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Biomedical subjects

G Conte

Publications and source records attributed to G Conte.

At least 91 records · Page 5Linked to original sources
PubMed1991

Acute effects of ciclosporin on renal hemodynamics and urinary protein excretion in patients with the nephrotic syndrome.

The possibility that the renal hemodynamic abnormalities associated with ciclosporin (CS) administration are enhanced in nephrotic patients (NP), leading to severe impairment of renal function and/or to modifications in proteinuria, has not hitherto been tested. Ten NP and 8 healthy subjects (NC) were examined before and after oral CS administration (10 mg/kg body weight in NP and 12 mg/kg body weight in NC: a lower dosage was adopted in NP because of edema overestimating the actual body weight) under water diuresis by standard renal clearance methods. Basal blood volume was lower in NP. Blood CS levels were not significantly different in the two groups. Basal glomerular filtration rate (GFR) was similar in NP and NC, while renal plasma flow (RPF) was lower in NP. After CS, both GFR and RPF significantly decreased in the two groups, but the percent decrease in inulin clearance was greater in NP. Filtration fraction increased only in NC. Basal renal vascular resistances were greater in NP, and significantly increased after CS in both groups. Basal fractional sodium excretion (FENa) was lower in NP: after CS FENa decreased only in NC. Neither plasma renin activity, nor plasma aldosterone changed after CS. When urinary protein excretion (UP) was corrected by GFR, no change was observed after CS; by contrast, selectivity of proteinuria (as assessed by the CIgG/CTransferrin ratio) markedly increased. Our data indicate that CS induces a greater fall in the GFR in hypovolemic NP than in healthy subjects, probably because in the former GFR becomes extremely plasma flow dependent.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

[The prognostic factors for the radiation treatment of the cerebral metastases from breast carcinoma].

Complex mechanisms of various nature, not only physical, can influence the patterns of metastases. We compared the patients with recurrences to the brain as the only metastatic site from breast cancer with the patients relapsing in the brain and other organs. All cases were staged and treated following professional protocols. When brain metastases were diagnosed, the patients were accurately restaged before being submitted to radiation therapy; the whole brain was irradiated with various total doses and the same fractionation. The patients underwent clinical examination before and after irradiation. Survival analysis was carried out using the product-limit method considering the following periods: total survival, relapse-free survival, elapsed time till the appearance of brain metastases, and survival after radiation therapy. The cases were grouped and compared using Mantel-Cox and Breslow methods according to the following prognostic factors: brain as the first site of recurrence, pausal state, total radiation dose, stage (TNM), T and N. No significant difference in survival was observed between the cases with brain as the first metastasized organ and the others. The patients were grouped according to the extant prognostic factors: longer total and postirradiation survival rates were observed in patients in premenopausal state (Breslow: p = 0.025 and 0.005) and in the cases treated with total radiation doses greater than 40 Gy (Breslow: p = 0.023 and 0.005). T levels seemed to significantly affect all the examined periods--which influences the stage effect. Conversely, N levels seemed to be of no significant value. The menopausal factor may reflect the effects of age, from which it cannot be separated. These results can be useful for treatment planning.

Brain Neoplasms↗
PubMed1991

Calcium antagonists and hormone release. VII. Effects of gallopamil infusion on insulin and C peptide release in normal subjects.

It is known that insulin release is calcium-dependent and that calcium-antagonists, blocking calcium transport across cell membranes, inhibit it, especially interfering with the second phase of insulin secretion. Gallopamil (GAL) is a new calcium-antagonist that, although structurally similar to verapamil, has more potency. It blocks slow calcium channels and fast sodium channels. Even if it has been demonstrated in vitro, there is no evidence that GAL is able to impair the glucose-induced insulin release in humans. We have submitted five normal subjects (24-36 yr old) to oral glucose tolerance test (OGTT, 75 g of glucose p.o.) and OGTT plus GAL infusion test (1 mg i.v. as a bolus, followed by a 2 mg/hr infusion for 2.5 hr, starting 30 min before glucose load), in two different days, to determine the effects of GAL on insulin and C peptide release after oral glucose load. In opposite with verapamil effects, we found that GAL did not reduce the peak levels of insulin and C peptide, but the peak response was delayed and the incremental areas tended to increase during GAL infusion, so that an impairment of glucose tolerance was equally obtained. This study indicates that different calcium-antagonist drugs exert differential effects on insulin release and their action on glucose homeostasis should be kept in mind because of the large use of these drugs in cardiac patients.

Adult↗
PubMed1990

Acute increase in plasma osmolality as a cause of hyperkalemia in patients with renal failure.

These studies were performed in patients with chronic renal failure to understand the mechanism(s) of hyperkalemia secondary to hypertonic NaCl infusion. In 10 patients, after intravenous infusion of either 5% or 2.5% NaCl (6 mEq per kg body wt for 120 minutes in both solutions), the maximum increase in plasma potassium averaged 0.6 (range 0.3 to 1.3) mmol/liter (P less than 0.01) or 0.3 (range 0.2 to 0.6) mmol/liter (P less than 0.01), respectively. The rise of both plasma potassium and osmolality was significantly higher during 5% NaCl than during 2.5% NaCl infusion (P less than 0.01). A significant linear correlation (P less than 0.01) between plasma potassium and osmolality was observed. Urinary potassium excretion was increased to a similar extent by 5% NaCl and 2.5% NaCl infusion. The observed hyperkalemia, secondary to NaCl infusion, was independent of venous pH, plasma bicarbonate, anion gap, insulin levels, and urinary norepinephrine and epinephrine excretion, and was associated with a fall in plasma aldosterone concentration. In separate studies, nine patients were treated with desoxycorticosterone acetate (DOCA; 20 mg i.m. for three days) before receiving saline (5%) infusion. DOCA did not prevent the level increase in plasma potassium that remained significantly correlated with plasma osmolality (P less than 0.01). In conclusion, hypertonic NaCl infusion in patients with renal failure causes a clinically relevant hyperkalemia despite increased renal excretion of potassium. This hyperkalemia is independent of acid-base or hormonal mechanisms known to regulate extrarenal homeostasis of potassium, and is strictly correlated with a rise in plasma osmolality.

Acid-Base Equilibrium↗
PubMed1990

Absence of acute nephrotoxicity with low doses of cyclosporin: experimental study in the rat.

No study has, to our knowledge, evaluated the acute effects of low immunosuppressive doses of cyclosporin (CsA) on renal function. To establish whether a relationship exists between the dosage of CsA and the onset of nephrotoxicity, 28 rats were studied by renal clearances before (control) and after i.v. administration of different doses of CsA: 3 mg/kg b.w. (group 1); 7 mg/kg b.w. (group 2); 11 mg/kg b.w. (group 3); 15 mg/kg b.w. (group 4). No change in renal function was observed between control and the post-CsA period in groups 1 and 2. GFR (inulin clearance) was decreased vs the control period in group 3 and group 4 (-22% and -37%, respectively, P less than 0.001); the difference between these two groups was statistically significant (P less than 0.01). Effective renal plasma flow (PAH clearance) was similarly decreased in groups 3 and 4 vs their control periods (-21% and -28%, respectively, P less than 0.001) due to the increase of total renal vascular resistance (+41% and +42%, respectively, P less than 0.001). Filtration fraction was significantly decreased by CsA in group 4 (P less than 0.01 vs the control period). PAH renal extraction, urinary volume, and sodium and potassium excretion were similar in all groups before and after CsA. PRA and ADH were significantly increased only in group 4 (P less than 0.01) vs the baseline values. A high and significant relationship was detected between CsA dosage and the decrease of GFR (r = 0.81, P less than 0.001) and RPF (r = 0.612, P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1990

Celibacy and fertility rates in patients with major affective disorders: the relevance of delusional symptoms and suicidal behaviour.

The celibacy and fertility rates of 186 patients with major affective disorders were analysed as a function of the presence or absence of histories of mood congruent delusions or suicidal behaviour in the depressive phases of the disease. Both delusional and suicidal histories were irrelevant to celibacy rates. On the contrary, delusional depressives had a reduced incidence of cases with 2 or more children and suicide attempters had both a lower frequency of high-fertility cases and a smaller mean number of children than nonattempters. The differences were apparently not attributable to the length of the fertile period of life spent in illness.

Adult↗
PubMed1990

Role of atrial natriuretic factor in renal adaptation to variation of salt intake in humans.

This study was performed to define the extent to which atrial natriuretic factor (ANF) contributes to upregulate salt excretion in subjects eating a high-salt diet. Eight normal volunteers were first studied at low-salt diet (80 mmol NaCl/day); urinary sodium excretion (UNaV) and plasma ANF (PANF) were measured in the basal condition and during stepwise infusion of human alpha-ANF at 2, 4, 8, and 16 ng.min-1.kg-1. Then the same subjects were shifted to a high-salt diet (400 mmol/day), and UNaV and PANF were measured in the new balance condition. At low-salt diet, UNaV averaged 0.069 meq/min, and PANF averaged 21 pg/ml; infusion of human alpha-ANF raised stepwise both UNaV and PANF (means in meq/min and pg/ml, respectively, were 0.177 and 46, 0.218 and 76, 0.360 and 86, and 0.601 and 182). Infusion of ANF caused a progressive fall of plasma aldosterone and plasma renin activity. Mean UNaV and PANF at high-salt diet were 0.301 meq/min and 35 pg/ml. Thus, by increasing experimentally PANF in a low-salt diet condition to the levels occurring physiologically in a high-salt diet condition, a significant rise in UNaV is evoked, which accounts for approximately 50% of the rise of UNaV that is necessary to balance the increased salt intake.

Adaptation, Physiological↗
PubMed1990

[Platelet labelling with In-111-oxine: platelet survival and the images].

We studied 10 male and 2 female normal non-smoker volunteers (mean age 25) by labeling of autologous platelets with 111-In oxine. Daily samples for platelet survival were obtained in all, gamma-camera images in 10 and blood pool digital subtraction with 99m-Tc labeled erythrocytes in 6. Mean platelet count was 594 +/- 235 10(3)/mm3; collagen platelet aggregation pre and post labeling was 74 +/- 4.8 and 70 +/- 10%, respectively. Mean labeling efficacy was 65 +/- 15.4%, mean labeling dose was 201 +/- 79.5 microCi. A linearized initial survival of 7.9 +/- 1 day was obtained. Scintigraphic images showed circulating activity, greater in the spleen, persisting after digital subtraction. The method described can be used for clinical evaluation of platelet disorders and thrombosis.

Adult↗
PubMed1990

[Photon or electron irradiation of the internal breast lymph node chain. Experimental dosimetry and clinical implications].

The radiation therapy of internal mammary chain, according to many other authors, is indicated in patients with N + breast cancer or with inner quadrant disease. Since the direct field with gamma radiation seems to induce important adverse effects on myocardium, the authors were induced to check experimentally dose distributions of 12-15 MeV electron beams and compare the results to gamma photon dose distribution. Materials and dosimetric methods as well as experimental results are described. Moreover theoretic and practical point of view are discussed coming to the conclusion that electron beams are more suitable for myocardial saving. Nevertheless some technical variations are required, to maintain the typical homogeneity of photon beams.

Breast Neoplasms↗
PubMed1990

[Changes in lymphocyte subsets after radiotherapy].

Radiation therapy seems to induce depletion of lymphocytes, which are very important cells for immunity response. The lymphocyte phenotype was studied in 41 non-pretreated patients with normal immunological parameters who received postoperative radiation therapy for breast, mediastinal or pelvic cancer with at least 50 Gy/25 fractions. The functional immunological assessment was analyzed by Multiskin test (Merieux) too. The lymphocyte phenotype was determined on whole-blood lysate employing an Ortho double-fluorescence cytofluorimeter. All patients, after radiation treatment, exhibited decrement in absolute and percent lymphocyte subpopulations; the Multiskin test demonstrated simultaneous change in skin-test response. The results are highly significant (p 2-tailed area less than 0.0001) for absolute cells count and skin-delayed response test, but percent variations are not significant when verified by t-test.

Humans↗
PubMed1989

Re-evaluation of the linkage relationship between chromosome 11p loci and the gene for bipolar affective disorder in the Old Order Amish.

Reanalysis of an Old Order Amish pedigree, to include several new individuals and two changes in clinical status, markedly reduces the probability of linkage between bipolar affective disorder and the Harvey-ras-1 oncogene and insulin loci on chromosome 11. This linkage can be excluded using a large lateral extension of the original Amish pedigree.

Bipolar Disorder↗
PubMed1989

Acute cyclosporine renal dysfunction reversed by dopamine infusion in healthy subjects.

Up to now, no studies have been performed in normal humans to investigate the role of renal hemodynamic abnormalities in relation to acute-cyclosporin A (CsA) renal dysfunction and to verify whether the specific renal vasodilator, dopamine, can counteract these abnormalities. Eight normal subjects were examined both (A) after oral CsA (12 mg/kg body wt) and (B) after oral CsA + dopamine infusion (2 mg/kg body wt/min), under water diuresis. Both in protocols A and in B, four basal renal clearances were performed before CsA and every twenty minutes for four hours after CsA administration. In protocol A, after CsA, inulin (GFR) and PAH clearance (RPF) fell by up to 27% and to 41%, respectively, so that filtration fraction (FF) increased (P less than 0.01). A slight (not significant) hypertension occurred while renal resistances were markedly raised (P less than 0.001). Fractional urine and Na+ excretion as well as CH2O decreased, while UOsm increased (P less than 0.01). In protocol B, dopamine was infused from 120 to 180 minutes after CsA (that is, when the maximal adverse effects of CsA on renal hemodynamics had been observed in A). Dopamine infusion could reverse completely the effects of CsA on RPF, GFR, fractional urine output and CH2O; only UOsm remained higher than normal in conclusion with an increased fractional excretion of sodium (P less than 0.01). No changes were observed in plasma renin activity, aldosterone and in urinary epinephrine and norepinephrine excretion both in protocols.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Neurotic traits and disease duration in headache patients.

The purpose of this study was to test the hypothesis that duration of illness is correlated with neurotic personality traits. Four hundred and eighteen patients with migraine, tension, and mixed headaches were studied. The MMPI was used to evaluate the patients' personality characteristics. Scales employed were: scale 1--hypochondriasis, scale 2--depression, scale 3--hysteria, and scale 7--psychasthenia. The MMPI scale scores were analysed with regard to sex, diagnosis, and duration of illness. Patients with mixed headaches showed significantly more elevated scores on the MMPI scales than those suffering from migraine and tension headaches. No correlation was found between any of the MMPI scale scores and the duration of illness. No interaction was found between duration of illness and the diagnostic categories of headache in determining the MMPI neurotic scale scores. It is hypothesized that the higher MMPI scores found in patients with mixed headache is characteristic of these patients.

Adolescent↗
PubMed1989

Reversibility of acute cyclosporin nephrotoxicity by dopamine. Micropuncture study in the rat.

The ability of dopamine to neutralise the effects acutely induced by cyclosporin (CsA) on glomerular dynamics was evaluated in four groups of female Munich-Wistar rats, prepared for micropuncture: group I (n = 9), normal rats receiving saline as placebo; group II (n = 10), rats treated with CsA (20 mg/kg b.w. in 1 h); group III (n = 8) rats treated with CsA, as in group II, and then with vasodilating doses of dopamine (1.2-2.0 micrograms/100 g b.w./min in continuous intravenous infusion); group IV (n = 7), rats administered Cremophore EL, the vehicle of CsA, in corresponding doses. Single nephron GFR (SNGFR), glomerular plasma flow (GPF), afferent and efferent arteriole resistances (Ra and Re, respectively), SN filtration fraction (SNFF), ultrafiltration coefficient (Kf) were measured. Body weight, blood pressure and haematocrit were similar in the four groups. GFR was significantly reduced in group II (0.83 +/- 0.08 ml/min vs 1.29 +/- 0.01 in group I, 1.46 +/- 0.25 in group III, and 1.40 +/- 0.09 in group IV, P less than 0.05 vs all the groups), while no statistical difference was detected in urinary volume. SNGFR was significantly reduced in group II vs group I (18.7 +/- 1.8 nl/min vs 30.6 +/- 1.3, P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Renal function in chronic lithium-treated patients.

We investigated the renal function (urine volume, glomerular filtration rate, urinary osmolality and proteinuria) of 50 patients chronically treated with lithium carbonate for major affective disorder. No patient had any alteration in the parameters considered. No relationship was found between any of the parameters studied and duration of illness or lithium levels, both in serum and red blood cells. These results were confirmed by the administration of the DDAVP test to 10 patients of the original sample; no alteration of concentration ability was found. We suggest that the discrepancy between our findings and those of most authors was a result of the serum lithium level of our patient sample, which was lower than that usually used in other studies.

Adult↗