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M Lippert

Publications and source records attributed to M Lippert.

14 recordsLinked to original sources
PubMed2002

Relative ventricular volume measurements by intracardiac impedance.

The purpose of this study was to investigate whether changes of the right ventricular end-diastolic and end-systolic volumes can be detected by the DC-coupled electrical intracardiac impedance signal. Measurements were conducted in 13 patients with an implanted or external pacemaker, testing various measurement configurations. Volume changes were induced by incremental overpacing and by postural changes. The pulse contour systolic integral from the peripheral blood pressure was used as a marker of stroke volume changes. The results show, that DC-coupled impedance can detect volume changes of the right ventricle. The quadrupolar impedance measurement configurations offer better amplitude resolution, but the tripolar and intraventricular bipolar configurations are better hemodynamic markers.

Aged↗
PubMed2000

Men's attitudes regarding genetic testing for hereditary prostate cancer risk.

OBJECTIVES: Little is known about the attitudes of men unselected for a family history for prostate cancer concerning genetic testing for prostate cancer risk or genetic testing for inherited cancer predisposition. To explore this, we examined the interest in molecular testing for hereditary prostate cancer (HPC) predisposition among a self-selected cohort of 342 men presenting for prostate cancer screening. METHODS: Participants were surveyed concerning their attitudes about DNA testing for HPC predisposition and knowledge of prostate cancer-associated risk factors, including heredity. RESULTS: Of the participants completing the survey, 92% expressed interest in learning about DNA testing, and 89% stated that they would undergo DNA analysis for HPC predisposition, if available. Twenty-eight percent of respondents failed to demonstrate an adequate understanding of the concept of "inherited tendency." The demonstrated level of understanding of this concept did not differ by the respondent's family history, although it varied by race. An interest in learning about or undergoing testing did not vary by race, family history, or demonstrated understanding of the concept of inherited risk. CONCLUSIONS: Among men presenting for routine prostate cancer screening, interest in learning about testing for HPC predisposition and in having such testing performed may be high. The data also provide evidence that, in a population of men unselected for family history, interest in molecular testing for this common, male-specific cancer may parallel the high interest level demonstrated among women in DNA testing for inherited breast and ovarian cancer risk.

Adult↗
PubMed2000

Closed-loop stimulation using intracardiac impedance as a sensor principle: correlation of right ventricular dP/dtmax and intracardiac impedance during dobutamine stress test.

Changes of the unipolar right ventricular impedance during the cardiac cycle are related to the changing content of blood (low impedance) and tissue (high impedance) around the tip of the pacing electrode. During myocardial contraction, the impedance continuously increases reaching its maximum in late systole. This impedance increase is thought to correlate with right ventricular contractility, and thus, with the inotropic state of the heart. In the new Inos2 DDDR pacemaker, integrated information from the changing ventricular impedance (VIMP) is used for closed-loop regulation of the rate response. The aim of this study was to analyze the effect of increasing dobutamine challenge on RV contractility and the measured impedance signals. In 12 patients (10 men, 68 +/- 12 years) undergoing implantation of an Inos2 DDDR pacemaker (Biotronik), a right ventricular pigtail catheter was inserted for continuous measurements of RV-dP/dtmax and simultaneous VIMP signals during intrinsic and ventricular paced rhythm. Then, a stress test with a stepwise increase of intravenous dobutamine (5-20 micrograms/kg per min) was performed. To assess the relationship between RV contractility and measured sensor signals, normalized values of dP/dtmax and VIMP were compared by linear regression. There was a strong and highly significant correlation between dP/dtmax and VIMP for ventricular paced (r2 = 0.93) and intrinsic rhythm (r2 = 0.92), although the morphologies of the original impedance curves differed quite substantially between paced and intrinsic rhythm in the same patient. Furthermore, VIMP correlated well with sinus rate (r2 = 0.82), although there were at least four patients with documented chronotropic incompetence. We conclude, that for intrinsic and ventricular paced rhythms sensor signals derived from right ventricular unipolar impedance curves closely correlate with dP/dtmax, and thus, with a surrogate of right ventricular contractility during dobutamine stress testing. Our results suggest that "inotropy-sensing" via measurement of intracardiac impedance is highly accurate and seems to be a promising sensor principle for physiological rate adaptation in a closed-loop pacing system.

Aged↗
PubMed1998

Memory effects in the action of ozone on conifers.

Conifers are known to possess relative ozone tolerance in short-term experiments. A scenario for ozone damage of conifers is now derived from the first exposure experiments in which both the initial biochemical response phase and delayed visible symptom development were studied. A number of early biochemical ozone responses could be detected in Norway spruce (Picea abies [L.] Karst.) and Scots pine (Pinus sylvestris L.). The stress metabolite catechin persisted over several months. In the year following ozone treatment of spruce, decreases in pigment content and photosynthetic capacity, as well as development of visible symptoms (chlorosis, banding), were determined in the needle age classes previously exposed to an accumulated hourly ozone dose above 40 ppb (AOT40) of >/=60-80 ppm small middle doth. The visible symptoms developed during spring emergence of the new flush. In the case of Scots pine, an ozone dose (AOT40) of >/=30 ppm small middle doth caused the premature shedding of needles 9 months after treatment. The delayed symptoms of both spruce and pine occurred during known phases of endogenous stress. The symptoms appeared to reflect an ozone "memory" imprinted by the induced early stress reactions. Ambient AOT40 ozone doses in Central Europe are in the range 4 and 50 ppm small middle doth per growing season. Ozone is proposed to potentially damage conifers through memory effects ("abiotic" pathway) or through predisposition for pathogen attack ("biotic" pathway).

Catechin↗
PubMed1997

Additional clinical and cytogenetic findings associated with Rett syndrome.

An analysis of all aphidicolin-inducible breakpoints has been carried out in PHA stimulated T-lymphocytes of five patients with classical Rett syndrome, their mothers and a group of age matched controls. Observed breakpoints were divided into two groups: common, rare, and those recorded by others but not assigned as fragile sites by CCM92 and a group of non-specified breakpoints recurrently found in our ongoing study of fragile sites. In addition cooccurrence of trisomy X in one patient and de novo pericentromeric inversion on chromosome 2 in another Rett syndrome patient are reported. The co-occurrence with the Tourette syndrome in two of our families, and the fact that both Rett and Tourette syndrome are associated with movement disorders, possible dopaminergic hypersensitivity and increased chromosomal fragility in subsets of fragile sites, may suggest a possible avenue for further research. The cytogenetic findings indicate that both X-linked and autosomal regulatory region(s) may be part of a complex genetic alteration in association with Rett syndrome.

Aphidicolin↗
PubMed1995

[Not Available].

Explore the source record for details and available documents.

Czech Republic↗
PubMed1992

Benign prostatic hyperplasia: appearance on magnetic resonance imaging.

Benign prostatic hyperplasia (BPH) has a variable appearance on magnetic resonance imaging (MRI). This study reviews and categorizes the MRI findings of this entity in a sample of 26 men. Cases where atypical or suspicious changes are incidental findings should be reported to the urologist for further investigation. In addition, familiarity with both the appearance of the normal prostate and the changes caused by BPH is necessary when staging patients with known prostate cancer.

Humans↗
PubMed1989

Intragastric bile acid concentrations in critically ill, artificially ventilated patients.

Bile acids have experimentally been found to damage the gastric mucosa and, thus, may be involved in stress lesion pathogenesis. We therefore measured intragastric bile acid concentrations in 26 critically ill, artificially ventilated patients. The control group consisted of eight healthy volunteers, whose treatment was similar to that of the patients with respect to bed rest, enteral feeding, and administration of H2-blockers. Gastric contents were aspirated via a gastric tube every hour for 24 h. Patients had higher intragastric bile acid concentrations than healthy controls, whether fasting [median 1.3 mmol/L (range 0.7-2.5) versus 0.3 (0.2-0.5) (p less than 0.05)] or fed via a gastric tube [1.3 (0.4-4.0) versus 0.4 (0.2-0.7) (p less than 0.05)]. Physiotherapy, nursing, and drugs (opiates, benzodiazepines, dopamine, pirenzepine, and metoclopramide) had no detectable influence on intragastric bile acid concentrations and pH in patients. We conclude that patients at risk to develop stress lesions have largely increased gastric bile acid concentrations that probably are due to increased duodenogastric reflux. This might be relevant for stress lesion pathogenesis.

Adult↗
PubMed1983

Detection of cell surface antigen in cancer of renal pelvis and ureter.

Thirty-five patients with transitional cell carcinoma of the renal pelvis or ureter of all stages and grades were studied for presence or absence of ABO(H) antigens utilizing an improved technique for staining and preserving the slides. Seventy per cent of the grade I tumors retained their antigens. Patients with antigen present had a longer duration of disease-free interval. Specific red cell adherence (SRCA) may predict the clinical course of patients with low-stage, low-grade transitional cell carcinomas and may be helpful in selecting patients for optimal therapy.

ABO Blood-Group System↗
PubMed1981

Role of lactate dehydrogenase isoenzymes in testicular cancer.

Changes in the serum levels of lactate dehydrogenase have been noted to reflect growth and/or regression in many patients with testicular tumors, but they were nonspecific. However, elevation of the first of the LDH isoenzymes (LD-1) has been found specific to testicular cancer among all neoplasms. In this prospective preliminary report of 19 testicular cancer patients serum LD-1 was found to be normal in 4 patients with no tumor present. Therefore, there were no false positive findings. Of 6 patients with microscopic disease, LD-1 level was normal. Of 9 patients with gross disease, 5 had elevated serum LD-1 and 4 had normal LD-1. Of 4 patients with seminoma, 3 had elevated LD-1 while all 4 patients had no other elevated markers. It appears that elevation of serum LD-1 provides a marker for seminoma and a marker with some specificity for testicular cancer.

Clinical Enzyme Tests↗
PubMed1980

The value of whole lung tomography in the early detection of metastatic disease in patients with renal cell carcinoma and testicular tumors.

The value of whole lung tomography was compared to chest x-rays in patients with renal cell carcinoma and germ cell testicular tumors. We studied 83 patients with testicular tumors and 34 with renal cell carcinoma. At least 1 metastatic lesion was present on whole lung tomography in 11 of 64 patients (17 per cent) with testicular tumors and 2 of 21 (10 per cent) with renal cell carcinoma who had negative chest x-rays. Of the patients with a solitary lesion on the chest x-ray 3 of 10 (30 per cent) with testicular tumor and 5 of 11 (45 per cent) with renal cell carcinoma had multiple metastatic lesions on whole lung tomograms. Falsely positive chest x-rays were noted in 6 of 15 patients (40 per cent) with renal cell carcinoma and 6 of 16 (37 per cent) with testis tumor. These falsely positive results were caused by overlapping shadows, vessels or granulomas.

Adenocarcinoma↗