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Biomedical subjects

C Vullo

Publications and source records attributed to C Vullo.

At least 19 recordsLinked to original sources

Right ventricular failure: physiology and assessment.

Right ventricular function can be altered in several disease states involving lungs and heart. Severe right ventricular dysfunction is a major determinant of outcome in such situations, and may strongly influence clinical management. The complex geometry of the right ventricle and the different physiology with respect to the left ventricle make the right ventricular failure difficult to define and assess. The response to increased afterload is the main determinant of right ventricle physiology in pathologic conditions. This consists of right ventricular hypertrophy and enlargement, with reduced coronary blood flow to the right ventricular wall, dilation of tricuspid annulus and displacement of interventricular septum. This latter change involves the left ventricular diastolic function, which is reduced by leftward septal shifting. In right ventricle myocardial ischemia and infarction the primum movens of altered right ventricular function is not an increase in afterload, but the ischemic involvement of the right ventricle, more often in the setting of an inferior acute myocardial infarction. The assessment of right ventricular failure is based on thermodilution by pulmonary artery catheter, contrast and radionuclide ventriculography, echocardiography, and magnetic resonance. Among these techniques, thermodilution and echocardiography play a relevant role in clinical scenarios, being readily available and feasible bedside.

Heart Failure↗

[Cardiac protection is a clinical evidence].

AIM: Anaesthetics may have protective effect against myocardial ischemia. We aimed to investigate if sevoflurane administration could exert myocardial protection during following coronary occlusion in patients with coronary artery disease. METHODS: a). EXPERIMENTAL DESIGN: prospective, randomized study. b). SETTING: University Hospital, cardiac surgical operative theatre. c). PATIENTS: 42 patients with coronary artery disease, scheduled to undergo coronary surgery. INCLUSION CRITERIA: severe coronary stenosis of anterior descending coronary artery; no collateral flow on angiography; at least two normokinetic segments in the myocardial region supplied by the vessel being bypassed. PATIENTS were randomized to receive (group S) or not (group C) sevoflurane administration for 15 min just before coronary occlusion. d). INTERVENTIONS: Transoesophageal Tissue Doppler echocardiographic examination of myocardial systolic and early diastolic velocities in both groups basally and 60 s after coronary occlusion by the surgeon. e). MEASURES: systolic and early diastolic velocities were registered by Tissue Doppler from a long-axis view of the interventricular septum or the anterior wall of the left ventricle. RESULTS: In group C a significant reduction of systolic and diastolic intramyocardial velocities was found during myocardial ischemia due to coronary occlusion. CONCLUSION: Treatment with sevoflurane before coronary occlusion seem effective in reducing functional myocardial impairment due to ischemia.

Aged↗

HLA class I diversity in Kolla Amerindians.

Human leukocyte antigen (HLA) class I polymorphism was studied within a population of 70 unrelated Kolla Amerindians from the far northwest of Argentina close to the Bolivian border. The results indicate that the HLA-A, -B, and -C alleles typical of other Amerindian populations also predominate in the Kolla. These alleles belong to the following allele groups: HLA-A*02, *68, *31, *24, HLA-B*35, *15, *51, *39, *40, *48, and Cw*01, *03, *04, *07, *08, and *15. For the HLA-A locus, heterogeneity was seen for HLA-A*02 with A*0201, *0211, and *0222; and for A*68 with *68012 and *6817, the latter being a novel allele identified in this population. Analysis of HLA-B identified heterogeneity for all Amerindian allele groups except HLA-B*48, including the identification of the novel B*5113 allele. For HLA-C heterogeneity was identified within the Cw*07, *04, and *08 groups with Cw*0701/06, *0702, *04011, *0404, *0803, and *0809 identified. The most frequent "probable" haplotype found in this population was B*3505-Cw*04011. This study supports previous studies, which demonstrate increased diversity at HLA-B compared with HLA-A and -C. The polymorphism identified within the Kolla HLA-A, -B, and -C alleles supports the hypothesis that HLA evolution is subject to positive selection for diversity within the peptide binding site.

Alleles↗

HLA-A*6817, identified in the Kolla Amerindians of North-West Argentina possesses a novel nucleotide substitution.

Analysis of HLA polymorphism of the indigenous populations of Central and South America has identified many alleles not seen previously in other populations. We have described a novel allele, B*5113, previously in a Kolla Amerindian individual from North-West Argentina. Here we present a second novel allele from this population: A*6817, which differs from its closest neighbour A*68012 by a single substitution at nucleotide 419. This substitution of adenosine 419 A*68012 for thymidine in A*6817 results in a novel amino acid change (aspartate to valine) at residue 116.

Argentina↗

Safety profile of the oral iron chelator deferiprone: a multicentre study.

In previous trials, the orally active iron chelator deferiprone (L1) has been associated with sporadic agranulocytosis, milder forms of neutropenia and other side-effects. To determine the incidence of these events, we performed a multicentre prospective study of the chelator. Blood counts were performed weekly, and confirmed neutropenia mandated discontinuation of therapy. Among 187 patients with thalassaemia major, the incidence of agranulocytosis (neutrophils < 0.5 x 109/l) was 0.6/100 patient-years, and the incidence of milder forms of neutropenia (neutrophils 0.5-1.5 x 109/l) was 5.4/100 patient-years. All cases of neutropenia resolved after interruption of therapy. Neutropenia occurred predominantly in non-splenectomized patients. Nausea and/or vomiting occurred early in therapy, was usually transient and caused discontinuation of deferiprone in three patients. Mild to moderate joint pain and/or swelling did not require permanent cessation of deferiprone and occurred more commonly in patients with higher ferritin levels. Mean alanine transaminase (ALT) levels rose during therapy. Increased ALT levels were generally transient and occurred more commonly in patients with hepatitis C. Persistent changes in immunological studies were infrequent, although sporadic abnormalities occurred commonly. Mean zinc levels decreased during therapy. Ferritin levels did not change in the overall group but decreased in those patients with baseline levels > 2500 microgram/l. This study characterized the safety profile of deferiprone, and, under the specific conditions of monitoring, demonstrated that agranulocytosis is less common than previously predicted.

Agranulocytosis↗

Interleukin 2 induction of proliferation in resting T lymphocytes requires contact with monocytes.

Resting human T cells are known to express significant numbers of intermediate but none or barely detectable low and high affinity IL-2 receptors (IL-2R). IL-2 alone failed to induce proliferation in these cells. However, in presence of small proportion of autologous monocytes, as low as 22 pM, IL-2 induced high levels of proliferation in resting T cells. Introduction of a semi permeable membrane between the two cell types or addition of an anti-CD11b mAb inhibited such induction of proliferation by IL-2. Neither recombinant IL-1 nor IL-1-containing cell-free extracts from activated monocytes substituted for intact monocytes. Autologous B cells failed to replace monocytes. Using antigen-specific cloned human T cells we have shown a lack of requirement for antigen. The proliferation was inhibited by anti-IL-2R alpha mAb. IL-2 appears to be unique since neither IL-4 nor IL-6, alone or in presence of monocytes, led to induction of proliferation in resting T cells. Combination of IL-2 and monocytes induced proliferation in all T cell subpopulations (CD4+, CD8+, CD45RA+ and CD45RO+) and antigen-specific clones examined. It also induces mRNA and surface expression of IL-2R alpha, appearance of high affinity IL-2R and induction of proliferation in large proportions of T cells. As in humans, the IL-2 induction of proliferation in murine resting T cells required contact with syngeneic monocytes, suggesting that such a mechanism of T cells activation is highly conserved.

Animals↗

A novel HLA allele, HLA-B*5113, identified in the Kolla Amerindians of North-West Argentina.

A novel HLA-B51 allele, B*5113, was identified in a Kolla Amerindian individual from North-West Argentina. HLA-B*5113 differs from B*51011 by two nucleotide substitutions, one synonymous, the other nonsynonymous. The resulting amino acid difference at residue 116 in the HLA-B molecule's peptide binding site is likely to affect the nature of the peptides which bind to this molecule. The finding of this novel allele supports previous findings of increased diversity at HLA-B in Amerindian groups.

Alleles↗

A multi-center safety trial of the oral iron chelator deferiprone.

Deferiprone, also known as L1, is an orally active iron chelator that has been studied extensively in clinical trials. The sporadic occurrence of agranulocytosis in association with deferiprone and the highly variable frequency of other possible side effects such as arthralgia have created uncertainty about the true incidence of deferiprone-related complications. A multi-center, 1-year trial was initiated to determine the safety profile of deferiprone. Using the Apotex formulation of deferiprone, 187 patients with thalassemia who were unable or unwilling to use deferoxamine were enrolled in four centers; 162 patients completed one year of therapy. Agranulocytosis (ANC < 500/mm3) occurred in one patient after 15 weeks of treatment, was not accompanied by infection and resolved following treatment with G-CSF. Nine other subjects developed less severe neutropenia (ANC 500-1500/mm3) with the lowest absolute neutrophil count reaching 500-1250/mm3. The neutropenia in these patients developed after 1-50 weeks of therapy, frequently accompanied febrile illnesses, and occurred predominantly in non-splenectomized patients. Reasons other than neutropenia for discontinuing use of deferiprone included nausea (4), voluntary withdrawal (3), high ALT (2), platelet count < 100,000/mm3 (2), low but unconfirmed ANC (1), protocol violation (1) fatigue (1), and depression (1). Mean ALT levels rose within three months of therapy and stabilized thereafter. Arthralgia and nausea and/or vomiting occurred in 6% and 24% of subjects, respectively. In this multi-center trial with weekly monitoring of blood counts, the incidence of agranulocytosis was 0.58 per 100 patient-years, and the frequency of agranulocytosis after one year was 0.5%. These findings support the safety of this formulation of deferiprone, using the careful monitoring system employed in this trial.

Administration, Oral↗

Psychosocial integration of adolescents and young adults with thalassemia major.

UNLABELLED: The aim of this study was to explore the effect of thalassemia major on the psychosocial adjustment of adolescents and young adults. DESIGN: unmarried adolescent and young adult patients were asked to fill in an ad hoc questionnaire; a semi-structured interview exploring marriage and family life was done with married patients. SAMPLE: group A: 90 unmarried patients, 50% females and 50% males, aged 14-22 years. The control group was formed by 100 matched subjects; group B: 19 thalassemic married subjects, 6 males and 13 females, aged 28-45 years, 7 patients had children and 12 did not. RESULTS: group A: subjects with thalassemia had normal psychological and social development and scored better than their normal peers in tests investigating social adjustment, self-esteem and self-description. Moreover the family relationships of adolescents with thalassemia appeared to be stronger than those reported by normal controls; group B: the behavior of thalassemic couples did not differ from the one observed in non-thalassemic couples in the course of previous investigations. CONCLUSIONS: Our data shows that neither thalassemic adolescents nor thalassemic married, well-treated, young adults differ significantly from the healthy young people in their ability to cope with life's difficulties both in adolescence and marital life.

Adaptation, Psychological↗

Clinical experience using the Androderm testosterone transdermal system in hypogonadal adolescents and young men with beta-thalassemia major.

beta-Thalassemia major is associated with a high prevalence of hypogonadotropic hypogonadism affecting adolescents and young men with this disease. The pharmacokinetics of Androderm, a non-scrotal permeation-enhanced testosterone transdermal system, was previously studied in this population using three application regimens designed to mimic the nocturnal secretion and circadian patterns of testosterone production characteristics of puberty and young adulthood. In regimen I, designed for prepubertal 14 to 16 year-olds, a single Androderm patch (2.5 mg/day nominal delivery rate) is applied at night and removed 12 hours later in the morning. In regimen II, designed for partially virilized 17 to 19 year-olds, a single Androderm patch is applied nightly for 24 hours. In regimen III, intended for virilized men aged 20 years and older, two Androderm patches (total dose of 5 mg/day) are applied nightly for 24 hours. This report presents the results of a 12-month open label study using these three Androderm regimens to treat nine hypogonadal males with beta-thalassemia (ages 16.8 to 31.8 yr). Our data show that Androderm produced physiologically appropriate testosterone levels, lowered SHBG levels, promoted growth and virilization, increased bone mineral density, and was generally well tolerated in this population of hypogonadal adolescents and young men with beta-thalassemia.

Administration, Cutaneous↗

Growth and development in thalassaemia major patients with severe bone lesions due to desferrioxamine.

UNLABELLED: Nine transfusion-dependent beta-thalassaemia major patients (seven males and two females), aged 4-15 years, with growth retardation and severe rickets-like radiological lesions due to continuous subcutaneous chelation therapy with desferrioxamine (45-75 mg/kg body weight, 6-7 time/week), were seen in our centre during the last 8 years. Serum ferritin levels ranged from 976 to 4115 micrograms/l. There was a progressive decline in growth velocity in these patients 2-3 years before the appearance of rickets-like radiological lesions. All patients underwent surgery to correct genu valgum and/or slipped capital epiphyses. The final height was below the 3rd percentile in six patients (SDS: from -2.9 to -5.2). The short stature was mainly due to a disproportion between upper and lower segments. Six of the patients had an associated sensorineural hearing loss. CONCLUSION: Our data emphasize the importance of an accurate surveillance of the toxic effects of desferrioxamine treatment and warn of the risk of overtreating patients with low iron overload and also suggest a possible individual idiosyncrasy to the adverse effects of chelation therapy.

Adolescent↗

Deficiency of two red-cell flavin enzymes in a population in Sardinia: was glutathione reductase deficiency specifically selected for by malaria?

In two areas in Italy where malaria was endemic--in the Po delta and Maremma on the west coast--we have found a high prevalence of an inherited flavin-deficient red cell in the normal population, suggesting selection by malaria. This study in Sardinia enabled a direct comparison of red-cell activities of FAD-dependent glutathione reductase (EGR) and FMN-dependent pyridoxine phosphate (PNP) oxidase in an ethnically homogeneous population, between two coastal villages where malaria was endemic from 300 B.C. and two mountain villages with no history of malaria. Both enzyme activities were significantly lower on the coast, and it did not seem that this could be explained by possible small differences in dietary riboflavin. As was thought to be the case in Ferrara and Grosseto, it is probable that a genetically controlled flavin-deficient red cell was selected for by malaria. Low EGR apoenzyme activity was more common on the coast, usually explaining the accompanying low basic EGR activity, and may also have been selected for by malaria. This adds to evidence from others that the mechanism of defence of a flavin-deficient red cell against malaria may be through EGR deficiency. It could also play a part in the protection given by heterozygous beta-thalassemia. The multifactorial protection of the population against malaria is discussed.

Adolescent↗

Effect of different treatment regimes on linear growth and final height in beta-thalassaemia major.

OBJECTIVE: The clinical picture of thalassaemia major has changed progressively over the years. Our study is a retrospective analysis of data on growth in a group of patients who have completed puberty spontaneously and have attained their adult height. Our objective was to evaluate the effect of different transfusion regimes and desferrioxamine administration on the growth pattern in beta-thalassaemia major. DESIGN AND PATIENTS: We studied 64 patients (28 males and 36 females). The patients were divided into three groups (A, B and C) according to the different transfusion regimes and the schedules of chelating therapy. Group A consisted of 16 patients who were transfused regularly at low haemoglobin levels (on average 8.5 g/dl) from an early age and started subcutaneous chelation therapy during adolescence. Group B consisted of 19 patients who were transfused regularly at high haemoglobin levels (on average 10 g/dl) from an early age and started subcutaneous therapy during childhood. Group C consisted of 29 patients who were transfused regularly at high haemoglobin levels (on average 10.5 g/dl) from an early age and started subcutaneous chelation therapy very early, at a mean age of 2 years. Standard auxological measurements were made at 3-monthly intervals throughout childhood and puberty until adult height was achieved. For group C patients the data on linear growth are provided only until the age of 12 years. RESULTS: Our study indicates that group A male and female patients did not grow significantly better than those in group B. Group C male and female patients, surprisingly, grew no faster than those who started chelation therapy late in childhood (group A). The most striking feature in the majority of both group A and B patients was reduced spurt in height at puberty. In addition, in both groups, a reduced sitting height due to spinal growth abnormality was found. An inverse correlation between sitting height and serum ferritin levels was observed in group A patients (r = -0.55, P < 0.05), whereas there was a direct correlation in group B patients (r = 0.42, P < 0.05). CONCLUSIONS: These data suggest that an ideal therapeutic regime has yet to be found which avoids the toxic effect of iron overload and on the other hand avoids interference with growth, secondary to desferrioxamine. Therefore we recommend that the growth of thalassaemia patients be monitored routinely at every follow-up visit and documented on growth velocity charts in order to detect early changes in their growth pattern and to establish an appropriate protocol for investigation and treatment.

Adult↗

Pattern of iron excretion in relation to haemoglobin level and iron load in 8 haematological patients following the administration of subcutaneous deferrioxamine.

Iron excretion following subcutaneous administration of deferrioxamine (DFO) was measured between two transfusions of packed red cells in 6 patients with beta-thalassaemia major on the high level Hb transfusion regime; and in a single 3-day period in 2 other patients, 1 with transfused beta-thalassaemia major and the other with haemolytic anaemia due to PK deficiency. The pattern of iron excretion did not change significantly during the period between the two transfusions and was found to be related to serum ferritin levels. The proportion of iron excreted in the stools was inversely related to the serum ferritin level. These observations on iron excretion are of practical importance in relation to DFO administration, especially when evaluated in thalassaemics with normal haemoglobin levels and low iron stores.

Adolescent↗