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Biomedical subjects

G Ambroso

Publications and source records attributed to G Ambroso.

At least 19 recordsLinked to original sources
PubMed1995

Atrial natriuretic peptide and hemodynamic changes during normal human pregnancy.

We compared plasma atrial natriuretic peptide (ANP) and cGMP levels during normal pregnancy--a condition characterized by hypervolemia, high cardiac output, and decreased vascular resistance--with postpartum levels and assessed their relation to pregnancy-induced hemodynamic changes. Humoral and hemodynamic variables were measured in healthy women subjects in the supine and upright postures at each trimester of pregnancy and postpartum. Supine plasma ANP was increased throughout pregnancy (32 +/- 5, 21 +/- 3, and 19 +/- 2 versus 15 +/- 1 pmol.L-1, respectively, at each trimester versus postpartum), as was cGMP (8.6 +/- 1, 7.1 +/- 1, and 6.6 +/- 1 versus 5.6 +/- 1 nmol.L-1), and their increments were directly related (r = .68, P < .01). Both ANP and cGMP levels did not differ from postpartum levels after subjects stood. Supine stroke volume was initially increased but declined below postpartum levels in late pregnancy (69 +/- 4, 60 +/- 3, and 44 +/- 3 versus 58 +/- 4 mL.m-2), whereas after subjects stood it was always higher (56 +/- 3, 58 +/- 3, and 49 +/- 2 versus 44 +/- 2 mL.m-2); thus, stroke volume tended to increase in response to standing in late pregnancy. Supine cardiac index had a similar trend, which was opposite to that of total peripheral resistance (1213 +/- 62, 1265 +/- 79, and 1729 +/- 89 versus 1654 +/- 92 dyne.s-1.cm-5.m-2).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Validation study of thoracic fluid bioimpedance for assessing the haemodialysis-induced changes in total body fluids.

Thoracic fluid bioimpedance (TFB) has been proposed as a noninvasive technique for monitoring both haemodynamics and fluid homeostasis in patients on regular dialysis. To validate the reliability of TFB in assessing the haemodialysis (HD)-induced changes in plasma volume (PV) in these patients, we examined the changes of TFB during and after HD in relation to those in total plasma protein (TP) concentration, haematocrit (Ht), heart rate (HR), total body water (TBW) and plasma angiotensin II (A-II) concentration. Data were recorded in 13 HD patients with a wide range of interdialytic weight gains before, at the end, and 4, 8, 24, 48 h after the HD session. We found that the percent TFB changes were closely and inversely related with those of TP, Ht and TBW (r = -0.54, r = -0.45 and -0.68, respectively, p < 0.001 for all). Similar relations were found between the percent changes in TFB and those in absolute TP and Ht. In addition, a direct relation was found between the percent changes of TFB and those of HR and of A-II (r = 0.33 and r = 0.31, respectively, p < 0.01 for both). These data indicate that TFB is a reliable method for evaluating the HD-induced changes of intra- and extravascular fluids and, with respect to the conventional techniques, has the advantage of providing this information dynamically, and in conjunction with the haemodynamic data of patients.

Adult↗
PubMed1993

Abnormal hemodynamics and elevated angiotensin II plasma levels in polydipsic patients on regular hemodialysis treatment.

To investigate the cause and the mechanisms responsible of the compulsive thirst and excessive fluid intake observed in many patients on chronic dialysis treatment, we measured plasma antidiuretic hormone (ADH), angiotensin II (Ang II) and some hemodynamic parameters in seven polydipsic and in six normodipsic patients before hemodialysis, at the end of it and several times during the interdialytic interval. Before dialysis we found that ADH was elevated in both groups (6.9 +/- 1.9 vs. 6.9 +/- 1.3 pg/ml, respectively in polydipsics and controls), whereas Ang II was abnormally high only in polydipsics (51 +/- 12 vs. 11 +/- 3 pg/ml, P < 0.01); these patients also had significantly higher heart rate and cardiac indices and lower total peripheral resistances than control patients. Overall these hemodynamic indices were related with Ang II but not with ADH. Ang II rose markedly in polydipsics after dialysis, reaching a peak at the fourth hour after its termination (136 +/- 12 pg/ml) and remained consistently elevated throughout the interdialytic period, whereas in controls Ang II was practically unchanged with respect to baseline. In contrast, ADH had minor and similar modifications in both groups, in whom also the hemodynamic changes were superimposable. Significant correlations were found between the absolute and percent changes of Ang II and those of plasma volume during the interdialytic interval (P < 0.001 for both), and between the individual values of Ang II measured during the whole study and the interdialytic weight gain (P < 0.05). These results demonstrate that polydipsic patients have abnormally high levels of Ang II before and after the hemodialysis-induced volume depletion.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Aminoglutethimide in advanced breast cancer: plasma levels and clinical results after low and high doses.

Drug plasma levels, metabolism data and clinical results were evaluated after the daily administration of either 500 or 1,000 mg aminoglutethimide (AG, Orimeten, Ciba-Geigy) plus hydrocortisone acetate (20 mg b. i. d.). A total of 34 patients with advanced breast cancer entered the study: 17 were given 1,000 mg/day and 17 received 500 mg/day for at least 3 months. A novel HPLC method was developed to determine the levels of AG and its known metabolites [N-acetyl-AG (NAG), formyl-AG, nitroglutethimide, hydroxy-AG] in the biological samples. AG plasma concentration was significantly higher during the 1,000-mg/day regimen. NAG was the only metabolite observed in plasma, always occurring at concentrations lower than those of the parent drug. The ratios between NAG and AG levels distinguish two statistically different groups of patients. Irrespective of the dose, a partial response was observed in 44% of the patients; no change in 32% of cases; and progressive disease had an incidence of 24%. The probability of response was not dependent on the drug AUC or on the NAG/AG ratio and did not significantly depend on previous hormone treatment. Neither the plasmatic level of the AG or metabolite concentrations nor the NAG/AG ratio seemed to affect the incidence of side effects.

Adult↗
PubMed1991

Plasma active and inactive renin and fetal complications in women with high risk pregnancies.

To examine whether the activation of the renin system, which occurs during pregnancy, may be relevant for the development and the outcome of the fetus, we measured active and inactive renin throughout gestation in 29 women having a pregnancy defined as "high risk" because of a clinical history of hypertension, nephropathy, and unexplained abortions. In 23 of these women who delivered full-term infants with normal weight and status, we found that active renin increased progressively from early pregnancy until the end of the second trimester and then declined slightly thereafter. In contrast, in the remaining six women who had fetal complications consisting of either signs of distress requiring cesarean section or growth retardation, the increase in active renin failed to occur. In all women the levels of inactive renin were more elevated throughout gestation than those observed in nonpregnant women, and were higher, although not significantly, in women without fetal complications than in those with fetal complications. Thus, a blunted activation of the renin system during pregnancy is associated with alteration in fetal development and may possibly contribute to it.

Adult↗
PubMed1989

Partial correction of chromosome instability in Fanconi anemia by desferrioxamine.

The action of the iron chelator desferrioxamine (DFO) on the cytogenetic pattern of cultured lymphocytes from Fanconi anemia (FA) patients was investigated. The addition of 10(-4) M DFO throughout the culture time resulted in a 50% reduction of the spontaneous chromosome breakage of FA cells. In addition, the clastogenic action of diepoxybutane on FA lymphocytes was also partly counteracted by DFO. The above findings support the assumption that one of the mechanisms involved in the pathogenesis of FA might be an impaired capacity of the cells from such patients to remove active oxygen species. The relationship between intraleukocyte chelatable iron pool and free radical formation in FA subjects is discussed.

Anemia, Aplastic↗
PubMed1989

Effect of oral zinc administration on prolactin and thymulin circulating levels in patients with chronic renal failure.

High serum PRL and low zinc (Zn) levels are common findings in patients with chronic renal failure (CRF); in such patients serum Zn concentrations have been reported to be inversely correlated to serum PRL levels. Moreover, Zn regulates both thymus growth and the biological activity of the thymic hormone thymulin, and PRL-thymic interrelationships have been described. To determine whether hypozincemia alters serum PRL and plasma thymulin concentrations in CRF, 9 men with CRF treated by chronic hemodialysis were given 400 mg/day Zn sulfate, orally (4.96 meq/day Zn), for 6 months. Before treatment, serum PRL levels were significantly higher (P less than 0.001) in these patients than in normal men [mean, 28.7 +/- 20.7 (+/-SD) vs. 7.5 +/- 3.7 micrograms/L], and their serum PRL response to TRH (200 micrograms, iv) was impaired (mean maximal percent increase, 38.2 +/- 10.9 vs. 641 +/- 335; P less than 0.001). The plasma Zn-bound bioactive thymulin titer (1.3 +/- 0.7 1/log2), total thymulin titer (Zn-bound plus Zn-unbound forms, 2.1 +/- 0.8 1/log2), and serum Zn (13.1 +/- 2.4 mumol/L) were lower (P less than 0.001) in men with CRF than in normal men. Zn therapy did not induce any significant change in basal and TRH-stimulated serum PRL levels, while serum Zn levels significantly increased, reaching the normal range after the first week of treatment (17.8 +/- 6.3 mumol/L). Plasma total thymulin increased rapidly, reaching normal levels after 1 week, but Zn-bound thymulin increased modestly during the first month of treatment and more after 3 and 6 months of treatment. There was no age-related difference in plasma thymulin levels during therapy. We conclude that oral Zn administration in patients with CRF significantly increases both total and Zn-bound thymulin, but does not modify basal and TRH-stimulated serum PRL levels. The observation that Zn supplementation markedly increased plasma thymulin levels in uremic patients suggests that Zn is a potent stimulus for thymic hormone synthesis, and it can reverse the age-related diminution of thymic activity in CRF patients.

Adult↗
PubMed1989

Low-dose aminoglutethimide plus steroid replacement in advanced breast cancer patients resistant to conventional therapies.

In an attempt to define the activity and toxicity of low-dose aminoglutethimide plus steroid replacement in advanced breast cancer, we treated 40 patients with aminoglutethimide 500 mg/day + hydrocortisone 50 mg/day. Previous treatment consisted of additive hormones in 29 patients, oophorectomy in 8, and chemotherapy in 32. Among the 37 patients evaluable for response and toxicity, 5 objective responses (16.2%) and 20 stable diseases (54%) were noted. Toxicity, absent in 23 patients (62.1%) and mild in 14, consisted mainly of Grade I (WHO) nausea, drowsiness, cutaneous rash, and dizziness. Responders and patients with stable disease experienced a similar survival (median not reached at 22 months). Aminoglutethimide at low doses appears to be beneficial in patients refractory to conventional therapies even if the objective response rate is low.

Adult↗
PubMed1989

[Type A behavior and psychological characteristics of hypertensive patients undergoing antihypertensive treatment].

The aim of this study was to evaluate the presence of "type A" behaviour and possible psychological distress in 373 hypertensive patients. One-hundred and ninety-five males, 56.2 +/- 6.2 years old and one-hundred and seventy-eight females, 57.1 +/- 6.2 years old, coming from the IPPPSH and still under double-blind treatment with or without a beta-blocker (oxprenolol 160 mg SR), were studied by means of the Jenkins Activity Survey form C and several tests from the Cognitive Behavioural Assessment Battery (CBA-2.0). Seventy-four point eight percent of the patients showed a "type A" pattern, and 25.5% were in the extreme predictive interval for coronary heart disease according to WCGS. "Type A" pattern was not influenced by variables such as age, sex, education, job or previous pharmacological treatment. The patients studied did not show any particular psychological distress at the psychometric evaluation. However, special social and cultural characteristics and different therapies influenced some symptoms, such as anxiety, depression and somatic lamentation. According to this study: "type A" behaviour seems to be a steady feature of the hypertensive patient; furthermore, it seems to be due to a "biological imprinting" which can be considered a cause of hypertension; psychological distress depends on a particular set of environmental stimuli. In the first case an accurate prevention is needed while, in the second case adequate pharmacological and/or psychological therapies are needed.

Aged↗
PubMed1986

Pregnancy in women with chronic renal failure.

We describe 19 pregnancies in 18 women with chronic renal disease and plasma creatinine greater than or equal to 1.6 mg/dl before pregnancy. There were 2 spontaneous abortions (11th and 21st week), 2 therapeutic abortions (18th and 19th week), 1 stillbirth (30th week), 1 neonatal death (31st week) and 13 live births, 7 of them were preterm. Nine cesarean sections were done. Serial determinations of plasma creatinine during pregnancy showed a trend to decrease during the first half and to increase during the second half of pregnancy. The effect of pregnancy on the progression of renal failure was evaluated in 14 patients by comparing the linear regression lines of reciprocal plasma creatinine versus time before and after pregnancy. In 5 patients the rate of progression worsened after pregnancy. Our data indicate that women with chronic renal failure may have a successful pregnancy, but one third of them will have an accelerated rate of progression of the disease.

Abortion, Spontaneous↗
PubMed1981

One year efficacy and tolerability of oxprenolol slow-release and chlorthalidone on fixed combination in mild to moderate hypertension.

The long-term antihypertensive efficacy and tolerability of a fixed combination of oxprenolol 160 mg slow-release + chlortalidone 20 mg was studied in 40 out-patients with mild to moderate essential hypertension followed during one year with monthly clinical visits. The fixed combination was given at the dosage of 1 tablet once daily, in the morning, increasing to 1 tablet b.i.d. in case of lying diastolic blood pressure greater than 95 mmHg. After one year only 9 patients were on 1 tablet b.i.d., the others remaining on 1 tablet once daily regimen. Clear-cut antihypertensive effect was already evident after the 1st month of treatment. Both systolic and diastolic blood pressure further decreased after two months (p less than 0.01) showing then a constant trend to decrease till the 6th month; afterwards blood pressure values remained unchanged. Normalization of blood pressure was obtained in 63%, 73% and 80% of the patients, respectively after 1, 6 and 12 months of treatment. Laboratory data did not show significant changes. Only 3 patients complained of unwanted effects which were mild, transient and in no case compelled to interrupt the treatment. Results confirm that the fixed combination of oxprenolol 160 mg slow-release + chlorthalidone 20 mg is able to long term control mild to moderate hypertension with a good tolerability, thus allowing an improved patient compliance.

Adult↗
PubMed1980

Reversible acute renal faiure in diffuse scleroderma.

A case of severe hypertension and acute renal failure developing in a 56 year old woman affected by diffuse scleroderma is reported. The patient was treated by peritoneal dialysis, antihypertensive agents and plasma infusions, which led to the correction of arterial hypertension and partial recovery of renal function. This report emphasizes the possibility that the correction of malignant hypertension may prevent progressive renal falure in some patients affected by diffuse scleroderma.

Acute Kidney Injury↗
PubMed1979

[Anti-edema activity of injectable Venoruton in abdominal surgery].

The anti-oedema activity of an injectable drug (HR; active principle: 0-(beta-hydroxyethyl)-rutoside) was assessed in 60 gastric extrahepatic bile duct, and large intestine surgery patients (30 being used as controls). Gastroscopy (with biopsy), gastroduodenoscopy, colonoscopy (with biopsy) and radiological examination were usually performed on the 5th and 10th post-operative days. The drug showed significant therapeutic effects: rapid resolution of oedema, especially at the sutures, leading to early cicatrisation, canalisation and the prevention of dehiscence. Finally, duration of hospitalisation was less than in the untreated cases. The gastroscopic, radiographic and biopsy findings are considered to have shown clear evidence of the drug's action against oedema formation.

Adult↗