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M Santamaria

Publications and source records attributed to M Santamaria.

At least 37 records · Page 2Linked to original sources
PubMed1992

The activation antigen CD69 is selectively expressed on CD8+ endomyocardium infiltrating T lymphocytes in human rejecting heart allografts.

We analyzed the presence of T-cell subsets (CD4/CD8) and the activation markers CD25 and CD69 in the cellular infiltrates of endomyocardium biopsies taken from transplanted human hearts. The results indicate that CD25 was present within specimens mainly infiltrated by CD4+ cells. In contrast, CD69 was found in infiltrated biopsies by CD8+ cells, as determined by single immunofluorescence. Double immunoenzymatic staining was used to investigate the cellular distribution of the activation markers studied in some representative cases. Thus, CD25 was found on both CD4+ and CD8+ cells while CD69 molecule was selectively expressed on CD8+ T-cell subset. These results suggest that CD69 is a surface molecule relevant to the CD8+ cell-mediated graft rejection events of allografted human hearts.

Antigens, CD↗
PubMed1992

HPV types in women with normal cervical cytology.

PCR-based hybridization methods have been used to show that some women with normal cytology are carriers of HPV DNA of the types strongly related to cervical cancer. How these women should be managed remains unclear. This chapter selectively reviews reports which have estimated type-specific HPV prevalence in relation to the presence or absence of morphological signs of HPV infection. Overall, these reports indicate that among women who were identified as carriers of HPV DNA (by PCR-based methods) and who also had a normal cytological smear, the HPV type detected in the majority of instances was a high-risk viral type for cervical cancer (HPV types 16/18 = 44.7%; HPV types 31/33/35 = 8.1%; other and unknown types = 37.9%). This suggests that screening programmes which include PCR-based HPV detection could reduce the false negative rates currently reported by screening programmes based on cytology alone.

Adult↗
PubMed1990

The reaction of CN- with the binuclear copper site of Neurospora tyrosinase: its relevance for a comparison between tyrosinase and hemocyanin active sites.

The equilibrium and the kinetics of the reaction between Neurospora crassa tyrosinase and cyanide have been studied. Cyanide reacts with the binuclear copper active site of the protein competitively with respect to dioxygen and displaces the metal ions. This process occurs stepwise and involves transient intermediates containing mononuclear Cu(I) sites. The reaction mechanism proved to be the same as described earlier for molluscan and arthropodan hemocyanins, which share with tyrosinase the same copper active site organization, but perform different physiological functions. A comparison of the kinetic parameters between the different proteins shows that the tyrosinase copper active site has a greater accessibility than that of hemocyanin. The relevance of these data in terms of structure-function relationship and evolution of the binuclear copper proteins is discussed.

Binding Sites↗
PubMed1989

The effect of calcitriol on natural killer cell activity in hemodialyzed patients.

We report the effect of calcitriol on natural killer (NK) cell activity in patients with chronic renal failure undergoing long-term hemodialysis. Natural killer cytotoxicity was significantly decreased in these patients when compared to healthy control subjects (13.1 +/- 1.3 vs 38.8 +/- 2.4%, P less than 0.001). These patients also have decreased levels of calcitriol (17 +/- 3 vs 36 +/- 3 pg/ml, P less than 0.001). After 14 days of oral treatment with calcitriol at a dose of 0.5 micrograms per day, a significant increase in NK activity was observed (20.2 +/- 1.6%, P less than 0.001). This increase was maintained after 28 days of treatment (21.1 +/- 2%, P less than 0.001). These results suggest that the decreased serum calcitriol might contribute to the diminished NK activity found in hemodialyzed patients, and suggests a new potential therapeutical utility of calcitriol as modulator of the immune function in these patients.

Adult↗
PubMed1988

Identification and characterization of a human cell line with dendritic cell features.

CORP-4 is a cell line obtained in our laboratory from an explanted human bladder carcinoma. This cell line shows certain dendritic cell features such as adherence to the culture plate surface, a doubling time of 24 h and an enzymatic profile typical of cells involved in antigen presentation (non-specific esterases, lysozyme and alpha-1-antitrypsin). Its phenotypic analysis revealed CD 15 and Fc receptor expression, S-100 surface protein and the presence of positive reactivity to different lectins such as Concanavalin A (Con A) and Peanut agglutinin (PNA). CORP-4 was found to be a non-phagocytic cell line after it was assayed with latex, and FcR- and C3bR-mediated phagocytosis. Furthermore, CORP-4 produced interleukin-1 (IL-1) as determined by thymocyte proliferation assays and also fixes immune complexes in a non-complement dependent fashion. HLA class I and class II antigens were inducible by both 5 azacytidine and gamma interferon.

Agglutination Tests↗
PubMed1988

Effects of anions, Ca2+, Mg2+, and aliphatic alcohols on the reaction of hemocyanin with cyanide.

The reaction between Carcinus maenas hemocyanin and cyanide has been used for probing protein conformation in the presence of perturbants such as various anions, cations (Ca2+, Mg2+), and aliphatic alcohols. The kinetic parameters of the reaction are strongly affected by these agents, suggesting that the induced conformational modifications change the reactivity of the active site toward exogenous ligands. Different patterns are observed according to the perturbant used. As indicated by the mathematical treatment of the kinetic curves the affinity of the active site for CN- and O2 is affected much more than the rate constant of copper removal.

1-Propanol↗
PubMed1988

Expression of sialylated Leu-M1 antigen in histiocytosis X.

The purpose of this study is to determine the versatility of the monoclonal antibody anti-Leu-M1 in histiocytosis X diagnosis. This antibody recognizes an unsialylated lacto-N-fucopentaose III (hapen X) carbohydrate moiety that is linked to the cell membrane protein in interdigitating reticulum cells and Langerhans' cells. Previously, the authors have shown that anti-Leu-M1 can be used to stain Reed-Sternberg cells, which are likely related to interdigitating reticulum cells. In this study, the authors tested the usefulness of anti-Leu-M1 in staining formalin-fixed and paraffin-embedded tissue sections from eight patients with histiocytosis X. For staining of histiocytosis X cells, unlike Reed-Sternberg cells in Hodgkin's disease, neuraminidase treatment was required for removal of sialic acid residues from the Leu-M1 antigen. The staining characteristics of anti-Leu-M1 in histiocytosis X cells resembled those of normal Langerhans' cells and lymphocyte and histiocyte variants (L & H cells) in the lymphocyte-predominant type of Hodgkin's disease. The significance of sialylation of Leu-M1 antigen in histiocytosis X cells has yet to be determined in order to correlate the prognosis of the disease. The authors suggest that anti-Leu-M1 used together with neuraminidase treatment is a valuable tool in the diagnosis of histiocytosis X when electron microscopy or frozen sections for OKT6 immunostaining are not available.

Adult↗
PubMed1987

Pulmonary hyperinflation and emphysema in infants with the Marfan syndrome.

The Marfan syndrome is a dominantly inherited disorder of type I collagen with well recognized skeletal, cardiac and ophthalmological manifestations. Less recognized are the pulmonary manifestations of the disease. Although chronic pulmonary emphysema, interstitial lung disease with honey combing and spontaneous pneumothorax have been sporadically reported, there is no documentation of these abnormalities in the radiological literature. We describe the clinical and radiographic findings in the lungs of four infants with Marfan's syndrome and provide pathologic correlation from autopsy specimens of two of these patients. In addition, we have updated the literature describing the pulmonary abnormalities of this still obscure disorder.

Humans↗
PubMed1987

Transplacental hemorrhage associated with placental neoplasms.

We report a case of choriocarcinoma in situ arising from a term placenta in an otherwise normal pregnancy that resulted in fetal hydrops and intrauterine fetal death from chronic fetal-maternal hemorrhage (FMH). The clinical and pathologic features are described and compared with the few similar cases reported and with an additional placental choriocarcinoma found in our files. We also describe the clinical and pathologic observations of two chorangiomas that caused massive FMH and led to fetal death.

Adult↗
PubMed1985

Hepatitis B virus markers in children with acute leukemia: the effect of chemotherapy.

Hepatitis B virus markers were tested in the serum of 49 children with acute leukemia on clinical presentation and during subsequent chemotherapy. Hepatitis B surface antigenemia was observed in only six patients (12%), none of whom progressed to chronic infection. Chemotherapy had a marked suppressive effect on the production of antibodies to hepatitis B virus antigens and overt infection occurred in two children after suppression of protective immunity. Evidence of liver damage was frequently observed and was largely independent of serologic data. These results indicate that active immunization with hepatitis B vaccine may not find a clear place in this clinical setting.

Acute Disease↗
PubMed1985

Acute and chronic hepatitis in childhood leukemia: a multicentric study from the Italian Pediatric Cooperative Group for Therapy of Acute Leukemia (AIL-AIEOP).

The incidence of acute and chronic liver damage and its relation to hepatitis B virus (HBV) infection was evaluated in 164 consecutive children with acute leukemia seen in ten Italian hemato-pediatric units. Thirteen out of 164 children (7.9%) had acute hepatitis (AH) during treatment, while 8/90 (8.8%) showed an acute exacerbation of liver damage within 6 months after therapy withdrawal. Seven of the 13 children with AH while on therapy were HBsAg positive. In 12/13 cases, liver disease progressed to chronicity. Five of eight children who developed AH after completion of treatment were HBsAg positive. Eighty-nine patients (54.2%) developed biochemical evidence of chronic hepatitis during therapy; 48/89 were followed after cessation of treatment and 33 of them showed persisting evidence of liver cell necrosis. Thirty-three out of 133 children (24.8%) tested for serum HBsAg were found positive: 26 (78.7%) of them developed chronic hepatitis. Sixty-four out of 133 patients were evaluated after cessation of treatment: Chronic hepatitis persisted in 16/22 HBsAg-positive (72.7%) and in 17/42 HBsAg-negative (40.4%) children during follow-up. The outcome of these liver diseases after treatment withdrawal did not differ significantly in relation to HBV serology, suggesting that viral rather than toxic agents were responsible for liver damage also in most HBsAg-negative patients. The high incidence of chronic HBV infection in children with leukemia found in this multicentric study could suggest a need for active immunization with HBV vaccine, but the efficacy of such approach in this clinical setting is still to be validated.

Acute Disease↗
PubMed1985

Corynebacterium group D2 as a cause of alkaline-encrusted cystitis: report of four cases and characterization of the organisms.

In four patients with alkaline-encrusted cystitis, Corynebacterium group D2 was isolated from consecutive urine cultures and stones. Encrusted cystitis occurred in bladders harboring inflammatory or tumorous lesions in patients with chronic or recurrent urinary tract infections appearing after surgery or instrumentation. The urease activity of Corynebacterium group D2 and the neutralization of this enzyme by acetohydroxamic acid are shown. Clinical improvement, disappearance of struvite crystals, and decrease of the urine pH were obtained when these bacteria were eliminated from urine samples. Corynebacterium group D2 strains were highly resistant to many antimicrobial agents but were highly susceptible to norfloxacin and vancomycin when tested at two pHs (7.4 and 8.5).

Aged↗
PubMed1984

The neuroectodermal tumor of bone.

Four small round cell malignant tumors of bone occurring in children are described. There was no catecholamine secretion and the clinical, radiologic, and biopsy diagnosis in each was Ewing's sarcoma. Glycogen was sparse both on imprints and in tissue sections. The tumors, when extensively sampled, had areas of a lobular growth pattern and Homer Wright rosettes. The rosettes were always focal and varied in complexity from case to case; they were rudimentary in one instance and markedly fibrillar in the most obvious instance. Neuron-specific enolase was demonstrated in tissue sections and in longterm cell cultures from three of the tumors. The cultured cells put out moderately long beaded processes in serum-free medium but had no catecholamine fluorescence. Electron microscopy of the tumor rosettes and the cultured cells showed processes containing aggregates of microtubules and only one case had rare neurosecretory granules. This study suggests that some small round cell tumors of bone and soft tissue in children, which present as Ewing's sarcoma, are neuroectodermal in nature.

Bone Neoplasms↗
PubMed1984

Segmental staining of the murine nephron by monoclonal antibodies directed against the GP-2 subunit of laminin.

Monoclonal antibodies to GP-2, the 220,000-dalton subunit of laminin, were used in an immunohistologic study to investigate structural variations in basement membranes. Mouse kidney was used because of the wide range of basement membranes represented. Two rat/mouse monoclonal antibodies, designated LAM-I and LAM-II were compared with rabbit polyclonal anti-GP-2 in a light and electron microscopic study that identified nephron segments by morphology, by topography, and by the use of markers specific for individual segments. LAM-I staining is demonstrable on all tubular and glomerular basement membranes but not on those of blood vessels or smooth muscle, differing in this respect from anti-GP-2. LAM-II staining is confined to the basement membranes of the convoluted portion of proximal tubule segments (S1 and S2), not the straight (S3) portion; to the thin limb and the thick ascending limb of Henle's loop, but not distal convoluted tubules or collecting ducts. The heterogeneity of GP-2 localization may be due to differing conformations of the molecule at these sites.

Animals↗