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Biomedical subjects

L Barone

Publications and source records attributed to L Barone.

At least 19 recordsLinked to original sources
PubMed2003

Assessing the older person: is the MNA a more appropriate nutritional assessment tool than the SGA?

OBJECTIVES: A study was undertaken to determine which nutritional assessment tool would be better in assessing changes in nutritional status over time in hospitalised older patients. The two tools used were the Mini Nutritional Assessment (MNA) and the Subjective Global Assessment (SGA). DESIGN: Single blind, prospective study conducted over a 60-day period. SETTING: Five regional hospitals within Southern New South Wales, Australia. SUBJECTS: There were 43 patients at the commencement of the study, then 28 patients at day 30 and 20 patients at day 60. METHODS: All patients over 65 years of age admitted to the five hospitals during May 2001 were eligible. The only exclusions were those patients admitted to palliative care or with severe dementia. Two dietitians saw each patient. Each dietitian assessed the patient using his or her assigned nutritional assessment tool either the SGA or the MNA. All dietitians were randomly assigned the tool at the commencement of the study. They were familiarised with the use of the tool by participating in a workshop prior to the start of the study. RESULT: The MNA was able to detect greater numbers of malnourished subjects when compared to the SGA. This finding was consistent across Day 0, 30 and 60 and statistically significant (p<0.05) at all time periods. CONCLUSIONS: This study has shown the MNA to be a more appropriate nutrition assessment tool for older patients when compared to the SGA. The MNA is better able to identify severely malnourished patients. This study illustrated the potential use of the MNA as an ongoing monitor of nutritional status and hence a measure of the impact of nutrition intervention.

Aged↗
PubMed2000

Effects of infectious hematopoietic necrosis virus and infectious pancreatic necrosis virus infection on hematopoietic precursors of the zebrafish.

The zebrafish Danio rerio is a new model system for studying the genetics of hematopoiesis. To define naturally occurring viruses which could infect and replicate within hematopoietic precursors of the zebrafish, infectious hematopoietic necrosis virus (IHNV) and infectious pancreatic necrosis virus (IPNV) were studied. Infection of whole fish with viral supernatants demonstrated infectious replicants for both viruses, indicating that the virus host range includes the zebrafish. In other species, infection with these viruses leads to prominent hematopoietic necrosis of the head kidney, the major site of adult hematopoiesis. We detected a transient toxicity of the virus to hematopoietic precursors and terminally differentiated red cells after viral infections. The kinetics of hematopoietic defects between IHNV and IPNV infection differed; fish infected with either virus, however, recovered by 6 days postinfection. In contrast to other fish infected with the virus, hematocrit did not change appreciably during this time. These studies are the first to demonstrate IHNV and IPNV infection of the zebrafish and reveal the potential for use of such viruses for gene transfer experiments to infect zebrafish hematopoietic cells.

Animals↗
PubMed1998

Amplification of the ATP-binding cassette 2 transporter gene is functionally linked with enhanced efflux of estramustine in ovarian carcinoma cells.

An estramustine-resistant human ovarian carcinoma cell line, SKEM, was generated to explore resistance mechanisms associated with this agent. Cytogenetic analysis revealed that SKEM cells have a homogeneously staining region (hsr) at chromosome 9q34. Microdissection of the hsr, followed by fluorescence in situ hybridization to SKEM and normal metaphase spreads, confirmed that the amplified region was derived from sequences from 9q34. In situ hybridization with a probe specific for ABC2, a gene located at 9q34 that encodes an ATP-binding cassette 2 (ABC2) transporter, indicated that this gene is amplified approximately 6-fold in the estramustine-resistant cells. Southern analysis confirmed that ABC2 was amplified in SKEM, and Northern analysis indicated that the ABC2 transcript was overexpressed approximately 5-fold. The ABC1 gene located at 9q22-31 was not amplified in the resistant cells, and mRNA levels of several other ABC transporter genes were unaltered. Consistent with the concept that increased ABC2 expression contributes to the resistant phenotype, we observed that the rate of efflux of dansylated estramustine was increased in SKEM compared with control cells. In addition, antisense treatment directed toward ABC2 mRNA sensitized the resistant cells to estramustine. Together, these results suggest that amplification and overexpression of ABC2 contributes to estramustine resistance and provides the first indication of a potential cellular function for this product.

ATP-Binding Cassette Transporters↗
PubMed1996

Healing of chondral and osteochondral defects in a canine model: the role of cultured chondrocytes in regeneration of articular cartilage.

In this study a canine model was developed to investigate the nature of early healing responses to both chondral and osteochondral defects and to evaluate the tissue regenerative capacity of cultured autologous chondrocytes in chondral defects. The healing response to surgically created chondral defects was minor, with little cellular infiltration. In contrast, osteochondral defects exhibited a rapid cellular response, resulting ultimately in the formation of fibrous tissue. The lack of significant cellular activity in chondral defects suggests that an evaluation of the capacity of cultured autologous chondrocytes to regenerate articular cartilage is best studied in chondral defects using the canine model. When dedifferentiated cultured articular chondrocytes were implanted into chondral defects, islands of type II collagen staining were demonstrated in the regenerative tissue within 6 weeks. The relatively early expression of cartilage specific markers by the implanted chondrocytes, coupled with the inability of untreated chondral defects to repair or regenerate, demonstrates the utility of the canine model in evaluating novel materials for cartilage repair and regeneration.

Animals↗
PubMed1996

Glutathione-associated enzymes in the human cell lines of the National Cancer Institute Drug Screening Program.

The steady state expression of glutathione S-transferases (GSTs) at both the protein and mRNA level is reported for the 60 tumor cell lines that are used for the National Cancer Institute Drug Screening Program. Individual GST isozymes were separated, identified, and quantified (with reverse-phase calibration curves) through a novel high performance liquid chromatographic procedure. GSTP1 was the predominant isozyme and was found at quantifiable levels in all but two of the cell lines. This isozyme ranged from 0.03% to 2.7% of the total cytosolic protein. For the mu family, 90% of the lines had GSTM2, 68% had GSTM3, but only 28% were positive for the M1 phenotype. The M1 proportion is lower than would be expected from the standard M1 null phenotype for human populations. Isozymes of the alpha family were detected only at very low levels in 35% of the lines. Significant quantitative correlations among enzyme activity, total enzyme protein, and mRNA were shown for GSTP1. However, such relationships were not apparent for the mu or alpha families. Levels of glutathione (GSH), and the transcript levels of other enzymes involved in GSH homeostasis were determined. gamma-Glutamyl cysteine synthetase (gamma-GCS) was present in all cell lines, but did not correlate with levels of intracellular GSH. Glyoxalase-I and gamma-glutamyl transpeptidase, both involved in GSH salvage, were found in 100% and 70% of the cell lines, respectively. Using a pattern-matching computer program, COMPARE, we compared and correlated the arrays of mRNA and protein levels with the pattern of chemosensitivity or chemoresistance of the 60 cell lines with 175 agents constituting a standard agent database. This database is composed of compounds to which a putative mechanism of action has been assigned. Although Pearson correlation coefficients relating the target and drug patterns were generally modest, when the patterns for the enzyme protein and mRNA levels for GST pi were correlated to drug sensitivity patterns, the list of 30 agents most closely matching (for which P < 0.05) was enriched with alkylating agents. gamma-GCS also showed an enrichment of alkylating agents in the COMPARE correlations, indicating that high levels of gamma-GCS may be an important determinant of resistance. In contrast, none of the other enzymes or GSH had patterns of expression that resulted in an obvious correlation to the sensitivity or resistance of alkylating agents.

Antineoplastic Agents↗
PubMed1992

Combined antimicrotubule activity of estramustine and taxol in human prostatic carcinoma cell lines.

Estramustine (EM) and taxol, two antimicrotubule agents with distinct and apparently opposing mechanisms of action, were found to be effective in combination in the preclinical treatment of EM-resistant and sensitive, wild-type human prostatic carcinoma cell lines. Estramustine combined with 1 nM taxol (concentration 100-fold less than that measured in plasma of patients treated with taxol) produced greater than additive effects on the inhibition of cell survival of both wild-type and EM-resistant cells. When taxol was used with another microtubule-destabilizing drug, vinblastine, no significantly increased cytotoxicity was observed. Other effects on wild-type and EM-resistant cells produced by the combination of EM and taxol included (a) an increased proportion of the cells in the S phase of the cell cycle; (b) no mitotic block; and (c) an increase in the percentage of micronucleated cells from a control value of less than 1% to greater than 20% after drug treatment. Immunofluorescent microscopic analysis of the effect of this drug combination on the mitotic spindle apparatus revealed specific examples of aberrant mitotic figures, including multiple asters, cells with two distinct spindles, and tripolar spindles able to traverse mitosis and complete cytokinesis. These data provide supportive preclinical evidence for the potential development of an EM/taxol combination clinical regimen either for prostate or other cancers.

Alkaloids↗
PubMed1991

Assessment of HIV status using the polymerase chain reaction in antibody-positive patients and high-risk antibody-negative haemophiliacs.

The polymerase chain reaction (PCR) was used to identify the presence of DNA sequences homologous to HIV-1 in the buffy-coat leukocytes of antibody-positive and antibody-negative individuals in a haemophiliac population. The presence of HIV sequences was demonstrated in all of the antibody-positive haemophiliacs with the exception of one patient who was repeatedly negative. None of the seronegative haemophiliacs gave an overall positive result, although there were clear differences between this population and the negative controls who were examined. We conclude that, in our hands, PCR represents a reliable test which represents a useful diagnostic advance in HIV medicine.

Base Sequence↗