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Biomedical subjects

B Kopp

Publications and source records attributed to B Kopp.

12 recordsLinked to original sources

Cardenolides from Adonis aestivalis.

Four cardenolides were isolated for the first time from the aerial parts of Adonis aestivalis. The compounds were identified by spectrometry and for 3-epi-periplogenin, helveticoside also by comparison with authentic substances. Two new cardenolides were structurally elucidated: strophanthidin-3-O-beta-D-digitoxosido-alpha-L-cymarosido-be ta-D-glucoside and strophanthidin-3-O-beta-D-digitoxosido-beta-D-digoxoside-bet a-D-diginosido-beta-D-glucoside.

Carbohydrate Sequence

Neuropsychological indicators of the vulnerability to schizophrenia.

Schizophrenia is associated with enduring deficits in neuropsychological functioning. It is widely undecided if the various aspects of neuropsychological impairment are a consequence of the disorder or if they are also present premorbidly and in populations at increased risk for schizophrenia (vulnerability markers). Neuropsychological deficits in healthy relatives of schizophrenic patients who are at an elevated risk for schizophrenia and who did not yet pass the period of risk would indicate that these deficits are vulnerability markers. This hypothesis was tested for three neuropsychological paradigms which have been proven to distinguish schizophrenic patients from controls. 33 siblings of drug-free schizophrenic probands revealed deficits has compared to 33 matched healthy controls in a blurred single target version of the Continuous Performance Test and in a multiple item version of the Span of Apprehension Test but not so in less difficult versions of both tests or in the time needed to react to stimuli with shifting modality.

Adult

Analysis of some Malaysian dart poisons.

An investigation of nine Malaysian dart poisons has confirmed that their main active components are cardenolides from Antiaris toxicaria (Pers.) Lesch. and alkaloids probably from different forms of Strychnos ignatii P. Bergius. It is not possible to determine the ethnic origin of the poisons from the results of the analyses on their own. Two new cardiac glycosides have been isolated and their structures determined as 12 beta-hydroxycannogenin 3 beta-O-beta-D-deoxygulopyranoside and 3 beta-O-alpha-L-rhamnopyranoside, respectively.

Alkaloids

The Moraceae-based dart poisons of South America. Cardiac glycosides of Maquira and Naucleopsis species.

The use of cardenolide-containing Moraceae in the dart poisons of South America is reviewed. Those prepared by the Chocó Indians of western Colombia--called niaará or kieratchi--have probably been made from the latex of Naucleopsis amara and N. glabra. In Ecuador, the Colorado Indians used N. chiguila, while the Coaiquer Indians still derive a poison from the latex of N. naga and the Cayapá Indians occasionally make use of a blowgun poison, hambi, which probably also comes from a Naucleopsis species. The Kaborí (Rio Uneiuxi Makú) Indians of north-western Brazil may have utilized Maquira coriacea, but a more recent collection documents N. mello-barretoi latex as a source of their poison. The Tikuna Indians of western Brazil included leaves and bark of N. stipularis in one of their poisons. The principal cardiac glycosides present in Maquira species are strophanthidin-based and the main ones occurring in Naucleopsis species are antiarigenin- as well as strophanthidin-based. The structures of two new glycosides, isolated from dart-poison samples, have been established as strophanthidin beta-D-glucomethylosido-D-alloside and beta-D-digitoxosido-D-alloside. The former is a major component of pakurin, the crystalline glycoside mixture prepared by Santesson in 1928 from a Chocó Indian poison.

Animals

CA15.3, MCA, CAM26, CAM29 are members of a polymorphic family of mucin-like glycoproteins.

The monoclonal antibodies that define the tumor markers CA15.3, MCA, CAM26 and CAM29 were found to react with coexisting epitopes present on mucin-like glycoproteins. Despite their immunologic relationship, the markers showed distinct concentration levels in various body fluids. Particularly, MCA and CAM26 were high in urine and amniotic fluid. Sera collected from pregnant or lactating women and especially human milk samples contained considerable amounts of CAM29 and MCA, but comparably small quantities of CAM26 and CA15.3. The concentrations of CA15.3, MCA, CAM26 and CAM29 were correlated in serum samples from patients with metastatic breast cancer. The discrepancy between immunologic relationship and dissimilar biologic behavior could be explained by a limited coexistence of epitopes on subsets of heterogeneous polymorphic mucins. All mucin markers which were investigated showed improved sensitivity for metastatic breast cancer compared with the established marker CEA.

Adolescent

[Nd:YAG laser synechiolysis in glaucoma due to iridocorneal angle synechiae].

Seven patients with chronic angle-closure glaucoma and medically uncontrollable intraocular pressure were treated with the Q-switched Nd:YAG laser. Goniosynechiolysis was achieved at least partially. Follow-up time was 6-17 months. By means of additional monotherapy with a local beta-blocking agent where necessary, intraocular pressure was regulated to below 21 mm Hg in 5 of 7 patients. There were no severe complications. In selected cases Nd:YAG goniosynechiolysis may represent an effective means of lowering intraocular pressure.

Acetazolamide

Cholecystokinin in the inhibition of gastric secretion and gastric emptying in humans.

Cholecystokinin (CCK) is known to inhibit gastric acid secretion and gastric emptying but its physiological role in the inhibition of gastric functions is not settled. In this study performed on 16 young male subjects, gastric acid secretion and emptying rate were determined after intragastric administration of 8% peptone meal alone or in combination with intravenous infusion of graded doses of CCK-8 (5-80 pmol/kg.h) or with addition of vegetable oil to meal without or with pretreatment with loxiglumide, a specific CCK antagonist. CCK-8 infusion at lower dose (5 pmol/kg.h) was ineffective but at higher doses (20-80 pmol/kg.h) it resulted in a significant reduction in acid output by 39 and 43% and a decrease in gastric emptying from 54% to 40 and 22%, respectively. Pretreatment with loxiglumide abolished almost completely the inhibition of both gastric acid and gastric emptying by CCK-8. Fat added to peptone meal reduced gastric acid secretion by 42-65% and decreased gastric emptying to 24-32%. The pretreatment with loxiglumide tended to reduce fat-induced inhibition of gastric acid secretion and gastric emptying but the difference in the inhibition of gastric functions between the tests without and with loxiglumide was not significant. This study provides evidence that exogenous CCK administered at pharmacological doses is a potent inhibitor of gastric acid secretion and gastric emptying and probably acts via specific CCK receptors. In contrast, fat induces inhibition of gastric acid secretion and gastric emptying that cannot be fully attributed to hormonally acting CCK.

Adult

Studies on the immobilization of glucuronidase (Part 2). Cleavage of hardly soluble substrates in organic solvents.

Naturally occurring glucuronides and glucosides dissolved in organic solvents can be split with the help of beta-glucuronidase (EC 3.2.1.31) immobilized on controlled pore glass. To protect the enzyme against denaturation by the organic solvents and to promote hydrolytic cleavage of substrates, two methods were used: (a) Immobilization via crosslinking with aged glutaraldehyde in presence of bovine serum albumin; and (b) Adsorption of wet enzyme to the carrier in the presence of organic solvents.

Cross-Linking Reagents

Sensitive bioassay for vancomycin.

An accurate and sensitive assay for vancomycin in serum and body fluids has not been available. This paper reports an assay for vancomycin that can detect serum and fluid levels as low as 0.8 mug/ml. A disk diffusion technique was designed employing buffered glucose minimal salts agar and Bacillus subtilis as an indicator strain. A linear relationship was obtained between zone diameter and concentration for vancomycin standards from 0.8 to 50 mug/ml prepared in pooled human serum. Results were accurate (<10% error) and reproducible (within-sample standard deviation, 0.25 mug/ml) for concentrations of from 0.8 to 25 mug of vancomycin per ml. Zone diameters were at least 6 mm larger on minimal salts agar than on standard assay media. The increased sensitivity and accuracy of the assay make it possible to accurately measure levels in cerebrospinal fluid and dialyzate fluid as well as in serum.

Adult