Biomedical subjects
A Ramello
Publications and source records attributed to A Ramello.
Use of amino acids in peritoneal dialysis solutions.
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Idiopathic calcium nephrolithiasis.
Calcium nephrolithiasis (CaNL) accounts for more than 70% of all renal stones, and its prevalence has increased in the last decades. Under this definition are included patients passing stones, composed of calcium oxalates and/or calcium phosphates. Current views of the pathogenesis of CaNL are based on the role of metabolic abnormalities which concur to render urines more conducive to crystallization. Therefore, the diagnostic approach is aimed at detecting these abnormalities, and the medical treatment assumes that a decrease in the risk of lithogenesis will result in remission or improvement of recurrences. The workup of the patients with CaNL begins with the analysis of passed stones and X-ray, sonography or other imaging techniques. Eligible patients, that is, both recurrent active stone formers and single-stone formers with individual risk factors, are considered for a metabolic evaluation, by which a number of blood and urine parameters are measured and others calculated. These include estimates of urine state of saturation with calcium and uric acid salts, net gastrointestinal alkali absorption, renal threshold of phosphate and other renal clearances and net acid and total nitrogen excretions. Basically, this screening is informative on renal function, metabolic abnormalities and their pathophysiology, risk of stone formation and dietary habits. During treatment it gives information about patient compliance and adverse effects of therapy. The cost of a comprehensive screening in Piedmont is 192,000 ITL (100 Euro) and rises to 300,000 ITL (154 Euro) if hormones and hydroxyproline are measured. In individual patients second- and third-level studies are performed, in order to detect systemic diseases which account for about 20% of CaNL in our series. Cost-to-benefit analysis has shown that the medical procedures for CaNL yield considerable saving in terms of difference between expenditure for drugs and testing and reduction of stone events. However, the current workup cannot be considered exhaustive, because misleading events may hamper the relation between laboratory findings and clinical outcome, and factors other than urine composition have appeared on the scenario of nephrolithiasis. These represent our challenge for the third millennium.
[Clinical and metabolic features of renal calculi in adults in regard to age of onset].
BACKGROUND: In this paper, the clinical and metabolic patterns of nephrolithiasis in different ages of adulthood are studied. METHODS: Eight-hundred patients observed at the Mauriziano Hospital between 1990 and 1995, were classified into 3 groups, on the basis of age at the onset of disease: A: 20 through 39 years; B: 40 through 59; C: 60 years and over. RESULTS: Calcium-oxalate stones had a lower recurrence in C (19.1%) and B (31.5%) than in A (41.7%). Pure uric acid stones recurred in 18.9% of C, 16.7% of B and 4.3% of A. The prevalence of hypercalciuria was higher in A (50.3%) than in B (35.9%) and C (36%); so did hypocitraturia. Hyperuricuria was lower in A (5%, p < 0.05) than in B (9.4%) and C (10%). Low urine pH (< 5.5) was 13% in A, 21.3% in B, 38% in C. Prevalence of hyperoxaluria was about 14% in all groups. The whole prevalence of secondary forms of stone disease was 13% in A, 12% in B and 30% in C. Differences among groups were mainly due to prevalence of urological abnormalities and urinary tract infection. In patients without metabolic disturbances. urological abnormalities or urinary tract infections altogether, were 4.6% in A; 5.2% in B; 33% in C. Urological approach removed 8% of stones in A, 5.6% in B and 10.2% in C. CONCLUSIONS: Higher morbidity in younger patients could be due to a lower prevalence of easier-passing uric acid stones. The higher occurrence of urological disturbances and struvite stones in the elderly could explain the higher morbidity in this group.
[Maintenance of the tunnel and skin exit site of peritoneal catheters. Current situation and orientation of the dialysis centers of the Piedmont and the Valle d'Aosta].
A questionnaire was sent to the 23 Dialysis Centers of the Piedmont and Aosta Valley Regions to probe present trend on the choice of peritoneal catheter, its setting, the tunnel conformation, the first use and its maintenance. The nephrologists attach great importance to a well fixed subcutaneous tract of the catheter: this goal is obtained with wide use of pre-molded catheters, often with long and curvilinear tunnel. Avoiding an early use of the catheter and the choice of small volumes in the first weeks will permit an efficient stability of the cuff and the reduction of the risk of leakage. The choice in maintenance and monitoring of the exit-site are various and it often has a protection covering; clinical controls are made on a monthly basis.
The costs of dialysis in Italy.
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[Diabetes mellitus is currently one of the most frequent causes or associated causes of uremia. Data from the Piedmont registry of dialysis and transplantation (update, December 1993)].
A regular dialytic treatment of diabetic patients is until accepted from about twenty years in many areas. Aim of this work was a retrospective analysis of main clinical and survival data of diabetic patients (diabetic nephropathy or diabetes as comorbidous factor = 659 cases) admitted for dialysis in Piedmont (Northern Italy Region about 4,400,000 inhabitants) in the period 1981-1993 (functional recovery and follow-up < 1 month excluded). A progressive increment in incidence of diabetic patients was seen mostly in the aged. At 12/31/1993, 263 of 2404 patients admitted for dialysis were diabetics (10.9%); the majority of them was treated in Hospital Centers with bicarbonate haemodialysis (54.4%), while a small group was treated with CAPD (12.9%). During the years ¿80 was seen a progressive leaving of CAPD as first choice method in this population and in the last period the orienteering is the utilization of mixed methods (diffusive-convective as first choice). As regards the survival are not prominent significant differences between this cohort and the cohort affected by vasculopathy as comorbidous factor (86.2 and 54.2% in diabetics vs 78.6 and 55.2% in patients affected by vasculopathy at 1 and 3 years--p = 0.3481; patients aged 45-64 years). In conclusion the cohort of diabetic patients represent a good marker of the clinical problems of the elder population with high clinic risk, in progressive increasing in our Region.
[Urinary tract infection prevention in catheterized patients. Prevalence National Study: preliminary studies at the Pinerolo Hospital].
Urinary tract infection incidence can be a possible indicator of the quality of health care in hospital. It is now clear that some kind of health care, practice and particular organizational and structural orders change the risk of UTI during hospitalizations. One third of hospital infections can be prevented by carrying out specified rules and guidelines. About 80% of UTI are a consequence of bladder catheterism. According to Major Health Institute, our Hospital takes part in a Study Group on the incidence and prevention of UTI related to bladder catheterism. Preliminary results show how much surgery activity still weighs in the cases of necessity of catheterism. Differently, urinary retention and incontinence and diuresis monitoring have a minor incidence. However the incidence of UTI after bladder catheterism is very high in our study (until 85%) also and hence the subsequent necessary antimicrobical therapy.
Regional registry of dialysis and transplantation of Piedmont, Italy (RPDT). Thirteen years of experience. Regional Registry of Dialysis and Transplantation.
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Dialysis-related amyloidosis in a large CAPD population.
We studied 212 patients from 13 Italian dialysis centers to evaluate the clinical aspects of dialysis-related amyloidosis in continuous ambulatory peritoneal dialysis (CAPD). The mean age was 64.2 +/- 12.3 years and mean time on dialysis was 36.9 +/- 25.1 months. Residual diuresis was 615.7 +/- 554.0 mL/day and plasma beta 2-microglobulin (beta 2M) level was 27.0 +/- 12.8 mg/L. Radiological skeletal examination, neurological problems related to beta 2M, and urinary and dialytic balance of beta 2M were evaluated. Correlations between age, time on dialysis, residual diuresis, beta 2M plasma levels, beta 2M peritoneal and renal removal, carpal tunnel syndrome, and bone disease were studied. Only the number of bone lesions had a significant positive correlation with patient age and negative correlation with residual diuresis. The latter had an inverse relation with beta 2M plasma levels. Dialytic age did not correlate with any of the parameters. No other correlation was observed. Hand lesions were found in 85% of patients with bone dialysis-related amyloidosis. In conclusion, residual diuresis in our patients played a positive role in the number of bone localizations. Only age, but not time on dialysis, had a positive impact on the bone lesions. The high percentage of hand lesions suggests that the observation of this skeletal segment is a simple, safe, and effective modality of bone follow-up for dialysis-related amyloidosis.
Treatment of anaemia in CAPD patients with recombinant human erythropoietin.
EPO is an effective therapy of anaemia in CAPD patients. Monitoring serum iron level during EPO therapy is essential. Hypertension is frequently seen in patients with EPO therapy.
Ca++ and 1,25(OH)2D3 regulate in vitro and in vivo the response to human recombinant erythropoietin in CAPD patients.
In vitro studies indicate that the culture medium Ca++ concentration conditions the response to erythropoietin of bone marrow erythropoietic cells which also have specific receptors for 1,25(OH)2D3. We therefore evaluated in 12 anemic CAPD patients: 1) in vitro with increasing concentrations of Ca++ alone or Ca++ plus 1,25(OH)2D3 a) Ca++ in the bone marrow erythroid cell cytoplasm; b) colony (BFU-E and CFU-E) growth from bone marrow erythroid cells. 2) in vivo before and after 24 weeks of i.v. recombinant human erythropoietin (rHuEPO) therapy a) bone marrow erythroid cell cytoplasmic Ca++; b) BFU-E and CFU-E growth. Results showed that in CAPD patients, in vitro cytoplasmic Ca++ in bone marrow erythroid cells, and BFU-E and CFU-E growth were lower than in normals and the addition of Ca++ caused a dose-dependent increase; 1,25(OH)2D3) potentiated these effects; 2, in vivo rHuEPO therapy normalized the aforementioned parameters. An inverse relationship was seen between the bone marrow erythorid cell cytoplasmic Ca++ levels before therapy and the duration of therapy necessary to correct anemia. These data underline the role of Ca++ and 1,25(OH)2D3 in erythropoiesis in uremic patients and may aid the understanding of the mode of action and the degree of response to rHuEPO in CAPD patients.
Bone marrow erythroid precursor Ca++ regulates the response to human recombinant erythropoietin (rHuEPO) in hemodialysis patients.
The modulation of erythropoiesis by erythropoietin is conditioned by the concentration of Ca++ in the cytoplasm of the bone marrow erythroid precursors. We evaluated in vitro erythroid colony development from bone marrow erythroid precursors incubated with increasing concentrations of Ca++ or Ca++ plus 1,25 (OH)2 D3, and bone marrow erythroid precursor cytoplasmic Ca++ concentrations in 10 anemic hemodialysis (HD) patients before and during rHuEPO therapy. Results showed that: a) in vitro: in uremics patients before rHuEPO therapy, bone marrow erythroid precursor cytoplasmic Ca++ was lower than in normal subjects; the addition of Ca++ to the bone marrow erythroid precursors induced a dose-dependent Ca++ and erythroid colony development increase; 1,25 (OH)2 D3 potentiated this effect; b) in vivo: rHuEPO normalized bone marrow erythroid precursor Ca++ and erythroid colony development. An inverse correlation was seen between bone marrow erythroid colony development, precursor CA++ before therapy, the in vitro erythroid and the rHuEPO dose needed in vivo to normalize hematological parameters. These data emphasize the role of Ca++ in erythropoiesis and may aid understanding of the mode of action of rHuEPO in HD.
A human leukemic T cell line (PF-382) inhibits the growth of myeloid and erythroid progenitor cells.
We have recently described a human T cell line, named PF-382, obtained from the pleural effusion of a child with T-acute lymphoblastic leukemia (T-ALL), which expresses phenotypic and functional features of suppression. In this study we report that PF-382 spontaneously releases a factor which inhibits the in vitro growth of myeloid (CFU-GM) and erythroid (BFU-E) progenitor cells. The same effect is obtained when irradiated PF-382 cells are co-cultured with the hemopoietic precursors. In both instances, maximal inhibitory activity is exerted on day 14 CFU-GM and BFU-E obtained from the light density nonadherent fraction of normal human bone marrow and peripheral blood; this finding suggests that the target of the inhibition is represented by the more immature elements within the progenitor cell compartment. Progressive depletion of monocytes, T, B lymphocytes, and NK cells as well as recloning experiments indicate that the inhibitory effect is directly exerted on the target cell and not via an intermediate population of accessory cells. Partial purification by gel filtration and by subsequent high performance liquid chromatography demonstrates that this factor is a protein with a molecular weight of 47 kd. The physicochemical characterization and the specific functional properties suggest that the PF-382 inhibitory factor represents a lymphokine which differs from those so far reported. The PF-382 cell line provides a useful model toward a better understanding of the interrelations between T cell subsets and other hemopoietic compartments.
[Evaluation of a new method for serological diagnosis of infectious mononucleosis].
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[On porphyrin metabolism in drepanocytic heterozygosis].
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[Therapy of primary siderochromatosis and siderosis: experimental and clinical study].
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[Effect of aging on erythrocyte lysates. I. Electrophoretic study].
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