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Biomedical subjects

D Alberti

Publications and source records attributed to D Alberti.

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

A phase I study of SR-2508 and cyclophosphamide administered by intravenous injection.

SR-2508, a less lipophilic ane neurotoxic analogue of the nitroimidazole, misonidazole, has exhibited significant chemosensitization properties in preclinical studies with alkylating agents. A phase I trial was carried out to assess toxicity and possible pharmacological interactions of the combination of short infusions of SR-2508 and cyclophosphamide (CP). Patients were randomly assigned to receive either CP alone followed in 3 wk by CP + SR-2508, or CP + SR-2508 followed by CP alone. All additional courses were CP + SR-2508. The maximum tolerated dose of the combination was determined by dose escalation of SR-2508 while the dose of CP remained fixed, initially 1.0 g/m2, and then a second maximum tolerated dose was determined with CP at 1.6 g/m2. One hundred seventeen evaluated courses were administered to 39 patients, the majority of whom had received prior treatment. Somewhat unexpectedly, reversible grade 4 granulocytopenia was the dose-limiting toxicity occurring in four of five evaluable first combination courses at level 6 (SR-2508, 11.3 g/m2; CP, 1.0 g/m2), the initial maximum tolerated dose. SR-2508 enhanced CP-induced myelosuppression as exhibited by the significant difference (p less than 0.001) between the 27 paired courses (CP versus CP + SR-2508) for WBC nadirs over levels 1 to 6. The neurotoxicity encountered was similar to that seen in past clinical trials, being reversible, mild, and usually peripheral in nature. There was one treatment-related death (neutropenic sepsis) on study. No other significant toxicity was seen. SR-2508 exhibited linear pharmacokinetics over the dose range studied. The SR-2508 area under the concentration-time curve increased linearly with dose (r = 0.858; p less than 0.001). No other parameters were dose related. Neither drug appeared to affect the pharmacokinetics of the other, and CP pharmacokinetic values were consistent with those from prior studies. Due to the interaction noted between the two agents and the preclinical data suggesting preferential enhancement of antitumor efficacy under this combination, phase II study appears warranted.

Adult↗
PubMed1991

Cadralazine versus prazosin as second-step treatment in hypertensive patients on beta-blockers: a randomized multicentre study. The Italian Multicentre Study Group.

A randomized multicentre between-patient study comparison has been made of the efficacy and tolerability of cadralazine and prazosin, both administered for 6 weeks to hypertensive patients with a supine diastolic blood pressure (DBP) greater than or equal to 95 mmHg whilst on a beta-adrenoceptor-blocker. The doses of the beta-adrenoceptor-blocker (metoprolol SR 200 mg once daily) and cadralazine (10 mg once daily) were held constant during the study, while prazosin was individually titrated from 0.5 mg to a maximum of 2 mg tds. 108 patients (50 m and 58 f; mean age 54 y) were enrolled in 12 centres. Twelve patients withdrew due to adverse effects or poor efficacy (5 patients on prazosin and 7 on cadralazine). Both treatments induced a similar significant reduction in systolic blood pressure (SBP) and DBP, allowing normalization of BP in 58% of subjects on cadralazine and 55% on prazosin. Heart Rate (hR) increased significantly from 67 to 72 beats.min-1 in those on cadralazine and from 65 to 69 beats.min-1 on prazosin. Body weight was unchanged. Adverse effects were mild and typical of vasodilators, such as headache, flushing and dizziness. Physician evaluation of drug efficacy was not different between drugs, and cadralazine was rated better in terms of tolerability. Thus, in this multicentre study, cadralazine in the fixed dose of 10 mg once daily, as a second-step antihypertensive treatment in patients not satisfactorily controlled by a beta-adrenoceptor-blocker, was as effective and showed a similar side effect profile to prazosin given three times daily.

Adrenergic beta-Antagonists↗
PubMed1991

Effects of pyridostigmine on spontaneous and growth hormone-releasing hormone stimulated growth hormone secretion in children on daily glucocorticoid therapy after liver transplantation.

OBJECTIVES: We aimed to investigate both nocturnal spontaneous and morning growth hormone (GH)-releasing hormone (GHRH)-induced GH secretion in children on daily glucocorticoid treatment after liver transplantation and to evaluate the effect of pyridostigmine (an acetylcholinesterase inhibitor thought to reduce hypothalamic somatostatin tone) on GH secretion in these patients. DESIGN: We performed a randomized, single-blind, cross-over study. PATIENTS: We studied three male and three female juvenile patients, within a year of orthotopic liver transplantation and under immunosuppressive glucocorticoid therapy (mean dose +/- SEM, 5.92 +/- 0.63 mg/day) and five normal children (four males, one female). MEASUREMENTS: Both nocturnal spontaneous and morning GHRH-induced GH secretion were evaluated after administration of placebo, 1 tablet p.o., or pyridostigmine, 2 mg/kg p.o. RESULTS: Spontaneous GH. Placebo: in liver transplanted children nocturnal GH secretion (mean GH level 10.8 +/- 2.0 mU/l) was not significantly different with respect to normal children (mean GH level 12.8 +/- 1.2 mU/l); pyridostigmine: nocturnal GH secretion was significantly increased as compared to placebo in subjects with liver transplantation but not in normal children. GHRH test. Placebo: liver transplanted patients showed a blunted GH response to GHRH with respect to normal children; pyridostigmine: the GH responses to GHRH (P less than 0.05) increased as compared to placebo and did not differ significantly in the two groups. CONCLUSIONS: Our data suggest a steroid-mediated increase in hypothalamic somatostatin tone in liver transplanted children.

Child↗
PubMed1991

[Effects of benazepril, a new ACE inhibitor, in effort angina pectoris].

The aim of this study was to evaluate the anti-ischemic efficacy of 2 different doses of benazepril (B), a new ACE-inhibitor, 10 and 20 mg, given per os. Fifteen male patients gave informed, written consent; they were aged 40-67 years, with stable effort angina pectoris and were randomly given, in double-blind condition, a tablet containing B 10 mg, B 20 mg or placebo (PL), once a day, according to a 3 x 3 latin square design. Bicycle exercise tests were performed on the same day, 2 and 10 hours after the last drug intake. B 10 mg and B 20 mg, in patients with stable effort angina, compared to placebo, increased ischemic threshold and decreased ischemic ST depression at maximal work, after 2 hours but not after 10 hours. In conclusion B 10 mg and B 20 mg showed anti-ischemic activity 2 hours after drug intake.

Adult↗
PubMed1991

[Transdermal nitroglycerin in stable effort angina. I. Therapeutic effect and duration of the action of a single dose. Comparison with placebo and isosorbide dinitrate].

To assess the efficacy of 2 doses of a transdermal system for nitroglycerin, 10 and 20 mg (NTTS 10 and NTTS 20) and isosorbide dinitrate 40 mg (ISD 40) on exercise tolerance test, a double-blind within patients placebo (PL) controlled study was performed: 12 male patients, aged 47-71 years, with stable effort angina, with fixed ischemic threshold, received, according to a 4 x 4 latin square design, NTTS 10, NTTS 20, ISD 40 and PL, at 7.00 am on 4 consecutive days. Bicycle exercise tests were performed 4 and 12 hours post-dosing, after which the systems were removed. NTTS 10 and 20 and ISD 40 increased significantly ischemic threshold, anginal threshold and decreased maximal ST depression at the fourth hour. Only NTTS 10 and NTTS 20 showed antiischemic activity after 12 hours. During exercise, at the fourth and twelfth hour, there was no significant difference in rate-pressure product between placebo and NTTS 10 and 20 and ISD 40. Therefore the antiischemic activity of these drugs was not related to a decrease of myocardial oxygen consumption. In conclusion, in comparison with PL, NTTS 10, 20 and ISD 40 had antiischemic and antianginal activity at the fourth hour, while at the twelfth hour this activity was observed only after NTTS 10 and 20, without differences between the 2 doses.

Administration, Cutaneous↗
PubMed1991

[Transdermal nitroglycerin in stable effort angina. II. Administration of continuous high doses and alternate high-low doses. Absence of tolerance].

Aim of this study was to evaluate the efficacy of 2 different schedules of nitroglycerin (N), given by means of transdermal therapeutic system (TTS): continuous (20 mg patch at 8.00 am and at 8.00 pm NTTS/c) and high/low doses therapy (20 mg patch at 8.00 am and 10 mg at 8.00 pm NTTS/a), respectively. Eighteen volunteers, gave informed, written consent; male patients, aged 57 +/- 2 years, with stable effort angina pectoris, were randomly given, in double-blind condition, NTTS/c, NTTS/a or placebo (PL), each for 1 week period, according to a 3 x 3 latin square design. Bicycle exercise tests were performed on the first and on the last day of each period of the study, 12 hours after the last patch. NTTS/c and NTTS/a increased ischemic threshold and decreased the ischemic depression ST at maximal common work, compared to placebo, without differences between tests performed at 1 and 7 day. In conclusion, NTTS/a showed antiischemic activity after 7 days, so no tolerance was observed in those patients.

Administration, Cutaneous↗
PubMed1990

Liver transplantation in children less than 1 year of age.

Of 139 children who received an orthotopic liver transplant in our center between March 1984 and July 1989, a total of 17 patients (12%) had transplants before their first birthday (mean age 10.3 months; range 8 to 11). The mean weight was 7.3 kg (range 5.2 to 13). Nine retransplantations were performed in five children because of primary nonfunction (three children), hepatic artery thrombosis (four), or rejection (two). A reduced donor liver was used for 11 of 26 transplants. Baseline immunosuppression included cyclosporine, prednisone, and azathioprine with OKT3 or anti-thymocyte globulin for steroid-resistant rejection episodes. Survivors were discharged after a mean hospital stay of 47 days (range 22 to 87), and nonsurvivors died within a mean of 40 days (range 0 to 120). The 1 year actuarial survival rate was 64.7%, in comparison with 75.8% in the whole series. One patient died perioperatively, two died from primary nonfunction, one from adenovirus infection, two from rejection, and one from bone marrow aplasia. Eighteen rejection episodes, of which 11 were steroid resistant, occurred in 11 patients. Our series shows that liver transplantation can be successful in this age group.

Biliary Atresia↗
PubMed1990

Effects of ACE inhibition in normotensive patients with chronic glomerular disease and normal renal function.

A double-blind, placebo-controlled study was carried out to assess the effects of a three-month treatment with a new ACE inhibitor, Benazepril (BNZ), on systemic and renal hemodynamics, and urine protein excretion, in 20 patients with chronic glomerulonephritis, normal blood pressure (130/83 +/- 16/10 mm Hg), and normal renal function (creatine clearance 106 +/- 25 ml/min). Treatments with placebo or BNZ were assigned randomly. A wide range of proteinuria lowering effect was observed in overall population (from 1 to 84%, average 34%). Following the arbitrary level of a 30% reduction, two well-matched subgroups (10 patients for each one) were obtained: "good responders" (average decrease 51%), and "poor responders" (average decrease 17%). The main distinctive feature between the two groups was a higher plasma renin activity level in good than in poor responders. A positive correlation between the fall in proteinuria and blood pressure was found. Although the decrease in blood pressure seems to represent the major factor in determining the reduction in proteinuria, a multiple correlation analysis showed that the most prominent role (71%) was attributable to the combined decrease in blood pressure and filtration fraction, and then also to the efferent arteriole dilatation. Our conclusion is that ACE inhibitors are capable of also reducing proteinuria in patients with renal disease with normal blood pressure, the effect being more pronounced in those exhibiting humoral, systemic and renal hemodynamic patterns, indicating a greater activity of circulating and renal renin angiotensin system.

Adult↗
PubMed1990

Renal functional reserve in patients with essential hypertension: effect of inhibition of the renin--angiotensin system.

1. Urinary albumin excretion and the effect of an acute oral protein load (a meat meal) on glomerular filtration rate ('renal functional reserve') were evaluated in 15 essential hypertensive patients with preserved renal function and compared with 12 normal subjects. 2. Seven patients had microalbuminuria (greater than 30 mg/day) that was not correlated with blood pressure values. 3. After an oral protein load, an average increase of 20% in glomerular filtration rate (from 91 +/- 19 to 110 +/- 27 ml min-1 1.73 m-2 was found in the hypertensive patients. This change was not statistically different from that observed in normal controls (from 102 +/- 7 to 124 +/- 9 ml min-1 1.73 m-2). The glomerular response in hypertensive patients was independent of age, duration of hypertension, blood pressure, plasma renin activity, urinary albumin excretion and retinal vascular alterations. 4. All patients were re-evaluated after 6 weeks treatment with a new orally active angiotensin-converting enzyme inhibitor, benazepril. Systolic, diastolic and mean blood pressures were lowered in all the patients, but the drug did not affect the glomerular response to acute protein ingestion or the magnitude of urinary albumin excretion. 5. The findings of a normal 'renal functional reserve' and a lack of change in both urinary albumin excretion and the glomerular response after angiotensin-converting enzyme inhibition cast doubt on the existence of increased intraglomerular pressure in hypertensive patients.

Adult↗
PubMed1990

Size reduction of the donor liver is a safe way to alleviate the shortage of size-matched organs in pediatric liver transplantation.

The development of pediatric liver transplantation is considerably hampered by the dire shortage of small donor organs. This is a very sad situation because in most experienced centers, liver replacement can offer a long-term hope of survival of more than 70% in a growing variety of pediatric liver disorders. The reported experience with 54 reduced-size grafts on a total of 141 transplants performed in 117 children between 1984 and 1988 demonstrates that the technique of reduced-size liver transplantation not only allows long-term survival but, in fact, offers the same survival hope with the same quality of liver function, regardless of the child's age and clinical condition. The prominent feature of our experience with the reduced liver concerns its deliberate use for elective cases. Seventy-seven per cent of the 30 children who electively received a reduced liver were alive 1 year after transplantation, as were 85% of the 62 children who received a full-size graft. There is no difference in the long-term survival rate of patients who received elective grafts, which is in the range of 75% with both techniques.

Adolescent↗
PubMed1990

Systemic and renal effects of a new angiotensin converting enzyme inhibitor, benazepril, in essential hypertension.

Seventeen essential hypertensive patients with normal renal function were treated with a new non-sulphydryl orally active angiotensin converting enzyme (ACE) inhibitor, benazepril, 10 mg given once or twice daily, according to diastolic blood pressure levels, for 6 weeks. In all patients, changes in blood pressure, systemic and renal hemodynamics, plasma renin activity and urinary aldosterone and albumin excretions were assessed at the end of a 2-week placebo run-in period and at the end of the study. Benazepril monotherapy controlled blood pressure well. No changes in cardiac output, heart rate or stroke volume were observed, while peripheral vascular resistance was significantly decreased (-11%, P less than 0.05). Plasma volume was unaltered. The glomerular filtration rate was stable, but effective renal plasma flow was increased because of the marked reduction in renal vascular resistance (-35%) and, therefore, the filtration fraction was decreased. Urinary albumin excretion remained unchanged. A significant increase in plasma renin activity (P less than 0.001) and a decrease in urinary aldosterone excretion were seen. No side effects were observed during the treatment period. In conclusion, our results suggest that benazepril alone is an effective antihypertensive agent in patients with essential hypertension. The blood pressure lowering effect is due mainly to systemic vasodilation and is observed up to 24 h after administration of the drug. The vasodilation appears to be more consistent in the renal than in the systemic circulation.

Adult↗
PubMed1990

The concept and technique of the split liver in clinical transplantation.

Extreme scarcity of small pediatric donors makes a search necessary for technical variants to benefit infants and small children from the larger group of potential adolescent and adult donors. Three such technical variants are available for orthotopic transplantation. The reduced-size graft allows a weight ratio between donor and recipient of up to 4 to 6. The segmental graft allows transplantation of segments of livers from adult donors into infants and small children of up to a weight ratio of 8 to 9. The technique of the split liver, whereby one single donor liver is divided in such a way as to obtain two viable grafts for transplantation into two different recipients, is the most recent technical variant used to increase the flexibility of liver replacement and maximize the use of the donor liver pool. We report herein our two first cases of split liver with transplantation in four different recipients, with two long-term survivors. The described technique can also be useful in urgent adult transplantation.

Adult↗
PubMed1989

Methotrexate and dipyridamole combination chemotherapy based upon inhibition of nucleoside salvage in humans.

We have carried out a clinical trial in 23 patients to determine whether dipyridamole modulates the clinical effect of methotrexate. This trial was based upon in vitro studies which indicate that dipyridamole potentiates the cytotoxic action of methotrexate through inhibition of thymidine salvage. Methotrexate was given as a bolus injection 24 h after initiation of a high dose dipyridamole infusion. The trial was designed so that methotrexate was escalated in individuals until toxicity occurred and then the methotrexate dose resulting in toxicity was repeated without dipyridamole. During the course of this study the methotrexate dose was escalated from 10 to 130 mg/m2. While individual patient tolerance varied, moderate to severe myelosuppression and/or mucositis occurred frequently in patients receiving the combination with methotrexate doses greater than or equal to 60 mg/m2. Ten of 10 patients who experienced moderate or severe toxicity with the combination had significantly less toxicity when treated with methotrexate alone. Dipyridamole did not increase toxicity by an alteration in methotrexate elimination. The potentiation of methotrexate by dipyridamole in these patients suggests that physiological thymidine levels are sufficient to perturb the clinical effects of methotrexate and that thymidine salvage may represent a mechanism for clinical resistance to methotrexate. These results also suggest that a high dose dipyridamole regimen can be used as a pharmacological approach to test the role of nucleoside membrane flux on the clinical action of other standard chemotherapeutic drugs. Phase II studies testing the clinical efficacy of this combination should use a methotrexate dose of 60 mg/m2 with a provision for methotrexate dose escalation based upon individual patient tolerance.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1989

Liver transplantation in children: University of Louvain Medical School (Brussels) experience with the first 139 patients.

The children's liver transplantation program at the University of Louvain Medical School in Brussels has been organized with a multidisciplinary pediatric approach. The age distribution of the first 139 patients transplanted between March 1984 and June 1989 is characterized by the distinct preponderance of infants and small children (62.5% younger than 3 years, 16 younger than 1 year). Biliary atresia unalleviated by the Kasai portoenterostomy or its modifications was the single most frequent indication (101 cases) followed by the heterogenous group of metabolic diseases (17 cases). Two children underwent combined liver and kidney transplantation. A prominent feature of this series is the routine use of the reduced-size liver (40% of the 171 grafts) to alleviate the shortage of size-matched pediatric donors. The actuarial survival rate of the 139 children was 75.8% at 1 year and 72.4% at 2 years and thereafter. For patients who received 1 graft electively, the 1-year survival rates were 85.2% and 92.5% for those who received a full-size or a reduced-size liver with the same proportion (83%) of long-term surviving patients having normal liver tests. Long-term survival rates were not influenced by age, except for infants younger than 1 year with 62.4% surviving at 1-year posttransplantation. This latter group included a vast majority (14 of 16) of severely debilitated biliary atresia cases in preterminal condition. Graft loss from rejection was kept at a low rate of 5.2% (acute in 5-2.9% and chronic in 4-2.3%).

Adolescent↗
PubMed1988

Phase I clinical trial of a combination of dipyridamole and acivicin based upon inhibition of nucleoside salvage.

A Phase I clinical trial of simultaneous 72-h infusions of dipyridamole and acivicin was carried out in patients with advanced malignancies. The objective of this trial was to determine the maximum tolerated dose of dipyridamole when administered as a 72-h infusion in combination with acivicin. The development of this combination is of interest because of in vitro observations which demonstrate that dipyridamole potentiates the cytotoxic action of acivicin by blocking nucleoside salvage. Patients were treated with concomitant i.v. infusions of dipyridamole and acivicin for 72 h. The acivicin dose infused remained constant during the trial at 60 mg/m2/72 h. The maximum tolerated dose (MTD) of dipyridamole was 23.1 mg/kg/72 h. Limiting toxicities at the MTD of dipyridamole with acivicin were severe gastrointestinal and constitutional symptoms which appeared to be caused by the high doses of dipyridamole administered. Escalation of dipyridamole did not potentiate the mild myelosuppression or the neurotoxicity which occurs with acivicin alone. At a dose of dipyridamole which was well below the MTD, one patient experienced symptomatic orthostatic hypotension, and another patient with coronary artery disease developed dizziness and transient electrocardiogram abnormalities. However, no other hypotensive or cardiovascular events occurred as dipyridamole was escalated to the MTD. Phlebitis occurred at the site of infusion when the dose of dipyridamole exceeded 13.5 mg/kg/72 h. Because of this local toxicity, it was necessary to administer dipyridamole through a central venous catheter to achieve maximum plasma levels. At the MTD of dipyridamole, steady-state total and free plasma levels of 11.9 microM and 27.8 nM, respectively, were attained by 24 h. These are free dipyridamole levels which in vitro were sufficient to block cytidine salvage and to potentiate the biochemical and cytotoxic effects of acivicin against human colon cancer cells (P.H. Fischer et al., Cancer Res., 44:3355-3359, 1984).

Antineoplastic Combined Chemotherapy Protocols↗