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Biomedical subjects

G Calabrese

Publications and source records attributed to G Calabrese.

At least 199 records · Page 11Linked to original sources
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Kinetics and metabolic activity of biosynthetic NPH insulin evaluated by the glucose clamp technique.

The glucose clamp technique has been used to evaluate the metabolic activity of NPH biosynthetic insulin in diabetic subjects free from anti-insulin antibodies. After overnight blood glucose normalization with a glucose-controlled insulin infusion system (Biostator), an s.c. injection of NPH insulin was given in the abdominal region. The insulin dose (0.236 +/- 0.05 U/kg body wt) was related to the usual intermediate-acting insulin requirement in the morning. Glucose was clamped at 100 mg/dl by a feedback i.v. glucose infusion. The end of the action of s.c. injected insulin considered conventionally to be the time of the spontaneous rise of blood glucose to 110 mg/dl. Free insulin levels were higher and the length of action was longer after NPH porcine than after NPH biosynthetic human insulin (BHI) (area under the free insulin curve: porcine 1423 +/- 556 mU/L/h; BHI 1045 +/- 338 mU/L/h, P less than 0.05; length of action: porcine 16.0 +/- 3.2 h; BHI 13.7 +/- 0.9 h, P less than 0.05); the glucose requirement was higher after porcine (76.8 +/- 13.5 g) than after BHI (58.5 +/- 14.6 g) without reaching statistical significance. However, the metabolic activity of the bioavailable insulin (index of plasma free insulin activity) was similar for the two insulins (porcine 381 +/- 77.4, BHI 342.8 +/- 54.2 mU/L/g of glucose/h). We conclude that a difference in pharmacokinetics exists between NPH BHI and porcine NPH insulin, which makes the latter metabolically more active. The different behavior does not seem to be related to the insulin molecule itself but could be a consequence of the unequal content of protamine in the two pharmacologic preparations.

Adult↗
PubMedDate not supplied

[C-reactive protein and homocysteinemia in patients undergoing on-line hemodiafiltration].

PURPOSE: In renal disease therapy (RDT) patients, high plasma homocysteine (tHcy) is common and high C-reactive protein(CRP) levels can be observed, attributed to the inflammatory process caused by the dialysis itself. Hyperhomocysteinemia and bioincompatibility are considered independent vascular risk factors. This study evaluated the behavior of these parameters in patients undergoing on-line hemodiafiltration (OL-HDF). METHODS: In 56 patients, HDF was performed using high permeability polyamide membranes, exchanging in the post-dilution mode 16-18 L/session of a reinfusate obtained by the on-line system (triple filtration AK200, Gambro). CRP was measured by an immunological method at the start and the end of the session in patients without comorbidities (group 1, n=30)and with inflammatory diseases (group 2, n=26). In 23 of the 56 patients, tHCY was measured (by high performance liquid chromatography (HPLC)) before and after the mid-week session on different schedule of folinic acid, vitamin B12 and vitamin B6. RESULTS: Pre-dialytic CRP was in the normal range in group 1 patients, whereas it was higher in group 2 patients; dialysis did not induce a significant change in either group. The intradialytic percentage tHcy decrease was approximately 50% regardless of the pre-dialytic value, which was significantly different according to the vitamin supplements administered. CONCLUSIONS: HDF, as performed in this study, demonstrated biocompatibility and efficient Hcy removal; therefore, it can prevent cardiovascular disease (CVD) in patients on regular extracorporeal dialysis.

Aged↗
PubMedDate not supplied

[Cytogenetic study of 201 subjects with altered reproductive fitness].

The A. report a cytogenetic study performed on 201 subjects with a defective reproductive fitness. In total, they detected 37 chromosomal changes (18.4%): 7 in 48 subjects (24 couples) with sterility (14.5%), 11 in 96 with hypogonadism and/or criptorchidism (11.4%), 15 in 38 women with oligoamenorrhoea (39.4%) and 4 in 4 patients with Morris syndrome (100%). On the contrary, no chromosomal change was detected in 15 patients with pure gynecomastia. The A. discuss the significance of these chromosomal aberrations, and particularly: the mosaicism XO/XX, because this chromosome picture may be associated with fertility, as in our case; the isodicentric X, because the patient showed the clinical features of the Turner's syndrome; the inv(11), because the patient showed a progressive oligoamenorrhoea, leading us to retain that some chromosome changes, by determining a severe gametic selection, may cause infertility in these subjects. the t(13;14), detected in men with azoospermia, because these changes confirm the presence of a gametic selection, mostly in men. Therefore, according to other reports, the A. suggest that the cytogenetic investigations should be performed in all subjects with abnormal reproductive fitness, for a more accurate diagnostic iter.

Adult↗
PubMedDate not supplied

[Hemodiafiltration with high-level ultrafiltration versus hemodialysis. Longitudinal study].

A group of well nourished young patients was examined during 2 longterm consecutive high efficiency dialytic schedules to detect possible clinical and biochemical differences. The patients were first studied during hemodialysis with a 1.2 m2 cuprophan membrane and blood flow of 400 ml/min and, then, during hemodiafiltration with an ultrafiltration rate greater than 100 ml/min by using high permeability membranes with a surface greater than or equal to 1.4 m2. As expected by the higher clearances obtained on hemodiafiltration, this technique resulted in a significant reduction of dialysis time and of BUN and serum creatinine, associated with a significant increase of hemoglobin, possibly related to a better deintoxication. Furthermore, the dry body weight decreased significantly during hemodialysis, whereas it increased significantly during hemodiafiltration, despite unchanged dietary habits, indicating possible differences in the nutrients utilization during the 2 dialytic schedules. Therefore, in chronically dialyzed patients, highly permeable synthetic membranes should be preferred to cuprophan because of a supposed better biocompatibility and should be used with the highest ultrafiltration rate in order to obtain a better dialytic efficiency and to avoid the risk of backfiltration.

Adult↗