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Biomedical subjects

M Colombo

Publications and source records attributed to M Colombo.

At least 55 records · Page 3Linked to original sources
PubMed1999

Identification of a novel molecular partner of the E2A gene in childhood leukemia.

The 'promiscuous' E2A gene, at 19p13.3, is fused with two different molecular partners, PBX1 and HLF, following two chromosome translocations recurrent in childhood pre-B ALL. We have identified a novel gene, FB1, by virtue of its fusion with E2A and by a combination of molecular techniques. FB1 was localized on 19q13.4, suggesting that the novel chimera originated by a cryptic rearrangement of chromosome 19. Two FB1 transcripts, of 1.2 kb and 1.1 kb, are differentially expressed at low level in a variety of human tissues, including hemopoietic cell lines from different lineages. Accordingly, FB1 cDNA displays high homology with a number of cDNA clones from different human tissues. High homology was found also with cDNA clones from mouse and rat, suggesting that the sequence might be conserved at least among mammals. The function of the putative FB1 protein, however, is currently unknown as database sequence comparisons have failed to reveal strong homology with known proteins. The E2A/FB1 fusion appears to be a recurrent feature of pre-B ALLs, suggesting that it might have a role in the development and/or progression of leukemogenesis.

Adenovirus E2 Proteins↗
PubMed1999

Serum levels of hepatitis C virus RNA predict non-response to interferon therapy: comparison of two commercial assays.

We compared two commercial assays for quantification of serum hepatitis C virus (HCV) RNA to investigate whether pretreatment levels of serum HCV RNA could predict the outcome of interferon (IFN) therapy. The Amplicor HCV Monitor test is based on a single, combined reverse transcription and amplification reaction carried out by the Tth DNA polymerase using specific primers for the 5' untranslated (UTR) region. The Quantiplex HCV RNA 2.0 assay is based on specific hybridization of viral RNA by synthetic oligonucleotides complementary to the 5'-UTR and core regions of the genome, allowing equal quantification of the six major genotypes. Receiver-operating characteristic (ROC) analysis was employed to identify the best cut-off value (predicting patients who were non-responsive to treatment) with corresponding sensitivity and specificity values. Logistic regression analysis was performed using these cut-off values. We studied 133 consecutive patients with chronic hepatitis C enrolled in a prospecsustained responders was 5322 copies ml-1 by the Monitor test and less than 0.2 million equivalents ml-1 (MEq ml-1) by the Quantiplex assay; for the 115 non-responders/relapsers, the median viraemia was 83,125 copies ml-1 and 1.128 MEq ml-1 for the Monitor test and Quantiplex assay, respectively. Spearman's rank test gave a correlation of 0.63 between assays. The best predicting cut-off values were 22,134 copies ml-1 for the Monitor test and 0.330 MEq ml-1 for the Quantiplex assay; their respective sensitivities and specificities were 72% and 75% for Monitor and 67% and 83% for Quantiplex. By logistic regression analysis, the age and gender-adjusted odds ratios of high vs low HCV RNA levels, defining the risk of non-response, were 10.6 (CI 3.1-35.7) for Monitor and 14.3 (CI 4.3-47.3) for Quantiplex. The two assays had comparable sensitivity for serum HCV RNA but they identified different predictive cut-offs for non-response to therapy.

Adult↗
PubMed1999

Hepatitis C virus and hepatocellular carcinoma.

The sequential development of cirrhosis and hepatocellular carcinoma (HCC) in patients with transfusion-associated hepatitis was a clue leading to the identification of hepatitis C virus (HCV) as a risk factor for HCC. The incidence of HCV-related liver cancer is increasing in many developed countries: tumours arise in older patients, are almost invariably associated with cirrhosis and often have a less aggressive course than is seen in HCC related to other aetiological factors. Most HCCs grow as a single hepatic nodule for several years before generating satellite or distant tumour nodules. Tumour progression and hepatic failure are the leading causes of death. HCV might promote cancer through cirrhosis, which is per se an important risk factor for this tumour. HCV might also have oncogenic properties by interacting with cellular genes that regulate cell growth and differentiation. The primary prevention of HCC through vaccination against HCV is not yet available. The treatment of patients with chronic hepatitis C with interferon might attenuate the risk of HCC.

Animals↗
PubMed1999

Hepatitis C virus and hepatocellular carcinoma.

Hepatitis C virus (HCV) is pathogenetically involved in many cases of hepatocellular carcinoma (HCC) worldwide. HCV-related HCC is on the rise in many developed countries as a consequence of past infections with HCV. The time lag between HCV infection and cancer development is several decades. HCV-related tumors arise in older patients, are almost invariably associated with cirrhosis, and often have a less aggressive course than HCC related to other etiologic factors. In most patients, HCC grows as a single hepatic node for years before generating satellite or distant tumor nodes. However, there are tumors that originate as multifocal disease. Tumor progression and hepatic failure are the leading causes of death in most patients. HCV has been almost invariably detected in tumor tissue of anti-HCV patients with HCV, but it is not clear whether the virus promotes cancer through chronic hepatocellular inflammation, which is per se an important risk factor for HCC, or has a direct role in liver carcinogenesis. No reverse transcriptase activity has been found in infected livers, but there are data suggesting that HCV has oncogenic properties, because its interacts with cellular genes regulating cell growth and differentiation.

Carcinoma, Hepatocellular↗
PubMed1999

Fluctuations of radial artery distensibility throughout the menstrual cycle.

Estrogen administration has a number of favorable cardiovascular effects, and recent evidence suggests that these include an increase in arterial distensibility. Whether this is also the case for the physiological changes in estrogen production during the menstrual cycle has never been determined, however. In 21 premenopausal healthy women, we continuously measured radial artery diameter and blood pressure by an echo-tracking device and a beat-to-beat finger device, respectively. Arterial distensibility was calculated as distensibility/blood pressure curve. The measurements were made during the follicular, ovulatory, and luteal phases of the menstrual cycle. As expected, compared with the follicular phase, plasma estradiol, follicle-stimulating hormone, luteinizing hormone, and prolactin were increased in the ovulatory phase, whereas progesterone was increased in the luteal phase, together with antidiuretic hormone. Radial artery distensibility was increased in the ovulatory and reduced in the luteal phase, the changes being independent of the small, concomitant blood pressure changes. The arterial wall stiffening seen in the luteal phase was associated with a reduction in the flow-dependent endothelial dilatation of the radial artery as assessed by the hyperemia after short-term ischemia of the hand. Thus, the natural menstrual cycle is characterized by alterations in radial artery distensibility. The mechanisms responsible for this phenomenon remain to be clarified. It is possible, however, that the greater arterial distensibility of the ovulatory phase is due to an estrogen-dependent reduction in vascular smooth muscle tone, whereas the arterial stiffening of the luteal phase depends on vascular smooth muscle contraction due to more complex hormonal phenomena, ie, an endothelial impairment due to estrogen reduction but also to an increase in progesterone and antidiuretic hormone levels.

Adult↗
PubMed1999

Uterine rupture after hysteroscopic metroplasty and labor induction. A case report.

BACKGROUND: Hysteroscopic metroplasty has become the method of choice for the treatment of uterine septa. Uterine perforation has been reported in about 1% of surgical hysteroscopic procedures. Ultrasound allows the detection of uterine lesions. CASE: A woman who conceived after complicated hysteroscopic metroplasty underwent emergency cesarean section because of uterine rupture during labor induced with prostaglandins (PGE2). An ultrasound scan performed two years later revealed a uterine lesion that corresponded to the myometrial tear reported at cesarean section. CONCLUSION: Complicated hysteroscopic metroplasty may promote acute uterine rupture during pregnancy and labor. Ultrasound is a useful tool for the detection of uterine lesions. If adequately considered, it might have allowed more rational management of labor in this case. PGE2 should never be used for induction of labor after complicated metroplasty.

Adult↗
PubMed1999

[Practice guidelines to manage children admitted in a general pediatric department with very mild or mild acute infective diarrhea].

A clinical-anamnestic card is proposed to gather the main minimal parameters which allow to monitor the course of children with severe or mild acute infective diarrhoea admitted to a pediatric department. This method has been verified through a back-evaluation of the data collected in our clinical-anamnestic cards throughout a period of seven months, and found it useful and appropriate. This case-record includes very mild or mild acute infective diarrhoea (corresponding to a loss lower than 10% of total body weight) in pediatric age children hospitalized in a general pediatric department. The clinical-anamnestic card is divided into five parts coinciding to five different clinical stages of the disease; during each stage, the essential anamnestic and/or clinical data necessary to a correct medical and nursing approach to the children affected with infective acute diarrhoea are recorded. The use of this card is also a good way to engage physicians, nurses and children's parents too, to pay attention to the substantial factors necessary for a correct management of the disease. The evaluation of these clinical-anamnestic cards led to the following general conclusions:--to keep body weight unmodified from the day of admission to the day of discharge--to use very seldom milk without lactose--to keep children on a very short term diet in order to quickly restore intestinal function, to increase body weight and to discharge children in few days.

Acute Disease↗
PubMed1998

High prevalence of serum cryoglobulins in multitransfused hemophilic patients with chronic hepatitis C.

The prevalence, clinical relevance, and risk factors of serum cryoglobulins in hemophilic patients with chronic hepatitis C virus (HCV) infection are unknown. We studied 135 consecutive hemophilic patients (median age, 31 years; range, 10 to 69 years) with chronic hepatitis C, exposed to the virus for 10 to 41 years. A total of 67 patients were coinfected with the human immunodeficiency virus (HIV), and 3 (2%) had signs of cirrhosis. Serum samples were tested for the presence of cryoglobulins, hepatitis B virus (HBV) markers, including HBV-DNA by hybridization assay, and antibody to HCV by enzyme immunoassay (EIA). Serum HCV-RNA was tested by polymerase chain reaction and typed with a hybridization technique. Samples were also tested for antitissue antibodies, immunoglobulins, rheumatoid factor, and C3 and C4 proteins of complement. Forty-two hemophiliacs (31%) circulated cryoglobulins (median levels, 166 mg/L; range, 66 to 480) predominantly type III (62%; and 29% type II). None of the patients had clinical signs or symptoms of systemic vasculitis. Cryoglobulinemic patients had more often serum HCV-RNA (95% v 80%, P < .05), rheumatoid factor (20% v 6%, P < .05), higher levels of IgG (2,354 +/- 682 mg/dL v 1,928 +/- 557 mg/dL, P < .0005) and IgM (323 +/- 226 mg/dL v 244 +/- 243 mg/dL, P < .05), and lower levels of serum C4 (19 +/- 8 mg/dL v 24 +/- 8 mg/dL, P < .05) than patients without cryoglobulins. The risk of producing cryoglobulins was greater for 114 patients circulating HCV-RNA than for 21 nonviremic patients (odds ratio [OR] = 4.9, 95% confidence interval [CI] = 1.1 to 22.0) and for the 31 patients with longer exposure to HCV (more than 26 years) than for the 24 patients with shorter (17 years or less) exposure (OR = 4.4 95% CI = 1.1 to 18.0). In conclusion a large number of multitransfused hemophiliacs with chronic HCV infection circulated serum cryoglobulins but none had clinical signs or symptoms of vasculitis. The risk of developing cryoglobulins parallels the duration of exposure to HCV.

Adolescent↗
PubMed1998

Body weight reduction, sympathetic nerve traffic, and arterial baroreflex in obese normotensive humans.

BACKGROUND: Previous studies have shown that sympathetic cardiovascular outflow is increased in obese normotensive subjects and that this increase is associated with a baroreflex impairment. The purpose of this study was to determine whether these abnormalities are irreversible or can be favorably affected by body weight reduction. METHODS AND RESULTS: In 20 obese normotensive subjects (age, 31.3+/-1.7 years; body mass index, 37.6+/-0.9 kg/m2, mean+/-SEM), we measured beat-to-beat arterial blood pressure (Finapres technique), heart rate (ECG), postganglionic muscle sympathetic nerve activity (microneurography at a peroneal nerve), and venous plasma norepinephrine (high-performance liquid chromatography) at rest and during baroreceptor stimulation and deactivation induced by increases and reductions of blood pressure via stepwise intravenous infusions of phenylephrine and nitroprusside. Measurements were repeated in 10 subjects after a 16-week hypocaloric diet with normal sodium content (4600 to 5000 J and 210 mmol NaCl/d) and in the remaining 10 subjects after a 16-week observation period without any reduction in the caloric intake. The hypocaloric diet significantly reduced body mass index, slightly reduced blood pressure, and caused a significant and marked decrease in both muscle sympathetic nerve activity (from 50.0+/-5.1 to 32.9+/-4.6 bursts per 100 heart beats, P<.01) and plasma norepinephrine (from 356.2+/-43 to 258.4+/-29 pg/mL, P<.05). This was associated with a significant improvement in the sensitivity of the baroreceptor heart rate (+71.5 +/- 11%, P<.01) and muscle sympathetic nerve activity (+124.5 +/- 22%, P<.001) reflex. Total body glucose uptake also increased significantly (+60.8 +/- 12.0%, P<.05), indicating an increase in insulin sensitivity. All variables remained unchanged in subjects not undergoing caloric restriction. CONCLUSIONS: In obese normotensive subjects, a reduction in body weight induced by a hypocaloric diet with normal sodium content exerts a marked reduction in sympathetic activity owing to central sympathoinhibition. This can be due to the consequences of an increased insulin sensitivity but also to a restoration of the baroreflex control of the cardiovascular system with weight loss.

Adult↗
PubMed1998

A prospective multicenter study of hepatocellular carcinoma in italian hemophiliacs with chronic hepatitis C. The Study Group of the Association of Italian Hemophilia Centers.

To assess the risk factors, natural history, and eligibility for curative treatment of early-detected hepatocellular carcinoma (HCC), 385 hemophiliacs who were treated with blood or plasma derivates for at least 10 years and had persistently elevated aminotransferase values underwent an annual screening with an abdominal ultrasound examination and measurement of the serum alpha-fetoprotein (AFP) level. Of these, 355 had serum antibody to hepatitis C virus (anti-HCV), 29 had anti-HCV and hepatitis B surface antigen (HBsAg), and one had HBsAg alone; 141 had serum antibody to human immunodeficiency virus (anti-HIV). During 48 months of follow-up study, six patients developed HCC. All HCC patients had a HCV-related cirrhosis and had been exposed to HCV risk at a median age of 40 years. All patients had a multicentric tumor, which was not eligible for curative treatment. Univariate analysis showed age, cirrhosis, and baseline AFP levels to be significantly associated with an increased risk of HCC. By multivariate analysis, the risk of HCC was infinite in patients with cirrhosis, 31.0 for those with baseline AFP higher than 11 ng/mL, and 17.9 for those more than 45 years of age. In conclusion, the risk of cancer was greater for patients infected later in life, particularly those with cirrhosis and high AFP. Annual screening of hemophiliacs with ultrasound and AFP fails to identify potentially curable tumors because the diagnosis is made at a late stage of the disease.

Adolescent↗
PubMed1998

Synthesis and anticonvulsant activity of a new class of 2-[(arylalky)amino]alkanamide derivatives.

Although most epilepsies are adequately treated by conventional antiepileptic therapy, there remains an unfulfilled need for safer and more effective anticonvulsant agents. Starting from milacemide, a weak anticonvulsant, and trying to elucidate its mechanism of action, we discovered a structurally novel class of potent and preclinically safe anticonvulsants. Here we report the structure-activity relationship (SAR) study within this series of compounds. Different parts of the structural lead 2-[[4-(3-chlorobenzoxy)benzyl]amino]acetamide (6) were thus varied (Figure 1), and many potent anticonvulsants were found. As an outcome of this study, 57 ((S)-2-[[4-(3-fluorobenzoxy)benzyl]amino]propanamide methanesulfonate, PNU-151774E) emerged as a promising candidate for further development for its potent anticonvulsant activity and outstanding therapeutic indexes (TIs) in different animal tests.

Alanine↗
PubMed1998

The role of hepatitis C virus in hepatocellular carcinoma.

The sequential development of cirrhosis and hepatocellular carcinoma (HCC) in patients with post-transfusion hepatitis was a clue that led to the identification of hepatitis C virus (HCV) as a risk factor for HCC. The average time lag between transfusion-associated infection and cancer development was 30 years, with a range of 15-45 years. Using the polymerase chain reaction (PCR) technique, HCV-RNA has been almost invariably detected in serum and tumor tissue of anti-HCV-seropositive patients with HCC In many patients, HCV-RNA was found to belong to the more pathogenic type 1b. However, it is unlikely that HCV plays a direct role in liver tumorigenesis, since no reverse transcriptase activity has been found in infected livers. One current opinion is that HCV may promote cancer through cirrhosis, which is per se an important risk factor for this tumor: almost all patients with HCC have cirrhosis and up to 30% of them have coexisting serological evidence of hepatitis B virus (HBV) or alcohol abuse, further supporting the idea that both HCC and cirrhosis might result from the interplay of several risk factors. However, there are also data suggesting that HCV may interact with cellular genes regulating cell growth and differentiation independently of the onset of cirrhosis.

Carcinoma, Hepatocellular↗
PubMed1998

Sacrospinous ligament fixation and modified McCall culdoplasty during vaginal hysterectomy for advanced uterovaginal prolapse.

OBJECTIVE: Our purpose was to compare anatomic and functional results of 2 procedures performed at vaginal hysterectomy for vaginal vault suspension in patients with advanced uterovaginal prolapse. STUDY DESIGN: A retrospective case-control study was designed comparing 62 patients who underwent sacrospinous ligament fixation and 62 members of a matched control group who underwent modified McCall culdoplasty during vaginal hysterectomy and reconstructive pelvic surgery. The 62 pairs were matched for grade of uterine prolapse, age, parity, dystocia, menopause, body mass index, previous prolapse surgery, heavy work, constipation, and chronic cough. RESULTS: Operative time and blood loss were significantly greater (P < .001) in the group with sacrospinous suspension. With a follow-up from 4 to 9 years, 17 (27%) patients receiving sacrospinous suspension had prolapse recurrence at any vaginal site compared with 9 (15%) patients receiving modified McCall culdoplasty (P = .14). Recurrent vault prolapse was recorded in 5 (8%) and 3 (5%) subjects, respectively (P = .72). Thirteen (21%) and 4 (6%) patients, respectively, had recurrent cystocele (matched odds ratio 4.1, 95% confidence interval 1.3 to 14.2, P = .04). No significative difference was observed in postoperative sexual function. CONCLUSION: Sacrospinous ligament fixation is not recommended as a prophylactic measure at vaginal hysterectomy in patients with uterovaginal prolapse.

Adult↗
PubMed1998

Clinical evaluation and applications of the Amplicor HBV Monitor test, a quantitative HBV DNA PCR assay.

Viral load has emerged recently as a reliable marker of disease progression and therapeutic efficacy in chronic infections, including AIDS and hepatitis C. The clinical management of type B hepatitis could also be improved by monitoring viremia levels in patients with chronic liver disease undergoing anti-viral treatment. To address this question we evaluated the performance of a newly developed, quantitative PCR assay (Amplicor HBV Monitor test, Roche Diagnostic Systems) in the assessment of viremia changes over time in a group of 45 patients with chronic active hepatitis (CAH) who received interferon treatment. Of the 45 patients, 14 were HBsAg and anti-HBeAg positive and 31 HBsAg, HBeAg positive. Follow-up extended up to 24 months. An average of ten samples per patient were analyzed for levels of ALT, IgM anti-HBc (Abbott Laboratories), HBV DNA by in-house dot-blot hybridization and hybridization-capture assays (HBV-DNA hybrid capture kit, Murex Diagnostics) and by Amplicor HBV Monitor. A sustained biochemical response was observed at the end of treatment in 12 HBeAg-positive and in seven anti-HBeAg positive patients. This was accompanied by the disappearance of HBeAg and of HBV DNA (hybridization assays) in all cases and by the clearance of IgM anti-HBc in 70% of the cases. Viremia (quantitative PCR assay) became undetectable only in 25-30% of cases and was associated with the loss of HBsAg. A good correlation was observed between the time course of IgM anti-HBc, quantitative PCR and dot-blot hybridization although the latter missed 33% of viremic samples. Together, these results indicate that the Amplicor HBV Monitor test is a robust and standardized assay for quantifying HBV viremia levels in the range from 10(2) to 10(7) copies/ml. Compared to other current markers, viral load may provide additional clinical information by predicting long term virologic response and HBsAg clearance in patients with normal ALT at the end of interferon therapy.

Adult↗
PubMed1998

Impact of HBV, HCV and GBV-C/HGV on hepatocellular carcinomas in Europe: results of a European concerted action.

BACKGROUND/AIMS: To investigate the impact of hepatitis B (HBV) and C (HCV) infections on hepatocellular carcinoma (HCC) in Europe. METHODS: Five hundred and three patients with HCC, from six liver centers, were included. All 503 sera and 80 liver samples were tested for HBV DNA and HCV RNA by polymerase chain reaction. GBV-C/HGV RNA was also tested in 57 sera. RESULTS: HBsAg and anti-HCV were detected in 19% and 40.1% of the patients, respectively. Serum and liver HBV DNA were detected in 82% and 91% of the HBsAg positive subjects. HBV DNA was also detected in the serum and liver of 33% and 47% of HBsAg negative patients. In this group, serum HBV DNA was more prevalent in anti-HBs and/or anti-HBc patients (47.9%), compared to those without any HBV marker (25.1%). HCV RNA was detected in 89% and 7% of anti-HCV positive and negative cases, respectively, HCV 1b being the most prevalent genotype (80%). Coinfection with HBV and HCV was shown in 20.4% of patients, while only 29% had neither HBV nor HCV GBV-C/HGV RNA was detected in only 4/57 sera. CONCLUSIONS: This study offers the first large analysis of HCC in Europe, based on both serology and molecular tests. It demonstrates the major impact of HBV and HCV, but not of GBV-C/HGV, in liver carcinogenesis in Northern as well as Southern Europe. It also stresses the need to use viral genome detection in epidemiological studies when serological tests are negative.

Aged↗
PubMed1998

Pathogenetic and clinical aspects of C1 inhibitor deficiency.

People deficient in C1-INH present recurrent angioedema localized to subcutaneous or mucous tissues. The defect can be caused by impaired synthesis, due to a genetic defect (hereditary angioedema), or by increased catabolism (acquired angioedema). In our experience the majority of patients with acquired angioedema (16 of 18) have autoantibodies to C1-INH in their serum. These autoantibodies bind to C1-INH with different and generally low affinity. The vasopermeability mediator responsible for attacks is still undefined: bradykinin (derived from cleavage of high molecular weight kininogen) and a kinin-like peptide (derived from the second component of complement) still remain the two primary candidates. We examined the systems controlled by C1-INH (complement, contact system, fibrinolysis and coagulation) and found that all of them are activated during angioedema attacks. Activation of the coagulation leads to generation of thrombin whose vasoactive effect can thus influence edema formation. Treatment of severe angioedema attacks is satisfactorily performed with C1-INH plasma concentrate although patients with an acquired defect frequently need very high doses. Attenuated androgens effectively prevent attacks in hereditary angioedema, but their safety, on the very long-term, needs to be further assessed. Acquired angioedema generally fail to respond to these drugs, but can be treated prophylactically with antifibrinolytic agents.

Abdomen, Acute↗
PubMed1998

Anti-tumor immunity induced by murine melanoma cells transduced with the Mycobacterium tuberculosis gene encoding the 38-kDa antigen.

The Mycobacterium tuberculosis Ag38 gene, which encodes a highly immunogenic protein, was cloned into a retroviral vector in-frame with the leader and the transmembrane portion of the nerve growth factor receptor, and transduced into murine melanoma cell line B16-B78. Significant protection was observed in mice immunized with the transduced melanoma cells and subcutaneously challenged with parental melanoma cells since only 20% of mice developed tumors. Necroscopy of mice immunized with the transduced melanoma cells revealed dramatic inhibition of experimental metastases induced by intravenous (i.v.) inoculation of parental melanoma cells. Moreover, vaccination with transduced cells significantly prolonged survival of mice challenged i.v. with parental melanoma cells. These data indicate that the presence of the mycobacterial 38-kDa protein greatly enhances immunological recognition of structures expressed by the parental melanoma cells. Comparison of Th1 and Th2 responses in mice immunized with parental melanoma cells versus mice receiving the transduced cells revealed a clear predominance of Th1 responses when the Ag38 protein was endogenously expressed. This transduction approach may represent a promising immunotherapeutic strategy for the treatment of cancer patients.

Animals↗