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Biomedical subjects

C Schmitz

Publications and source records attributed to C Schmitz.

At least 127 records · Page 7Linked to original sources
PubMed1993

In vitro comparison of bileaflet aortic heart valve prostheses. St. Jude Medical, CarboMedics, modified Edwards-Duromedics, and Sorin-Bicarbon valves.

The hydrodynamic performance of four currently used bileaflet heart valve prostheses (St. Jude Medical, CarboMedics, modified Edwards-Duromedics, and Sorin-Bicarbon) with a nominal tissue anulus diameter of 27 mm were measured in the aortic position. All experiments were performed in nonpulsatile flow and in an electrohydraulic, computer-controlled pulse duplicator simulating the left side of the human circulatory system. Testing conditions were set at cardiac outputs of 3.0, 4.5, 6.5, and 8.0 L/min at a constant heart rate of 70 beats/min. The Sorin-Bicarbon valve had the lowest pressure difference with regard to nonpulsatile (mean 5.4 mm Hg at 30 L/min) and pulsatile (mean 2.2 mm Hg at 8 L/min) flow, followed by the St. Jude Medical, CarboMedics, and modified Edwards-Duromedics valves. The leakage volumes under static and pulsatile flow conditions were lowest for the modified Edwards-Duromedics and Sorin-Bicarbon valves. The energy loss in pulsatile flow was lowest for the Sorin-Bicarbon valve, mainly because its systolic, closure, and leakage energy losses were low. Systolic sequential velocity profiles showed the most even flow distribution pattern for the St. Jude Medical and Sorin-Bicarbon valves. These findings correspond with lower overall Reynolds shear stress levels for the St. Jude Medical and the Sorin-Bicarbon valves than for the modified Edwards-Duromedics and CarboMedics valves.

Aortic Valve↗
PubMed1992

[An infected fistula following a peridural catheter].

An infected fistula was observed in a woman (Age: 69 years, weight: 60 kg, height: 159 cm) 14 days after insertion and 8 days after removal of a peridural catheter inserted preoperatively for postoperative analgesia after nephrectomy (carcinoma). Due to haemodynamic problems in the early postoperative period no analgetic or local anaesthetic medication was applied via the peridural catheter. After unsuccessful antibiotic and surgical treatment the women was transferred to the Neurosurgical department five weeks after nephrectomy. Magnetic resonance imaging of the lumbar region showed a fistula (Segment L2/L3) reaching the epidural space but no epidural spreading or epidural abscess. Partial laminectomy L2/L3 was performed and the fistula excised under continuous antibiotic treatment with ofloxacin. Up until 21 months after the operation no recidivation occurred. Exact details of catheter insertion and catheter treatment in the postoperative period are not available; the fact, that no bactericide [9] local anaesthetic agents were applied, might have favoured the occurrence of this infection. Infectious complications have to be taken into consideration for the indication of peridural catheters in the perioperative period.

Aged↗
PubMed1990

Characterization and immunological properties of influenza A virus nucleoprotein (NP): cell-associated NP isolated from infected cells or viral NP expressed by vaccinia recombinant virus do not confer protection.

A nucleoprotein (NP) preparation purified from the chorioallantoic membrane of chicken eggs infected with fowl plague virus (A/FPV/Rostock/34, H7N1) yielded, in addition to the commonly known 56K protein, a 42K component that could not be detected in virus particles. After testing with a series of NP-specific monoclonal antibodies it was found that some reacted with both proteins and others were bound only by the 56K protein. Among both types of NP-specific monoclonal antibodies only a limited number were bound to infected murine cells. Some antibodies bound to cells infected with a given subtype failed to react with the surface of cells infected with a different subtype. Binding was demonstrated by cellular ELISA, radioimmunoassay and immunofluorescence. The results indicate that only restricted antigenic domains of the native NP and perhaps NP fragments are exposed at the surface of infected murine cells. Additionally, the purified NP preparation was used to immunize mice in order to determine the protective capacity of cell-associated NP. In parallel, and as a relevant control, mice were immunized with a vaccinia virus recombinant containing the gene for NP prior to challenge with infectious virus. High levels of monospecific antibodies and a cytotoxic T cell activity was found in mice immunized with purified NP or infected with the vaccinia recombinant after secondary restimulation in vitro. After treatment with specific antibodies the cytotoxic cells were shown to be classical CD8+ cytotoxic T lymphocytes. Despite the elicitation of a humoral and a cellular immune response by the forms of NP employed mice were not protected from influenza virus infection.

Animals↗
PubMed1989

Simplified quantitative determination of phospholipids in amniotic fluid, alveolar lavages and milk using high performance liquid chromatography (HPLC).

A one step HPLC method for the determination of the main phospholipids, phosphatidylglycerol (PG), phosphatidylinositol (PI), phosphatidylethanolamine (PE), phosphatidylcholine (PC), sphingomyelin (SP) and lysolecithin (LL) in amniotic fluid, milk, tracheal secretion, lung lavages, gastric aspirates, infant formulas and some other human and animal media has been developed. Quantitation occurs automatically using computer calculation and lysolecithin as an internal standard. Detection limits are at about 0.2 micrograms/100 ml but may rise to about 0.3 micrograms/100 ml in cases of high fat levels or other interfering compounds. Recovery rates measured in amniotic fluid fluctuate around the 100% level. Time required for a single analysing including a blank run and a calibration standard solution measurement amounts to about two hours. In series analysis 12 samples per day can be examined, while the required time per sample is reduced to 40 minutes. As phospholipids carry an important function in many spheres of medicine, the improvement in specific quantitative determination of these compounds is of great importance.

Amniotic Fluid↗
PubMed1989

[Fluorocytophotometic DNA studies in kidney carcinoma].

DNA measurements in renal cell carcinoma are demonstrating a considerable tumor heterogeneity. Tumor DNA content is one of important prognostic factors. Renal cell carcinomas can be divided into two main groups by single-cell cytophotometry: diploid/near diploid in grade 1 and 2 and mainly aneuploid in grade 3 with variable blocks and peaks. In different tissue samples from the same carcinoma we can found different polymorphism and DNA content.

Adenocarcinoma↗
PubMed1988

Determination of the phospholipid content of human milk, cow's milk and various infant formulas.

The phospholipid (PL) content of human milk, cow's milk, and various infant formulas was determined by recently developed high performance liquid chromatography (6). As the examinations promised, the content of phosphatidylinositol (PI), phosphatidylethanolamine (PE), phosphatidylcholine (PC), and sphingomyelin (SP) was not changed by homogenization and pasteurization of cow's milk. Levels of phosphatidylglycerol (PG) were below the detection limit. Furthermore it has been proved that human milk and cow's milk are more or less identical in PL content. Some of the PL in human milk varies during the course of pregnancy and postpartum. PI, PC, and SP content in the prepartum mammarial secretion lies above the average content of mature human milk after delivery. Before the contractions start, all the PL examined show a more or less considerable decrease. PC drops to 30% of the value at the beginning of the examination six weeks before delivery. PG contents are very low throughout the whole period. Contrary to the others, PC content recovers three weeks after delivery, which may be the result of the endogenous surfactant replacement system. To compare PL content with human milk and cow's milk, 13 different infant formulas have been examined. There are considerable differences to be found in and among adapted milk, partially adapted milk, and special formulas. None of the PL examined could be found in all the infant formulas, where PG content was usually low, except in some Milupa formulas. PE and PI were not to be found in some special formulas. Most of the formulas contain high amounts of SP, in some cases higher than the amount of PC. To a certain extent infant formulas contain a considerably greater amount of other PL concentrations than human milk and cow's milk. In most of the formulas examined the PL content is generally so high, that it can be used as a source of PL for the newborn.

Animals↗
PubMed1987

[Uninodular bronchiolo-alveolar cancer. Apropos of 5 cases with a prolonged course].

Five cases of uninodular bronchioloalveolar cell (BAC) carcinoma are reported. These 5 cases were characterized by the protracted course of the disease: 14.5 and 11.5 years respectively in the 2 patients who died; 7.5, 12 and 12.5 years respectively in the 3 patients who are still alive. Prior to being diagnosed at excision, the tumours had been followed up for an unusual 2 to 10 years period, with phases of radiological stability and phases of very slow growth. This very slow course is exceptional in lung cancer. It differs not only from the course of diffuse BAC carcinoma, but also from the habitual course of uninodular BAC carcinoma and from that of peripheral adenocarcinoma. Similar cases could be found in the literature, and a comparative study has been conducted between these slow-course carcinomas and normal-course carcinomas. Whatever their outcome, slow-course carcinomas are asymptomatic tumours which present at radiography of the chest as a peripheral round or oval opacity devoid of pathognomonic features. The post-operative prognosis of slow-course tumours seems to be more favourable than that of the other lung cancers. At histology, carcinomas with a protracted course usually show a pattern similar to that of lesions called by some authors "benign adenomatosis"; however, some of these tumours exhibit fairly distinct signs of malignancy, and electron microscopic images also are far from being uniform.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed1983

Ovarian torsion cyst presenting as a wandering tumor in a newborn: antenatal diagnosis and post natal assessment.

A case of an in-utero torsion ovarian cyst is reported. The diagnosis was made antenatally and the 4-cm cystic mass was followed by US from birth until the age of 3 months. Surgery was delayed until the baby reached a satisfactory weight. In the meanwhile, the follow-up studies showed the mass to wander in the abdomen. Surgery revealed an ovarian cyst. Ovarian torsion cysts should be considered in the differential diagnosis of wandering tumors.

Abdominal Neoplasms↗
PubMed1975

[Dependence on age of the effects of catecholamines in man I. Effect of noradrenaline, adrenaline and isoprenaline on blood pressure and heart rate].

In 2- to 3-year-old, 18- to 34-year-old as well as 57- to 75-year-old persons the effect of a one hour's permanent infusion of noradrenalin (0.0625 mug/min kg), adrenalin (0.025 mug/min kg) and isoprenalin (0.0142 mug/min kg) on blood pressure and hear rate is investigated. In a concerning age uniform dosage/body weight isoprenalin and adrenalin increase the heart rate of the older organism on a larger scale than in the younger. The increased sensitiveness of the heart of old persons to beta-adrenergics is to be taken in consideration in therapeutic use with regard to cardiac side effects. In juvenile adults the systolic blood pressure is more increased by isoprenalin as well as the diastolic blood pressure by noradrenalin than in older persons. The concerning age different cardiovascular effects of the investigated adrenergics in man are discussed in connection with findings of animal experiments with regard to aging in the sensitiveness of adrenergic receptors.

Adolescent↗
PubMedDate not supplied

[Extracorporeal shock waves induce ventral-periosteal new bone formation out of the focus zone--results of an in-vivo animal trial].

AIM: It is known that high-energy extracorporeal shock waves, focussed to the intact distal rabbit femur, induce periosteal new bone formation within the focus zone. This study was done to investigate whether there is additionally new bone formation outside of the focus zone, i. e., in the proximal femur, 10 days after shock wave application to the distal rabbit femur. METHOD: 18 adult Chinchilla-Bastard rabbits were randomly divided into three groups (A, B, C; each n = 6). One distal femur of each animal was focussed for shock wave application with different positive energy flux densities (A 1.2 mJ/mm (2), B 0.9 mJ/mm (2), C sham treatment). Only the proximal femur outside the shock wave focus was investigated. Here periosteal new bone formation was evaluated by fluorescent labelling. The maximum thickness was measured by means of computer-assisted image analysis. RESULTS: Maximum ventral-periosteal new bone formation outside the shock wave focus was significantly increased in group A compared to group B (p = 0.007) or group C (p = 0.001). In contrast, the maximum ventral-periosteal new bone formation outside the shock wave focus demonstrated no statistically significant difference in group B compared to group C (p = 1.0). CONCLUSION: Depending from the amount of positive energy flux density applied to distal rabbit femur a significantly increased ventral-periosteal new bone formation results in the proximal rabbit femur outside the shock wave focus.

Animals↗
PubMedDate not supplied

[Mineral analysis of roentgenologically defined calcifications in patients with chronic calcifying tendinitis of the rotator cuff].

AIM: Extracorporeal shockwave application (ESWA) is in clinical use to promote disintegration of symptomatic calcifications of the rotator cuff of the shoulder. However, disintegration of roentgenologically comparable calcifications of the rotator cuff is not always successfull. It is known from urologic stone lithotripsy that the susceptibility for disintegration of stone-like concrements depends on their mineral content. Therefore, in the present investigation the relative contents of calcium and phosphorus in rotator cuff calcifications were determined. METHOD: 39 surgically removed rotator cuff calcifications were analyzed by means of atomic emission spectrometry. RESULTS: The relative content of calcium of the rotator cuff calcifications was found to be 22.3 % +/- 5.7 % (mean +/- SD; 6.8 % - 32.4 %), that of phosphorus as 10.5 % +/- 2.4 % (2.7 % - 14.4 %). The data neither depend on the gender of the patients nor on their age at the time point of surgical removal of the rotator cuff calcifications. CONCLUSION: Roentgenologically comparable calcifications of the rotator cuff demonstrated distinct individual differences concerning the relative contents of calcium and phosphorus. The present results may serve as the first indication that the susceptibility of rotator cuff calcifications for disintegration may depend on their relative contents of calcium and phosphorus.

Adult↗
PubMedDate not supplied

[Detection of bone fragments in pulmonary vessels following extracorporeal shock wave application to the distal femur in an in-vivo animal model].

AIM: In urology, single cases of lethal pulmonary embolism following extracorporeal shock wave application to renal concrements have been reported. Therefore, lungs of rabbits were histopathologically investigated following extracorporeal shock wave application to the femur. METHOD: In 8 mature Chinchilla-Bastard rabbits, shock wave application to one distal femur was performed with energy flux density of 0.9 mJ/mm2. In another 6 rabbits, sham-treatment (0 mJ/mm2) to one distal femur was performed. 6 weeks later, the animals were sacrificed and their lungs were blindly investigated by an independent pathologist. RESULTS: In 7 out of the 8 treated animals (0.9 mJ/mm2) but in none of the sham-treated controls, patchy discolorations of the surface of the lung were observed. Furthermore, in 6 out of the 8 treated animals but in none of the sham-treated controls, bony fragments with signs of resorption were observed in lung vessels. CONCLUSION: Application of extracorporeal shock waves with energy flux densities higher than 0.9 mJ/mm2 has been recommended in the literature for the treatment of aseptic non-unions. In this procedure, the possibility of the occurrence of bone fragments in the lung with the potential risk of pulmonary embolism should be regarded.

Animals↗
PubMedDate not supplied

[Lung maturation during artificial placentation and mechanical lung distension].

An new method of lung maturation during artificial placentation was evaluated during a series of 15 animal experiments in premature lambs (gestational age 125-132 days). Perfusion circuit with interposition of a membrane lung was connected with the umbilical vessels. Extracorporeal CO2-removal (ECCO2-R) and apneic oxygenation were provided during lung distension. The ultramicroscopic pattern approved a maturation of the lung during the procedure showing development of lamellar bodies and surfactant secretion into the alveolar space. The biochemical analysis of the tracheal fluid showed a significant increase of both PC and PG concentrations (3.225 +/- 1.112 mg/100g to 24.228 +/- 3.36 mg/100 g respectively 0.249 +/- 0.11 mg/100 g of 0.622 +/- 0.09 mg/100 g. The biophysical function of the lung was also improved as was shown by a significant increase of the statistical compliance. We conclude that artificial placentation and lung distension might be a new mode of prophylaxis for respiratory distress syndrome in critically immature babies.

Animals↗
PubMedDate not supplied

Influence of severe burn injury on the expression of RM 3/1 and HLA-DR antigens in human blood monocytes.

The effect of severe burns on the expression of the glucocorticoid-inducible RM 3/1 and HLA-DR antigens in blood monocytes was studied in patients with less than or more than 50% total body surface area (TBSA) burned. All patients showed a strong increase in the portion of RM 3/1+ monocytes within 1 day after injury. In patients with more than 50% TBSA, RM 3/1+ cells decreased after 2 days; in those with less than 50% TBSA, cells decreased after 3 days HLA-DR+ monocytes decreased within 4 days in both groups. In patients with less than 50% TBSA, HLA-DR+ monocytes slowly increased thereafter to basic levels. In patients with more than 50% TBSA, HLA-DR+ monocytes further decreased, then slowly increased, however, did not reach basic levels. This long-lasting decrease was evidence in the nonsurvivors. These results show that severe burns differently affect monocyte antigens. The induction of the anti-inflammatory subtype RM 3/1 and the decrease of the immunoregulatory HLA-DR antigens may contribute to the immunosuppression observed after burn injury.

Adolescent↗