Biomedical subjects

James R Couch

Publications and source records attributed to James R Couch.

6 recordsLinked to original sources

PubMed2005

Risk of lung cancer and leukemia from exposure to ionizing radiation and potential confounders among workers at the Portsmouth Naval Shipyard.

Significantly elevated lung cancer deaths and statistically significantly positive linear trends between leukemia mortality and radiation exposure were reported in a previous analysis of Portsmouth Naval Shipyard workers. The purpose of this study was to conduct a modeling-based analysis that incorporates previously unanalyzed confounders in exploring the exposure-response relationship between cumulative external ionizing radiation exposure and mortality from these cancers among radiation-monitored workers in this cohort. The main analyses were carried out with Poisson regression fitted with maximum likelihood in linear excess relative risk models. Sensitivity analyses varying model components and using other regression models were conducted. The positive association between lung cancer risk and ionizing radiation observed previously was no longer present after adjusting for socioeconomic status (smoking surrogate) and welding fume and asbestos exposures. Excesses of leukemia were found to be positively, though not significantly, associated with external ionizing radiation, with or without including potential confounders. The estimated excess relative risk was 10.88% (95% CI -0.90%, 38.77%) per 10 mSv of radiation exposure, which was within the ranges of risk estimates in previous epidemiological studies (-4.1 to 19.0%). These results are limited by many factors and are subject to uncertainties of the exposure and confounder estimates.

Adult↗

PubMed2004

Topiramate for migraine prevention: a randomized controlled trial.

CONTEXT: Small open-label and controlled trials suggest that the antiepileptic drug topiramate is effective for migraine prevention. OBJECTIVE: To assess the efficacy and safety of topiramate for migraine prevention in a large controlled trial. DESIGN, SETTING, AND PATIENTS: A 26-week, randomized, double-blind, placebo-controlled study was conducted during outpatient treatment at 52 North American clinical centers. Patients were aged 12 to 65 years and had a 6-month history of migraine (International Headache Society criteria) and 3 to 12 migraines a month but no more than 15 headache days a month during a 28-day prospective baseline phase. INTERVENTIONS: After a washout period, patients meeting entry criteria were randomized to topiramate (50, 100, or 200 mg/d) or placebo. Topiramate was titrated by 25 mg/wk for 8 weeks to the assigned or maximum tolerated dose, whichever was less. Patients continued receiving that dose for 18 weeks. MAIN OUTCOME MEASURES: The primary efficacy measure was change from baseline in mean monthly migraine frequency. Secondary efficacy measures included responder rate (proportion of patients with > or =50% reduction in monthly migraine frequency), reductions in mean number of monthly migraine days, severity, duration, and days a month requiring rescue medication, and adverse events. The month of onset of preventive treatment action was assessed. RESULTS: Of 483 patients randomized, 468 provided at least 1 postbaseline efficacy assessment and comprised the intent-to-treat population. Mean monthly migraine frequency decreased significantly for patients receiving topiramate at 100 mg/d (-2.1, P =.008) and topiramate at 200 mg/d (-2.4, P<.001) vs placebo (-1.1). Statistically significant reductions (P<.05) occurred within the first month with topiramate at 100 and 200 mg/d. The responder rate was significantly greater with topiramate at 50 mg/d (39%, P =.01), 100 mg/d (49%, P<.001), and 200 mg/d (47%, P<.001) vs placebo (23%). Reductions in migraine days were significant for the 100-mg/d (P =.003) and 200-mg/d (P<.001) topiramate groups. Rescue medication use was reduced in the 100-mg/d (P =.01) and 200-mg/d (P =.005) topiramate groups. Adverse events resulting in discontinuation in the topiramate groups included paresthesia, fatigue, and nausea. CONCLUSION: Topiramate showed significant efficacy in migraine prevention within the first month of treatment, an effect maintained for the duration of the double-blind phase.

Adolescent↗

PubMed2004

The tension headache component of chronic daily headache.

Chronic daily headache (CDH) is an overarching term that includes multiple types of frequent primary headaches that are not trigeminal-autonomic cephalgias. The components of typical CDH can be divided into a more severe or "big" headache and a less severe or "little" headache. The big headaches tend to have features of migraine while the little headaches have features of tension-type headache (TTH). Whether this represents a spectrum or continuum or whether it is the superimposition of two unique headache entities is open to debate. For subjects with big and little headache, the concept that the TTH component is part of a spectrum seems likely. Subjects with only TTH and no migrainous component seem to represent a different entity, pure chronic TTH. These patients have a daily moderate headache that is poorly responsive to current therapies and appears to be a different TTH than the migraine tension type of CDH. The TTH component of CDH may represent multiple subdivisions of TTH.

Chronic Disease↗

PubMed2004

Posttraumatic Headache.

Posttraumatic headache (PTH) is divided into acute and chronic groups whose management and prognosis are clearly different. Although IHS criteria stipulate that PTH should have an onset within 2 weeks of the trauma, it has been observed that a headache linked to the trauma can start later. PTH can be clinically divided into the following groups: migraine-like headache, tension-type-like headache, cluster-like headache, cervicogenic-like headache, and others. Based on these clinical distinctions, therapy can be administered accordingly. However, the distinction is relative and numerous clinical features may be common to all. There seems to be a weak inverse relationship between the severity of the head trauma and the occurrence of a PTH, especially chronic. A holistic approach is not only useful but it is necessary for a therapeutic success. Early and aggressive treatment and empathy are essential to the patient's improvement. Prompt recognition and treatment of laceration, peripheral nociceptive sources such as cervical joint displacement, vascular factors, may diminish chronicity. Neuromodulation of pain with prophylactic agents is recommended early. Although it is less necessary for the acute PTH, it will be crucial for the chronic form and should be initiated no later than 2 months cut-off time between acute and chronic PTH. Recognition and treatment of psychiatric factors such as depression and anxiety will lessen the risk of chronicity. Analgesic rebound-withdrawal headache commonly is seen in chronic PTH. This must be corrected rapidly because it can protract the headache and render other inappropriate therapeutic measures inefficient.

Journal Article↗

PubMed2004

Differences in mortality by radiation monitoring status in an expanded cohort of Portsmouth Naval Shipyard workers.

Studies of leukemia and lung cancer mortality at the Portsmouth Naval Shipyard (PNS) have yielded conflicting results. In an expanded cohort of PNS workers employed between 1952 and 1992 and followed through 1996, the all-cause standardized mortality ratio (SMR) was 0.95 (95% confidence interval, 0.93-0.96). Employment duration SMRs were elevated with confidence intervals excluding 1.00 for lung cancer, esophageal cancer, and all cancers combined. Leukemia mortality was as expected overall, but standardized rate ratio analyses showed a significant positive linear trend with increasing external radiation dose. The role of solvent exposures could not be evaluated. Findings differed by radiation monitoring subcohort, with excess asbestosis deaths limited to radiation workers and several smoking-related causes of death higher among nonmonitored workers. At PNS, asbestos exposure and possibly smoking could be nonrandomly distributed with respect to radiation exposure, suggesting potential for confounding in internal analyses of an occupational cohort.

Adult↗

PubMed2003

Antidepressants in the treatment of migraine headache.

Antidepressants, particularly tricyclic antidepressants, have been a mainstay in the prophylactic therapy of migraine. The tricyclic antidepressants amitriptyline, nortriptyline, and doxepin have been the major agents for prophylactic treatment of migraine. These cause significant side effects in some patients. The high-affinity selective serotonin reuptake inhibitors and other newer antidepressants have been disappointing and much less effective in the treatment of migraine. In patients who are depressed with severe migraine, a tricyclic antidepressant may treat both conditions; however, the addition of a newer atypical antidepressant may be needed.

Antidepressive Agents↗