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Biomedical subjects

M L Bianchi

Publications and source records attributed to M L Bianchi.

At least 37 records · Page 2Linked to original sources
PubMed1994

Calcitriol and calcium carbonate therapy in early chronic renal failure.

The aim of this study was to evaluate the effects of a combined low-dose therapy of calcitriol and calcium carbonate on bone metabolism in the early phases of chronic renal failure. A 30-month study involving 17 patients with ECRF was made: 6 months of observation were followed by 24 months of therapy (calcitriol 0.25 microgram/day plus calcium carbonate 1 g/day). The most important results were that renal function was stable throughout the study and there was an increase in calcaemia and a decrease in plasma alkaline phosphatase, plasma osteocalcin, plasma PTH and urinary hydroxyproline. We observed a progressive slowing of the rate of loss of appendicular bone density as well as a decrease of osteoblastic and osteoclastic activity and an improvement of bone mineralization. In conclusion, low doses of calcitriol plus calcium carbonate seem to improve the biochemical and bone derangements in early renal failure.

Adult↗
PubMed1993

Unilateral nephrectomy and progression of renal failure.

Extensive ablation of renal mass in experimental animals leads to progressive glomerulosclerosis and chronic renal failure (CRF). Clinical studies are far from answering the question whether patients with reduced renal mass are at risk of developing progressive CRF. The aim of our study was to examine the morphological and functional aspects of the remnant kidney in a group of patients who underwent unilateral nephrectomy for renal tuberculosis: 313 patients (161 M, 152 F) mean age 57.2 +/- 10.7, were examined after a period ranging from 13.56 to 591.2 months. All patients were on ad libitum diet. Hypertension was found in 34.19% of the patients; SBP was 155.29 +/- 19.9 mmHg and DBP was 92.74 +/- 13.07 mmHg. Estimation of renal size performed by ultrasound scanner gave the following results: length 116.78 +/- 8.99 mm; width 58.24 +/- 7.21 mm; thickness 17.88 +/- 1.96 mm. Kidney function assessed by serum creatinine levels showed a mean level of 1.28 +/- 0.53 mg%. Forty-two patients (13.41%) had serum levels > 1.5 mg% but 18 of them had nonconcomitant systemic or renal involvement. Microalbuminuria determined by RIA assay was found in 50.5% of the patients. In our group of patients renal functional impairment was low and hyperfiltration expressed as microalbuminuria does not appear to be a primary factor in the progression of renal failure.

Creatinine↗
PubMed1992

Bone mass status in different degrees of chronic renal failure.

Bone mineral density (BMD) was evaluated in 69 patients with chronic renal failure (CRF) and in healthy controls matched for age, sex, and, for women, menopausal status. Both appendicular (predominantly cortical) and axial (predominantly trabecular) bone mass were measured. Appendicular BMD was measured by single photon absorptiometry on the distal forearm and axial BMD was measured by dual photon absorptiometry on the lumbar spine. Patients were divided into three groups on the basis of creatinine clearance: group 1, 58 to 36 ml/min; group 2, 30 to 18 ml/min; group 3, 15 to 9 ml/min. Both appendicular and axial BMD decreased with the worsening of renal failure. Parathyroid hormone levels were inversely correlated with the values of appendicular BMD. BMD values were significantly lower in postmenopausal than in premenopausal women. Months of menopause were inversely correlated with axial BMD values. Appendicular BMD was lower in CRF patients than in controls, and both appendicular and axial BMD were significantly lower in postmenopausal uremic women than in postmenopausal healthy women.

Absorptiometry, Photon↗
PubMed1991

Age, time since menopause, and body parameters as determinants of female spinal bone mass: a mathematical model.

The study of mathematical models to describe bone mass behavior throughout life is a possibility for assessing the main factors of peak bone mass and bone loss. We developed a mathematical model to predict spinal bone mass behavior on a sample of 181 healthy Italian women whose lumbar bone mineral content was determined by Gd-153 dual photon absorptiometry. This model proved to be both efficient, showing the best fit (r = 0.7 on spinal bone mineral content) when compared to other previously suggested models, and also reliable as its fit remained the best when applied to a subsequent sample of 519 women whose lumbar spine was measured by dual X-ray photon absorptiometry. This model suggests that body height and body weight (but not age) are determinants of bone mass in premenopausal women. In postmenopausal women, an accelerated phase of bone loss starting at menopause is dependent on age and time since menopause, whereas body mass index acts as a protective factor. This model confirms the influence on spinal bone mass not only of age and time since menopause but also of body size parameters.

Absorptiometry, Photon↗
PubMed1991

Acute effects of calcitriol and phosphate salts on mineral metabolism in children with hypophosphatemic rickets.

We investigated the acute effects of oral administration of 1,25-dihydroxyvitamin D (1,25-(OH)2D) and phosphate on the major mineral metabolism indexes in six children with vitamin D-resistant rickets treated with a long-term regimen of phosphate and calcitriol. Two acute tests were performed in which plasma calcium, phosphate, immunoreactive parathyroid hormone (iPTH) (intact molecule), 25-hydroxyvitamin D (25-OHD), and 1,25-(OH)2D levels were measured: the first after an oral phosphate load (20 mg/kg) was administered after calcitriol had been discontinued for 10 days, and the second after a calcitriol load (0.03 microgram/kg) plus the same phosphate load but with the children receiving the usual combination treatment. There were no significant differences in basal levels of calcium, phosphate, iPTH, 25-OHD, or 1,25-(OH)2D between the two tests, nor were delta percent calcium and 25-OHD values significantly different. The delta percent plasma phosphate concentration at 60 minutes was significantly higher during test 2 than during test 1 (p less than 0.01) and delta percent iPTH concentration at 60 minutes was significantly higher during test 1 than during test 2 (p less than 0.01). In test 2 the iPTH level returned to baseline at 180 minutes. Higher delta percent 1,25-(OH)2D values at 60 minutes were observed in test 2 than in test 1 (p less than 0.01). Furthermore, the delta percent 1,25-(OH)2D levels were still higher at 180 minutes in test 2 than during test 1 (p less than 0.01). Our study indicates that oral calcitriol has an inhibitory effect on iPTH secretion in the hours immediately after oral phosphate administration in children with vitamin D-resistant rickets.

25-Hydroxyvitamin D 2↗
PubMed1991

Spinal and forearm bone mass in relation to ageing and menopause in healthy Italian women.

Most studies concerning bone status have been performed in Nordic and Anglo-Saxon countries and few data are available on southern European populations. We performed a cross-sectional study on spine and forearm bone mass in 234 healthy Italian women and related the results to age and time since menopause. Forearm bone mass does not decline in premenopausal age, whereas, as far as the spine is concerned, a significant reduction appears 3 years before the mean age of menopause; in both cases, the occurrence of menopause accounted for an accelerated phase of bone loss. In postmenopausal women both spine and forearm bone mass show a stronger correlation with years since menopause than with age. According to a linear exponential model, the rate of spinal bone loss per year since menopause is around 4% in the first 3 years which slows down to around 2% in the 5th year; the corresponding rates of forearm bone loss are 2% and 1.3%, respectively.

Adult↗
PubMed1991

[The use of drinking water as a vehicle of nutrients: experimental studies with iron].

This investigation is part of a large project, the objective of which is to study the possibility of utilizing drinking water as a carrier of nutrients, such as iron. Various iron salts and in different concentrations, were added to water and tested for their effect on color and turbidity. The bioavailability of various forms of iron salts added to drinking water was tested using the rat bioassay technique. The results of this study indicated that ferric ammonium citrate changed very little the color and turbidity of the water solutions. It was considered the best suitable form of iron to be added to drinking chloride water. Ferric ammonium citrate, ferrous sulfate and ferrous gluconate were all found effective in preventing rat anemia when added to their drinking water.

Anemia, Hypochromic↗
PubMed1990

Bone metabolism in juvenile rheumatoid arthritis.

Plasma and urinary indexes of bone metabolism were studied in 36 children affected by juvenile rheumatoid arthritis (JRA) during 1 year, in order to evaluate the calciotropic hormone levels and bone mass. Children were divided in three groups according to the subtype of JRA: pauciarticular, polyarticular, systemic. Patients of the latter two groups were on corticosteroid treatment. A control group of healthy children (matched for age and sex) was compared. Children affected by pauciarticular disease did not show any difference with respect to controls. In the polyarticular and systemic groups, basal observation revealed decreased levels of 25(OH)D, significantly lower (P less than 0.01) with respect to the control and pauciarticular groups. After one year, 25(OH)D showed a further decrease in the systemic group, while PTH levels were increased. Moreover, bone mineral density values in systemic JRA were significantly lower than values of a matched control group and did not increase as expected during the year. It seems thus possible that severe JRA has an influence on bone mass, perhaps mediated by a decrease in active vitamin D metabolites.

Adolescent↗
PubMed1990

Effects of calcifediol treatment on the progression of renal osteodystrophy during continuous ambulatory peritoneal dialysis.

Mineral metabolism was studied in 31 patients with chronic renal failure on continuous ambulatory peritoneal dialysis (CAPD) for a year. After baseline observations, 1-year calcifediol treatment was started in all the patients (100 micrograms/day). After therapy, progressive normalization of calcium levels was found in all the patients, while plasma phosphate did not change. After therapy, plasma alkaline phosphatase and parathyroid hormone decreased significantly. 1,25-Dihydroxyvitamin D showed a slight increase, and 25-hydroxyvitamin D (extremely low at the start of the study) rose, reaching normal levels, after 1 year of treatment. Bone mineral density and bone biopsy indexes showed general improvement after calcifediol. In conclusion, calcifediol seems to act positively on the disorders of mineral metabolism in CAPD.

Alkaline Phosphatase↗
PubMed1989

Growth in young children with chronic renal failure.

Statural growth and its relation to growth potential, renal function, blood urea nitrogen (BUN), mineral metabolism hormones and dietary intake were studied in 17 prepubertal children (aged 1.6-9.3 years) on conservative treatment for chronic renal failure due to tubulo-interstitial nephropathy. Statural growth (height SDS) was related to the degree of renal failure, was more retarded than ossification, and was independent of the chronological age of the patients. We observed that the lower the glomerular filtration rate (GFR), the lower was the growth potential (increased bone age/statural age ratio). Growth velocity may be normal regardless of statural and bone maturation delay and the degree of renal insufficiency. Impaired growth rate correlated with parathyroid hormone levels, caloric intake and increased blood urea nitrogen during the year of observation. These data show that comprehensive monitoring and suitable treatment must be performed in order to prevent growth retardation at any GFR level.

Blood Urea Nitrogen↗
PubMed1987

Failure of platelet markers to evaluate membrane biocompatibility during a combined hemodialysis-hemoperfusion treatment.

Plasma levels of the platelet markers beta-thromboglobulin (beta-TG) and platelet factor 4 (PF4) are among the most sophisticated indexes of biocompatibility available to evaluate new members for hemodialysis. This investigation was designed to determine the extent of platelet activation by measuring the alpha-granule release products, beta-TG and PF4; anticoagulation and thrombogenesis by monitoring plasma heparin; and fibrinopeptide A (FPA) and thromboxane B2 (TX B2) levels during treatment with a combined hemodialysis-hemoperfusion system. Both in vivo and in vitro results showed that the platelet markers had a pattern different from that generally observed during treatment with hemodialysis alone. This is due to the avidity of charcoal for the markers studied, which therefore cannot be used to evaluate the biocompatibility of the system.

Biocompatible Materials↗
PubMed1987

Serum amylase and isoamylase in chronic renal failure.

In 37 patients with chronic renal failure (CRF) serum amylase was higher than in 33 normal subjects (483 U/L +/- SD 185 versus 267 +/- SD 66 U/L, p less than 0.05); while the percentage of pancreatic isoenzymes was within normal limits in 34 patients and only slightly increased in 3. Seventeen of the patients were on conservative treatment, 10 on hemodialysis and 10 on continuous ambulatory peritoneal dialysis; no significant differences in serum amylase levels were detected between these subgroups. No correlation was found between serum BUN or creatinine and serum amylase but a positive correlation was found between these enzyme levels and duration of CRF (p less than 0.05) in the patients on conservative treatment.

Adult↗
PubMed1986

Effects of 1,25-dihydroxyvitamin-D3 treatment on mineral balance in children with end stage renal disease undergoing chronic hemofiltration.

Ten children with end stage renal disease on chronic hemofiltration (HF) were studied for a 1-yr period to evaluate the efficacy of 1,25-dihydroxyvitamin-D3 (1,25(OH)2D3) therapy on biohumoral parameters of renal osteodystrophy and bone mineral content. In six of these children an acute study was done of the direct effect of the HF procedure on calcium and phosphate balance during 12 HF sessions. During the first 6 months of the study all children were treated with 1,25(OH)2D3 (0.25-0.50 microgram/day) to maintain plasma calcium at 9.5-11.0 mg/dl. There was a significant increase in plasma calcium (p less than 0.05) and a significant decrease in plasma phosphate (p less than 0.01) and alkaline phosphatase concentrations (p less than 0.05). The circulating levels of NH2 immunoreactive parathyroid hormone did not change, remaining at the upper limits of reference values. Immunoreactive parathyroid hormone-COOH terminal fragment levels decreased significantly (p less than 0.05). Bone mineral content rose significantly (p less than 0.01). During the last 6 months of the study, to evaluate the possibility that HF alone might control secondary hyperparathyroidism, 1,25(OH)2D3 treatment was discontinued in five children; plasma calcium and phosphate were well controlled whereas hyperparathyroidism worsened in all five, and one also developed intense pruritus and hypertension. The other five children remained on 1,25(OH)2D3 treatment; two of these were transplanted, and the other three continued to show an improvement of mineral balance. The results of the acute study showed that calcium balance was positive with a mean Ca++ gain of 140 mg/HF session. The mean total phosphate removed per HF run was 574 mg.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗