of early relapse (1 g MPA IM for 10 consecutive days). MPA serum levels above 100 ng/ml were achieved during induction treatment and maintained for 3 to 4 months during the oral phase of therapy before decreasing to approximately 50 ng/ml. Two complete remissions (duration, 17.2 and 62 months), 15 partial remissions (median duration, 7 months), and 21 cases of disease stabilization (median duration, 5.5 months) were achieved. The median survival time was significantly longer for responders (19.9 months) than nonresponders (4.8 months). Although a higher proportion of postmenopausal patients responded, the remission duration in premenopausal women was remarkably long. Favorable sites of response were soft tissue, lymph nodes, and bone lesions. Reinduction treatment yielded a second response (two partial remissions, three no change) in five of six patients indicating that high-dose conditions were necessary to maintain response. This schedule allows to restrict higher doses of MPA on a long-term basis to responding patients.

Administration, Oral↗

PubMed1989

[The effect of pancuronium and norcuron on hemodynamics, coronary circulation and myocardial oxygen consumption in coronary surgery patients].

The effects of the non-depolarizing muscle relaxants pancuronium (Pancuronium) and vecuronium (Norcuron) (0.1 mg/kg) on myocardial blood flow, myocardial oxygen consumption, myocardial lactate balance, cardiovascular dynamics and electrocardiogram were studied in two groups of eight patients undergoing coronary artery bypass surgery. After an introduction of anaesthesia with 0.015-0.02 mg/kg rohypnol, isoflurane (0.5 Vol%) and N2O/O2 neuromuscular blockade was induced with pancuronium or vecuronium combined with a single dose of 0.005 mg/kg fentanyl. Measurements and electrocardiogram were performed before anaesthesia, in steady state of anaesthesia and after relaxation with pancuronium or vecuronium, combined with fentanyl. The measurements consisted of heart rate (HR), cardiac index (CI), stroke volume index (SVI), mean arterial pressure (AP), total peripheral resistance (TPR), pulmonary arterial pressure (PAP), pulmonary capillary wedge pressure (PCWP), right atrium pressure (RAP), myocardial blood flow (MBF), coronary vascular resistance (CVR), myocardial oxygen consumption (MVO2), coronary ateriomixed venous oxygen content difference (AVDO2cor), myocardial lactate extraction (LE) and rate pressure product (RPP). In the vecuronium group heart rate (HR) decreased significantly greater (21%) than in the pancuronium group (9%). Therefore myocardial oxygen consumption (MVO2) and coronary blood flow (CBF) diminished more in the vecuronium (48% resp. 35%) than in the pancuronium group (31% resp. 18%). The higher metabolic demand in the pancuronium group induced a significantly lower coronary vascular resistance (CVR). All the other hemodynamic parameters did not differ significantly in both patients groups. In all the patients we could not observe ST-segment depressions or elevations in the ECG, increases of PCWP or myocardial lactate productions.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1989

Effects of carvedilol on left ventricular function and arrhythmias during repeated short-time myocardial ischemia in experimental pigs.

The effects of carvedilol, a new vasodilating beta-blocking drug, were studied in experimental pigs during short-term acute myocardial ischemia. In 21 anesthetized pigs 0.01, 0.03, and 0.1 mg/kg b.w. carvedilol was studied during repeated 2-min distal LAD-occlusions and a 60-min-period of ischemia. Left ventricular volume was continuously measured by the impedance catheter method. Intravenous administration of 0.01 mg/kg carvedilol resulted in a significant decrease of heart rate (-13%), dp/dtmax (-32%), and ejection fraction (-9%), slight changes of systolic pressure (-3%), and an increase of vascular resistance (+24%), indicating a beta-blocker effect without vasodilation-while the first vasodilatory effect was found at a dose of 0.1 mg/kg. During ischemia carvedilol had no influence on the time-course or the extent of systolic bulging of the ischemic myocardium, but the ischemia-induced decrease of left ventricular ejection fraction was diminished. Both during short-term ischemia, as well as during the 60-min-ischemia-period carvedilol significantly reduced ventricular premature beats. During the 60-min-ischemia-period activation delay measured from local DC-electrograms of the ischemic myocardium, as well as the occurrence of activation block were not altered by carvedilol, as was the incidence of ventricular fibrillation (69%). We conclude that at low dosages the beta-blocking effect of carvedilol exceeds the vasodilating properties. This may also hold true in patients with cardiac failure; they are more sensitive to beta-blocking drugs. During ischemia carvedilol slightly reduces the ischemia-dependent decrease of global ventricular function and it has an antiarrhythmic effect. Therefore, it may be protective in patients with acute myocardial infarction.

Adrenergic beta-Antagonists↗

PubMed1988

Is there any clinical relevance of serial determinations of serum carcinoembryonic antigen in small cell lung cancer patients?

Carcinoembryonic antigen (CEA) serum concentrations were serially determined by an enzyme immunoassay before, during, and after chemotherapy and radiotherapy in 129 male patients with small cell lung cancer (SCLC). Pretherapeutic CEA concentrations were as follows: 2.5 ng/ml or less for 37% of the patients; greater than 2.5 but less than or equal to 5 for 27%; and greater than 5 for 36%. Before therapy, CEA levels in patients with extensive disease (median value, 5.8 ng/ml) were higher than those in patients with limited disease (3.0 ng/ml; P less than 0.01). Median survival in patients with pretherapeutic CEA titers of 5 ng/ml or less (median survival, 14.3 months) was significantly longer than in patients with CEA levels greater than 5 but less than or equal to 10 and CEA levels greater than 10, respectively (8.3 and 9.7 months; P less than 0.01). Patients with pretherapeutic CEA levels greater than 10 ng/ml showed a significant decrease (P less than 0.01) of CEA while reaching partial remission (PR) or complete remission (CR). In five of 16 evaluable patients, a continuous increase of CEA titers was seen starting at least 3 months before relapse could be defined by clinical, radiologic, or endoscopic means. However, the number of patients for whom CEA serum determinations reliably indicate stage of disease and outcome of therapy is small (at best, 10% of all SCLC patients), and pretherapeutic CEA level cannot be used for individual prognosis. Moreover, it is still uncertain whether earlier detection of relapse in SCLC can improve the therapeutic results. So far, the clinical relevance of serial CEA serum determinations in SCLC patients is rather low.

Adult↗

PubMed1988

The effect of desipramine on ischemia-induced changes in extracellular K+, Na+, and H+ concentrations and noradrenaline release in the isolated rat heart during global ischemia.

Isolated Langendorff-perfused rat hearts set up to allow measurement of mechanical myocardial function (according to Bardenheuer and Schrader) were subjected to 60 min of global ischemia (gI). The hearts were perfused with a modified Krebs-Henseleit solution (KHS; control group) or KHS with desipramine (DMI group) 100 nM. Extracellular concentrations of K+, Na+, and H+ were determined using ion-selective membrane polyvinyl chloride (PVC) minielectrodes. The noradrenaline (NA) release was estimated by analyzing the NA overflow during a 10-min reperfusion period, using high pressure liquid chromatography (HPLC). Control hearts and DMI-treated hearts showed no differences in mechanical performance prior to gI. In control hearts, the onset of gI resulted in a rapid triphasic [K+]e accumulation (an increase from 4.25 +/- 0.25 to 8.76 +/- 0.37 mmol/L during the first 3.5 min, a decrease to 8.06 +/- 0.34 mmol/L until the seventh min, and a further increase to 33.0 +/- 2.42 mmol/L at 60 min), a rapid increase in [H+]e (45.9 +/- 2.3 to 1314.5 +/- 214 nmol/L during 23 min), and a slight initial increase of [Na+]e (138.8 +/- 0.4 to 141.9 +/- 0.8 mmol/L within 8 min) followed by a long-lasting decrease (119.1 +/- 4.5 mmol/L at 60 min). Treatment with DMI had only slight effects on ionic redistribution during the course of ischemia. The [K-]e and [H-]e accumulation tended to be diminished, whereas [Na-]e values were slightly higher in the course of gI compared to the control group.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1988

Effect of propranolol on early postischemia arrhythmias and noradrenaline and potassium release of ischemic myocardium in anesthetized pigs.

In anesthetized open-chest pigs, DL- or D-propranolol (1 mg/kg i.v.) was administered 15 min prior to ligation of the left anterior descending coronary artery (LAD) about halfway from its origin. Sequential myocardial tissue samples were obtained before and after LAD occlusion. The samples were analyzed histofluorimetrically to determine the density of catecholamine containing neurons (quantified morphometrically), and radioenzymatically for total tissue noradrenaline content. The extracellular K+ concentration was measured using K+-sensitive polyvinyl chloride (PVC)-membrane electrodes on the surface of the ischemic myocardium. Under control conditions, ventricular arrhythmias (VA) occurred in a typical 1a and 1b phase. Pretreatment with propranolol diminished the number of VA generated in the 1b phase but not those in the 1a phase; however, these differences were statistically not significant. Neither pretreatment with DL- nor D-propranolol influenced the time course or probability of development of ventricular fibrillation (VF). Coronary artery occlusion led to a significant reduction in noradrenaline concentration of the ischemic myocardium in control animals (from an initial concentration of 526 +/- 65 ng/g w/w to 368 +/- 75 ng/g w/w) within the first 5 min of ischemia, whereas noradrenaline concentration remained nearly unchanged in drug-treated animals (from 838 +/- 86 to 811 +/- 61 ng/g w/w in the DL group and from 701 +/- 36 to 709 +/- 31 ng/g w/w in animals that received D-propranolol.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia↗

PubMed1988

[Pretherapeutic prognostic factors in small cell bronchial cancer].

Two hundred and thirty patients with histologically proven small cell lung cancer--133 patients with limited disease and 97 patients with extensive disease--were treated from 1979 to 1986 in 3 prospective clinical trials at a single institution. Univariate and multivariate statistical analyses (Cox-models) were used to determine whether pretherapeutic factors can be used to predict survival and long-term survival. Extent of disease, determined by pretherapeutic staging, turned out to be the most significant prognostic parameter. Survival beyond 2 years was almost exclusively confined to patients with limited disease. Further independent predictors of survival duration in patients with limited disease were serum levels of lactate dehydrogenase and urea. In extensive disease, however, performance status, levels of serum lactate dehydrogenase and the intensity of therapy turned out to be the best pretherapeutic prognostic factors.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1988

[Methods for the detection of ventricular late potentials. High amplification ECG, signal averaging technic, frequency analysis and intracardiac mapping].

Circumscribed areas of injured myocardium which lead to late ventricular depolarization represent the pathologic-anatomic substrate for reentry mechanisms potentially capable of propagating ventricular tachycardia at the ventricular level. If the myocardial area from which delayed ventricular depolarization and, consequently, late potentials eminate, exceeds a critical minimal size, documentation of such signals can not only be achieved with direct endocardial mapping or catheter mapping but also by means of special high-resolution ECG techniques from the body surface. Since high amplification of the conventional ECG results in registration of noise signals in amplitude of up to 50 microV, late potentials with their amplitudes at the body surface ranging from 5 to a maximum of 20 microV, can only be discriminated after substantial enhancement of the signal-to-noise ratio. The noise arises from no less than three sources: physiologic noise, for example, from muscle activity; electronic noise from amplifiers and background noise of 50 or 60 Hz, respectively. To improve the signal-to-noise ratio, currently three methods are employed: sequential or temporal signal averaging, spatial signal averaging and fast Fourier transformation analysis of the frequency spectrum of the highly-amplified ECG. Temporal signal averaging has the purpose of smoothing randomly-occurring background noise and, at a specified point in time of the ECG cycle, to sum the signal incurred. The effectivity of this technique, however, is subject to certain conditions: the signal to be registered and the background noise must be independent from each other, the noise must be stationary and show normal random distribution, the signal of interest must be periodic and/or coupled with a fixed interval to a point in the ECG cycle which can be used as a trigger. The quality of the averaged signal is dependent on trigger stability. There are three approaches to trigger processing: voltage threshold determination, slope detection and the pattern matching technique, the accuracy, reliability and time-consumption of which increases in the order listed. A trigger stability of +/- 0.5 ms is necessary to detect ventricular late potentials with sufficient sensitivity and without meaningful deformation or attenuation of their form and temporal extent. Intercurrently, a number of commercially-acquirable signal averaging computers have been made available which differ with respect to registration and analysis.(ABSTRACT TRUNCATED AT 400 WORDS)

Atrioventricular Node↗