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Biomedical subjects

W Townsend

Publications and source records attributed to W Townsend.

8 recordsLinked to original sources
PubMed1999

Tumor metastasis biopsy as a surrogate marker of response to melanoma immunotherapy.

In patients undergoing immunotherapy for metastatic melanoma, the clinical response in immunotherapeutic trials may be partial or difficult to detect. Tumor metastasis biopsy allows direct characterisation of an anti-tumor immunological response. During a phase I/II trial of granulocyte macrophage colony stimulating factor (GM-CSF) transduced autologous melanoma immunotherapy, the cellular response was examined by immunohistochemical analysis in a limited number of tumor biopsies taken from patients who either responded or progressed. Clinical response was associated with tumor infiltration by CD4+ and CD8+ T-cells, macrophages and differentiated dendritic cells (DC), and expression of HLA-DR by the tumor cells. This tumor infiltration was associated with increased melanoma-specific peripheral blood precursor cytotoxic T-lymphocyte (pCTL) and the ability to obtain tumor-infiltrating lymphocytes in vitro. In contrast, progression or a lack of clinical response was associated with a lack of T-cell and DC infiltration into the tumor tissue in all such biopsies. Macrophages and eosinophils infiltrated these tumors, while T-cells and DC were present at some distance from the tumor. These preliminary data strongly suggest that the location and extent of T-cell and DC infiltration, as well as the expression of HLA-DR by tumor cells are associated with a clinical response in this form of melanoma immunotherapy.

Adult↗
PubMed1997

Nuclear localization of RelB is associated with effective antigen-presenting cell function.

Dendritic cells (DC) are potent APCs that enter resting tissues as precursors and, after Ag exposure, differentiate and migrate to draining lymph nodes. The phenotype of RelB knockout mice implicates this member of the NF kappa B/Rel family in DC differentiation. To further elucidate the role of RelB in DC differentiation, mRNA, intracellular protein expression, and DNA binding activity of RelB were examined in immature and differentiated human DC, as well as other PB mononuclear cell populations. RelB protein and mRNA were detected constitutively in lymphocytes and in activated monocytes, differentiated DC, and monocyte-derived DC. Immunohistochemical staining demonstrated RelB within the differentiated lymph node interdigitating DC and follicular DC, but not undifferentiated DC in normal skin. Active nuclear RelB was detected by supershift assay only in differentiated DC derived from either PB precursors or monocytes and in activated B cells. These RelB+ APC were potent stimulators of the MLR. The data indicate that RelB expression is regulated both transcriptionally and post-translationally in myeloid cells. Within the nucleus, RelB may specifically transactivate genes that are critical for APC function.

Adult↗
PubMed1995

Ocular findings in the Hermansky-Pudlak syndrome.

BACKGROUND: The Hermansky-Pudlak syndrome (HPS) is defined by the autosomal recessively inherited triad of tyrosinase-positive oculocutaneous albinism, bleeding diathesis and accumulation of ceroid in tissues. Late complications include: interstitial pulmonary fibrosis; inflammatory bowel disease; and renal failure. PATIENTS AND METHODS: We undertook a non-concurrent prospective study of 55 Puerto Rican patients with HPS (age range 1 to 54 yrs; mean = 19.7 yrs). These patients had a comprehensive ocular examination and a systemic evaluation for HPS. RESULTS: Visual acuities ranged from 20/50 to 5/200. All patients had nystagmus. Forty-three patients had strabismus; esotropia was found in 24 patients; exotropia in 18 patients; and one patient had hypertropia. Posterior embryotoxon occurred in 15 patients and Axenfeld anomaly in 4 patients. Iris pigmentation varied from minimal to almost completely normal. Three patients had cataract formation. The retina was typically albinotic with macular hypoplasia. All patients had cutaneous albinism, bleeding diathesis and various systemic manifestations as part of HPS. CONCLUSION: Ocular findings in HPS include reduced visual acuity; congenital nystagmus, strabismus and cataract. Diagnosis of the syndrome ought to be made preoperatively to help minimize the potential complications associated with bleeding diathesis at the time of extraocular muscle and intraocular surgery in patients with HPS.

Adolescent↗
PubMed1991

Prevalence of the microbiologic flora in contact lens wearers at the Puerto Rico Medical Center.

The prevalence of microbioogic flora was determined in a convenience sample of contact lens wearers at the Puerto Rico Medical Center, ophthalmology clinics obtaining cultures from the conjunctival fornices. Gram positive bacterial prevalence was 100% in the control group, as well as in rigid gas permeable lens wearers. In the soft contact lens group, gram positive bacterial prevalence was 94.7%. On the other hand prevalence of Gram negative bacteria is null in the soft contact lens wearer population, being only 2.5% in control group, and 45.5% for Rigid Gas Permeable wearers. These contact lens wearers were using different disinfection systems.

Bacteria↗