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M Mattioli

Publications and source records attributed to M Mattioli.

At least 55 records · Page 3Linked to original sources
PubMed1996

Genetic hemochromatosis in Italian patients with porphyria cutanea tarda: possible explanation for iron overload.

BACKGROUND/AIMS: Mild to moderate iron overload is found in most patients with porphyria cutanea tarda. This study aimed to evaluate whether iron overload in patients with porphyria cutanea tarda is related to the presence of a coexistent genetic hemochromatosis gene. METHODS: A cohort study of 94 Italian patients with porphyria cutanea tarda (90 men and 4 women) and 20 relatives of five patients with iron overload were studied. Diagnosis of iron overload was assessed by transferrin saturation, serum ferritin and iron removed by phlebotomy to reach depletion. HLA typing by microlymphocytotoxicity test and duodenal ferritin analysis by immunohistochemistry were performed in a smaller number of patients. The chi square test was used to compare means and prevalences. RESULTS: Iron overload was present in 62% of the patients. HLA-A3 prevalence was significantly higher (p < 0.01) in subjects with iron overload than in those without. A lack of duodenal ferritin was observed in 14/18 patients with and in 6/12 without iron overload. Family studies showed the presence of iron overload but not of porphyria cutanea tarda in HLA identical or semi-identical relatives of the patients. CONCLUSIONS: Italian patients with porphyria cutanea tarda and iron overload appear to have one or even two genes for genetic hemochromatosis.

Adult↗
PubMed1996

Activation of protein kinase A and protein kinase C mediates the depolarising effect of LH in ovine cumulus-corona cells.

We have studied the changes in membrane potential induced by LH in cumulus and granulosa cells isolated from sheep antral follicles. The investigation was carried out by using a non-invasive technique based on the use of a membrane potential sensitive probe, bis-oxonol. The membrane potential of mural granulosa cells was totally unaffected by LH, while that of cumulus or corona cells showed a marked depolarisation, starting 2-3 min after the addition of the hormone and plateauing after 5-10 min. None of the cells tested reacted to FSH. In the second part of the experiment the role of protein kinase A (PKA) and protein kinase C (PKC) in mediating the effect of LH was studied. The selective activation of PKA or PKC induced in cumulus-corona cells a rapid hyperpolarisation due to increased Cl and K conductance respectively. By contrast, the simultaneous activation of the two kinases induced a rapid membrane depolarisation due to the progressive decrease in K conductance. The activation of each kinase or their combined stimulation did not induce any change in the membrane potential of mural granulosa cells. These data demonstrated that LH has a depolarising effect regionally circumscribed to cumulus-corona cells and that this depolarisation depends on a reduction of K conductance caused by the activation of PKA and PKC.

Animals↗
PubMed1995

Venous angiomas: plain and contrast-enhanced MRI and MR angiography.

We studied 17 patients with venous angiomas, 4 of whom had associated cavernous angiomas. All underwent MRI with spin-echo T1- and T2-weighted images and T1-weighted images after Gd-DTPA; MR angiography (MRA) was also performed with 3D and 2D time-of-flight technique; 5 patients underwent conventional angiography. Contrast-enhanced MRI demonstrated all the lesions, showing the peripheral medullary veins, the collector and the type of drainage. Both 3D and 2D MRA provided diagnostic information identical to that obtained after infusion of Gd-DTPA. Contrast-enhanced were T1-weighted images and MRA superior in all the cases to images without gadolinium. The possible association with cavernous angiomas (24% in our study) indicates T2-weighted imaging.

Adolescent↗
PubMed1995

Influence of progesterone on boar sperm capacitation.

This research investigates the effect of progesterone (P4) on boar sperm capacitation. Ejaculated spermatozoa were washed and incubated under capacitating conditions with or without P4. At different times of incubation samples of sperm were exposed to solubilized zonae pellucidae (ZP) and the degree of capacitation was evaluated by the incidence of zona-induced acrosome reaction (AR). The status of the acrosome was studied by using an FITC-conjugated lectin (Pisum sativum agglutinin; FITC-PSA). The effect of P4 on the fertilizing ability of semen was then evaluated in an in vitro fertilization system by exposing in vitro matured oocytes to sperm preincubated for 2 or 4 h with or without P4, under capacitating conditions. PSA staining showed that P4 does not affect the incidence of spontaneous AR. By contrast, spermatozoa incubated with P4 showed a higher percentage of AR than controls after the exposure to solubilized ZP. This enhanced reactivity to ZP suggests a direct effect of P4 on sperm capacitation. The in vitro fertilization assay was consistent with these results demonstrating a higher fertilizing ability in sperm preincubated with P4 than in controls while the steroid was without effect when added only during the fertilization step. These results demonstrate that P4 improves the fertilizing ability of boar semen essentially by facilitating the process of capacitation.

Acrosome↗
PubMed1995

POEMS syndrome in a female Italian patient. A case report.

POEMS syndrome is an uncommon association of polyneuropathy, organomegaly (liver, spleen, lymph nodes), endocrinopathy (hypogonadism primary hypothyroidism, diabetes mellitus, adrenal insufficiency), monoclonal gammopathy and skin changes; bone lesions (generally osteosclerotic, less frequently osteolytic or mixed) are nearly always present in this multisystem disease. We describe the first case of a female Italian patient with POEMS syndrome. Therapy with prednisone was of scant benefit and the patient died of cardiogenic shock some days after temporary pacemaker implantation, performed for recurrent episodes of bradycardia. From the beginning of steroid therapy she survived about fifteen months.

Anti-Inflammatory Agents↗
PubMed1994

Concentration of cyclic AMP during the maturation of pig oocytes in vivo and in vitro.

Intracellular concentrations of cyclic AMP (cAMP) were measured in pig oocytes maturing in vivo or in vitro. Maturation in vivo was induced with 500 iu hCG administered to gilts treated with pregnant mares' serum gonadotrophin (PMSG). Although PMSG did not affect cAMP concentrations (basal values, 1.69 +/- 0.28 fmol per oocyte), hCG induced a transient rise (8.86 +/- 1.15 fmol per oocyte 12 h after hCG injection). Similarly, the cAMP concentration rose in oocytes maturing in vitro if the oocytes (surrounded or not by cumulus cells) were co-cultured with the follicle wall in the presence of LH. The same increase in cAMP was obtained when denuded oocytes were co-cultured with mural granulosa cells. Theca cells exhibited only a moderate activity, while cumulus cells were totally ineffective. Granulosa cells exposed to LH lost their stimulating influence after 24 h of culture. In the presence of FSH, cAMP production by the oocyte was unaffected by any type of follicle cell. The role of cAMP in the control of oocyte maturation was investigated using dibutyryl cAMP. The presence of dibutyryl cAMP prevented the resumption of meiosis in a dose-dependent manner, but when it was present during the first 12 h of culture only, meiotic progression was accelerated (0 versus 47% of oocytes had germinal vesicles in groups treated with dibutyryl cAMP and control groups, respectively, after 24 h of culture).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

T stages of tumors of the tongue and floor of the mouth: correlation between MR with gadopentetate dimeglumine and pathologic data.

PURPOSE: To define MR accuracy in the evaluation of the T stages of tumors of the tongue and floor of the mouth. METHODS: Fifty-two patients affected by squamous cell carcinoma were studied with a superconductive system at 1.5 T. The study was performed with spin-echo T1- and T2-weighted images before contrast and short spin-echo T1-weighted and gradient-echo sequences after gadopentetate dimeglumine administration. The results obtained with MR were compared with pathologic data. RESULTS: Good correlation of T stages (TNM system) was obtained in 45 of 52 cases. MR did not show four superficial lesions. In one case, infiltration of the cortical bone of the mandible was not demonstrated (MR, T2; pathologic, T4), and in another the lesion was classified as T2 instead of T3, as it was pathologically. One lesion was classified as T4 on MR because of infiltration of the alveolar ridge but was classified as T2 at surgery. In 46 patients who underwent surgery, the accuracy of MR was excellent for predicting the relationship of tumor to midline and oral floor musculature. The results obtained with gadopentetate dimeglumine were better than those obtained in noncontrast studies in 32 (62%) of 53 cases. CONCLUSION: MR showed high accuracy in the study of tumors of the tongue and floor of the mouth.

Adolescent↗
PubMed1994

[The magnetic resonance estimation of the T parameter in the staging of tumors of the oral cavity and tongue. A correlation with postoperative data and preliminary echotomographic experience].

Fifty-three patients with oral cavity and tongue tumors were studied with MRI, 18 with CT and 10 with US. MR results were compared with postoperative and clinical results relative to the T variable of the TNM classification of oral cavity tumors. MRI demonstrated 51 of 53 tumors; it was in agreement with surgery, relative to T, in 43 of 48 cases and with clinics in 5 of 5 cases. In 5 patients MRI understaged: two lesions were classified as T0 because the tumors developed on the surface (p T4, for alveolar ridge infiltration). Moreover, MRI staged another lesion as T2 instead of T3 because of its superficial component, while in 2 cases the infiltration of the cortical bone of the jaw was not demonstrated (T1 at MRI, T4 at p; T2 at MRI, T4 at p). MRI was reliable enough to evaluate the relationships between the lesions and the surrounding structures but it was limited in demonstrating superficial lesions and in evaluating the infiltration of the alveolar ridge and of the cortical bone of the jaw in the early stage. The use of gadolinium proved to be especially useful for the exact definition of the size of the lesions and of their relationships with the surrounding structures. CT proved better than MRI to evaluate bone involvement in one case, even though neither technique could identify bone involvement in another patient. US yielded accurate information on the presence of lesions, their size and relationships with midline and floor of the mouth muscles, while its demonstration of the relationships between tumors and bone structures was poor, especially relative to tumor spread outside the oral cavity.

Adolescent↗
PubMed1993

Actin polymerization in boar spermatozoa: fertilization is reduced with use of cytochalasin D.

The aggregational state of actin in boar spermatozoa after capacitation and the acrosome reaction has been examined by several methods. In vitro fertilization (IVF) experiments were conducted in the presence and absence of cytochalasin D (CD) to evaluate the role of actin polymerization in the events of fertilization. The fertilizing capacity was very high in controls, but, when CD (an inhibitor of the polymerization of actin) was added to the capacitation medium, there was a marked decrease in the fertilizing capacity of the boar spermatozoa. There was a further decrease when CD was present during both capacitation and fertilization processes. In addition to the IVF tests, biochemical and immunoelectron microscopic methods were used to analyze the state of aggregation of actin in boar spermatozoa after capacitation, and the acrosome reaction. By immunoelectron microscopy with a phalloidin probe, there were no gold particles, indicating the presence of F-actin on boar sperm heads capacitated and acrosome-reacted in media containing CD. By sodium dodecyl sulfate-polyacrylamide gel electrophoresis there were differences in NP-40 solubility, reflecting actin polymerization, between CD-treated and untreated sperm. These results suggest that actin polymerizes during capacitation and the acrosome reaction and that this polymerization is essential to the fertilization process.

Acrosome↗
PubMed1993

Calcium and potassium currents in porcine granulosa cells maintained in follicular or monolayer tissue culture.

We studied membrane currents in granulosa cells (GC), immediately after collection or after variable culture time in the everted-follicle wall or in the monolayer. GC in both systems express an inward calcium current (ICa) with T-type kinetics and voltage dependence. GC in the everted-follicle culture express an outward potassium current (IK) kinetics, which remains unchanged during three days in culture. IK has delayed-rectifier kinetics, but is insensitive to TEA, 4-AP and apamine. GC in monolayer culture develop a new, inactivating delayed-rectifier potassium current (InK), which progressively dominates as cells advance from day one to day three in culture. A similar InK was recorded in large luteal cells. A possible link between luteinization and the appearance of InK is hypothesized.

Animals↗
PubMed1993

Osmotic and cytotoxic study of vitrification of immature bovine oocytes.

Four experiments were conducted to determine the composition of a solution suitable for vitrification of immature bovine oocytes. The osmotic and cytotoxic effect of different concentrations (0, 0.25, 0.5 and 1 mol l-1) of nonpermeating solutes (sucrose versus trehalose) were examined. In addition, the effect of permeating cryoprotectants such as glycerol, dimethyl sulfoxide, and propylene glycol (40% w/v) on the viability of oocytes was studied to determine the optimal time of exposure and the most suitable cryoprotectant. Exposure of bovine oocytes to trehalose was less harmful than exposure to sucrose (P < 0.01), and high normospermic fertilization (70%) was achieved after exposure to 0.25 mol trehalose l-1. Propylene glycol was chosen as the cryoprotectant for the vitrification of immature bovine oocytes because of its fast permeating rate and its low cytotoxic effect. The composition of this solution (40% propylene glycol and 0.25 mol trehalose l-1 in PBS containing 4% w/v BSA) appeared to be suitable for vitrification, as the fertilization rate of the vitrified oocytes was 37% (36 of 97).

Animals↗
PubMed1992

Inhibition of Ca2+ and K+ currents by "antifreeze" proteins.

For the last two decades, the research on fish "antifreeze" proteins has focused exclusively on their ability to depress noncolligatively blood plasma freezing points, presumably by binding to ice crystals. We report evidence that antifreeze polypeptides from the winter flounder (Pseudopleuronectes americanus) have another special property, the ability to block ion channels. In experiments with porcine granulosa cells we show, using the patch-clamp technique in the whole cell configuration, that these proteins suppress effectively calcium and potassium currents. The results of dose-response studies indicate a protein-protein interaction mechanism.

Animals↗
PubMed1992

[Oral contrast media in the study of the esophagus with magnetic resonance. Proposal of a new preparation].

The major problem in MRI of the esophagus is the lack of a reliable oral contrast agent. To determine the value of Gd-DTPA as an oral contrast medium for the esophagus as a part of phase III clinical trial, 17 patients (10 esophageal neoplasms, 4 neoplasms of the pharyngo-laryngeal tract, 3 Zenker's diverticula) underwent MRI. The oral contrast medium is proposed in a new preparation: 5 cc of oral Gd-DTPA were emulsionated with 30 g of a low-density barium paste for esophageal CT (3% p/v). High signal intensity in the esophageal lumen was observed in all patients and in all sequences. In neoplastic lesions, the c.m. improved the definition of both the level of stenosis and the longitudinal extent of the lesion. In diverticula, the real and the false lumen could be demonstrated. In one patient the exam could not be completed. No adverse reactions were observed.

Administration, Oral↗
PubMed1992

[Magnetic resonance angiography in the study of abdominal neoplasms. Preliminary experience].

This study was designed to evaluate MRA imaging as a potential non-invasive method to study vascular infiltration in patients with abdominal neoplasms. Forty-three patients with abdominal tumors proven by CT and/or MRI were examined with MRA and subsequently with angiography. Of 15 cases of liver tumor, MRA allowed poor intratumoral vascularization to be demonstrated in 1 patient only, but it always provided a characteristic sign--i.e., the complete absence of flow in the hepatic segments infiltrated by the tumor and the evidence of pericapsular neovascularization. In 8 cases portal vein involvement was observed (4 cases of compression/dislocation, 2 cases of infiltration and 2 of thrombosis). In all cases MRA allowed the relationship between tumor and venous structures to be evaluated. It also demonstrated collateral vessel formations in 8 patients with cancrocirrhosis. Two cases of thrombosis and 3 infiltrations of the vena cava were demonstrated. Neither hepatic artery nor intrahepatic arterial vascularization could be correctly evaluated. Of 10 cases of renal tumors and in 3 of adrenal tumors, renal vein infiltration was seen in 4 cases and compression in 3, with only 1 false-positive finding. In these patients and in those with retroperitoneal masses, MRA provided valuable information on the relationship between tumor and vascular structures and was useful in detecting collateral vessels. In our experience, MRA is to be considered as a complementary technique to be performed after CT or MRI when additional information is needed as to the relationship between tumor and vascular structures. In the preoperative evaluation of abdominal neoplasm, angiography remains the gold standard, in spite of its invasiveness.

Abdominal Neoplasms↗
PubMed1991

Follicle somatic cells influence pig oocyte penetrability and cortical granule distribution.

The influence of somatic cells on oocyte penetrability was studied during in vitro maturation. Four experiments were carried out. In the first, pig oocytes were fertilized in vitro immediately after collection (immature oocytes) or after being cultured for 44 hr with cumulus cells connected to the whole wall of the extroverted follicle (follicle oocytes) or without cumulus cells (denuded oocytes) (Mattioli et al.: Gamete Res 20:177-183, 1988a). In follicle and immature oocytes, 12 hr after insemination, the sperm were equally distributed between zona and ooplasm; in denuded oocytes, the majority (90.5%) of the sperm were located in the zona. In the second experiment, zonae pellucidae of follicle and denuded oocytes, obtained after 44 hr of culture, were incubated with a sperm suspension for 2 hr at 39 degrees C to evaluate the zona binding. The different number of sperm found on the zona pellucida of follicle or denuded oocytes (49.3 +/- 2.97 vs. 37.8 +/- 1.77) did not achieve statistical significance (P greater than 0.05). In the third experiment, follicle and denuded oocytes were denuded of their zonae after maturation and then fertilized in vitro. The number of sperm recorded in the ooplasm of zona-free follicle oocytes was significantly higher than that recorded in zona-free denuded oocytes (9.2 +/- 0.93 vs 1.19 +/- 0.28) (P less than 0.01). In the last experiment the influence of somatic cells on the distribution of cortical granules was evaluated. Pig oocytes were denuded at different stages of culture and, after completion of maturation, processed for electron microscopy.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Changes in maturation-promoting activity in the cytoplasm of pig oocytes throughout maturation.

Maturation-promoting factor (MPF) was examined in maturing pig oocytes by electrofusing them with germinal vesicle (GV) oocytes. Oocytes containing high levels of MPF (MI or MII stages) induced the breakdown of the GV introduced by fusion and the formation of the metaphase plate in 1 hr. A similar effect was seen when two or three GV oocytes were fused with a MII oocyte and then incubated for 1 hr in the presence of cycloheximide (a specific protein synthesis inhibitor), indicating that high levels of preformed MPF are present at the metaphase stage. During the maturation in vitro of cumulus-enclosed oocytes, a first sharp rise in MPF was seen between 26 and 29 hr of culture (MI stage); MPF declined after 2 hr (AI-TI stages) and again reached high levels at 35 hr, where it remained for the rest of maturation. Denuded oocytes showed a similar behavior, but MPF appeared 9 hr earlier and the rise, due to the asynchronous maturation of these oocytes, was not as sharp as in cumulus enclosed oocytes. Cycloheximide was used to study protein synthesis requirements for oocyte maturation. Intact GV were observed after 44 hr of culture when cycloheximide was added at 26 hr or earlier, and chromosome decondensation and pronuclear formation were observed when the drug was added at 32 hr. Transcriptional requirements were investigated by treating the oocytes with alpha-amanitin, an RNA polymerase inhibitor. This drug could completely inhibit the maturation of cumulus-enclosed oocytes, but this was a somatic cell-mediated effect since denuded oocytes were insensitive to this treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Effects of LH and FSH on the maturation of pig oocytes in vitro.

This research was designed to investigate the effects of LH and FSH (50 ng/ml) on pig oocyte maturation in vitro. The following parameters were studied: a) the degree of heterologous coupling between cumulus cells and oocytes, evaluated by measuring the 3H-uridine and 3H-choline uptake in cumulus enclosed oocytes; b) meiotic maturation; c) cytoplasmatic maturation, evaluated by analyzing the ability of the oocytes to promote male pronucleus formation after in vitro fertilization. Despite the marked cumuli expansion induced by gonadotropins, uridine uptake was not influenced by LH or FSH. By contrast, choline uptake in LH-treated oocytes was significantly higher than in FSH-treated or control oocytes (3199 cpm+/-251 vs 1686 cpm+/-142, P<0.01). Gonadotropins accelerated meiotic progression, and after 30 hours of culture the percentage of oocytes at the germinal vesicle stage was significantly lower (P<0.01) in LH-(24%, 24/102) and FSH-(20%, 18/90) treated oocytes than in control oocytes (76%, 64/84). After 44 hours of culture, the percentage of oocytes reaching the MII stage was significantly higher (P<0.01) in the presence of LH (76%, 92/120) and FSH (86%, 92/108) than in the controls (35%, 40/116). The percentage of oocytes capable of sustaining male pronucleus formation was similar in the control (48.4%, 63/132) and FSH-treated oocytes (44.3%, 51/116), while it was markedly increased (P<0.01) by the addition of LH (72.7%, 143/197). The data reported indicate that in vitro pig oocytes tend to undergo meiotic maturation even in the absence of hormones. However, in our in vitro system, LH and FSH accelerated and facilitated meiotic progression, and LH selectively improved cytoplasmic maturation which is required to promote the formation of a male pronucleus.

Journal Article↗