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Biomedical subjects

C Negri

Publications and source records attributed to C Negri.

At least 73 records · Page 4Linked to original sources
PubMed1985

[Transitory increase of OKT4+ lymphocytes in the peripheral blood of patients with lymphadenopathy syndrome treated with beta-interferon].

A therapeutic trial with IFN-beta (Hu. Interferon beta lyophilized, Sclavo S.p.A., Siena, Italy), administered thrice weekly but once monthly in six courses was performed for immune-modulating purposes in five parenteral drug addicts affected with lymphadenopathy syndrome. Each dose consisted of 12 X 10(6) international units I.V. Preliminary observations evidenced a significant increase of OKT4+ cells after the first course of therapy. No significant differences from the basal values, though, were found after the following courses, while in a control group of untreated LAS patients, a significant decrease of OKT4+ lymphocytes was observed. Partial remission of symptoms and/or reduction in size of the lymphatic masses were also achieved in all treated patients, although so far none of them can be considered as actually cured.

Antibodies, Monoclonal↗
PubMed1985

Attempt to treat acute type B hepatitis with an orally administered thymic extract (thymomodulin): preliminary results.

A double-blind trial with thymomodulin (TM) was performed in a consecutive series of 50 inpatients affected with acute type B hepatitis. Twenty-six randomly selected patients received TM (Leucotrofina, Ellem), 1 ampoule b.i.d. per os for 30 days, and 24 patients received the same amount of placebo for the same period. TM-treated patients showed accelerated AST and ALT decrease and an earlier HBsAg clearance. However, only the difference in ALT decrease was statistically significant in comparison with the controls (p less than 0.02). Before the treatment was started, lymphocyte subsets, as determined by monoclonal antibodies, showed a different pattern in the two groups despite strict randomization. Nevertheless, by the end of the trial, mean T4+/T8+ ratios were increased in the treated group, but remained unchanged in the control group. The trends in the two groups were significantly different (p less than 0.005). Further information is expected from a long-term follow-up.

Acute Disease↗
PubMed1984

Immune response in a symptomatic case of Tetrapetalonema perstans infection.

The immune response in a 49-year-old Italian nun affected by Tetrapetalomena (Dipetalonema) perstans following an eight-year stay in Cameroon is reported. On admission the patient presented with polyarthralgia, conjunctival pruritus and irritation, oedema of the limbs, generalized itching, hypereosinophilia and low total IgE titre. During diethylcarbamazine treatment and, subsequently, during mebendazole administration, an exacerbation of her symptoms was observed. At the same time, activation of the alternative complement pathway and the appearance of circulating immune complexes were noted, suggesting a type III hypersensitivity reaction. Circulating immune complexes and diethylcarbamazine-induced release of parasitic antigens may also be considered responsible for the decrease of OKT3 and OKT4 positive lymphocytes.

Antibody Formation↗
PubMed1984

[Generalized and persistent lymphadenopathy in drug addicts: clinical and epidemiological aspects].

Persistent unexplained lymphadenopathy with intermittent fever, weight loss, night sweats and malaise was observed in the period from March 1983 to April 1984 in 66 intravenous drug addicts living in Milan. A high percent of these subjects showed cellular immunity alterations, with significant decrease of total lymphocyte count (p less than 0.001) and of OKT4+ cells (percent and absolute number) (p less than 0.001) OKT8+ cells were augmented in percent, but not in absolute count. OKT4/OKT8 cell ratio were inverted, with significant reduction versus the healthy controls (p less than 0.001). IgG mean concentrations were significantly higher than the normal (p less than 0.001). Anergy or hypoergy to recall skin testing were evidenced in 58/66 patients. Cases of persistent unexplained lymphadenopathy associated with abnormalities of cellular immunity are considered as a possible prodrom of AIDS and were frequently observed in high risk populations. The occurrence of this clinical syndrome in a urban area may be premonitory of further progression to the epidemic. It will be necessary to assess whether this clinical and immunological picture will result in some of these patients in full blown acquired immunodeficiency syndrome.

Acquired Immunodeficiency Syndrome↗
PubMed1977

The importance of the acetabular rim in the genesis of congenital hip dysplasia. Experimental research.

The posterior aspect of the cartilaginous acetabular rim was surgically removed in very young rabbits in order to study its effect on the further development of the acetabular cavity. A dysplasic change was produced which led to posterior hip dislocation. Through an analysis of the morphological, radiographic and histological findings, and comparison with human congenital hip dislocation, the acetabular rim is considered to be physiologically responsible for the development of the retaining properties of the acetabular cavity. Moreover, a genetic abnormality altering the physiological development of the cartilaginous acetabular rim, is responsible for the non-retaining power of the acetabulum which leads to congenital hip dislocation.

Acetabulum↗
PubMedDate not supplied

Molecular scanning for mutations in the insulin receptor substrate-1 (IRS-1) gene in Mexican Americans with Type 2 diabetes mellitus.

BACKGROUND: Insulin receptor substrate-1 (IRS-1) is an endogenous substrate for the insulin receptor tyrosine kinase, which plays an important role in insulin signaling. Mutations in the IRS-1 gene are associated in some populations with obesity and Type 2 diabetes. METHODS: To determine whether variation in the IRS-1 gene contributes to genetic susceptibility to insulin resistance and Type 2 diabetes in Mexican Americans, the entire coding region of the IRS-1 gene was screened for variation in 31 unrelated subjects with Type 2 diabetes using single-stranded conformational polymorphism analysis (SSCP) and dideoxy sequence analysis. Variants encoding amino acid substitutions were genotyped in 27 unrelated nondiabetic Mexican Americans and in all family members of subjects containing these variants, and association analyses were performed. To trace the ancestral origins of the variants, Iberian Caucasians and Pima Indians were also genotyped. RESULTS: Eight single base changes were found: four silent polymorphisms and four missense mutations (Ala94Thr, Ala512Pro, Ser892Gly and Gly971Arg). Allele frequencies were 0.009, 0.017, 0.017 and 0.043, respectively. There were no significant associations of any of these variants with diabetes, glucose or insulin levels during an oral glucose tolerance test, or with body mass index (BMI) in Mexican American families except for a modest association between the Ala94Thr variant and decreased BMI (30.4 kg/m(2) vs 24.0 kg/m(2); p=0.035). None of these four missense mutations were detected in Pima Indians. In Iberian Caucasians, neither Ala94Thr nor Ser892Gly were detected, and Ala512Pro was detected in only 0/60 diabetic patients and 1/60 nondiabetic controls. Gly971Arg was relatively more common in Iberian Caucasians with 12/58 diabetic patients and 7/60 nondiabetic controls being heterozygous for this variant (p=0.21 for comparison between diabetic and nondiabetic subjects). CONCLUSIONS: Ala94Thr, Ala512Pro and Ser892Gly mutation are rare in the populations studied. Gly971Arg, is more common in Mexican Americans and Caucasians, but is not a major contributor to genetic susceptibility to Type 2 diabetes.

Adult↗
PubMedDate not supplied

Outbreak of persistent, unexplained, generalized lymphadenopathy with immunological abnormalities in drug addicts in Milan.

Persistent unexplained lymphadenopathy (LAS) with intermittent fever, weight loss, night sweats and malaise was observed from March to October 1983 in 16 of 133 intravenous drug addicts who had been followed for at least two years in a Center for Drug Addicts Assistance in Milan, Italy. All the subjects lived in a restricted suburban area and indulged in frequent toxicomanic practices and mutual sexual intercourse. The subjects showed immunological alterations such as lymphopenia (50%), decreased T helper/T suppressor ratio (93%), both these abnormalities (43%), decreased T helper cells (75%), increased T suppressor cytotoxic cells (81%), decreased natural killer (NK) activity (77%), anergy (50%) or hypoergy (43%) to recall skin testing and elevated levels of IgG (87%). Anti-HTLV III antibodies were found in 14 of 16 (87%) patients with LAS and in 3 of 11 (27%) symptom-free drug addicts belonging to the same group. It will be important to assess in the future whether this clinical and immunological picture results in acquired immunodeficiency syndrome in an area so far untouched by this disease.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

A case of Austrian's syndrome with ocular involvement.

A man with a history of alcohol abuse was admitted to hospital with pneumonia and meningitis due to Streptococcus pneumoniae. Because of the worsening of respiratory function and the persistence of fever, an echocardiographic examination was made, which showed endocarditis with destruction of the aortic valve. The patient underwent surgical valve replacement. In addition, he showed a choroiditis in the left eye which improved after antibiotic therapy. The interest of this case lies in the rarity of the triad described as Austrian's syndrome and in the coexistent fourth septic localization, namely in the left eye.

Anti-Bacterial Agents↗
PubMedDate not supplied

Monoclonal antibody-defined T lymphocyte subpopulations in monoclonal gammapathy of undetermined significance.

We used monoclonal antibodies of the OK series to study T lymphocyte subpopulations in 55 patients with monoclonal gammapathy of undetermined significance (MGUS) and in 40 healthy control subjects, with the aim to investigate if alterations in T lymphocyte subpopulations occur also in MGUS. Mean OKT3+ and OKT8+ cell counts were higher (p less than 0.01 and p less than 0.001, respectively) and the mean OKT4/OKT8 ratio was lower (p less than 0.02) in MGUS patients than in the control subjects. MGUS with the IgM-type monoclonal immunoglobulin (IgM-MGUS) showed the most evident derangement of T lymphocyte subpopulations, i.e., a significant increase of OKT8+ cells and a significant reduction of the OKT4/OKT8 ratio. OKT4+ and OKT8+ cells were significantly increased in patients with high paraprotein concentration (above 16 g/l). Our data suggest that alterations of T lymphocytes are present in MGUS, and that they are similar to those observed in malignant lymphoproliferative disorders.

Adult↗
PubMedDate not supplied

Cryoglobulins and infectious diseases.

The relationship between infectious diseases due to various pathogenetic factors and cryoglobulin production mechanisms has been investigated. Cryoglobulins have been evidenced in infections caused by very heterogeneous pathogens, i.e. leptospirosis, psittacosis, Mediterranean tick typhus, brucellosis, gram-negative bacterial septicemias, in which they had never been previously reported. In type A hepatitis a high cryoglobulin prevalence (91%) has been confirmed during the acute phase, with a rapid decrease both in prevalence and concentration in the subsequent stages of the disease. Cryoglobulins were all of type III and were mainly represented by IgM; anti-HAV-IgM antibodies have been evidenced in all but one cryoprecipitates. In non-A, non-B hepatitis a lower cryoglobulin prevalence (44.7%) was shown during the acute phase and the same fast decrease has been noted in the subsequent stages. Cryoglobulins were all of type III and in some cases polyclonal IgG was the only Ig class present in cryoprecipitates. The cryoglobulin prevalence in the acute phase of HBsAg-positive hepatitis amounted to 73.4%; all the cryoprecipitates were of type III. No correlation between the presence of cryoglobulins and HBeAg positivity or between cryoglobulins and delta agent infections was found. In all the cases studied the presence of cryoglobulins was related to the persistence of liver damage. Cryoglobulins were not found in HBsAg chronic carriers, while they have been evidenced, by a preliminary study, in 41.6% of HTLV-III antibody-positive subjects complaining of a persistent generalized lymphadenopathy without clinical or laboratory signs of liver impairment. No HTLV-III antibodies were found by ELISA method in the type III cryoprecipitates.

AIDS-Related Complex↗
PubMedDate not supplied

Poly(ADP-ribose) synthesis: a useful parameter for identifying apoptotic cells.

Cell death by apoptosis was analysed in HeLa cells either treated with the antitumoral drug bleomycin or depleted of growth factors by long-term culture without medium change. The interference of apoptosis with normal cell cycle progression was followed by flow cytometry in cells stained with propidium iodide and with antibody to S-phase-related PCNA protein. Bleomycin-treated cells showed a net accumulation in G2/M phase paralleled by the appearance of material with a subdiploid DNA content. Cells with a subdiploid DNA content were also present in growth factor-depleted cultures and were shown to derive from all the cell cycle phases. To identify apoptotic features in HeLa cell cultures, we applied a recently developed assay based on the simultaneous analysis in the single cell of three parameters, namely chromatin condensation, DNA degradation and poly(ADP-ribose) synthesis. Apoptotic cells were visualized by sequential reactions: Hoechst staining, terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labelling assay and immunoreaction with anti-poly(ADP-ribose) monoclonal antibody. Positive reactions were obtained for cells at different stages of the apoptotic programme showing condensed nuclei, fragmented chromatin and apoptotic bodies.

Apoptosis↗
PubMedDate not supplied

Effects of topoisomerase II inhibitors on gastric cancer cells characterized by different genetic lesions.

Gastric cancer is poorly-responsive to widely used antitumour drugs, the efficacy of which is thought to be related to the capacity of triggering apoptosis. This process requires a series of gene products including a functional p53 protein. We tested the effects of two DNA topoisomerase II poisons, etoposide and doxorubicin, on gastric cancer cell lines with different genetic lesions. We characterised MKN74 and MKN28 cells for p53 gene status and for the expression of p53 and p21 proteins, as well as of topoisomerase II alpha and beta isoforms. After drug treatments, the cells were analysed for drug cytotoxicity, colony forming ability, cell cycle distribution and presence of apoptotic features. Our findings demonstrated that both etoposide and doxorubicin have a potent anti-proliferative effect on gastric cancer cells. Cell death kinetics was different in the two cell lines, MKN74 cells being more sensitive than MKN28 to the drugs. MKN74 cells, although harboring a wt p53 gene, were unable to undergo a massive apoptosis following etoposide treatment. The response of this cell line might be related to the topoisomerase II beta isozyme, the expression of which proved to be undetectable.

Antibiotics, Antineoplastic↗
PubMedDate not supplied

Topoisomerase II alpha and beta in human tumor cells grown in vitro and in vivo.

The cellular content and the cell-cycle distribution of the 170 kD- and 180 kD-isoforms of DNA topoisomerase II were investigated in human tumor cells with specific monoclonal antibodies and by immunofluorescent detection with flow cytometry. Levels of topo II alpha were almost three-fold higher than the beta-isozyme in exponentially growing cells in vitro. In contrast, topo II alpha but not beta, was markedly reduced in plateau-phase cells. Tumor cells from surgical biopsies, mainly in G0/G1 phase, exhibited a 95% beta- versus 5% alpha-isoform expression. These results support the hypothesis that topo II alpha is mainly related to DNA synthesis, and topo II beta to DNA transcription.

Antibodies, Monoclonal↗