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Biomedical subjects

T Lombardo

Publications and source records attributed to T Lombardo.

At least 19 recordsLinked to original sources
PubMed2006

Modeling of soiling based on silica-soda-lime glass exposure at six European sites.

Samples of silica-soda-lime float glass, a material selected as a pertinent soiling sensor, were exposed for up to 28 months at four urban sites (Athens, Krakow, London and Prague) and at a semi-urban one (Monte Libretti, near Rome), sheltered from rain. This exhaustive experience permitted to complete and to test the generalisation ability of the results previously obtained on the same material, exposed according to the same protocol, during 24 months, at a single site (Paris). The model previously fitted for the Paris experiment, the Hill equation, could be successfully generalised for four other sites of exposure (Athens, Krakow, Prague and Rome). The analytical form of this model was interpreted in terms of a physical description of the soiling phenomenon. Some of the model coefficients were different from one site to another, depending on the specific environment of exposure (air pollution levels, meteorological factors), while the other ones were rather equivalent. The analysis of the model coefficients, on the one hand, led to an estimation of the period after which soiling is close to its saturation level, and on the other hand, it will permit to correlate these coefficients to the environmental factors, in order to select the most appropriate ones for building dose-response functions for soiling, with broad geographical application.

Journal Article↗
PubMed2006

Altered osteoprotegerin/RANKL ratio and low bone mineral density in celiac patients on long-term treatment with gluten-free diet.

Skeletal demineralization and mineral metabolism derangement are well-recognized features of untreated celiac disease (CD). Although treatment with a gluten-free diet appears to prevent bone loss while correcting skeletal demineralization in childhood, there is evidence that bone mineral density does not return to normal in celiacs diagnosed in adulthood. Osteoprotegerin (OPG), a member of the tumor necrosis factor receptor family, and ligand of receptor activator of NFkB (RANKL) are involved in the process of bone turnover and have been implicated in the pathogenesis of osteoporosis and other metabolic bone diseases. We measured OPG, RANKL, bone mineral density (BMD), and biochemical markers of bone turnover in 32 adult female premenopausal celiac patients on a gluten-free diet, and thirty age-matched healthy women. We correlated the OPG/RANKL ratio with the severity of bone loss. Celiac patients had a mean BMD lower than controls in lumbar spine and in the femoral neck. Serum levels of bone alkaline phosphatase (BAP, marker of bone formation), and urinary excretion of telopeptides of type I collagen (a marker of bone resorption) were significantly higher than in controls. Serum OPG and RANKL levels were significantly higher in CD patients than in controls, while the OPG/RANKL ratio was significantly lower in CD patients than in controls and was positively correlated with BMD at the spine. The role of elevated OPG in CD patients is unclear, but it might represent a compensatory mechanism against other factors that promote bone damage. Further studies are required to assess a possible therapeutic potential of osteoprotegerin in optimally treated celiacs with persistent osteopenia.

Adult↗
PubMed2000

Thalassaemic men affected by erectile dysfunction treated with transurethral alprostadil: case report.

The aim of this controlled clinical study, performed in a specialized institutional unit for thalassaemic men, was to consider the possibility of restoring erection in beta-thalassaemic patients with erectile dysfunction by administering E(1) prostaglandins (alprostadil) transurethrally. Four patients affected by beta-thalassaemia, aged between 32 and 52 years, and having an erectile dysfunction were included in the study. Each patient was given 500 microg alprostadil in the distal urethra. Response was evaluated by the erection assessment scale. The main outcome measures were: (i) the clinical study; (ii) FSH, LH, total and free testosterone plasma concentrations; and (iii) basal and dynamic Doppler sonography of cavernous arteries. The treatment produced a response of 3-4 on the erection assessment scale. Average minimum response time was 20 min, while average maximum response time was about 60 min. There was no evidence of significant side effects. Our hypothesis is that the delayed reaction was due to organ damage induced by iron load, causing a reduction or absence of elasticity in the interstitial tissue of the corpora cavernosa. Thus, we believe that treatment with alprostadil can be considered an effective, non-invasive therapy for thalassaemic patients with erectile dysfunction.

Adult↗
PubMed1997

Molecular basis of alpha-thalassemia in Sicily.

To evaluate the allelic frequency and genetic diversity of alpha-thalassemia defects in Sicily, both epidemiological and patient-oriented studies were carried out. For the epidemiological study, phenotypic data were collected on more than 1000 Sicilian individuals. Among them, 427 were explored at the molecular level for nine alpha-thalassemic variants known to be common in the Mediterranean region. Our data reveal an allele frequency of 4.1% for alpha(+)-thalassemia matching that of beta-thalassemia in this region. The presence of alpha0-thalassemia (--MEDI and --CAL) was observed only in the group of referred patients. Newly acquired nucleotide sequence data on the deletional breakpoint of --CAL allowed us to design a simple PCR-based procedure for exploring this allele. The data also provide additional information concerning the genetic mechanisms involved in such large deletions.

Adolescent↗
PubMed1996

High-dose intravenous desferrioxamine (DFO) delivery in four thalassemic patients allergic to subcutaneous DFO administration.

To test the hypothesis that allergy to desferrioxamine is not an immunologic mechanism, but arises from a local effect on the dermal mast cell, we have treated four patients who were not receiving chelation therapy because of hypersensitivity to standard subcutaneous (SC) therapy, with high-dose desferrioxamine (DFO) by the intravenous (IV) route. Three patients had central venous access ports implanted on the anterior chest wall. The fourth patient had the therapy delivered by the peripheral vein route. All patients had the drug delivered via an elastomeric infusor. Intravenous therapy was successful for all patients. During one year of therapy no local or systemic allergic manifestations were noted. In addition, no impairment of hearing or vision or any catheter complications were reported. A very high level of patient compliance to the therapy resulted in dramatically decreased iron stores and ferritin levels (2,759 ng/ml to 717.5 ng/ml) and a significant improvement in the clinical status of all patients. The absence of allergic episodes in this patient group after 1 year of i.v. therapy would strongly support the hypothesis that SC DFO allergy is related to a direct effect on dermal mast cells and is not an immunological reaction. This study suggests that patients with severe allergy to SC DFO can therefore safely receive their chelation therapy via the i.v. route.

Adolescent↗
PubMed1996

Laboratory evaluation of a new delivery system to improve patient compliance with chelation therapy.

As thalassaemia patients live longer, compliance with chelation therapy becomes more and more of a problem. Teenagers rebel against the continual need for treatment, and young adults with jobs, active social lives and families, find it hard to find the time to prepare and deliver their treatments. In an effort to find a solution to this problem, we evaluated a non-electronic, disposable pump (Infusor 5 ml/h, Baxter Healthcare) to determine its suitability for high dose desferrioxamine (DFO) infusions. We wanted an infusion time of 12 h to support overnight delivery in the patient's home. Because of DFOs viscosity, infusion times vary at different concentrations. We found the optimal prescription for total delivery within 12 h to be a dose of 70 mg/kg x patient's body weight diluted in constant volume of 40 ml of water for injection. Our tests were carried out in vitro and the results show that the 5 ml/h Infusor may be used to deliver high dose DFO chelation therapy within 12 h. The variability of the flow rate, dependent on the concentration of the solution, and the absence of a warning system, are more than compensated for by the simplicity of the pump.

Adolescent↗
PubMed1995

Cardiac iron overload in thalassemic patients: an endomyocardial biopsy study.

Secondary heart failure induced by organ siderosis is the main cause of death in patients affected by thalassemia major. At present it cannot be predicted whether heart siderosis is correlated with iron overload and little is known about the real cardiac histological pattern of post transfusional hemochromatosis in patients with thalassemia major and intermedia. The study aim was to evaluate cardiac iron overload by non invasive and invasive techniques. Fifteen thalassemic patients were investigated and endomyocardial biopsy performed in ten revealed different grades of endomyocardial iron overload with histochemical positivity. Non invasive techniques are not able to furnish an exact picture of the cardiac hemochromatosis. There was a significant correlation between serum ferritin and myocardial iron grade. Patients with elevated ferritin levels and poor compliance to chelating therapy are at high risk of severe heart hemochromatosis. It was seen that endomyocardial biopsy is a useful tool in studying myocardial iron.

Adult↗
PubMed1993

Radioimmunoscintigraphy with 99mTc-225.28S-F(ab')2 in cutaneous and ocular melanomas: cases of particular clinical interest.

In the attempt to contribute to a correct and early diagnosis of melanoma, this paper critically evaluates, in 40 patients with cutaneous localization and 20 with ocular localization, the results of immunoscintigraphy with 99mTc-225.28S-F(ab')2 and the clinical, instrumental and biopsy findings. While the cutaneous melanoma group is mainly composed of patients subjected to surgical exeresis of the lesion before radioimmunoscintigraphy (RIS), the ocular melanoma group is composed of patients with the primary lesion in situ or previously treated with contact radiotherapy. In the cutaneous melanoma group 5 cases presented falsely positive immunoscintigraphic findings, and only 2 falsely negative. In the ocular melanomas, the percentage of false negatives was higher (n = 7). This is probably attributable to the antigenic expressivity, higher in the metastases than in the primary melanomas. The cases of particular interest are discussed in relation to the clinical picture, to the instrumental examinations and to the histological findings. The work made it possible to contribute to a more correct interpretation of the RIS findings in the staging and follow-up of cutaneous and ocular melanomas.

Adult↗
PubMed1992

Genetic epidemiology of beta-thalassemia in Sicily: do sequences 5' to the G gamma gene and 5' to the beta gene interact to enhance HbF expression in beta-thalassemia?

The present epidemiological study of the molecular characteristics of beta-thalassemia in Sicily was prompted by the disparate phenotypic expression (in clinical status and absolute HbF level) observed in two beta-thalassemic homozygotes who were also homozygous for the beta-like globin gene cluster haplotype III. We suspected that polymorphisms within haplotype III could be the cause for the discrepancy. Based on the association of particular conformations of the (AT)xT(y) motif (-540 5' to the beta gene) with milder forms of thalassemia and sickle cell anemia, 38 homozygous beta-thalassemia patients were studied to define their haplotypes, the -158 site 5' to the G gamma gene (linked to haplotype III) and the structure of the (AT)xT(y) motif. We found that the patient who was phenotypically mild and homozygous for beta-thalassemia, haplotype III, and the -158 C----T mutation was homozygous for the rare (AT)9T5 motif. In contrast, the patient homozygous for beta-thalassemia, haplotype III, and the -158 mutation, but exhibiting a severe clinical course, was homozygous for the (AT)7T7 configuration. Others have suggested that (AT)9T5 is a negative regulatory protein binding sequence, and it is a silent carrier state for beta-thalassemia. The usual configuration (AT)7T7, has considerably less affinity for regulatory protein binding, and it is the most common configuration in Sicilian beta-thalassemics (67 of the 78 chromosomes studied). Within the 38 patients studied, seven were informative because they had various combinations of the (AT)9T5 and (AT)7T7 motif, and the -158 C----T mutation. The results in these patients suggest that only the co-presence of the (AT)9T5 configuration and a C----T change at -158 5' to the G gamma gene is associated with high HbF expression and a mild clinical phenotype. We postulate that these two regions of the beta-like globin gene cluster interact, when endowed with the proper sequences, to enhance the expression of HbF secondary to anemia.

Adolescent↗
PubMed1992

Presence of an African beta-globin gene cluster haplotype in normal chromosomes in Sicily.

African admixture in Sicily has been long suspected because of the presence of the sickle gene. Nevertheless, the degree of African admixture cannot be derived from the study of HbS frequency, since this gene was most likely expanded by the selective pressure of malaria, for a long time endemic to the region. We have examined 142 individuals from the Sicilian town of Butera (12% sickle trait) to search for other markers of the globin gene cluster less likely to be selected for by malaria. The TaqI polymorphism in the intervening sequences between the two gamma genes is informative. We have found only two instances of this African marker (TaqI(-)) among 267 normal chromosomes, demonstrating that the admixture occurred at a much lower level than previously thought.

Adolescent↗
PubMed1989

Nucleotide variations in the 3' A gamma enhancer region are linked to beta-gene cluster haplotypes and are unrelated to fetal hemoglobin expression.

Molecular cloning and sequence analysis of a nondeletion form of Sicilian beta o hereditary persistence of fetal hemoglobinemia (HPFH) (mutation in IVS2 nt1 position) homozygous for haplotype III revealed the presence of four sequence variations: C----T at -158 5' to G gamma, T----C at +2285, C----A at +2476, and A----G at +2676, all 3' to A gamma. The latter three variations in the putative A gamma enhancer are identical to those observed in the case of Seattle HPFH. However, a severe beta o-thalassemia case from Algeria (mutation in IVS1 nt1 position), also homozygous for haplotype III, revealed the same nucleotide variation, albeit an inefficient HbF production. We conclude that the variations in the A gamma enhancer element do not play a role in the regulation of HbF production. To assess both the linkage of these sites with the beta-cluster haplotype and the extent of the polymorphism, we examined several black and Mediterranean chromosomes, by PCR amplification followed by both EspI digestion and oligonucleotide hybridization. Our data indicate that these sequence variations in the enhancer element are absent in Mediterranean haplotypes I, V, and VII but are consistently associated with Mediterranean haplotypes II, III, and IX, as well as with the black beta c-associated haplotype. The common feature of all the latter haplotypes is the presence of a polymorphic PvuII site between A gamma and psi beta, which is thus in linkage disequilibrium with the variations in the A gamma enhancer.(ABSTRACT TRUNCATED AT 250 WORDS)

Base Sequence↗
PubMed1988

Beta S gene in Sicily is in linkage disequilibrium with the Benin haplotype: implications for gene flow.

Hemoglobin beta-like gene cluster haplotypes defined by restriction enzyme polymorphic sites are useful in determining the origin of the beta S gene found in several human populations. We present here evidence that the beta S gene found among Sicilians is associated with the same haplotype observed among sickle cell anemia patients from Central West Africa. In addition, this haplotype is either nonexistent or very rare among normal Sicilian individuals. We conclude that the beta S gene was introduced to Sicily from North Africa and that the gene flow originated in Central West Africa and traveled north through historically well-defined trans-Saharan commercial routes.

Anemia, Sickle Cell↗
PubMed1987

Relationship of type A behavior pattern in smokers to carbon monoxide exposure and smoking topography.

Stress-related physiological factors have been proposed to mediate the Type A behavior pattern (TABP) and coronary heart disease (CHD). However, collateral behavioral factors, such as the exaggerated consummatory response patterns of Type As, may also be involved. Study 1 examined this hypothesis by comparing exposure to cigarette smoke in 42 graduate and undergraduate student smokers assessed for the TABP. After controlling for smoking rate and Federal Trade Commission cigarette carbon monoxide yield, Type As' alveolar carbon monoxide (COa) levels were higher than Type Bs', and Jenkins Activity Survey scores were correlated with COa. To determine the source of this difference, we measured smoking topography in 10 Type As and 10 Type Bs in Study 2. Type As and Type Bs did not differ in number of puffs taken or puff volume, but Type As' inhalation duration was 70% longer than Type Bs'. These results suggest that consummatory behaviors of Type As may help account for the Type A-CHD relationship for smokers. Due to increased smoke exposure, Type A smokers may also be at greater risk for cancer and lung disease than Type B smokers.

Adolescent↗
PubMed1986

Heterogeneity of haplotypes among patients with severe Cooley disease in Eastern Sicily.

There is a large variation of clinical severity among thalassemic patients in Sicily. A heterogeneous molecular basis has already been demonstrated among the patients presenting with thalassemia intermedia. The same approach, based mostly on linked haplotypes of the beta gene cluster polymorphisms and in some cases on the demonstration of the molecular defect itself, was used to investigate 55 patients presenting with severe Cooley anemia, all maintained under permanent transfusion regimen. A large heterogeneity was demonstrated in the observed haplotypes, and only a limited overlap with those already found in thalassemia intermedia. It has been noted that many of the patients are compound heterozygotes, the various observed associations making the antenatal diagnosis at the DNA level difficult in the near future.

Adolescent↗
PubMed1986

Haplotype VI associated beta + thalassaemia intermedia. First Italian case.

We report the study of a family originating from eastern Sicily with mild beta thalassaemia intermedia which is similar both at a molecular level and in clinical form to that called "beta + thalassaemia intermedia-Portuguese type". Our patients were homozygous beta + thalassaemics with high HbA2 and low HbF levels. The mild clinical course was as a result of their age and because regular blood transfusion was established only in adulthood. All of the heterozygote parents were asymptomatic with a blood picture and haemoglobin pattern typical of beta thalassaemia. Studies at a molecular level revealed no abnormalities in the beta-like globin gene cluster and excluded the presence of a deletional form of alpha thalassaemia. Restriction enzyme site polymorphisms around the beta gene cluster showed that all patients were homozygous for the haplotype described as VI. Comparison of these homozygous haplotypes with the Portuguese ones revealed a clear difference in the polymorphic Pvu II site. In all Sicilian homozygous cases, this site was present on one chromosome and absent on the other. Therefore our hypothesis is that Portuguese beta + thalassaemia intermedia is different from the Sicilian type.

Adult↗
PubMed1984

A leftward deletional alpha+ thalassemia found in East Sicily in conjunction with heterozygous beta-thalassemia.

Two types of alpha+ thalassemia (-alpha l) have been described, respectively termed leftward and rightward, which correspond to nonhomologous crossing-over in different homology zones X and Z within the alpha-globin gene cluster. Up to now the leftward type has been described only in Asiatic populations, whereas the rightward type is universally distributed. We report here a first case of leftward deletion observed in a Sicilian male. This raises the question of an identical or not crossing-over event.

Aged↗