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Biomedical subjects

L M Larocca

Publications and source records attributed to L M Larocca.

At least 73 records · Page 4Linked to original sources
PubMed1995

Evaluation of cerebrospinal fluid EBV-DNA and IL-10 as markers for in vivo diagnosis of AIDS-related primary central nervous system lymphoma.

Acquired immunodeficiency syndrome (AIDS)-related primary central nervous system lymphoma (PCNSL) is almost always associated with the Epstein-Barr virus (EBV), and EBV-DNA in cerebrospinal fluid (CSF) has been indicated as a useful tumour marker for this HIV-related neoplasm. AIDS lymphomas also show an enhanced production of IL-10 which is generally associated with the presence of EBV in lymphoma cells. We performed a prospective study in 19 HIV seropositive patients with brain mass lesions, and in 21 other AIDS patients with or without other neurological disorders, to assess the in vivo diagnostic value of EBV-DNA and of IL-10 levels in the CSF for primary lymphoma of the central nervous system (CNS). EBV-DNA was detected by a nested polymerase chain reaction (PCR) in the CSF from seven of eight patients with PCNSL, diagnosed by brain biopsy (87.5% sensitivity) and in none of the 11 controls with brain mass lesions (100% specificity) and of the other 21 AIDS patients with or without neurological disorders. The only patient with PCNSL without detectable EBV-DNA in the CSF was also negative for EBV-DNA in the lymphoma tissue, whereas the samples of the other seven brain lymphomas were all positive for EBV-DNA by nested PCR. Therefore 100% of patients with an EBV-positive primary CNS lymphoma had detectable EBV-DNA in the CSF. No patient from the control group without PCNSL with EBV-negative CSF developed a lymphoma after a mean follow-up of 157 +/- 173 d. IL-10 levels in the CSF from the patients with PCNSL were not significantly different from those in the other groups of patients with AIDS. Due to uniformly high levels in the CSF from AIDS patients, IL-10 is not a useful diagnostic marker for AIDS-related brain lymphoma. The detection of EBV-DNA from the CSF by nested PCR is an extremely sensitive and specific diagnostic tool for AIDS-related PCNSL and should be further evaluated as a possible alternative in patients from whom brain biopsy is not advisable.

Adult↗
PubMed1994

Growth-inhibitory effect of quercetin and presence of type II estrogen binding sites in primary human transitional cell carcinomas.

Eight cases of transitional cell carcinoma (TCC) of the bladder were investigated for the presence of estrogen receptors (ER) and Type II estrogen binding sites (Type II EBS). All these tumors specifically expressed type II EBS, while only 3 of 8 cases contained low amounts of ER. All the cases assayed for the presence of both nuclear and cytoplasmic type II EBS revealed the presence of these binding sites in the two compartments. Both cytoplasmic and nuclear receptors were similar to type II EBS described in other tissues relative to their binding specificity for estrogens and quercetin and their sensitivity to reducing agents. Quercetin, 10 microM., was effective in inhibiting in vitro bromodeoxyuridine (BrdUdR) incorporation by TCC cells. Rutin, which bound little if any to type II EBS, did not show any inhibitory effect on in vitro BrdUdR incorporation by tumor cells, suggesting a type II EBS mediated effect of flavonoids. Although the mechanism of the antiproliferative activity of quercetin remains to be fully clarified, the possible therapeutic potential of quercetin and related flavonoids should be considered.

Aged↗
PubMed1994

Detection of growth hormone-producing cells in human thymus by immunohistochemistry and non-radioactive in situ hybridization.

It is well recognized that growth hormone (GH) may act as a growth and differentiation factor for the thymus gland. Recently, it has been reported that Pit-1/GHF-1 transcription factor, which controls the expression of both GH and prolactin, is expressed in stromal (not lymphoid) cells of human thymus. Here, we demonstrated by immunohistochemistry and in situ hybridization the presence of distinct GH-producing epithelial cell subsets in human thymus. The cells positive for GH mRNA and GH-immunoreactive substance are both located in the same thymus compartments, i.e., along the thymus capsule, in the subcapsular cortex, and within the septa. Local concentration of GH higher than systemic ones, in combination with other factors, may be important in regulating the thymic microenvironment necessary for T-lymphocyte differentiation.

Child, Preschool↗
PubMed1993

Type II estrogen binding sites and antiproliferative activity of quercetin in human meningiomas.

Eleven cases of meningiomas were investigated for the presence of estrogen and progesterone receptors. These tumors specifically bound estradiol. This binding activity almost exclusively resulted from the presence of high numbers of type II estrogen binding sites (EBS). Estrogen receptors were absent or present at low concentrations. Competition analysis showed that the flavonoid, quercetin, competed for tritiated estradiol binding to type II EBS; both rutin and hesperidin did not. In addition, 10 microM quercetin, unlike rutin or hesperidin, was effective in inhibiting in vitro bromodeoxyuridine incorporation by meningioma cells. Although the mechanism of the antiproliferative activity of quercetin remains to be clarified, it is possible that this flavonoid may regulate cell growth through a ligand interaction with type II EBS.

Adult↗
PubMed1992

Growth-inhibitory effect of quercetin and presence of type-II estrogen-binding sites in human colon-cancer cell lines and primary colorectal tumors.

We studied the effect of quercetin (Q) on the proliferation of HT-29, WiDr, COLO 201, and LS-174T human colon cancer cell lines. Q, between 10 nM and 10 microM, exerted a dose-dependent, reversible inhibition of cell proliferation. Cell-cycle analysis revealed that the growth-inhibitory effect of Q was due to a blocking action in the G0/G1 phase. Using a whole-cell assay with 17 beta-[3H]-estradiol as tracer, we demonstrated that all these cell lines contain type-II estrogen-binding sites (type-II EBS). By using Q and other chemically related flavonols (3,7-4'-trimethoxyquercetin, 3,7,3',4'-tetramethoxyquercetin, kaempferol, morin, and rutin), we observed that the affinities of these compounds for type-II EBS are correlated with their growth-inhibitory potential. Furthermore, the Q sensitivity of the colon cancer cell lines was correlated with the number of type-II EBS/cell. Then Q could regulate colon cancer cell growth through a binding interaction with type-II EBS. This mechanism could also be active in vivo as we have observed that cytosolic type-II EBS are present in primary colorectal cancers and that Q is effective in inhibiting the in vitro bromodeoxyuridine incorporated by neoplastic cells in these cancers.

Adenocarcinoma↗
PubMed1991

Apparent isolated skin relapse in acute monocytic leukemia. A case report.

A case of acute monocytic leukemia with an apparent isolated skin relapse is reported. The cutaneous involvement was associated with a morphological bone marrow remission but a cytogenetic relapse was present. Regression of the skin lesions was obtained with a protocol including daunoblastine, aracytin and thioguanine, but the patient relapsed and died a few months later without achieving another remission. The relation between cutaneous and medullary disease is discussed.

Adult↗
PubMed1991

Detection of mRNA and hnRNA using a digoxigenin labelled cDNA probe by in situ hybridization on frozen tissue sections.

A full-length cDNA clone encoding the constant region of T cell receptor beta chain was labelled by random priming DNA with digoxigenin-dUTP. The probe was used to estimate the relative amount of the receptor beta chain mRNA by in situ hybridization on frozen sections from human thymus and lymph nodes. The hybridization was visualized in blue using an anti-digoxigenin antibody conjugated with alkaline phosphatase and a subsequent enzyme-catalysed colour reaction. The distributions of the signal in tissue sections were as expected. Moreover, labelled cells showed hybrids both in the cytoplasm and in the nucleus, and strongly and weakly stained cells were clearly distinguishable. The results indicate that this method of in situ hybridization should be useful in the detection of specific mRNA in frozen sections.

Child, Preschool↗
PubMed1991

Antiproliferative activity of quercetin on normal bone marrow and leukaemic progenitors.

We used an in vitro clonogenic assay in semi-solid medium to test the sensitivity of normal bone marrow and acute myeloid and lymphoid leukaemia progenitors to the flavonol quercetin. We have studied 14 acute myeloid (AML) and four acute lymphoid (ALL) leukaemias. All ALL and the vast majority of AML (12/14) had a high sensitivity to quercetin with more than 50% growth inhibition at 2 x 10(-6) M quercetin. One M3-AML was partially quercetin-sensitive displaying 60% surviving AML-colony forming units (CFU-AML) at a quercetin concentration of 10(-5) M. One M1-AML was resistant to the growth inhibitory effect of quercetin at a concentration of 2 x 10(-5) M. The clonogenic efficiency of both AML and ALL positively correlated with leukaemic colony-forming unit (CFU-L) sensitivity to quercetin suggesting that this parameter can be useful in predicting quercetin responsiveness of leukaemic cells. We have also studied the effect of various quercetin concentrations on colony formation by normal bone marrow cells. At a quercetin concentration of 10(-5) M, we observed (in five different experiments) a mean recovery of 53% and 65% of erythroid blast-forming units (BFU-E) and granulocyte-macrophage colony-forming units (CFU-GM), respectively. Thus, normal bone marrow appeared partially resistant to quercetin, being inhibited less than 50% by quercetin concentration higher than 2 x 10(-5). When normal bone marrow were deprived in CD34+ haematopoietic progenitors the resultant population became highly sensitive to quercetin, with a mean recovery of BFU-E and CFU-GM of 5% and 12% of controls respectively in the presence of 2 x 10(-5) M quercetin. Furthermore, CD34 progenitors, positively selected, appeared fully resistant to quercetin concentrations as high as 2 x 10(-5) M. Thus, CD34+ progenitors are a quercetin-resistant component in normal bone marrow. In conclusion, our results further provide a biological basis for the therapeutic use of quercetin, considering that this compound could inhibit leukaemic cell growth without suppressing normal haematopoiesis.

Acute Disease↗
PubMed1990

Type-II estrogen binding sites in a lymphoblastoid cell line and growth-inhibitory effect of estrogen, anti-estrogen and bioflavonoids.

Type-II estrogen-binding sites (type-II EBS) have been demonstrated in the human lymphoblastoid cell line IM-9 using a whole-cell assay with (6,7-3H) estradiol (3H-E2) as tracer. Competition analysis showed that the anti-estrogen tamoxifen and the flavonoids quercetin and rutin competed for (3H)-E2 binding to type-II EBS. Growth experiments demonstrated that diethylstilbestrol (DES) tamoxifen (TAM), quercetin and rutin exerted a reversible dose-dependent inhibition of cell proliferation in the range of concentrations between 10 nM and 10 microM. The relative binding affinity of quercetin, rutin, DES and TAM for type-II EBS correlated well with their potency as cell growth inhibitors. Moreover, hesperidin, a flavonoid which does not bind to type-II EBS, was ineffective in inhibiting cell growth. Cell-cycle analysis showed that the growth-inhibitory effect of DES, TAM or quercetin was due to a blocking effect in the G0-G1 phases. Our results suggest that high estrogen and anti-estrogen concentrations and flavonoids may regulate IM-9 cell growth through a common mechanism involving a binding interaction with type-II EBS.

Binding, Competitive↗
PubMed1990

Intrathymic deficient expansion of T cell precursors in Down syndrome.

To correlate the intrinsic cellular immunodeficiency, which is a major cause of increased susceptibility to polytopic infections in Down syndrome (DS) patients, with the histologic abnormalities observed in the thymus of these patients, we have studied thymus fragments and thymocyte cell suspensions from 15 non-institutionalized DS subjects. Comparing to the control age-matched samples, a reduced thymic cortex and a distinct depletion of CD1-positive (+) cells was observed by immuno-histologic examination. The phenotypic analysis of unselected thymocytes showed a significant reduction of CD3+, CD1+, CD4+, and CD8+ cells. When the total thymocyte population was separated into 10 fractions, using a continuous Percoll density gradient, a difference in cell distribution was observed. DS thymuses are almost devoid of high-density thymocytes (fractions 6-9) while more than 75% of the cells were recovered in the lightest 3 fractions (Frs). In addition, these thymuses were characterized by a marked depletion of CD1+ cells and by a conspicuous reduction of CD3+ cells normally present in the high-density Frs. On the other hand, the lightest 3 Frs of DS subjects were enriched in low-density CD1+ cells. Although enriched in these cells, normally characterized by a high mitotic activity, Fr1 DS thymocytes showed a reduced spontaneous proliferative capacity. When the expression of T cell receptor alpha- and beta-subunits was studied, the percentages of cells stained with anti-alpha and anti-beta antisera were found to be reduced in DS unfractionated thymocytes. The reduced number of high-density CD1+ thymocytes associated with a reduced spontaneous proliferative activity of low-density CD1+ thymocytes suggests that in DS thymuses there is a deficient expansion of immature T cells, resulting in a reduction of the various thymocyte subpopulations, including the thymocyte pool which differentiates into functionally mature T cells expressing the alpha-beta T cell receptor.

Child, Preschool↗
PubMed1990

Morphological and immunohistochemical study of Down syndrome thymus.

The incidence and severity of various histologic changes were studied in the thymuses from 35 Down syndrome (DS) patients. Variable histologic alterations up to fibrotic involution of the gland were found. In addition, immunohistochemical investigation showed a reduction or absence of interdigitating reticulum cells roughly correlated with the severity of morphologic changes. The complex architectural and cellular thymic alterations, concerning both cortical and medullary microenvironment, could be correlated with the imbalances of immunity in DS patients.

Child, Preschool↗
PubMed1990

Immunocytochemical distribution of S-100 protein in patients with Down's syndrome.

The immunohistochemical distribution of S-100 beta protein in patients with Down's syndrome was investigated as part of a study aimed at ascertaining a possible involvement in the syndrome (trisomy 21) of this protein, which has recently been shown to be coded in chromosome 21. No appreciable differences in the cell distribution of the antigen could be observed between patients with Down's syndrome and normal subjects. The possibility of an overexpression or abnormal expression of the molecule as a consequence of chromosome 21 triplication, not detectable by immunocytochemical methods alone, remains to be investigated.

Child, Preschool↗
PubMed1990

Neuropeptide-immunoreactive cells in human thymus.

The outer cortex of the human thymus contains a one- to two-cell-thick layer that is immunoreactive with antisera against beta-endorphin, (Leu)- and (Met)-enkephalin, bombesin, and substance P. The epithelial nature of these immunostained cells is revealed by immunoelectron microscopic studies showing the presence of desmosomal junctions. The presence of peptide-containing cells in the outer cortex, where the most immature and recently immigrated thymocytes are found, emphasizes the role of neuropeptides in regulating the microenvironment for T cell development.

Cell Differentiation↗
PubMed1990

Inhibitory effect of quercetin on OVCA 433 cells and presence of type II oestrogen binding sites in primary ovarian tumours and cultured cells.

We investigated the effect of the flavonoid quercetin (Q) on the proliferation of the ovarian cancer cell line OVCA 433. Growth experiments demonstrated that Q exerted a reversible dose-dependent inhibition of cell proliferation in the range of concentrations between 10 nM and 10 microM. Two other flavonoids tested, rutin and hesperidin, were ineffective in inhibiting cell growth. Cell cycle analysis showed that the growth inhibitory effect of Q was due to a blocking effect in the GO/G1 phase. Using a whole cell assay with (6.7-3H) oestradiol (3H-E2) as tracer we demonstrated that OVCA 433 cells contain type II oestrogen binding sites (type II EBS). Competition analysis showed that Q competed for 3H-E2 binding to type II EBS while both rutin and hesperidin did not. Appreciable amounts of type II EBS were also detected in seven primary ovarian tumours. Our results suggest that Q may regulate ovarian cancer cell growth through a mechanism involving a binding interaction with type II EBS. This mechanism could also be active in vivo since primary ovarian tumours contain type II EBS.

Cell Division↗