Search PubMed⌕ Search

Biomedical subjects

R Colombari

Publications and source records attributed to R Colombari.

At least 19 recordsLinked to original sources
PubMed2006

Finding of conjunctival melanocytic pigmented lesions within pterygium.

AIMS: Conjunctival pigmented lesions have characteristic clinical and histopathological appearances. Melanocytic pigmented lesions commonly occur in the conjunctiva, although they have not been previously reported in pterygium, a common lesion which originates from conjunctiva. Our aim was to evaluate the possibility of an association between pterygium and conjunctival melanocytic pigmented lesions. METHODS AND RESULTS: A total of 80 samples of pterygium excised from Ecuadorian patients in 2002 were collected. Clinical data were available regarding age, sex, race and place of residence. Histological sections were evaluated for the presence of melanocytic pigmented lesions. Nine cases of conjunctival melanocytic, pigmented lesions within pterygium were found and were classified according to the histopathological criteria previously published for pigmented lesions of the conjunctiva, as naevi and primary acquired melanosis (PAM) with varying degrees of atypia. Five of the nine cases showed primary acquired melanosis without atypia, while two cases had atypia; one case showed features of compound naevus and one lesion was designated as subepithelial naevus. CONCLUSIONS: Our findings suggest that conjunctival melanocytic, pigmented lesions occasionally occur in pterygium. All surgically removed pterygia should undergo careful histopathological examination.

Adolescent↗
PubMed2001

In vivo investigation of hepatic iron overload in rats using T2 maps: quantification at high intensity field (4.7-T).

In vivo quantitation of hepatic iron content is useful in diagnosis and staging of several iron related diseases. We used an experimental model of hepatic iron overload to determine the correlation between iron content and T2 relaxation time in rat liver. Experiments were carried out at 4.7T for high signal-to-noise ratio (SNR) using a spin-echo multiecho sequence with six echoes and minimum echo-time of 5.5 msec. The liver iron content was determined ex vivo by atomic absorption spectrophotometry (AAS). T2 maps were calculated in order to evaluate the space distribution of the iron content. We found good linear correlation between the in vivo liver transversal relaxation rate and the iron content within the range explored (106-4538 microg Fe/g liver wet wt.). T2 maps revealed that the decrease in T2 is not homogeneous through the liver parenchyma. This finding represents a physiological limitation to obtaining better correlation between T2 and iron content.

Animals↗
PubMed2000

Hepatocellular carcinoma: correlation between gadobenate dimeglumine-enhanced MRI and pathologic findings.

RATIONALE AND OBJECTIVES: To correlate the appearance of hepatocellular carcinoma on delayed (60 minutes) postcontrast T1-weighted gradient echo images with the mode of action of gadobenate dimeglumine (Gd-BOPTA) and the anatomic and pathologic characteristics of the lesions. METHODS: A total of 34 patients with hepatocellular carcinoma and varying degrees of diffuse liver disease were studied. T2-weighted spin echo and T1-weighted spin echo and gradient echo images were acquired before and 60 minutes after the intravenous administration of 0.1 mmol/kg Gd-BOPTA. Qualitative and quantitative evaluations of the images were performed and correlated with histologic findings. The quantitative evaluation, performed on T1-weighted gradient echo images, looked at the percentage increase of liver enhancement after Gd-BOPTA administration, the lesion-to-liver contrast/noise (C/N) ratio before and after Gd-BOPTA administration, and the C/N variation after Gd-BOPTA administration. Qualitative assessment considered the morphologic features of the lesions as well as the visual variation of contrast before and after Gd-BOPTA administration. Finally, a histologic evaluation was made of the degree of differentiation of the lesions and of the presence of fatty metaplasia, necrosis, bile, or intratumoral peliosis. RESULTS: Among the parameters affecting lesion identification were the extent of liver function, degree of vascularization, residual functionality of the tumor cells, and characteristics of the neoplastic tissue. Positive correlations (Spearman coefficients = 0.359 and 0.393, respectively) were observed precontrast between the degree of liver failure and the amount of contrast noise, and postcontrast between the amount of intralesional fatty metaplasia and the extent to which lesion conspicuity worsened after Gd-BOPTA administration. An inverse correlation (Spearman coefficient = -0.330) was observed between the degree of lesion differentiation and the visible appearance after Gd-BOPTA administration, with well-differentiated lesions tending toward worsened conspicuity postcontrast. A statistically significant difference (P = 0.001) was observed in the mean precontrast C/N ratio for lesions later showing unchanged conspicuity and worse conspicuity on postcontrast images, respectively. Marked variation (P = 0.019) was also observed between Child A and B cirrhotic patients for the degree of hepatic enhancement on postcontrast images. CONCLUSIONS: The results suggest that liver parenchyma signal intensity is influenced by the extent to which liver function is compromised, that residual hepatocytic functionality permits Gd-BOPTA uptake by certain lesions and that this uptake might subsequently impair the observed C/N ratio on delayed images, and that the worsening of lesion conspicuity on postcontrast images is influenced also by high quantities of intralesional fatty metaplasia.

Carcinoma, Hepatocellular↗
PubMed1999

Hepatic angiomyolipoma: a clinicopathologic study of 30 cases and delineation of unusual morphologic variants.

Hepatic angiomyolipoma (AML) is frequently misdiagnosed. HMB-45 is a promising immunomarker for this tumor that leads to recognition of some AMLs with unusual morphology. The purpose of this collaborative study is to better define the morphologic variations of AML. Thirty AMLs were examined, including four biopsy specimens and two fine-needle aspirates. The diagnosis was confirmed by the presence of HMB-45-positive myoid cells. Almost half the cases were originally misdiagnosed as carcinomas or sarcomas. There was marked female predominance (25:5), and the mean age was 48.7 years (range 29-68). Three patients (10%) had evidence of tuberous sclerosis and all had renal AML. According to the line of differentiation and predominance of tissue components, the tumors was subcategorized into mixed, lipomatous (> or = 70% fat), myomatous (< or = 10% fat), and angiomatous type. The mixed type was the most common (11 resected cases), comprising sheets of epithelioid muscle cells admixed with islands of adipocytes, abnormal vessels, and frequently, hematopoietic cells. Six tumors (including three from biopsy specimens) were heavily fatty and showed predominantly adipocytes with epithelioid and short spindle myoid cells webbed between fat cells. Of 10 myomatous AMLs, five tumors showed a pure sinusoidal trabecular pattern and comprised mainly epithelioid cells. Typically, mature adipocytes were absent or scanty, but fat was seen as fine droplets within cytoplasm or as occasional large globules in sinusoids. Pelioid and inflammatory pseudotumor-like patterns were identified focally. Regarding cellular features of the myoid cells, most of the epithelioid cells were either eosinophilic or clear with spiderweb cell morphology. Three AMLs showed an almost purely oncocytic appearance with scanty fat. Large pleomorphic epithelioid cells existed as small foci. Spindle cells arranged in long fascicles were uncommon. D-PAS-positive globules were common around pelioid areas. Brown pigments with staining characteristics of hemosiderin and/or melanin were noted. In conclusion, we propose HMB-45-positive myoid cells as the defining criterion of hepatic AML, which is a tumor capable of dual myomatous and lipomatous differentiation and melanogenesis. Because of its protean morphologic appearance, recognition of the various variant patterns and cell types is important for a correct diagnosis, assisted by immunohistochemical confirmation with HMB-45. Trabecular and oncocytic cell tumors appear to stand out as distinctive subtypes.

Adult↗
PubMed1998

Prompt hepatitis C virus suppression following hepatitis B virus superinfection in chronic untreated hepatitis C.

The natural course of chronic hepatitis C virus infection after hepatitis B virus superinfection is not clear since it is difficult to determine the chronology of the double infections. We report on a case of de novo hepatitis B virus infection in the course of chronic untreated hepatitis C, in which the time of hepatitis B virus infection is actually known. The patient eliminated HCV-RNA, both from serum and from liver tissue, soon after the clinical onset of the acute hepatitis B. Liver histology featured hepatitis with severe portal inflammation and high-grade periportal and intralobular necro-inflammatory lesions. This observation demonstrates that hepatitis C virus replication can be promptly and spontaneously suppressed by acute hepatitis B virus superinfection.

Acute Disease↗
PubMed1997

Serum laminin and type III procollagen in chronic hepatitis C. Diagnostic value in the assessment of disease activity and fibrosis.

Laminin P1 (pepsin-resistant fragment of laminin) and aminoterminal peptide of type III procollagen are measurable in serum and are now considered useful serum markers of fibrogenesis and inflammation in chronic liver diseases. However, very few studies thus far have focused on assessing the diagnostic value of these markers in detecting fibrosis and necro-inflammatory activity in chronically diseased liver. The aim of the present study was therefore to investigate the correlations of laminin and type III procollagen with liver histology and to compare their diagnostic value in detecting the degree of liver fibrosis and necro-inflammatory activity in a homogeneous group of 99 patients suffering from chronic hepatitis C, and lacking other factors which can directly affect the serum levels of the two markers. Both these serum markers were measured by radioimmunoassay, employing commercially available kits. The three main aspects of liver pathology, i.e. portal-periportal activity, lobular activity and fibrosis, were histologically evaluated and semiquantitatively expressed by numerical scores. The results of this study show that laminin and type III procollagen were both positively correlated with the histological scores for portal-periportal activity and with those for fibrosis, whereas no significant correlation was observed between each of the two serum markers and the histological scores for lobular activity. The sensitivity and specificity of laminin and type III procollagen in detecting histological aspects of fibrosis and disease activity in liver, computed at various cut-off levels, showed overlapping trends for the two markers; however, the diagnostic value was in general rather low, whatever the cut-off considered. We therefore conclude that the 'static' measurement of both serum laminin and type III procollagen is of limited value for individual diagnosis of liver damage.

Adolescent↗
PubMed1997

Sjögren's syndrome associated with autoimmune hepatitis. A case report.

Liver involvement in patients with primary Sjögren's syndrome is rare, usually without clinical significance and histologically characterized by a feature like stage 1 primary biliary cirrhosis. We describe herein a case of acute and severe autoimmune hepatitis in a patient suffering from primary Sjögren's syndrome. The diagnosis of Sjögren's syndrome was performed in 1989. In June 1995 the patient presented severe weakness, jaundice and elevation of transaminases; moreover IgG raised to 5560 mg/dl and ANA titre increased to 1:20480. The patient denied alcohol and drug use and a viral hepatitis was excluded. Antimitochondrial antibodies, anti-smooth muscle antibodies and antibodies against liver kidney microsomes were negative. An abdomen ultrasound examination revealed hepatomegaly, with irregular echogenic structure and lymphoadenomegaly near the celiac tripod. Liver biopsy demonstrated a picture of autoimmune hepatitis. The patient was treated with prednisone 50 mg/day and azathioprine 50 mg/day, with improvement in clinical and liver function indices. At present, the patient is given only 10 mg/day of prednisone. The association of Sjögren's syndrome with autoimmune hepatitis is very rare: in the literature only one other similar case has been reported.

Autoimmune Diseases↗
PubMed1996

Serum laminin P1 in chronic viral hepatitis: correlations with liver histological activity and diagnostic value.

Laminin is a major basement membrane-associated, non-collagenous glycoprotein of the extracellular matrix and is deposited in the space of Disse during sinusoidal capillarisation. Laminin P1, a pepsin-resistant fragment originating from the central portion of the cross-shaped laminin molecule, is detectable in serum and has been related to liver fibrosis and portal hypertension. In this study we investigated the behaviour of serum laminin P1, measured by radioimmunoassay, in a homogeneous group of 95 patients suffering from chronic viral hepatitis, types C or B, in order to determine the relationships between serum laminin P1 and each of the main histological aspects of the disease process (i.e. portal-periportal activity, lobular activity and fibrosis), which were assigned numerical scores. Moreover, we computed, at several cut-off levels, the sensitivity, specificity and positive and negative predictive values of laminin P1 in detecting both necroinflammatory activity and fibrosis in the liver. The results show that serum laminin P1 levels parallel the severity of liver disease, the highest laminin concentrations being observed in cirrhotic patients. They suggest also that serum laminin P1 should be considered a marker of the liver disease process as a whole, rather than a marker exclusively linked to fibrosis. Nevertheless, the usefulness of serum laminin P1 measurement, as investigated in this study, seems too limited to be recommended for routine clinical practice.

Adolescent↗
PubMed1996

Long-term variations of serum laminin and procollagen III peptide in chronic HCV hepatitis after alpha-interferon therapy.

Twenty-three out of 40 patients affected by chronic HCV hepatitis responded (i.e. aminotransferases returned to normal) after 6-month treatment with 6 MU tiw of recombinant alpha-interferon 2a (IFN); in 11 (Group 1), the remission was maintained for a mean observation time of 33.15 months (range 20-50) after withdrawal of therapy; 12 (Group 2) relapsing after IFN withdrawal, were treated again obtaining in 10 a second response. Seventeen did not respond (Group 3). Serum markers of connective tissue metabolism (laminin and aminoterminal peptide of type III procollagen -NPIIIP-) were assayed in all patients before treatment and every 6th month, to evaluate long-term effects of IFN therapy. In non-responders, NPIIIP after treatment was not different from baseline, while laminin significantly increased at 6 and 12 months; in responders, NPIIIP decreased significantly after therapy, maintaining values lower than baseline on long-term observation. Laminin decreased significantly six months after the end of therapy and remained lower than baseline in all sustained responders. In this group, the drop in laminin was progressive, whereas in Group 2, laminin showed only a slight decrease on long-term control. Our data show that these serum markers persistently decrease in sustained responders to IFN, while in relapsed cases, prolonged therapy is needed to obtain minor effects on laminin; on the contrary, in non-responders, NPIIIP remains unchanged and laminin significantly increases, suggesting a persistence of active fibrogenesis.

Antiviral Agents↗
PubMed1995

alpha-Interferon treatment of chronic hepatitis C: a controlled, multicentre, prospective study.

This prospective, controlled study was designed in order to evaluate the response rate to alpha-interferon (IFN) versus no treatment in 63 patients affected by chronic hepatitis C. Fifty-two patients were randomly chosen to receive no treatment of IFN alfa-2b (6 MU 3 times weekly for the first month and 3 MU for the next 11 months). Eleven additional patients were crossed to active treatment after a 1-year control period without any change of serum pattern and were therefore enrolled both as controls and cases. Four patients had to be withdrawn from the active treatment for adverse effects. Sixteen out of the remaining 23 had normal alanine aminotransferase (ALT) values at the end of the treatment, and 14 were still normal 12 months later. A liver biopsy, taken 6 months after the end of the treatment, showed improvement in 12 patients and normalization in 1. Only 1 out of the 25 controls had transaminase normalization and 5 a decrease. One of them showed also a histological improvement. Eight of the 11 case/control patients showed ALT normalization after IFN administration, 5 of them histological improvement and 2 liver normalization. Hepatitis C virus (HCV) RNA became negative in 13 of 17 cases in whom the assay was carried out. Therefore this study confirms that the longterm administration of alpha-IFN induced a prolonged remission of disease activity in over 50% of the patients and the clearance of HCV RNA in the majority of the responders.

Adult↗
PubMed1994

[The therapeutic strategy in benign liver tumors: a 20-year experience].

Therapeutic choices for benign liver tumours have changed over the last 20 years. From 1975 to December 1993, we observed 145 hemangiomas (HMG) (57.2% females-mean age 47.3 years, 42.8% males-mean age 50.4 years): we resected 42 symptomatic hemangiomas: mortality rate was 2.3%. 93 HMG without symptoms were only followed-up: 5 of these increased in size and were resected. 27 symptomatic cases over 50 focal nodular hyperplasia (FNH) were resected, 7 cases were resected and 3 biopsied during laparotomy performed for other pathology. Postoperative mortality was nil. 13 cases were only followed-up after diagnosis by imaging techniques and fine needle biopsy: over a mean period of 23 months. No variations have been recorded. Increases in GGT and ALP were present respectively in 34% and 22% of FNH-cases. Scintigraphic techniques were the most diagnostically accurate (96.2%). All 16 hepatocellular adenomas (HCA) were removed (11 females, 5 males), postoperative mortality was nil: oestrogen administration was present in 36.4% of female cases, histological diagnosis v/s well differentiated hepatocellular carcinoma was difficult in 2 cases, whilst 3 cases had spontaneous rupture. We resected also 8 cases of biliary adenomas in order to determine a precise diagnosis v/s liver metastases, and 4 biliary cystadenomas for their malignant potential. Asymptomatic HMG and FNH for their low tendency to increase, can be only observed, whilst HCA must be fully resected for risk of bleeding and misdiagnosis v/s well differentiated hepatocellular carcinoma.

Adenoma, Liver Cell↗
PubMed1994

[Postoperative ischemic ileocolitis in the elderly. Suggested therapy with intraluminal administration of oxygen and glutamine].

Ischaemic ileocolitis in postoperative course of major abdominal surgery is a great challenge for the surgeon: the mortality rate is very high, and therapeutic choices are poor. In the elderly patients ischaemic bleeding ileocolitis is often determined by low flow: sepsis and cytologic damage are primed by activation of endotoxins and chemical mediators, and bacterial translocation could develop across intestinal wall. In our case the patient (male, caucasian, 68 years old) underwent bilio-hepatic resection for hilar cholangiocarcinoma. In the postoperative period continuous enteric haemorrhage was determined by an ischaemic ileocolitis demonstrated by colonoscopy. Abdominal angiography did not show stenosis or occlusion of mesenteric vessels. We administered dopamine and dobutamine as vasodilator drugs for splanchnic circulation without any positive response. Surgical removal of the colon was unsuccessful to stop bleeding. ileostomy and sigmostomy were performed. Histologic samples of the specimen showed ischaemic ileocolitis. After a few days the patient bled again. As last therapeutic choice, we bubbled oxygen in a solution of L-glutamin 500 mml (3 liters/min for 5 min). We administered 500 mml of this solution three times a day by enteral sond, and 100 mml twice a day by sigmoidostomy and endoluminal oxygenation was performed twice a day (1l/min for 1-2 minutes) under continuous control. Bleeding was reducing during the next five days, until stopping. If glutamine and O2 can be considered the fuel of enterocytes, we hypothesized endoluminal oxygenation and glutamine enteral supply of the small intestine could feeding enterocytes, until a complete restoration of enteral mucosa and stopping of the haemorrhage.

Aged↗