PubMed HealthSearch

Biomedical subjects

C Ciccarelli

Publications and source records attributed to C Ciccarelli.

At least 19 recordsLinked to original sources

Nutritional and prognostic correlates of bioimpedance indexes in hemodialysis patients.

We carried out a cross sectional and longitudinal study to assess whether bioimpedance indexes (resistance, Rz; reactance, Xc; phase angle, PA) reflect the nutritional status of hemodialysis (HD) patients, and bear a significant association with their long-term survival. The bioimpedance data of 131 patients on chronic HD treatment were compared with those of 272 healthy controls matched for age and sex. Nutritional status was assessed by anthropometric variables, serum albumin (SA), normalized protein catabolic rate (nPCR), and subjective global assessment (SGA). All three bioimpedance indexes varied significantly with HD treatment, however, with the exception of Xc in post-HD, they were on average significantly (P < 0.016) different from controls either pre- and post-HD. Post-HD PA appeared to be the best index of nutritional status, being significantly correlated with SA, age, mid arm muscle circumference (MAMC), SGA, and nPCR (R2 = 0.44; P < 0.01). However, depending on the cut-off levels, PA failed to detect clinically overt malnutrition in one to two thirds of the patients with the worst SGA score. During the follow-up the changes in bioimpedance indexes reflected poorly the changes in dry blood weight, only delta Rz bore a significant correlation (r = 0.29; P < 0.01) with delta body wt. Patients having baseline phase angle values within the lower quartile had a significantly lower two-year survival rate than patients having higher values (59.3% vs. 91.3%; P < 0.01). Cox's analysis (proportional hazard model) showed that phase angle as a predictor of death outweighed all other parameters included in the model (age, SA, nPCR, MAMC, SGA), with a relative risk of 2.6 (95% CI = 1.6 to 4.2). Bioimpedance indexes do not appear to be reliable in detecting clinically overt depletion of lean body mass. However, the strong association of PA with patient survival suggests that this bioimpedance index reflects some dimension of the illness, which is not fully identifiable with the deranged nutritional status.

Adult

Differential modulation of expression of the two acylphosphatase isoenzymes by thyroid hormone.

The modulation of expression of the skeletal muscle and erythrocyte acylphosphatase isoenzymes by thyroid hormone has been investigated. Our results indicate a differential regulation of the two enzymic isoforms by tri-iodothyronine (T3) in K562 cells in culture: an increase in the specific mRNA during T3-stimulation is shown only for the skeletal muscle isoenzyme. A fast and transient T3 induction of the accumulation of the specific mRNA can be observed, reaching a maximum 8 h after hormone treatment and then rapidly decreasing almost to the steady-state level after 24 h. A nuclear run-on assay was performed to explore the mechanisms of this regulation. These studies indicate that T3 induction of skeletal muscle acylphosphatase mRNA is due, at least in part, to a fast and transient increase in the rate of gene transcription, within 4 h after hormone administration. A very rapid decrease is then observed within a further 2 h. T3-dependent accumulation of the mRNA for the skeletal muscle acylphosphatase requires ongoing protein synthesis, as confirmed by inhibition with cycloheximide or puromycin. These findings indicate that the transcriptional regulation of the gene may be indirect.

Acid Anhydride Hydrolases

Enhanced expression of myogenic regulatory genes in aging skeletal muscle.

MyoD, myogenin, myf-5, and MRF4, belonging to the family of basic helix-loop-helix (bHLH) myogenic regulatory factors (MRFs), control muscle cell differentiation, in concert with other transcription factors such as MEF-2, yet their role in age-related skeletal muscle alteration has not been addressed. We here report that MyoD and myogenin transcripts are expressed at high levels in the hind limb muscles of newborn mice and their level of expression continuously declines throughout postnatal life to become virtually undetectable in the adult mouse. However, these transcripts are again expressed at high levels in the muscles of older mice. MRF4 transcript, on the other hand, is present at a constant level throughout the life span of the animal. Conversely, the expressions of myf-5 and MEF-2C, components of the autoregulatory loop for the activation of bHLH gene expression, conspicuously increase in adult and senile muscle. In order to establish whether these transcripts are functioning in the aged muscle we investigated the expression of bHLH inhibitory factor Id mRNA showing that it does not present significant changes during aging. Immunofluorescence analysis with an anti-myogenin antibody revealed nuclear accumulation of the protein in the muscle fibers of old, but not of adult, mice. Muscle-specific genes transactivated by MyoD and myogenin such as AChR, MLC, and MCK are also up-regulated during aging, albeit at a lower level. Significant changes in the size and ratio of type I/type II fibers are detectable in senile muscle. These findings show that all members of the MRF family are expressed to a high extent and are likely active in senile muscle. It is conceivable that these changes might operate as a compensatory mechanism in maintaining the expression of differentiated muscle products in senile muscle at a steady-state level.

Aging

Expression of growth arrest-specific (gas) genes in senescent murine cells.

The growth arrest-specific (gas) genes were initially identified on the basis of their preferential expression in mouse fibroblasts during quiescence, followed by down-regulation upon reentry into the cell cycle. We here report studies on the expression of these genes in murine fibroblasts undergoing replicative senescence in vitro. Our results indicate a different behavior between senescent and GO-arrested quiescent fibroblasts. Expression of the gas1 and 6 genes was dramatically reduced in senescent cells. Only basal levels of gas2, 3, and 5 genes were detected in senescent fibroblasts, and they were independent of the growing conditions of the cultures. Down-regulation of the gas1 gene expression in senescent cells was apparently due to reduced transcription of the gas1 gene. This correlates with an altered pattern of factors that bind to the promoter region of the gas1 gene, as measured by band shift assay with nuclear extracts of senescent fibroblasts.

Animals

Early detection of cell metabolism with a silicon microsensor.

A silicon microsensor (ISFET--Ion Sensitive Field Effect Transistor) has been used to detect the metabolism of a cell population cultured on a coverslip and positioned close to the sensor surface. The system output is analyzed as a function of cell density.

Animals

Regulation and expression of a growth arrest-specific gene (gas5) during growth, differentiation, and development.

The growth arrest-specific gas5 gene was isolated from mouse genomic DNA and structurally characterized. The transcriptional unit is divided into 12 exons that span around 7 kb. An alternative splicing mechanism gives rise to two mature mRNAs which contain either 11 or 12 exons, and both are found in the cytoplasm of growth-arrested cells. In vivo, the gas5 gene is ubiquitously expressed in mouse tissues during development and adult life. In Friend leukemia and NIH 3T3 cells, the levels of gas5 gene mRNA were high in saturation density-arrested cells and almost undetectable in actively growing cells. Run-on experiments indicated that the gas5 gene is transcribed at the same level in both growing and arrested cells. On the other hand, in dimethyl sulfoxide-induced differentiating cells a sharp decrease in the rate of transcription was observed shortly before the cells reached the postmitotic stage. These results indicate that in density-arrested cells accumulation of gas5 mRNA is controlled at the posttranscriptional level while in differentiating cells expression is regulated transcriptionally.

3T3 Cells

Anti-hepatitis C virus epidemiological study in two dialysis centers in Florence.

We studied the prevalence and incidence of anti-hepatitis C virus (HCV) antibodies in 350 patients during 15 months and looked for some risk factors. We found a significant correlation between anti-HCV positivity and length of dialysis treatment and treatment in more than one center. We propose some prophylactic rules.

Ambulatory Care Facilities

Regulation of expression of growth arrest-specific genes in mouse fibroblasts.

The suppression of growth arrest-specific (gas) gene expression by serum appeared to be independent of protein synthesis, but expression in resting cells was sensitive to 2-aminopurine, an inhibitor of intracellular protein kinases. Although accumulation of gas gene mRNA was reduced by serum, nuclear transcription of the gas-2, -3, and -5 genes was observed in serum-stimulated cells, indicating that posttranscriptional events may regulate mRNA levels. Growth induction by serum, on the other hand, led to suppression of transcription of the gas-1 gene. Cell cycle regulation and the serum response of gas-1 were lost in ras-transformed cells.

Animals

Spontaneous channel activity induced by tumor promoter TPA in chick myotubes.

Patch-clamp recordings were used to study the activation of ion channels in the cell membrane of cultured embryonic chick myotubes treated with the specific activator of protein kinase C, the phorbol ester 12-O-tetradecanoyl-phorbol-13-acetate (TPA; 1 x 10(-7) M). Myotubes exhibited a spontaneous channel activity when the TPA-induced dedifferentiative processes developed. This consisted in the activation of inward current channels (approximately 35 pS conductance; approximately 6 ms open time). These spontaneously active channels were insensitive to alpha-bungarotoxin, curare, atropine and tetrodotoxin and were not inhibited by the withdrawal of TPA. It is suggested that a prolonged stimulation of the protein kinase C causes a irreversible deregulation of the membrane channel function during cell dedifferentiation.

Animals

Traumatic dislocation and fracture dislocation of the hip. A long-term follow-up study.

Of 84 fracture dislocations of the hip reviewed, 73 were posterior fracture dislocations, nine were central, and two were obturator. Fifty-five were followed from one to 30 years (average, 4 1/2 years). The patients' ages ranged from three to 83 years (average, 33.1 years). All had primary attempt at closed reduction, with 15 treated with subsequent open reduction (six immediate and nine delayed). Satisfactory results were obtained in 42% of hips treated with closed reduction and 40% of those treated with open reduction. Statistical analysis of the results was done. A stable closed reduction produced results as satisfactory as open reduction. When followed for a sufficiently long time interval, severe fracture dislocations, regardless of treatment mode, caused unsatisfactory results.

Femur Head Necrosis

Biofiltration in elderly uremic patients.

We treated five elderly patients with conventional hemodialysis (CH) or biofiltration (BF) to establish whether their dialytic tolerance was better. For three patients treatment time was reduced from twelve to nine hours a week; for the other two, treatment time remained unchanged (10.5-12 h/week) because of their high interdialytic weight gain. At the beginning and end of the study, clinical status, biochemical data, nutritional status and acid-base balance (ABB) were checked. Plasma levels of small molecules, potassium and phosphate were unchanged for all patients. All had a lower number of episodes or less severe hypotension and good control of ABB. No patients had metabolic alkalosis or worsened nutritional status. For all patients BF was an efficacious choice compared to CH, giving them good health.

Acid-Base Equilibrium

Reversible cerebral ischemias: a comparative analysis of risk factors in TIAs and in RINDs.

A retrospective study in which 709 patients, 522 with RIND and 187 with TIA, were compared in respect of common risk factors (RFs) for acute cerebrovascular disease. The two forms of the disease differed significantly in respect of smoking, hematocrit, hypercholesteremia, hypertriglyceridemia and hyperuricacidemia. Although these RFs do not seem to be determinants of or discriminants between the two forms of acute cerebrovascular disease, it is nonetheless highly probable that, together with all the other RFs, they have a facilitatory role.

Atrial Fibrillation

Effect of chronic propranolol treatment on bone changes of secondary hyperparathyroidism in dialysis patients.

To assess the effect of long-term propranolol therapy on uremic osteodystrophy, we evaluated retrospectively the biochemical, X-ray, and bone histological changes in 9 dialysed hypertensives who had been on propranolol treatment for periods ranging from 1 to 8 years. The control group included 9 well-matched dialysed uremics never treated with beta-blockers. The two groups did not differ in serum ionized calcium or iPTH levels. The incidence of bone resorption evaluated on X-ray findings and on bone biopsy specimens was of a comparable degree in the two groups. Our data show that propranolol even if started early in the course of renal failure, is of no benefit in preventing uremic bone disease.

Bone Resorption

Bone changes in end-stage oxalosis.

Primary hyperoxaluria is a rare metabolic disease characterized by exaggerated production of oxalic acid. Clinically the disease is characterized by recurrent calcium nephrolithiasis, progressive renal failure, and early death in uremia. As the regular dialysis treatment may prolong survival, a new syndrome may develop. This is due to intense and continuous deposition of calcium oxalate crystals in soft and bone tissues. The radiologic aspects of oxalate deposition in four adult patients on chronic renal dialysis with histologic and clinical evidence of massive bone oxalosis are reported.

Adolescent

Total antioxidant capacity (TAC): is it an effective method to evaluate the oxidative stress in uraemia?

Lipoprotein abnormalities are common in uraemia and are considered important factors for development of atherosclerosis and progression of renal disease. Reduction of total antioxidant capacity (TAC) and lipid peroxidation (LP) probably play a major role in both processes. The aim of this study was to assess the effect of renal function, dietary manipulation and lipids on TAC of uraemic patients with different chronic renal failure (CRF). Sixty patients (36M, 24F), aged 60 +/- 12 years were divided into five groups according to serum creatinine levels (sCr,mg/dl)--CRFI, 1.5-3; CRFII, > 3-5.5; CRFIII, > 5.5; CRFIV, > 3 on vegetarian supplemented diet (SD); CRFV haemodialysis patients (HD)- and investigated for TAC by enhanced chemiluminescent assay, autoantibodies against oxidized LDL (oxLDLAb), lipids, apolipoprotein AI, B, Lp(a) and uric acid (UA). The results were compared to a control group of 19 people (8M, 11F), aged 52 +/- 11 years with sCr < 1.5. TAC increased significantly with the progression of CRF and was strongly related to both sCr and UA. Lipids and SD did not show any influence on TAC. Unexpectedly, lipid peroxidation did not correlate to TAC, neither to sCr or UA. HD accounted for a mild reduction of both TAC and LP. Patients on SD showed a marked reduction of LP as compared to patients with a similar degree of renal failure (CRF-III) but on conventional diet. Our results suggest that elevated TAC in uraemia is likely to be dependent on increased UA levels and does not seem to induce an effective protection in vivo from oxidative stress. In conclusion, TAC does not appear to be a reliable method for assessing the oxidative susceptibility of CRF patients.

Adult