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Biomedical subjects

M Greco

Publications and source records attributed to M Greco.

At least 37 records · Page 2Linked to original sources
PubMed2001

Helium-Neon laser irradiation of hepatocytes can trigger increase of the mitochondrial membrane potential and can stimulate c-fos expression in a Ca2+-dependent manner.

BACKGROUND AND OBJECTIVE: To gain some insight into the photostimulation of isolated hepatocytes irradiated with Helium-Neon (He-Ne) laser light certain biochemical events were studied with respect to two mechanisms: i) the direct light dependent activation of certain biochemical events investigated in intact cells and isolated mitochondria, ii) the indirect stimulation of processes per se light independent. STUDY DESIGNS/MATERIALS AND METHODS: Irradiation of either isolated hepatocytes or isolated rat liver mitochondria was carried out with He-Ne laser (wavelength, 632.8 nm; fluence, 0.24 J cm-2; fluence rate, 12 mW cm-2). Changes in mitochondrial membrane potential in isolated hepatocytes were monitored using the cationic probe safranine. The c-fos expression was studied by Northern blot and immunoblot analysis. RESULTS: As a result of irradiation, increase of the mitochondrial membrane potential was found to occur in irradiated hepatocytes both in the presence or in the absence of CaCl2. The hyperpolarization of the mitochondrial membrane is assumed to cause an increase in mitochondrial Ca2+ uptake that was measured in isolated mitochondria. Finally, an increase in c-fos expression was found in irradiated hepatocytes when incubated in the presence of CaCl2. CONCLUSION: This paper gives additional information on the mechanism by which He-Ne laser light, either directly or in a cascade-like effect dependent on increase in cell Ca2+, can cause cell stimulation.

Animals↗
PubMed2001

Hypothalamic regulation of sleep.

The recent discovery linking narcolepsy, a sleep disorder characterized by very short REM sleep latency, with a neuropeptide that regulates feeding and energy metabolism, provides a way to understand how several behaviors may be disrupted as a result of a defect in this peptide. In this chapter we review the evidence linking hypocretin and sleep, including our own studies, and propose that a defect in the lateral hypothalamus that also involves the hypocretin neurons is likely to produce a disturbance in sleep, mood, appetite, and rhythms.

Animals↗
PubMed2001

Impact of patient feedback on the interpersonal skills of general practice registrars: results of a longitudinal study.

CONTEXT: A general practice vocational training program. OBJECTIVES: To examine the impacts and implications of different models of systematic patient feedback on the development of general practice (GP) registrars' interpersonal skills as they progressed through a GP vocational training program. DESIGN: A longitudinal study in which GP registrars were randomly assigned to three models of patient feedback: a control group and two intervention groups. The major source of data gathering was through the Doctors' Interpersonal Skills Questionnaire (DISQ) which was administered to patients immediately after their consultation. SUBJECTS: 210 GP registrars, 104 GP supervisors and 28 156 patients. RESULTS: Multivariate analysis techniques (including repeated-measures analysis) tested the effectiveness of the interventions. Findings showed that systematic patient feedback at regular intervals throughout GP training resulted in sustained levels of interpersonal skills. The most significant gains in interpersonal skills for both intervention groups occurred in the earlier stages of general practice training. Most registrars found the experience of patient feedback useful for gaining a better understanding of their interpersonal skills and for identifying areas in which they needed to improve. GP supervisors valued the opportunity to receive patient feedback themselves and found the activity a useful adjunct to their preceptor role. CONCLUSIONS: Patients, by providing feedback on doctors' interpersonal skills, have been able to contribute to improving the quality of the patient-doctor interaction. GP registrars and their supervisors value highly the role of patient feedback in interpersonal skill development.

Adult↗
PubMed2001

Conservative surgery in breast cancer. Significance of resection margins.

We approached the issue of surgical margins in the conservative treatment of breast cancer by examining the literature germane to four precise questions: At what distance from the macroscopic margin of the tumour should the resection margin be? To what extent do histologically clear resection margins indicate complete local control of the disease? To what extent do histologically involved margins indicate persistence of disease? and Does the local recurrence rate correlate with the status of the resection margin? We propose categorizing margin involvement into five groups (absent, focal, minimal, moderate and extensive involvement) according to strict histological criteria, and assigning increasingly aggressive subsequent treatments according to the extent of any margin involvement.

Journal Article↗
PubMed2001

The "Nordstrom suture" to enhance scalp reductions.

The authors compared the results of 10 scalp reductions using the "Nordstrom suture" with the earlier published results of scalp reductions without a device to prevent stretch-back and of reductions with extenders. At 1 month postoperatively, the Nordstrom suture eliminated the stretch-back of 8.3 mm seen in earlier studies and, in fact, it shrank the bald area. The average shrinking achieved with the Nordstrom suture was 16.9 mm (i.e., 143 percent improvement over scalp reductions alone). Scalp extenders shrank the bald area, but the Nordstrom suture shrank the area about three times more than extenders at 1 month postoperatively.

Alopecia↗
PubMed2001

One-step detection and genotyping of human papillomavirus in cervical samples by reverse hybridization.

This study describes a nonisotopic polymerase chain reaction-reverse hybridization-based method (PCR-RH) for the one-step detection and genotyping of anogenital human papillomavirus (HPV) in a microwell format. HPV DNA was amplified and labeled by PCR using GP5+/GP6+ primers. Labeled amplicons were hybridized to 20 HPV type-specific capture probes anchored to the surface of plastic microwells and detected by an immunoenzymatic assay. Assay sensitivity was <50 pg labeled amplicon, and no cross-reactivity was observed, as determined by hybridizing serial dilutions of labeled PCR products to either matched or mismatched capture probes. The assay was tested on 66 clinical samples (23 specimens with normal histology, I fibropapilloma, 26 cervical intraepithelial neoplasia grade 1 [CIN1], 9 CIN2, and 7 CIN3) and compared with a method based on restriction fragment length polymorphism (RFLP) of PCR products. PCR-RH and PCR-RFLP performed equally well on clinical samples. The overall HPV detection rate was similar: 65.1% (43/66) for PCR-RH and 57.6% (38/66) for PCR-RFLP. HPV DNA was found in all CIN2 and CIN3 samples by both methods; however, PCR-RH detected more positives among normal biopsy samples and CINI cases. Overall, there was good agreement between the two genotyping methods, but RH yielded fewer cases with undetermined HPV genotype.

Consensus Sequence↗
PubMed2001

Radioimmunoassay to detect antitransglutaminase autoantibodies is the most sensitive and specific screening method for celiac disease.

OBJECTIVE: The aim of this study was to establish the most sensitive and specific screening method for celiac disease. We tested three methods based on different principles, which all detect autoantibodies against the same antigen (tissue transglutaminase). METHODS: Sixty-two celiac children at the first biopsy (group 1), 78 celiac children on a gluten-free diet (group 2), 14 celiac children on a gluten-challenge (group 3), and 56 controls with a normal duodenal mucosa (group 4) were studied. The methods used were: 1) radioimmunoprecipitation assay using recombinant tissue transglutaminase (RIA); 2) commercial enzyme immunoassay using guinea pig tissue transglutaminase (ELISA); and 3) indirect immunofluorescence method for detection of antiendomysium antibodies (IF-EMA). RESULTS: RIA antitransglutaminase autoantibodies were detected in 100% of group 1, 43.6% of group 2, 100% of group 3, and none of the control subjects. ELISA antitransglutaminase autoantibodies were detected in 90.3% of group 1, 9% of group 2, 78.6% of group 3, and in none of the control subjects. IF-EMA were detected in 95.2% of group 1, 11.5% of group 2, 92.3% of group 3, and 1.8% of the controls. CONCLUSIONS: Our results demonstrate a very high sensitivity and specificity of the RIA method to detect antitransglutaminase autoantibodies in comparison to ELISA and IF-EMA assays. We can explain this finding with the use of human recombinant antigen and the increased capacity of the RIA method to detect low titers of autoantibodies. If our data are confirmed by studies on larger series, tissue transglutaminase RIA could be proposed as the best screening method for celiac patients.

Adolescent↗
PubMed2001

The practice accreditation and improvement survey (PAIS). What patients think.

BACKGROUND: The Practice Accreditation and Improvement Survey (PAIS) is an endorsed instrument by the Australian General Practice Accreditation Limited (AGPAL) for seeking patient views as part of the accreditation of Australian general practices. METHOD: From September 1998 to August 2000, a total of 53,055 patients completed the PAIS within 449 general practices across Australia, which is about 8% of all Australian general practices. The validity and reliability of the PAIS instrument was assessed during the study. Patient views were also analysed via 27 items relating to doctors' interpersonal skills, access, availability and patient information. RESULTS: PAIS was found to have sound validity and reliability measures. Patient evaluations showed a range of scores for the 27 items (69-91%). Lower scoring areas were issues about access, availability and availability of information for patients. DISCUSSION: Users of general practice rate the doctors' interpersonal skills (capability) more highly than other practice service issues (capacity). There is, in patients' views, much more room for improving these capacity aspects of general practice. CONCLUSION: Future research should explore how practices act on the results of patient feedback, and which practice based strategies are more effective in raising standards of care from a patient's perspective.

Accreditation↗
PubMed2000

A novel frameshift mutation of the mtDNA COIII gene leads to impaired assembly of cytochrome c oxidase in a patient affected by Leigh-like syndrome.

We report on a novel frameshift mutation in the mtDNA gene encoding cytochrome c oxidase (COX) subunit III. The proband is an 11-year-old girl with a negative family history and an apparently healthy younger brother. Since 4 years of age, she has developed a progressive spastic paraparesis associated with ophthalmoparesis and moderate mental retardation. The presence of severe lactic acidosis and Leigh-like lesions of putamina prompted us to perform muscle and skin biopsies. In both, a profound, isolated defect of COX was found by histochemical and biochemical assays. Sequence analysis of muscle mtDNA resulted in the identification of a virtually homoplasmic frameshift mutation in the COIII gene, due to the insertion of an extra C at nucleotide position 9537 of mtDNA. Although the 9537C(ins) does not impair transcription of COIII, no full-length COX III protein was detected in mtDNA translation assays in vivo. Western blot analysis of two-dimensional blue-native electrophoresis showed a reduction of specific crossreacting material and the accumulation of early-assembly intermediates of COX, whereas the fully assembled complex was absent. One of these intermediates had an electrophoretic mobility different from those seen in controls, suggesting the presence of a qualitative abnormality of COX assembly. Immunostaining with specific antibodies failed to detect the presence of several smaller subunits in the complex lacking COX III, in spite of the demonstration that these subunits were present in the crude mitochondrial fraction of patient's cultured fibroblasts. Taken together, the data indicate a role for COX III in the incorporation and maintenance of smaller COX subunits within the complex.

Base Sequence↗
PubMed2000

Expression of protein tyrosine phosphatase alpha (RPTPalpha) in human breast cancer correlates with low tumor grade, and inhibits tumor cell growth in vitro and in vivo.

Tyrosine phosphorylation is controlled by a balance of tyrosine kinases (PTKs) and protein tyrosine phosphatases (PTPs). Whereas the contribution of PTKs to breast tumorigenesis is the subject of intense scrutiny, the potential role of PTPs is poorly known. RPTPalpha is implicated in the activation of Src family kinases, and regulation of integrin signaling, cell adhesion, and growth factor responsiveness. To explore its potential contribution to human neoplasia, we surveyed RPTPalpha protein levels in primary human breast cancer. We found RPTPalpha levels to vary widely among tumors, with 29% of cases manifesting significant overexpression. High RPTPalpha protein levels correlated significantly with low tumor grade and positive estrogen receptor status. Expression of RPTPalpha in breast carcinoma cells led to growth inhibition, associated with increased accumulation in G0 and G1, and delayed tumor growth and metastasis. To our knowledge, this is the first example of a study correlating expression level of a specific bona fide PTP with neoplastic disease status in humans.

Animals↗
PubMed2000

Design, implementation, and evaluation at entry of a prospective cohort study of homosexual and bisexual HIV-1-negative men in Belo Horizonte, Brazil: Project Horizonte.

BACKGROUND AND OBJECTIVES: Project Horizonte, an open cohort of homosexual and bisexual HIV-1-negative men, is a component of the Minas Gerais AIDS Vaccine Program of the Federal University of Minas Gerais, Belo Horizonte, Brazil. Its objectives included the evaluation of seroincidence of HIV, to ascertain the role of counseling on behavior modification and to assess their willingness to participate in future HIV vaccine trials. METHODS: Various means of recruitment were used, including pamphlets, notices in community newspapers, radio, and television, at anonymous testing centers, and by word of mouth. RESULTS: From October 1994 to May 1999, 470 volunteers were enrolled. Their mean age was 26 years and over 70% of them had high school or college education. During the follow-up, they were seen every 6 months, when they received counseling and condoms, and when HIV testing was done. Eighteen seroconversions were observed, and the incidence rates estimates were 1.75 per 100 and 1.99 per 100 person-years, for 36 and 48 months of follow-up, respectively. During the entire period, 139 volunteers were lost to follow-up. Among them, 59 (42.4%) never returned after the initial visit and 51 (36.7) came only once after their initial visit. No losses were observed for those observed during follow-up for more than 3 years. At enrollment, 50% of participants said they would participate in a vaccine trial, and 30% said they might participate. CONCLUSIONS: The results obtained up to this moment confirm the feasibility of following this type of cohort for an extended period, estimating HIV incidence rate, and evaluating counseling for safe sexual practices in preparation for clinical trials with candidate HIV vaccines in Brazil.

Adult↗
PubMed2000

Diabetic Foot in the Elderly: Capillaroscopic Findings.

Microangiopathy is the most frequent complication of diabetes mellitus. It frequently precedes metabolic and biohumoral pathology. The diabetic foot is a particular aspect of the disease. Capillary videomicroscopy has proven to be a valuable technique for detecting early morpho-functional changes in the microcirculation in vivo. It is performed at the fingers' nailfold, at conjunctiva, and on the skin. This study aims to propose a qualitative assessment of microvascular complications in elderly patients with diabetes mellitus by toe nailfold capillary microscopy.

Journal Article↗
PubMed2000

Imaging active lymphocytic infiltration in coeliac disease with iodine-123-interleukin-2 and the response to diet.

Coeliac disease is diagnosed by the presence of specific antibodies and a jejunal biopsy showing mucosal atrophy and mononuclear cell infiltration. Mucosal cell-mediated immune response is considered the central event in the pathogenesis of coeliac disease, and untreated coeliac patients show specific features of T-cell activation in the small intestine. Here we describe the use of iodine-123-interleukin-2 scintigraphy in coeliac patients as a non-invasive tool for detection of lymphocytic infiltration in the small bowel and its use for therapy follow-up, and we demonstrate the specificity of binding of labelled-IL2 to activated lymphocytes by ex-vivo autoradiography of jejunal biopsies. 123I-IL2 was administered i.v. [74 MBq (2 mCi)], and gamma camera images were acquired after 1 h. Ten patients were studied with 123I-IL2 scintigraphy at diagnosis and seven were also investigated after 12-19 months of gluten-free diet. Results were expressed as target-to-background radioactivity ratios in six different bowel regions before and after the diet. At the time of diagnosis all patients showed a significantly higher bowel uptake of 123I-IL2 than normal subjects (P < 0.003 in all regions). A significant correlation was found between jejunal radioactivity and the number of IL2R + ve lymphocytes per millimetre of jejunal mucosa as detected by immunostaining of jejunal biopsy (r2 = 0.66; P = 0.008). Autoradiography of jejunal biopsies confirmed that labelled-IL2 only binds to activated T-lymphocytes infiltrating the gut mucosa. After 1 year of the diet, bowel uptake of 123I-IL2 significantly decreased in five out of six regions (P < 0.03), although two patients still had a positive IL2 scintigraphy in one region. We conclude that 123I-IL2 scintigraphy is a sensitive non-invasive technique for assessing in vivo the presence of activated mononuclear cells in the bowel of patients affected by coeliac disease. Unlike jejunal biopsy, this method provides information from the whole intestine and gives a non-invasive measure of the effectiveness of the gluten-free diet.

Adult↗
PubMed2000

Computed tomography of the small bowel in adult celiac disease: the jejunoileal fold pattern reversal.

The aim of this retrospective study was to establish whether the distinctive intestinal fold pattern of celiac disease (CD), known by barium studies as jejunoileal fold pattern reversal (JFPR) may be recognized at CT. The number of intestinal folds per 2.5 cm, seen at CT, were counted in the jejunum and in the ileum of 22 adult patients with CD and compared with the folds of 30 consecutive subjects in whom an intestinal disease had been excluded. The results were submitted to statistical analysis by Student's t-test. In the control group the number of folds per 2.5 cm were 4.88 (SD +/- 0.78) in the jejunum and 2.84 ( +/- 0.62) in the ileum; in the CD group the number of folds were 2.42 ( +/- 1.61) in the jejunum and 5.11 ( +/- 1.24) in the ileum. There was a statistically significant difference in the number of jejunal and ileal folds between the CD patients and the control group (in both cases p < 0.001). The JFPR was seen in 15 patients with CD (68.2 %) but in none of the controls. Our study shows that JFPR is not a normal finding and can be demonstrated by CT in the majority of patients with CD.

Adult↗
PubMed2000

Impact of nodal status on indication for adjuvant treatment in clinically node negative breast cancer. Istituto Nazionale per lo Studio e las Cura dei Tumori.

We addressed the problem of the need for axillary dissection in clinically node-negative breast cancer by determining how the information provided by the dissection suggests a different treatment to that indicated by primary tumour characteristics and age alone. We examined retrospectively 260 cases of clinically node negative early breast cancer all of whom underwent breast surgery, radiotherapy and axillary dissection. We assigned adjuvant therapy according to accepted guidelines with and without consideration of pathological node status and compared the difference. Fifty-six patients had involved axillary nodes. There was no change in adjuvant chemotherapy indication for the 44 cases over 65 years. The change in indication for the remaining 216 cases was 18.5% to 6%, depending on whether none or all of the intermediate risk patients were originally assigned chemotherapy (all were originally assigned tamoxifen). Since the trend is for most intermediate risk patients is to be assigned adjuvant chemotherapy, and since tamoxifen is anyway considered effective therapy for low and intermediate risk patients, we conclude that the information provided by axillary dissection is probably not necessary if guidelines recommending wide application of systemic adjuvant chemotherapy are applied. Satisfactory prognostic information can be obtained by consideration of primary tumour characteristics, while new prognostic markers are likely to further refine prognostic precision in the near future.

Adult↗
PubMed2000

Assessment of hospitalised cancer patients' needs by the Needs Evaluation Questionnaire.

BACKGROUND: Cancer disease modifies the order and the nature of needs connected with the state of health. The aim of this study was to evaluate the informative, psychological, social and practical needs of hospitalised cancer patients by means of the Needs Evaluation Questionnaire (NEQ), an instrument designed concisely for the convenience of patients and medical staff. PATIENTS AND METHODS: Different samples of consecutive hospitalised cancer patients were involved in the various phases of designing the instrument: 30 patients for items identification, 101 patients for completeness and acceptability evaluation, 423 patients for construct validity and prevalence of needs; content and reliability analysis were performed on 2 subsamples of, respectively, 60 and 88 of the patients from the last sample. RESULTS: The validation analysis showed rather good reliability, structure validity and internal consistency of the questionnaire. The prevalence analysis showed that the most common needs were: 'more information about my future conditions' (74%); 'more information about my diagnosis' (56%); 'more information about the exams I am undergoing' (52%); 'more explanations on treatments' (51%); 'to have a better dialogue with clinicians' (57%); 'better services from the hospital' (bathrooms, meals, cleaning) (56%). CONCLUSIONS: The NEQ, self-completed by patients, has proven to be a useful clinical tool for obtaining a systematic and undistorted overview of the principal needs with respect to the state of health of patients. This instrument, which can also be administered by persons not belonging to the health care system such as volunteers, and inserted into the patients' hospital charts, could be used by the medical staff to identify the real needs of patients at an early stage.

Female↗