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G Rispoli

Publications and source records attributed to G Rispoli.

35 records · Page 2Linked to original sources
PubMed1992

The influence of arrestin (48K protein) and rhodopsin kinase on visual transduction.

The shutoff of the phototransduction cascade in retinal rods requires the inactivation of light-activated rhodopsin. The underlying mechanisms were studied in functionally intact detached rod outer segments by testing the effect of either sangivamycin, an inhibitor of rhodopsin kinase, or phytic acid, an inhibitor of 48K protein binding to phosphorylated rhodopsin, on light responses recorded in whole-cell voltage clamp. The results suggest that isomerized rhodopsin is inactivated fully by multiple phosphorylation and that the binding of 48K protein accelerates recovery by quenching partially phosphorylated rhodopsin. Higher concentrations of sangivamycin cause changes in the light response that cannot be explained by selective inhibition of rhodopsin kinase and suggest that other protein kinases are needed for normal rod function.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed1992

The influence of some prognostic factors on the clinical outcome of patients with squamous cell carcinoma of the vulva.

The present paper examined the influence of patient age, surgical T stage, tumor size, tumor differentiation and lymphnodal status on the clinical outcome of 29 patients with primary vulvar squamous cell carcinoma treated with radical surgery. Eighteen patients underwent radical vulvectomy with bilateral inguinal-femoral lymphadenectomy alone; 10 patients had additional bilateral pelvic lymphadenectomy; another patient had additional bilateral pelvic lymphadenectomy and anterior pelvic exenteration for a carcinoma of the clitoris involving the urethra. Nine patients developed relapsing disease; the site of recurrence was local in 4 patients, inguinal in 2, both local and inguinal in one patient, pelvic in one, both pelvic and distant in one. Eight recurrences occurred within 24 months from surgery; another patient developed an inguinal recurrence 45 months after operation. The actuarial 5-year disease-free survival rates were as follows: 64% for patients younger than 70 years and 63% for patients 70 years of age or older (p = not significant); 79% for patients with surgical T1-T2 stage disease and 30% for those with surgical T3 stage disease (p = 0.01); 88% for patients with tumor size less than 3 cm and 31% for those with tumor size greater than 3 cm (p less than 0.001); 66% for patients with well or moderately differentiated tumor and 51% for those with poorly differentiated tumor (p = not significant); 82% for patients with negative groin lymph nodes and 39% for those with positive groin lymph nodes (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Comparison of tumor-associated trypsin inhibitor (TATI) with CA125 as a marker for diagnosis and monitoring of epithelial ovarian cancer.

Preoperative serum levels of CA125 and tumor-associated trypsin inhibitor (TATI) were measured in 220 patients undergoing laparotomy for adnexal masses. Of the 57 patients with epithelial ovarian cancer. 86% had serum CA125 higher than 35 kU/l and 81% higher than 65 kU/l while 51% had serum TATI above 22 micrograms/l. In eight patients with mucinous ovarian malignancies, serum levels of CA125 were above 65 kU/l in 6 cases while serum TATI was above 22 micrograms/l in 4 cases. Of the 163 patients with benign ovarian masses, 41% had serum CA125 levels above 65 kU/l and 17% above 65 kU/l whereas serum TATI was above 22 micrograms/l in 6%. In 11 cancer patients having elevated levels of both CA125 and TATI at diagnosis, the serum concentrations of these antigens were periodically measured during and after treatment. Changes in CA125 and TATI levels correlated with the clinical course in 84% and 37% of the instances, respectively. After the sixth course of chemotherapy, the diagnostic accuracy of the markers in the evaluation of the disease status at second-look laparotomy was 55% for CA125 with a cut-off level of 35 kU/l, 36% for a cut-off level of 65 kU/l, 55% for TATI, and 66% for the combination of CA125 and TATI with cut-off levels of 65 kU/l and 22 micrograms/l. CA125 is the most sensitive marker for epithelial ovarian cancer, but the concomitant measurement of TATI could be of benefit in both differential diagnosis of adnexal masses and monitoring of response of epithelial ovarian cancer to treatment.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1990

CAM26, CAM29 and mucin-like carcinoma associated antigen in epithelial ovarian cancer.

The levels of CA125 (reference values [RVs] 35 U/mL and 65 U/mL), CA15.3 (RV = 32 U/mL), Mucin-like carcinoma associated antigen (MCA; RV = 15 U/mL), CAM26 (RV = 75 U/mL) and CAM29 (RV = 15 U/mL) were preoperatively assayed in blood samples drawn from 42 patients with ovarian carcinoma and 101 patients with benign ovarian pathology undergoing laparotomy at the Department of Gynecology and Obstetrics of the University of Pisa. With 65 U/mL as RV, CA125 had a sensitivity (SE) of 80.9% and a specificity (SP) of 89.1% for ovarian carcinoma; with 35 U/mL as RV, CA125 had a SE of 85.7% and a SP of 66.3%; CA15.3 had a SE of 57.1% and a SP of 96.0%; MCA had a SE of 59.5% and a SP 86.1%; CAM26 had a SE of 21.4% and a SP of 96.0%, CAM29 had a SE of 64.3% and a SP of 97.0%. The association of CA125 with each of other antigens did not improve the SE of CA125 assay alone in the detection of patients with ovarian carcinoma. In conclusion, the present data showed that the measurement of CA15.3, MCA and CAM26 did not give any additional information with respect to CA125 assay in the diagnosis of ovarian carcinoma. The good SE and the very good SP and diagnostic accuracy of CAM29 could suggest further investigation in order to evaluate the role of this antigen in the management of patients with this malignancy.

Adenocarcinoma↗
PubMed1989

Kinetics of phototransduction in retinal rods of the newt Triturus cristatus.

1. The kinetics of photoresponses to flashes and steps of light of rods, from the retina of the newt Triturus cristatus, were analysed by recording the membrane current with a suction electrode. 2. In dark-adapted conditions the relation between the normalized amplitude of the photoresponse at a fixed time 1 s after the onset of light and the light intensity could be fitted by an exponential or a polynomial relation. In the presence of a steady bright light the same relation could be fitted by a Michaelis-Menten relation. 3. The kinetics of photoresponses to light stimuli was reconstructed using a model in which: (i) three molecules of guanosine 3'.5'-cyclic monophosphate (cyclic GMP) open a light-sensitive channel; (ii) light activates the enzyme phosphodiesterase, which hydrolyses cyclic GMP, thus closing light-sensitive channels: (iii) Ca2+ ions permeate through light-sensitive channels: and (iv) intracellular Ca2+ inhibits, in a co-operative way, the enzyme cyclase, which synthesizes cyclic GMP. 4. The model reproduces the shortening of the time to peak of brief flash photoresponses from about 1080 ms to about 690 ms with brighter lights. The model also explains the shortening of the time to peak to 350 ms observed in the presence of a steady light and the lack of a further acceleration with brighter flashes of lights. 5. The presence in the model of an intracellular calcium buffer accounts for the partial reactivation of the photocurrent following a step of light, lasting several seconds. The time course of this reactivation is not accelerated by a steady bright light both experimentally and in the model. 6. After the extinction to a long step of light the photocurrent showed a rapid partial reactivation, which was followed by a slow component of the photoresponse which extinguished with a rate constant of about 0.05 s-1. The model explains the origin of this slow component by assuming that the inactivation of excited rhodopsin is partially reversible. 7. The model is also able to explain the particular changes of kinetics when different amounts of exogenous calcium buffers are incorporated into rods (Torre, Matthews & Lamb, 1986).

Animals↗
PubMed1989

[Activity of topical flunoxaprofen in nonspecific vaginitis. Comparison with meclocycline sulfosalicylate].

A trial was performed in 30 patients affected by non-specific vaginitis. The results show that the topical application (by vaginal washings) of flunoxaprofen produces a high therapeutic activity like that of meclocycline. Contrary to meclocycline, flunoxaprofen does not possess bactericidal and bacteriostatic properties. Therefore, the normalization of vaginal flora, with a remarkable increase of Döderlein bacillus, is exclusively due to local antiphlogistic activity of flunoxaprofen. Contrary to meclocycline, flunoxaprofen induces a precocious increase of Döderlein bacillus, necessary for a definitive normalization and to limit the possibility of relapses.

Administration, Intravaginal↗
PubMed1989

The therapy of verrucous carcinoma of the vulva. Observations on three cases.

Vulvar verrucous carcinoma is a distinct variant of squamous cell carcinoma, with a very low biological aggressiveness. Surgery is considered to be the elective treatment, even if there is no agreement in literature about the extent of surgical resection. Radiotherapy cannot be used in the management of this neoplasia. Sometimes this therapeutic modality induces an anaplastic transformation of the tumor, which can turn into a more aggressive malignancy. In this paper the clinical histories of 3 patients with vulvar verrucous carcinoma are discussed, in particular as regards therapy.

Aged↗
PubMed1988

The blocking effect of l-cis-diltiazem on the light-sensitive current of isolated rods of the tiger salamander.

The effect of the organic compound l-cis-diltiazem on the light-sensitive current of isolated rods of the tiger salamander was analysed by rapidly changing the extracellular medium using the method of Hodgkin et al. (1985). Addition to the extracellular medium of small amounts of l-cis-diltiazem rapidly inhibits the photocurrent. Complete suppression of the current was observed with 1 mM l-cis-diltiazem. Half blockage of the photocurrent occurred with about 150 microM l-cis-diltiazem. The blocking effect of l-cis-diltiazem was enhanced by light and by a reduction of extracellular Na. A concentration of l-cis-diltiazem of 140 microM, which suppresses one third of the photocurrent, was able to completely suppress the photocurrent carried by Ba. It is suggested that l-cis-diltiazem blocks the light-sensitive channel, possibly competing with cyclic guanosine-3'-5'-monophosphate (cGMP) for an internal regulatory site.

Ambystoma↗
PubMed1988

The ionic selectivity of the light-sensitive current in isolated rods of the tiger salamander.

1. Using the method of Hodgkin, McNaughton & Nunn (1985) for rapidly changing the extracellular medium, we analysed the effect of divalent cations on the photocurrent of isolated retinal rods of the tiger salamander. 2. When the extracellular NaCl was replaced by equiosmolar amounts of BaCl2, SrCl2, CaCl2, MgCl2 and MnCl2 the efficacy in carrying the photocurrent at early times was Ba2+ greater than Sr2+ greater than Ca2+ greater than Mg2+ greater than Mn2+. At early times Ba2+ could carry a photocurrent similar to or larger than that carried by Na+. 3. The photocurrent carried by Ba2+ increased by about 50% when [Ca2+]o was reduced from 1 to 0.1 mM. In the presence of 0.1 mM-Ca2+ in the extracellular medium the photocurrent carried by Ba2+ saturated when [Ba2+]o was close to 50 mM and was half-activated at 15 mM [Ba2+]o. 4. The photocurrent which can be carried by Sr2+ is not larger than that carried by Ba2+ and does not saturate for [Sr2+]o up to 70 mM. 5. When extracellular Na+ is replaced by the impermeant organic ion choline it is possible to observe a transient photocurrent which is carried by Ca2+. This current has a maximal value of about 11 pA and has a half-activation constant of about 50 microM. 6. Movements of Mg2+ across the light-sensitive channel can be seen only when extracellular Ca2+ is reduced below 10 microM. Under these conditions the maximal photocurrent which can be carried by Mg2+ at early times is about 8 pA and has a half-activation of about 2 mM. Under normal conditions Mn2+ is hardly permeable through the light-sensitive channel. 7. It is concluded that the selectivity of the light-sensitive channel in the low ionic concentration range is Ca2+ greater than Sr2+ greater than Ba2+ greater than Mg2+ greater than Na+.

Action Potentials↗
PubMed1988

The modulation of the ionic selectivity of the light-sensitive current in isolated rods of the tiger salamander.

1. By using the method of Hodgkin, McNaughton & Nunn (1985) for rapidly changing the extracellular medium, we analysed the effect of the organic compound IBMX (3-isobutyl-1-methylxanthine) on the movement of divalent cations through the light-sensitive channels of isolated retinal rods of the tiger salamander. 2. When the rod is treated with 0.5 mM-IBMX it is possible to observe photocurrents larger than 50 pA carried by Ba2+, Sr2+, Ca2+, Mg2+ and Mn2+. Under these conditions Ca2+, Mg2+ and Mn2+ carry photocurrents of similar amplitude, while Ba2+ and Sr2+ usually carry larger photocurrents. 3. The movement of Mn2+ through the light-sensitive channel, which is hardly detected under normal conditions, can also be observed after treating the rod for a few seconds with a solution containing 35 mM[Na+]o and 10(-7) M[Ca2+]o. Under these conditions the photocurrent carried by Mn2+ is fully saturated in the presence of 1 mM-extracellular Mn2+. 4. When the rod is pre-treated with an extracellular solution containing 0.5 mM-IBMX the maximal photocurrent which can be carried by 10 mM [Ca2+]o increases from about 10 pA to approximately 200 pA. In these conditions the half-activation of the Ca2+ current is between 1 and 10 mM, that is 20-50 times higher than in normal conditions (Menini, Rispoli & Torre, 1988). 5. When the rod is pre-treated with an extracellular solution containing 0.5 mM-IBMX the half-activation of the photocurrent which can be carried by Mg2+, Ba2+ and Sr2+ is equivalent to or greater than 10 mM. In the absence of pre-treatment with IBMX the half-activation of the photocurrent carried by Mg2+, Ba2+ and Sr2+ is less than 5 mM. 6. We conclude that the light-sensitive channel can exist in at least two distinct open states. The selectivity of the channel in the first open state is as described in a previous paper (Menini et al. 1988). Mn2+, which is hardly permeable through the light-sensitive channel in the first open state, can move through the light-sensitive channel in the second open state. Ca2+, Mg2+, Ba2+ and Sr2+ permeate more freely through the light-sensitive channel in the second open state, probably because the electrostatic interactions between these ions and the channel are less strong.

1-Methyl-3-isobutylxanthine↗
PubMed1988

The effect of cadmium on the light-sensitive current of isolated rods of the tiger salamander.

The effect of cadmium on the light-sensitive current of isolated rods of the tiger salamander was analysed by rapidly changing the ionic medium using the technique of Hodgkin et al. (1985). Addition of millimolar amounts of cadmium to the extracellular medium caused a rapid, but transient, decrease of the photocurrent. The effect of cadmium on the movement of divalent cations, such as Ba2+ and Ca2+, differs according to the experimental protocol: when cadmium is introduced into the bathing medium at the same time as Ca2+ or Ba2+, it blocks the entry of these ions into the rod; and when the rod is exposed to cadmium first for a few seconds the entry of Ca2+ and Ba2+ is enhanced. The effect of cadmium is best explained as a dual effect: firstly, an external effect on the channel, and secondly, by metabolic changes, which are caused by a drop of intracellular Ca2+.

Ambystoma↗
PubMed1985

Mechanisms of light adaptation in toad rods.

A steady illumination equivalent to about 1000 or more photoisomerizations per s per rod completely abolishes the dark current and induces a total desensitization of toad rods. Under these conditions, however, both current and sensitivity recover from the initial suppression and reach a new steady level within about 30 s. Both extent and time course of recovery depend on the intensity of the conditioning light. The ability of rods to respond to light stimuli under light saturating conditions is enhanced by procedures aimed at increasing the sodium gradient across their surface membrane. The results suggest that rods can also contribute significantly to vision at photopic levels of ambient light. The mechanisms underlying this adaptational property of rods are discussed.

Acclimatization↗
PubMed1978

[Wounds of the heart. Diagnostic study and clinical case reports].

Two cases of cardiac wounds in association with acute anaemia and acute cardiac tamponade respectively are presented. The statistical and, more particularly, the diagnostic factors involved are discussed. Stress is laid on the measurement of CVP along with pericardiocentesis. Correct interpretation of the data furnished by these two methods will lead to exact and immediate diagnosis in all cases, and so enable the correct therapeutic strategy to be chosen.

Adult↗