PubMed Health⌕ Search

Biomedical subjects

David Simpson

Publications and source records attributed to David Simpson.

At least 55 records · Page 3Linked to original sources
PubMed2004

A randomized controlled trial of 5% lidocaine gel for HIV-associated distal symmetric polyneuropathy.

OBJECTIVE: To investigate the analgesic efficacy and safety of 5% lidocaine gel in painful HIV-associated distal sensory polyneuropathy (DSP). BACKGROUND: Painful DSP, the most common neurologic complication in HIV infection, is difficult to treat. Lidocaine 5% gel was effective in alleviating neuropathic pain in an open-label study of HIV DSP. METHODS: In a double-blind, placebo-controlled, crossover, multi-center study, 64 subjects were randomized to receive 5% lidocaine or vehicle gel for 2 weeks (phase A). A washout period of 2 weeks was followed by a crossover to the alternate agent for another 2 weeks (phase B). The primary outcome was difference in average pain scores (Gracely pain scale) between the 2 groups during the second week of each treatment period. Secondary outcomes included differential effect of the first treatment, difference in global pain relief, and pain response by neurotoxin exposure. RESULTS: The baseline pain scores of the 2 groups were similar. The average pain scores during the second week of each phase of the lidocaine gel group did not differ from those of the placebo group (phase A: lidocaine 1.09, placebo 1.15; phase B: lidocaine 1.16, placebo 1.10). There also was no difference noted in secondary outcomes. The pain responses of lidocaine gel-treated subjects with current exposure to neurotoxic antiretrovirals (1.18) did not differ compared with those without (1.10) (P = 0.358). There were no significant adverse effects. CONCLUSION: Lidocaine 5% gel is a safe but ineffective agent in the treatment of pain in HIV-associated DSP.

Anesthetics, Local↗
PubMed2004

Separate membrane targeting and anchoring domains function in the localization of the S. cerevisiae Cdc24p guanine nucleotide exchange factor.

The Saccharomyces cerevisiae Cdc24p guanine nucleotide exchange factor (GEF) activates the Cdc42p GTPase to a GTP-bound state. Cdc42p and Cdc24p co-localize at polarized growth sites during the cell cycle; and analysis of Cdc24p carboxyl-terminal truncation and site-specific mutations identified a 56-amino-acid domain as being necessary and sufficient for localization to these sites. This domain, however, was unable to anchor Cdc24p at these sites. Anchoring was restored by fusing the targeting domain to either the Cdc24p carboxyl-terminal PC domain that interacts with the Bem1p scaffold protein or the Cdc42p KKSKKCTIL membrane-anchoring domain. Mutant analysis and protein solubilization data indicated that anchoring required Bem1p, the Rsr1p/Bud1p GTPase, and the potential transmembrane protein YGR221Cp/Tos2p. These data are consistent with Cdc24p localization being a function of both membrane-specific targeting and subsequent anchoring within a multi-protein complex. Given the highly conserved roles of GEFs in Cdc42p signaling pathways, it is likely that similar targeting and anchoring mechanisms exist for Rho GEFs in other eukaryotes.

Adaptor Proteins, Signal Transducing↗
PubMed2004

HIV-associated distal sensory polyneuropathy in the era of highly active antiretroviral therapy: the Manhattan HIV Brain Bank.

OBJECTIVES: To examine distal sensory polyneuropathy (DSP) in a highly active antiretroviral therapy era, human immunodeficiency virus (HIV)-infected cohort, to determine whether clinical manifestations are affected by demographic or other clinical variables. PATIENTS: One hundred eighty-seven patients with HIV infection enrolled in the Manhattan HIV Brain Bank underwent baseline neurologic evaluations between January 29, 1999, and June 17, 2002. Distal sensory polyneuropathy was diagnosed if patients displayed abnormalities in 2 or more of the following: ankle reflexes or vibratory or pinprick perception. Patients were classified as symptomatic if they described pain, paresthesia, or numbness. Nonneurologic information was obtained by interview, laboratory testing, and medical chart review. Psychiatric and substance use disorders were elucidated by semistructured interview. In 36 patients, morphometric analysis was performed on autopsy-derived sural nerves. RESULTS: Of 187 patients, 99 (53%) had DSP. Patients with neuropathy were older than those without (mean +/- SD age, 45.3 +/- 0.7 vs 41.2 +/- 0.8 years, P <.001), and DSP was significantly more common in men (58% [83/99]) than in women (37% [16/99]) (P =.02). The presence of neuropathy was not correlated with plasma viral load, decreased CD4 cell counts, or neurotoxic antiretroviral therapy. Twenty-six of 99 patients with DSP were asymptomatic. Asymptomatic neuropathy was correlated with histories of opiate and sedative abuse and dependence. Symptomatic DSP correlated with ethanol and hallucinogen syndromes, but not neurotoxic therapy. Sural nerve morphometric findings did not distinguish between patients with substance use syndromes and those without. CONCLUSIONS: In contrast to populations before the era of highly active antiretroviral therapy, DSP in the Manhattan HIV Brain Bank cohort is not associated with increased viral load or decreased CD4 cell counts in this cross-sectional analysis. Symptoms in DSP are associated with substance use disorders, but no difference in morphologic structure is seen in nerves of patients with HIV infection with and without substance use histories. Previously reported virologic and immunologic underpinnings of DSP may be affected by highly active antiretroviral therapy. Furthermore, symptoms of DSP in substance users may be altered by central mechanisms of increased or decreased tolerance to sensory disturbance.

Adult↗
PubMed2004

Controlling neuropathic pain in HIV.

Neuropathic pain is associated with numerous systemic illnesses, including HIV infection. The diagnosis and management of peripheral neuropathy presents diagnostic and therapeutic challenges. Among various forms of HIV-associated peripheral neuropathies, distal symmetrical polyneuropathy (DSP) is the most common. DSP may be caused or exacerbated by neurotoxic antiretrovirals, particularly the dideoxynucleoside analogues (d-drugs). Selection of appropriate pharmacologic intervention for peripheral neuropathy should be based on efficacy, safety, ease of administration, and cost. We review treatment options for painful HIV neuropathy, including experimental agents studied in recent and ongoing clinical trials.

Analgesics↗
PubMed2004

Controlling Neuropathic Pain in HIV.

Neuropathic pain is associated with numerous systemic illnesses, including HIV infection. The diagnosis and management of peripheral neuropathy presents diagnostic and therapeutic challenges. Among various forms of HIV-associated peripheral neuropathies, distal symmetrical polyneuropathy (DSP) is the most common. DSP may be caused or exacerbated by neurotoxic antiretrovirals, particularly the dideoxynucleoside analogues (d-drugs). Selection of appropriate pharmacologic intervention for peripheral neuropathy should be based on efficacy, safety, ease of administration, and cost. We review treatment options for painful HIV neuropathy, including experimental agents studied in recent and ongoing clinical trials.

Journal Article↗
PubMed2004

Neuromuscular complications in HIV.

HIV affects many organs of the body, including the nervous system. As a result, a series of neurologic complications have created challenges for scientists and clinicians alike. Among these, HIV-associated neuropathy and myopathy may occur at all stages of the disease process. Of the neuropathies, distal symmetrical polyneuropathy is the most common form. The pathogenesis of primary HIV neuropathy is unknown. Other types of neuropathy seen in HIV-infected subjects include toxic neuropathy, inflammatory demyelinating polyneuropathy, progressive polyradiculopathy, and mononeuritis multiplex. In this review, we present the clinical manifestations, pathogenesis, diagnosis, and management of different types of neuropathy in HIV infection. Myopathy, another complication of HIV, is not associated with any particular stage of immunosuppression. Symptoms include symmetrical weakness of the proximal muscles in the extremities. Serum creatine kinase levels are often moderately elevated. Electromyography and muscle biopsy are helpful tests for diagnosis. Treatment of HIV myopathy includes corticosteroids, nonsteroidal anti-inflammatory agents, and intravenous immunoglobulin.

HIV Infections↗
PubMed2004

An evaluation of the donor experience in the canadian multicenter randomized trial of bone marrow versus peripheral blood allografting.

We compared the donation of bone marrow (BM) versus recombinant human granulocyte colony-stimulating factor-mobilized peripheral blood progenitor cells (PBPC) in HLA-matched sibling donors. Donors randomized to donate BM or PBPC completed questionnaires (Profile of Mood States [POMS] and Short-Form 36 Health Survey) assessing peridonation health-related quality of life (QoL), donation experience, and acceptability of donation before and 1 week and 4 weeks after donation. Between January 1996 and March 1999, 184 patients and their donors were randomized. Predonation and postdonation data were available on 52 (56%) and 35 (38%) of the BM and PBPC donors, respectively. The median donor age was 45 years, and 44% were female. The median time (range) to return to full activity for the BM and PBPC donors was 4 days (1-21 days) and 2 days (0-21 days), respectively (P = .01). One week after donation, BM donors reported more fatigue and less energy than the PBPC donors. BM donors' POMS total mood disturbance scores were worse 1 week after versus before donation, whereas the PBPC donors' scores did not change. POMS subscores indicated more fatigue and less energy in the BM versus PBPC donors. Anxiety improved in both groups, but more in PBPC donors. Four weeks after donation, the Short-Form 36 Health Survey indicated persistent moderate negative effects on QoL with BM donation versus small effects with PBPC donation. BM donation was associated with more physical morbidity and negative effects on QoL up to 1 month after donation than was PBPC donation. Despite this, most donors would donate again. Further work is needed to decrease donor anxiety and symptoms. If both BM and PBPC donation are feasible, then the graft source should be dictated by the predicted patient outcome as determined from the results of randomized trials.

Affect↗
PubMed2004

HIV neuromuscular disease and mitochondrial function.

The pathogenesis of neuromuscular syndromes in HIV-infected patients is multifactorial. Of recent concern is the mitochondrial-mediated neuromuscular pathology in HIV and its treatment. We present currently available evidence supporting the role of mitochondrial pathology in the peripheral nerve and muscle disorders due to HIV infection and antiretroviral (ARV) therapy. Three neuromuscular syndromes are discussed: distal symmetric polyneuropathy (DSP), myopathy, and HIV-associated neuromuscular weakness syndrome (HANWS). Myopathy has the most in-vivo data relating to HIV-related mitochondrial pathology, while DSP and HANWS have growing evidence of mitochondrial pathology, particularly in the context of ARV use. It is likely that these neuromuscular disorders result from a combination of mitochondrial and immunological mechanisms due to HIV and ARV therapy.

Journal Article↗