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Biomedical subjects

F X Bosch

Publications and source records attributed to F X Bosch.

At least 145 records · Page 8Linked to original sources
PubMed1987

Effect of riboflavin, retinol, and zinc on micronuclei of buccal mucosa and of esophagus: a randomized double-blind intervention study in China.

A randomized double-blind intervention trial was done in Huixian, People's Republic of China, a population with a high incidence of esophageal cancer. The aim of the trial was to determine whether a once-a-week treatment with retinol (15 mg or 50,000 IU), riboflavin (200 mg), and zinc (50 mg) could result, after 1 year, in a lower prevalence of precancerous lesions of the esophagus in the group receiving the active treatment as compared with the prevalence in the group receiving a placebo. The results of the trial, published elsewhere, indicated that the treatment had no effect on the prevalence of precancerous lesions of the esophagus. In determining whether an effect could be detected when earlier end points are used, the prevalence of micronuclei was evaluated in exfoliated cells from the esophagus and from the buccal mucosa in the present study. In a subsample of 200 out of the original 610 study subjects, smears were taken from the buccal mucosa before and after treatment, and in 170 subjects esophageal smears were obtained during endoscopy only after treatment. The smears were fixed and kept at room temperature over 1 year before being evaluated for the presence of micronuclei by means of 4'-6-diamidino-2-phenylindole fluorescent staining. Smears from approximately half of the subjects were considered suitable for evaluation. No statistically significant difference in the prevalence of micronuclei in the buccal mucosa cells was observed before and after treatment (the mean percentage of micronucleated cells in the vitamin group upon first examination, before treatment started, 0.35%; 1 year after treatment, 0.31%) or between the treatment and the placebo group at the final examination. (The mean percentage of micronucleated cells in the vitamin-treated group was 0.31 and 0.39% in the placebo group.) However, a statistically significant reduction (P = .04) was observed in the prevalence of micronuclei in esophageal cells in the treatment group as compared to the placebo. (The mean percentage of micronucleated cells in the vitamin-treated group was 0.19%; it was 0.31% in the placebo group.

Adult↗
PubMed1986

Studies on the temperature sensitivity of influenza A virus reassortants nonpathogenic for chicken.

Influenza A virus reassortants which are nonpathogenic for chickens are like mammalian influenza A viruses in that they are temperature sensitive for growth at 41 degrees C. We have investigated the mechanism of this temperature sensitivity using reassortants between the two highly pathogenic strains A/FPV/Rostock/34 (FPV, H7N1) and A/turkey/England/63 (TE, H7N3). These reassortants show a strict correlation between the pathogenicity for chickens and the constellation of the genes coding for the ribonucleoprotein complex, RNP. Evidence is presented which shows that all viral components are synthesized in sufficient amounts and that the block in the viral replication cycle at the nonpermissive temperature is a late one affecting virus maturation. It is suggested that the RNP, although still enzymatically functional, may lose its ability to interact normally with viral surface components, thus interfering with the process of virus maturation. Some of the nonpathogenic reassortants which possessed the neuraminidase of TE showed an interesting temperature-dependent phenomenon: the haemagglutinin synthesized at the elevated temperature could only agglutinate erythrocytes at 20 degrees C, when the neuraminidase was inhibited or the infected cells vigorously disrupted by ultrasonication. This phenomenon is possibly not directly related to the temperature-sensitive block.

Animals↗
PubMed1986

Cytokeratin expression in simple epithelia. III. Detection of mRNAs encoding human cytokeratins nos. 8 and 18 in normal and tumor cells by hybridization with cDNA sequences in vitro and in situ.

We describe cDNA clones of mRNAs encoding human cytokeratins nos. 8 and 18, and the amino acid sequences deduced from their nucleotide sequences. Human cytokeratin no. 8 is a typical cytokeratin of the basic (type II) subfamily, which is highly homologous to the corresponding bovine and amphibian (Xenopus laevis) proteins; however, unlike the amphibian protein, it does not contain glycine-rich oligopeptide repeats in its carboxyterminal 'tail' domain. Comparison with the reported amino acid sequences of two fragments of human 'tissue polypeptide antigen' (TPA), a widely used serodiagnostic carcinoma marker, revealed sequence identity, indicating that this serum component is derived from the intracellular cytokeratin no. 8 present in diverse kinds of epithelia and epithelium-derived tumors. Human cytokeratin no. 18 is very similar to the corresponding murine protein but contains two additional blocks of 4 and 5 amino acids in the 'head' portion. These cDNA clones and the RNA probes derived therefrom were used to detect specifically mRNAs by Northern-blot assays of RNAs from various carcinomas and cultured carcinoma cells. Using in situ hybridization on frozen sections of tumor-containing tissues, notably lymph nodes containing metastatic breast carcinoma, we were able to demonstrate the specificity and sensitivity of this procedure. The potential value for cell-biological research and pathology of being able to detect a mRNA encoding a given cytokeratin polypeptide in situ is discussed.

Amino Acid Sequence↗
PubMed1985

Chemotherapy versus chemotherapy plus hormonotherapy in postmenopausal advanced breast cancer patients. A randomized trial.

One hundred seventeen postmenopausal advanced breast cancer patients previously untreated with chemotherapy were randomized to receive: cyclophosphamide, methotrexate, and 5-fluorouracil (CMF), CMF and tamoxifen (TMX), and CMF and medroxyprogesterone (MAP). Treatments B and C induced a greater proportion of responses than treatment A. No effect was identified on the number of complete responses. After treatment failure, patients from groups A and C received Adriamycin (doxorubicin) (ADX) vincristine (VCR), and TMX and patients from group B received ADM, VCR, and MAP. No differences were found between the branches in the response rates to the second protocol. Responders to both treatments had a longer survival experience than nonresponders or responders to only one of the treatments. Survival was independent of the treatment group.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1985

Studies on the development of the charge heterogeneity of the influenza virus glycoproteins.

The heterogeneity in charge of the influenza virus glycoproteins, hemagglutinin (HA) and neuraminidase (NA) is retained, when glycosylation is inhibited by tunicamycin (TM) or 2-deoxyglucose (2-dg). This is in contrast to the charge heterogeneity of the G protein of vesicular stomatitis virus (VSV), which is mainly due to heterogeneous sulfation of the carbohydrate side chains and therefore is abolished by the above mentioned inhibitors of glycosylation. Thus, the charge heterogeneity of influenza virus glycoproteins might be attributable to some as yet unidentified modifications of the polypeptide backbone.

Animals↗
PubMed1984

Effect of inhibitors of glycosylation on proteolytic activation of avian influenza virus hemagglutinins: discrimination between tryptic cleavage and elimination of the connecting peptide.

The glycosylation inhibitors tunicamycin (TM), 2-deoxyglucose (2-dg), bromoconduritol (BC; 3,5/4,6-6-bromo 3,4,5-trihydroxycyclohex-1-ene), and N-methyl-deoxynojirimycin (MdN) have been used to study the role of glycosylation in the two proteolytic reactions involved in the biological activation of H7 influenza virus hemagglutinins (HAs): trypsinlike cleavage and subsequent elimination of the connecting peptide. The results obtained revealed that trypsin-like cleavage of the HAs of pathogenic strains does not require glycosylation, since these HAs were efficiently cleaved in the presence of TM and 2-dg. The elimination of the connecting peptide between HA1 and HA2, however, appears to require the transfer of oligosaccharides onto the HA polypeptide, since this activity was blocked by TM and by 2-dg. Elimination was not blocked by BC or MdN, which inhibit glucose trimming and subsequent conversion of the high-mannose type to the complex type of carbohydrate.

1-Deoxynojirimycin↗
PubMed1983

Evidence for the contribution of the host species to the extent of antigenic variation of N1 influenza virus neuraminidase.

N1 influenza virus neuraminidases (NA) derived from avian, swine and human virus isolates, including the genetically related classic strains A/FPV/Rostock/34, A/Swine/1976/31, A/PR8/34 and A/FM1/47, were analysed serologically by neuraminidase inhibition (NI), inhibition of virus release (IVR) and competitive radio-immunoassays (competitive RIA). Comparing the three tests, competitive RIA appeared to be more reliable than NI and IVR for a quantitative assessment of antigenic relatedness. Together with evidence presented by others, these studies indicate that the host species contributes to the extent of antigenic variation of NAses. In contrast to NAses of human viruses where antigenic drift occurs readily, NAses of animal influenza viruses, from birds or mammalians, undergo far fewer antigen changes.

Animals↗
PubMed1983

The accuracy of medical certifications of cancer deaths and of cancer diagnosis in the municipal area of Barcelona in 1979.

Death certificates containing a diagnosis of cancer concerning residents of the municipal area of Barcelona were matched against their clinical records to assess the accuracy of medical certifications of cancer death. Out of 2,945 cancer deaths, medical records were available in 1,557 (53%). Both documents were in agreement in 81% of the cases. Information on quality of cancer diagnosis was collected by considering the best evidence available derived from the techniques used. Histology of the primary was present in 67% of the cases. Histology of a metastatic deposit or positive cytology was the best evidence in 10% and other techniques -clinical, X-Ray or laboratory tests- were the best method used in 23%.

Death Certificates↗
PubMed1982

Cancer mortality in Barcelona 1960-1978.

Cancer mortality rates specific for sex and site for the 1960-1978 period are presented. The population covered is the municipal area of Barcelona. Rates have been adjusted taking as the standard population the Spanish census of 1970. Leading sites for males are lung, stomach and large intestine. Breast, large intestine and stomach are leading causes of death for females. Secular trends follow the general picture of the western industrial countries.

Aging↗
PubMed1982

The overall evolution of the H7 influenza virus haemagglutinins is different from the evolution of the proteolytic cleavage site.

It has been shown previously that the pathogenicity of avian influenza A viruses depends strictly on the proteolytic cleavability of their haemagglutinins (HAs) in infected cells. In this communication, pathogenic and non-pathogenic strains of the H7 subtype have been studied by comparing the genetic relatedness of their HA genes. Some of the cleavable HAs of pathogenic strains were genetically more closely related to the uncleaved HAs than to other cleavable HAs. These data clearly demonstrate that the overall evolution of the H7 haemagglutinins is different from the evolution of the specific cleavage site.

Biological Evolution↗
PubMed1980

Simple and rapid separation of ortho- and paramyxovirus glycoproteins.

The hemagglutinin (HA) and neuraminidase (NA) of influenza viruses, as well as the fusion protein (F) and hemagglutinin-neuraminidase (HN) of paramyxoviruses, have been separated in native form using a two-step procedure. The glycoproteins are efficiently extracted from virions using the on-ionic detergent octyl-beta-D-glucoside and are then applied to a column of agarose beads coupled with tyrosine-sulfanilic acid. Pure HA and F are obtained in good yield in the flow-through from this column. NA and HN bind strongly and can be eluted, albeit somewhat contaminated with HA or F, by raising the pH of the column buffer. The separated non-denatured fractions can be used for structural, functional, and antigenic studies.

Chromatography, Affinity↗