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Biomedical subjects

H Weiss

Publications and source records attributed to H Weiss.

At least 307 records · Page 17Linked to original sources
PubMed1983

[Massive pulmonary embolism: case report of successful embolectomy with transatrial vena cava blockade].

Massive pulmonary embolism occurred in a 42-year-old man 7 days after repair of a torn patellar ligament. Because of progressive deterioration in spite of full heparinization and supportive measures, and more than 60% occlusion of the pulmonary vascular bed on angiogram, partial cardiopulmonary bypass was instituted under local anesthesia by femoral artery and vein canulation. After improvement of hemodynamics and tissue oxygenation, general anesthesia was induced, the patient intubated and a longitudinal sternotomy carried out. The superior vena cava was canulated, the inferior vena cava occluded with a tourniquet and the pulmonary artery incised during temporary aortic occlusion. The left main pulmonary artery and its branches were nearly completely occluded, in addition, a large embolus was expressed into the right pulmonary artery by massaging the right lung. Finally, transatrial infrarenal caval interruption with a Mobin-Uddin umbrella filter was carried out. After 48 hours of mechanical ventilation, the patient was extubated; he made an essentially uneventful recovery.

Adult↗
PubMed1983

Transient kinetic studies of Neurospora crassa cytochrome c oxidase.

The reaction of Neurospora crassa cytochrome c oxidase with CO was studied by flash-photolysis and rapid-mixing experiments, leading to the determination of the association and dissociation rate constants (7 X 10(4) M-1 X s-1 and 0.02s-1 respectively). Pre-steady-state kinetic investigations of the catalytic properties of the enzyme showed that under proper conditions Neurospora cytochrome c oxidase can be 'pulsed', i.e. activated, like the mammalian enzyme. The 'pulsed' species is spectroscopically different from the 'resting' one, and the decay into the 'resting' state is fast (t1/2 approx. 3 min).

Carbon Monoxide↗
PubMed1983

Low-resolution structural studies of mitochondrial ubiquinol:cytochrome c reductase in detergent solutions by neutron scattering.

Mitochondrial ubiquinol:cytochrome c reductase (Mr approximately 600,000) was cleaved into a complex (Mr approximately 280,000) of the subunits III (cytochrome b), IV (cytochrome c1) and VI to IX, a complex (Mr approximately 300,000) of the subunits I and II, and the single subunit V (iron-sulphur subunit, Mr approximately 25,000). Neutron scattering was applied to the whole enzyme, the cytochrome bc1 complex, both in hydrogenated and deuterated alkyl (phenyl) polyoxyethylene detergents, and the complex of subunits I and II in detergent-free solution. The neutron parameters were compared with the structures of the enzyme and the cytochrome bc1 complex previously determined by electron microscopy. Using the method of hard spheres, comparison of the calculated and experimental radius of gyration implies that the length of the enzyme across the bilayer or the detergent micelle is between 150 and 175 A and of the cytochrome bc1 complex between 90 and 115 A. The subunit topography was confirmed. The cleavage plane between the cytochrome bc1 complex and the complex of subunits I and II lies at the centre of the enzyme and runs parallel to the membrane just outside the bilayer. The detergent uniformly surrounds the protein as a belt, which is displaced by 30 to 40 A from the protein centre of the enzyme and by about 20 A from the protein centre of the cytochrome bc1 complex. The low protein matchpoint of the whole enzyme as compared to the subunit complexes is accounted for in terms of the non-exchange of about 30 to 60% of the exchangeable protons within the intact enzyme. Polar residues are, on average, at the protein surface and non-polar residues and polar residues with non-exchanged protons are buried within the enzyme.

Amino Acids↗
PubMed1983

Structural studies of cytochrome reductase. Subunit topography determined by electron microscopy of membrane crystals of a subcomplex.

Ubiquinol: cytochrome c reductase was isolated from Neurospora mitochondria as a protein-detergent complex and dissociated by mild salt treatment. Three parts were obtained and characterized. Firstly, a complex containing the subunits III (cytochrome b), IV (cytochrome c1), VI, VII, VIII and IX; secondly, a complex containing the subunits I and II; and thirdly, the single subunit V (iron-sulphur subunit). Membrane crystals were prepared from the cytochrome bc1 subunit complex and by combining tilted electron microscopic views of the crystals, a low-resolution three-dimensional structure was calculated. This structure was compared to that of the whole cytochrome reductase (previously determined by electron microscopy of membrane crystals). Protein density absent from the structure of the subunit complex was then attributed to the missing subunits according to their size and shape and their association with the phospholipid bilayer.

Crystallization↗
PubMed1983

Structural studies of cytochrome reductase. Improved membrane crystals of the enzyme complex and crystallization of a subcomplex.

Membrane crystals of mitochondrial ubiquinol: cytochrome c reductase of improved size and long-range order and of the cytochrome bc1 subcomplex have been obtained by a dialysis method. The enzyme--Triton X-100 complex was mixed with Triton phospholipid micelles and the Triton slowly removed by dialysis for 48 hours at pH 5.5 at room temperature or above. The effect of varying the pH and temperature on the shape, size and order of the crystals is described.

Crystallization↗
PubMed1983

Herpes zoster ophthalmicus and delayed contralateral hemiparesis caused by cerebral angiitis: diagnosis and management approaches.

Four patients with herpes zoster ophthalmicus and delayed contralateral hemiparesis are described, and their findings are compared with those in patients previously reported in the English language literature. The current patients evidenced multifocal ipsilateral cerebral angiitis by angiography and multifocal infarcts in the distribution of the ipsilateral middle cerebral artery by computed tomographic scanning. Cerebrospinal fluid showed mononuclear pleocytosis, positive oligoclonal bands, and an elevated immunoglobulin G index. Two patients were treated with corticosteroids and acyclovir, and 1 with corticosteroids alone, all without apparent response. Necrotizing angiitis ipsilateral to the herpes zoster ophthalmicus was demonstrated postmortem in 1 patient with multifocal cerebral infarction and progressive leukoencephalopathy. Neither herpes varicella zoster immunocytochemical reactivity nor viral inclusions were seen. The leukoencephalopathy associated with herpes varicella zoster either may be caused by cerebral angiitis or, as previously reported, may be a temporally remote manifestation of persistent herpes varicella zoster infection. The cerebral angiitis associated with herpes varicella zoster is histologically similar to granulomatous angiitis, and both may be related to herpes varicella zoster infection of the cerebral vasculature.

Acyclovir↗
PubMed1983

Difference in chromatin sensitivity to heparin of chronic atrophic gastritis, of carcinoma-free and carcinoma-bearing stomach in comparison with normal gastric mucosa and gastric carcinoma as revealed by flow cytometry.

DNA distribution patterns from gastric mucosal cells corresponding to four groups defined by histological examination were measured by flow cytometry before and after treatment with heparin, a polyanion. Group I comprised normal gastric mucosal cells; group II, chronic atrophic gastric mucosal cells originating from a carcinoma free stomach; group III, chronic atrophic gastric mucosal cells originating from a carcinoma bearing stomach; and group IV, malignant gastric mucosal cells. The heparin concentrations used were 1.25, 1.5, and 5 U/ml cell suspension. Heparin caused increases in fluorescence intensity and in coefficients of variation, which are interpreted as a reflection of alterations in chromatin structure. For the four groups investigated, the heparin-initiated changes were dependent, in varying degree, on concentration and time. Group I showed a much more extensive sensitivity to heparin than group IV. Group II and III reacted similarly to group I or group IV, depending on the source, i.e., either a carcinoma-free stomach or a carcinoma-bearing stomach. Further extension of this method might yield information concerning the real premalignant potential of a specific case of chronic atrophic gastritis.

Chromatin↗
PubMed1983

[Frequency of kidney cyst wall cancer--results of 22,000 ultrasound studies].

In 22 198 sonographic examinations of the epigastric region, the authors identified 759 renal cysts (3.4%) and 165 renal tumours (0.74%). The percentage of incidence of the renal cysts is identical with that found in post-mortem examinations, whereas tumours were distinctly more frequent. Tumours of the cystic wall had been found in 0.5% of all sonographically diagnosed cysts and in 4% of renal cysts examined via fine-needle biopsy. Of the latter cysts (i.e. out of the 4% of cysts diagnosed by fine-needle biopsy), which were associated with tumours, two had been diagnosed as tumour suspects via sonography. Hence, the sonographic absence of abnormal findings in carcinoma of the renal cyst wall is rare. However, cysts diagnosed via sonography which cannot be subjected to fine-needle biopsy, should be rechecked and followed up at regular intervals. If all possible methods of diagnosis are utilised (I.V. urography, sonography, fine-needle biopsy guided by sonography, computed tomography, angiography), successful differential diagnosis of localised pathological conditions of the kidneys can be achieved in 97% of all cases. Patient risk and cost of diagnosis can be kept at a minimum by proceeding in steps as described in the article. Primary surgical exposure of the kidneys in case of a cystic renal process would now appear justified for therapeutic reasons only, not for the purpose of arriving at a diagnosis.

Adenocarcinoma↗
PubMed1983

Unusual clinical and histopathological findings in ocular sarcoidosis.

A 37-year-old Caucasian woman presented with a blind left eye and granulomatous panuveitis in the right eye. There was a subretinal neovascular membrane with haemorrhage beneath the macula and widespread subretinal lesions that were interpreted as choroidal granulomas in the right eye. A chest x-ray that showed diffuse pulmonary fibrosis without hilar lymphadenopathy was the only contributory clinical finding. Systemic and subconjunctival steroids and photocoagulation to the right macula brought about temporary remission. The painful left eye was enucleated. Histopathological examination revealed diffuse, noncaseating granulomas in the iris and ciliary body, retina, choroid, optic nerve, sclera and scleral emissaria, and inferior oblique muscle. A preretinal membrane was studied by electron microscopy. It was composed of a collagenous matrix containing fibroblasts and fibrous astrocytes. Some vessels, surrounded by a multilaminar basement membrane, revealed many features of normal retinal vasculature. Others were lined by markedly attenuated endothelial cells with occasional "open' junctions and fenestrations.

Adult↗
PubMed1983

[In vitro cultivation of vital tissue slices: a new variation of organ culture technics].

A new modification of the organ culture technique is described. In contrast to the conventional technique in which organ pieces (1 mm3) are cultivated, uniform, viable, microscopically controlled tissue slices are used in a modified organ culture technique. The new method is suitable for in vitro culture of human mammary carcinoma. Flow cytometry measurements reveal changes prior to and after collagenase treatment of human mammary carcinomas. In organ culture the composition of cell population prior to and after 48 h could be maintained. Examination under the microscope confirmed these results. The uptake of [3H]-thymidine was greater in tumor slices than in tumor pieces. Organ cultures sufficiently represent carcinoma in vivo in comparison to the other mentioned in vitro techniques.

Breast Neoplasms↗
PubMed1983

In vitro characteristics of a human mammary carcinoma prior to and after transplantation into nude mice.

Single cells from a patient (B.E., 65 years) have been isolated by collagenase treatment and cultivated in vitro. The human tumour showed predominantly simple undifferentiated and also tubular structures. The 5th in vitro passage of these cells were characterized by growth curves, DNA-distribution patterns and chromosome numbers. Cells of the 5th in vitro passage were i.p. transplanted in nude mice. The characteristics of the 21st passage of ascitic cells and solid tumour material grown in nude mice were compared with cell characteristics of the 5th in vitro passage. Our results demonstrate that malignant cells (ascitic) are best able to proliferate in vitro after transplantation into nude mice. The number of polyploid cells are increased in this cell population. DNA-distribution patterns and chromosome numbers show a good correlation. Biological properties of human neoplastic cells are dependent on environmental factors.

Aged↗
PubMed1983

[Dream interpretation: theory of the "psychological apparatus" as initial consciousness theory in Freud's metapsychology].

In the "Interpretation of Dreams" (1900 a) Freud presents for the first time a purely psychologically founded theory of psychic functioning, in the centre of which stands the model of the "psychic apparatus". In the detailed reconstruction of the statements of the "Interpretation" the present study tries to elaborate the meaning of "consciousness" within a psychology of the unconscious, in order to transfer--with reference to the early writings of J.-P. Sartre--the critique of Freudian unconscious to the level of the underlying conception of consciousness.

Arousal↗
PubMed1982

Biogenesis of mitochondrial ubiquinol:cytochrome c reductase (cytochrome bc1 complex). Precursor proteins and their transfer into mitochondria.

The precursor proteins to the subunits of ubiquinol:cytochrome c reductase (cytochrome bc1 complex) of Neurospora crassa were synthesized in a reticulocyte lysate. These precursors were immunoprecipitated with antibodies prepared against the individual subunits and compared to the mature subunits immunoprecipitated or isolated from mitochondria. Most subunits were synthesized as precursors with larger apparent molecular weights (subunits I, 51,500 versus 50,000; subunit II, 47,500 versus 45,000; subunit IV (cytochrome c1), 38,000 versus 31,000; subunit V (Fe-S protein), 28,000 versus 25,000; subunit VII, 12,000 versus 11,500; subunit VIII, 11,600 versus 11,200). Subunit VI (14,000) was synthesized with the same apparent molecular weight. The post-translational transfer of subunits I, IV, V, and VII was studied in an in vitro system employing reticulocyte lysate and isolated mitochondria. The transfer and proteolytic processing of these precursors was found to be dependent on the mitochondrial membrane potential. In the transfer of cytochrome c1, the proteolytic processing appears to take place in two separate steps via an intermediate both in vivo and in vitro. In vivo, the intermediate form accumulated when cells were kept at 8 degrees C and was chased into mature cytochrome c1 at 25 degrees C. Both processing steps were energy-dependent.

Animals↗
PubMed1982

Indication for thoracotomy and chest wall stabilization.

In multiply injured patients with major blunt thoracic injuries, the continued high mortality is mainly caused by the additive effect of the unstable flail chest associated with pleural and lung injuries upon the pulmonary gas exchange disturbance caused by haemorrhagic shock. A more active approach with early thoracotomy and chest wall stabilization is recommended. Three groups of injuries provide the appropriate indication: 1. Penetrating injuries, ruptures of organs and great vessels, when associated with serial rib fractures, which should be stabilized 'on retreat'. 2. Anterior or lateral wall instability due to double serial rib fractures with concomitant pleural and lung injuries. 3. Flail chest injuries with severe respiratory insufficiency. In all cases the thoracotomy should be performed after resuscitation of the patient on the day of the accident or within 3 days. Screwless elastic self-clasping rib plates were used in 15 multiply injured patients and in 5 isolated thoracic cases with good results and a low complication rate. The mortality was reduced from 64 per cent to 36 per cent in the patients with multiple injuries.

Adult↗