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Biomedical subjects

L Mancini

Publications and source records attributed to L Mancini.

At least 37 records · Page 2Linked to original sources
PubMed1997

Effects of nedocromil sodium on the oxidative burst of polymorphonuclear leukocytes: comparison with salbutamol.

The effects of nedocromil sodium and of salbutamol on the generation of oxygen-derived free radicals in human polymorphonuclear leukocytes (PMNs) were compared in vitro by the luminol-amplified-chemiluminescence (LACL) assay induced by both particulate (Candida albicans) and soluble formyl-methionyl-leucyl-phenylalanine (fMLP) stimulants. Inhibitory dose-effect linear regressions were observed from 10(-3) to 10(-8) M for nedocromil and salbutamol after a 3' period of incubation with either C. albicans or fMLP. There was a linear regression with nedocromil sodium after 30' incubation, but desensitization was observed with salbutamol after this longer period of incubation. The generation of oxygen-derived free radicals was significantly greater for asthmatic patients than for normal subjects; therefore antiasthmatic drugs with this inhibitory activity could be an extra pharmacological benefit in the treatment of asthmatic patients.

Albuterol↗
PubMed1997

Bioeffects of a nitric oxide donor in a human preosteoclastic cell line.

Nitric oxide is a short-lived free radical produced by different isoforms of the enzyme nitric oxide synthase. It regulates a whole range of functions in the body, but little is known about its effects on bone. Rat osteoclasts and a human preosteoclast cell line (FLG 29.1) have been shown to produce nitric oxide and to express nitric oxide synthases. In the present study we investigated the role of a nitric oxide donor, 3-morpholinosydnonimine hydrochloride, on the FLG 29.1 cells. 3-Morpholinosydnonimine hydrochloride has been shown to significantly increase IL6 production and tartrate resistant acid phosphatase activity in FLG 29.1 cells, indicating a positive modulation of osteoclast differentiation. However FLG 29.1 cell adhesion on osteoblast-like cells was significantly inhibited, suggesting an inhibition of osteoclast motility. All these results confirm the bidirectional effect of nitric oxide whose basal production is necessary in promoting osteoclast differentiation, while at high levels it is effective in inhibiting osteoclast activity.

Acid Phosphatase↗
PubMed1997

[Malignant paraganglioma of the posterior mediastinum with 27 years follow-up].

INTRODUCTION: A costovertebral paraganglioma with a long history of recurrences and metastases is reported. MATERIAL AND METHODS: The lesion is documented on histological ground and with immunocytochemistry and electron microscopy. RESULTS: The patient is a 42 year old man which presented with a 5 cm axillary mass and enlarged mediastinal lymph nodes. The former lesion has been interpreted as a metastasis of paraganglioma. The patient underwent surgery because of a costovertebral paraganglioma at the age of 19 and showed locoregional metastases and a recurrence over a period of 23 years. Twenty-seven years from removal of the primitive tumor, the patient is alive and well. All the neoplasms showed identical histological features as they were composed of neoplastic elements arranged in nests surrounded by dendritic cells. Neoplastic cells immunoreacted with anti-chromogranin antiserum whereas sustentacolar cells were positive with S-100 antiserum. DISCUSSION: The differential diagnosis between a multicentric paraganglioma a metastasis has been particularly taken into consideration. In addition, axillary tumor was distinguished from a metastatic renal cell carcinoma and melanoma. The literature regarding costovertebral paraganglioma has been also revised.

Adult↗
PubMed1996

Down-regulation of rat brain 5-HT uptake carriers after treatment with high doses of D-fenfluramine.

Male rats were treated with 10 mg/kg D-fenfluramine (DF) i.p., twice a day for 4 days. Five days later there was a strong reduction (70-100%) in the Bmax of [3H]citalopram binding and the Vmax of [3H]5-HT uptake in cortical and hippocampal synaptosomes; 2 months after the treatment these parameters were reduced by 40-70%. The effect of treatment was also evaluated in synaptosomes preloaded with [3H]5-HT, superfused and exposed for 3 min to a releasing stimulus (15 mM K+ or 0.5 microM DF). In our experimental conditions, the stimulated [3H]5-HT release is Ca(2+)-dependent and takes place only from 5-HT nerve endings. The K(+)-stimulated release was not consistently altered by the DF treatment whereas DF-stimulated [3H]5-HT release was markedly reduced, either 5 days and 2 months after the treatment. The effect of chronic DF was different from the effect of i.c.v. 5,7-DHT, a specific 5-HT neurotoxin which completely abolished the K(+)-induced release. Since the decrease of synaptosomal [3H]5-HT uptake induced by 5,7-DHT (82%) was similar to that found after chronic DF (70-80%), these data suggest that the decrease of 5-HT uptake sites induced by chronic DF is not (only) due to neurodegeneration. That chronic DF could induce a functional down-regulation of 5-HT uptake sites (i.e. decreased density per intact nerve ending) was suggested by the decrease of DF-induced release, since the releasing activity of DF is dependent on functional 5-HT uptake sites. However, due to the characteristics of our model, our results are compatible with either the absence or the presence of a concomitant, partial neurodegeneration of 5-HT nerve endings in DF-treated rats. In summary, our data indicate that after treatment with high doses of DF, the 5-HT uptake carriers undergo a long-lasting down-regulation, thus totally or partly explaining the lower [3H]citalopram binding and the lower synaptosomal [3H]5-HT uptake.

Animals↗
PubMed1996

New features of dislocation images in third-generation synchrotron radiation topographs.

Some aspects of the dislocation contrast observed at third-generation synchrotron radiation set-ups are presented. They can be explained by taking into account angular deviation effects on the beam propagation, which are visible because of the ;almost plane-wave' character of these sources. In particular, we show how the evolution of the direct image width of a dislocation as a function of the sample-to-film distance can allow a complete determination of the Burgers vector, i.e. in sign and modulus. In addition, experimental results obtained in monochromatic beam topography are compared with simulated images calculated assuming plane-wave illumination and are demonstrated to show a satisfactory agreement. The utility of the weak-beam technique in enhancing the spatial resolution is demonstrated and a criterion for the selection of experimental conditions depending upon the required spatial resolution, signal-to-noise ratio and exposure time is presented.

Journal Article↗
PubMed1996

Morphological aspects of the vascularization in intraventricular neural transplants from embryo to embryo.

Intraventricular transplants of neural tissues were performed in ovo from embryo to embryo. Fragments of the nervous wall of the optic lobe (tectum) from 14-day chick or 12-day quail embryos (donor) were inserted into the ventricle of the right optic lobe of 6-day chick or 5-day quail embryos (host). Chick-to-chick, chick-to-quail and quail-to-chick grafts were carried out. The vascularization changes occurring in the host tectum and in the grafted neural tissues were analysed under light, transmission, and scanning electron microscopes and by morphometric methods. In the host embryo tectum, the neural graft stimulates a statistically significant increment in vessel density and a vessel sprouting into the ventricle of the optic lobe. The vascular sprouts reach the transplanted tissue and establish connections with its native microvasculature. The chick-to-quail and quail-to-chick grafts, submitted to immunoreaction with a quail-specific antibody which recognizes an antigen (MB1) present on endothelial cells, indicate that re-establishment of the circulation in the graft depends upon anastomoses between host and donor vasculatures and the rapid new growth of host-derived and donor-native vessels. The presence of macrophage-like cells escorting the new-growing vessels suggests that these cells are involved in the host and donor tissue angiogenesis.

Animals↗
PubMed1996

[Analysis of the validity of vaginal-cervical cytologic examination in 162 pre- and post-menopausal patients].

The authors examine 162 cervico-vaginal smears of women in peri-menopause presenting cellular alterations (ASCUS). These patients were treated with a local topic therapy as the persistence of these alterations in 23 cases (14.2%) second level analyses were performed: gynecological visit, colposcopy and biopsy. In addition to inflammatory aspects 2 in situ carcinomas and 2 moderate dysplasias were recorded. We believe therefore that cytology could be a valid aid also in pre-menopausal women in the cervico-vaginal pathology.

Age Factors↗
PubMed1995

Pachydermoperiostosis: dermatological, neurological and radiological observations.

A case of pachydermoperiostosis is described. Interesting features were the presence of carpal and tarsal tunnel syndromes, chronic leg ulcerations and large calcification of the Achilles tendon. Neurological alterations were explained by the stenosis of the tunnels secondary to the periosteal apposition. Chronic leg ulcerations were probably due to neurological and circulatory alterations.

Adult↗
PubMed1993

Perivascular astrocytes and endothelium in the development of the blood-brain barrier in the optic tectum of the chick embryo.

The role played by perivascular astrocytes in neural vessel maturation was investigated in microvessels of the chick embryo optic tectum. Three-dimensional reconstructions and quantitative analyses were made, and permeability was studied. On embryonic days 14-16, 12.5% of the microvessel wall is surrounded by astrocyte endfeet which, in most cases (82%), are located under endothelium junctions; the latter, at this stage, partly prevent the extravascular escape of the marker horseradish peroxidase. On days 18-21, the astrocyte processes form a nearly complete perivascular sheath enveloping 96% of the microvessel perimeter; the junctions of the endothelial cells are much wider and impermeable owing to extensive fusion of the endothelial plasma membranes. This investigation suggests a close relationship between the perivascular arrangement of glia and differentiation of the endothelium tight junctions and indicates that the morphofunctional maturation of the latter takes place progressively during the prenatal organogenesis of the chick central nervous system.

Animals↗
PubMed1993

Central nervous system imaging in reevaluation of patients with neurofibromatosis type 1.

We report the results of the reevaluation of 24 patients with neurofibromatosis type 1 (NF1) using central nervous system (CNS) imaging techniques. The first examination by computed tomography (CT) or magnetic resonance imaging (MRI) indicated the presence of optic glioma in three cases, "unidentified bright objects" (UBOs) in six, and a suspected right frontal tumor in one. In two patients optic glioma and UBOs were both present and in one of them a bulbar tumor was also suspected. Later imaging examinations revealed the appearance of optic glioma in three more cases and UBOs in nine. In two of these patients both optic glioma and UBOs were present. This study indicates that the likelihood of detecting imaging abnormalities in patients with NF1 increases when systematic follow-up is performed. Optic gliomas are characteristic of pediatric patients; they rarely give rise to clinical manifestations (1/6 cases) and in general progress very slowly. For these reasons, therapeutic strategy must be carefully considered and individually decided. UBOs are very frequent findings in pediatric patients with NF 1 and therefore they must be considered diagnostically relevant. They are not related to clinical manifestations and spontaneous regression has been observed. The nature of these imaging abnormalities is still unknown, but because they do not behave like tumors, useless and dangerous therapeutic procedures should not be employed.

Adolescent↗
PubMed1993

Relationship between café-au-lait spots as the only symptom and peripheral neurofibromatosis (NF1): a follow-up study.

We re-examined 21 children with the possible diagnosis of peripheral neurofibromatosis (NF1) based on the presence of café-au-lait (CAL) spots as the single clinical finding. We evaluated whether "typical" or "atypical" appearance of the spots was important for the final diagnosis and whether the co-existence of other non-specific signs (e.g. pectus excavatum) were of any significance for the final diagnosis. In 8/14 (57.1%) cases with "typical" CAL spots, the diagnosis of NF1 was finally established on the basis of other criteria. For the other 6 patients the diagnosis is not yet definitive but highly probable on the basis of the presence of macrocephaly, pectus excavatum and/or MRI findings. Only one patient among five with "atypical" CAL spots possibly has NF1.

Brain Neoplasms↗
PubMed1992

Lower limb arterio-venous shunts, autonomic neuropathy and diabetic foot.

We have quantitatively assessed the percentage of lower limb arterio-venous (a-v) shunting using a radioisotopic technique and correlated it with autonomic neuropathy evaluated by cardiovascular tests. We have studied three groups of diabetic patients: Group A, 12 non-neuropathic subjects without foot lesions; Group B, 12 neuropathic subjects without foot lesions; Group C, 12 neuropathic subjects with recurrent foot ulcers. Shunting was higher in Group C (10.4 +/- 2.7%) than in Group B (6.8 +/- 2.3%, P less than 0.01) and Group A (3.8 +/- 1.2%, P less than 0.001). Shunts in Group B were higher than in Group A (P less than 0.05). All the tests exploring autonomic function were more impaired in Groups B and C than in Group A, with no difference between Groups B and C. A direct correlation was found between a-v shunting and the following cardiovascular tests: postural hypotension (PH) (r = 0.41, P less than 0.02), sustained handgrip (SH) (r = 0.56, P less than 0.001), deep breathing (DB) (r = 0.40, P less than 0.005) and lying to standing (LS) (r = 0.44, P less than 0.01). A positive correlation was also found between a-v shunts and duration of the disease (r = 0.62, P less than 0.001). Arterio-venous shunting was found to be directly related to autonomic neuropathy even if the higher shunting found in the patients with foot ulcers was not related to a higher degree of autonomic involvement; in addition, this group of patients was characterized by having a more advanced sensory and motor neuropathy. In conclusion, autonomic neuropathy, through its influence on a-v shunts, may play a role in the pathogenesis of diabetic foot, but peripheral neuropathy probably plays a key role in conditioning the development of the overt clinical manifestations of diabetic foot.

Albuminuria↗
PubMed1992

Permeability-related structures in developing and mature microvessels of the chicken optic tectum.

The mode and the temporal sequence of the modifications undergone by permeability-related structures in the neural microvessels have been ultrastructurally and morphometrically investigated in optic tecta of 6, 14, and 18 incubation day (i.d.) chicken embryos and of 30 day chickens. Horseradish peroxidase was utilized as a permeability marker. The endo- and exocytosis-related structures (vesicles and vacuoles) and the interendothelial junctions remarkably change during development: the density of the vacuoles is decreased at the 14th i.d., while that of the vesicles becomes significantly low at the 18th i.d., both reaching lowest values in the chicken; the passage of the marker through the endothelial junctions begins to be hindered from the 14th i.d., parallel to the perivascular arrangement of astrocytic glia endfeet, and it is completely blocked at hatching time. The findings suggest that the optic tectum microvessels are permeable, and thus immature, in the early development and progressively acquire morphofunctional features of vessels provided with barrier devices during the pre- and post-natal development of the brain.

Animals↗
PubMed1992

Effect of calcitonin or the anabolic steroid Decadurabolin on serum beta 2 microglobulin in osteoporotic postmenopausal women.

beta 2-Microglobulin (beta 2m) is a small polypeptide of 99 amino acids with a molecular weight of 11.800. It is found in serum, on the surface of almost all mammalian cells and is part of the surface antigen of the cell membrane of human lymphocytes. Moreover, the heavy chain of major histocompatibility complex class I molecules normally associates in the membrane with beta 2m. According to Canalis, et al this polypeptide is a bone derived growth factor. In our study, serum beta 2m, osteocalcin bone Gla-protein (BGP) and calcium phosphorous metabolism were evaluated in a group of 18 osteoporotic women. Nine were treated with an anabolic steroid, DecaDurabolin and 9 with salmon calcitonin (sCT) for 3 months. The same variables were evaluated in a control group (6 osteoporotic women) treated with oral Ca (1,500 mg/day for 3 months). A significant increase in serum beta 2m and BGP (p < 0.001) was observed after anabolic steroid while a significant decrease in serum beta 2m and BGP (p < 0.01) was observed after sCT. No significant variation for serum beta 2m and BGP was observed in the control group. No significant variation of calcium-phosphorous metabolism was observed in either the control group or the treated group. BGP variations suggest that anabolic steroid stimulates bone formation while a decrease in BGP observed after sCT suggests that this hormone depresses bone turnover via a block in osteoclast activity. Moreover it could be suggested that anabolic steroid and sCT affect beta 2m producing cells.

Aged↗
PubMed1991

The importance of vitamin C for hydroxylation of vitamin D3 to 1,25(OH)2D3 in man.

The effects of vitamin C on 1,25(OH)2D3 synthesis in humans were evaluated; the study included 20 females. They were divided into 2 groups. The first of the 10 subjects (age range 55-71) received ascorbic acid at a dose of 150 mg/die i.v. for 10 days; the second 10 subjects (age range 55-69) received a placebo i.v. for 10 days. In a later study (after a 30-day washout) the same two groups were tested for the second time with ascorbic acid at a dose of 1,000 mg/die i.v. for 10 days and placebo i.v. for 10 days. Serum calcium and phosphorus, serum Ca++, serum proteins, blood and urinary pH, serum 25(OH)D3 and 1,25(OH)2D3, serum PTH, urinary hydroxyprolin were tested before and after the treatments. In the first study a significant increase in serum 1,25(OH)2D3 was observed after ascorbic acid while no significant variation was observed for the other parameters. In the second study, a significant increase in serum Ca++ and a significant decrease in serum 1,25(OH)2D3 were observed after ascorbic acid while no significant variation was observed for the other parameters. The authors conclude that ascorbic acid promotes 1,25(OH)2D3 synthesis at a paraphysiologic dose (150 mg/die) in humans but this synthesis is inhibited at higher doses (1,000 mg/die). The latter effect by Ca++ or by an effect of ascorbate on 1 alpha-hydroxylase enzyme could be mediated.

Adult↗
PubMed1991

The effects of long-term hypoxia on epicardium and myocardium in developing chick embryo hearts.

The consequences of long-term O2 deprivation on heart development were analyzed morphometrically and ultrastructurally, utilizing the hearts of chicken embryos developed under hypoxia from the 3rd to the 18th incubation day. The results indicate that embryos kept under low O2 blood tension do not show disturbances in heart morphohistogenesis, but are characterized by a thicker epicardium and a thinner myocardium than the controls; moreover, both the number and calibre of the heart microvessels are increased. The thickening of the epicardium is due to hyperplasia of the mesothelial cells, increment in calibre of the submesothelial vessels, and to conspicuous perivascular infiltration of blood-derived cells. The thinning of the cardiac muscle seems to be dependent on myocardiocyte hypotrophy and myofibril reduction. The increase in the volume density of myocardium vessels, due to their dilatation and proliferation, may be considered expression of a vascular adaptive reaction to low oxygen tissue concentration.

Animals↗
PubMed1991

Gastric emptying rate and hormonal response in type II diabetics.

Gastric emptying time was measured by ultrasonography in 18 NIDDM patients with and without autonomic neuropathy, evaluated by cardiovascular autonomic tests and in 10 controls before and after a physiologic test meal. Six neuropathic subjects showed gastrointestinal symptoms such as fullness and early satiety. Blood glucose, gastrin and pancreatic polypeptide were evaluated before and up to 200 min after the test meal. The gastric emptying rate was similar in controls (275 +/- 45 min) and in diabetic patients without (260 +/- 49 min) and with autonomic neuropathy (257 +/- 48 min) (p = ns), while diabetic symptomatics showed a significant reduction of gastric emptying rate (420 +/- 19.7 min) (p less than 0.001). Basal serum glucose concentration was similar in all diabetic patients (132 +/- 18 mg/dl, 166 +/- 52 mg/dl, 161 +/- 61 mg/dl, p = ns). A basal value of serum gastrin was similar in all groups while the test meal produced a rise with a peak at 40' significantly higher only in symptomatics (195 +/- 58 pg/ml vs control 107 +/- 88 pg/ml, diabetics without and with autonomic neuropathy: 98 +/- 12 pg/ml and 88 +/- 22 pg/ml respectively; p less than 0.01). Basal and stimulated PP values were similar in all groups. In conclusion ultrasonography is a simple, reliable method to evaluate gastric emptying rate without any interference in the mechanism of digestion and absorption of nutrients. The presence of non specific symptoms, such as nausea and gastric fullness, may indicate an early gastric involvement as supported by sonographic evidence of impaired emptying.

Adult↗