Biomedical subjects

Robert Grant

Publications and source records attributed to Robert Grant.

5 recordsLinked to original sources

PubMed2007

Frequent methamphetamine use is associated with primary non-nucleoside reverse transcriptase inhibitor resistance.

We determined whether methamphetamine use is associated with the increased prevalence of primary HIV drug resistance among a cohort of men who have sex with men recently infected with HIV. In multivariate analysis, we found that frequent methamphetamine use was strongly associated with primary non-nucleoside reverse transcriptase inhibitor resistance, but not with protease inhibitor or nucleoside reverse transcriptase inhibitor resistance. We postulate that this association may be caused by methamphetamine-associated treatment interruptions among source partners.

Adult↗

PubMed2006

HIV-1-specific CD4+ T cell responses in chronically HIV-1 infected blippers on antiretroviral therapy in relation to viral replication following treatment interruption.

The impact of transient viral load blips on anti-HIV-1 immune responses and on HIV-1 rebound following treatment interruption (TI) is not known. Clinical and immunological parameters were measured during 40 weeks of antiretroviral therapy (ART) and following TI in an observational cohort of 16 chronically HIV-1-infected subjects with or without observed viral load blips during ART. During therapy, blips in seven subjects were associated with higher anti-HIV-1 (p24) CD4+ T cell lymphoproliferative responses (p = 0.04), without a significant difference in T cell activation or total anti-HIV-1 CD8+ T cell interferon-gamma (IFN-gamma) responses when compared to nine matched non-blippers. Therapy interruption resulted in a significantly higher viral rebound in blippers by 8 week despite retention of higher lymphoproliferative p24 responses (p = 0.01) and a rise in CD3+ T cell activation (p = 0.04) and anti-HIV-1 CD8+ T cell responses in blippers by week 4 when compared to non-blippers. Past week 4 of interruption, therapy re-initiation criteria were also met by a higher frequency in blippers by week 14 (p < 0.04) with no difference between groups by week 24. These data support that blippers have higher anti-HIV lymphoproliferative responses while on ART but experience equal to higher viral rebound as compared to matched non-blippers upon TI.

Anti-HIV Agents↗

PubMed2004

Use of topical sRAGE in diabetic wounds increases neovascularization and granulation tissue formation.

Advanced glycation end products (AGEs) accumulate in diabetic wounds as a result of the glycosylation of various proteins. Interaction of AGEs with the receptor for AGEs (RAGE) results in an exaggerated inflammatory response and compromised collagen production. These changes lead to impaired wound healing. A soluble form of RAGE (sRAGE) has been shown to bind AGEs and thereby blunt their pathogenetic effects. Using genetically diabetic C57BLks-db/db mice, the authors applied sRAGE topically to standardized full-thickness wounds to improve diabetic wound healing. They measured various parameters of wound healing such as neovascularization, reepithelialization, collagen formation, and granulation tissue area. Their results showed a statistically significant increase in granulation tissue area and microvascular density in the sRAGE group compared with untreated wounds. There was a trend toward a smaller epithelial gap in the sRAGE-treated group that did not reach statistical significance. The authors conclude that sRAGE may be a powerful treatment of accelerating diabetic wound healing.

Administration, Topical↗

PubMed2003

Substance abuse in a Canadian population of Assertive Community Treatment (ACT) clients: implications for service planning and delivery.

This brief paper reports on a study that used diagnosis, client self-reports, and clinician ratings to estimate the prevalence of drug, alcohol, and tobacco abuse among a random sample of 174 clients of 4 Assertive Community Treatment (ACT) teams in southeastern Ontario, Canada. Drug and alcohol abuse rates were lower that those reported in the literature, while high rates for tobacco use were consistent with published reports. ACT service delivery is guided by formal standards that assume high rates of substance abuse. It is argued that local population profiles should be monitored and considered in the development of ACT intervention practices.

Adult↗

PubMed2002

Imaging response to chemotherapy with RMP-7 and carboplatin in malignant glioma: size matters but speed does not.

INTRODUCTION: In recurrent malignant glioma, early imaging response to two courses of chemotherapy is generally considered to be predictive of good survival. We studied the relationships between initial tumour volume and speed of imaging response to chemotherapy in malignant glioma. METHODS: In 43 chemotherapy naïve patients, 26 glioblastoma multiforme (GBM) + 17 anaplastic astrocytoma (AA), median age 45 years, MRI responses to intravenous cereport and carboplatin were assessed at baseline, then at 2 monthly intervals. Patients were classified as fast responders if they had reached a partial response (PR) after two courses, and slow responders if PR was achieved after three or more courses of chemotherapy. RESULTS: PR occurred in four patients with GBM (15%) and nine patients with AA (53%). Likelihood of response was related to initial tumour enhancing volume in GBM but not in AA. PR occurred in four of five GBM patients (80%) with initial volume < 15,000 mm3 and none of the 21 cases with an initial volume > 15,000 mm3. In patients achieving a PR, there was no association between speed or duration of response and eventual survival. Fast responders with AA were significantly older than slow responders (p = 0.033). CONCLUSIONS: Initial enhancing volume of GBMs may be an important predictor of imaging response. This has implications where response rates of phase II studies are reported and in stratification for phase III trials. Further work is necessary to confirm these findings with other types of chemotherapy and examine the relationship between proliferation markers and speed of response.

Adult↗