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Biomedical subjects

L Carroll

Publications and source records attributed to L Carroll.

At least 19 recordsLinked to original sources
PubMed2003

Melanocortins and their receptors and antagonists.

The melanocortins are a group of small protein hormones derived by post-translational cleavage of the proopiomelanocortin (POMC) gene product. The known melanocortin hormones include alpha-melanocyte stimulating hormone (MSH), beta-MSH, gamma-MSH and adrenocorticotropic hormone (ACTH). Five melanocortin receptors (MCIR through to MC5R) have been identified and most of these show tissue-specific expression patterns, as well as different binding affinities for each of the melanocortin hormones. The central melanocortin system consists of alpha-MSH, agouti-related protein (AGRP), MC3R and MC4R. AGRP and alpha-MSH are believed to be the natural antagonist and agonist respectively of MC3R and MC4R. This central melanocortin system is thought to play a fundamental role in the control of feeding and body weight. Knock-out mice models and genetic studies have pointed to the importance of the melanocortins in complex human pathways such as pigmentation, lipolysis, food intake, thermogenesis, sexual behaviour, memory and inflammatory response. Recently the melanocortins and their receptors have been the target for drug-based treatment of human physiological processes. MC3R and MC4R are likely targets for controlling body weight; MCIR may be used in the treatment of inflammation and MC2R for the treatment of glucocortical deficiency. A role for MCSR still remains unclear, but the evidence suggests an exocrine gland function.

Agouti Signaling Protein↗
PubMed2002

The squatters and the blowflies.

Cutaneous myiasis in Australian sheep became an increasing problem in the early years of the 20th century after the import of the wrinkly Vermont Merinos and the introduction of Lucillia cuprina. WE Abbott, a successful pastoralist in New South Wales at that time, wrote a little-known and unusual description of early methods of control: a parody based on an episode in Through the Looking Glass by Lewis Carroll. The plight of struck sheep and the lives and times of Abbott, several other pastoralists and the entomologists of the New South Wales Department of Agriculture are illuminated as the Walrus and the Carpenter walk again across the hills and pastures of New South Wales.

Animals↗
PubMed2001

Size and fluctuating asymmetry of morphometric characters in mice: their associations with inbreeding and t-haplotype.

Fluctuating asymmetry (FA), a ubiquitous type of asymmetry of bilateral characters, often has been used as a measure of developmental instability in populations. FA is expected to increase in populations subjected to genetic stressors such as inbreeding or environmental stressors such as toxins or parasites, although results have not always been consistent. We tested whether FA in four skeletal size characters and mandible shape was greater in a population of wild-derived mice reared in the laboratory and subjected to one generation of inbreeding (F = 0.25) versus that in an outbred group (F = 0.00). FA did not significantly differ between the inbred and outbred groups, despite the fact that these two groups differed dramatically in fitness under seminatural population conditions. As far as we know, this is the first study to evaluate the relationship between FA and inbreeding in wild house mice, and our general conclusion is opposite that of earlier work on laboratory inbred strains of mice and their hybrids. Size for two of the characters was significantly less in inbreds than in outbreds, however, and there was a significant difference between inbreds and outbreds in the signed differences of right and left sides in one character (humerus length). Some of the mice in both groups also were heterozygous or homozygous carriers of the t-complex. Because mice carrying this chromosome 17 variant are known to have reduced fitness, we also tested whether they had greater FA than mice carrying non-t-haplotypes. The overall level of a composite FA index calculated from all four characters was in fact significantly higher in the t-bearing mice. These combined results suggest that FA is not a generally sensitive proxy measure for fitness, but can be associated with fitness reductions for certain genetic stressors.

Analysis of Variance↗
PubMed2001

A systematic review of the prognosis of acute whiplash and a new conceptual framework to synthesize the literature.

STUDY DESIGN: Systematic review of prognostic studies of acute whiplash. OBJECTIVES: To update the systematic review on the prognosis of acute whiplash published by the Quebec Task Force on Whiplash-Associated Disorders and to propose a new conceptual framework to conduct systematic reviews on prognosis. SUMMARY OF BACKGROUND DATA: In 1995, the Quebec Task Force published a systematic review of the literature on whiplash and concluded that its prognosis is favorable. However, few prognostic factors were identified. Recent studies have added to this knowledge, and there is a need to update the review conducted by the Quebec Task Force. METHODS: A bibliographic search of four electronic databases was performed to identify prognostic studies of acute whiplash published after 1995. The literature was appraised with standard review criteria. The consistency of evidence across studies was assessed. A conceptual framework was designed to classify the literature according to methodologic quality, target population, and phases of investigation. RESULTS: Thirteen cohort studies were included in the review. The framework used in this study demonstrates that most of the recent prognostic studies are descriptive in nature. The prognosis of acute whiplash varies according to the population sampled and the insurance/compensation system under which individuals are allowed to claim benefits. Besides age, gender, baseline neck pain intensity, baseline headache intensity, and baseline radicular signs and symptoms, there is little consistency in the literature about the prognostic factors for the recovery of whiplash. CONCLUSIONS: Scant knowledge about the prognosis of whiplash has been gained since the release of the Quebec Task Force report. However, it is becoming obvious that the insurance and compensation systems have a large impact on recovery from acute whiplash injuries. The conceptual framework used in this study demonstrates that large cohort studies investigating a wide range of prognostic factors are necessary to improve the understanding of this problem.

Concept Formation↗
PubMed2001

Pragmatic randomised controlled trial to evaluate guidelines for the management of infertility across the primary care-secondary care interface.

OBJECTIVE: To investigate the effect of clinical guidelines on the management of infertility across the primary care-secondary care interface. DESIGN: Cluster randomised controlled trial. SETTING: General practices and NHS hospitals accepting referrals for infertility in the Greater Glasgow Health Board area. PARTICIPANTS: All 221 general practices in Glasgow; 214 completed the trial. INTERVENTION: General practices in the intervention arm received clinical guidelines developed locally. Control practices received them one year later. Dissemination of the guidelines included educational meetings. MAIN OUTCOME MEASURES: The time from presentation to referral, investigations completed in general practice, the number and content of visits as a hospital outpatient, the time to reach a management plan, and costs for referrals from the two groups. RESULTS: Data on 689 referrals were collected. No significant difference was found in referral rates for infertility. Fewer than 1% of couples were referred inappropriately early. Referrals from intervention practices were significantly more likely to have all relevant investigations carried out (odds ratio 1.32, 95% confidence interval 1.00 to 1.75, P=0.025). 70% of measurements of serum progesterone concentrations during the midluteal phase and 34% of semen analyses were repeated at least once in hospital, despite having been recorded as normal when checked in general practice. No difference was found in the proportion of referrals in which a management plan was reached within one year or in the mean duration between first appointment and date of management plan. NHS costs were not significantly affected. CONCLUSIONS: Dissemination of infertility guidelines by commonly used methods results in a modest increase in referrals having recommended investigations completed in general practice, but there are no detectable differences in outcome for patients or reduction in costs. Clinicians in secondary care tended to fail to respond to changes in referral practice by doctors. Guidelines that aim to improve the referral process need to be disseminated and implemented so as to lead to changes in both primary care and secondary care.

Cost-Benefit Analysis↗
PubMed2001

The association between neck pain intensity, physical functioning, depressive symptomatology and time-to-claim-closure after whiplash.

Time-to-claim-closure is a common outcome in cohort studies of whiplash injuries. However, its relationship to health recovery is unknown. We investigated the association between neck pain, physical functioning, depressive symptomatology and time-to-claim-closure in a Saskatchewan cohort of 5398 whiplash claimants in 1994-1995. Participants were surveyed five times over 1 year. In 1995, the insurance system changed from tort to no-fault, eliminating compensation for pain and suffering. Under tort, a 10-point increase in pain reduced the claim-closure rate by 13-24% while a 10-point increase in physical functioning increased it by 17%. Depressive symptomatology reduced the claim-closure rate by 37%. Under no-fault, a 10-point increase in pain reduced the claim-closure rate by 18% while a 10-point increase in physical functioning increased it by 10-35%. The presence of depressive symptomatology reduced the claim-closure rate by 36%. The results suggests lower pain, better function and the absence of depressive symptoms are strongly associated with faster time-to-claim-closure and recovery after whiplash, independent of the insurance system.

Accidents, Traffic↗
PubMed2001

The treatment of neck and low back pain: who seeks care? who goes where?

BACKGROUND: Neck and low back pain are leading causes of morbidity and health care utilization. However, little is known about the characteristics that differentiate those who seek from those who do not seek health care for their pain. OBJECTIVES: The objectives of this study were to: 1) describe health care utilization for neck and back pain; 2) determine the characteristics of individuals seeking health care for neck and back pain; and 3) identify the characteristics of patients who consult medical doctors, chiropractors, or both. DESIGN: Population-based cross-sectional mailed survey. SUBJECTS: Subjects were randomly selected adults from the Saskatchewan Health Insurance and Registration File. MEASURES: Demographic, socio-economic, general health, comorbidity, health-related-quality-of-life, pain severity and health care utilization data were collected. The main outcome was whether subjects with prevalent neck or low back pain visited a health care provider in the previous month. RESULTS: Twenty-five percent of individuals with neck or low back pain visited a health care provider. Seeking health care was associated with disabling neck or back pain, digestive disorders, worse bodily pain and worse physical-role-functioning. Compared with medical patients, fewer chiropractic patients lived in rural areas or reported arthritis, but they reported better social and physical functioning. More patients consulting both providers reported disabling neck or back pain. CONCLUSIONS: Individuals seeking care for neck or back pain have worse health status than those who do not seek care. Patients consulting chiropractors alone report fewer comorbidities and are less limited in their activities than those consulting medical doctors.

Adult↗
PubMed2000

The factors associated with neck pain and its related disability in the Saskatchewan population.

STUDY DESIGN: Population-based, cross-sectional mailed survey. OBJECTIVE: To identify factors associated with neck pain and its related disability in Saskatchewan adults. SUMMARY OF BACKGROUND INFORMATION: Little is known about the etiology of neck pain and its related disability. Previous cross-sectional population-based studies have suggested that neck pain may be associated with age, female gender, lower socioeconomic status, physically demanding work, and other comorbidities. METHODS: The Saskatchewan Health and Back Pain Survey was mailed to 2184 randomly selected Saskatchewan adults 20 to 69 years of age. Fifty-five percent of the study population participated. The survey collected demographic, socioeconomic, and health-related information. Neck pain and its related disability was classified into four categories using the Chronic Pain Questionnaire: no neck pain (Grade 0), low intensity/low disability neck pain (Grade I), high intensity/low disability neck pain (Grade II), and high disability neck pain (Grades III-IV). Polytomous logistic regression was used to identify associations between demographic, socioeconomic, and health-related variables and various grades of neck pain severity. RESULTS: Of the 1131 respondents, 54% had experienced neck pain at some point in the 6 months before the survey, and almost 5% were highly disabled by neck pain. The prevalence of Grade I neck pain was lower in individuals with low education attainment, but higher for those reporting headaches, low back pain, better general health, and a history of neck injury resulting from a motor vehicle collision, some of whom may have received compensation for their injury. Grade II neck pain was strongly associated with headache, low back pain, and a history of neck injury during a motor vehicle collision and weakly associated with digestive disorders and current cigarette smoking. Grades III-IV neck pain was strongly associated with low back pain, headaches, cardiovascular disorders, digestive disorders, and a history of neck injury during a motor vehicle collision. CONCLUSION: This study suggests that important associations exist between comorbidities, a past history of neck injury resulting from a motor vehicle collision, and graded neck pain. Importantly, individuals who are significantly disabled by neck pain also have comorbidities that have a moderate or severe impact on their health, suggesting that chronic disorders tend to cluster in some individuals.

Accidents, Traffic↗
PubMed2000

Is a lifetime history of neck injury in a traffic collision associated with prevalent neck pain, headache and depressive symptomatology?

The objective of this study is to determine whether independent associations exist between a history of neck injury related to a motor vehicle collision and: (1) graded neck pain in the past 6 months; (2) headaches in the past 6 months and; (3) depressive symptomatology during the past week. We used data from the Saskatchewan Health and Back Pain Survey, a population-based cross-sectional survey mailed to a stratified random sample of 2184 Saskatchewan adults aged 20-69 years. Fifty-five percent of the eligible population participated. The exposure was collected by asking subjects whether they had ever injured their neck in a motor vehicle collision. The outcomes: 6-month prevalence of graded neck pain, 6-month prevalence headache and depressive symptomatology during the past week were measured with valid and reliable questionnaires. Sixteen percent of the study sample reported a lifetime history of neck injury in a traffic collision. The association between neck injury and the outcomes was determined from polytomous and binary multivariate logistic regression with adjustment for age, gender and other covariates. A history of neck injury was positively associated with low intensity/low disability neck pain (OR = 2.81; 95% CI 1.81-4.37), positively associated with high intensity/low disability neck pain (OR = 4.46; 95% CI 2.49-4.99) and with disabling neck pain (OR = 3.30; 95% CI 1.48-7.39). Similarly, we found a positive association between a history of neck injury in a motor vehicle collision and headaches that moderately/severely impact on one's health (OR = 2.09; 95% CI 1.27-3.44). No association was found between neck injury and depressive symptomatology (OR = 0.84; 95% CI 0.50-1.40). Our cross-sectional analysis suggests that neck pain and severe headaches are more prevalent in individuals with a history of neck injury from a car collision. However, the results should not be used to infer a causal relationship between whiplash and chronic neck pain and headaches.

Accidents, Traffic↗
PubMed2000

9:45-10:00. Positron Emission Tomography (PET) is Superior to Computerized Tomography (CT) for Metastatic Staging in Melanoma Patients.

PET provides diagnostic information currently not available with traditional imaging. Retrospective analysis was performed of 104 patients with primary or recurrent melanoma who underwent PET for staging to determine sensitivity/specificity compared to body CT. 157 PET and 70 CT scans were analyzed with a mean follow up of 26 months. Metastatic events were confirmed with positive histology (73%) or documented disease progression.PET demonstrated 86% sensitivity and 97% specificity in 41 patients with metastasis. CT showed 57% sensitivity and 70% specificity in 30 patients with metastasis. Exclusion of areas not evaluated on CT (head, neck/supraclavicular, and extremities) increased CT sensitivity to 68%. Fifty-three patients underwent 67 consecutive CT and PET scans that detected 132 metastases in 30 individuals. PET detected a greater percentage of metastases (83%) compared to CT (56%), and specifically, in the soft tissue, neck, peripheral/mediastinal/intraabdominal lymph nodes, and small bowel. PET detected 100% of mediastinal metastasis while CT detected only 67%. Surprisingly, PET detected 84% of lung parenchymal metastasis compared to 72% with CT.PET is more sensitive and specific than CT for detection of melanoma metastasis and should be considered the primary staging study upon suspicion of recurrent disease. PET shows greater ability to detect soft tissue, small bowel, and lymph node metastasis that do not meet criteria designated as abnormal by CT. Likewise, CT does not routinely evaluate the supraclavicular area, neck, or upper/lower extremities. However, even when these sites are excluded from comparative analysis, PET is superior to CT in detecting melanoma metastasis.

Journal Article↗
PubMed1999

Is there a healthy worker effect for cancer incidence among women in Sweden?

BACKGROUND: Our aim was to evaluate whether there is a healthy worker effect (HWE) for cancer incidence among women. HWE is a bias found in occupational studies that compare rates of disease among employed people to disease rates for the general population, which includes unemployed people (who may be less healthy than those who are employed). METHODS: Data from the 1960 and 1970 Swedish censuses were used to identify all 1,659,940 Swedish women who were employed in either year. They were followed during 1971-1989 through linkages to the national cancer and death registers. Standardized incidence ratios (SIRs) were computed comparing employed women to the 1,627,873 women who were not employed in either 1960 or 1970. RESULTS: For the 545,857 women employed in both 1960 and 1970, the SIR for all cancers combined was 1.05 (1.04-1.06). When specific cancer sites were analyzed separately, the highest cancer risks were for cancers of the lung and bladder (SIR = 1.2) and reproductive organs (breast, ovary, endometrium, and cervix SIR = 1.1). Overall cancer risks were highest among full-time workers, younger workers, urban workers, and workers with the highest socioeconomic status (based on the woman's job title). CONCLUSIONS: These results show no general HWE for cancer incidence among employed Swedish women.

Adult↗
PubMed1999

Androgen receptors in two androgen-mediated, sexually dimorphic characters of frogs.

The presence/absence of androgen receptors is examined in two sexually dimorphic features of frogs: the nuptial pad and the external oblique muscle. Immunohistochemistry reveals that both males and females possess androgen receptors in these tissues. Males have a higher density of immunopositive nuclei in the oblique muscle than do females. The presence of androgen receptors in both male and female tissues is consistent with results from hormone experiments in which androgen supplements induce the expression of a nuptial pad and enlarge the external oblique muscles in castrated males and ovariectomized females.

Analysis of Variance↗
PubMed1998

The Saskatchewan Health and Back Pain Survey. The prevalence of neck pain and related disability in Saskatchewan adults.

STUDY DESIGN: Population-based, cross-sectional mailed survey. OBJECTIVE: To determine the lifetime, period, and point prevalence of neck pain and its related disability among Saskatchewan adults and investigate the presence and strength of nonresponse bias. SUMMARY OF BACKGROUND DATA: In Europe, the lifetime and point prevalence of neck pain is almost as high as the prevalence of low back pain. Similarly, chronic neck pain is highly prevalent and a common source of disability in the working-age population. However, no studies specifically have documented the prevalence of neck pain and its related disability in North America. METHODS: The Saskatchewan Health and Back Pain Survey was mailed to 2184 randomly selected Saskatchewan adults aged 20-69 years. Fifty-five percent of the study population participated. The presence of nonresponse bias was investigated through logistic regression and wave analysis. The Chronic Pain Questionnaire was used to classify the severity of chronic neck pain. RESULTS: The age-standardized lifetime prevalence of neck pain is 66.7% (95% confidence interval, 63.8-69.5), and the point prevalence is 22.2% (95% confidence interval, 19.7-24.7). The age-standardized 6-month prevalence of low-intensity and low-disability neck pain is 39.7% (95% confidence interval, 36.7-42.7), whereas it is 10.1% (95% confidence interval, 8.2-11.9) for high-intensity and low-disability neck pain and 4.6% (95% confidence interval, 3.3-5.8) for significantly disabling neck pain. The prevalence of low-intensity and low-disability neck pain decreases with age. More women experience high-disability neck pain than men. Wave analysis suggests that the point prevalence and 6-month prevalence of high-intensity and low-disability neck pain are overestimated in this survey. CONCLUSION: This cross-sectional study shows that neck pain is highly prevalent in Saskatchewan and that it significantly disables 4.6% (95% confidence interval, 3.3-5.8) of the adult population.

Adult↗
PubMed1998

Good health care: patient and professional perspectives.

Many health needs assessment exercises are professionally led, employing complex epidemiological methods. An alternative method that gives valuable information about patient preferences is a forced-choice questionnaire, which this study used in five practices in the West of Scotland. In each practice, patient-centred care was the most highly valued attribute of service provision.

Attitude of Health Personnel↗
PubMed1997

Hormonal induction of thumb pads and the evolution of secondary sexual characteristics of the Southeast Asian fanged frog, Rana blythii.

The fanged frogs of Southeast Asia do not express most of the hormone-dependent secondary sexual characteristics such as thumb pads that are common to other ranid frogs. At the same point in the evolutionary history of the group that these androgen-mediated characteristics are lost, male parental care first evolves. This behavior is often correlated with low androgen levels. Prior work indicates that in one of the fanged frogs, Rana blythii, adult males have low androgen levels compared to North Temperate species of Rana. This leads to the question of whether these low androgen levels are related to the unusual male parental care and the lack of expression of the thumb pad and other hormone-dependent secondary sexual characteristics in this species. We tested that hypothesis by examining the effects of exogenous dihydrotestosterone supplements on the expression of thumb pads in Rana blythii. Dihydrotestosterone injections appear to stimulate the expression of the thumb pad in R. blythii. These results support the hypothesis that low androgen levels are involved in the loss of the thumb pad in R. blythii. This work provides an example of how mapping characters on phylogenies can be a powerful approach for gaining insights into proximate physiological mechanisms of selection at the evolutionary level.

Animals↗
PubMed1997

Affinity-purified, mixed monospecific crotalid antivenom ovine Fab for the treatment of crotalid venom poisoning.

SUBJECT OBJECTIVE: To test the efficacy and safety of a new antivenom, affinity-purified, mixed monospecific crotalid antivenom ovine Fab, in human subjects with minimal or moderate crotalid envenomation. METHODS: We conducted a prospective multicenter clinical trial of 11 patients 10 years or older with progressive manifestations after mild to moderate crotalid snakebite. After giving their consent, subjects received four to eight vials of study drug and were then repeatedly examined over 48 hours and at 7 and 14 days after discharge. Each patient's clinical condition was evaluated serially with the use of a validated severity score, as well as on the basis of the investigator's assessment. RESULTS: In all 11 subjects to the antivenom was judged by the investigator to have had a beneficial response. The severity score for each patient remained the same or decreased over the first 4 hours. However, two subjects demonstrated worsened condition 12 to 15 hours after antivenom administration. In no subject did an allergic reaction develop. CONCLUSION: In this patient group, affinity-purified, mixed monospecific crotalid antivenom ovine Fab was associated with a halt of progressive crotalid venom poisoning. Initial safety data are promising but must be addressed further in subsequent studies.

Adolescent↗
PubMed1997

Self-narcissism and interpersonal attraction to narcissistic others.

In the first of a two-part study, 172 participants completed a questionnaire on personality and career preferences. Items from the Narcissism Scale of the Million Clinical Multiaxial Inventory were embedded in this questionnaire as well as a series of bogus items. In the second session conducted three weeks later, participants watched a videotaped dramatization of either a male or female enacting a narcissistic role and completed a modified version of the First Impressions Questionnaire and an item assessing mood. The narcissism scores of participants obtained during Part 1 were paired with their respective ratings of the target person on the modified-First Impressions Questionnaire and mood. Contrary to predictions participants' scores on narcissism did not affect their first impressions of persons enacting a narcissistic role. Participants who viewed the male role player rated him as less attractive than those who watched the female, while participants who watched the female target reported greater negative mood scores than those who watched the male target.

Adolescent↗