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PubMed2004

Biosensors for determination of total and natural antioxidant capacity of red and white wines: comparison with other spectrophotometric and fluorimetric methods.

Research was carried out to experimentally evaluate the antioxidant capacity of several red and white wines using a superoxide dismutase (SOD) biosensor recently developed by the present authors. Measurements were performed by comparing the biosensor response to increasing concentration of the superoxide radical produced in solution by the xanthine/xanthine oxidase system, both in the presence and absence of the test sample.The results were compared with those of two traditional spectrophotometric methods and of a spectrofluorimetric method described in literature.Lastly, also the polyphenol, sulfite and ascorbic acid contents of the different wine samples examined were measured using a tyrosinase biosensor, a sulfite oxidase biosensor and an ascorbate oxidase biosensor, respectively.

Antioxidants↗
PubMed1984

Sigmoidocystoplasty to augment bladder capacity.

Sigmoidocystoplasty with subtotal cystectomy was carried out in 14 patients with severe, symptomatic contracture of the bladder, refractory to other modes of therapy. Eight patients had excellent results, four showed improvement, two showed no improvement and required supravesical diversion. Indications for the procedures, complications and over-all results are discussed, with emphasis on our surgical technique. The possible advantages of sigmoidocystoplasty over ileal and ileocecal cystoplasty are noted.

Adolescent↗
PubMed1996

Potential transforming-ability by internal deletion of the bovine c-myb gene.

Two kinds of bovine c-Myb, the 75 kDa full-length (FL) c-Myb from the thymic type of sporadic bovine lymphosarcoma (SBL) cells, and 65 kDa deleted (DEL) c-Myb, which is an internally deleted form (85 amino acids corresponding to the negative regulatory domain) from calf-type SBL were found. To investigate the relationship between internal deletion and transforming capacity, we constructed retroviral vectors carrying cDNA that encoded either FL- or DEL-Myb protein, and transfected them to mouse fetal liver cells. In spite of the high trans-activating capacity of DELMyb, DELMyb and FLMyb showed no significant difference in oncogenic capability by measurement of colony formation in soft agar or in methylcellulose medium. Thus, the internal deletion of the c-myb gene is competent for transactivation but not directly relevant to transformation of mouse hemopoietic cells.

3T3 Cells↗
PubMedDate not supplied

[Cooperative analysis of measurements of capacity and optical parameters of bilayer lipid membranes].

On the model of rough bilayer lipid membrane (BLM) a cooperative analysis was carried out of measurements of its capacity and of reflective ability and transmission in the optical range of the wave lengths. A correct estimation of roughness of BLM containing squalene was given, roughness parameters initiated under BLM electrostriction were estimated. Electrostriction mechanism of rough BLM was considered. It has been shown that discrepancies while measuring the elasticity modulus E perpendicular to bilayer plane by capacitive and optical methods are due to some peculiarities of the latter, which in fact measures another elasticity modulus E (at two-sided widening of the bilayer in its plane). The optical and capacitive methods give additional information concerning BLM deformations at electrostriction.

Electrochemistry↗
PubMed1989

Measurement of diffusing capacity in pulmonary embolism.

Pulmonary function tests were carried out in 20 consecutive patients with pulmonary embolism (PE), diagnosed on the basis of a positive ventilation-perfusion lung scan carried out within 72 h of admission. Changes in forced expiratory volume in one second (FEV1), forced vital capacity (FVC) and arterial blood gas tensions were too variable to be helpful diagnostically. In contrast, transfer factor (diffusing capacity) of the lung (TLCO) was significantly reduced in all cases and, in spite of a period of anticoagulation, tended to remain subnormal during a follow-up period of up to 3 years. Lung scans, however, tended to return to normal within 3 months of the incident. Thus, a reduction of TLCO to below 75% of the predicted normal was found in all cases with abnormal lung scans and such measurements provide a useful and simple screening test for PE; a normal TLCO would effectively exclude such a diagnosis. The failure of TLCO to return to normal in the majority of cases suggests persistence of the underlying physiological defect, in spite of normalization of symptoms and lung scans following anticoagulation.

Adult↗
PubMed1983

Decrease of learning capacity in offspring with increasing paternal age in the rat.

The same 15 male Wistar rats at the ages of 2.5, 6, 10, 14, 18, and 22 months were successively randomly mated with 2.5-month-old females. In a separate experiment, 15 male Wistar rats at the age of 2.5 months and 15 at the age of 23 months were simultaneously randomly mated with 2.5-month-old females. Offspring were evaluated in regard to the mean number per litter, sex ratio, frequency of gross external malformations, growth pattern, and mortality in the first 13 weeks of life and reproductive capacity at 13 weeks of age. They were also evaluated for spontaneous activity and emotionality with an open field test and for learning capacity with an avoidance conditioning test, both carried out between 10 and 13 weeks of age. Only learning capacity of the offspring, expressed in percentage of success for male or female, decreased consistently and significantly as the father's age increased. But females did not seem to be affected in the same way as males. The genetic implications are briefly discussed.

Aging↗
PubMed1997

Uptake of plasmid RSV DNA by frog and mouse spermatozoa.

Xenopus laevis spermatozoa and mouse epididymal spermatozoa were compared in their ability to bind plasmid DNA. Spermatozoa of both species are endowed with a very similar binding capacity for plasmid pAPrC DNA carrying the complete Rous sarcoma virus (RSV) DNA. Our experiments failed to detect any substantial differences between both types of sperm cells in the kinetics of DNA binding, maximum DNA binding capacity, effect of various ions, metabolic inhibitors and substrates on DNA binding, etc. Each X. laevis and mouse sperm cell associates, on an average, with about 50 and 45 molecules, respectively, of the plasmid DNA in a DNase resistant form, if spermatozoa were exposed to the DNA at a concentration of 0.5 microgram/5 x 10(6) sperm cells. The uptake of the DNA by both types of sperm cells is strongly inhibited by heparin. The 37-kDa factor IF-1 shown by Zani et al. (1995) to specifically block DNA binding to mouse sperm cells inhibited the interaction between pAPrC DNA and frog spermatozoa with a similar intensity.

Animals↗
PubMed2001

Laser revascularisation.

Patients who present with angina pectoris due to underlying coronary artery disease which is not controlled by medical therapy, and who have disease which is not amenable to conventional forms of revascularisation, present an increasing clinical problem. Laser techniques have been introduced to improve myocardial perfusion in this group of patients. The surgical technique of transmyocardial laser revascularisation has been evaluated in this patient population. Generally, there has been a good symptomatic response in terms of improvement in angina, and in some studies an increase in exercise capacity. The technique, however, does carry significant morbidity and mortality. More recently, a catheter-based technique has been introduced--percutaneous myocardial laser revascularisation. This technique seems to improve symptoms of angina, produce an increase in exercise capacity, with a much more favourable procedural risk profile.

Angina Pectoris↗
PubMed2003

G protein-dependent CCR5 signaling is not required for efficient infection of primary T lymphocytes and macrophages by R5 human immunodeficiency virus type 1 isolates.

The requirement of human immunodeficiency virus (HIV)-induced CCR5 activation for infection by R5 HIV type 1 (HIV-1) strains remains controversial. Ectopic CCR5 expression in CD4(+)-transformed cells or pharmacological inhibition of G(alpha)i proteins coupled to CCR5 left unsolved whether CCR5-dependent cell activation is necessary for the HIV life cycle. In this study, we investigated the role played by HIV-induced CCR5-dependent cell signaling during infection of primary CD4-expressing leukocytes. Using lentiviral vectors, we restored CCR5 expression in T lymphocytes and macrophages from individuals carrying the homozygous 32-bp deletion of the CCR5 gene (ccr5 Delta32/Delta32). Expression of wild-type (wt) CCR5 in ccr5 Delta32/Delta32 cells permitted infection by R5 HIV isolates. We assessed the capacity of a CCR5 derivative carrying a mutated DRY motif (CCR5-R126N) in the second intracellular loop to work as an HIV-1 coreceptor. The R126N mutation is known to disable G protein coupling and agonist-induced signal transduction through CCR5 and other G protein-coupled receptors. Despite its inability to promote either intracellular calcium mobilization or cell chemotaxis, the inactive CCR5-R126N mutant provided full coreceptor function to several R5 HIV-1 isolates in primary cells as efficiently as wt CCR5. We conclude that in a primary, CCR5-reconstituted CD4(+) cell environment, G protein signaling is dispensable for R5 HIV-1 isolates to actively infect primary CD4(+) T lymphocytes or macrophages.

CD4-Positive T-Lymphocytes↗
PubMed1978

Relationships between IgE antibody production and other immune responses. II. Effect of thymectomy at various times after birth.

Mice were subjected to thymectomy at various times after birth and immunized with ovalbumin in aluminum hydroxide gel at 4 or 8 weeks of age. The capacities to produce IgE, IgM and IgG antibodies were abolished by thymectomy carried out within 48 h after birth. The capacity to produce IgE antibody was not affected by thymectomy at 7 days or later, whereas the capacities to produce IgM and IgG antibodies were reduced by thymectomy carried out at 4 weeks of age.

Animals↗
PubMed1995

Sequential changes in serum iron and ferritin in patients undergoing high-dose chemotherapy and radiation with autologous bone marrow transplantation: possible implications for treatment related toxicity.

In an effort to define the pattern of iron flux during high-dose chemotherapy or chemo/radiotherapy, we prospectively measured serum iron, iron binding capacity, and ferritin in patients undergoing autologous bone marrow transplantation for various malignancies. Sequential measurement of serum iron from days -7 to +12 was carried out in 88 evaluable patients, and simultaneous measurement of iron, ferritin, and total iron binding capacity was carried out in 32 patients. We found that there was a predictable rise in serum iron on day -2 or -3, and that this was accompanied by an increase in the saturation of transferrin. In addition, there was a similar increase in serum ferritin levels, which peaked by day +2. We suggest that the timing of this change in serum iron and saturation of transferrin may be important in mediating endothelial cell damage and, hence, organ toxicity in the setting of AuBMT. Based on these findings, we suggest that large clinical studies could be a source of patient samples to measure surrogate endpoints such as lipid peroxidation products (malondialdehyde or isoprostanes), or protein oxidation products following high-dose chemo/radiotherapy to determine the role of iron in cellular injury. It is possible that pharmacological manipulations to reduce free radical production or to chelate iron during the days prior to bone marrow reinfusion might help to reduce tissue injury in the setting of bone marrow transplantation.

Adolescent↗
PubMed1997

Ethiodized oil emulsions in hepatic microcirculation: in vivo microscopy in animal models.

RATIONALE AND OBJECTIVES: The authors' purpose was to define the stability and drug-carrying and drug-releasing capacity of ethiodized oil emulsions in the hepatic circulation. METHODS: Emulsions prepared in various ratios of a nonionic contrast material containing doxorubicin to ethiodized oil were injected into the hepatic arteries of normal and tumor-bearing livers in rats or mice. In vivo microscopy was used to observe the dynamic distribution of the emulsions in the hepatic circulation. RESULTS: A solution of less water mixed with more oil formed water-in-oil (w/o) phase emulsions, whereas oil with more water formed oil-in-water (o/w) emulsions. The oil in the emulsions carried the water in the blood circulation. The w/o emulsions exhibited significantly higher carriage capacity and longer release time for the drug solution than did the o/w emulsions (P < .01). CONCLUSION: The delivery of w/o emulsions is superior to that of o/w emulsions. Further studies about preparation methods and delivery capability of emulsions in the liver are warranted.

Animals↗
PubMed1992

Heterogeneity of Na,K-ATPase from kidney.

Na,K-ATPase was purified from pig and mink kidney. Enzyme batches of high specific activity apparently contained only alpha- and beta-peptides, judging from the SDS-gel-electrophoretic pattern. Careful determinations of the ouabain-binding capacity and binding kinetics were carried out. The question whether the functional unit is an alpha beta-protomer, a diprotomer or even a polymer was analysed from the binding stoichiometry and the binding pattern at nonsaturating ouabain concentrations. The binding capacity exceeded half of the theoretical maximum value for exclusively alpha beta-promoters. A half-of-the-sites reactivity of a diprotomer thus seems less likely, though nearly half of the protein is not accounted for in its absence. When ouabain binding took place in the presence of Na+, at least two binding components were noticed. Most probably the two components are not of equal size, thus excluding a co-operative diprotomer construction of the active ouabain-binding units. If the co-operativity model has to be abandoned, the phenomenon could be due to two or more isozymes exhibiting different Na(+)-affinities. Isoforms of the hydrolytic alpha-peptide were analysed by an ELISA technique and on blots of Na,K-ATPase peptides utilizing commercial isoform-specific antibodies. Though not absolutely specific, the individual antibodies were assumed to be monospecific with respect to the single isoforms of the alpha-peptide. In that case, data were consistent with a significant contribution of alpha 2- and alpha 3-isoforms (about 15%), in addition to the predominant alpha 1-isoform in kidney Na,K-ATPase.

Animals↗
PubMed2002

Nelfinavir-resistant, amprenavir-hypersusceptible strains of human immunodeficiency virus type 1 carrying an N88S mutation in protease have reduced infectivity, reduced replication capacity, and reduced fitness and process the Gag polyprotein precursor aberrantly.

The evolution of human immunodeficiency virus type 1 (HIV-1) strains with reduced susceptibility to protease inhibitors (PIs) is a major cause of PI treatment failure. A subset of subjects failing a therapy regimen containing the PI nelfinavir developed mutations at position 88 in the protease region. The N88S mutation occurring in some of these subjects induces amprenavir hypersusceptibility and a reduction of fitness and replication capacity. Here we demonstrate that substitutions L63P and V77I in protease, in combination, partially compensate for the loss of fitness, loss of replication capacity, loss of specific infectivity, and aberrant Gag processing induced by the N88S mutation. In addition, these mutations partially ablate amprenavir hypersusceptibility. Addition of mutation M46L to a strain harboring mutations L63P, V77I, and N88S resulted in a reduction of fitness and infectivity without changing Gag-processing efficiency, while amprenavir hypersusceptibility was further diminished. The ratio of reverse transcriptase activity to p24 protein was reduced in this strain compared to that in the other variants, suggesting that the M46L effect on fitness occurred through a mechanism different from a Gag-processing defect. We utilized these mutant strains to undertake a systematic comparison of indirect, single, cycle-based measures of fitness with direct, replication-based fitness assays and demonstrated that both yield consistent results. However, we observed that the magnitude of the fitness loss for one of the mutants varied depending on the assay used.

Carbamates↗
PubMed2002

Researching Aboriginal health: experience from a study of urban young people's health and well-being.

European colonisation had a devastating effect on the health and well-being of indigenous people in Australia. The history of Aboriginal health research has reflected the history of colonisation; research has understandably been viewed with distrust. The need for accurate statistics and improved understanding of health problems is clear, but obtaining them is not easy. In this paper we describe the first stage of a study of the health and well-being of urban young people that was initiated and carried out by the Victorian Aboriginal Health Service (VAHS), a community controlled organisation. This longitudinal study aims to describe the prevalence and incidence of a range of health problems, to explore their interrelated determinants, and to increase the capacity of the VAHS to carry out research. The process of planning and carrying out this study raised a number of interesting ethical, cultural and methodological issues. These issues include the establishment of an appropriate and properly constituted local ethics committee, the difficulty of obtaining a representative sample, the need for ongoing negotiation, attention to language, the use of a subject-generated identity code, and the need to recruit a wide range of peer interviewers. Achievements include a series of community reports of the findings, the establishment of a cohort of young people for a longitudinal study; a shift in attitudes toward research; a strengthened network of young Kooris; increased use of the health service by young people and the establishment of an after-hours clinic service and meeting place for young people. The aim of this analysis of our achievements and constraints is to assist others planning similar research, and to demonstrate the value for process and outcomes of research conducted under Aboriginal community control.

Adolescent↗
PubMed2005

Spirometer-dependence of vital capacity in ALS: validation of a portable device in 52 patients.

Since the evaluation of vital capacity (VC) needs to be carried out every three months in patients with amyotrophic lateral sclerosis (ALS), a portable spirometer would be of value in clinical practice. Over the follow-up of 52 ALS patients, we compared the values of slow vital capacity measured by two spirometers: a reference flow-metered spirometer based on a Hans-Rudolph pneumotachograph and a portable Venturi spirometer. The objectives were to analyse the overall concordance of the measurements from the two devices and determine a discordance cut-off. The correlation between measurements was high (r = 0.936) and significant (p<10(-20)). Bland and Altman analysis showed that the measurements were concordant at a statistical risk of 5%; nevertheless, on examination of the raw differences between the measurements, two sub-populations could be identified on either side of the 56% cut-off where the means of the differences were significantly different (p<0.0001). The 56% cut-off was also statistically significant in plotting differences against the coefficient of variations of the data pairs expressed as (100 x s/mean). The differences observed between the two spirometers could be explained by technical differences between the devices as well as by an increase in variability with progression of the disease. In conclusion, this study demonstrates that a portable spirometer can be used reliably at the bedside. For values of vital capacity below the discordance cut-off of 56%, vital capacity should be determined by operators trained in pulmonary function examinations.

Amyotrophic Lateral Sclerosis↗
PubMed1998

Temporary suppression of cell-mediated immunity in standardbred horses with decreased athletic capacity.

Eighty Standardbred horses, originating from 5 training campuses, with decreased athletic performance in association with symptoms such as intermittent fever and mild pharyngitis were examined. As control animals, 10 horses from a stable with normally performing horses were used. Virus isolation and clinico-chemical and serological tests were performed. Lymphocyte proliferation tests were carried out to evaluate the capacity of the cell-mediated immunity. In addition, a bioassay for equine type I interferon, as a marker for early viral infections, was established. No specific microbe could be linked to these symptoms, but there was a temporary suppression of the cell-mediated immunity, which might be explained by the serological evidence of an EHV-2 and/or rhinovirus infection.

Animals↗
PubMed1995

An osmolyte effect on the heat capacity change for protein folding.

We have carried out a differential scanning calorimetry study into the pH effect on the thermal denaturation of ribonuclease A at several concentrations of the osmolyte sarcosine. In order to properly analyze these data, we have elaborated the thermodynamic theory of the linkage between temperature, cosolvent, and pH effects. The denaturation heat capacity increases with sarcosine concentration. The effects of temperature and sarcosine concentration on the denaturation enthalpy and entropy values are well described by convergence equations, with convergence temperatures of around 100 degrees C for the enthalpy and around 112 degrees C for the entropy; we suggest that these effects might be related to a solvent-induced alteration of the apolar-group-hydration contribution to the folding thermodynamics. From our data, we estimate that about 70 extra molecules of water are thermodynamically bound upon ribonuclease denaturation in diluted aqueous solutions of sarcosine; this number is 6-9 times smaller than that predicted on the basis of the following two premises: (a) the osmolyte is strongly excluded from the surface of both the native and the denatured protein and (b) the denatured state is a fully solvated chain. We suggest that at least one of these two premises does not hold. We briefly comment on the potential use of cosolvent effects on thermal denaturation to evaluate the degree of hydration of denatured proteins (thus providing an independent measure of the consequence of their possible residual structure) and, also, on the possibility of finding substances that are more efficient protein stabilizers than known osmolytes are.

Animals↗