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Biomedical subjects

M Vitale

Publications and source records attributed to M Vitale.

At least 199 records · Page 11Linked to original sources
PubMed1987

Flow cytometric analysis of isolated rat liver nuclei during growth.

The development of hepatocyte polyploidy in rats aged up to 4 months was analyzed by flow cytometry using both scatter and fluorescent parameters to distinguish DNA diploid and DNA tetraploid populations and to discriminate between parenchymal and non-parenchymal compartments. The precise origin of each class of nuclei was assessed in whole liver homogenate using purified hepatocytes, obtained by liver perfusion followed by separation on Percoll gradient, and identifying the peaks corresponding to parenchymal nuclei. The results indicate that preparative procedures involving homogenization of the rat liver tissue caused loss of the DNA octaploid population. Data on the relative proportion of the different DNA ploidy elements during rat liver development, which are in good agreement with those observed by cell analysis by means of microspectrophotometry, indicate the usefulness of flow cytometry as a choice method for the analysis of ploidy distribution.

Animals↗
PubMed1987

Increased number of circulating Leu 11+ (CD 16) large granular lymphocytes and decreased NK activity during human ageing.

The phenotype and functional activity of circulating T and natural killer (NK) cells was investigated in a group of selected normal elderly donors in comparison with a group of normal young individuals. Old subjects exhibit a decline in circulating T cells and an impaired response to mitogens (Con A, PHA) associated with a relative increase in cells reacting with Leu 7 and Leu 11a monoclonal antibodies, directed against large granular lymphocytes with NK activity. The rise in circulating NK cells observed in the elderly was not associated with a concomitant increase in NK cytolytic activity against K 562 tumour cells, and time course kinetics of the cytotoxic reaction was similar to that observed in young subjects. When a greater than 95% pure population of Leu 11a+ cells from old individuals was sorted by flow cytometry and their functional cytotoxic activity examined, a significant decrease in NK cytotoxicity was detected. The target cell binding capacity of effector cells, morphologically evaluated at single cell level, did not differ in old and young subjects, even though bound cells from young donors have a higher lytic capacity. These data show that an increase in circulating NK granular lymphocytes occurs during human ageing, but suggest that in old subjects only a subset of NK cells is active in order to maintain a functional response similar to that observed in the young.

Adult↗
PubMed1986

A sandwich enzyme immunoassay for wheat gliadin.

A sandwich double antibody solid-phase enzyme immunoassay (EIA) that can detect and quantitate gliadin is described. Quantitative analysis could be carried out in the range of 5-400 ng/ml and the assay was more sensitive than inhibition EIA. Gliadin possessed weak cross-reactivity with oats, maize and rice prolamines. In the presence of anti-gliadin antibody (serum from a patient with active coeliac disease) gliadin could not be detected, but the sensitivity of the assay was restored by heat treatment of the serum. This EIA can therefore be employed to assess the gliadin content of biological fluids where specific antibody may coexist.

Antibody Specificity↗
PubMed1986

Changes in nucleosome structure and histone H3 accessibility. Iodoacetamidofluorescein labelling after treatment with phosphatidylserine vesicles.

The accessibility of the sulfhydryl-specific dye 6-iodoacetamidofluorescein (IAF) to H3 histone has been studied in isolated rat liver nuclei and mononucleosomal core particles after treatment with phosphatidylserine (PS) multilamellar vesicles (MLV). In isolated nuclei, despite the enhancement of total RNA synthesis and the massive chromatin decondensation produced by liposomes, the amount of histone H3 which can be labelled with the dye remains essentially the same in PS-treated as in control nuclei. However, when mononucleosomal core particles, treated with PS vesicles, are reacted with IAF, H3 becomes derivatized by the dye, while controls do not. These data provide additional evidence that the metabolic and structural changes observed in isolated nuclei treated with PS MLV, are due mainly to the reported removal of histone H1. Moreover, the experiments reported confirm the usefulness of IAF in studying the changes of nucleosome organization, since PS is able to affect the nucleosomal core configuration in isolated nucleosome particles, derivatizing the buried cysteine groups of H3 histone.

Animals↗
PubMed1986

In vitro activity of alpha, beta, gamma human interferons and Aspergillus terreus mycotoxins on cell proliferation.

The in vitro effect of different doses of alpha, beta and gamma human interferons and their interaction on the proliferation rate of human erythroleukemic cell line (K-562) and other cell lines has been evaluated. The results show that the stronger activity is exerted by beta HIF in comparison with alpha HIF. The action is selective and species-specific. beta HIF never elicited an "enhancing" effect on cell proliferation; on the contrary this phenomenon has been observed to occur with alpha and gamma HIF. In our cell system, the interaction between beta and gamma HIF gave a synergistic effect; on the contrary, no interaction has been observed to take place when beta HIF and directly cytotoxic mycotoxins extracted from A. terreus are associated.

Cell Division↗
PubMed1986

In vitro antimicrobial activity in comparison with tonsillar tissue penetration of mezlocillin.

The aim of this study was to determine the role of mezlocillin, a new acylureidopenicillin, in otorhinolaryngology. One hundred and forty-four bacterial strains were isolated from 100 patients suffering from infections of the oropharyngeal tract. Among the isolates only 10 (6.9%) resulted in being mezlocillin-resistant by the agar diffusion method. Minimum inhibitory and minimum bactericidal concentrations were also determined. Pharmacokinetic parameters e.g., diffusion in tonsillar tissue and serum concentrations, were studied. Mean mezlocillin tonsillar levels of 3.5 micrograms/g and 1.8 micrograms/g and serum concentrations of 60.2 micrograms/ml and 10.6 micrograms/ml, 1 h and 4 h respectively after administration, were found.

Adolescent↗
PubMed1984

Rho-dependence of the terminator active at the end of the I region of transcription of bacteriophage f1.

Infection of rho- Escherichia coli cells with deletion mutant PII of bacteriophage f1 results in a miniphage RNA population composed of transcripts longer than those synthesized in the infection of rho+ cells. This indicates a Rho dependence of the terminator active at the end of the I region of transcription of bacteriophage f1. An estimate of the length of a transcript, which represents a good fraction of the RNA that passes beyond the terminator, indicates that the hairpin structure where synthesis of complementary strand DNA initiates also acts as a fairly efficient Rho-independent terminator.

Base Sequence↗
PubMed1984

Transcription in bacteriophage f1-infected Escherichia coli: RNA synthesized on DNA of deletion mutant PII shows the existence of a two-site terminator.

Two different transcripts are synthesized on the DNA of deletion mutant PII of bacteriophage f1 in E. coli cells infected with this miniphage. Both RNA species appear to be primary transcripts and differ by about 100 nucleotides at their 3'OH end. Mapping of these molecules on the miniphage genome suggests that a two-site terminator is active at the end of the I region of transcription of bacteriophage f1.

Base Sequence↗
PubMed1984

Postextrasystolic potentiation in isolated rat myocardium: dependence on resting muscle length.

The degree and decay of postextrasystolic potentiation were studied in isolated rat papillary muscle at Lmax, the length at which developed force was maximum, and at shorter lengths. Potentiation curves were constructed relating the degree of potentiation with the time interval between any given extrasystole and the last steady-state beat. At all stimulation rates tested (ranging from 3 to 60/min), potentiation curves were found to be dependent on muscle length: at any interval the degree of potentiation increased progressively with decreasing initial muscle length. At all lengths and stimulation frequencies tested, the decay of potentiation was a function of the number of beats following the extrasystole. This relationship could be fitted by a single exponential equation. The exponential constant of the decay was significantly smaller at Lmax than at shorter lengths. These results suggest that muscle length affects more than one step of the E-C coupling processes.

Animals↗
PubMed1984

[A case of chondromatous hamartoma of the lung in 2 places].

A case of chondromatous hamartoma of the lung, with a double localization (right upper and middle lobes observed in a 62-year old man and treated by bilobectomy is presented. A short review of the pertinent literature is also reported.

Hamartoma↗
PubMedDate not supplied

A region upstream of the human delta-globin gene shows a stage-specific interaction with globin promoters in erythroid cell lines.

We previously showed that the 651-bp DNA fragment, located 3 kb upstream from the human delta-globin gene (fragment F5), is able to inhibit adult, not fetal, globin promoter in mouse erythroleukemia cell lines (MEL) expressing adult globin genes. Here we show in transient analysis that fragment F5 has a strong inhibitory effect on fetal gamma-globin promoter in human erythroleukemia cell lines (HEL) expressing fetal globin genes. Since the beta-promoter constructs were poorly expressed in fetal cells, new plasmids containing an HPFH promoter (Ggamma(-175), T to C), which is strongly expressed in both fetal and adult cell lines, were made. Here we report that fragment F5 in HEL cells has a strong inhibitory effect on wild-type gamma-promoter only; no effect was evident on gamma(-175)-promoter in either MEL or HEL cell lines. Altogether these results show a stage-specific interaction between fragment F5 and globin promoters during development. We also report the presence of several bindings for erythroid GATA family factors by electrophoretic mobility shift assay, using nuclear extracts from erythroid cell lines.

Animals↗
PubMedDate not supplied

Severe itching in the patient with burns.

After discharge, the patient with burns is often plagued with persistent, unrelenting itching. The purpose of this study was to document the incidence and severity of itching in discharged patients with burns, to determine factors that may help in prediction of the problem, and to study the effectiveness of Benadryl (Parke-Davis, Morris Plains N.J.), Atarax (Roerig Div. of Pfizer Inc., New York, N.Y.) and Polyhist Forte (Mikart Inc., Atlanta, Ga.) in relieving the symptom. All adult patients who were discharged to our outpatient clinic were entered into this prospective study. Patients were started on one of the three agents, and agents were changed monthly in a randomized fashion. Severity of itching was determined by a visual linear analogue scale. The study population had a mean age of 35.9 +/- 12.8 years, and a mean burn size of 19.1% +/- 15.3% total body surface area. Eighty-seven percent of discharged patients complained of itching. The average severity of the problem was 7.6 +/- 1.9. A significant difference (p less than 0.05) among groups was found when the population was analyzed for size of burn and duration of time to wound closure. Symptoms varied with anatomic area burned. One hundred percent of patients with leg burns and 70% of those with arm burns complained of itching. Facial burns did not cause itching in any of the patients. The agents that were tested produced complete relief in only 20% of patients, partial relief in 60%, and no relief in 20%. There were no differences in response to the three agents tested. All three of the drugs that were tested had similar onset of action.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Analysis of HLA specificity of human monoclonal antibodies by cytofluorimetry and cell ELISA.

In this study we report on the characterization of cytotoxic human monoclonal antibodies (HmAb) detecting polymorphic HLA class II specificities using cytofluorimetric analysis in combination with micro cell ELISA. In both techniques, five anti-HLA HmAb were tested against HLA-transfected murine L cells as target cells and the bound antibody was detected, either by cytofluorimetry or by cell ELISA reader, after addition of fluoresceinated or peroxidase-conjugated anti-human IgG+IgM antibodies, respectively. The results demonstrate that HmAb directed against HLA-DR, -DQ and -DP molecules can be efficiently discriminated by cytofluorimetry and cell ELISA, which appear to be highly sensitive and perfectly comparable to the standard cytotoxicity assay.

Animals↗
PubMedDate not supplied

[Quality of life in hemodialyis patients: the effect of educational status].

INTRODUCTION: Hemodialysis has a major influence on the quality of life of chronic renal failure patients. Great attention is currently paid to the development of supporting programmes for this patient group. Aim of this study was to evaluate the quality of life in maintenance dialysis and to research the influence of various factors related to treatment and ESRD on quality of life, taking into account also the level of school instruction. PATIENTS AND METHODS: Reduced functional abilities, as measured by the Sickness Impact Profile (SIP), and Functional Living Test (FLT), derived by Karnofsky Activity Scale were assessed; Hospital Anxiety and Depression Scale (HAD) and semistructured interviews, including a clinical grading of symptoms were considered vs. age, duration of dialysis, level of school instruction. The study was performed with 40 hemodialysis patients, aged 57.4 +/- 14.9 years (range 22-79), treated since at least three years. RESULTS: Significant (P < 0.05) independent correlates with higher SIP scores (greater disability) and Functional Living Test were lower educational level, and the score of Hospital Anxiety and Depression Scale (HAD). No correlation was found for any of the three scales vs. age and vs. dialytic age; no gender difference was observed. DISCUSSION: A greater care in considering Quality of Life questionnaires is warranted, especially for the severe interference of instruction level of patients on results. QALY (Quality Adjusted Life Years), used as a tool for decision-making in clinical and political subsets, can include critical bias that invalidate conclusion.

Adult↗
PubMedDate not supplied

[Laparoscopic cholecystectomy. Our experience].

BACKGROUND: The many advantages and extreme versatility made laparoscopic cholecystectomy (L.C.) the gold standard for symptomatic cholelithiasis. The aim of this research is a retrospective analysis of personal experience with laparoscopic cholecystectomy in a peripheral hospital compared with the literature on the subject. METHODS: Since June 1982, a total of 989 L.C. have been performed. The patients were: 691 (68.6%) women and 298 (29.4%) men with a mean age of 56 years (range 17-84). The indications were: 791 symptomatic cholelithiasis, 142 chronic cholecystitis, 45 empyema-hydrops and 11 adenomyomatosis. RESULTS: No postoperative death have been observed and the conversion rate was of 24 cases (2.3%). The main complications were 3 cases of injury of the biliary tract and 2 cases of postoperative bleeding (1 from cystic artery and 1 from the umbilical wound). Minor complications observed were 12 cases (1.2%) of infections of the umbilical wound and 3 cases of umbilical hernia (0.3%). The elevation of stasis index was observed in 3 cases which solved spontaneously. The length of stay was 2 days in 957 cases (97%), 8 days in 24 cases and 4-5 days in 8 (0.7%). CONCLUSIONS: No major trochar's lesions occurred, contrary to the percentages quoted in the literature (0.02%-0.9%). The selective use of the open technique and of the multiuse conic section trocar in the "closed" technique is suggested. The 3 cases of bile duct lesions did not occur during the training period, contrary to what quoted in the literature. In personal opinion, a careful surgical technique with a good Calot's triangle preparation, is necessary to prevent these inconveniences. Parietal complications (umbilical wound infections and laparocele) even if lesser than in the laparotomy technique, can be reduced by using the endobag and suturing the abdominal fascia of the 10 mm trocars. Moreover, the use of a systematic subhepatic drainage during the first 24 postoperative hours is suggested, since it can be useful to reveal possible bleeding.

Adolescent↗
PubMedDate not supplied

Natural killer lymphocytes: "null cells" no more.

Natural Killer (NK) lymphocytes were initially described as potent effector cells that, unlike T lymphocytes, were able to kill targets in the absence of a priori stimulation and without specific recognition mechanisms. Over the past ten years however, it has been clearly demonstrated that NK cell function is regulated by a number of surface receptors that bind specific ligands expressed by target cells. Some of these receptors display inhibitory functions and recognize MHC class I molecules expressed by normal autologous cells that, as a consequence, are spared from indiscriminate NK-mediated killing. Other receptors are involved in NK cell activation against allogeneic cells or cells that, upon viral infection or tumor transformation, down-regulate MHC Class I expression. Altogether these data provide important advances toward the understanding of the complexity of the molecular mechanisms that regulate NK-mediated functions.

Cytotoxicity, Immunologic↗