PubMed Health⌕ Search

Biomedical subjects

M Milan

Publications and source records attributed to M Milan.

At least 55 records · Page 3Linked to original sources
PubMed1990

Limb reduction defects in Emilia Romagna, Italy: epidemiological and genetic study in 173,109 consecutive births.

Epidemiological and genetic variables in limb reduction defects (LRD) were analysed during the years 1978 to 1987 in a case control study in Emilia Romagna, northern Italy. During the observation period, 83 neonates out of 173,109 consecutive births had LRD (4.8 per 10,000). Cases were divided into five subgroups: transverse, intercalary, longitudinal, split, and multiple types of LRD. Of all cases, 64% were upper limb, 21% lower limb, and 15% both. Coexisting non-limb malformations were found in 10 cases (12%), five with recognised syndromes and five with other associated defects. About 7.2% of first degree relatives had defects involving the skeletal system. In two cases the mother had the same type of LRD (a split). No recurrence among sibs was observed. Risk factors correlated with LRD were found to be low birth weight (2500 g or less), vaginal bleeding, and threatened abortion.

Consanguinity↗
PubMed1990

Paired filtration dialysis: studies on efficiency, flow dynamics and hydraulic properties of the system.

Several strategies have been proposed to increase dialysis efficiency in order to reduce dialysis treatment time. Paired filtration dialysis (two-chamber technique) is a new technique combining the advantages of highly permeable membranes and convective transport with the high depurative efficacy of diffusion. The system operates with two units in series (hemofilter + dialyzer) with membranes of polysulfone and hemophan, respectively. A detailed analysis of the hydraulic properties of the system and its possible optimization in terms of depurative efficiency is reported in this paper. In vitro and in vivo tests provided data sufficient to draw some hypotheses on a new utilization of the system. The system appears to be adequate for operating under conditions of high blood flows, however, some limitations were evidenced during our evaluation: the convective component may be insufficient and further increases are impossible because of the limiting effect of the low surface area of the hemofilter; the configuration in which the weight loss is achieved in the hemofilter exposes to the risk of backfiltration in the dialyzer, reducing the benefits of a highly biocompatible system, and the use of acetate in the dialysate and/or lactate in the substitution fluid may interfere with a satisfactory correction of metabolic acidosis. On the basis of our evaluations, some changes can be proposed such as: (1) increased surface area of the hemofilter; (2) use of blood flows higher than 300 ml/min; (3) use of bicarbonate in the dialysate and in the replacement solution; (4) increased convective component with ultrafiltration rates of 50-60 ml/min and full replacement with substitution fluid in between the two filters, and (5) weight loss achieved in the dialyzer with a constantly positive transmembrane pressure. With such a modification of the operative conditions, paired filtration dialysis can be probably applied as a highly efficient dialysis technique in a large number of patients with a significant reduction of dialysis treatment time.

Blood Flow Velocity↗
PubMed1990

Pathophysiology of ultrafiltration in peritoneal dialysis.

Pathophysiology of peritoneal ultrafiltration is analyzed in the present study. Peritoneal equilibration test is the easiest procedure to study in detail the possible causes of failure to control the ultrafiltration rate in patients undergoing peritoneal dialysis. Membrane failure, reduction in peritoneal blood flow, excessive lymphatic reabsorption catheter malposition, and fluid sequestration are the most common causes of ultrafiltration loss. Pharmacologic manipulation of peritoneal membrane, correction of mechanical inconvenients, reduction in peritonitis rate and in the level of immunostimulation of the mesothelial macrophages, together with a careful policy in terms of glucose concentration in the dialysate and dwell times may contribute not only to treat different forms of ultrafiltration loss but also to prevent their incidence.

Algorithms↗
PubMed1989

Acid base correction in bicarbonate CAPD patients.

Bicarbonate has been proposed as buffer in CAPD solutions in recent years instead of lactate and acetate. The present study is designed to evaluate peritoneal bicarbonate kinetics using bicarbonate solutions. Seventy kinetic studies have been performed in 7 patients treated with 2 CAPD solutions containing 35 mmol/l (A) and 27 mmol/l (B) of bicarbonate. The changes in dialysate bicarbonate concentration at different dwell times were correlated with bicarbonate blood levels. Furthermore after 2 hours of dwell time and at subsequent observations, no differences in dialysate bicarbonate concentration were found between A and B solutions at the same bicarbonatemia. Thus a feedback between bicarbonate absorption and bicarbonate blood concentration was observed. If the amount of bicarbonate transferred to the patient is over the metabolic acid production, bicarbonatemia will rise: consequently bicarbonate dialysate absorption will decrease. After a few days, an equilibrium point will be reached. In this condition the bicarbonate absorption is equal to metabolic acid production and, in stable clinical conditions, a stable acid base status will be maintained by the patient. Our studies empirically demonstrated that the equilibrium is reached when a difference of 5 mmols between blood and inlet dialysate bicarbonate concentration is observed. Consequently to achieve 25 mmol/l of bicarbonatemia, the bicarbonate concentration of CAPD solution should be about 30 mmol/l.

Acetates↗
PubMed1988

Epidemiological and genetic study of 200 cases of oral cleft in the Emilia Romagna region of northern Italy.

Epidemiological and genetic variables in clefts were analyzed during the years 1978-1986 in a case-control study of congenital malformations in the Emilia Romagna region of northern Italy. Among 150,168 newborns, 200 cases of cleft were detected, yielding a prevalence of 1.33 per 1,000. These clefts consisted of 112 (0.075%) cases of cleft lip with or without cleft palate (CL +/- P) and 88 cases (0.058%) of cleft palate (CP). Coexisting abnormalities were found in 32% of cases. The heritability coefficient of CL +/- P was 0.84. No cluster in time or space could be demonstrated. Epilepsy was the only maternal risk factor found to be correlated with clefts. A predominance of males was found among CL +/- P cases.

Cleft Lip↗
PubMed1988

High-flux haemodialysis with 1.5 m2 modified cuprammonium rayon membrane: technical and clinical evaluation.

The feasibility and reliability of a short dialysis technique performed with standard dialysis equipment and a modified cuprammonium rayon hollow-fibre filter has been studied. The hydraulic response of the filter and membrane to high blood flows and transmembrane pressures were tested in vitro and the maximal clearances of different solutes achievable during high-flux bicarbonate dialysis were studied in vivo. Clinical studies were undertaken to evaluate the long-term effects of the short, highly efficient dialysis therapy. Six patients were treated for more than a year with single-pass bicarbonate dialysis with a blood flow of 500 ml/min, dialysate flow of 700 ml/min, and average duration of 150 min/session three times weekly. The treatment showed an adequate efficiency with an average KT/V greater than 1. All patients obtained an average blood urea nitrogen during the study of less than 80 mg/dl and an average protein catabolic rate of 0.9 g/kg per 24 h. The treatment was well tolerated by all patients and, on echocardiography, no significant changes in myocardial function were detected after one year of therapy. The treatment is efficient, well tolerated, simple to monitor and does not require the use of synthetic membranes or machines with advanced technology. Thus the reduction of dialysis treatment time is feasible in all centres at a relatively low cost.

Adult↗
PubMed1988

Renal functional reserve in pregnancy.

Creatinine clearance has been evaluated under baseline conditions and after acute protein load in five normal and 29 pregnant women at different stages of pregnancy without evidence of renal disease. After a 3-h period in which creatinine clearance was measured hourly (resting GFR), a meal containing 80 g of proteins was administered and creatinine clearance was measured hourly for 4 h (test GFR). Resting GFR in normal subjects averaged 104 +/- 22.5 ml/min per 1.73 m2, the wide variation being due to different dietary, protein intake (from 0.3 to 1.2 g of protein per kg body weight). In the pregnant women the resting GFR increased progressively from the first month (99.8 +/- 12.8 ml/min per 1.73 m2) to the last month of gestation (149.6 +/- 12.5 ml/min per 1.73 m2). All subjects showed a significant increase of GFR after protein load although the greatest difference between the resting and the test GFR was detected in the first trimester. Inulin clearance was also measured in seven subjects after protein loading to compare creatinine and inulin clearance values. The two clearance values did not differ significantly, showing that creatinine can be safely used as a reliable marker for measuring GFR. Test GFR averaged 163.3 +/- 4.1 ml/min per 1.73 in normal subjects and 163.8 +/- 6.5 ml/min per 1.73 m2 in pregnant women without any relationship with the stage of pregnancy. The identity of test GFR both in normal subjects and in pregnant women suggests that this parameter is likely to be related to the functioning renal mass, and represents the filtration capacity of the kidney.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Technical and clinical evaluation of a new polyamide hollow fiber hemofilter for CAVH.

We carried out an in-vivo and in-vitro evaluation of a new polyamide hollow fiber hemofilter especially designed to operate under conditions of low pressure and low blood flow, such as in continuous arteriovenous hemofiltration (CAVH). The results obtained suggest that this filter is a prototype of a new generation of hemofilters especially designed for CAVH. Its low resistance permits its use even in patients with severe hypotension. The high blood flows achieved at a given pressure reduce the risk of clotting and increase the ultrafiltration rate. When an average ultrafiltration of 20-25 ml/min is achieved in 24 hours CAVH becomes very efficient, and alternative techniques to increase its efficiency are no longer required.

Acute Kidney Injury↗
PubMed1988

Comparison of four different short dialysis techniques.

The goal of shortening dialysis treatment time has stimulated the development of new, highly efficient dialytic strategies. In this study the Authors compared four different short dialysis treatments in terms of efficiency, clinical tolerance, technological investment and costs: 1) Rapid bicarbonate dialysis with 1.5 sq.m. cuprophane membrane; 2) High flux biofiltration with 1.2 sq.m. AN69S hollow fiber membrane; 3) Hemodiafiltration with 1.2-1.9. sq.m. polysulphonic hollow fiber hemodiafilters, and 4) High flux hemodiafiltration with two serial hemodiafilters with AN69s membrane (total 2.4 sq.m.). Hydraulic properties and solute clearances at different blood flows (300-500 ml/min) were tested for each technique. Once the optimal operative level was established three patients were treated with each technique for at least six months. Since BUN clearance averaged 310 ml/min, the treatment duration varied from 120 to 180 min/session with KT/V always higher than 1. The average protein catabolic rate was 0.9 g/kg/24h. Clinical tolerance was generally good, slightly better in treatments with a high convective component. Despite the greater efficiency of treatment No. 4, the technological requirements and costs are such that the others are currently more feasible and acceptable in clinical routine. The study demonstrates that reduction of dialysis treatment time is possible in all centres in a selected population with adequate blood access. Treatment No. 1 can even be performed with standard equipment and cuprophan membranes, while bicarbonate in the dialysate is mandatory. The real limit to shortening treatment time seems to be related to the maximal rate of ultrafiltration achievable in the patient during dialysis.

Adult↗
PubMed1987

Arteriovenous hemodiafiltration associated with continuous arteriovenous hemofiltration: a combined therapy for acute renal failure in the hypercatabolic patient.

To increase the efficiency of continuous arteriovenous hemofiltration (CAVH) in cases of severe catabolism, we used a modified CAVH treatment, called arteriovenous hemodiafiltration (AVHDF), in 4 patients. The transport of solutes was increased by providing the infusion of a counter current flow of urea-free solutions in the UF compartment of a standard CAVH circuit. Patients were treated with standard CAVH and, when a more efficient treatment was required, intermittent daily sessions of AVHDF were performed using the same filter and lines. The urea kinetic study enabled the calculation of the time needed to perform AVHDF, in addition to standard CAVH, to maintain the blood urea nitrogen (BUN) level under control. A dialysate flow rate of 300 ml/min made it possible to increase the urea nitrogen mass transfer rate from 10 to 65 mg/min and the clearance from 10.5 to 37.5 ml/min. The addition of AVHDF to CAVH enabled the control of BUN levels in the 4 patients affected by acute renal failure and a severe catabolic state. The technique is simple, does not require additional devices, and maintains the advantages of CAVH providing a better efficiency in terms of solute removal.

Acute Kidney Injury↗
PubMed1987

Solute and water transport during continuous arteriovenous hemofiltration (CAVH).

The transport mechanisms governing solvent and solute removal during CAVH were elucidated on the basis of in vitro and in vivo observations. Using a typical hemofilter (Diafilter D-20, AMICON), filtration rate rose with inlet blood flow rate until an asymptote was reached at blood flows of approximately 150 ml/min. The onset of the asymptote coincided with transition from a regime controlled by oncotic pressure (filtration pressure equilibrium), to one governed by simple Darcy's law filtration behaviour. Subsequent measurements showed that under clinical conditions, CAVH is generally in the pre-asymptotic regime and operates at filtration pressure equilibrium. These observations offer the theoretical bases for a new design for CAVH hemofilters. As a possible corollary, middle-molecule sieving coefficients were found to be stable with time during CAVH in vivo, whereas in chronic mechanical hemofiltration they declined significantly during clinical treatment. The sieving coefficients, however, were lower in mechanical hemofiltration from the beginning of the session. These observations suggest that the measured sieving coefficient for a membrane is not necessarily a constant directly and solely related to the membrane standard reflection coefficient for a given solute. Concentration polarization and the ultrafiltration rate per unit of surface area may in fact have a major effect on the final concentration of solutes in the ultrafiltrate.

Biological Transport↗