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Biomedical subjects

M Fini

Publications and source records attributed to M Fini.

At least 199 records · Page 11Linked to original sources
PubMed1980

Transitional cell carcinoma of the bladder. Differences between primary tumour and following relapses.

The presence of tumour-associated antigens in bladder carcinomas has been shown in leucocyte migration inhibition and lymphocyte stimulation using formalin-treated autologous tumour cells as antigen. The treatment of patients with an in vitro produced specific transfer factor enhances their reactivity in these tests. However, when tumour cells from relapses were substituted for those of the primary tumour, the reactivity previously observed was abolished. An antigenic modulation and/or a polymorphic expression of bladder tumour-associated antigens in secondary tumours is suggested and might be responsible for some immunological escapes.

Antigens, Neoplasm↗
PubMed1979

Influence of urine on "in vitro" crystallization rate of calcium oxalate: determination of inhibitory activity by a [14C]oxalate technique.

A simple radiochemical method is proposed for the in vitro assay of the inhibitory activity of urine with respect to calcium oxalate crystal growth using [14C]oxalate as a tracer. The method shows an improved sensitivity over existing methods and indicates that citrate, pyrophosphate and chondroitin sulphate are active inhibitors of calcium oxalate crystal growth down to concentrations of 10(-5), 10(-7) and 10(-10) mol/l respectively. The inhibitory activity in the urines of 12 recurrent calcium stone-formers was significantly lower than in the urines of matched control subjects (P less than 0.01), confirming the clinical usefulness of the test.

Calcium Oxalate↗
PubMed1977

[Infrared spectroscopy in the quantitative determination of urinary calculi constituents (author's transl)].

Infrared spectroscopy of urinary calculi can be used for the quantitative determination of the major constituents in mixed stones; the method is simple and consists in area-measurements of specific absorption peaks of the spectrum of each compound. In the area-measurement method the average error is +/- 2,5% in calcium-oxalate-apatite and +/- 2% in ammonium magnesium phosphate-carboapatite mixtures; within these limits the calculus matrix do not affect significantly the value of areas. An investigation of 64 mixed renal stones shows that in 57% of the samples, apatite is present in the nucleus; uric acid and calcium-oxalate are the most frequent superficial compounds, while the external layer of ammonium magnesium phosphate and the mixture uric acid-calcium phosphate are rare events. In calcium-oxalate-apatite and ammonium magnesium phosphate-carboapatite calculi the quantitative composition of the nucleus and the external layer differ significantly. The proposed method of analysis of internal and external structures in renal calculi can be useful for the study of etiology, for the prevention and the treatment of urolithiasis.

Humans↗
PubMedDate not supplied

Periodontal membranes from composites of hydroxyapatite and bioresorbable block copolymers.

Biomembranes are frequently proposed as devices for "guided bone regeneration." Such membranes consist generally of a thin sheet of polymeric material, mostly textured from polymeric yarns or clots, which all have a diffuse very fine winding porosity. The cross-section size of the holes of such porosity is nanometric (diameter < 0.1 microm); thus these holes can be indicated as nanoholes. Whatever the method of production, the surface density of nanoholes (number per square centimeter) has to be as high as possible. It is important also that no variation of this density occurs. The fine dimension of these microholes allows the crossing of small molecules (O2, CO2, H2O, sugars, many nutritional organic compounds and even some simple proteins) but not other larger molecules and particulates, including cells of any kind. These biomembranes have, consequently, a semipermeable behavior, providing the functional role which is the interposition of a barrier for the cells, separating the bone from the surrounding soft tissues. The kinetic of proliferation of osteoblasts is lower than that of fibroblasts. Most membranes of this kind are not resorbable. The main problem for the resorbable ones is the speed of size increase of the holes during the time. Their diameter must not exceed a threshold value until the reconstruction of bone is complete, otherwise soft tissue cells will invade the growing bone tissue with formation of undesirable mixed tissue. The present paper deals with a resorbable membrane made with a composite polymer/ceramic. A poly(epsilon-caprolactone)-block-poly(oxyethylene)-block-poly(epsilon-caprolactone) copolymer is the polymeric matrix which contains dispersed ceramic hydroxyapatite microgranules, a stiff filling additive. The main possible use is that of periodontal membranes. The copolymer, obtained by thermal polymerization of epsilon-caprolactone onto poly(ethylene-glycol), presents good biological tolerance, is resorbable under physiological conditions and can promote cell growth. Histological tests, performed 6 months after implantation, showed that the polymeric matrix is almost totally resorbed. New-formed bone colonizes even the innermost parts of the membrane, with bone trabeculae closely surrounding the hydroxyapatite granules.

Journal Article↗
PubMedDate not supplied

Vascular endothelial growth factor (VEGF) and other common tissue prognostic indicators in breast cancer: a case-control study.

VEGF is a specific mitogen and survival factor for endothelial cells and a key promoter of angiogenesis in physiological and pathological conditions. Nevertheless, VEGF tissue evaluation in cancer patients as a prognostic factor compared to the conventional histological and biological parameters is still controversial. In this case-control study, tissue VEGF was retrospectively determined by immunohistochemistry and related to T, N, ER, PgR, c-erbB-2, p53, MIB-1 and cyclin D1 in 129 breast cancer patients. Seventy-four of these patients had developed distant metastases postoperatively. The remaining 55 patients had remained disease-free >10 years after surgery. In 17 (13%) of the 129 patients (six with distant metastases and eleven disease-free) tissue and plasma VEGF were concomitantly evaluated. In univariate analysis no significant differences in VEGF and tumor size were found between metastatic and disease-free patients, whereas there were significant differences in N, ER, PgR, c-erbB-2, p53, MIB-1 and cyclin D1 (p ranging from 0.001 to 0.0001). In multivariate analysis VEGF showed less significance than N, ER, c-erbB-2, MIB-1 and cyclin D1 (p = 0.012, p = 0.007, p = 0.005, p = 0.005, p = 0.002 and p = 0.001, respectively). VEGF was a significant unfavorable prognostic indicator only in the N+ subset (p = 0.015), while ER (p = 0.05 and p = 0.021) and MIB-1 (p = 0.031 and p = 0.022) were significant in both the N+ and N- subgroups. In multivariate analysis in the 74 metastatic cases VEGF did not show any significance in relation to disease-free interval and overall survival from the time of mastectomy and from the time of relapse, whereas N and PgR did (p ranging from 0.018 to 0.001). In conclusion, tissue VEGF does not seem a suitable candidate to replace conventional histological and other common biological prognostic factors in breast cancer.

Adult↗
PubMedDate not supplied

Comparative cardiovascular effects of different progestins in menopause.

Progesterone receptors are present in the arterial wall and it is, therefore, likely that the arterial effects of progestins are mediated through progesterone receptors as well as through down-regulation of the estradiol receptor. Progestin therapy affects arterial function, as it can stabilize arteries in a state of vasomotor instability, but may also induce vasoconstriction of estrogenized vessels. Thus, the cardiovascular effects of progestins may influence the cardioprotective effect of estrogens. There has been some concern that a combined estrogen-progestogen therapy may attenuate some of estrogen's beneficial effects on cardiovascular health. This is a reflection of the past epidemiologic studies which have used primarily unopposed estrogen. The PEPI trial is the only large-scale, long-term study to compare directly the effects of different combined hormone replacement therapy regimens upon plasma lipids in healthy women. This study has shown that the adjunctive clinical impact of different progestogens on the beneficial effect of estrogen replacement therapy is trivial. It has never been proved that in normocholesterolemic women, e.g., those included in the PEPI trial, the increase in HDL reduces cardiovascular mortality or morbidity. Based on the results of PEPI, hormone replacement therapy has positive effects on key heart disease risk factors and endometrial tissue, and the magnitude of those effects does not differ significantly across the hormone replacement therapy regimens used. At present there are only few and inconclusive data available on the vascular effect of progestins in menopausal women. Some studies found that progestins reduced the beneficial effect of estrogens, while others did not. Our group has recently shown that different estrogen-progestin treatments have different effects upon vascular reactivity and that a careful selection of the progestin to be added to estrogen is of capital importance to preserve, or even enhance the positive vascular effects of estrogens. Few epidemiological studies have investigated the effect of adding a progestin to estrogen therapy upon cardiovascular mortality and morbidity, and all have suggested that hormone replacement therapy may be more effective than estrogen replacement alone in reducing cardiovascular events in primary prevention. The results of the recently published Heart and Estrogen/progestin Replacement Study (HERS) have added some critical data on the effect of hormone replacement therapy for secondary prevention in women with coronary artery disease. The study, however, is affected by several important methodological and statistical problems, which make its interpretation difficult and its conclusions useless for clinical practice. The results of the study should be evaluated with caution by physicians who give advice on hormone replacement therapy, and no woman should be taken off hormone replacement therapy because of HERS. Of importance, the results of HERS should not be used to suggest alternative forms of treatment, especially the selective estrogen receptor modulators (SERMs), for cardiovascular protection in postmenopausal women.

Adult↗
PubMedDate not supplied

The femoral distal epiphysis of ovariectomized rats as a site for studies on osteoporosis: structural and mechanical evaluations.

OBJECTIVE: To investigate in detail the mechanical and structural characteristics of cancellous bone from the femoral distal epiphysis of normal and ovariectomized rats, and to provide reference values in order to improve experimental research on osteoporosis by characterising an alternative and complementary anatomic site. METHODS: 40 female Sprague-Dawley rats (10 months old) were randomly divided into 4 groups of 10 each: baseline, ovariectomized (Ovx), sham-operated (Sham-Ovx) and sham-aged (Sham-Aged). Baseline animals were sacrificed at the beginning of the study. Ovx and Sham-Ovx animals were sacrificed 16 weeks after surgery, whereas Shamaged rats were killed when aged 14 months. Femurs were excised and densitometric, ultrasonographic, mechanical and histomorphometric analyses were performed. RESULTS: When comparing the Ovx group with the others, ultrasonographic and densitometric measurements showed significant decreases (p < 0.0005) amounting to 3-5% in the amplitude dependent speed of sound (AD-SOS) and 13-20% in the BMD, respectively. Significant decreases were also seen in the femoral condyle Max. Load (28-31%; p < 0.0005) and Elastic Modulus (19-25%; p < 0.005) in the Ovx group in comparison with the Sham-Ovx and Sham-Aged groups. Histomorphometric analysis showed a significant cancellous bone loss (p < 0.0005). Densitometric (p < 0.01), histomorphometric (p < 0.01) and mechanical (p < 0.05) parameters were correlated with AD-SOS. Among the histomorphometric parameters, stepwise regression analysis showed that the trabecular bone volume (BV/TV) and Max. Load correctly predicted AD-SOS (p < 0.0005) and BMD (p < 0.0005). CONCLUSION: The data from this study characterize osteopenia occurring in the rat distalfemur 16 weeks after ovariectomy and provide methodology and reference values forfurther investigations on osteoporosis and bone-implant osteointegration in osteopenic bone.

Absorptiometry, Photon↗