Gavino Faa

Iron chelating agents in clinical practice

Abstract The relevance of iron chelators in medicine has increased in recent years. Iron is essential for life but it is also potentially more toxic than other trace elements. This is due to the lack of effective means to protect human cells against iron overload and to the role of iron in the generation of free radicals. To protect patients from the consequences of iron toxicity, iron chelating agents have been introduced in clinical practice. Unfortunately, the ideal chelator for treating iron overload in humans has not been identified yet. The aim of this review is to report the experience with desferrioxamine therapy in patients affected by β-thalassemia major according to: bioavailability; mechanism of interactions with hepatocellular iron: release of iron chelates and their excretion; impact of iron chelation on survival in thalassemia patients and side effects of prolonged therapy. Problems related to the development of non-toxic oral iron chelators are also discussed, with particular emphasis on the preliminary data on usefulness and safety of deferiprone (L1), recently evaluated in different clinical trials. Iron chelating therapy has been introduced, in recent years, even in the therapy of disorders not characterized by iron overload. Here the following new therapeutic indications are discussed: adult respiratory distress syndrome, myocardial ischemia, cancer and malaria.

Uneven hepatic iron and phosphorus distribution in beta-thalassemia

BACKGROUND/AIMS Determination of hepatic iron concentration is crucial in the evaluation of iron-storage disease. Iron content is normally determined in a part of a needle liver biopsy and the value obtained is considered to be representative of the iron concentration in the whole liver. To evaluate the reliability of this procedure, we studied iron distribution in the liver of two beta-thalassemic patients. Since the transport of intracellular iron is mediated by phosphates, we also studied the hepatic phosphorus distribution. METHODS At autopsy, a liver slice extending from the left to the right lobe was divided into 51 and 49 samples, respectively. Each specimen was subdivided into two parts: one of them was paraffin-embedded and utilized for the histochemical detection of iron; the second part was analyzed for iron and phosphorus content by induced coupled plasma atomic emission spectroscopy. RESULTS The histological picture of both livers was characterized by portal and periportal fibrosis associated with iron storage of different degree, without cirrhosis. The mean iron concentration of the liver was 20,631 +/- 4903 micrograms per g of dry tissue (micrograms/g dt) and 13,901 +/- 1976 micrograms/g dt, respectively. A striking variability in iron content between samples was also found: iron concentration ranged from 11,537 to 32,347 micrograms/g dt in the first case and from 6257 to 16,493 in the second case. We even observed regional differences in iron concentration, with a preferential peripheral accumulation in both cases and a tendency of the left compartment of the liver to accumulate more iron in the first case. Histochemical analyses confirmed the uneven iron distribution even at the acinar level, showing iron mainly being stored in hepatocytes and Kupffer cells of zone 1 of the acinus, with decreasing amounts of iron in zones 2 and 3. The mean hepatic phosphorus concentration was 6662 +/- 1300 micrograms/g dt (range: 4348-9947) and 7502 +/- 986 micrograms/g dt (range: 5844-90,282), respectively. The regional distribution of phosphorus was similar to that observed for iron. A strict correlation between iron and phosphorus content was also observed. CONCLUSIONS Our data show that: 1) iron and phosphorus are unevenly distributed in the beta-thalassemic liver, even in the non-cirrhotic stages; 2) a regional pattern of iron and phosphorus distribution is evident, characterized by higher concentrations at the periphery of the liver; 3) the observed uneven distribution of iron and phosphorus implies that their content determined in a small liver sample cannot be considered as absolutely representative of the mean hepatic iron concentration. Therefore, iron concentrations determined in a part of a needle liver biopsy should be interpreted with caution in monitoring the efficacy of the iron-chelating therapy in beta-thalassemic patients.

Marked interindividual variability in renal maturation of preterm infants: lessons from autopsy

The kidney of low birthweight preterm infants is characterized by a reduced number of mature nephrons at birth. The aim of the present study was to determine whether, in preterms, active glomerulogenesis occurs in the postnatal period and whether it may compensate the reduced number of nephrons developed during the intrauterine life. Kidney samples were obtained at autopsy from 8 human fetuses, 12 premature infants, and 3 term newborns. Glomerulogenesis, as measured by radial glomerular count (RGC), was markedly decreased in all preterm infants as compared with term newborns. A marked interindividual variability was detected in the level of glomerulogenesis, which, in the vast majority of cases, did neither correlate with the gestational age at birth nor with birthweight. Active glomerulogenesis, as demonstrated by the presence of S-shaped bodies in the subcapsular region, was present in all preterm infants in the perinatal period, but it ceased in a preterm surviving for 3 months. Our data show that active glomerulogenesis continues even after birth for a short period, although it is not able to compensate a marked oligonephronia at birth. As a consequence, the incomplete nephrogenesis typical of all extremely low birthweight preterm infants possibly results in a persistent oligonephronia which should likelihood represent a major risk factors of progressive renal disease in adulthood.

Uneven hepatic copper distribution in Wilson's disease

BACKGROUND/AIMS Determination of hepatic copper concentration is important in the diagnosis of Wilsons disease. We studied copper distribution in the cirrhotic liver of a patient who died of Wilsons disease. METHODS A liver slice extending from the left to the right lobe was divided into 38 samples. Each sample was analyzed for copper content by Induced Coupled Plasma Atomic Emission Spectroscopy. RESULTS The mean copper concentration in the liver was 1370 micrograms/g dt. A striking variability, up to 2-3-fold, in copper levels was observed between the samples: the copper concentration ranged from 880 to 2100 micrograms/g dt, with significant differences even between adjacent samples. Lobar differences were also observed, with a tendency of the right lobe to accumulate more copper than the left lobe. Histochemical analyses confirmed the uneven distribution of copper even at the acinar level. Copper was mainly stored in periportal hepatocytes (zone 1) and at the periphery of the regenerating nodules. Moreover, we observed some nodules with the majority of hepatocytes full of copper granules, adjacent to areas of parenchyma negative for copper stains. CONCLUSIONS Our data show that: 1) copper is unevenly distributed in Wilsons disease in the cirrhotic stage; 2) a lobar pattern of copper distribution is evident in this case, characterized by a higher copper concentration in the right lobe; 3) the observed lobar pattern is different from that described in the newborn liver, characterized by a higher copper content in the left compartment of the liver; 4) copper content determined in a small liver sample cannot be considered as absolutely representative of the mean hepatic copper concentration. From a practical point of view, our data show that sampling variability deserves more consideration in the diagnosis and in the monitoring of Wilsons disease. The use of hepatic copper concentration in monitoring the efficacy of the copper-chelating therapy may be unreliable, particularly in the cirrhotic stage, because of the patchy distribution of copper, as demonstrated in this study.

Morphogenesis and molecular mechanisms involved in human kidney development

The development of the human kidney is a complex process that requires interactions between epithelial and mesenchymal cells, eventually leading to the coordinated growth and differentiation of multiple highly specialized stromal, vascular, and epithelial cell types. The application of molecular biology and immunocytochemistry to the study of cell types involved in renal morphogenesis is leading to a better understanding of nephrogenesis, which requires a fine balance of many factors that can be disturbed by various prenatal events in humans. The aim of this paper is to review human kidney organogenesis, with particular emphasis on the sequence of morphological events, on the immunohistochemical peculiarities of nephron progenitor populations and on the molecular pathways regulating the process of mesenchymal to epithelial transition. Kidney development can be subdivided into five steps: (i) the primary ureteric bud (UB); (ii) the cap mesenchyme; (iii) the mesenchymal–epithelial transition; (iv) glomerulogenesis and tubulogenesis; (v) the interstitial cells. Complex correlations between morphological and molecular events from the origin of the UB and its branching to the metanephric mesenchyme, ending with the maturation of nephrons, have been reported in different animals, including mammals. Marked differences, observed among different species in the origin and the duration of nephrogenesis, suggest that morphological and molecular events may be different in different animal species and mammals. Further studies must be carried out in humans to verify at the morphological, immunohistochemical, and molecular levels if the outcome in humans parallels that previously described in other species. J. Cell. Physiol. 227: 1257–1268, 2012.

P16ink4a and HPV L1 Immunohistochemistry is Helpful for Estimating the Behavior of Low-grade Dysplastic Lesions of the Cervix Uteri

As only a minority of low-grade dysplastic lesions of the cervix uteri will eventually progress to carcinoma, predicting the behavior of these lesions could be of high value in clinical practice. The aim of the study was to evaluate p16ink4a and L1 as immunohistochemical markers of the biologic potentiality of low-grade dysplasia of the uterine cervix. The study included 38 conization specimens with coexisting cervical intraepithelial neoplasia grade 1 (CIN1) and 3 (CIN3) (group A) and 28 punch biopsies from women with CIN1 and proven spontaneous regression in the follow-up (group B). In group A, all CIN3 were p16ink4a positive (p16+) and L1 negative (L1−). The CIN1 of this group were p16+L1− and p16+L1+ in 68.42% and 31.57%, respectively. No other expression pattern was found in this group. In group B, the p16+L1−, p16+L1+, p16−L1+, and p16−L1− patterns were found in 3.57%, 25%, 14.29%, and 57.14%, respectively. Overall, 96.29% p16+L1− CIN1 were found in group A, whereas all the p16−L1+ and p16−L1− CIN1 were found in group B. A significant difference between staining pattern distributions of group A and B was observed (P<0.0001). The results of the study show that p16ink4a and L1 immunohistochemistry can be helpful for estimating the biologic potentiality of low-grade squamous cervical lesions. Particularly in cases in which the grade of the lesion is morphologically difficult to assess, the p16/L1 expression pattern could be useful for planning the clinical management of these women.

The Surprising Composition of the Salivary Proteome of Preterm Human Newborn

Saliva is a body fluid of a unique composition devoted to protect the mouth cavity and the digestive tract. Our high performance liquid chromatography (HPLC)-electrospray ionization-MS analysis of the acidic soluble fraction of saliva from preterm human newborn surprisingly revealed more than 40 protein masses often undetected in adult saliva. We were able to identify the following proteins: stefin A and stefin B, S100A7 (two isoforms), S100A8, S100A9 (four isoforms), S100A11, S100A12, small proline-rich protein 3 (two isoforms), lysozyme C, thymosins β4 and β10, antileukoproteinase, histone H1c, and α and γ globins. The average mass value reported in international data banks was often incongruent with our experimental results mostly because of post-translational modifications of the proteins, e.g. acetylation of the N-terminal residue. A quantitative label-free MS analysis showed protein levels altered in relation to the postconceptional age and suggested coordinate and hierarchical functions for these proteins during development. In summary, this study shows for the first time that analysis of these proteins in saliva of preterm newborns might represent a noninvasive way to obtain precious information of the molecular mechanisms of development of human fetal oral structures.

Uterine leiomyoma cytogenetics. II. Report of forty cases.

Chromosome analysis of 40 cultured uterine leiomyomas revealed the presence of clonal changes in 32.5% of them, confirming the cytogenetic heterogeneity within this type of tumor, mostly referable to a few cytogenetic subgroups. Preferential involvement of 12q14-15 and 14q23-24 bands in reciprocal and complex translocations was most commonly observed. Deletions of chromosome 7 and changes of chromosomes 1, 2, and to a lesser extent, chromosomes 19 and 22 were also found. Constitutional karyotype of patients bearing tumors with karyotypic abnormalities was examined. In one patient, two cells were found with t(12;14)(q14-15;q23-24) translocation and two with del(14)(q13q23-24). The latter rearrangement was also present as a clonal change in the tumor.

Familial cardiomyopathy, mental retardation and myopathy associated with desmin-type intermediate filaments

The clinical and morphological findings of a familial case affected by mental retardation, severe biventricular hypertrophic cardiomyopathy and vacuolar myopathy are reported. The phenotype of this patient is similar to that described by other authors, in which a lysosomal glycogen storage disease with normal acid maltase levels was suspected. However, in our case the vacuoles were stained by several antibodies directed against various sarcolemmal proteins, such as dystrophin and spectrin, and therefore, were not of lysosomal origin. Some of these vacuoles were clearly derived from the splitting of the fibres and invagination of the extracellular space; autophagic vacuoles were not observed. The accumulation of desmin-type, intermediate filaments was demonstrated on immunocytochemistry both in the skeletal and cardiac muscles. A brother of the propositus was also affected by mental retardation, severe cardiomyopathy and died suddenly at the age of 24 yr. A cardiomyopathy and mental subnormality were also present in other male cousins of the proband, while sudden death occurred in several females relatives, whose intelligence was normal. None of these latter individuals was available for further investigation. This report expands the spectrum of desmin associated myopathy and cardiomyopathy to include a familial condition with associated mental retardation.

Brain copper, iron, magnesium, zinc, calcium, sulfur and phosphorus storage in Wilson's disease.

PROJECT Wilsons disease (WD) is an inherited disorder of copper metabolism characterised by juvenile liver cirrhosis and by neurological symptoms. Copper levels in brain in WD have been reported to be 10 to 15 fold normal values, depending on the different brain regions. Being very few data on copper distribution in central nervous system in WD available, it seemed of interest to study the concentration of copper and of other trace elements (Zn, P, Mg, Ca, Fe and S) in the brain of a patient died for WD. PROCEDURE a 56 year old woman affected by WD was admitted to our hospital with signs of hepatic failure and died few days later. At autopsy, a brain slice extending from the left to the right hemisphere was divided in 28 samples. On each sample Copper, Iron, Magnesium, Phosphorus, Sulphur, Zinc and Calcium were determined by Induced Coupled Plasma Atomic Emission Spectroscopy. RESULTS the mean concentration of copper, ranging from 88 to 158 microg/g of dry tissue in all the brain specimens was higher than literature reference values, while that of the other tested elements was considerably lower. CONCLUSIONS 1) In the brain of WD patient examined the status of trace elements was extensively altered. Further studies are necessary to correlate the concentration of trace elements with pathological lesions and with clinical pictures. 2) The elements considered in our study showed an uneven distribution in different brain areas.