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Biomedical subjects

A Poletti

Publications and source records attributed to A Poletti.

At least 109 records · Page 6Linked 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↗

Enzyme- and immunohistochemical study of a case of histiocytic necrotizing lymphadenitis.

A combined morphological, immunohistological, and enzyme histochemical analysis was performed on frozen and fixed lymph node tissue in a case of histiocytic necrotizing lymphadenitis (HNL) using conventional histology, a panel of monoclonal and polyclonal antibodies, and a series of common haematological enzyme reactions. Histology showed multiple paracortical necrotizing foci which, in a prominently necrobiotic background devoid of granulocytes, contained large numbers of foamy histiocytes and macrophages intermingled with cells resembling degenerating plasmacytoid T-cells. Most of the histiocytes were alpha1-antichymotrypsin positive and foamy cells were also distinctly Leu-M1 positive. Strong granular acid phosphatase (AP) positivity was present in the cytoplasm of the macrophages and histiocytes. The cells with plasmacytoid features showed weaker and homogeneously diffuse AP staining. Alpha-naphthyl acetate esterase (ANAE) activity was much less striking than AP in the necrotizing foci and most of the ANAE negative cells corresponded to those with plasmacytoid features. No cells with B-cell lineage markers were present within the necrotizing foci; most of the occasional T-cells (Leu-1+, Leu-4+) present in the foci were Leu-2a+ (OKT8+) whereas OKT10+ lymphoid cells were abundant and appeared to correspond with the cells with plasmacytoid features. Our combined data confirm that the special type of necrosis found in HNL develops within foci of plasmacytoid T-cells undergoing regressive changes and apparently exhibiting distinct immunohistological and enzyme histochemical features.

Adult↗

A histopathologic study of persistent generalized lymphadenopathy in intravenous drug abusers.

Persistent generalized lymphadenopathy (PGL) has been reported in groups at risk for the acquired immunodeficiency syndrome including intravenous (iv) drug abusers. We investigated the histology of the lymph node biopsies obtained from 18 iv heroin abusers. All the patients (13 males and 5 females; median age 23.5) had generalized lymphadenopathy. This was associated with one or more systemic symptoms in 72% of the cases. Immunologic abnormalities were present in most of the patients. The overall histological picture consisted of a fairly repetitive pattern dominated by an exuberant and diffuse hyperplasia of frequently misshapen and poorly outlined follicles, associated with a striking proliferation of capillary vessels and a very consistent amount of plasma cells both extending in the follicular and interfollicular areas. Multinucleated giant cells of the Warthin-Finkeldey type ("mulberry cells") were encountered in 22% of the cases. It would appear that in the follicular district the most indicative diagnostic clues of PGL can be obtained if one considers the abnormal morphology of the follicles associated with a consistent presence of plasma cells and a scattered fine network of proliferating capillary vessels.

Adult↗

Neuropsychological deficits in arterial hypertension.

Sixty subjects with uncomplicated essential hypertension and 60 matched normal subjects were submitted to neuropsychological tests in order to establish whether some impairment of cognitive functions can be evidenced even in those hypertensive subjects that are in this respect asymptomatic on standard examination and interview. The hypertensive subjects obtained significantly poorer results than normotensive subjects on memory, visuo-motor and performance tests. In the control group, the classic negative correlation pattern between age and scores was observed, while in the patient group this correlation could be confirmed only in a few tests. Subgrouping of patients according to hypertension duration and treatment showed that the impairment of cognitive functions manifested itself very early and did not tend to progress within 6-10 years of hypertension duration.

Adolescent↗

The Italian experience in mental health care.

Italy's Law 180, passed in 1978, abolished mental hospitals and replaced them with community services. The Italian literature suggests that the law has been far less successful in improving services for mental patients than reports by foreign visitors have indicated. The authors visited Italy on two occasions in 1984 and 1985 to assess for themselves the impact of the law. In many parts of the country hospitals were still open but badly understaffed and physically deteriorated; in Trieste, where the reform movement started, there was a good system of services, but a hospital whose closing had been publicly celebrated still housed several hundred patients. The authors describe the social and political climate in which Law 180 was passed, discuss the central role of Franco Basaglia and his Psichiatria Democratica movement, summarize the findings of their two visits, and attempt to explain why members of Psichiatria Democratica consider hospitals that remain open to be closed.

Aged↗

The 'Italian Experience' reconsidered.

Our analysis of the problems of the Italian psychiatric services has drawn a lively correspondence challenging our findings. In September 1985, we undertook a second study tour in Italy. This is now reported, with notes on specific criticisms of the earlier paper.

Community Mental Health Centers↗

S-100 protein immunostaining in cells of dendritic morphology within reactive germinal centers by ABC immunoperoxidase method.

The "dendritic" and the "interdigitating" (IRC) reticulum cells are commonly reported to have different topographical distribution in the human lymphoid tissue and some peculiar cytochemical and immunohistochemical features. These include the detection of S-100 protein by PAP (peroxidase anti-peroxidase) method only in IRC located in the thymus-dependent areas. In 15 reactive lymphoid tissue specimens (11 lymph nodes, 3 tonsils, and 1 adenoid) the presence of S-100 protein was tested by ABC (avidin-biotin complex) immunoperoxidase method. IRC were constantly positive. Other positive cells were located within the follicular germinal centers; these immunostained cells appeared as a striking network composed of dendritic-shaped processes displaying a finely granular positivity for S-100 protein. It is suggested that by using this very sensitive technique, S-100 protein can also be detected in intrafollicular cells of dendritic morphology.

Avidin↗

Demonstration of S-100 protein distribution in human lymphoid tissues by the avidin-biotin complex immunostaining method.

Immunoreactivity for S-100 protein was investigated immunohistochemically in a series of 49 fixed and paraffin-embedded normal, reactive, and neoplastic human lymphoid tissue specimens. The avidin-biotin complex immunoperoxidase method was used, with overnight (12-hour) incubation with a commercially available antiserum to S-100 protein. In addition, cryostat sections were tested with DRC 1 monoclonal antibody to dendritic reticulum cells (DRCs) in three cases and with OKT6 antibody to interdigitating reticulum cells (IRCs) in nine cases. All tissues, including lymph nodes, tonsils, adenoid, spleens, appendices, thymuses, and tissues containing nodular reactive lymphoid infiltrates, demonstrated a consistent immune staining pattern. A striking network composed of dendritic processes that showed finely granular S-100 protein immunoreactivity was observed in most of the follicular germinal centers; a similar dendritic pattern was observed in the follicular centers when the corresponding frozen sections were immunostained with DRC 1. In the extrafollicular areas, the S-100-positive cells topographically and morphologically resembled the IRCs that were demonstrated by OKT6 antibody in the corresponding frozen sections. The results seem to indicate that cells topographically and morphologically similar to IRCs and DRCs in human lymphoid tissues from different sites share immunoreactivity for S-100 protein. The present study confirms the unexpected presence of S-100 protein in dendritic cells of follicular germinal centers by a simple and currently available method.

Antibodies, Monoclonal↗

Understanding the Italian Experience.

The "Italian Experience" in closing down mental hospitals has been highly praised by some British observers, who have seen lessons for Britain in the development of community care. However, it has been the subject of heated debate in Italy--and the policy is now to be reversed by law. Two questions arise: why have the claims been exaggerated? And why have they found such ready and uncritical acceptance in Britain?

Community Mental Health Services↗

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↗

CEA and ABO(H) in upper urinary tract transitional tumors.

The expressivity of carcinoembryogenic antigen CEA and ABO(H) isoantigens is studied in a group of 40 pelvic and ureteral transitional cell carcinomas. CEA was not shown to be a tumor marker since it is not found in all tumors whereas it is demonstrated in a case of cystic pyelitis. Nevertheless, it seems to be associated with certain prognostic morphologic markers, i.e., grading and vascular invasion. The ABO(H) isoantigens do not seem to be correlated with the prognosis; many advanced-stage and grade tumors showed, in fact, positivity for these isoantigens in most neoplastic cells. Association of histological techniques and immunohistochemical studies does not seem as useful in predicting the course of upper urinary tract transitional tumors as in bladder tumors.

ABO Blood-Group System↗

Dye-sensitized photo-oxidation of pig kidney Dopa decarboxylase.

The effects of irradiation of pig kidney Dopa decarboxylase by visible light absorbed by the intrinsic chromophore, pyridoxal-P, and by the externally added dyes, pyridoxal-P or proflavin, have been studied. In all cases inactivation was observed, even though to different extens, which seemed to be essentially correlated to tryptophanyl residues photodestruction. Kinetics of inactivation and oxidation of these amino acid residues revealed the presence of two distinct groups of tryptophan residues with different photooxidation rate constants. A different role for these classes of residues in the structure and function of Dopa decarboxylase has been suggested.

Amino Acids↗