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Biomedical subjects

J Stadler

Publications and source records attributed to J Stadler.

At least 145 records · Page 8Linked to original sources
PubMed1978

Structure and biochemical composition of desmosomes and tonofilaments isolated from calf muzzle epidermis.

Complexes of plasma membrane segments with desmosomes and attached tonofilaments were separated from the stratum spinosum cells of calf muzzle by means of moderately alkaline buffers of low ionic strength and mechanical homogenization. These structures were further fractionated by the use of various treatments including sonication, sucrose gradient centrifugation, and extraction with buffers containing high concentrations of salt, urea, citric acid, or detergents. Subfractions enriched in desmosome-tonofilament-complexes and tonofilament fragments were studied in detail. The desmosome structures such as the midline, the trilaminar membrane profile, and the desmosomal plaque appeared well preserved and were notably resistant to the various treatments employed. Fractions containing desmosome-tonofilament complexes were invariably dominated by the nonmembranous proteins of the tonofilaments which appeared as five major polypeptide bands (apparent molecular weights: 48,000; 51,000; 58,000; 60,000; 68,000) present in molar ratios of approx. 2:1:1:2:2. Four of these polypeptide bands showed electrophoretic mobilities similar to those of prekeratin polypeptides from bovine hoof. However, the largest polypeptide (68,000 mol wt) migrated significantly less in polyacrylamide gels than the largest component of the hoof prekeratin (approximately 63,000 mol wt). In addition, a series of minor bands, including carbohydrate-containing proteins, were identified and concluded to represent constituents of the desmosomal membrane. The analysis of protein-bound carbohydrates (total 270 microgram/mg phospholipid in desmosome-enriched subfractions) showed the presence of relatively high amounts of glucosamine, mannose, galactose, and sialic acids. These data as well as the lipid composition (e.g., high ratio of cholesterol to phospholipids, relatively high contents of sphingomyelin and gangliosides, and fatty acid pattern) indicate that the desmosomal membrane is complex in protein and lipid composition and has a typical plasma membrane character. The similarity of the desmosome-associated tonofilaments to prekeratin filaments and other forms of intermediate-sized filaments is discussed.

Animals↗
PubMed1978

[Results of surgical treatment of acute knee joint injuries after winter sport accidents].

From 1974 to 1976 140 patients with knee joint injuries required immediate surgical treatment. 119 of these patients have been reexamined 1 to 3 years after operation, 83 by the authors. Clinical findings, indication for operation, operative procedures and the criteria for analysis of the late results are discussed. Good and satisfactory results were found in 96% of the cases. The results after reconstruction of the medial collateral ligament are excellent, 39 of 41 operatively treated patients showing a good result. After combined reconstruction of collateral and cruciate ligaments in 2/3 of the cases good results were obtained. Complications occurred in two cases requiring further surgery. The importance of intensive physiotherapeutical training until full rehabilitation of the injured joint was stressed.

Athletic Injuries↗
PubMed1978

[On secondary operations following submucous septum resection (author's transl)].

The submucous resection of septum by Killian is not appropriate as a primary correcting treatment, especially in case of traumatical septum deformities. Due do the loss of cartilage often form and function of the nose deteriorates in a typical way. These complaints demand an operative correction under complicated circumstances. Based on the patient clietele of the Univ.-HNO-Klinik Erlangen it is demonstrated how secondary operations with the special technique of displacement of the remaining cartilage a satisfying result finally can be achieved.

Congenital Abnormalities↗
PubMed1977

Increased polyethylene glycol-mediated fusion competence in mitotic cells of a mouse lymphoid cell line.

Spontaneous mitotic cells of the mouse leukemic cell line GF7 are preferentially included in cell fusion products after treatment with polyethylene glycol (PEG). This implies a unique configuration of the natural mitotic membrane which is particularly vulnerable to induction of fusion by PEG. Colcemid-arrested GF7 mitotic cells, however, are excluded from PEG-induced cell fusion products, suggesting that colcemid reverses the membrane configuration which is susceptible to the action of PEG. When Sendai virus is used as the fusogenic agent, both colcemid-arrested and spontaneous mitotic cells are selectively fused. There must, therefore, be an essential membrane-fusogen reaction which is characteristically different for each of these agents.

Cell Fusion↗
PubMed1977

[Antibiotic prevention using cephalothin].

A single intravenous dose of Cephalotine, given at the start of operations, significantly reduces the incidence of postoperative wound infections. The concentration of Cephalotine was maintained throughout operation. The occurrence of other infections was also reduced. The results of this study imply that operations on patients with higher infectious risk should be accompanied by antibiotic prophylaxis.

Adolescent↗
PubMed1976

Characterization of nuclear membranes and endoplasmic reticulum isolated from plant tissue.

Nuclei, nuclear membranes and rough endoplasmic reticulum (rER) were isolated from onion root tips and stems. Structural preservation and purity of the fractions was determined by electron microscopic and biochemical methods. Gross compositional data (protein, phospholipid, nonpolar lipids, sterols, RNA, DNA), phospholipid and fatty acid patterns, enzyme activities (ATPases, ADPase, IDPase, glucose-6-phosphatase, 5'-nucleotidase, acid phosphatase, and NADH- and NADPH-cytochrome C reductases), and cytochrome contents were determined. A stable, high salt-resistant attachment of some DNA with the nuclear membrane was observed as well as the association of some RNA with high salt-treated nuclear and rER membranes. The phospholipid pattern was identical for both nuclear and rER membranes and showed a predominance of lecithin (about 60%) and phosphatidyl ethanolamine (20-24%). Special care was necessary to minimize lipid degradation by phospholipases during isolations. Nonpolar lipids, mostly sterols and triglycerides, accounted for 35-45% of the membrane lipids. Sterol contents were relatively high in both membrane fractions (molar ratios of sterols to phospholipids ranged from 0.12 to 0.43). Sitosterol accounted for about 80% of the total sterols. Palmitic, oleic, and linoleic acids were the most prevalent acids in membrane-bound lipids as well as in storage lipids and occurred in similar proportions in phospholipids, triglycerides and free fatty acids of the membrane. About 80% of the fatty acids in membrane phospholipids and triglycerides were unsaturated. A cytochrome of the b5 type was characterized in these membranes, but P-450-like cytochromes could not be detected. Both NADH and NADPH-cytochrome c reductases were found in nuclear and rER membranes and appeared to be enriched in rER membranes. Among the phosphatases, Mg2+-ATPase and, to lesser extents, ADPase, IDPase and acid phosphatase activities occurred in the fractions, but significant amounts of monovalent ion-stimulated ATPase, 5'-nucleotidase and glucose-6-phosphatase activities did not. The results obtained emphasize that the close biochemical similarities noted between rER and nuclear membranes of animal cells extend to these fractions from plant cells.

Acid Phosphatase↗
PubMed1976

Experimental disintegration of the nuclear envelope. Evidence for pore-connecting fibrils.

The disintegration of the nuclear envelope has been examined in nuclei and nuclear envelopes isolated from amphibian oocytes from amphibian oocytes and rat liver tissue, using different electron microscope techniques (ultrathin sections and negatively or positively stained spread preparations). Various treatments were studied, including disruption by surface tension forces, very low salt concentrations, and nonionic detergents such as Triton C-100 and Nonidet P-40. The highest local stability of the cylinders of nonmembranous pore complex material is emphasized. As progressive disintegration occurred in the membrane regions, a network of fibrils became apparent which interconnects the pore complexes and is distinguished from the pore complex-associated about 15-20 nm thick, located at the level of the inner nuclear membrane, which is recognized in thin sections to bridge the interpore distances. With all disintegraiton treatments a somewhat higher susceptibility of the outer nuclear membrane is notable, but a selective removal does not take place. Final stages of disintegration are generally characterized by the absence of identifiable, membrane-like structures. Analysis of detergent-treated nuclei and nuclear membrane fractions shows almost complete absence of lipid components but retention bo significant amount of glycoproteins with a typical endomembrane-type carbohydrate pattern. Various alternative interpretations of these observations are discussed. From the present observations and those of Aaronson and Blobel (1,2), we favor the notion that threadlike intrinsic membrane components are stabilized by their attachment to the pore complexes, and perhaps also to peripheral nuclear structures,and constitute a detergent-resistant, interpore skeleton meshwork.

Animals↗
PubMed1976

Hemodynamic correlates of the normal aortic valve echogram. A study of sound, flow, and motion.

The aortic valve echogram was recorded in open chest dogs simultaneously with aortic flow, acceleration of flow, aortic and left ventricular pressures, and intracardiac phonocardiograms. Comparison of echographic with hemodynamic data showed the following: The aortic valve started its opening with the onset of flow, at the same point that left ventricular pressure exceeded aortic pressure. Complete valve opening preceded peak aortic flow by an average of 43 msec and the cusps started to move toward closure while flow was still accelerating. Final closure of the valve was achieved at the time of zero flow and preceded the aortic second sound by 4-10 msec. The echographically determined "valve orifice area" correlated well with aortic stroke volume (r = 0.94). The intensity of the aortic first sound was related to peak acceleration of aortic flow. The intensity of the second sound was not related to the amplitude of cusp motion but correlated well with the aortic pressure at the time of closure and with peak flow deceleration.

Animals↗
PubMed1976

[Treatment of pathologic fractures].

Eight pathologic fractures of benign and 52 of malignant origin are reported. Open reduction and rigid internal fixation should be performed to give the patient the use of his affected limb as soon as this can be accomplished. Treatment consists of internal fixation in lesions of the shaft and prosthetic replacement in the case of lesions near joints. Only very rarely a primary amputation must be performed. Malignant fractures are most frequently caused by metastases from breast cancers. The treatment will at least make nursing easier, and three-quarters of these patients can be mobilized. The combination of surgical treatment and radiotherapy is discussed. In spite of this approach the average time of survival of 14 months is short because a pathological fracture due to a malignant tumor is a late symptom of the disease.

Amputation, Surgical↗
PubMed1975

[Surgically treated malleolar fractures--results after 3 to 4 years under special consideration of the talus profile (author's transl)].

An account is given of 216 cases of fracture of the ankle joint treated with the AO method. 167 patients with 168 fractures could be controlled personally 3-4 years after operative treatment. In 90% we found a good or satisfactory result. The result depends on the anatomical reconstruction of the congruity of the joint and the primary defect of the cartilage. The arthrosis seen in X-rays must not show a bad clinical function. Contrary to the experimental results the form of the talus is not important to the clinical course.

Ankle Joint↗
PubMed1975

A study of the dynamic relations between the mitral valve echogram and phasic mitral flow.

Echocardiographically recorded mitral valve motion was compared with phasic transmitral flow in 17 open chest dogs. The normal mitral valve opening started with the onset of mitral flow and reached its full excursion while flow was still accelerating. Complete valve opening occurred .044 sec (plus or minus .002 sem) before peak flow, during which time an average of 17.6 percent of total mitral filling volume had passed through the valve. In contrast to the opening movement, the closing motion of the anterior mitral valve cusp lagged behind the deceleration of mitral flow. The E-F phase of the mitral valve echogram started while mitral flow was still increasing and resulted from a combined posterior motion of the cusp and the ring. The E-F slope of the normal valve was found to decrease with reduced cardiac output. The amplitude of the anterior cusp excursion did not reflect the amount of mitral flow. Prolonged P-R interval may induce a mid-diastolic reversal of mitral flow which, in turn, may be accompanied by partial or complete valve closure, occurring before the onset of ventricular contraction. Such premature closure of the mitral valve may be accompanied by a certain amount of regurgitant flow.

Animals↗