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Biomedical subjects

L Bianchi

Publications and source records attributed to L Bianchi.

At least 199 records · Page 11Linked to original sources
PubMed1995

Photoinduction of micronuclei by 4,4',6-trimethylangelicin and 8-methoxypsoralen in different experimental models.

The frequencies of micronuclei induced by treatment with 4,4',6-trimethylangelicin (TMA) and 8-methoxypsoralen (8-MOP) have been compared in the following experimental models: (1) peripheral normochromatic erythrocytes (NCE) during 10 days after single p.o. administration of TMA or 8-MOP in male and female mice; (2) peripheral NCE during photocarcinogenesis by TMA or 8-MOP topically administered to female mice; (3) primary cultures of human skin fibroblasts treated with TMA or 8-MOP. The frequency of micronuclei in peripheral NCE of mice (both sexes) was significantly enhanced after p.o. administration of TMA or 8-MOP. This latter was more active than TMA in inducing chromosomal damage. No increased frequencies of micronuclei in peripheral NCE were detected in mice subjected to TMA or 8-MOP photocarcinogenic treatment, even when malignancies developed. In human fibroblast cultures, at equimolar concentrations, the induction of lethal effects by TMA in the presence of 365-nm radiation was higher than that exerted by 8-MOP. At equal survival, however, TMA showed practically the same activity as 8-MOP in the induction of micronuclei. Our findings provide evidence of genotoxicity by TMA administered p.o. without irradiation and give further information about photogenotoxicity of these substances.

Animals↗
PubMed1995

Nuclear binding of cell cycle-related proteins: cyclin A versus proliferating cell nuclear antigen (PCNA).

We have investigated the cell cycle-dependent nuclear binding of cyclin A and of the proliferating cell nuclear antigen (PCNA) in asynchronously growing human fibroblasts. To this purpose, we have applied flow cytometry immunofluorescence, a powerful technique for elucidating the cell cycle phase during which the nuclear binding occurs. We have observed that, in striking contrast with the distribution of nuclear-bound PCNA which is restricted to S phase, the immunofluorescence signal of the nuclear-bound form of cyclin A is high in the G1 and G2 phases of the cell cycle. These results suggest the involvement of nuclear-bound cyclin A in the G1/S and G2/M phase transitions.

Biomarkers↗
PubMed1995

Differential regulation by N-methyl-D-aspartate and non-N-methyl-D-aspartate receptors of acetylcholine release from the rat striatum in vivo.

The modulation of striatal cholinergic neurons by glutamatergic inputs was studied by monitoring the output of acetylcholine collected via a transversal microdialysis probe implanted into the striatum of freely moving rats. A transversal microdialysis membrane was inserted in the striatum and acetylcholine or GABA levels in the dialysate were measured. Acetylcholine levels in the dialysate were quantified by a high-performance liquid chromatography method with an electrochemical detector, while GABA levels were measured by a high-performance liquid chromatography method with a fluorescence detector. The dialysis membrane was perfused with Ringer solution containing 7 microM physostigmine sulphate and drugs, dissolved in the perfusion solution, were administered locally via the dialysis membrane. Local administration of the N-methyl-D-aspartate antagonist 3-[(RS)-2-carboxypiperazin-4-yl]-propyl-1-phosphonic acid (25-100 microM) brought about a decrease in striatal acetylcholine output which was dose-dependent, reversible and partially antagonized by 100 microM N-methyl-D-aspartate. On the other hand, local administration of the non-N-methyl-D-aspartate antagonist 2,3-dihydroxy-6-nitro-7-sulfamoil-benzo(F)quinoxaline was followed by an increase in acetylcholine output which reached a maximum of about +55% at 12.8 microM 2,3-dihydroxy-6-nitro-7-sulfamoil-benzo(F)quinoxaline and was readily reversed when the drug was withdrawn from the perfusion solution. Local administration of the non-N-methyl-D-aspartate receptor agonist (S)-alfa-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (50 and 200 microM) decreased acetylcholine output and this effect was reversed by simultaneous perfusion with the GABA antagonist bicuculline (50 microM).(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholine↗
PubMed1995

Improvement of pregnancy and implantation rates in cyclic women undergoing oocyte donation after long-term down-regulation.

An oocyte donation programme was carried out in 122 patients aged between 40 and 49 years for a total of 225 replacement cycles. Eggs were donated by 103 women undergoing assisted reproduction technologies in our infertility centre. Recipients were divided into different groups according to whether they were menopausal (group A) or cyclic and treated with short- (group B) or long-term (group C) gonadotrophin-releasing hormone analogues. In group C, the ovarian suppression of the patients was prolonged with the aim of producing a type of artificial menopause. Oocyte donors were aged between 21 and 35 years, and were equally distributed between the different groups. There were significant differences in pregnancy and implantation rates according to ovarian status: 30.8 and 16.1% respectively in group A, 30.6 and 17.7% respectively in group C versus 10.4 and 5.6% respectively in group B. Apart from improved pregnancy and implantation rates in cyclic women aged > 40 years after long-term down-regulation, these data seem to demonstrate an important role for the endometrium in the implantation process.

Adult↗
PubMed1995

Pachydermoperiostosis: study of epidermal growth factor and steroid receptors.

Pachydermoperiostosis is a rare osteo-cutaneous disease characterized by hypertrophy of bones and surrounding soft tissues. The cutaneous manifestations include coarsening of facial features, cutis verticis gyrata, digital clubbing, hyperhidrosis and seborrhoea. The pathogenetic mechanism of the disease is still debated, and proposed aetiological factors include genetic influences, anomalies in fibroblast activity, or alteration in peripheral blood flow. We studied a patient with the incomplete form of pachydermoperiostosis, assessing epidermal growth factor receptor (EGF-R) and sex hormone steroid receptors (SR) in the affected skin, and also evaluating the urinary excretion of EGF. The results showed high levels of nuclear steroid receptors, increased cytosolic oestrogen receptors, and no detectable progesterone and androgen cytosolic receptors. EGF-R was also undetectable, and the urinary excretion of EGF was elevated. These findings suggest that the increased tissue sensitivity to circulating sex-steroids could induce enhanced tissue EGF/transforming growth factor alpha (TGF-alpha) production and utilization. The SR-EGF-R system could therefore be involved in determining hypertrophy of the affected tissues.

Adult↗
PubMed1995

Intramuscular myxoma of the face: an unusual localization. A clinicopathological study.

BACKGROUND: Intramuscular myxoma is a rare benign mesenchymal lesion. Only very rare cases of cutaneous localization of this tumor have been described, in particular related to the somatic soft tissues of the face. This unusual localization may clinically mimic nodular or cystic facial lesions having different origins. OBJECTIVE: The aim of our work was to well characterize the phenotype of the spindle cells characteristic of intramuscular mixoma. METHODS: Tissue samples were processed for morphological and ultrastructural studies. Moreover, immunohistochemical stainings were performed to characterize the expression of different nonmuscular and muscular cytoskeletal proteins. RESULTS: The tumor was composed of sparse spindle cells embedded in a prominent mucoid matrix. Besides the predominance of a fibroblast-like appearance, some neoplastic cells displayed immunohistochemical and ultrastructural features resembling either myofibroblasts or primitive mesenchymal cells, with a modulation of cell actin expression. CONCLUSION: The presence of multiple phenotypes of nonmuscular, mesenchymal pathway of differentiation can be considered a peculiar feature of intramuscular myxoma.

Facial Neoplasms↗
PubMed1995

Solid alveolar rhabdomyosarcoma of the hand in adolescence: a clinical, histologic, immunologic, and ultrastructural study.

Rhabdomyosarcoma (RMS), a high-grade, malignant, skeletal muscle tumor, represents approximately 5% of neoplasms in children. The poorly differentiated forms of RMS are often not easily diagnosed and classified. Among the four histologic variants, alveolar RMS is the least frequently reported subtype. A poorly differentiated solid variant of alveolar RMS occurred on the right hand of a 16-year-old girl. Because of the tumor size, local invasiveness, and occurrence of cutaneous and breast metastases at presentation, the clinical staging was group IV (T2/NO/M1). Surgical excisions of the primary and metastatic locations were performed and chemotherapy with vincristine, dactinomycin, cyclophosphamide, and doxorubicin was administered. Light and electron microscopy studies revealed a solid proliferation with a focal alveolar pattern of monomorphous, small, round neoplastic cells without easily detectable muscular morphologic features. The skeletal muscle origin was revealed by the positive immunostaining for desmin, alpha-sarcomeric actin, muscle-specific actins, and enolase, and confirmed by immunoblotting for desmin. Despite the age of our patient, which is considered by some authors an independent predictor of outcome, all prognostic variables were unfavorable. However, a disease-free interval during three years of follow-up underlines the importance of multidisciplinary regimens for the treatment of this rare solid tumor of childhood and adolescence.

Adolescent↗
PubMed1995

Rat tissue concentrations of chlorimipramine, chlorpromazine and their N-demethylated metabolites after a single oral dose of the parent compounds.

A single oral dose of 90 mg kg-1 chlorimipramine or chlorpromazine, corresponding to 54.5 or 55.9 mumol, respectively, was given to male Sprague-Dawley rats and concentrations of parent drugs and their N-desmethyl metabolites measured by gas chromatography in plasma and major organs (brain, liver, lung, kidney, heart, spleen and peritoneal fat). In the case of chlorimipramine, N-desmethyl metabolite levels were consistently higher than those of the parent drug for the entire observation period of 24 h in all tissues except fat, while lower N-desmethyl metabolite/parent compound ratios were observed for chlorpromazine. N-Desmethyl metabolite kinetics of chlorimipramine appeared to be elimination-rate limited, while those of chlorpromazine were formation-rate limited. In all analysed organs, the maximu detectable drug+metabolite concentrations accounted for only 2.3 and 4.6% of the initial dose of chlorimipramine and chlorpromazine. Chlorpromazine treatment gave rise to an area under the total amount-time curve (AUC0-24) for parent drug+metabolites, 3.9-fold that for chlorimipraine. Closer scrutiny discloses a conversion ratio of parent compound to N-desmethyl metabolite of 1.1 for chlorpromazine and of 2.2 for chlorimipramine, indicating the greater efficiency of chlorimipramine metabolism in all compartments. The expected high conversion index found in the liver (2.3) reaches its maximum of 5.4 in the lung. Fractional data analysis of chlorimipramine and chlorpromazine distribution patterns revealed greater organ transfer for the N-desmethyl metabolites than for the more stably-located parent compounds. The N-desmethyl metabolites of chlorimipramine apparently moved from liver to lung, kidney and spleen, whereas N-desmethylchlopromazine moved preferentially to the brain and lung tissue. This single dose study of chlorimipramine and chlorpromazine kinetics, highlights the two distinct dispositional processes at work in the rat in all likelihood, attributable to different absorption patterns, to a slower metabolism and, thus, to the longer persistence of chlorpromazine.

Adipose Tissue↗
PubMed1995

Twenty-four-hour noninvasive blood pressure monitoring and pain perception.

Although a hypertension-related hypalgesia has been described, the relation between pain perception and the 24-hour blood pressure trend is still unknown. The ambulatory blood pressure monitoring parameters and dental pain sensitivity were correlated in 67 male subjects. The pulpar test (graded increase of test current of 0 to 0.03 mA) was performed on three healthy teeth, and mean dental pain threshold (occurrence of pulp sensation) and pain tolerance (time when the subjects asked for the test to be stopped) were evaluated. Three groups of subjects with normal (n = 34), intermediate (n = 13), and high (n = 20) blood pressure values were identified according to ambulatory monitoring results. Pain threshold differed among the three groups (P < .02), being higher in the group with highest blood pressure. The groups of hypertensive subjects showed higher pain tolerance than the normotensive group (P < .02). Pain threshold was correlated with 24-hour, diurnal, and nocturnal blood pressure values. Pain tolerance was also related to 24-hour blood pressure and to diurnal and nocturnal diastolic and mean arterial pressure values. Systolic and diastolic blood pressure loads were significantly associated with pain threshold, and diastolic load was also associated with tolerance. The blood pressure variability (SD) did not relate to pain perception. The 24-hour arterial pressure was more closely associated with pain perception than the blood pressure values obtained before the pulpar test. A close correlation between pain perception and 24-hour ambulatory blood pressure was demonstrated.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Guidelines for the management of community-acquired pneumonia in adults. Italian Society of Pneumology. Italian Society of Respiratory Medicine. Italian Society of Chemotherapy.

In general practice Community-acquired Pneumonia (CAP) is most often treated on an empyrical basis. Therefore, it is of the utmost importance to know the epidemiology of respiratory pathogens in order to give some guidelines for the empirical management of CAP. At present in cases of mild and moderate severity, ampicillin or amoxycillin, preferably in association with sulbactam and clavulanic acid respectively, and macrolides are the antibiotics of first choice. The latter can be an alternative to beta-lactams when Legionella, Mycoplasma and Chlamydia are the suspected etiologic agents or when patients are allergic to penicillins. They can also be used in combination with beta-lactams when etiological diagnosis is extremely uncertain. The course and severity of the disease, a chest radiograph, the results of microbiological and other laboratory examinations will determine the choice of further antibiotic treatment and other therapeutic measures, if necessary.

Adult↗
PubMed1995

Pregnancies in postmenopausal women over 50 years old in an oocyte donation program.

OBJECTIVE: To determine the potential of the aging uterus in terms of pregnancy, implantation, and abortion rates, and obstetric complications in postmenopausal women age 50 and over, receiving oocyte donation. DESIGN: Retrospective data analysis. SETTING: A tertiary infertility center. PATIENTS: Thirty-four postmenopausal women (50 to 62 years of age) undergoing a total of 61 cycles of oocyte donation. INTERVENTIONS: Hormone replacement therapy (HRT) was given using increasing doses of 17 beta-E2 (2, 4, and 6 mg) and 100 mg of P in oil. MAIN OUTCOME MEASURES: Pregnancy, abortion, and implantation rates, and pregnancy outcome. RESULTS: There were 34 patients treated through 61 cycles. Fifty-five transfer cycles were performed. A total of 18 clinical pregnancies were achieved with a pregnancy rate per transfer of 32.7% and per patient of 52.9%. There was one abortion, resulting in an abortion rate of 5.5%. Twenty-one of the 116 transferred embryos implanted, resulting in an implantation rate of 18%. No statistically different rates were found in oocytes donors. CONCLUSION: Women over the age of 50 and up to 62 can become pregnant using donated oocytes. The aging uterus after HRT allows implantation as well as in young women, and it is able to carry pregnancy to term apparently without any problems.

Abortion, Spontaneous↗
PubMed1995

Effective radiation dose to the patient and to the general population from nuclear medicine procedures: variations in the last twenty-year period.

We have evaluated how changes in nuclear medicine (NM) techniques over the last twenty-year period have modified radiation exposure to the patient and population. For this purpose, we estimated the variations in the mean effective dose to the patient, and both the collective and the per capita effective dose to the population of the province of Varese, derived from radioisotope examinations carried out in the four NM Centers of this province in the years 1972, 1981, and 1991. Dosimetric calculations were based on ICRP Publication 53 for most of the radiopharmaceuticals used, and tissue weighting factors were based on ICRP Publication 60. The total number of NM exams carried out was 19,744 in 1972, 31,973 in 1981, and 23,623 in 1991. Between 1972 and 1991 there has been a substantial decrease in the effective irradiation to the patient and to the general population (mean effective dose to the patient: from 21.2 to 6 mSv; per capita mean effective dose: from 0.58 to 0.18 mSv), and in the per capita equivalent dose to some target organs, such as the thyroid (9.6-->1.5 mSv) and liver (0.51-->0.07 mSv). At the same time, there has been a significant increase in the per capita equivalent dose to the bladder (0.05-->0.48 mSv), skeleton (0.08-->0.36 mSv), and testes (0.02-->0.15 mSv), and a less marked increase to the ovaries (0.03-->0.06 mSv). The per capita equivalent dose to red marrow (0.13-->0.1 mSv) and to the large intestine (0.1-->0.12 mSv) did not change significantly.

Adolescent↗
PubMed1995

[Detection and typing of hepatitis C RNA in liver biopsies in comparison with histopathology].

Total RNA of 55 frozen liver biopsies were extracted and tested for the presence of HCV RNA and the genotype by RT-PCR using primers of the 5' non-coding region and a type specific primer set for HCV genotyping. In paralell, the activity of chronic hepatitis, the stage of fibrosis as well as chracteristic features of chronic hepatitis C were evaluated by conventional histology. HCV RNA was detected in 49 (89.1%) of 55 liver specimen by either primer set and genotyping was successful in 42 (76.4%) of liver biopsies. The samples were divided in 3 groups: Group A consisted of specimens infected with genotypes 1a, 2a and 2b (n = 13), Group B contained biopsies infected with genotype 1b (n = 24) and Group C were biopsies with two or no detectable genotype. The histology showed a significant higher degree of fibrosis/cirrhosis in Group B (genotype 1b) compared to Group A (11/24 vs. 0/13, p = 0.011). In addition, an advanced fibrosis/cirrhosis was found more often in Group C than B, however, this difference was not significant (5/15 vs. 0/13, p = 0.072). No difference was seen between the three groups with respect to the activity of chronic hepatitis, presence of lymphoid follicles, bile duct lesions or steatosis. We conclude that HCV RNA can readily be detected and typed in frozen liver tissue. Patients infected with HCV genotype 1b have an increased risk developing liver fibrosis and cirrhosis.

Biopsy↗
PubMed1995

Effects of arithmetic mental stress test on hypertension-related hypalgesia.

AIM: Though hypertension-related hypalgesia has been described, little is known about possible variation of pain perception after mental stress. The aims of the present study were to determine (1) whether mental stress can influence pain perception in normotensive and hypertensive subjects and (2) whether blood pressure levels before pain evaluation can account for changes in pain sensitivity. PATIENTS AND METHODS: A pulpar test (graded increase in test current of 0-0.03 mA applied on healthy teeth) was performed twice (time interval 15 min) in 62 subjects. Thirty-eight subjects (group 1) performed an arithmetic mental stress test immediately after the first pulpar test while 24 subjects (group 2) did not. The pain threshold (occurrence of pulp sensation) was evaluated as the mean value of three teeth tested on each subject and as the value on the most sensitive tooth. RESULTS: Twenty-eight subjects with normal 24-h blood pressure showed a lower mean pain threshold than 34 subjects with high 24-h blood pressure values (P<0.02). In group 1 (20 normotensives, 18 hypertensives), even when the mental stress increased the pretest blood pressure, the pressure values immediately before both pulpar tests remained similar. In the second pulpar test, a significant increase in the pain threshold on the most sensitive tooth was observed in group 1 (P<0.005). Though a trend towards an increase in the pain threshold was found in both the subgroups of normotensive and hypertensive subjects, the difference was significant in hypertensives only. However, group 2 subjects showed unchanged pain sensitivity on the second test. CONCLUSIONS: A mental stress-induced reduction in pain sensitivity was observed in the absence of change in arterial pressure measured immediately before pulpar tests. A blood pressure increase during the test and, more likely, cortical and humoral activation during stress, may account for the variation found in pain perception.

Adult↗
PubMed1994

[Giant cell hepatitis in adults].

Differential diagnosis of progressive cholestatic liver disease includes postinfantile giant-cell hepatitis, particularly in cases with negative serology for hepatitis viruses and in the absence of an intake of potentially hepatotoxic drugs. Diagnosis is made by the histologic demonstration of syncytial giant cells in liver. To the knowledge of the authors, some 70 cases have been published so far; however, the true prevalence of the disease appears to be much higher than commonly assumed. Hepatocellular giant cells, the only diagnostic marker, may be expressed in low copy numbers, and many cases thus easily escape recognition. Some 50% of the published cases are positive for autoantibodies in serum or combined with other features of autoimmunity. A correct diagnosis is important in view of the unfavorable prognosis with a rapidly progressive course in about half the cases. Fulminant liver failure and late cirrhotic stages are candidates for liver transplantation. After transplantation no recurrence of giant-cell hepatitis has been observed. Cases positive for autoantibodies have been successfully treated with corticosteroids; cholestatic forms appear to respond to ursodeoxycholic acid. Etiology of the disease is not settled. Some authors claim aberrant immunoreactivity from various causes to be responsible for the disease, others have presented evidence in favor of a paramyxovirus infection. In any case of cholestasis of unknown origin, serology for paramyxoviruses and a liver biopsy are recommended.

Autoantibodies↗