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Biomedical subjects

G Santini

Publications and source records attributed to G Santini.

At least 127 records · Page 7Linked to original sources

Immunohistochemical, enzyme histochemical, and immunologic features of giant lymph node hyperplasia of the hyaline-vascular type.

A combined histologic, immunohistologic, enzyme histochemical, and immunologic study has been carried out in a 7-year-old girl with recurring extramediastinal monocentric giant lymph node hyperplasia of hyaline-vascular type. A large panel of monoclonal and polyclonal antibodies to lymphoid and nonlymphoid cell markers were tested on frozen and paraffin-embedded lymph node tissue as well as on cell suspension and peripheral blood. Tissue enzyme histochemical study, including a conventional hematologic panel, was performed on frozen and plastic-embedded sections. The pattern was dominated by nodular aggregates of round BA-1+ Leu-14+ HLA-DR+ ATPase+ lymphocytes with polyclonal sIgD and sIgM positivity and lacking cIg and BA-2 staining. Leu-1+/Leu-4+, OKT6+, OKT10+, Leu-7+, and CALLA+ cells were few or absent in the nodules, whereas DRC-1+ BA-2+ HLA-DR+ 5'-Nuc+ cells formed a dendritic network in the outer portion of the nodules. No immunoreactivity for lymphoid and nonlymphoid cell markers, including cytokeratin and keratin, was detected in centrinodular histiocytic-like cells. Particularly, the Hassall's-like structures contained a target-like positivity for laminin, and consisted of flattened acid phosphatase (AP), alpha-naphthyl acetate esterase (ANAE), 5'-nucleotidase (5'-Nuc), and adenosine triphosphatase (ATPase) positive cells, whose enzyme profile overlapped with that of the histiocytic-like cells. The extranodular areas were mainly composed of Leu-1+/Leu-4+ lymphocytes with Leu-3a+/OKT4+ phenotype and, to a lesser extent, of OKT6+ OKT10+ lymphoid cells and scattered cells with markers of histiocytic lineage. The abundant vascular component was generally identified by laminin positivity and, in smaller proportion, it was positive for Factor VIII-related antigen. Most of the medium-sized vessels with high endothelium had marked AP, ANAE, and ATPase activities. The process observed resulted from vascularized nodular aggregates of nontransformed B-cells with the phenotype of primary follicle lymphocytes, associated to centrinodular histiocytic-like cells with a distinct enzyme profile.

Antibodies, Monoclonal↗

Influence of ofloxacin on murine Peyer's patch lymphocytes.

Several factors must be considered before the clinical impact of antimicrobials on the immune function can be determined. No data are available as yet on the influence of ofloxacin, a new fluoro-quinolone, on the lymphocytes of Peyer's patches. The present study offers evidence that murine Peyer's patches are influenced by ofloxacin administered by the oral route for seven days (15 mg/kg). No modifications of the percentage of the Thy 1,2 and SIg positive splenocytes and of the PHA and LPS-induced proliferative responses were observed studying cell suspensions from the spleen of the same animals. An immunotoxic effect of the compound on the cells of Peyer's patches or an impairment of their homing tendency has been postulated.

Animals↗

Giant lymph node hyperplasia: a disease of primary follicle/mantle zone lymphocytes?

Histological, immunohistochemical, and immunological features of a lymph node from a patient with Castleman's disease (CD), hyaline vascular type, were investigated. The results substantiate a peculiar immunological identity of this disease. CD lymph nodes consisted mainly of polyclonal primary follicle/mantle zone lymphocytes. Germinal center cells and plasma cells were absent, while T-lymphocyte subsets were not modified.

Antibodies, Monoclonal↗

Persistent generalized lymphadenopathy: clinical characteristics of a lymphadenopathy syndrome in intravenous drug abusers.

Persistent generalized lymphadenopathy (PGL) is the most frequent AIDS related manifestation in homosexual men. From May 1984 to March 1985, 45 (38%) out of 117 intravenous (iv) drug abusers evaluated had PGL. Thirty-two were males and 13 females (median age 25 years). All patients referred to the frequent sharing of syringes. The median duration of lymphadenopathy was 3 months (range 3-60) with a median number of involved extrainguinal sites of 4 (range 2-7). Systemic symptoms and energy to skin tests were common, whereas splenomegaly and past infections were less frequently encountered. Hypergammaglobulinemia and an inverted T helper/suppressor ratio and lymphopenia were found in 78%, 43%, and 20% of the patients, respectively; the presence of HTLV-III antibodies was demonstrated in 12 (46%) of the 26 tested patients. Histologically, excised lymph nodes from 14 patients exhibited a marked follicular hyperplasia, diffuse plasmacytosis, and a conspicuous capillary proliferation. All patients are followed on a regular basis with clinical examination and laboratory tests; in no case has AIDS or a malignant lymphoma so far developed.

AIDS-Related Complex↗

Persistent generalized lymphadenopathy in Northeastern Italy: increased frequency of HLA-DR 5.

We undertake a study of Italian intravenous drug abusers and male homosexuals with the prolonged generalized lymphadenopathy syndrome (PGL). 75% of the subjects had the HLA-DR 5 antigen (relative risk 3.25). Only one patient was DR 2 positive. 14/20 subjects had anti-HTLV III antibodies and immunological malities were a rather constant finding.

Acquired Immunodeficiency Syndrome↗

OKT4+ chronic lymphocytic leukaemia cells display different reactivity with selected monoclonal antibody combinations.

Four cases of chronic T lymphocytic leukaemia are characterized by selected monoclonal antibody combinations and double-fluorescence studies. We found 3 possible combinations: OKT4++ Leu8++ Leu9+, OKT4++ Leu8+ Leu9- and the OKT4++ Leu9++ Leu8- phenotypes are correlated with different biological aspects of the disease. No markers of T cell activation were found, and serological examinations did not reveal anti-HTLV-I antibodies. In considering a larger number of patients, multiparametric analysis could be useful to better classify this heterogeneous type of leukaemia.

Aged↗

[Comparative evaluation of various direct and culture methods for the diagnosis of genital Chlamydia trachomatis infections].

Commercially produced fluorescein labelled monoclonal antibodies for Chlamydia trachomatis detection have been recently become available. We have compared the data obtained using two monoclonal antibodies, one for detecting inclusion on cell cultures (culture confirmation) and the other for detecting C. trachomatis in smears from urethral and cervical swabs, with our routine isolation method which utilizes Giemsa staining of cycloheximide treated McCoy cell cultures. We also evaluated an enzyme immunoassay for detecting C. trachomatis antigens in urethral and cervical specimens. The culture confirmation system was slightly more sensitive and simpler than Giemsa staining. Between the results of immunofluorescence direct test and culture there was 96.3% agreement. Sensitivity, specificity and predictive positive and negative value were 72.2, 98.4, 80 and 97.6%. Between results of culture and enzyme immunoassay there was 97.2% agreement. The immunoassay sensitivity, specificity predictive positive and negative value were, in women, 100, 97.1, 63.6 and 100%; in men, 100, 95.7, 81.8, 100%.

Antibodies, Monoclonal↗

4-Demethoxydaunorubicin (Idarubicin) in refractory or relapsed acute leukemias. A pilot study.

Twenty-five adults with previously treated acute leukemia were treated with 4-demethoxydaunorubicin (Idarubicin) with a daily dose of 8 mg/m2 for 3 days intravenously. Complete remission was achieved in 3 of 18 patients with acute nonlymphoblastic leukemia (ANLL) and 2 of 6 with lymphoblastic leukemia. Complete remissions were observed in two of eight ANLL patients refractory to cytarabine, anthracycline, and m-Amsa (amsacrine), indicating a lack of cross-resistance between these drugs and Idarubicin. The median duration of remission was 8 weeks. The main major toxicity of Idarubicin therapy, severe myelosuppression, cannot be considered a toxic effect because it was desired in this case list. Our preliminary results indicate that Idarubicin has significant activity against refractory adult acute leukemia.

Acute Disease↗

Expression and modulation of common acute lymphoblastic leukaemia antigen by B prolymphocytic leukaemia cells.

Leukaemic blood lymphocytes from patients with B prolymphocytic leukaemia express the common acute lymphoblastic leukaemia antigen (CALLA). The in vitro incubation of prolymphocytes with leucocyte conditioned medium produced the acquisition of plasma cell morphology, of intracytoplasmic immunoglobulins and the simultaneous reduction of CALLA expression. The presence of CALLA appears to be unrelated to different clinical courses. Our report demonstrates that the antigen is present also in relatively mature stages of B lymphocyte differentiation. The blastic appearance of prolymphocytes could suggest that CALLA may be related to active metabolism or function of these cells.

Antigens, Neoplasm↗

Massive chemotherapy with non-frozen autologous bone marrow transplantation in 13 cases of refractory Hodgkin's disease.

A group of 13 patients with advanced, diffuse Hodgkin's disease, poorly responding to the most widely employed primary chemotherapy regimens, were treated with massive chemotherapy (MCH) followed by rescue with non-frozen autologous bone marrow infusion (ABMT). Complete remission (CR) was obtained in 8/13 patients (61.5%) and partial remission in two. Hematopoietic recovery occurred in 12 cases. These preliminary results would seem to indicate that MCH with non-frozen ABMT may be successfully used in patients with resistant or relapsed Hodgkin's disease.

Adolescent↗

Lymph node immunohistology in intravenous drug abusers with persistent generalized lymphadenopathy.

Lymph node biopsy specimens from 16 intravenous drug abusers with persistent generalized lymphadenopathy were evaluated by immunohistochemical methods using a panel of antisera to detect different cell populations. The 11 cases that we tested on cryostat sections showed an increased number of Leu-2a-positive cells (cytotoxic-suppressor phenotype) in the follicular centers and a significantly reduced helper-to-suppressor T-cell mean ratio when compared with control tissues. In these 11 patients the peripheral helper-suppressor ratio was at the lower normal limit or inverted. Ten cases tested for anti-human T-cell lymphotropic virus type III antibodies were positive. In all 16 cases, immunohistology of paraffin-embedded sections demonstrated a polyclonal B population; 12 of 15 patients tested had polyclonal hypergammaglobulinemia, mostly IgG. The mixed-cell population of the lymph node sinuses was composed mostly of Leu-M1-positive and lysozyme-positive cells and, to a lesser extent, by alpha 1-antichymotrypsin-positive and S100 protein-positive cells. It seems that many of the immunologic dysfunctions found in these patients appear to be reflected in a fairly repetitive immunohistologic pattern.

Acquired Immunodeficiency Syndrome↗

Influence of sialic contents on the chemiluminescent response of human leucocytes to group B streptococci.

The sialic acid content in reference strains of various Group B streptococci serotypes was studied before and after serial passages in mouse to enhance the virulence. The passages in mouse strongly increased the sialic acid content but the neuraminidase treatment reduced the to comparable values in reference and in virulent strains. The chemiluminescent response of human polymorphonuclear leucocytes to different GBS strains was higher for reference strains and lower for virulent strains. Sialic acid removal by neuraminidase increased the chemiluminescent response in virulent and in reference strains. Negative correlation between sialic acid content and chemiluminescence was demonstrated in strains of the same serotype, before and after passages in mouse and neuraminidase treatment for types Ic, II and III but no correlation was found considering the sialic acid content in strains belonging to different serotypes.

Animals↗

[Detection of bacteremia by biphasic and radiometric methods].

During one year period our laboratory carried out 859 hemocultures. These have been evaluated with two methods: a conventional biphasic method (Castaneda bottles), and the automated radiometric method (Bactec System). 185 cultures were obtained with one or both methods. Of these 3.5% were considered contaminated, therefore the clinically significant isolation rate was 16.2%. Of these 86.4% was recovered by biphasic system and 79.8% by Bactec System. The recovery time to positivity and spectrum of isolates were similar for the two methods. Although there were substantially more contaminants isolated in the Vacutainer-Bactec System.

Bacteriological Techniques↗