[Prognostic factors in stomach cancer. Results of a uni- and multivariate analysis].
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Actuarial Analysis↗
Biomedical subjects
K Becker
Publications and source records attributed to K Becker.
Onchocerciasis in Minnesota cattle.
Umbilical hides from 536 dairy cattle in Minnesota were tested for the microfilarial stage of Onchocerca species to determine the distribution of onchocerciasis in the state. The infection was widespread as microfilariae were obtained from 214 (40%) of the animals, representing nearly all areas of the state. Adult Onchocerca parasites were collected primarily from nodules associated with tibial bones but also were found to a lesser extent within the gastrosplenic ligament. Specific identity of these organisms is unclear as they exhibit certain morphological features previously described as being characteristic of either Onchocerca gutturosa, Onchocerca lienalis, or Onchocerca stilesi.
Animals↗
Pharmacodynamic and pharmacokinetic aspects of iodo-doxorubicin.
Iodo-doxorubicin (I-DOX) is a new doxorubicin (DOX) analog presently in phase II clinical trials in Europe. This drug is similar to DOX in its metabolism but differs in its pharmacokinetics. We describe correlations between pharmacokinetic parameters and toxicity. There is a linear relationship between the dose in mg/m2 and the nadirs of the reduction in white blood cells (WBC), neutrophils (PMN), platelets (PLT), and hemoglobin (HB). Furthermore, a linear correlation exists between the dose in mg/m2 and the area under the curve (AUC) of I-DOX. The relationship between the AUC of I-DOX and the reduction of PMNs plotted on a logarithmic scale shows a sigmoidal curve, whereas no such correlation was found between I-doxorubicinol, the major cytostatic metabolite, and the reduction in PNMs. The variation in the AUC for I-DOX correlated with the relative amount of metabolism of I-DOX. A correlation existed between the relative amount of metabolism of I-DOX and the reduction in PNMs. These results may have an impact on the evaluation of I-DOX in phase II trials, since a sound understanding of the pharmacokinetic/pharmacodynamic relationships can yield important information for minimizing unacceptable toxicity during phase II, as well as phase III, trials.
Biotransformation↗
Histopathologic characteristics of early adenocarcinoma in Barrett's esophagus.
To elucidate the early events of cancer development in the columnar cell-lined lower esophagus, 13 esophagectomy specimens with early adenocarcinoma (T1) were histopathologically studied and the morphometry of the lesion was performed on a histologic map. Eleven (84.6%) of the 13 early Barrett's carcinomas were contiguous to both the distinctive specialized-type Barrett's mucosa and squamous epithelium. Furthermore, ten (76.9%) of the 13 tumors had residual squamous islands on the surface. These data suggest that carcinomas in Barrett's esophagus mostly develop at a place very close to the squamocolumnar epithelial border. The distance from the tumor center to the nearest squamous epithelium, including squamous islands, was 2 cm or less in all cases but one. Therefore, the authors conclude that the primary site of cancer development in Barrett's esophagus is the metaplastic columnar-lined area, particularly of specialized type, within 2 cm from the squamocolumnar epithelial border.
Adenocarcinoma↗
[Malignant lymphoma associated with HIV infection].
The course of disease in 119 HIV-infected patients (117 men, 2 women; median age 38.5 years) with malignant tumours other than Kaposi's sarcoma was analyzed in a multi-centre retrospective study. This was conducted to obtain initial information concerning the incidence, clinical features and results of therapy in HIV-associated neoplasms, especially malignant lymphomas. The most frequent tumour was malignant non-Hodgkin's lymphoma (98 patients, 82.5%), seven patients had Hodgkin's disease, five had solid tumours, four a polyclonal lymphoproliferative syndrome, three an acute lymphocytic leukaemia, and two had other lymphoproliferative diseases. 58% of the non-Hodgkin's lymphomas occurred in patients with marked immunodeficiency, 85% were high grade malignancies and 47% had primary extranodal disease. 56% of primary nodal lymphomas also had visceral spread (Stage IV). Lymphoblastic non-Hodgkin's lymphoma was more common in patients with favourable immunological status, presented less frequently with primary extranodal disease, was diagnosed earlier than other non-Hodgkin's lymphomas, and appeared to carry a better prognosis. 78 out of the 98 patients with non-Hodgkin's lymphoma had been treated, 66 with cytotoxics. The median survival time was 6 months. Longer remission periods, of at least 12 months, were seen in ten of the 78 patients (13%). Despite the overall poor prognosis and the pre-existing immune defect, palliative (chemo-)therapeutic measures are both justified and promising, and may also result in life-prolonging remissions.
Adult↗
Influence of some prostaglandin-analogues on mouse skin allograft survival compared to dexamethasone. Possible role of thromboxane.
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Animals↗
Immunoglobulin VH and VK genes of the BALB/c anti-foot-and-mouth disease virus (O1) VP1 response: cloning, characterization and transgenic mice.
Hybridomas producing monoclonal antibodies of different isotypes were isolated from BALB/c antibody responses to the capsid protein VP1 of the foot-and-mouth disease virus (FMDV) strain O1. According to antigen binding measured by ELISA a weak-binding (81D10, IgM) and a strong-binding antibody (113C12, IgG2a) were selected. As RNA sequencing of productive immunoglobulin VH and VK genes turned out, both chains of the weak-binding antibody (81D10) are encoded by germline (i.e. not mutated) genes whereas the gene encoding the strong-binding antibody (113C12) k chain is mutated at several sites. Therefore, rearranged VH and VK genes of 81D10 were cloned, expressed in immunoglobulin non-producing plasmacytoma cells, and mice transgenic for the 81D10 k gene were produced. These mice provide a first step in the development of a transgenic mouse model for genetical investigations in the affinity maturation of anti-viral immunoglobulin variable genes.
Animals↗
Influence of aminophylline and ketotifen in comparison to the lipoxygenase inhibitors NDGA and esculetin and the PAF antagonists WEB 2170 [correction of 2107] and BN 52021 on endothelin-1 induced vaso- and bronchoconstriction.
Theophylline (p less than 0.05) and ketotifen (p greater than 0.05) markedly reduced, but the lipoxygenase inhibitors and PAF receptor antagonists were without any influence on the endothelin-1 (ET-1 1 nmol/kg i.v.) induced increase of pulmonary inflation pressure of anaesthetised and ventilated guinea-pigs. The ET-1 induced increase in mean arterial blood pressure as well as the secondary TXB2 release into bronchoalveolar lavage fluid or plasma was not decreased. TXB2 release cannot be the only mechanism of bronchopulmonary ET-1 effects in guinea-pigs in vivo.
Aminophylline↗
Protein folding causes an arrest of preprotein translocation into mitochondria in vivo.
With vital yeast cells, a hybrid protein consisting of the amino-terminal third of the precursor to cytochrome b2 and of the entire dihydrofolate reductase was arrested on the import pathway into mitochondria. Accumulation of the protein in the mitochondrial membranes was achieved by inducing a stable tertiary structure of the dihydrofolate reductase domain. Thereby, three salient features of mitochondrial protein uptake in vivo were demonstrated: its posttranslational character; the requirement for unfolding of precursors; and import through translocation contact sites. The permanent occupation of translocation sites by the fusion protein inhibited the import of other precursors; it did, however, not lead to leakage of mitochondrial ions, implying the existence of a channel that is sealed around the membrane spanning polypeptide segment.
Aminopterin↗
High-dose versus intermediate-dose cytarabine combined with mitoxantrone for the treatment of relapsed and refractory acute myeloid leukemia: results of an age-adjusted randomized comparison.
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Age Factors↗
[Experimental animal studies for the detection of circulating Toxoplasma antigens].
Rabbits and mice were infected by Toxoplasma gondii (RH and HanR) and Hammondia hammondi. An enzyme immunoassay with monoclonal antibodies was used to reveal circulating Toxoplasma antigens. They were found only in mice and rabbits that had been infected by the cyst-forming strain Toxoplasma HanR. In mice infected by Hammondia hammondi low antibodies titres were found that showed a cross-reaction with Toxoplasma. The enzyme immunoassay for evidence of Toxoplasma antigens demonstrated a negative reaction in these animals.
Animals↗
[Analgesic nephropathy (AN) with special reference to capillary sclerosis. A multicenter study from the former East Germany].
The incidence of capillary sclerosis in the mucosa of the upper urinary tract was beyond expectation, according to a multicenter study conducted at 11 pathological institutes in all regions of the former GDR from which the following more specific findings were obtained: Capillary sclerosis was recorded primarily from women (1.4:1) in 3.6% of 3,929 autopsy cases (minimum age being 40 years). This result has close to the outcome of a study conducted in Basle, Switzerland, though highest severity (0.33%) and the complete morphological picture of analgesic nephropathy (0.54%) were clearly less frequent, as compared to the above Swiss findings. No reliable conclusion can as yet be drawn regarding the infrequent case of renal pelvis carcinoma. Epidemiological and clinical studies are likely to suggest that an increase in findings might be expected in this part of Germany and might be aetiologically attributable to abuse of analgesics.
Adult↗
Protein-chemical standardization of the erythrocyte glutathione reductase activation test (EGRAC test). Application to hypothyroidism.
The erythrocyte glutathione reductase activation coefficient (EGRAC) is an index of riboflavin deficiency or, more exactly, of FAD deficiency in man. In this report a sensitive version of the EGRAC test is introduced that is based on the molecular properties of glutathione reductase and its FAD-free apoenzyme. The hemoglobin concentration of the blood sample can be estimated simultaneously using the spectrophotometric absorption at 340 nm. - The method was tested for 33 thyroidectomized patients in comparison with a euthyroid control group. From the average EGRAC values (1.40 vs. 1.22) it was deduced that the average free FAD level was approximately 2 times lower for the patients' than for the control group. Discussed is the role of the EGRAC test in hormonal and nutritional disorders.
Adult↗
Contact sites between inner and outer membranes: structure and role in protein translocation into the mitochondria.
Contact sites between both mitochondrial membranes play a predominant role in the transport of nuclear-coded precursor proteins into mitochondria. The characterization of contact sites was greatly advanced by the reversible accumulation of precursor proteins in transit (translocation intermediates). It was found that the sites are saturable, apparently contain proteinaceous components and mediate extensive unfolding of the polypeptide chain in translocation. Some components of mitochondrial contact sites are currently being identified.
Animals↗
Flavin analogs with antimalarial activity as glutathione reductase inhibitors.
10-(4'-Chlorophenyl)-3-methylflavin has antimalarial activity in vitro and in vivo (Cowden et al., J Med Chem 31: 799, 1988). This flavin analog and two of its derivatives were found to inhibit the antioxidant flavoenzyme glutathione reductase from human erythrocytes in its isolated form as well as in hemolysates. The mixed-type inhibition was completely reversible, the Ki-values being of the order of 1 microM. Surprisingly, the drugs were not competitive with FAD, but with GSSG, one of the enzyme's substrates. Malaria parasite glutathione reductase, extracted from Plasmodium falciparum, could also be inhibited by the compounds. Studies on the effects of the substances on P. falciparum in vitro, which were demonstrated morphologically and by growth inhibition, confirmed previous observations with 10-(4'-chlorophenyl)-3-methylflavin and showed similar parasiticidal characteristics for the two new derivatives. The activities of five other erythrocytic enzymes tested were not impaired by the drugs, nor was the nucleotide metabolism of erythrocytes and/or parasites significantly changed. Permeation into red blood cells was demonstrated for one compound by 19F-NMR-spectroscopy. Inhibition of glutathione reductase might contribute to, or account for, the antimalarial activity of this group of flavin analogs.
Animals↗
Iron(III)hydroxamate transport of Escherichia coli K12: single amino acid replacements at potential ATP-binding sites inactivate the FhuC protein.
The mechanism of iron(III)hydroxamate transport appears to be of the periplasmic binding protein dependent transport (PBT) kind which is energized by ATP hydrolysis. The FhuC protein contains two domains typical of ATP-binding proteins. Lysine in domain I was replaced by glutamine and glutamate, and aspartate in domain II by asparagine and glutamate, resulting in FhuC derivatives which no longer transported ferrichrome and albomycin. FhuC inactivation by the aspartate-glutamate substitution is especially noteworthy since the negative charge thought to be involved in Mg2(+)-ATP binding remains the same and the two amino acid side chains differ in only a CH2 group. It is concluded that the two domains that represent consensus sequences among all peripheral cytoplasmic membrane proteins of PBT systems are involved in substrate transport.
ATP-Binding Cassette Transporters↗
Influence of some prostaglandins and prostaglandin analogues on PAF-induced shock in mice.
Prostaglandins and Prostaglandin-analogues were investigated for their ability to protect mice from platelet-activating factor (PAF) induced shock. 75% mortality in female NMRI mice was induced by i.v. injection of 75 micrograms/kg PAF. Nileprost and PGE1, the most potent substances, produced a dose dependent protection against PAF. Iloprost and PGI2 were less effective. PGE2, nalador, flunoprost and U 46619 were neither protective nor deleterious. The strong difference in the effectiveness between the two prostaglandins of the E-series and the poor effect of PGI2 and the PGI2 analogue is remarkable. Flunoprost and U 46619 that increased the TXB2 synthesis or release in two experimental models did not enhance the PAF mortality; TXA2 seems to be only a secondary mediator of the acute PAF-induced death.
Animals↗
Antimalarial activity of the ethanol/alcohol oxidase system in vitro.
Among other macrophage secretory products, H2O2 plays an important role in the host's defense against malaria (Wozencraft et al., Infect. Immun., 43, 664, (1984]. In our in vitro studies on the human malaria parasite Plasmodium falciparum, hydrogen peroxide was produced by the alcohol oxidase-catalyzed reaction ethanol + O2----acetaldehyde + H2O2 (EC 1.1.3.13). At concentrations of 8.7 mM (= 0.5%) ethanol and 0.1 U alcohol oxidase per ml culture, more than 95% of the parasites were irreversibly damaged. Acetaldehyde was found to be parasiticidal per se--probably by releasing immature forms of P. falciparum from erythrocytes--but CH3CHO concentrations as high as 90 mM were required for complete elimination of the parasites. Ethanol (less than 20 mM) or alcohol oxidase alone had no significant effect on parasite viability. As discussed, the ethanol/alcohol oxidase system might be of interest as a potential chemotherapeutic principle, especially since metabolism and pharmacology of the substrates and products are well understood.
Acetaldehyde↗