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B Wolf

Publications and source records attributed to B Wolf.

At least 199 records · Page 11Linked to original sources
PubMed1991

[The use of bead cellulose for controlled drug liberation. 3. The ion exchange capacity of bead cellulose and bead cellulose derivatives].

Methods are represented for the preparation of the ionic derivatives dihydrogen-phosphate bead cellulose and carboxymethyl bead cellulose from pure, swollen bead cellulose. The degree of substitution can be varied by changing the extent of swelling of the parent bead cellulose and the amount of reactant. The products exhibit similar physical properties (swelling weight, porosity, bed volume and spherical shape) like pure, unsubstituted bead cellulose. The ion exchange capacity and pK values of bead cellulose derivatives were measured by a modified acid-base titration method. The tendency of varying the physical properties in relation to the degree of substitution is discussed.

Carboxymethylcellulose Sodium↗
PubMed1991

Preneoplastic lesions induced by myc and src oncogenes in a heterotopic rat colon.

With the use of viral vectors harboring myc and src oncogenes, we have assessed the potential contribution of these different elements to colonic neoplasia using a transplantation technique resulting in the formation of a heterotopic colon in Wistar Furth rats. While myc alone induced atypia and some dysplasia, src induced focal dysplastic lesions throughout the colon mucosa with evidence of metaplasia. In contrast, lesions induced by myc and src acting cooperatively, were highly dysplastic with evidence of tumor formation after protracted periods. These results indicated the formation of histologically distinct preneoplastic lesions elicited by the action of a single oncogene in colon implants with the production of adenocarcinomas when such oncogenic elements act cooperatively. This model provides an opportunity for studies of the action of different oncogenes, acting singly or in combination, in the multi-step progression to colon tumor formation.

Animals↗
PubMed1991

[Pregnancy continuation following patient education of primary abortion applicants].

Between 1972 and 1987 a total of 417 patients at the Department of Obstetrics and Gynaecology, Görlitz Hospital, changed their minds about an abortion after discussion with their doctor (average 5%, 1977 11.8%). A random survey (n = 176) was analysed, bearing in mind the medical and social aspects as well as the main reason for the planned abortion. It was established that the duration of pregnancy and birth in women who had changed the duration of pregnancy and birth in women who had changed their minds about an abortion did not differ from that of women who had not considered termination. However, a higher level of social care was needed.

Abortion, Legal↗
PubMed1991

[Repeat abortion--utilization and social influences].

The frequency of repeat abortions in the institution from 1972 to 1987 was analysed. In order to assess occurrence in the area, epidemiological characteristics were developed and their changes described in chronological order. Above all, the relationship between repeat abortion and selected social factors on influence was investigated. The effects of the practised system of care to reduce abortion frequency can be seen in the low rates and numbers of repeat abortions. The results of the investigation into repeat abortion enable clues to be deduced that can help in further reducing such repeat abortions.

Abortion, Legal↗
PubMed1990

cDNA sequences encoding rabbit latent kappa 1 b5 and b6 Ig L chains.

Regulation of rabbit Ig C kappa 1 L chain gene expression is thought to be under allelic control. Four nominal allotypic variants designated b4, b5, b6, and b9 have been found to be co-dominantly expressed at the C kappa 1 gene locus. Latent allotypes are nonallelic and appear as unexpected and transitory molecules in the serum as well as on B cell surfaces. To determine the mechanism of latent kappa 1 allotype expression, rabbits were initially induced to produce latent b5 and b6 allotypes by infection with Trypanosoma brucei and RNA was extracted from the lymph nodes of these rabbits. The polymerase chain reaction using allele specific oligonucleotide primers was used to detect and amplify the mRNA encoding the latent b5 and b6 sequences. Nucleotide sequence analysis of the cloned products revealed that the latent b5 and b6 cDNA sequences were identical to their nominal allelic counterparts, b5 and b6, respectively. Thus, the identification of transcripts encoding latent b5 and b6 sequences rules out serologic artifacts and idiotypic mimicry as explanations of latent allotype expression.

Animals↗
PubMed1990

[HIV-1 antigenemia and T-cell activation in HIV-1 infected patients].

In order to study a supposed association between T-cell activation in vivo and HIV-1-antigenemia in HIV-1-infected patients, the detection of p24-antigen in sera was correlated to serum levels of beta-2-microglobulin and C1q-binding immune complexes. Anti-p24-antibodies and the urinary excretion of neopterin were also analysed. In 24 of 80 patients (30%) p24-antigen could be detected, and in 15 of 59 (25.4%) there was a loss of anti-p24-antibodies. Tests revealed elevated serum levels of beta-2-microglobulin in 58 of 80 patients (72.5%), elevated levels of C1q-binding immune complexes in 15 of 66 (22.7%), and increased excretion of neopterin in 52 of 60 (86.7%). Detection of p24-antigen, loss of anti-p24-antibodies, serum levels of beta-2-microglobulin, and urinary excretion of neopterin were significantly correlated to advanced stages of HIV-1 infection. Patients with p24-antigen in the serum showed significantly more frequently elevated serum levels of beta-2-microglobulin and no significant association with increased urinary excretion of neopterin. Because of the high proportion of patients with elevated serum levels of beta-2-microglobulin and increased excretion of urinary neopterin in the absence of detectable p24-antigen in serum, we could not correlate HIV-1-antigenemia to T-cell activation in vivo.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Lipoamidase activity in human serum is due to biotinidase.

Lipoamidase, as determined by lipoyl-p-aminobenzoic acid (L-pABA) hydrolyzing activity, and biotinidase in human serum have similar pH profiles, molecular weights, thermostabilities, and are similarly inhibited by p-hydroxymercuribenzoate and not inhibited by phenylmethylsulfonylfluoride. A monospecific polyclonal antibody prepared against biotinidase immunoprecipitated greater than 95% of serum L-pABA hydrolyzing activity and an identical proportion of biotinidase activity. In addition, children with profound biotinidase deficiency (less than 10% normal serum activity) have greatly reduced levels of L-pABA hydrolyzing activity in serum (less than 15% of mean normal activity) and obligate heterozygotes have activities intermediate between that of normal and profoundly deficient individuals. These results indicate that most, if not all, of the L-pABA hydrolyzing activity in human serum is due to biotinidase. Moreover, since the Km of L-pABA hydrolysis by serum is high, it is unlikely that lipoic acid is recycled in the serum by biotinidase.

4-Aminobenzoic Acid↗
PubMed1990

Regulation of plasmin, miniplasmin, and streptokinase-plasmin complex by alpha 2-antiplasmin, alpha 2-macroglobulin, and antithrombin III in the presence of heparin.

The regulation of plasmin, miniplasmin, and streptokinase-plasmin complex (SkPm) was studied in vitro in the presence of unfractionated porcine intestinal heparin using purified plasma proteinase inhibitors. Heparin enhanced the reaction of antithrombin III (AT) with plasmin (up to 40-fold with 20 units/ml). The rate of plasmin inhibition by alpha 2-antiplasmin (alpha 2AP) and by alpha 2-macroglobulin (alpha 2M) was not changed by heparin (0.5-100 units/ml); the rank-order of plasmin-inhibitory activity remained alpha 2AP greater than alpha 2M greater than AT. The reaction of miniplasmin with AT was studied also. The second order rate constant was 9.2 x 10(2) M-1s-1 without heparin and 2.6 x 10(4) M-1s-1 in the presence of 20 units/ml heparin. Heparin did not affect the rank-order of miniplasmin-inhibitory activity; it remained alpha 2M greater than alpha 2AP greater than AT. While the reaction of AT with SkPm was negligible, heparin stimulated this reaction dramatically. The SkPm-inhibitory activity of alpha 2AP was not changed by heparin. When plasma concentrations of alpha 2AP (1.05 microM) and AT (4.76 microM) were compared, AT inhibited greater amounts of SkPm in the presence of more than 5 units/ml of heparin. The increased SkPm-inhibitory activity of AT in heparin did not result from SkPm dissociation, and heparin did not decrease the rapid rate of streptokinase association with plasmin. These studies demonstrate that heparin can affect the regulation of fibrinolysis at multiple levels of the enzyme cascade.

Animals↗
PubMed1990

Rabbit Ig kappa 1b6 gene structure.

Previous studies employing Southern blot analyses have detected multiple kappa-homologous sequences within EcoRI-digested DNA isolated from kappa 1b6 homozygous rabbits and kappa 1b6 L chain secreting RMH H158 cell line. These results are very unexpected because the published partial protein sequence for the kappa 1b6 C region is incompatible with an EcoRI restriction endonuclease recognition sequence at the nucleotide level for this allotype. To determine their identity, the kappa-homologous sequences were isolated from DNA extracted from a kappa 1b6 L chain secreting RMH H158 cell line by molecular cloning. Structural analyses demonstrated these sequences to contain genetic information encoding the majority of the kappa 1b6 L chain gene locus. The protein sequence deduced from the kappa 1b6 C region gene was shown to differ from the published partial kappa 1b6 C region protein sequence at five amino acid positions. One of these differences results in a glycine to serine interchange that introduces an EcoRI restriction endonuclease recognition site within the kappa 1b6 C region gene. Subsequent genomic Southern blot analyses confirmed this structural assignment. Based on these data, the EcoRI-sensitive kappa-homologous fragments present within the genomes of the RMH H158 cell line and kappa 1b6 homozygous rabbits represent the nominal kappa 1 gene and not an alternative kappa isotype or kappa pseudogene. Rabbit Ig kappa 1 allelic nucleotide sequence homology comparisons have shown the isolated kappa 1b6 J-C gene locus to display common structural features previously identified in other kappa 1 alleles.

Amino Acid Sequence↗
PubMed1990

[Electron energy loss spectroscopy (EELS) as a method for the localization of antigens and other substances in cells and tissues].

The localization of antigens and other substances in cells and tissues by electron microscopy is usually performed by immunohistochemical techniques employing labelled conventional or monoclonal antibodies. For the ultrastructural localization of the antibodies, they are coupled to electron-dense labels like gold or ferritin. Here, we demonstrate a novel method to localize antigens in cells, tissues, and on other supports. By electron energy loss spectroscopy (EELS) it is possible to directly analyze the distribution of antigens, metabolites or other substances without the use of labelled antibodies: as an example we demonstrate the distribution of the immunomodulator lipopeptide in B lymphocytes and macrophages. EELS represents a novel, sensitive, and generally applicable method for the detection and localization of antigens and other substances in biology and medicine.

Adjuvants, Immunologic↗
PubMed1990

Biotinidase.

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Amidohydrolases↗
PubMed1990

Determination of second messengers and protein kinase C in bone marrow derived macrophages stimulated with a bacterial lipopeptide.

The synthetic lipopeptide Pam3Cys-Ala-Gly, an analogue of the N-terminal part of bacterial lipoprotein, constitutes a potent macrophage activator. The role of protein kinase C (PKC) in lipopeptide induced signal transduction was investigated. As determined by enzymatic and immunochemical methods, translocation of PKC could not be observed in lipopeptide stimulated bone marrow derived macrophages. Our studies showed that the membrane-associated form of PKC displayed different characteristics than the cytosolic form. The second messengers, inositoltrisphosphate, cAMP and cGMP, did not seem to be involved in signal transduction. Unlike LPS, Pam3Cys-Ala-Gly induced a rapid rise in cytosolic Ca2+, which was due to an influx of extracellular calcium as well as to a redistribution of intracellular calcium. The data suggest that one major intracellular signal transduction mechanism initiated by lipopeptide consists of altering internal Ca2+ concns.

Amino Acid Sequence↗
PubMed1990

Biotin uptake in cultured hepatocytes from normal and biotin-deficient rats.

Biotin uptake was studied in isolated cultured hepatocytes of normal and biotin-deficient rats. Biotin uptake was temperature-dependent with respect to physical, but not to chemical, processes, proportional to the exogenous biotin concentration in the medium, independent of pH and sodium ion concentrations of the medium, and uneffected by the presence of structural analogues of biotin or metabolic inhibitors in both normal and biotin-deficient hepatocytes. These results suggest that biotin uptake occurs by a passive, nonmediated, non-energy-dependent mechanism in rat hepatocytes.

Animals↗
PubMed1990

Partial biotinidase deficiency: clinical and biochemical features.

Neonatal screening for profound biotinidase deficiency (less than 10% of the mean normal activity level) has identified a group of children with partial biotinidase deficiency (10% to 30% of mean normal activity). Because partial biotinidase deficiency may result in clinical consequences that may be prevented by treatment with biotin, we evaluated such individuals and their family members (1) to determine whether partial biotinidase deficiency is associated with symptoms and (2) to determine the inheritance pattern. We quantified serum biotinidase activity levels and obtained medical histories of probands, their parents and siblings, and additional family members. All children with partial deficiency were healthy at the time of diagnosis. One child, who was not initially treated with biotin, later developed hypotonia, hair loss, and skin rash, which resolved with biotin therapy. Four adults and three children with partial biotinidase deficiency were identified among family members of infants identified by neonatal screening. All these individuals were healthy, although one sibling had elevated urinary lactate excretion. A fifth adult with partial deficiency, found among clinically normal adult volunteers, later showed minor symptoms that resolved after biotin therapy. Like children with profound biotinidase deficiency, children with partial biotinidase deficiency are symptoms free at birth. However, the subsequent occurrence of symptoms of profound biotinidase deficiency in some persons with partial deficiency suggests that biotin therapy for this condition may be warranted.

Adult↗