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Biomedical subjects

M Greco

Publications and source records attributed to M Greco.

At least 55 records · Page 3Linked to original sources

Specific helium-neon laser sensitivity of the purified cytochrome c oxidase.

PURPOSE: In order to gain some insight into the mechanism of interaction between Helium-Neon (He-Ne) laser light and mitochondrial cytochromes, the sensitivity of cytochrome electron transfer activity to He-Ne laser was tested. MATERIALS AND METHODS: Irradiation of solutions containing either purified cytochromes or dissolved rat liver mitochondria was carried out (wavelength 632.8 nm, fluence rate 10 mW cm(-2), fluence 2 J cm(-2)); the irradiation conditions were the ones able to affect cytochrome c oxidase (COX) activity in mitochondria (Pastore et al., 1994). RESULTS: Cytochrome c oxidation catalysed by COX was affected by He-Ne laser irradiation of the purified enzyme. This result was obtained from measurements of the pseudo-first-order kinetic constant and from determinations of the turnover number of the enzyme, performed at different cytochrome c/COX ratios. Consistently, the kinetic parameters of COX changed. On the contrary, no alteration in the rate of electron transfer catalysed by either cytochrome c or bc1 complex was found. CONCLUSIONS: This study shows that purified COX is a specific target of He-Ne laser light; therefore, COX may be considered to be a mitochondrial photo-acceptor.

Animals↗

Breast cancer patients treated without axillary surgery: clinical implications and biologic analysis.

OBJECTIVE: To evaluate the impact of breast carcinoma (T1-2N0) surgery without axillary dissection on axillary and distant relapses, and to evaluate the usefulness of a panel of pathobiologic parameters determined from the primary tumor, independent of axillary nodal status, in planning adjuvant treatment. METHODS: In a prospective nonrandomized pilot study, 401 breast cancer patients who underwent breast surgery without axillary dissection were accrued from January 1986 to June 1994. At surgery, all patients were clinically node-negative and lacked evidence of distant metastases after clinical or radiologic examination. A precise 4-month clinical and radiologic follow-up was performed to detect axillary or distant metastases. Patients with clinical evidence of axillary nodal relapse were considered for surgery as salvage treatment. Biologic characteristics of primary carcinomas were investigated by immunohistochemistry, and four pathologic and biologic parameters (size, grading, laminin receptor, and c-erbB-2 receptor) were analyzed to determine a prognostic score. RESULTS: The 5-year follow-up of these patients revealed a low rate of nodal relapses (6.7%), particularly for T1a and T1b patients (2% and 1.7%, respectively), whereas T1c and T2 patients showed a 10% and 18% relapse rate, respectively. Surgery was a safe and feasible salvage treatment without technical problems in all 19 cases of progressive disease at the axillary level. The low rate of distant metastases in T1a and T1b groups (<6%) increased to 15% in T1c and 34% in T2 patients. Analyzing the primary tumor with respect to the panel of pathologic and biologic parameters was predictive of metastatic spread and therefore can replace nodal status information for planning adjuvant treatment. CONCLUSIONS: Middle-term follow-up shows that the rate of axillary relapse in this patient population is lower than expected, suggesting that only a minimal number of microembolic nodal metastases become clinically evident. Avoidance of axillary dissection has a negligible effect on the outcome of T1 patients, particularly in T1a and T1b tumors with no palpable nodes, because the rate of axillary node relapse is very low for both. In T1 breast carcinoma, postsurgical therapy should be considered on the basis of biologic characteristics rather than nodal involvement. The authors' prognostic score based on the primary tumor identified patients who required postsurgical treatment, providing a practical alternative to axillary status for deciding on adjuvant treatment. Conversely, in the T2 group, the high rate of salvage surgery for axillary relapses, which is expected in tumors larger than 2.5 cm or 3.0 cm, represents a limit for avoiding axillary dissection. Preoperative evaluation of axillary nodes for modification of surgical dissection in this subgroup would be more useful more than in T1 breast cancer because of the high risk. Complete dissection is feasible without technical problems if precise follow-up detects progressive axillary disease.

Aged↗

An in-school CD-ROM asthma education program.

Computer-based education in schools is not novel. However, only a few computer games have been introduced into school-based health education programs. This study describes inclusion of an asthma education space adventure game into fourth-grade classrooms. Using the game improved asthma knowledge in the intervention classes. Children in the active participation classroom gained significantly more asthma knowledge over the observation period compared to the classroom that did not play the computer game. Knowledge gained was retained over a four-week period and the addition of physician-led talks appeared to add little to the knowledge gained. "Air Academy: The Quest for Airtopia" is an easy and successful tool for elementary grade asthma-related health education in schools.

Asthma↗

Consumers as educators: implementation of patient feedback in general practice training.

There is growing interest in the adoption of patient-based assessments for the training of general practitioners. Consumers are in a unique position to comment on the quality of the doctor-patient interaction. Involving consumers as partners with general practice (GP) registrars and GP educators in the development of a patient feedback instrument enhances the relevance and acceptability of consumers as educators in GP training. It also demonstrates that social and medical agendas can be harmonized. Two patient feedback instruments on interpersonal skills were trialed in a training program for general practitioners in Australia. It was found that one of the instruments was more discriminating than the other because of its different response scale.

Adult↗

Which kinds of lymph node metastases can FDG PET detect? A clinical study in melanoma.

UNLABELLED: The purposes of this study were to establish the diagnostic accuracy of FDG PET for lymph node metastases and to determine the smallest detectable volume of disease. METHODS: Using FDG PET, we preoperatively studied 56 lymph node basins in 38 patients with a clinical or instrumental diagnosis of lymph node metastases from melanoma. All lymph node basins underwent node dissection. The FDG PET results were compared with the postoperative histopathology results. PET images were obtained using a GE 4096 WB scanner, after injection of a mean activity of 496 MBq (range, 366-699 MBq) of FDG. RESULTS: The efficacy of FDG PET in the diagnosis of involved lymph node basins was good. Sensitivity was 95% (35/37); specificity, 84% (16/19); accuracy, 91% (51/56); positive predictive value, 92% (35/38); and negative predicative value, 89% (16/18). Metastases were shown histologically in 114 of 647 surgically removed lymph nodes. FDG PET detected 100% of metastases > or = 10 mm, 83% of metastases 6-10 mm, and 23% of metastases < or = 5 mm. Moreover, FDG PET had high sensitivity (> or = 93%) only for metastases with more than 50% lymph node involvement or with capsular infiltration. CONCLUSION: Our study shows that FDG PET has a reasonable sensitivity and specificity for detecting the presence or absence of lymph node metastases in patients with melanoma. However, even if able to detect small volumes of subclinical macroscopic disease, FDG PET cannot detect subclinical microscopic disease with acceptable sensitivity. The specificity of FDG PET is good, but some false-positive results may occur.

Adult↗

[Detection and genetic typing of human papillomaviruses in cervical biopsies in Cagliari Province].

INTRODUCTION: Human Papillomavirus (HPV) infection is considered an important risk factor for the development of cervical carcinoma. The aim of this work was to detect and genotype HPV DNA in cervical lesions from our Province. METHODS: HPV DNA was amplified by polymerase chain reaction (PCR) and genotyped by restriction fragment length polymorphism (RFLP) analysis. A total of 101 biopsies (43 koilocytic atypias, 20 CIN1, 19 CIN2, 17 CIN3 and 2 squamous carcinomas) were analyzed. RESULTS: HPV DNA was found in 41.8% of koilocytic atypias, in 95.0% of CIN1 and 100% of CIN2 and higher grade lesions. Only high risk genotypes were found in CIN2-3 and invasive carcinomas. HPV 16 was the most prevalent type in both CIN1 and CIN2-3 and the only HPV type found in situ and invasive carcinomas. HPV type 51 was found in 21.0% of CIN1 but it was rare in CIN2 and absent in more advanced lesions.

Adult↗

[Intestinal occlusion caused by an intramural ileo-cecal-colonic hematoma during treatment with oral anticoagulants].

The Authors report a case of bowel occlusion due to intramural ileocecocolic haematoma in a patient in treatment with oral anticoagulants. This case is interesting both to unusual etiology correlated to the localization and because there are many concomitant pathogenetic factors; this case was treated on urgency by bowel resection and it had a good prognosis. The Authors discuss the diagnostic and therapeutic difficulties and conclude that in patients with anticoagulant oral therapy an accurate clinical follow-up is required.

Aged↗

[Simultaneous detection and typing of human papillomavirus in cervical biopsies using PCR-reverse hybridization].

INTRODUCTION: Genotyping of Human papillomavirus (HPV) is an important step in the clinical evaluation of the oncogenic risk associated with HPV infection of cervical mucosa. The purpose of this work was to develop a fast PCR-reverse-hybridization assay (PCR-RH) for the simultaneous detection and genotyping of anogenital HPVs. METHODS: HPV DNA from cervical biopsies was amplified by consensus primer-PCR. Digoxigenin-labeled PCR products were hybridized to type-specific probes anchored to the surface of plastic microwells and revealed by an ELISA system. RESULTS: The method was tested on 115 clinical samples (81 koilocytic atypias, 11 CIN1, 10 CIN2, 12 CIN3 and 1 squamous carcinoma). HPV DNA was found in 56.7% koilocytic atypias, in 90.9% of CIN1 and in 100% of CIN2 and higher-grade lesions. Thus, PCR-RH is sensitive, rapid, easy-to-perform and readily applicable to the routine analysis of a large number of samples.

Biopsy↗

Fluctuation of HER2 expression in breast carcinomas during the menstrual cycle.

The hormonal milieu at time of tumor surgery seems to have a significant impact on survival in premenopausal breast cancer patients. Indeed, surgery performed during the follicular phase of the menstrual cycle was suggested to correlate with a poor prognosis. To investigate the relationship between prognosis and menstrual cycle at time of surgery, we analyzed the expression of some markers associated with tumor aggressiveness, such as the hormone receptors, HER2, p53, Bcl2, and cathepsin D in breast carcinomas obtained from 198 premenopausal women who underwent surgery during different phases of the menstrual cycle. HER2 overexpression was found to fluctuate in hormone receptor-positive tumors. In actual fact, 20% of the tumors removed during the follicular phase scored HER2-positive, versus 8% of those removed during the luteal phase. Similarly, a number of hormone receptor-positive tumor specimens, obtained from the same patients during follicular and luteal phases, were scored HER2-positive when the sample was removed during the follicular phase and HER2-negative when removed in the luteal phase. Southern blot analysis of the HER2 gene indicated that, in hormone receptor-positive cases, the overexpression of HER2 is often not associated with gene amplification. The finding that overexpression of the HER2 gene, associated with tumor aggressiveness, can fluctuate according to the hormonal milieu may explain the increased survival of patients operated during the luteal phase. It is also relevant to the selection and treatment of patients most likely to benefit from anti-HER2 antibody therapy.

Adult↗

Fasting-induced apoptosis in rat liver is blocked by cycloheximide.

The effect of cycloheximide (CH) on the fasting-induced changes of rat liver cell and protein turnover has been investigated. Late starvation phase (3-4-day-fasting period) was characterised by a decrease in liver weight and protein and DNA content. The loss of DNA was not related to liver cell necrosis but due not only to depression of cell proliferation as shown by the drop in the labelling index but also induction of apoptosis. This type of apoptosis was documented by the increase in the apoptotic index (cells labelled by TUNEL) and transglutaminase activity as well as by DNA fragmentation. The liver cells of fasted rats appeared smaller as shown by the higher cell density and DNA/protein ratio than in controls. Females were more resistant to fasting-induced apoptosis than males. A single dose of CH, a drug primary known as inhibitor of protein synthesis, induced or enhanced apoptosis in fed and 2-days fasted male rats, respectively, without any sign of cell necrosis. On the contrary, the administration of repeated doses of CH blocked apoptosis induced by fasting. CH "froze" protein and DNA content as well as apoptotic process at the level of 2 days-fasted rats. While fasting-induced liver protein loss resulted from a marked reduction in protein synthesis with a slight decrease in degradation, repeated treatment with CH virtually blocked protein loss by abolishing protein catabolism. These data suggest a direct relationship between the catabolic side of protein turnover and the apoptotic process.

Animals↗

Periodic breathing during sleep in patients affected by fibromyalgia syndrome.

Seventeen patients affected by fibromyalgia syndrome (FMS) (16 females and one male) and 17 matched healthy subjects underwent formal polysomnography, a sleep questionnaire and lung function tests. FMS patients slept significantly less efficiently than the healthy controls (p<0.01), had a higher proportion of stage 1 sleep (mean+/-SD, 21+/-6% versus 11+/-4%; p<0.001), less slow wave sleep (p<0.01) and twice as many arousals per hour of sleep (p<0.001). The respiratory pattern of FMS patients showed a high occurrence of periodic breathing (PB) (15+/-8% of total sleep time) in 15/17 patients, versus 2/17 control subjects. The short length of apnoeas and hypopnoeas did not affect the apnoea/hypopnoea index (5.1+/-3.5 versus 3.2+/-1.6; NS), but FMS patients had a greater number of desaturations per hour of sleep (8+/-5 versus 3+/-3; p<0.01). Pulmonary volumes did not differ between the two groups, but FMS patients had a lower transfer factor of the lung for carbon monoxide (TL,CO (5.8+1 versus 7.7+1 mmol x min(-1) x kPa(-1); p=0.001). PB occurrence correlated with TL,CO (r=-0.62; p=0.01), number of desaturations (r=0.76, p=0.001) and carbon dioxide tension in arterial blood (Pa,CO2) (r=-0.50; p=0.05). Stepwise multiple linear regression analysis showed desaturation frequency (p=0.0001) and TL,CO (p=0.029) to be the best predictors of PB percentage (R2 0.73; p=0.0001). Patients complaining of daytime hypersomnolence had a higher number of tender points, about twice as many arousals per hour and a lower sleep efficiency than patients who did not report this symptom. TL,CO was more impaired and the occurrence of PB was higher. The occurrence of periodic breathing in fibromyalgia syndrome patients, which was previously unreported, and is shown to be linked to a reduction of transfer factor of the lung for carbon monoxide could play a major role in the symptoms of poor sleep of these patients.

Disorders of Excessive Somnolence↗

Effect of fasting/refeeding on the incidence of chemically induced hepatocellular carcinoma in the rat.

Caloric restriction has been associated with a delay in the development of both spontaneous and induced neoplasia. In contrast, cycles of fasting/refeeding were shown by us and others to enhance the incidence of early lesions during chemical carcinogenesis in rat liver. The present, long-term study was undertaken to establish whether such a diffential effect would also extend to the later phases of cancer development, until the overt appearance of neoplasia. Male Fischer 344 rats were initiated with a single dose of diethylnitrosamine (DENA, 200 mg/kg i.p.) and starting 1 week later they were either exposed to three cycles of fasting (3 days) followed by refeeding (11 days) or were fed continuously. Seven weeks after DENA administration the rats were exposed to the resistant hepatocyte model of the liver tumor promotion protocol. All animals were killed 1 year after initiation. Incidence of hepatocellular carcinoma was 2-fold higher in the fasted/refed group compared with the controls (72 versus 36%). In addition, cancers were also larger and of higher histological grade in the former group, with one animal showing metastases to the lungs, while no metastases developed in control animals. Fasting caused a decrease in total liver DNA (from 25.2 +/- 1.1 to 16.5 +/- 1.1 mg after 3 days) which was associated with a decrease in hepatocyte labeling index and mitotic activity and high levels of single cell death (apoptosis). In contrast, a sharp increase in hepatocyte proliferation was observed on day 2 of refeeding and this was more pronounced in glutathione S-transferase 7-7 positive foci compared with surrounding liver (10.2 +/- 2.3 versus 4.6 +/- 0.8%). Such a proliferative wave was associated with a sharp decline in the incidence of cell death. It is concluded that fasting/refeeding performed early after initiation accelerates the development of chemically induced hepatocellular carcinoma in the rat.

Animals↗

Importance of the level of axillary involvement in relation to traditional variables in the prognosis of breast cancer.

Survival in breast cancer correlates with the presence of metastatic lymph nodes, so that removal and pathological examination of the axillary nodes provides the most important prognostic information and basis for planning subsequent therapy. However as the size of primary tumours at diagnosis is decreasing, the likelihood of axillary involvement is also declining, so that the indications for axillary dissection are undergoing radical revision. To definitively establish the value of removing all three axillary lymph node levels (as defined by Berg) in node positive breast cancer, retrospective analysis of a large series receiving complete dissection was carried out. consecutive breast cancer patients (n=1003) with positive axillary nodes were analyzed: all received identical axillary treatment and the three levels were tagged with metal disks to facilitate recognition and pathological examination. Follow-up (mean 97 months) was exceptionally complete. The length of disease-free and overall survival were taken as the primary endpoints. The variables considered in the statistical analysis were tumour size, number of metastatic nodes, axillary invasion by level (the three classic levels), perilymphnodal invasion and age. By univariate analysis, overall and disease-free survival decreased significantly as tumour diameter, number of involved lymph nodes, and involvement by axillary level increased. Multivariate analysis assessing the relative importance of these variables when all were considered together found that they were all important independent predictive factors for survival. This study confirms the importance of tumour size and number of metastatic axillary nodes as predictors of outcome in breast cancer. In addition, the level of axillary invasion as a third independent factor of equal importance to the established indicators was identified. When axillary dissection is performed it should be complete, and all three Berg levels tagged separately, so that involvement by level can be ascertained. This provides additional important prognostic information on which to base subsequent treatment decisions.

Adult↗

[The indications and controversies for the use of corticosteroids in respiratory deficits in the multiple-trauma patient].

The rational use of corticosteroids in terms of doses, timing and methods of administration, has proved useful in management of the effects of morbidity and mortality in respiratory insufficiency in multiple trauma patients. MPSS (methyl prednisone sodium succinate) is the drug of choice because, compared to other steroids, it penetrates lung tissue more easily (as demonstrated using autoradiographic techniques). The effect of reducing permeability, shown by MPSS, is more marked in the first 6 hours, followed by a progressive diminution. For this reason, it is advisable to administer the drug every 6-8 hours, irrespective of T 1/2 (12-36 h). However, in syndromes of post-traumatic respiratory distress, corticosteroid therapy is only symptomatic, namely it reduces short term mortality, but does not influence the prognosis in the event of persistent microembolism. On the other hand, it is important not to overlook the disadvantages and possible damaging effects linked to the use of corticosteroids in multiple trauma patients. With regard to the use of "alternative" type or support treatments to corticosteroids, the lack of markers documented using atraumatic and reliable techniques hinders the development and clinical application of specific and effective antioxidising treatments. However, alongside the perfection of methods of detecting markers, among the antioxidant drugs, a decisive contribution is expected from the lazaroids or 21-aminosteroids (synthesis steroids). With powerful scavenger activity and antioxidant properties (twice those of MPSS), the lazaroids can provide more suitable solutions to the complex therapeutic problems of these patients, also because they lack glucocorticoid and mineralocorticoid activity.

Adrenal Cortex Hormones↗