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M DeLeon

Publications and source records attributed to M DeLeon.

8 recordsLinked to original sources
PubMed2000

Heat-shocked A20 lymphoma cells fail to induce degranulation of cytotoxic T lymphocytes: possible mechanism of resistance.

A20 lymphoma cells were subjected to heat shock for 2 h at 42 and 43 +/- 0.1 degrees C and then evaluated at 37 degrees C for sensitivity to lysis by intact allo-specific cytotoxic T lymphocytes (CTLs), perforin-containing granules isolated from CTLs, and Fas-mediated apoptosis. Heat shock at 42 degrees C caused little change in sensitivity of the lymphoma cell line to lysis by intact CTLs or their isolated cytotoxic granules, but caused increased sensitivity to Fas-mediated apoptosis. However, A20 cells shocked at 43 degrees C declined significantly in sensitivity to lysis by intact CTLs, while remaining very sensitive to perforin granules and to Fas-mediated apoptosis. Expression of the inducible heat shock protein was observed in A20 cells incubated at 43 degrees C, but not in those incubated at 42 degrees C, suggesting a role for heat shock proteins. Furthermore, A20 cells shocked at 43 degrees C did not provoke degranulation and secretion of granzymes by antigen-specific CTLs, although formation of CTL-target conjugates and levels of MHC class I molecules remained unchanged. These observations demonstrate that hyperthermia or febrile conditions may reduce susceptibility of target cells to CTL attack due to failure of antigen presentation and the inability of CTLs to recognize heat stressed targets, thus enabling targets to escape CTL attack.

Animals↗
PubMed1999

Uterine artery embolization for the treatment of uterine leiomyomata midterm results.

INTRODUCTION: The authors review their midterm experience with uterine artery embolization for the treatment of uterine fibroids. MATERIALS AND METHODS: Sixty patients were referred for permanent polyvinyl alcohol (PVA) foam particle uterine artery embolization during an 18-month period. Detailed clinical follow-up and ultrasound follow-up were obtained. RESULTS: Bleeding was a presenting symptom in 56 patients and pain was a presenting symptom in 47 patients. All patients underwent a technically successful embolization. One of the patients underwent unilateral embolization. Fifty-nine patients underwent bilateral embolization. Of all patients undergoing bilateral embolization, at last follow-up (mean, 16.3 months), 81% had their uterus and had moderate or better improvement in their symptoms. Ninety-two percent of these patients also had reductions in uterine and dominant fibroid volumes. Overall, the mean uterine and dominant fibroid volume reduction were 42.8% and 48.8%, respectively (mean follow-up, 10.2 months). One infectious complication that necessitated hysterectomy occurred. CONCLUSION: Uterine artery embolization for the treatment of uterine fibroids is a minimally invasive technique with low complication rates and very good clinical efficacy.

Adult↗
PubMed1998

Suppression of caveolin expression induces androgen sensitivity in metastatic androgen-insensitive mouse prostate cancer cells.

Although prostate cancer cells are often initially sensitive to androgen ablation, they eventually lose this response and continue to survive, grow and spread in the absence of androgenic steroids. The mechanism(s) that underlie resistance to androgen ablation therapy remain mostly unknown. We have demonstrated that elevated caveolin protein levels are associated with human prostate cancer progression in pathological specimens. Here we show that suppression of caveolin expression by a stably transfected antisense caveolin-1 cDNA vector converted androgen-insensitive metastatic mouse prostate cancer cells to an androgen-sensitive phenotype. Orthotopically grown tumors and low-density cell cultures derived from antisense caveolin clones had increased apoptosis in the absence of androgenic steroids, whereas similarly grown tumors and cells from vector (control) clones and parental cells were not sensitive to androgens. Studies using a representative antisense caveolin clone showed that selection for androgen resistance in vivo correlated with increased caveolin levels, and that adenovirus-mediated caveolin expression blocked androgen sensitivity. Our results identify a new candidate gene for hormone-resistant prostate cancer in man and indicate that androgen insensitivity can be an inherent property of metastatic prostate cancer.

Androgens↗
PubMed1990

Computed tomography scans and negative symptoms in schizophrenia: chronic schizophrenics with negative symptoms and nonenlarged lateral ventricles.

Computed tomography scans of 31 chronic schizophrenics with negative symptoms and 31 age-matched normal volunteers were assessed for ventricular size, cortical atrophies, third ventricle diameter, and cerebellar atrophies. No significant differences were found in the size of the lateral ventricles or third ventricles between the chronic schizophrenics and the controls. The frontal horns in patients did show a tendency toward increased size compared with controls. Sulci width showed significant differences between patients and controls. The clinical variables, except for the memory test, did not correlate with any brain morphology. A meta-analysis was performed on 17 studies that used the planimetric method in order to evaluate the relationships between the size of the lateral ventricles in patients and their respective controls. We found significant differences between the group of studies using normal controls and the group using medical controls.

Adult↗
PubMed1985

Nutritional improvement of poor urban preschool children. A 1983-1977 comparison.

The nutritional status of preschool children from 1,219 families living in an urban poverty area was surveyed in 1983 and these results were compared with findings from a similar survey of the same community done in 1977. A second comparison was made of children whose families participated in a commodity supplementary food program and those whose families did not participate. Results of the 1983 survey indicated improvements in median serum levels of vitamins A and C, hemoglobin, and red blood cell volume. Nevertheless, 9% to 18% of the children had low or deficient levels of vitamins A, C, B1, and B2, hemoglobin, serum iron, and transferrin saturation. Also a greater number of the preschoolers were categorized as thin. Annual incomes for families had significantly decreased from 1977 when the median value for food recipients was +3,078 to a median of +1,848 in 1983. Considering the decrease in other resources, federal food assistance programs seem to be the only identifiable factor contributing to the improvement in nutritional status over 1977.

Avitaminosis↗
PubMedDate not supplied

CT findings after uterine artery embolization.

Asymptomatic uterine leiomyoma can be detected on routine computed tomography (CT) of the pelvis. Leiomyomas have been described as low attenuation masses that can disrupt the smooth contour of a normal uterus. Four women underwent uterine artery embolization for the treatment of uterine leiomyoma. CT findings include initial retention of contrast in fibroids the day of the procedure and central necrosis of the fibroid with subsequent cavitation as early as 1 month postprocedure.

Adult↗