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Robert Walker

Publications and source records attributed to Robert Walker.

47 records · Page 3Linked to original sources
PubMed2003

Inducible cytokine gene expression in the brain in the ME7/CV mouse model of scrapie is highly restricted, is at a strikingly low level relative to the degree of gliosis and occurs only late in disease.

The temporal course of cerebral cytokine gene expression was investigated in the ME7/CV murine scrapie model to determine any association with neuropathological events. Analysis by RNase protection assay (RPA) demonstrated no transcripts for ILs 2, 3, 4, 5, 6, 7, 10, 12p40 and 13, granulocyte macrophage colony-stimulating factor, IFN-gamma or lymphotoxin-alpha at any time during the course of this disease. Transcripts for transforming growth factor-beta 1 were constitutively expressed in both control and scrapie-infected brain and were elevated at terminal disease. RPA and quantitative real-time RT-PCR detected low levels of transcripts for IL-1 alpha, IL-1 beta and TNF alpha in scrapie-infected brain but only IL-1 beta was elevated consistently in all mice studied. Although glial cell activation within the hippocampus was evident from 100 days post-infection (p.i.), elevated IL-1 beta transcripts (and immunoreactivity) were evident from 180 days p.i., around the time of hippocampal pyramidal neuron loss, and increased steadily thereafter to reach a 3.5-fold increase at terminal disease. Even at their maximum, levels of these transcripts were disproportionately low relative to the degree of glial cell activation. It is concluded that cytokine gene expression in the ME7 scrapie-infected mouse brain, relative to the degree of reactive gliosis, is highly restricted, temporally late and disproportionately low.

Animals↗
PubMed2003

Rural and small-town attitudes about alcohol use during pregnancy: a community and provider sample.

CONTEXT: While there has been considerable research on prenatal alcohol use, there have been limited studies focused on women in rural and small-town environments. PURPOSE: This 2-part study examines gender differences in attitudes and perceived barriers to intervention in large community sample of persons living in rural and small-town environments in Kentucky (n = 3,346). The study also examines rural/small-town prenatal service providers' perceptions of barriers to assessment and intervention with pregnant substance abusers (n = 138). METHODS: Surveys were administered to a convenience sample of employees and customers from 16 rural and small-town community outlets. There were 1503 males (45%) and 1843 females (55%) ranging in age from under 18 years old to over 66 years old. Surveys also were mailed to prenatal providers in county health departments of the 13-county study area, with 138 of 149 responding. FINDINGS: Overall results of the community sample suggest that neither males nor females were knowledgeable about the harmful effects of alcohol use during pregnancy. Results also indicate substantial gender differences in alcohol attitudes, knowledge, and perceived barriers. Further, prenatal care providers identified several barriers in assessment and treatment of pregnant women with alcohol use problems in rural and small-town communities, including lack of knowledge and comfort with assessment as well as a lack of available and accessible treatment for referrals.

Alcohol Drinking↗
PubMed2002

The management and outcome of occluded haemodialysis access: a retrospective audit.

AIM: To identify best clinical practice for the management of occluded haemodialysis access. Surgery or percutaneous thrombolysis with or without angioplasty, has been used for the management of clotted haemodialysis access, with variable reported success rates. Concerns over high morbidity rates and delays in achieving satisfactory patent arterio-venous (AV) access, led to a retrospective audit of all patients with occluded haemodialysis vascular access between 1 June 1995 and 30 June 2001. METHODS: Data recorded included type of access, procedure used, outcome, complications and hospital stay. RESULTS: There were 45 episodes occurring in 17 patients. 33 of the 45 episodes occurred in synthetic grafts. Eleven of the 17 patients had multiple episodes (range 2 to 11), nine of whom had synthetic grafts. Forty three of the 45 episodes initially underwent DSA on presentation. There was a low success rate with thrombolysis, with only 20 cases effective in re-establishing dialysis. Surgery revision was required to re-establish effective dialysis in 25 of the 45 episodes. Six of 43 thrombolysis procedures experienced a major complication related to excessive bleeding. Primary patency was slightly better for surgery compared with thrombolysis (4.9 months versus 3.8 months). Temporary catheters were inserted for dialysis in 19 of 45 episodes and remained for a mean of 5.8 days. Four patients had a major episode of catheter-related sepsis. Two patients required admission to the Intensive Care Unit (ICU) for management of their sepsis. Patients who failed thrombolysis and required surgery had a prolonged stay, averaging 8.2 days. This was associated with a marked increase in hospital costs. The average cost for successful thrombolysis was $1976, compared with $5348 where surgery was subsequently required. Costing of surgical intervention alone was similar to that of thrombolysis. CONCLUSION: Surgery with dedicated vascular surgeons remains the safest, most rapid and most effective approach to treating occluded dialysis AV fistulae and grafts.

Adult↗
PubMed2002

Age-dependency in hunting ability among the Ache of eastern Paraguay.

This paper examines changes in hunting ability across the lifespan for the Ache of eastern Paraguay. Hunting ability is decomposed into two components-finding prey and probability of kill upon encounter- and analyzed for important prey species. Results support the argument that skill acquisition is an important aspect of the human foraging niche with hunting outcome variables reaching peaks surprisingly late in life, significantly after peaks in strength. The implications of this study are important for modeling the role of the human foraging niche in the co-evolution of various outstanding human life history characteristics such as large brains, long lifespans, and extended juvenile periods.

Adolescent↗
PubMed2002

Stalker profiles with and without protective orders: reoffending or criminal justice processing?

Research indicates that stalking is an extension of intimate partner violence. The overall purpose of this study was to better understand stalkers by examining the association between a protective order history and the court's processing of subsequent stalking, and to examine patterns of reoffending. This study examined a sample of 346 males who were charged with stalking in 1999 in one state. Subjects were partitioned into three groups: (1) males without protective orders; (2) males with one prior protective order; and (3) males with two or more prior protective orders. Almost two-thirds of the stalkers had a protective order against them at some point in the study, suggesting that stalking is associated with intimate partner violence. Results also found a linear trend with many of the criminal justice involvement variables and protective order history prior to 1999. Those charged with first-degree stalking were more likely to be found guilty initially, and about one-third of all three study groups had the initial felony stalking charge amended. Of those charged with second-degree stalking, only 7% of the group with two or more protective orders was initially found guilty, which was substantially less than the other two groups. And, when all the amendment dispositions were considered, there were no significant differences by group in guilty and dismissed dispositions for the index stalking charge. Further, consistent with previous criminal justice involvement, the group with two or more protective orders was more likely to have subsequent felony charges than the other two groups. Implications are discussed.

Adolescent↗
PubMed2002

Child custody evaluations and domestic violence: case comparisons.

The literature indicates that witnessing domestic violence is harmful to children, that them is a high overlap between domestic violence and child abuse, and that safety is an important issue for separating women because separation from abusive partners is a particularly dangerous time for victims of domestic violence. Further, child custody is often a contentious issue in domestic violence cases. Child custody evaluations are typically used to assist courts in deciding custody when custody is disputed and when the best interests of the child are unclear. The concept of "best interests of the child" does not specify evaluation techniques or approaches, however, and while custody evaluation standards generally address the best interests of the child, they offer little guidance in high-risk situations such as parental domestic violence. In addition, there has been limited research focused on understanding the custody evaluation process or the degree to which practitioners differ in their procedures and reporting for cases with and without parental domestic violence. This study is one of the first to examine characteristics of disputed custody cases and their custody evaluation reports differences between domestic violence and non-domestic violence cases. This study selected a 60% random sample of cases with custody evaluations in Fiscal Year 1998 and 1999 (n = 82 cases). Out of the 82 cases, 56% (n = 46) met criteria for classification into the domestic violence group and 44% (n = 36) did not. In general, results indicated that although there were some important differences in court records between cases with and without domestic violence, there were only minor differences between custody evaluation reported process and recommendations for the two groups. Implications for research and practice are discussed.

Adult↗
PubMed2002

[Fibromyalgia and anxiety disorder.].

OBJECTIVE: The etiology of fibromyalgia is unclear. The diagnosis is based on widespread pain and muscular tenderness, but other symptoms often occur, such as sleep disturbance, excessive anxiety and fatigue and concentration difficulties. All these symptoms can occur in generalized anxiety disorder. The aim of this study was to assess whether fibromyalgia is associated with other diagnoses, particularly anxiety disorder. MATERIAL AND METHODS: The study includes all those receiving full disability pension on the 1st of December 2001 as ascertained by the disability register at the State Social Security Institute of Iceland. Information was obtained from the register on gender, age and diagnoses of the disability beneficiaries. Diagnoses were compared between two groups of disability beneficiaries - an index group with fibromyalgia and a comparison group without that diagnosis. There were 716 women in each group. We also compared diagnoses among the women who had fibromyalgia as primary diagnosis in the index group and among all women who had anxiety/depression as primary diagnosis. RESULTS: In the index group fibromyalgia was the single registered diagnosis in only 6.8% of cases, while 38.3% of the comparison group had a single registered diagnosis. There was a significant difference between the two groups in terms of the number of diagnoses by disease category (p<0.0001). Among individual categories of disease, the only category that showed a significant excess in the index group was mental disorders (p<0.0001). Women with fibromyalgia as a primary diagnosis were compared with women with a primary diagnosis of anxiety or depression in terms of distribution of the numbers of diagnoses per person. The distribution pattern was similar. CONCLUSIONS: The probability of having a mental disorder, especially an anxiety disorder, is significantly higher amongst women with fibromyalgia as compared to other women with full disability pension. This indicates an association between fibromyalgia and anxiety, an association which needs to be properly addressed in the treatment of this disorder.

English Abstract↗
PubMedDate not supplied

Modeling growth and senescence in physical performance among the ache of eastern Paraguay.

This article seeks to partially fill a paucity of available data on physical performance in hunter-gatherer societies. Quantitative data are presented on various physical performance measures conducted on the Ache of eastern Paraguay, hunter-gatherers up to the 1970s and now part-time foragers and horticulturists. The performance battery was conducted on most individuals over 10 years of age, allowing for cross-sectional examination of growth and senescence patterns across the lifespan for both sexes. These measures tend to display steep ascents and peak in the early 20s with slight declines thereafter with age for males, whereas females demonstrate peaks in performance earlier in life, with lower or no senescence rates thereafter. The result is a convergence in physical performance between men and women at later ages. We suggest that the female physiology faces reproductive constraints to performance early in life but shifts allocation to increased work output later in life during the long human postmenopausal stage. In contrast, the male physiology maximizes work output in early adult life. These schedules of physical performance are contrasted with schedules of food production ability, which tend to occur later in life, and therefore imply that skill rather than strength alone is an important component of the human foraging niche.

Adolescent↗
PubMedDate not supplied

Growth rates and life histories in twenty-two small-scale societies.

This study investigates variation in body growth (cross-sectional height and weight velocity) among a sample of 22 small-scale societies. Considerable variation in growth exists among hunter-gatherers that overlaps heavily with growth trajectories present in groups focusing more on horticulture. Intergroup variation tends to track environmental conditions, with societies under more favorable conditions displaying faster growth and earlier puberty. In addition, faster/earlier development in females is correlated with higher mortality. For example, African "Pygmies," Philippine "Negritos," and the Hiwi of Venezuela are characterized by relatively fast child-juvenile growth for their adult body size (used as a proxy for energetic availability). In these societies, subadult survival is low, and puberty, menarche, and first reproduction are relatively early (given their adult body size), suggesting selective pressure for accelerated development in the face of higher mortality. In sum, the origin and maintenance of different human ontogenies may require explanations invoking both environmental constraints and selective pressures.

Adolescent↗
PubMedDate not supplied

Head injury among drug abusers: an indicator of co-occurring problems.

Alcohol and other drug use has been associated with traumatic brain injury both as a contributing factor to the injury and as a complicating factor for rehabilitation. Brain injury is associated with an increase in mental health and other problems that may be related to drug and alcohol abuse and that may influence recovery. This study examined self-reports of 661 drug-abusing inmates with self-reported head injury, health problems and mental health problems. Three groups were examined for this study: those having no head injury, one head injury, and two or more head injuries. Results indicate that inmates with head injuries had a significantly greater number of health problems, higher levels of alcohol and marijuana use, and significantly more mental health problems including depression, anxiety, suicidal thinking, and difficulties in concentrating and controlling violent behavior. This study suggests that questions regarding head injuries during assessment may identify drug abusers who need a treatment approach that accommodates their co-occurring problems and difficulties with processing and complying with treatment interventions.

Adult↗