Biomedical subjects

L Davila

Publications and source records attributed to L Davila.

6 recordsLinked to original sources

PubMed2007

Influence of 4- and 6-color flow cytometers and acquisition/analysis softwares on the determination of lymphocyte subsets in HIV infection.

BACKGROUND AND OBJECTIVES: Lymphocyte immunophenotyping provides valuable information for the diagnosis and monitoring of patients with cellular immunodeficiencies, such as HIV/AIDS. In this study, we have assessed the influence of 4-color and 6-color flow cytometers, and respective analytical softwares on the enumeration of lymphocytes in HIV infected individuals. METHODS: The expression of various cell surface markers on lymphocytes was measured from the EDTA blood of 66 HIV infected patients on the FACSCalibur (4-color) and FACSCanto (6-color) flow cytometers. Percentage of lymphocytes expressing a particular cell surface marker was analyzed on FACSCalibur using the Cell Quest Pro software (v 5.2), while the analysis on FACSCanto was done using FACSCanto (v 1.0.3) and FACSDiva (v 4.1) softwares respectively. RESULTS: The data shows significantly higher mean CD3 T-cell counts on FACSCalibur, Cell Quest Pro (1,864 +/- 1,044 cells/microl) as compared to FACSCanto (1,840 +/- 1,040 cells/microl) (P < 0.05). The CD4 T-cell counts were also higher on FACSCalibur, Cell Quest Pro (885 +/- 770 cells/microl), and FACSDiva (892 +/- 773 cells/microl) versus FACSCanto (867 +/- 767 cells/microl) (P < 0.05). FACSCalibur, Cell Quest Pro, and FACSDiva showed similar values except for CD8 T-lymphocytes where FACSDiva had significantly lower values (P < 0.05). The B-cell counts were unaffected when either of the instruments or softwares were used, while the natural killer (NK) cells (CD16 + 56 positive cells) showed similar trend like CD3 and CD4 counts with significant differences in the mean cell counts between FACSCalibur, Cell Quest Pro (240 +/- 165 cells/microl), and FACSDiva (238 +/- 163 cells/microl) versus FACSCanto with higher NK cell counts (260 +/- 176 cells/microl). CONCLUSIONS: The enumeration of lymphocyte subsets was comparable between FACSCalibur, Cell Quest Pro, and FACSDiva, based analysis and it was significantly different than FACSCanto software based analysis. Our observations suggest that FACSDiva software should be preferred over the FACSCanto software for immunophenotyping on FACSCanto flow cytometer and the laboratories should report the instrument and software used for the specimen analysis while reporting immunophenotyping results.

Antigens, Surface↗

PubMed1993

Experimental carcinomatous plexopathy.

To understand the pathophysiology of carcinomatous plexopathy better, we studied nerve lesions induced by an experimental thyroid carcinoma implanted over the brachial plexus in 30 Fisher rats. We performed a morphological study including light and electron microscopic examination and teased fibre preparations of brachial plexuses from implanted and control animals. The control side was normal in all. A large tumour always grew within 2 months in all implanted animals and a third of the rats eventually developed weakness of the corresponding anterior limb extremity. On gross examination the tumour always surrounded the brachial plexus, which showed a variety of microscopic abnormalities, ranging from isolated endoneurial oedema to total degeneration of nerve fibres in 41% of the implanted rats. The most frequent lesions consisted of segmental demyelination associated with endoneurial oedema at the site of compression. Some axons degenerated distally and regeneration by sprouting of the proximal stump was noted 80 days after implantation. All subpopulations of nerve fibres were equally affected. Invasion of the intrafascicular area by the tumour was an uncommon finding, in comparison with the constant entrapment of the branches of the plexus by the tumour. This invasion by the tumour induced demyelination of nerve fibres at the site of compression, and sometimes at a distance from the tumour. Regeneration did not occur when the tumour had invaded the intrafascicular area.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1992

Treatment of malignant gliomas with surgery, intraarterial chemotherapy with ACNU and radiation therapy.

Forty patients with malignant supratentorial gliomas received iterative intraarterial (IA) infusions of ACNU, 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea at a dose of 150 mg repeated every 6 weeks. Group A consisted of eighteen patients previously treated with surgery, radiation therapy (RT) and sometimes chemotherapy, who received IA ACNU at tumor recurrence. Group B consisted of twenty two patients who received IA ACNU in the postoperative pre-RT period. In group A, 8/18 patients (44%) had an objective response, including 6/12 anaplastic astrocytomas (AA) and 2/6 glioblastoma multiforme (GBM), while 10/18 patients (56%) did not respond. Median survival time was 6 months for GBM and 12 months for AA. In group B, 6/22 patients (27%) had an objective response (4/18 GBM and 2/4 AA) and 16/22 patients (73%) did not respond. Nine patients had such an extensive tumor after one or two courses of IA ACNU that RT was cancelled. Median survival time was 8 months for GBM and 8 months for AA. Three patients (8%) had ophthalmologic toxicity on the infused side. There was no case of leukoencephalopathy.

Adult↗

PubMed1991

[Autoimmunity and paraneoplastic neurologic syndromes].

Paraneoplastic syndromes affecting the nervous system are rare and their diagnosis is often difficult when the original cancer is unknown. Recently, high levels of antineuronal antibodies (AB) have been found in serum and CSF of some patients with paraneoplastic syndromes. The anti-Yo AB recognizes 2 proteins of 34 and 62 kd in the cytoplasm of Purkinje cells and in malignant cells of patients suffering from paraneoplastic cerebellar degeneration associated with ovarian and breast cancer. The anti-Hu AB recognizes a 37-40 kd protein in nuclei of neurons and in tumor cells of patients suffering from subacute sensory neuronopathy and encephalomyelitis associated with small cell lung cancer. Other antineuronal AB have been more rarely identified. The presence of high titer of one of these AB in a patient with suspected paraneoplastic syndrome is of great practical interest since it confirms the neurological diagnosis and strongly suggests the location of the primary tumor when the malignancy is unknown. The pathogenetic role of the antineuronal AB is unknown but it is likely that some paraneoplastic syndromes affecting the nervous system are due to an immune reaction against antigens shared by the tumor and the nervous system. To date, no efficient treatment has been found.

Autoantibodies↗

PubMed1990

Treatment of malignant gliomas with surgery, intra-arterial infusions of 1-(2-hydroxyethyl)chloroethylnitrosourea, and radiation therapy: a phase II study.

Forty patients with malignant supratentorial gliomas were treated with surgery, intra-arterial infusions of 1-(2-hydroxyethyl)chloroethylnitrosourea, and radiation therapy. The median duration of survival was 12 months; it differed according to the histological subtype (over 30 months for patients with anaplastic astrocytomas or anaplastic oligodendroglioma and 10.5 months for glioblastoma; P = 0.0025). Serious complications of monocular blindness and leukoencephalopathy were observed in four patients (10%).

Adolescent↗

PubMed1990

[Metastasis to the pituitary stalk in a case of breast cancer].

A 64-year old woman with breast cancer developed diabetes insipidus. CT scan showed thickening and contrast enhancement of the pituitary stalk highly suggestive of metastasis. The patient was successfully treated with desmopressin followed by external radiation therapy.

Breast Neoplasms↗