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Biomedical subjects

G Como

Publications and source records attributed to G Como.

28 records · Page 2Linked to original sources
PubMed1985

Treatment of arterial hypertension with nifedipine in patients with chronic renal insufficiency.

The acute and chronic antihypertensive effects of nifedipine were investigated in patients with chronic renal insufficiency (CRI). The acute effects were assessed after the administration either of a fast-release nifedipine capsule or a slow-release nifedipine tablet in 10 and 15 patients respectively. Both the preparations induced prompt and marked reduction of systolic and of diastolic blood pressure, but the capsules showed a shorter antihypertensive effect (2 hours) than tablets (more than 6 hours). The chronic effects of nifedipine tablets given in addition to the previous therapy was assessed in 25 patients with CRI and resistant hypertension. Both systolic and diastolic blood pressure values promptly fell and maintained within the normal range over the whole period of the study (12 months).

Blood Pressure↗
PubMed1979

[Some parameters of cellular immunity in renal transplantation after more than three years].

This paper evaluates the cellular immune system of 16 cadaver kidney transplant recipients more than three years after transplantation. The number and percent of active E rosette forming cells, of E rosette forming cells and of IgG and IgM bearing lymphocytes were determined; the blastogenic response of peripheral blood lymphocytes to PHA and PWM was studied in homologous and autologous serum. Significant alterations of the tests performed were found in patients who had undergone kidney transplant, suggesting a pathogenetic role of chronic immunosuppressive therapy but not excluding other possible factors.

Adolescent↗
PubMed1978

[Behavior of some parameters of humoral immunity in renal transplants after more than 3 years].

This paper evaluates the humoral immune response of 15 cadaver kidney transplant recipients more than three years after transplantation. The study was performed by determining immunoglobulin levels, complement fractions and circulating antigen-antibody complexes. The data obtained suggest that humoral immunity is impaired in patients who have undergone kidney transplant, even after more than three years later. The impairment of immunocompetence may be ascribed both to the immunosuppressive therapy (corticosteroids and azathioprine) and to the transplanted organ itself which represents a chronic antigenic stimulus.

Adolescent↗
PubMedDate not supplied

[Calcimimetics].

Current therapy for secondary hyperparathyroidism in uremia has relatively poor success in achieving the target levels of parathyroid hormone (PTH), calcium and phosphate established by the NKF-K/DOQI guidelines. The discovery and characterization of a new membrane receptor able to sense minimal Ca changes (CaSR) started intensive research in the attempt to characterize better its functions and its finding compounds, which could modulate its activity. CaSR is expressed not only in the cells that secrete calcium-regulating hormones (parathyroid cells and thyroid C-cells) and in cells involved in calcium transport mechanisms (ie intestinal cells, bone-forming osteoblasts, and cells of different nephron segments), but also in other tissues with, as yet, a not completely defined role. CaSR stimulation by the agonists is followed by the activation of a great number of G-proteins mediated intracellular signalling pathways (PLC, PLA, PLD, PKC, PKA, etc). At the level of parathyroid cells, the main effect is the increase in IP3, followed by a mobilization of intracellular Ca stores, which inhibit PTH secretion in a few seconds or minutes. Long-term CaSR stimulation is also able to induce a reduction in both PTH synthesis and parathyroid cell proliferation. More than 100 mutations of the gene coding for CaSR have been described. Some of these mutations are matched by a gain or reduction/loss of function. Notwithstanding, CaSR is widely represented on different tissue cells, the main clinical manifestations of the above genetic changes mainly involve PTH and calcium metabolism. A great number of inorganic and organic cations can interact with the Ca-sensitive N-terminus domain of CaSR, mimicking Ca effects (type I calcimimetics), but these substances have substantial limitations for use in clinical practice. A second class of compounds was produced (NPS R-467, S-467, R-568, S-568, AMG 073), for use in the clinical setting, type II calcimimetics. These compounds, after having interacted with the membrane-spanning domains of the CaSR, induce conformational changes in the N-terminus domain, increasing its affinity for Ca. The preclinical experiences with calcimimetics demonstrated that they were effective in reducing circulating PTH, preventing the progression of secondary hyperparathyroidism, suppressing parathyroid cell proliferation, and reversing osteitis fibrosa at least in animal models. Clinical studies were performed mainly using AMG 073, due to its greater bioavailability and more consistent pharmacokinetic profile. Clinical studies performed in primary hyperparathyroidism proved AMG 073 to be effective in reducing both PTH and Ca serum levels, with a good safety profile. Further studies, mainly focused on the efficacy of AMG 073 in the control of secondary hyperparathyroidism in uremia, confirmed the efficacy of this compound in reducing PTH levels >30% in about 50% of patients. Furthermore, the fall in PTH was matched by a reduction in both calcium and phosphate serum levels of about 5-7%, with a significant reduction in calcium x phosphate product (about 15%). The latter aspect represents a unique pharmacological profile, as compared to all the other available therapeutic means to control secondary hyperparathyroidism in uremia. In addition to their effectiveness, calcimimetics present a relatively safe profile, the only adverse events referred to consist of transient and easily remediable hypocalcemic episodes and some gastrointestinal discomfort symptoms. However, although calcimimetics represent a real advancement in the field of treating secondary hyperparathyroidism in uremic patients, their use should be matched by the awareness that previously the success of a high number of new drugs proposed have been flawed by negative consequences in the long term. Therefore, strict clinical control is necessary in the next few years when the use of these new compounds will widen.

Animals↗
PubMedDate not supplied

[Laboratory parameters as a guide for the radiologic study of infections of the urinary tract in childhood].

Forty-nine children with urinary tract infection aged between 15 days and 10 years were studied. Thirty-three of them (67.3%) had urinary tract malformations. We valued the following parameters: a) White Blood Cells; b) Leukocyte differential; c) ESR at the first hour; d) CRP; e) Concentration ability; f) Body temperature. We wanted to investigate the usefulness of these parameters to predict which patients should be studied by X-ray of urinary tract. Single parameters did not prove very sensitive; the highest correlations were found with ESR and CRP, which were positive in 76% of the cases of malformations. Furthermore we valued the sensitivity and specificity of the tests grouped together: the highest values of sensitivity (97%) and specificity (31%) were obtained coupling the ESR and concentration ability.

Blood Sedimentation↗
PubMedDate not supplied

Comparison of three different tests for assessment of hepatitis C virus in dialysis patients.

OBJECTIVE: To evaluate the relationship between hepatitis C virus antibodies (HCV-Ab) and viremia and to compare the prevalence of HCV-Ab and HCV viremia in hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD) patients. DESIGN: Cross-sectional study. SETTING: Dialysis unit of a nephrology division in a public university hospital. PATIENTS: All dialysis patients who came for routine clinic visits during the study period. None denied informed consent. Forty-eight patients on HD and 79 on CAPD were examined. INTERVENTION: Blood samples were tested by second-generation enzyme-linked immunosorbent assay (ELISA II) and recombinant immunoblot assay (RIBA II) to look for HCV-Ab and by the polymerase chain reaction (PCR) to look for HCV viremia. RESULTS: ELISA II was positive in 52% of HD patients and in 14% of CAPD patients. RIBA II was positive in 48% of HD patients and in 11% of CAPD patients. HCV viremia was positive by PCR in 41.6% of HD patients and in 12% of CAPD patients. Two of these PCR-positive patients did not show HCV-Ab by ELISA II and RIBA II. The sensitivity and specificity of ELISA II were 93% and 92%, the sensitivity and specificity of RIBA II were 86% and 94%. CONCLUSIONS: Our data confirm a higher prevalence of HCV viremia in HD than in CAPD patients. The absence of Ab against virus C in 2 patients positive with PCR might be due to recent HCV infection or to weak virus replication or to a poor immune response.

Alanine Transaminase↗