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Biomedical subjects

D Di Martino

Publications and source records attributed to D Di Martino.

At least 19 recordsLinked to original sources
PubMed2004

DNA extraction from blood determination membrane card test.

Among the several techniques applied in our laboratory, in order to establish human nature of blood specimens we perform an immunodiagnostic analysis through a specific membrane test card, which is usually utilized as a fast screening test for human haemoglobin in diagnostic checks. This test works with a double-step method based upon solubilization of the sample in a proper buffer and its migration on a membrane monoclonal and polyclonal antibodies specific against haemoglobin are linked to. The complexes haemoglobin-antibodies migrate through the membrane and are revealed by an immunoreactive line turning reddish-coloured to show that the reaction took place and the system works. As this test can recognize both the whole haemoglobin molecule and the degraded one, it is usually exploited in forensic sciences to detect kind and species of blood specimens related to forensic case works. However, as a consequence of the small amounts of blood in the samples collected from the crime scene we often cannot perform this kind of analysis in order to save the sample and be able to genotype it. Then, we investigated the possibility to purify DNA from the blood specimens already dissolved in the extraction buffer and perform STR typing on it with several methods and after different storage conditions and time.

Blood Specimen Collection↗
PubMed2004

Single sperm cell isolation by laser microdissection.

In 1996, Van Oorschot and Jones firstly reported in scientific correspondence that short tandem repeat (STR) profiles could be obtained from cells left on different objects. Since then, forensic scientists have focused their efforts in isolating single cells as it can be extremely helpful in solving case works where sexual violence was concerned. Laser microdissection is a micromanipulation procedure allowing to cut off precisely the cells of interest from tissue samples or smears by a laser beam fitted with an optical microscope. We have harvested single sperm cells by laser microdissection using a Leica AS LMD (Leica Microsystems, Germany); laser setting, pulse laser intensity and laser alignment as well as recovery of the specimen have been properly fitted to the samples we were dealing with. Different tissue preservation, fixation, histological staining (Papanicolau, Nuclear Fast Red-Picroindigocarmine) methods and number of harvested cells for each sample have been evaluated as well. Finally, the genotype of sperm cells has been determined by STR typing, evaluating the sensibility of this forensic technique according to instrumental and biological above-mentioned variables.

DNA↗
PubMed2004

Laser microdissection and DNA typing of cells from single hair follicles.

Isolation and identification of single cells from tissue samples or smears assume a great relevance in pathological and forensic applications; in this latter field, the possibility to identify a specific genetic profile can be obtained by short tandem repeat (STR) typing, allowing to achieve a scientific proof important in law courts. It is well known that DNA extraction may be performed from several tissue fragments, blood traces, spermatozoa as well as telogen hair. However, in the last case, few follicle cells are coupled to a great amount of keratin reducing the efficiency of DNA amplification. Recently, the introduction of laser microdissection technique has greatly improved the capability to select single cells without any cross-contamination. In the present report, we have performed a laser microdissection using a Leica AS LMD (Leica Microsystems, Germany), utilized on cutting the telogen hair in order to exclusively collect the lower part of the follicle and reduce keratin contamination. In this way we can accurately extract an adequate amount of DNA, successfully typed by STR profile.

DNA↗
PubMed2004

Experimental procedures comparing the activity of different Taq polymerases.

Forensic investigations involve several scientific branches among which biological analyses are much more frequently requested as a consequence of their importance and great versatility towards most of the traces found on the crime scene. Biological analyses are lead in subsequent steps: extraction, amplification and STR typing of the specimens collected on the crime scene. All of these techniques have been modified from original protocols according to the kind of sample to process. A critical point in our analysis is trying to amplify small amounts of DNA extracted from decomposed tissues or objects, small biological traces have been left on, with high fidelity and account. That's why we have decided to settle on an experimental procedure aimed to find the best DNA polymerase according to our purposes. We have tested different Taq polymerases on the same known DNA sample at several dilutions and have compared quality and amount of amplified DNA in order to appreciate the amplifying capability of each enzyme. These data have been analyzed as a function of the technical properties of each engineered Taq polymerase and results are shown in details.

DNA↗
PubMed2004

A novel approach in personal identification from tissue samples undergone different processes through STR typing.

Short tandem repeats (STRs) or microsatellites have been recognized worldwide as a powerful tool for human identification. They have become widely used in human identification especially in criminal cases and mass disasters. Police departments are often interested in cases where tissues are already decomposed and only do bones remain to let them perform laboratory analyses. Bone is the most resistant tissue in animal body to time depending degradation and putrefaction, but it is often hard to extract DNA from it because of its highly mineralized structure, which makes DNA extraction and/or amplification hard to carry out. We have performed human nuclear DNA extraction and STR typing in three different cases, on bones and bone fragments from long time dead persons found buried, in the sea, almost completely burnt and whose tissues were already decomposed. We report these caseworks as we would like to show how forensic scientists are improving their skill in identifying people whose corps have undergone several kinds of processes, even independently on the time passed and the level of putrefaction of their tissues.

Bone and Bones↗
PubMed2000

Detection of T cell receptor delta gene rearrangements in childhood B and T lineage acute lymphoblastic leukaemia by southern blot and PCR: technical comparison of two methods of analysis.

Molecular analysis of antigen receptor genes (Ig and TCR) has been useful for clonal studies in acute lymphoblastic leukaemia (ALL) patients. Rearrangements of these genes can be used to track the persistence of the leukaemic clone during the therapy. The purpose of our study was to analyse the percentage and the pattern of the rearrangements at the TCR D locus in a series of ALL patients, comparing the results obtained by Southern blot and PCR. Genomic DNA was extracted from mononuclear BM cells of 40 paediatric ALL cases, digested with different restriction enzymes and hybridized to TCRDJ1 probe to study the TCR delta locus. Amplification of the rearranged TCR delta genes was performed by PCR to define the gene segments involved. The junctional region was deduced from the sequence to obtain patient-specific primers. Among the 31 B lineage ALL samples, one or two TCR delta alleles proved to be rearranged in 53% of cases. Two different types of rearrangements were chiefly detected: Vdelta2Ddelta3 and Ddelta2Ddelta3. In T-ALL patients, the predominant rearrangement involved the Vdelta1 and the Jdelta1 gene segments.

Adolescent↗
PubMed2000

The expression of metalloproteinase-2, -9, and -14 and of tissue inhibitors-1 and -2 is developmentally modulated during osteogenesis in vitro, the mature osteoblastic phenotype expressing metalloproteinase-14.

During osteogenesis, in vitro, of tibial-derived rat osteoblasts (ROB) and derived clones, changes occur in the interactions of mature osteoblasts with the endogenous extracellular matrix (ECM) and these culminate in the formation of tridimensional nodules, which become sites of mineral deposition. We investigated if these changes might be mediated by remodeling of ECM, and we focused our study on the neutral metalloproteinases (MMPs), known agents of matrix remodeling, and on their tissue inhibitors (TIMPs). We report that during in vitro differentiation, osteoblasts express the secreted MMP-2 and -9 and the membrane gelatinase MMP-14. These, along with the tissue inhibitors TIMP-1 and -2, are developmentally regulated according to the maturation stage of osteoblasts. Their levels change in a similar association with osteoblast phenotypic maturation in different populations of ROB, which take different times to complete osteogenesis in vitro. MMP-14 expression coincides in both cell populations with the mature osteoblastic phenotype and is localized in the cells forming nodules. MMP-2 and -9 are expressed diffusely in the osteoblast population. Developmentally associated changes in the activation of MMP-2 are detected, associated in their timing with the expression of MMP-14 in both populations of ROB, and MMP-14 activates pro-MMP-2 in vitro. Expression of messenger RNAs (mRNAs) for the three MMPs increases up to the time of nodule formation. At this stage, TIMP-1 mRNA levels are lowest. TIMP-2 mRNA decreases throughout osteogenesis. In situ hybridization in 7-day-old rat tibias shows the strongest expression of MMP-14 among osteogenic cells, in lining osteoblasts on the newly formed trabeculae under the growth plate, and on the endosteal surface of cortical bone. Our data support the concept that the developmentally regulated expression of MMP-14 triggers localized proteolysis within the osteogenic population, concomitant in vitro to nodule formation.

Animals↗
PubMed2000

Late Epstein-Barr virus infection of a hepatosplenic gamma delta T-cell lymphoma arising in a kidney transplant recipient.

BACKGROUND AND OBJECTIVE: gd T-cell lymphomas are only exceptionally observed in transplanted patients. Aim of this study was the detailed characterization of one such case. DESIGN AND METHODS: The patient developed spontaneous splenic rupture six years after kidney transplantation. The splenic red pulp was infiltrated by medium-sized and large lymphoid cells with two or more nucleoli. At autopsy, similar lymphoid cells infiltrated the hepatic sinusoids. Histologic, immunologic and molecular studies were carried out. RESULTS: By immunohistochemistry, the atypical lymphoid cells were found to express CD3, CD45 and CD43, indicating their T-lineage origin. Approximately 99% of spleen mononuclear cells (MNC) were CD3(+), gammadelta TcR+, CD4-, CD8-, alphabeta TcR-. A clonal gammadelta TcR rearrangement (Vgamma1-Jgamma1.3/2.3-Cgamma2; Vdelta1-Ddelta2-Jdelta1) was detected. The final diagnosis was peripheral T-cell lymphoma, hepato-splenic gammadelta-type. EBV infection of spleen MNC was documented by molecular studies. However, in situ hybridization for EBER-1 (EBV-RNA) showed that only a minority of malignant lymphoid cells (5-7%) were EBV-infected. INTERPRETATION AND CONCLUSIONS: It is concluded that EBV infection was as a late event involving an already transformed gd T-cell clone.

Adult↗
PubMed1999

Exocrine pancreatic function and fat malabsorption in human immunodeficiency virus-infected patients.

BACKGROUND: Nutrients malabsorption frequently occurs in human immunodeficiency virus (HIV)-infected patients, but very few studies have investigated exocrine pancreatic digestive capacity in these patients. We therefore evaluated the frequency of exocrine pancreatic impairment and its eventual relation with fat malabsorption in HIV-infected patients. METHODS: Thirty-five HIV-infected patients (30 male, 5 female: mean age +/- standard deviation, 33.6 +/- 7.2 years) and 51 sex- and age-matched controls without gastroenterologic diseases were studied. In all subjects fecal elastase 1 (EL-1) was assayed, and fecal fat excretion was evaluated with the steatocrit test. RESULTS: Nineteen of 35 (54%) HIV-infected patients showed subnormal EL-1 values, whereas all the controls had normal values; furthermore, EL-1 values were significantly lower in patients than in controls: mean (95% confidence intervals), 207 ( 164-251 ) microg/g versus 312 (291-332) microg/g (P < 0.0001). Increased fecal fat excretion was observed in almost all (25 of 35) HIV-infected patients, and an inverse but not significant correlation was found between fecal EL-1 and steatocrit values. No association was found between reduced fecal EL-1 and the severity of HIV disease or nutritional and immunologic status. Opportunistic infections and drug administration had no influence on EL-1 concentrations in stools. CONCLUSIONS: Reduced exopancreatic function is frequent in HIV-infected patients but does not seem to be a major factor contributing to fat malabsorption.

Adult↗
PubMed1998

Rapid detection of gammaT cell receptor gene rearrangements in acute lymphoblastic leukemia by electrophoresis and silver staining: implications for detection of minimal residual disease.

Minimal residual disease (MRD) in acute lymphoblastic leukemia (ALL) was studied using polymerase chain reaction (PCR). GammaT cell receptor (TCRG) genes are ideal targets for PCR-based detection of MRD due to their molecular characteristics. Polyacrylamide gel electrophoresis (PAGE) analysis of PCR products followed by silver staining was performed for 72 children with ALL at the onset of disease. Silver staining is an effective technique to detect gene rearrangements without the use of ethidium bromide. Moreover, this method may show heteroduplex bands of a clonal nature when both TCRG alleles are rearranged. PCR products subjected to a rapid staining protocol were recovered from the gel, reamplified by a second PCR and directly sequenced. After sequencing, we identified the junctional region and obtained patient-specific probes. In more than half of the patients we detected TCRG rearrangements that were used as molecular markers for residual disease.

Child↗
PubMed1998

Pancreatic dysfunction and its association with fat malabsorption in HIV infected children.

BACKGROUND: Nutrient malabsorption frequently occurs in HIV infected children, but very few studies have investigated exocrine pancreatic digestive capacity in these cases. AIMS: To investigate pancreatic function in HIV infected children and to determine whether faecal fat loss, a prominent feature of intestinal dysfunction, is associated with pancreatic dysfunction. PATIENTS: Forty seven children with HIV infection without apparent pancreatic disease and 45 sex and age matched healthy controls. METHODS: Pancreatic function was evaluated by measuring elastase 1 concentration and chymotrypsin activity in stools by ELISA and colorimetric methods, respectively. Intestinal function was evaluated by measuring fat and protein loss by the steatocrit method and by faecal alpha1 antitrypsin concentration. RESULTS: 14 (30%) had abnormal pancreatic function tests: seven had isolated elastase activity deficiency, three isolated chymotrypsin deficiency, and four pancreatic deficiencies in both enzymes. Patient enzyme values were significantly lower than those of controls. Low faecal pancreatic enzymes were not associated with symptoms. Twelve children had steatorrhoea and four had increased alpha1 antitrypsin. Steatorrhoea was significantly associated with reduced faecal pancreatic enzymes. There was a significant negative correlation between elastase 1 concentration and steatocrit. Children with pathological faecal elastase 1 or chymotrypsin values did not differ from the other HIV infected children with respect to nutritional and immunological status, stage of HIV disease, presence of opportunistic infections, or drug administration. CONCLUSIONS: Abnormal pancreatic function tests are a frequent feature of paediatric HIV infection; this condition is associated with steatorrhoea, which probably contributes to the disease.

Adolescent↗
PubMed1997

Serum HCV-RNA and liver histologic findings in patients with long-term normal transaminases.

In this study we aimed to correlate liver histology and the presence of hepatitis C virus (HCV) viremia, genotype, and quantity of HCV genome in 19 positive and 11 RIBA II indeterminate patients presenting persistently normal ALT values over 24 months before biopsy. In addition, after biopsy serum ALT values were monitored monthly for a mean follow-up period of 24.8 months, after which patients were reevaluated for RIBA II and the presence of viremia. Sixteen patients (53%) were serum HCV-RNA-positive; 13 of them (68%) were confirmed positive and 3 (27%) indeterminate on RIBA II. Histology of the HCV-RNA-positive patients showed eight cases of CPH (one case of genotype 1a; four cases type 1b; three cases type 2), six cases of CAH (three cases type 1b, three cases type 2), one case of CLH (type not determined), and one case of normal liver (NL) (type 1b). Histology of the HCV-RNA-negative patients showed four cases of CPH, one case of CAH, two cases of CLH, and seven cases of NL. During the follow-up period nine patients (30%) presented slight increases in ALT values (< 2 x N), and in particular, flares of ALT were observed four times in the CAH and five times in the CPH patients, who were all viremic, but never in the NL subjects. These results indicate that subjects positive on RIBA II, but with persistently normal ALT values, had a high probability of being serum HCV-RNA-positive and that almost all these viremic subjects presented histologic signs of liver disease. In contrast, RIBA II indeterminate subjects had a moderate probability of being HCV-RNA-positive, but a number of these may present signs of liver disease. In both cases there was no association with genotype or HCV-RNA serum levels. The other nonviremic cases included subjects with hepatic changes going toward resolution or with normal liver in whom hepatic biopsy can be avoided. Only one case was a true carrier since he was viremic with normal liver and persistently normal ALT values.

Adult↗
PubMed1997

Influence of haemodialysis on lipase activity.

Our aim was to determine whether the increase in serum pancreatic lipase values, reported in patients with chronic renal failure maintained on haemodialysis, is the result of haemoconcentration by fluid removal during dialysis, or whether it is due to lipase stimulation by endothelial lipoprotein lipase, induced by the heparin used as an anticoagulant. We therefore compared the increases in serum lipase, when heparin was used, with those observed when this was replaced by the antithrombotic agent, defibrotide, which has no effect on lipoprotein lipase. In addition, in order to determine the effects of haemoconcentration, variations in total protein concentration and haematocrit values were determined on the same samples, both before and after dialysis. The results showed a statistically significant post-dialysis increase in lipase only when heparin was used (p < 0.03). There was also a mean percentage post-dialysis increase of 16.2% in total protein (p < 0.0001) and 15.5% in haematocrit (p < 0.0001), due to fluid removal. No significant correlation in percentage increases was found between lipase vs total protein or haematocrit values. These findings suggest that heparin-induced lipoprotein lipase stimulation is the principal cause of the post-dialysis increase in pancreatic lipase, and that fluid removal during dialysis makes only a minor contribution to this increase.

Adult↗
PubMed1994

Pancreatic insufficiency in celiac disease is not dependent on nutritional status.

To determine the relationship between pancreatic secretory capacity and nutritional status in celiac patients, we studied 52 patients with celiac disease (24 males, 28 females; age range 6-36 months) and 30 healthy control subjects (14 males, 16 females; age range 6-42 months). A secretin-cerulein test was performed on all patients, and levels of serum albumin and plasma fibronectin were assayed. In addition, weight/height ratios were calculated in the celiacs, who were then divided into three groups on this basis, as follows: celiacs with weight/height ratio < or = 3rd percentile; those with weight/height ratio between the 4th and 10th percentiles; and those with weight/height ratio > 10th percentile. There was no significant difference in the duodenal output of chymotrypsin, phospholipase and lipase between these groups. When the total celiac group was compared to control subjects, only lipase levels were significantly lower (P < 0.009). However, subnormal values in one or more pancreatic enzymes were observed in 15/52 celiacs (29%). A residual enzyme activity < 10% of normal secretory capacity, was also found in 4/52 patients. There was no correlation between the output of the various pancreatic enzymes and levels of albumin, fibronectin, and weight/height ratios in the patients. Furthermore, there was no difference in weight/height ratios and levels of albumin and fibronectin between the celiac subjects with pancreatic deficiency and those with normal pancreatic function. We conclude that a mild/moderate pancreatic insufficiency is quite frequent in celiacs, but that it may be completely independent of nutritional status; further studies are therefore required to shed light on its pathogenesis.

Biopsy↗
PubMed1993

[Plasma fibronectin in chronic liver diseases].

This study was carried out to evaluated the role of the fibronectin (FN) in chronic liver diseases. For these reasons FN plasmatic concentration was assayed in patient with different degrees of chronic liver disease. For these reasons FN plasmatic concentration was assayed in patient with different degrees of chronic liver disease; the correlation between FN and the most common parameters of liver function was also evaluated. Moreover we also correlated FN plasma levels with laminin and the N-terminale peptide of type III procollagen, serum levels, that are through to be markers of fibrogenesis. 172 patients were studied: twenty-one patients suffering from chronic persistent hepatitis (CPH), 45 from chronic active hepatitis (CAH) and 106 from liver cirrhosis (LC). Last patients were also divided according the Child-Pugh's classification. Control group was composed of 74 healthy blood donors. Significant reduction of plasmatic levels of FN was found in the LC groups in comparison with control group (p < 0.0001) and also with CPH group (p < 0.01) and with CAH group (p < 0.0001). Lower values of FN were found in the LC group at advanced stage (Child-Pugh's B and C classes). In the group of CAH significant correlations with the parameters of cholestasis (GGT, APh, Tot. Bil. p < 0.005) were found, while in the group of LC significant correlations both with the parameters of synthesis (Alb. and Protr. time p < 0.01) and necrosis (AST/ALT p < 0.001). A negative correlation was also found between FN and spleen volume (p < 0.05). No correlation between FN and the parameters of fibrosis was found.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Pancreatic enzymes in chronic renal failure and transplant patients.

The aim of the present study was to determine the frequency and degree of elevated serum levels of Total Amylase (TA), Pancreatic Amylase (PA), and Lipase (L) activity in patients with chronic renal failure (CRF) on conservative therapy; CRF on periodical hemodialysis (HD); in renal transplant (RT) and in a control Group (C). Mean values were significantly higher in all groups than Group C for TA (p < 0.005), PA (p < 0.0001) and L (p < 0.0001). A statistically significant correlation was found between TA and L vs creatininemia values in CRF patients, but only up to a certain level (creatininemia < 6 mg %) (p < 0.03 and p < 0.05), above which there was no correlation. The enzyme most frequently over the maximum normal limit was PA, both in the total CRF group (51%), in the hemodialysis patients (65%), and in the RT patients (55%); but only a few patients had values two times higher than the normal limits: 15% in the total CRF, 14% is the hemodialysis, and 10% in the RT groups, respectively. These results suggest that the increase in serum pancreatic enzyme during chronic renal pathology is slight but frequently occurs. It is possible that in these patients together with the renal excretion impairment there could also be some subclinical pancreatic damage; its genesis could also depend on the pharmacological treatment used (diuretics, immunosuppressive drugs) commonly adopted in these pathologies.

Adult↗
PubMed1992

Expression of histone H3 cell cycle-related gene, vimentin and MYC genes in pediatric brain tumors. A preliminary analysis showing the different malignant cell growth potential.

Eleven pediatric brain tumors were studied for the histone H3, Vimentin and MYC gene expression. H3, an S phase cell cycle-related gene (ccr), was found prevalently expressed in tumors with a high mitotic index (MI). Vimentin gene, which contributes to maintaining the cell structure but is also demonstrated to be an early responder gene to growth stimulation was found variously expressed. The different expression of Vimentin gene in the examined samples suggests the active proliferation of the tumor cells. Analysis of MYC gene expression was found increased only in a mesenchymal chondrosarcoma while in other samples MYC mRNA was undetectable. Medulloblastoma, chondrosarcoma, and choroid plexus carcinoma have high S phase H3 gene expression associated with a high MI. Differently an astrocytoma shows a low MI associated with high H3 gene expression. This first preliminary report of H3, Vimentin and MYC gene expression in brain tumors demonstrates that malignant cells are characterized by a different gene expression and different growth potentials.

Adolescent↗