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Biomedical subjects

W Schwartz

Publications and source records attributed to W Schwartz.

At least 37 records · Page 2Linked to original sources
PubMed1985

Quantitative analysis of liver function in percutaneous transhepatic biliary drainage patients.

The diagnostic usefulness of Tc-99m DISIDA cholescintigraphy as a predictor of eventual catheter and hepatic function in patients who have undergone percutaneous transhepatic biliary drainage (PTBD) for extrahepatic biliary obstruction was evaluated. Twenty-nine cholescintigrams were performed in 14 patients. The examinations were divided into two groups: Group A (N = 17), in which the patient's clinical status deteriorated within two to three days post-PTBD, and Group B (N = 12), in which the patients did well clinically post-PTBD. No significant difference between the two groups was demonstrated by visual analysis of the analog images or by analysis of serum bilirubin levels. A computer program, developed by the authors, quantitates several parameters of DISIDA kinetics, reflecting hepatic function based upon compartmental analysis. A significant difference (P less than .001) was demonstrated between the mean transport constants (blood clearance constant = k1; hepatic clearance constant = k2) for the two groups. It is concluded that serum bilirubin levels and visual inspection of analog images are inadequate independent predictors of hepatic function in patients post PTBD. The transport constants k1 and k2 are quantitative parameters of hepatic function that may be of prognostic value in patients post PTBD.

Adult↗
PubMed1985

A prospective randomized comparison of epirubicin and doxorubicin in patients with advanced breast cancer.

Fifty-four patients with advanced breast cancer who had failed prior non-anthracycline combination chemotherapy were randomized to treatment with either epirubicin 85 mg/m2 or doxorubicin 60 mg/m2 intravenously every three weeks. Of 52 evaluable patients, 25% (six of 24) treated with epirubicin, and 25% (seven of 28) treated with doxorubicin experienced major therapeutic responses. The median duration of response to epirubicin was 11.9 months compared to 7.1 months with doxorubicin. Cardiotoxicity was monitored by serial multigated radionuclide cineangiocardiography performed at rest and after exercise. Laboratory evidence of cardiotoxicity was defined as a decrease in resting left ventricular ejection fraction of greater than 10% from the baseline value, or a decrease of 5% or greater with exercise compared with the resting study performed on the same day. Fifteen patients treated with epirubicin and 18 patients treated with doxorubicin had at least two determinations of left ventricular ejection fraction and were evaluable for laboratory cardiotoxicity. Using methods of survival analysis, the median doses to the development of laboratory cardiotoxicity were estimated to be 935 mg/m2 of epirubicin and 468 mg/m2 of doxorubicin. Four patients treated with epirubicin and five treated with doxorubicin developed symptomatic congestive heart failure. The median cumulative dose at which congestive heart failure occurred was 1,134 mg/m2 of epirubicin compared with 492 mg/m2 of doxorubicin. Fewer episodes of nausea and vomiting were observed in patients receiving epirubicin. Epirubicin is a new anthracycline with reduced cardiac toxicity, but preserved efficacy in the treatment of patients with advanced breast cancer.

Actuarial Analysis↗
PubMed1984

Internalization of colloidal gold-labelled insulin complexes into cultivated human smooth muscle cells.

The binding and internalization of colloidal gold-labelled insulin complexes into cultivated human arterial smooth muscle cells was studied. We could demonstrate that the colloidal gold-labelled insulin complex was bound to specific receptors on the cell surface of smooth muscle cells and internalized after 30 min at 20 degrees C. The gold-labelled insulin complexes entered the cell via vesicles and escaped from them in the cytoplasm. The biological activity of the complexes was determined by measuring their effect on DNA synthesis in smooth muscle cells and incorporation of (14C)-glucose into isolated fat cells. The binding characteristics of the complexes were examined by competitive inhibition of 125I-insulin binding to isolated fat cells in the presence of increasing concentrations of gold-labelled insulin complexes or unlabelled insulin. The gold-labelled insulin complex showed a growth promoting and metabolic effect and was able to compete with 125I-insulin for its binding sites.

Adipose Tissue↗
PubMed1984

Large surface proteins of hepatitis B virus containing the pre-s sequence.

The sequence of hepatitis B virus DNA contains an open reading frame which codes for a not-yet-identified protein of at least 389 amino acids. Only the products starting at the third (GP33/GP36) or the fourth (P24/GP27) initiation signal have been characterized as components of the viral surface antigen. We found a larger protein, P39, and its glycosylated form, GP42, in hepatitis B virus particles and viral surface antigen filaments. Immunological cross-reactions showed that P39/GP42 is partially homologous to P24/GP27 and GP33/GP36. The unique portion of its sequence bound monoclonal antibodies which had been induced by immunization with hepatitis B virus particles. Proteolytic cleavage patterns and subtype-specific size differences suggested that the sequence of P39 starts with the first initiation signal of the open reading frame. Its amino-terminal part (pre-s coded) is exposed at the viral surface and, probably, is highly immunogenic. A model is presented of how the open reading frame for the viral envelope leads to defined amounts of three different proteins.

Antibodies, Monoclonal↗
PubMed1984

The two concepts of action and responsibility in psychoanalysis.

I have presented two major concepts of action and responsibility which have a role in psychoanalysis and have been confused in the recent literature. Intentional action is the general action concept concerning consciously, preconsciously, or unconsciously enacted goal-directed behavior. Deliberate action is a type of intentional action, performed consciously or perhaps preconsciously, that involves a choice among specific possible ways of achieving a goal. Persons are ethically responsible for their deliberations and also responsible as the agent, deliberate or not, of the manifestations of their personal characteristics. Responsibility for mere agency is not the same as ethical responsibility, but since it is easy to confuse these two concepts they may be hazardous as features of clinical dialogue. Finally, "free will" and "determinism" are discussed as issues that historically attend the above subject matter. "Free will versus determinism" is argued to be a false issue properly replaced by Freud's actual interest in the "overdetermined" multiple motivations of behavior.

Dreams↗
PubMed1982

The bacteriologically battered baby: another case of Munchausen by proxy.

We present a case in which a mother who had had self-inflicted infections as a teenager also caused life-threatening infections in her year-old child. After testing for and treating various immunologic deficiencies without success, it was apparent that the infection was caused by contamination of intravenous sites. Strict isolation of the patient, with restricted and observed visitations by the mother, was the critical step in stopping the infections. Because the woman took her child to several emergency departments, this case is presented to alert emergency personnel to this entity and to explain some of the dynamics and the social issues that cause the problem.

Adult↗
PubMed1982

[Sirenomelia--the caudal regression syndrome (author's transl)].

A case of sirenomelia with malformations in lumbar and sacral spine and urogenital system together with fusion of lower limbs is presented. The caryotype of the child was normal 46XY. There were no hereditary diseases or diabetes in the family, though caudal regression syndrome is known to be more frequent with diabetic mothers. No exposures were known.

Abnormalities, Multiple↗
PubMed1982

[Leaching of uranium containing phosphorites with heterotrophic microorganisms].

The problem of heterotrophic leaching of metals was tested with uranium-containing phosphorites under laboratory conditions with regard to possible technical applications. As leaching agents we used the acids of citric and lactic acid fermentation, carried out with a strain of Aspergillus niger in sulfite liquor under different conditions and with lactic acid bacteria in wheye. Up to 12% uranium were soluted with citric acid fermentation of Marocco phosphorite containing 153 ppm U in Aspergillus niger cultures within 27 days.

Apatites↗
PubMed1981

Geomicrobiological leaching of tin minerals by Thiobacillus ferro-oxidans and organic agents.

Laboratory investigations confirm that it is possible to leach tin from synthetic minerals like stannite, kesterite, stannoidite, herzenbergite, ottemannite and berndtite, and from natural tin minerals which include stannite, cassiterite and varlamoffite, in the presence of Thiobacillus ferrooxidans, and with organic agents of biological origin, especially oxalic acid and oxalic-citric acids mixture. Over a leaching period of 35 days with 0.5% pulp density, initial pH of 2.5, using minus 0.16 mm size fraction at 32 degree C, as much as 54.45, 72.66, 97.13, and 31.30% Sn were extracted from synthetic stannite, kesterite, stannoidite and natural stannite, respectively. Varlamoffite, found in the dried, leached residues of the tin sulphides, provides evidence that bacterial action can be responsible for the genesis of supergene varlamoffite.

Citrates↗
PubMed1981

[Leaching of ores with heterotrophic microorganisms. Development of a screening method].

Besides leaching of sulfide ores with thiobacilli, a second way of microbial leaching is tested with carbon-heterotrophic fungi and bacteria for those types of ores, where thiobacilli fail to work. The active agents are metabolic products, f. i. organic acids, which are released into the medium producing water soluble compounds with heavy metals. A screening method is described for recognizing active strains in samples of soil, metal-containing sites, mining heaps and other biocoenoses, using the dilution method in plates with different media. The critical signs of supposed leaching activity are halo formations around growing colonies in turbid agar media with suspended particles of Ca carbonate or Ca phosphates of low solubility, and in a second group of experiments with insoluble compounds of heavy metals, f. i. oxides. The leaching activity was tested with metal compounds suspended in liquid media and inoculated with active strains of the screening program. First results were reached with oxides of copper (CuO), uranium (U3O8) and an uranium-containing phosphorite.

Bacteria↗
PubMed1981

[Geomicrobiological studies. XIV. Heavy metal tolerance of desulfurizing bacteria under various ecological conditions].

Tolerance and adaptation to heavy metals of Desulfovibrio- and Desulfotomaculum-strains of different origin have been investigated in enrichment cultures under different conditions of sulphate supply. Three groups of low, medium, and high toxicity were found with As, V, and Mo in the first, Ni, Sb, Co, and Hg in the second, and Cd, Zn, U, and Cu in the third group. If the SO"4-supply was restricted to heavy metal sulphates with a relation of 1:1 of heavy metal- and SO"4 -ions (2:3 with Sb2(SO4)3) the tolerance was somewhat lowered. Adaptation to higher concentrations of heavy metals was possible, if the strains had not yet been exposed and adapted to higher concentration levels at their natural habitats. The tolerance range of desulfurizers has been compared with the tolerance range of different biochemical types of microorganisms.

Bacillaceae↗
PubMed1980

Leaching of a silicate and carbonate copper ore with heterotrophic fungi and bacteria, producing organic acids.

Leaching of metals with carbon-heterotrophic microorganisms and organic acids as active agents has been performed with Timna copper ore containing 1.1% copper as carbonates and silicate and with some other metal oxides. Aspergillus niger surface cultures on a 14% sucrose fermentation medium yeilded 87.3% of total copper from 10% suspension within 2 weeks of leaching. On sulfite liquor as an industrial waste product A. niger solubilized 73.8% Cu within 4 weeks. In percolators with 14% sucrose medium up to 1780 ppm copper were found in solution. In leaching experiments with a sea water medium containing 7% sucrose only 684 ppm Cu were soluble. Leaching with lactobacilli containing whey yielded 83.4% of the total copper in 4 weeks.

Aerobiosis↗
PubMed1980

Effects of combined dopamine and nitroprusside therapy in patients with severe pump failure and hypotension complicating acute myocardial infarction.

In severe pump failure with hypotension complicating acute myocardial infarction, dopamine has been useful in raising arterial pressure by increasing myocardial performance and augmenting peripheral resistance. Once adequate blood pressure are obtained, vasodilators may be used to reduce peripheral resistance and thus enhance pump performance. Accordingly, the hemodynamic effects of dopamine and nitroprusside administration were monitored in eight patients who developed hypotension following an acute myocardial infarction. With dopamine therapy alone, mean arterial pressure averaged 84 +/- 3.6 mm Hg and mean left ventricular filling pressure 32 +/-7.9 mm Hg. The addition of nitroprusside, at doses ranging from 0.5 to 1.6 micrograms/kg/min, resulted in a decrease in arterial pressure to 75 +/- 2.4 mm Hg (p less than 0.01) and in left ventricular filling pressure to 23 +/- 7.2 mm Hg (p less than 0.001). Cardiac index increased modestly from 1.81 +/- 0.61 to 2.01 +/- 0.60 liters/min/m2 (p less than 0.05), while systemic vascular resistance fell from 1,967 +/- 707 to 1,586 +/- 634 dynes-sec-cm-5 (p less than 0.01). Heart rate did not change significantly. Seven of eight patients died in the hospital within 4 days of admission. It appears that despite a beneficial hemodynamic response effected by combined dopamine-nitroprusside administration, the prognosis of this group of patients may not be favorably altered because of the extensive destruction of myocardium.

Aged↗