Search PubMed⌕ Search

Biomedical subjects

E Silini

Publications and source records attributed to E Silini.

At least 55 records · Page 3Linked to original sources
PubMed1994

Cervical adenocarcinomas express markers common to gastric, intestinal, and pancreatobiliary epithelial cells.

Frequency and pattern of expression of eight markers of gastric, intestinal, and pancreatobiliary duct epithelial cells have been investigated by histochemical and immunohistochemical techniques in 85 cases of cervical adenocarcinomas. M1, a mucin antigen, and Cathepsin E (CaE), an aspartic proteinase, markers of normal gastric superficial/foveolar epithelial cells, are expressed in 40 and 55 tumors, respectively. Periodic acid-concanavalin A-reactive mucin or Pepsinogen (PG) II, markers of gastric mucus neck and pyloric gland cells, are found in 24 tumors, 13 of which also express M1 and CaE. CAR-5 and M3SI, markers of intestinal mucin, are expressed in 68 and 12 tumors and DU-PAN-2, marker of normal pancreatobiliary duct cells, is found in 46 tumors. All but two tumors express at least one of the eight markers studied, none express PG I, marker of gastric chief cells. The different histologic subtypes of cervical adenocarcinomas expressed to a variable degree both gastrointestinal and pancreatobiliary markers. Only endocervical type tumors, however, showed the full spectrum of mucosal pyloric type differentiation, including the expression of PGII which is not present in any other histotype. A correlation between expression of gastroenteropancreatic markers and tumor grade is not apparent in our series.

Adenocarcinoma↗
PubMed1993

Langerhans' cell counts and cervical intraepithelial neoplasia in women with human immunodeficiency virus infection.

The mean counts of Langerhans' cells were evaluated in cervical biopsies obtained from 30 patients with human immunodeficiency virus (HIV) infection and cervical intraepithelial neoplasia (CIN) and from 30 HIV-seronegative control patients. Each HIV-seronegative control was matched to a seropositive case with respect to grade of CIN, age, and smoking habits. Langerhans' cells were identified by immunohistochemical staining for S-100 protein. In situ hybridization with biotinylated probes was performed to detect human papillomavirus (HPV) DNA 6/11, 16/18, and 31/35/51. The mean counts of S-100 positive cells per 100 basal cells were lower in HIV-seropositive patients than in controls (0.99 +/- 0.08 vs 1.9 +/- 0.2 P = 0.024). These differences occurred independent of any coexisting HPV infection. Positive correlations between S-100 positive cell counts and CD4+ and CD8+ cell counts were found in HIV-infected women. AIDS patients had lower Langerhans' cell counts compared both to patients with AIDS-related complex or asymptomatic HIV infection. Our results suggest that local cervical immunity, as evaluated by Langerhans' cell counts, is impaired in HIV-seropositive women. The severity of impairment seems to correlate with the stage of the HIV disease.

Carcinoma in Situ↗
PubMed1993

Enterochromaffin-like (ECL) cells and their growths: relationships to gastrin, reduced acid secretion and gastritis.

ECL cells are argyrophilic endocrine cells of the stomach. Their distribution is species specific, however they are consistently located in the oxyntic mucosa and, in particular, in very close contact with the adenomeres of acidopeptic glands. ECL cells store histamine and are considered a key element in the mechanisms of gastric acid secretion as controlled by gastrin stimulus. Their peculiar anatomical disposition and secretory properties strongly suggest that ECL cells exert their function by a paracrine mechanism, i.e. by releasing histamine in the extracellular spaces surrounding acid-producing parietal cells. ECL cell activity is strongly stimulated by gastrin, which, once applied as a long-standing stimulus, also exerts a potent proliferating effect. Long-lasting hypergastrinaemia has been demonstrated to elicit ECL cell proliferation in laboratory animals, inducing ECL cell hyperplasia, dysplasia and ECL cell tumours, i.e. argyrophilic gastric carcinoids. However, in experimental rodents it is believed that hypergastrinaemia is not per se a stimulus capable of inducing ECL cell transformation, a predisposing genetic background being required for tumour development in endocrine organs. In man, long-standing hypergastrinaemia exerts the same proliferative pressure on ECL cells and is associated with hyperplasia with or without dysplastic changes and carcinoid development. Clinical evidence suggests that other factors, both genetic and environmental, are required to induce ECL cell transformation and carcinoid development. For this reason human gastric argyrophilic ECL carcinoids are subdivided into three main groups depending on their clinical background: (1) gastric carcinoids in patients with chronic atrophic gastritis; (2) gastric carcinoids in patients with Zollinger-Ellison and multiple endocrine neoplasia type 1 syndrome (MEN-ZES); and (3) solitary, sporadic gastric carcinoids. The clinical assessment of carcinoid-bearing patients is strongly recommended for better diagnosis and management of patients.

Animals↗
PubMed1993

Virological features of hepatitis C virus infection in hemodialysis patients.

The clinical and epidemiological relevance of circulating antibodies to hepatitis C virus (HCV) in hemodialysis patients is uncertain, since clinical signs of infection are often mild or absent, with alanine aminotransferase (ALT) values that are virtually always normal, and liver biopsies are only rarely performed. Determination of HCV RNA in serum is therefore critical for distinguishing chronic HCV infection from previous exposure to the virus. We studied HCV viremia by reverse transcription polymerase chain reaction (RT-PCR) in the 5'-noncoding region of the viral genome in 77 dialysis patients who were screened for anti-HCV by a second-generation enzyme-linked immunosorbent assay (the enzyme immunoassay II; Ortho HCV, 2nd generation, Ortho Diagnostic Systems Raritan, N.J.) and a second-generation recombinant immunoblot assay (Chiron Corporation and Ortho Diagnostic Systems) and prospectively evaluated for ALT elevations over a period of 5 years. Of 77 patients tested, 29 (38%) had active infection as shown by a positive PCR assay result, and of these, 26 were anti-HCV positive. Although a good correlation was found between circulating anti-HCV and HCV RNA in serum, 10 (28%) of 36 anti-HCV-positive patients were HCV RNA negative by PCR, suggesting either low levels of viremia or past exposure to HCV and subsequent recovery. On the other hand, 3 (7.3%) of 41 anti-HCV-negative patients had HCV RNA in their sera, indicating seronegative HCV infection. The ALT level had no predictive value for HCV infection, because it was repeatedly normal in 18 (62%) of 29 viremic patients. HCV genotyping was also performed and indicated that all four known genotypes of HCV were present in our group. In conclusion, serological assays are reliable for detecting exposure to HCV in hemodialysis patients; however, direct identification of the viral genome is required to document current infection.

Adolescent↗
PubMed1993

Aspartic proteinases in normal lung and interstitial pulmonary diseases.

Two aspartic proteinases, pepsinogen II (PgII) and cathepsin E (CathE), were identified immunocytochemically in lung epithelia. In normal lung, type II pneumocytes were characterized by PgII immunoreactivity of variable intensity, while bronchiolar Clara cells reacted with CathE antibodies. With the exception of small groups of nonciliated bronchial cells overlying lymphoid follicles, no other CathE-immunoreactive cell was found in the lung. Immunoblots of crude protein extracts of lung tissue using PgII and CathE antibodies showed reactivity with single molecular species co-migrating with analogous bands obtained from gastric mucosa (molecular weight, 40,500 for PgII and 42,000 to 44,000 for CathE). In 75 cases of non-neoplastic lung disease, a highly significant correlation was found between the severity of histopathologic lesions and expression of both PgII (P < 0.001) and CathE (P < 0.001). Epithelial hyperplasia contributed more than inflammation and fibrosis to this relationship. Proteinase overexpression was not specific to any particular disease and was found in both focal and diffuse lesions. Segregation of PgII and CathE in different cells was lost in hyperplastic epithelium, where coexpression of both proteinases by the same cell was frequently observed. The location of both proteinases in distal airways and their enhanced expression in the proliferative, hyperplastic phase of several non-neoplastic pneumopathies suggest their possible involvement in the process of parenchymal remodeling that occurs in fibrosing lung diseases.

Cathepsin E↗
PubMed1993

Cathepsin E in antigen-presenting Langerhans and interdigitating reticulum cells. Its possible role in antigen processing.

A specific rabbit anti-human cathepsin E serum detected this aspartic proteinase in Langerhans cells of the skin, in interdigitating reticulum cells of lymph nodes and spleen and in histiocytosis X cells, but not in macrophages. Immunoblotting of tissue extracts confirmed the presence of cathepsin E in skin and lymph nodes. Electron immunocytochemistry with the protein A gold technique localized cathepsin E in the endoplasmic reticulum and in endosomal vesicles of both interdigitating and Langerhans cells, likely involving Birbeck bodies. A role of endosomal cathepsin E in antigen processing is suggested.

Cathepsin E↗
PubMed1992

Search for Coxsackievirus B3 RNA in idiopathic dilated cardiomyopathy using gene amplification by polymerase chain reaction.

A polymerase chain reaction (PCR) amplification assay was developed to detect Coxsackievirus B3 ribonucleic acid (RNA) in blood and myocardial tissue of explanted hearts from 40 patients who underwent cardiac transplantation and in 1 normal heart. Twenty-one patients were affected by idiopathic dilated cardiomyopathy of different duration and 19 by coronary artery disease. Coxsackievirus B3 in vitro infected Vero cells and cells infected by related human enteroviruses (Coxsackievirus B2, B4, and poliovirus 1) were used as reaction controls. PCR was performed using 4 pairs of primers homologous to Coxsackie-virus B3 sequences. Three sets were located in regions of the genome conserved at nucleotide level between several enterovirus species (replicase gene, 5' noncoding region), while one was located in a Coxsackievirus B3-specific region (VP1 gene). Total RNA was prepared by acid guanidinium isothiocyanate extraction from tissue stored frozen at -80 degrees C. One microgram of total RNA was retrotranscribed with either antisense primer or with random hexanucleotide primers and then subjected to 40 cycles of amplification. PCR products were separated by electrophoresis on a 10% polyacrylamide gel, electrotransferred to a nylon membrane and then hybridized to oligonucleotide probes specific for the coxsackievirus B3 genome radiolabeled with radioactive isotope of phosphorous. All pairs of primers yielded specific amplification products when tested on Coxsackievirus B3-infected Vero cells, with a sensitivity of 1 infected cell out of 10(5) to 10(6) cells starting from 1 microgram total RNA. Primer sets for regions of Coxsackievirus B3 genome highly conserved between related enteroviral species gave positive amplification also when challenged with RNA from cells infected by Coxsackievirus B2, B4 and poliovirus 1.

Adult↗
PubMed1992

Development and clinical significance of a diagnostic assay based on the polymerase chain reaction for detection of human cytomegalovirus DNA in blood samples from immunocompromised patients.

The presence of human cytomegalovirus (HCMV) DNA in blood was investigated by the polymerase chain reaction (PCR) in 293 blood samples from 86 immunocompromised patients. Of the 86 patients, 23 underwent clinical and virologic follow-up for HCMV infection. In parallel, blood samples were examined for viremia and antigenemia. Concordant results between PCR and assays for viremia and antigenemia were obtained on 124 positive and 110 negative samples, with an overall concordance of 79.8%, while 59 samples (most from patients with HCMV infection) were positive by PCR alone. PCR is a new powerful tool for detection of HCMV infections in blood samples from immunocompromised patients. However, its clinical significance appears to be restricted to the indication of a risk of reactivation of HCMV infection.

Antigens, Viral↗
PubMed1991

Monitoring of human cytomegalovirus infections and ganciclovir treatment in heart transplant recipients by determination of viremia, antigenemia, and DNAemia.

Fourteen heart transplant recipients were monitored for human cytomegalovirus (HCMV) infection based on determination of antigenemia, viremia, and DNAemia (by polymerase chain reaction [PCR]) in peripheral blood polymorphonuclear leukocytes (PMNL). Three patients had symptomatic primary, 10 had recurrent (3 asymptomatic), and 1 (seronegative) had no HCMV infection. Severe clinical symptoms appeared when levels of viremia/antigenemia were greater than 50 infected PMNL/2 x 10(5) cells examined. Of 200 blood samples examined, 93 (46.5%) were positive for viremia/antigenemia and DNAemia, whereas 48 (24.0%) were positive for DNAemia only; 59 (29.5%) were negative in all assays. Follow-up of HCMV infections in heart transplant recipients showed that PCR can detect viral appearance in blood 7-10 days earlier than assays for antigenemia/viremia. On the other hand, viral disappearance from blood, as assessed by PCR, occurred weeks or months later than revealed by other assays. Detection of virus by PCR only was never associated with overt HCMV-related clinical symptoms. Of the 8 symptomatic patients treated with ganiclovir, 2 became PCR-negative at the end of treatment and 1 cleared virus from blood in the following weeks, whereas 5 showed persistent or recurrent infection.

Antigens, Viral↗
PubMed1990

Human cytomegalovirus viraemia in HIV-1-seropositive patients at various clinical stages of infection.

Eighty-two HIV-1-seropositive subjects were examined for the presence and quantification of human cytomegalovirus (HCMV) in peripheral blood polymorphonuclear leukocytes (PMNL) by polymerase chain reaction, culture and immunofluorescence in order to investigate the relationship between viraemia and immunosuppression. Patients were divided into three groups: (1) asymptomatic subjects with greater than 400 x 10(6)/l CD4 lymphocytes (n = 30); (2) asymptomatic subjects with less than 400 x 10(6)/l of CD4 lymphocytes and zidovudine (n = 20), and (3) AIDS-related complex (ARC)/AIDS patients on zidovudine (n = 32). Evidence of HCMV infection in circulating PMNL was found in 15 out of 29 ARC/AIDS patients examined (51.7%), whereas no infection was detected among the 50 asymptomatic HIV-1-seropositive subjects. HCMV-related symptoms were found only where the number of infected PMNL was greater than 50 per 2 x 10(5) cells.

AIDS-Related Complex↗
PubMed1990

Identification of human cytomegalovirus isolates by the polymerase chain reaction.

Fifty human cytomegalovirus (HCMV) isolates were recovered from different clinical specimens (buffy coat, throat washing and urine) obtained from fifty patients (23 AIDS patients, 20 heart transplant recipients, 1 bone marrow transplant recipient, 2 newborns with congenital HCMV infection and 4 immunocompetent individuals with acute HCMV infection). The isolates were previously identified by immunological methods and then examined for identification by the polymerase chain reaction. In parallel, reference HCMV strains as well as other human members of the Herpesviridae family (reference and wild strains) were examined as controls. Two pairs of primers relevant to the immediate-early and late regions of HCMV DNA, respectively, were used. The DNA amplification product was highly specific; in addition, all fifty HCMV isolates were amplified by both pairs of primers and thus identified as HCMV. These preliminary results show that selected pairs of primers are able to amplify DNA regions conserved enough to allow virus identification among a large number of HCMV strains. In addition, they are highly promising in view of the use of PCR for direct detection of HCMV DNA in clinical samples.

Cytomegalovirus↗
PubMed1987

Endocrine cells producing regulatory peptides.

Recent data on the immunolocalization of regulatory peptides and related propeptide sequences in endocrine cells and tumors of the gastrointestinal tract, pancreas, lung, thyroid, pituitary (ACTH and opioids), adrenals and paraganglia have been revised and discussed. Gastrin, xenopsin, cholecystokinin (CCK), somatostatin, motilin, secretin, GIP (gastric inhibitory polypeptide), neurotensin, glicentin/glucagon-37 and PYY (peptide tyrosine tyrosine) are the main products of gastrointestinal endocrine cells; glucagon, CRF (corticotropin releasing factor), somatostatin, PP (pancreatic polypeptide) and GRF (growth hormone releasing factor), in addition to insulin, are produced in pancreatic islet cells; bombesin-related peptides are the main markers of pulmonary endocrine cells; calcitonin and CGRP (calcitonin gene-related peptide) occur in thyroid and extrathyroid C cells; ACTH and endorphins in anterior and intermediate lobe pituitary cells, alpha-MSH and CLIP (corticotropin-like intermediate lobe peptide) in intermediate lobe cells; met- and leu-enkephalins and related peptides in adrenal medullary and paraganglionic cells as well as in some gut (enterochromaffin) cells; NPY (neuropeptide Y) in adrenaline-type adrenal medullary cells, etc.. Both tissue-appropriate and tissue-inappropriate regulatory peptides are produced by endocrine tumours, with inappropriate peptides mostly produced by malignant tumours.

Animals↗
PubMed1987

Molecular analysis of mbcl-2: structure and expression of the murine gene homologous to the human gene involved in follicular lymphoma.

We have cloned the mouse bcl-2 (mbcl-2) genomic locus and analyzed it in detail. The gene is comprised of two exons separated by more than 15 kb. Two species of mRNAs are produced, and DNA sequencing analysis shows that they code for two proteins differing at their C terminus: a 7.5 kb transcript codes for a polypeptide of 236 amino acids, mbcl-2 alpha, and a 2.4 kb transcript, which derives from the 5' exon only, codes for a protein of 199 amino acids, mbcl-2 beta. The gene is characterized by very long (5' about 1.4 kb, and 3' about 5.1 kb) untranslated regions surrounding the relatively short coding region. We have mapped the 5' end of the mbcl-2 mRNAs by S1 protection analysis, and we have analyzed the promoter region. The expression of the mbcl-2 gene was analyzed in different cell lines and in mouse tissues. Expression is tissue-specific in adult tissues: spleen and thymus express the highest level of mbcl-2 transcripts. The mbcl-2 gene maps to mouse chromosome 1.

Amino Acid Sequence↗
PubMed1987

Association of BK virus with human brain tumors and tumors of pancreatic islets.

BK virus (BKV) DNA was detected by Southern blot hybridization in 19 out of 74 (25.6%) human brain tumors and in 4 out of 9 (44.4%) human tumors of pancreatic islets. BKV DNA was free, in an episomal state and generally in a low copy number (0.2 to 2 genome equivalents per cell). Only occasional tumors contained 10 to 20 genome copies per cell. Viral DNA sequences integrated into cellular DNA were not detected. A number of tumors expressed BKV-specific RNA and T antigen. By transfection of total tumor DNA into human embryonic fibroblasts, viruses with the biological and antigenic properties of BKV were rescued from 6 brain tumors and from 2 tumors of pancreatic islets. Restriction endonuclease mapping of the genomes of the rescued viruses showed that they differ from wild-type BKV. They are all similar to each other and to BKV-IR, a virus previously rescued from a human tumor of pancreatic islets, suggesting the possible association of a BKV variant with specific types of human neoplasms. The significance of the relationship of these BKV variants to human tumors and their possible etiologic role in human oncogenesis are discussed.

Adenoma, Islet Cell↗