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Biomedical subjects

Richard Groves

Publications and source records attributed to Richard Groves.

9 recordsLinked to original sources
PubMed2006

Tumor necrosis factor-alpha- and IL-4-independent development of Langerhans cell-like dendritic cells from M-CSF-conditioned precursors.

GM-CSF and transforming growth factor beta (TGFbeta ) are required for the generation of Langerhans cells (LC), members of the dendritic cell (DC) family. Tumor necrosis factor alpha (TNFalpha) and IL-4 can enhance LC differentiation from human monocytes or CD34(+) progenitors. Here, we show that M-CSF-cultured DC precursors derived from CD34(+) progenitors resemble dermal CD14(+) cells and readily convert to LC-like DC in GM-CSF/TGFbeta. The cells express Langerin, CD1a, and CCR6, migrate in response to CCR6 ligand CCL20, and contain Birbeck granules. TNFalpha and IL-4, added separately or together, have an inhibitory effect on LC differentiation. Cells differentiated in the presence of IL-4 and TNFalpha express low levels of CCR7. This suggests that M-CSF-conditioned DC precursors retain the capacity to efficiently undergo a differentiation program, giving rise to LC-like DC solely through the effect of GM-CSF and TGFbeta.

Antigens, CD↗
PubMed2004

Photodynamic therapy using topical methyl aminolevulinate vs surgery for nodular basal cell carcinoma: results of a multicenter randomized prospective trial.

BACKGROUND: Photodynamic therapy (PDT) is increasingly used as a noninvasive treatment for nodular basal cell carcinoma (BCC), without a sound evidence base. OBJECTIVE: To compare topical PDT, with the use of the sensitizer methyl aminolevulinate, and standard excision surgery in nodular BCC. DESIGN: Prospective, randomized study. SETTING: University dermatology departments. PATIENTS: A total of 101 adults with previously untreated nodular BCC. INTERVENTIONS: Patients received methyl aminolevulinate PDT (n = 52) or surgery (n = 49). The PDT was given twice, 7 days apart, with methyl aminolevulinate cream (160 mg/g) and 75 J/cm(2) red light (570-670 nm). Thirteen patients with a noncomplete response to PDT at 3 months (24% lesions) were retreated. OUTCOME MEASURES: Primary end point was clinically assessed lesion clearance at 3 months after treatment. Secondary end points were sustained response rate at 12 months and cosmetic outcome at 3 and 12 months. Cosmesis and lesion recurrence were further assessed at 24 months. RESULTS: Data from 97 patients (105 lesions) were included in the 3-month per-protocol analysis. Complete response rates did not differ significantly between groups (51/52 [98%] lesions with surgery vs 48/53 [91%] lesions with methyl aminolevulinate PDT; difference [95% confidence interval], 4.8% (-3.4% to 13.0%]; P =.25). At 12 months, tumor-free rates were 50 (96%) of 52 lesions with surgery vs 44 (83%) of 53 with methyl aminolevulinate PDT (P =.15). More patients treated with methyl aminolevulinate PDT than surgery had an excellent or good cosmetic outcome at all time points (significant at 12 and 24 months on patient assessment, P<.05, and at 3, 12, and 24 months on investigator evaluation, P<.001). At 24 months, 5 lesions that had initially cleared with methyl aminolevulinate PDT had recurred, compared with 1 after surgery. CONCLUSIONS: Methyl aminolevulinate PDT is an effective treatment for nodular BCC, and while there is a trend for higher recurrence with this modality, it conveys the advantage over surgery of better cosmesis.

Administration, Topical↗
PubMed2004

Expression of activated MEK1 in differentiating epidermal cells is sufficient to generate hyperproliferative and inflammatory skin lesions.

Epidermal activation of Erk MAPK is observed in human psoriatic lesions and in a mouse model of psoriasis in which beta1 integrins are expressed in the suprabasal epidermal layers. Constitutive activation of the upstream kinase MEK1 causes hyperproliferation and perturbed differentiation of human keratinocytes in culture. It is not known, however, whether Erk activation in differentiating keratinocytes is sufficient to trigger hyperproliferation of basal keratinocytes and a skin inflammatory infiltrate. To investigate this, we expressed constitutively active MEK1 in the suprabasal epidermal layers of transgenic mice. Proliferation in the epidermal basal layer was stimulated and epidermal terminal differentiation was perturbed. Some older mice also developed papillomas. There was a large increase in T lymphocytes, dendritic cells, and neutrophils in the skin. The effects of suprabasal MEK1 on basal keratinocytes and leukocytes, cells that were transgene negative, suggested that MEK1 activity might stimulate cytokine release. Transgenic keratinocytes expressed elevated IL-1alpha and crossing the mice with mice overexpressing the IL-1 receptor in the epidermal basal layer led to exacerbated hyperproliferation and inflammation. These data suggest that activation of MEK1 downstream of beta1 integrins plays an important role in epidermal hyperproliferation and skin inflammation.

Animals↗
PubMed2003

NKT cell subsets in infection and inflammation.

We recently identified two stably expressed cell surface markers, IL-18R and ST2L, which are selectively expressed on T1/NK1 and T2/NK2 cells, respectively. Here we use these molecules in direct ex vivo analysis of PBMCs from patients with AIDS, psoriasis (PS) atherosclerosis and to show the importance of these markers as determinants of the functional dichotomy of lymphocyte subsets, in particular NKT. In a cohort of 22 HIV patients made up of a mixture of long term non-progressors, seroconvertors, progressors and asymptomatics, we found a clear NKT1 to NKT2 shift (P=0.001) in the HIV-infected individuals. We also show a predominance of NKT2 cells over NKT1 cells in the PBMCs of patients with mild to moderate PS (N=13, P=0.005) but not in atopic dermatitis or healthy controls. However, in patients (N=6) requiring surgery for aneurysm, a predominance of Type 1 (IL-18R(+)) NKT lymphocytes over NKT2 was detected among infiltrating lymphocytes isolated from atherosclerotic plaques. Our data therefore demonstrate that ST2L and IL-18R could serve as important determinants of the immune status of human diseases.

Acquired Immunodeficiency Syndrome↗