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Biomedical subjects

V Gruber

Publications and source records attributed to V Gruber.

14 recordsLinked to original sources
PubMed2001

N-glycosylation potential of maize: the human lactoferrin used as a model.

In order to determine the N-glycosylation potential of maize, a monocotyledon expression system for the production of recombinant glycoproteins, human lactoferrin was used as a model. The human lactoferrin coding sequence was inserted into the pUC18 plasmid under control of the wheat glutenin promoter. Maize was stably transformed and recombinant lactoferrin was purified from the fourth generation seeds. Glycosylation was analysed by gas chromatography, lectin detection, glycosidase digestions and mass spectrometry. The results indicated that both N-glycosylation sites of recombinant lactoferrin are mainly substituted by typical plant paucimannose-type glycans, with beta1,2-xylose and alpha1,3-linked fucose at the proximal N-acetylglucosamine, and that complex-type glycans with Lewis(a) determinants are not present in maize recombinant lactoferrin.

Blotting, Western↗
PubMed2000

Triple helix assembly and processing of human collagen produced in transgenic tobacco plants.

The use of tobacco plants as a novel expression system for the production of human homotrimeric collagen I is presented in this report. Constructs were engineered from cDNA encoding the human proalpha1(I) chain to generate transgenic tobacco plants expressing collagen I. The recombinant proalpha1(I) chains were expressed as disulfide-bonded trimers and were shown to fold into a stable homotrimeric triple helix. Moreover, the recombinant procollagen was subsequently processed to collagen as it occurs in animals. Large amounts of recombinant collagen were purified from field grown plant material. The data suggest that plants are a valuable alternative for the recombinant production of collagen for various medical and scientific purposes.

Amino Acid Sequence↗
PubMed1999

Structure, organization and expression of two closely related novel Lea (late-embryogenesis-abundant) genes in Arabidopsis thaliana.

We have isolated and sequenced a 9.5 kb genomic region from A. thaliana, located on chromosome 2, which contains two tandemly arranged closely related genes (AtM10 and AtM17) coding for a new family of LEA proteins. The deduced proteins have a molecular mass of 11 and 29 kDa, respectively, are extremely hydrophilic except at their N-termini and share 70% amino acid (aa) identity. A 47 aa motif containing a 6-cysteine domain is present once in AtM10 and four times in AtM17. The short intergenic region, the identical position of the intron and the overall sequence homology suggest that these two genes evolved through a duplication event. This conclusion is supported by the presence of two homologous strictosidine synthase-like (pseudo)genes downstream from AtM17 and AtM10. Expression studies, using AtM10 and AtM17 cDNAs, revealed that both transcripts accumulate exclusively in seeds from late embryogenesis until two days after imbibition. Expression of both genes in young seedlings is repressed during ABA, salt or drought treatment, whereas a cold stress induces the expression of AtM17 only. In situ hybridization revealed that AtM10 transcripts are detected throughout the embryo while those of AtM17 are more localized to cotyledon cells.

Adaptation, Biological↗
PubMed1998

Production of human lactoferrin in transgenic tobacco plants.

Production and characterization of human lactoferrin (hLf) in transgenic tobacco is reported. We have engineered two constructs containing either the native signal peptide from human lactoferrin or the signal peptide from sweet potato sporamin fused to human lactoferrin encoding cDNA. N-terminal sequences of rhLf purified from tobacco were identical to Lf from human milk for both constructs. The tobacco rhLf presents a molecular mass closely identical to native protein. Overall sugar composition shows the presence of plant specific xylose while sialic acid is absent. Binding parameters of the recombinant molecule to both Jurkat lymphoblastic T-cells or HT29-18-C1 enterocytes are similar to those of human lactoferrin isolated from milk.

Amino Acid Sequence↗
PubMed1995

[Expression of recombinant human hemoglobin in plants].

Human utilization of recombinant proteins of therapeutical interest, as hemoglobin, implies that the transgenic host allows a low cost production of the active proteins with minimal risks of pathogen contamination. In this regard, the use of transgenic plants could be of great interest. In particular, the systems based on plants could be one of the most economical transgenic system, compared with the others, because biomass obtention in fields is not expensive.

Carbohydrate Sequence↗
PubMed1995

Longer episodes of community residential care reduce substance abuse patients' readmission rates.

OBJECTIVE: The study focuses on whether substance abuse patients who enter a community residential facility (CRF) after discharge from inpatient care obtain more outpatient mental health care and have lower readmission rates than comparable patients discharged directly to the community. METHOD: A national sample of substance abuse patients (N = 5,176; 99% men) referred to CRFs after inpatient substance abuse care is compared to a matched sample of patients (N = 5,176; 99% men) discharged to the community. RESULTS: Compared with controls, CRF patients were more likely to obtain outpatient mental health aftercare and obtained more intensive care. Patients with longer episodes of CRF care had lower 6-month and 1-year readmission rates than patients who dropped out of CRFs and than matched controls. These findings held for patients who had only alcohol diagnoses, patients who had drug diagnoses and patients who had psychiatric diagnoses in addition to their substance abuse disorders. Longer length of CRF care and more outpatient mental health care were significant predictors of lower readmission rates after other risk factors for readmission were controlled. CONCLUSIONS: Longer episodes of community residential care can contribute to better outcomes for substance abuse patients, in part by maintaining patients' involvement in outpatient mental health care. CRFs may play an important role in the continuum of substance abuse patients' care.

Activities of Daily Living↗
PubMed1993

Pregnancy and contraception use among urban Rwandan women after HIV testing and counseling.

OBJECTIVES: This study examined hormonal contraceptive use and pregnancy in urban Rwandan women, following human immunodeficiency virus (HIV) antibody testing and counseling. METHODS: A sample of 1458 childbearing urban Rwandan women aged 18 to 35 years was tested and followed for 2 years. RESULTS: At enrollment, 17% of 998 HIV-negative women and 11% of 460 HIV-positive women were pregnant, and 17% vs 23%, respectively, were using hormonal contraceptives. One year later, half of the HIV-positive and one third of the HIV-negative hormonal-contraceptive users had discontinued use. The 2-year incidence of pregnancy was 43% in HIV-positive and 58% in HIV-negative women. HIV-positive women with fewer than four children were more likely to become pregnant than those with four or more; this association persisted in multivariate analyses but was not noted among HIV-negative women. At the end of the study, over 40% of non-users said that they would use hormonal contraception if it was provided at the study clinic, but 40% of HIV-positive women desired more children. CONCLUSIONS: Research is needed to identify the practical and psychosocial obstacles to effective long-term contraception among HIV-positive women. HIV counseling programs must specifically address the issue of childbearing.

AIDS Serodiagnosis↗
PubMed1991

Heterozygosity in tetraploid potatoes revealed by rDNA polymorphism analysis of their dihaploid progenies: a contribution to chromosome assignment.

Restriction map and organization of rDNA was inferred from analysis of dihaploid progenies of two tetraploid genotypes of cultivated potato. Each tetraploid genotype was characterized by a specific distribution of different types of rDNA repetition units on their four homologous chromosomes II. The genotypes were heterozygous and differed by the kind of units carried by each chromosome II. Models for the generation of the observed organization are discussed and supported by first cloning studies.

Blotting, Southern↗
PubMedDate not supplied

Identification of a glutathione conjugate of cambendazole formed in the presence of liver microsomes.

The incubation of multiply labeled (2H, 3H, 13C, 14C) cambendazole and glutathione with hepatic microsomes from phenobarbital-dosed hamsters results in the formation of polar metabolites. The major metabolite has been characterized by a variety of isotopic, spectrometric, chromatographic, and degradative/synthetic techniques as a glutathione conjugate of cambendazole in which substitution is on the 4-position of the benzimidazole nucleus. The same metabolite is produced by hepatic microsomes from the rat.

Animals↗