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Biomedical subjects

F Locatelli

Publications and source records attributed to F Locatelli.

At least 487 records · Page 27Linked to original sources
PubMedDate not supplied

[Water quality cuts down the chronic inflammatory risk: how to obtain it and keep it over time].

BACKGROUND: Every week, approximately 400 liters of water used for dialysate production come into direct contact, through the semi-permeable membrane of the dialyzer, with the dialysis patient's blood stream. Therefore, submitting municipal water to an adequate depuration process before its use for dialysis becomes necessary. METHODS: Problems related to the implementation, updating and management of a dialysis water treatment system are analyzed. The results of the most recent multicenter studies on dialysis fluids quality are also reviewed. RESULTS: The best approach to plan, implement and manage a dialysis water treatment system, first, consists of defining the standards of chemical and microbiological water quality. The most diffused and commonly accepted standards are those recommended by the Association for Advancement of Medical Instrumentation (AAMI) and the European Pharmacopea (EP), which allow a maximum bacterial growth of, respectively, 200 CFU/ml and 100 CFU/mL and a maximum endotoxin concentration of 2 IU/mL and 0.25 IU/mL. A modern dialysis water treatment system provides a final purification process, mainly by reverse osmosis (RO), together with different pre-treatment levels and a hydraulic distribution circuit. Therefore, as RO produces water of optimal chemical and microbial quality, all efforts in the dialysis unit must be aimed at keeping this quality as constant as possible over time, by carrying out effective maintenance strategies and system disinfection. Nevertheless, several multicenter studies reported that 7-35% of water samples exceed a bacterial growth of 200 CFU/mL and that 44% of them display endotoxin concentrations >5 IU/mL. CONCLUSIONS: The results of multicenter studies indicate that the microbial quality of dialysis fluids is, unfortunately, still an often neglected problem. Evidence of a possible relationship between dialysis fluid contamination and patient morbidity, as well as the availability of systems and machines allowing purity levels that were unimaginable only a few years ago, must be a stimulus for modifying clinical practices and starting the improvement processes aimed at maximally reducing the risk of microbial contamination in the dialysis water, as already done with chemical contamination.

Chronic Disease↗
PubMedDate not supplied

[Use of dialysate conductivity to obtain neutral sodium balance in chronic hemodialysis patients].

In order to assure a zero sodium balance in hemodialysis patients, attaining 'constant' values of total body water and plasma water sodium concentration at the end of each dialysis session is a basic pre-requisite. This is achieved by matching the ultrafiltration to the inter-dialytic weight gain and by individualizing dialysate sodium concentration at each dialysis session by making use of a kinetic model. Clinical results suggest that the single pool variable volume sodium kinetic model allows the targeted end-dialysis plasma water sodium concentration to be obtained. Nevertheless, this model is not suitable for routine clinical application, because of difficulties in the real-time determination of initial plasma water sodium concentration and 'effective' sodium dialysance. Measuring dialysate conductivity at the inlet and outlet ports of the dialyzer allows the estimation of sodium transfer during dialysis, if the function of concentration versus conductivity is known. If sodium transfer is measured at two different inlet dialysate conductivities, it is possible to determine ionic dialysance and systemic plasma water conductivity, which can be used routinely to apply the single pool sodium kinetic model. Given that ionic dialysance and plasma water conductivity can be measured easily repeatedly and inexpensively at each dialysis session without the need for blood sampling or laboratory determinations, it can be expected that conductivity kinetic models will soon become a part of everyday clinical practice.

Electric Conductivity↗
PubMedDate not supplied

[The Dialysis Outcomes and Practice Patterns Study (DOPPS): results of the Italian cohort].

BACKGROUND: The Dialysis Outcomes and Practice Patterns Study (DOPPS) is an international prospective, longitudinal, observational study examining the relationship between dialysis unit practices and outcomes for hemodialysis (HD) patients in seven developed countries France, Germany, Italy, Spain, United Kingdom, Japan and the United States. Results of the DOPPS in Italy are the subject of this report. METHODS: A national representative sample of 20 dialysis units (21 in Germany) was randomly selected in each of the European DOPPS countries (Euro-DOPPS). In these units, the HD in-center patients were included on a facility census, and their survival rates continuously monitored. A representative sample of incident (269 in Italy, 1553 in the Euro-DOPPS) and prevalent (600 in Italy, 3038 in the Euro-DOPPS) patients was randomly selected from the census for more detailed longitudinal investigation with regard to medical history, laboratory values and hospital admission. RESULTS: Comparing the Italian and Euro-DOPPS cohorts we found comparable mean age for prevalent patients (61.4 vs. 59.5 yrs), but incident patients were older in Italy. Italian prevalent patients had less cardiovascular disease, more satisfactory nutritional status and more frequent use of native vascular access. These data were associated with a comparable mortality (15.7 vs. 16.3 deaths/100 patient yrs), but morbidity was lower in Italy. Kt/V levels were comparable in the two cohorts (1.32 vs. 1.37), but 35% of Italian patients showed a Kt/V below the recommended target. Moreover, hemoglobin levels were below 11 g/dL in 60% of Italian patients. CONCLUSIONS: The DOPPS results bring to light several positive aspects and the opportunity for further possible improvements for Italian patients, but at the same time highlight some critical points that could represent a risk for dialysis quality.

Aged↗
PubMedDate not supplied

[Maintenance and monitoring of water treatment system].

Water treatment systems must be submitted to maintenance, disinfections and monitoring periodically. The aim of this review is to analyze how these processes must complement each other in order to preserve the efficiency of the system and optimize the dialysis fluid quality. The correct working of the preparatory process (pre-treatment) and the final phase of depuration (reverse osmosis) of the system need a periodic preventive maintenance and the regular substitution of worn or exhausted components (i.e. the salt of softeners' brine tank, cartridge filters, activated carbon of carbon tanks) by a competent and trained staff. The membranes of reverse osmosis and the water distribution system, including dialysis machine connections, should be submitted to dis-infections at least monthly. For this purpose it is possible to use chemical and physical agents according to manufacturer' recommendations. Each dialysis unit should predispose a monitoring program designed to check the effectiveness of technical working, maintenance and disinfections and the achievement of chemical and microbiological standards taken as a reference. Generally, the correct composition of purified water is monitored by continuous measuring of conductivity, controlling bacteriological cultures and endotoxin levels (monthly) and checking water contaminants (every 6-12 months). During pre-treatment, water hardness (after softeners) and total chlorine (after chlorine tank) should be checked periodically. Recently the Italian Society of Nephrology has developed clinical guidelines for water and dialysis solutions aimed at suggesting rational procedures for production and monitoring of dialysis fluids. It is hopeful that the application of these guidelines will lead to a positive cultural change and to an improvement in dialysis fluid quality.

Disinfection↗
PubMedDate not supplied

Recombinant human granulocyte-macrophage colony stimulating factor (rHuGM-CSF) in cyclic neutropenia.

We describe the case of a 12-year-old boy affected by cyclic neutropenia, at high risk of developing life-threatening infections, treated with recombinant human granulocyte-macrophage colony stimulating factor (rHuGM-CSF). The drug was effective in reducing the severity of neutropenia and infectious complications in our patient. It was administered for brief periods of time, in contrast to the daily continuous administration reported for rHuG-CSF. Therefore, more extensive studies must be performed to identify the most effective time schedule for the drug. In vitro studies of hemopoietic progenitor cells were useful, in this case, to predict treatment response.

Child↗
PubMedDate not supplied

Use of peripheral blood stem cells to accelerate hemopoietic recovery following autologous bone marrow transplantation.

Twenty-one patients with high risk non-Hodgkin's lymphoma (NHL) or Hodgkin's disease (HD) underwent autologous bone marrow transplantation (ABMT). Nine out of 21 patients received in addition to bone marrow (BM) cells also peripheral blood (PB) cells collected by leucapheresis performed in the recovery phase after high-doses of either cyclophosphamide or etoposide (7 patients), or after ara-C (2 patient). All patients receiving BM + PB cells had ABMT as salvage therapy following extensive relapse or progression of their disease. The addition of PB cells to BM cells allowed a significantly faster recovery after ABMT. Median time to reach WBC greater than 1,000/microL was 14 days versus 20.5 days for patients receiving BM only. Furthermore, a reduced requirement of supportive care and a shorter period of isolation was observed. These results confirm that PB cells combined with BM cells allow a prompt hematopoietic reconstitution after myeloablation. In addition, the data demonstrate the efficacy of PB cells collected after various cytotoxic drugs, even in patients previously exposed to cytoreductive regimens.

Adolescent↗
PubMedDate not supplied

[Immunosuppressive role of radiotherapy in bone marrow transplant in patients with aplastic anemia].

From April 1976 through August 1989, 66 patients with aplastic anemia were treated on either of two immunosuppressive regimens in preparation for allogeneic bone marrow transplantation (BMT) from matched donor. Seventeen patients were treated with cyclophosphamide (50 mg/kg for 3 days) followed by thoracoabdominal irradiation (TAI), 6 Gy/1 fr and 2 patients, receiving marrow graft from partially matched family donors, were treated with cyclophosphamide (50 mg/kg for 3 days), TAI (6 Gy/1 fr) and Ara-C (4 g/mq for 2 days). Forty-seven more patients were treated with cyclophosphamide alone (50 mg/kg for 4 days). All patients received prophylactic treatment with methotrexate (15) or cyclosporine A (51) to avoid graft-versus-host disease. Mean time to engraftment was 12 days after chemotherapy and TAI and 15 days after cyclophosphamide (Cy) alone. No marrow rejections were observed in the TAI group: the two infants that received partially matched marrow allografted and are alive and well. Two patients treated with cyclophosphamide alone rejected allogeneic marrow. Long-term overall survivals are similar: 64% for TAI + Cy group and 56% for Cy alone group. In spite of the immunosuppressive regimen employed, young patients (under 20 years) do better than older ones (survival: 65% vs 45%, respectively). Thus, patient's age seems to be the main factor determining overall survival after allogeneic BMT. We conclude that the use of irradiation does not add significantly to the survival of aplastic patients; given the possible toxic long-term effects of irradiation, it would probably be wise to restrict the combined use of cyclophosphamide and irradiation to the patients sensitized to their donors, to those receiving partially matched marrow from family donors or in programs involving T-cell depletion.

Adolescent↗
PubMedDate not supplied

[Graft vs host disease in a child undergoing allogeneic bone marrow transplantation].

GVHD has a major role in the morbidity after a BMT, even if the donors are HLA matched siblings. The risks of a severe GVHD increase when using partially matched family donors or matched unrelated donors. An acute GVHD occurs within 100 days from BMT, whereas a chronic GVHD occurs in the first year. Both acute and chronic GVHD are less frequent and severe in children. The experience of the transplant team of Pavia is in agreement with this statement. The incidence of GVHD was extremely low even then compared with the data of the Italian pediatric BMT group. In transplant performed with HLA matched donors the incidences of severe acute and chronic GVHD were 5 and 8%.

Acute Disease↗
PubMedDate not supplied

[Bone marrow transplantation in the treatment of severe aplastic anemia].

Bone marrow transplantation (BMT) in patient affected by severe aplastic anemia (SAA), is successful in 70-80% of cases, when performed with HLA identical brother or syngeneic twin as donors, and in 11-45% of cases when performed from aploidentical-identical related or HLA identical unrelated donor. The different conditioning regimens (Cy alone or in combination with TBI) have shown similar results in the long term outcomes. Cyclosporin-A is very effective in avoiding rejection and controlling GVHD.

Anemia, Aplastic↗
PubMedDate not supplied

Successful lectin-separated bone marrow transplantation in adenosine deaminase deficiency-related severe immunodeficiency.

Severe combined immunodeficiency disease (SCID) with adenosine deaminase (ADA) deficiency is a genetic autosomic recessive disorder with profound impairment of T-cell function, invariably complicated by fatal infections. The absence of ADA-enzyme and the accumulation of deoxy-ATP, with toxic effects on the T-lymphocytes is the common feature of this disease. As a consequence, lymphoid precursors failure to develop into mature T-cells, resulting in absolute lymphopenia and atrophy of the thymus. Bone marrow transplantation from an HLA-identical donor is considered the treatment of choice for this disease. We describe the case of a 1-month-old child with ADA deficiency SCID who underwent bone marrow transplantation (BMT) using paternal haploidentical, lectin-separated marrow, as a source of hemopoietic stem cells.

Adenosine Deaminase↗