Biomedical subjects

J Patterson

Publications and source records attributed to J Patterson.

At least 19 recordsLinked to original sources

PubMed2006

Modification of the home environment for the reduction of injuries.

BACKGROUND: Injury in the home is extremely common, accounting for around a third of all injuries. The majority of injuries of children under five and people aged 75 and over, occur at home. Multifactorial injury prevention interventions have been shown to reduce injuries in the home. However, few studies have focused specifically on the impact of physical adaptations to the home environment and the effectiveness of such interventions needs to be ascertained. OBJECTIVES: To review the evidence for the effect on injuries of modification of the home environment with a primary focus on interventions to reduce physical hazards. SEARCH STRATEGY: We searched The Cochrane Library, MEDLINE, EMBASE, National Research Register and other specialised databases. We also scanned conference proceedings and reference lists. In addition, we contacted experts and trialists in the field. The searches were not restricted by language or publication status. The searches were last updated in December 2004. SELECTION CRITERIA: Randomised controlled trials. DATA COLLECTION AND ANALYSIS: All abstracts were screened by two authors for relevance, outcome and design. Two authors independently assessed methodological quality and extracted data from each eligible study. MAIN RESULTS: We found 18 published and one unpublished trials. Trials were not sufficiently similar to allow pooling of data by statistical analyses, so this review takes a narrative form. Studies were divided into three groups based on the primary population sample; children (five studies), older people (14 studies) and the general population/mixed age group (no studies). None of the studies focusing on children demonstrated a reduction in injuries that might have been due to environmental adaptation in the home; one study reported a reduction in injuries and in hazards but the two could not be linked. Of the 14 included studies in older people, none demonstrated a reduction in injuries due to hazard reduction, although two demonstrated a reduction in falls that could be due to hazard reduction. AUTHORS' CONCLUSIONS: There is insufficient evidence to determine the effects of interventions to modify environmental home hazards. Further interventions to reduce hazards in the home should be evaluated by adequately designed randomised controlled trials measuring injury outcomes. Recruitment of large study samples to measure effect must be a major consideration for future trials.

Accidents, Home↗

PubMed2006

Evidence for the early onset of aberrant promoter methylation in urothelial carcinoma.

There is evidence that carcinoma in situ (CIS) is the precursor of invasive urothelial carcinoma, a tumour characterized by frequent gene promoter methylation. The timing of altered DNA methylation is unknown in this pathway. Here we investigate gene methylation in 196 consecutive samples of normal urothelium, CIS, and tumours from 104 patients with both CIS and invasive urothelial carcinoma using quantitative methyl-sensitive polymerase chain reaction for six genes (p16, p14, E-cadherin, RARbeta2, RASSF1a, and GSTP1). Control normal urothelial samples from 15 patients with no history of urothelial carcinoma were also analysed. Immunohistochemistry established the expression of well-characterized CIS markers p53 and cytokeratin 20. Promoter methylation occurred frequently in both normal urothelium and CIS samples from patients with urothelial carcinoma, and increased with progression from normal to invasive urothelial carcinoma, at both specific loci (chi2 test: E-cadherin, p=0.0001; RASSF1a, p=0.003, RARbeta2, p=0.007, p16, p=0.024) and in general (methylation indices [t-test, p<0.0001]). Methylation was associated with cytokeratin 20 expression (t-test, p=0.004) and poor prognosis, and with increased progression to tumour death in patients whose CIS samples showed methylation, in comparison with those without methylation (log rank p<0.03). Promoter methylation occurs early in the urothelial carcinogenic pathway and appears to be a good biomarker of the invasive urothelial carcinoma phenotype.

Adult↗

PubMed2006

Incidence of Clostridium difficile-associated diarrhea before and after autologous peripheral blood stem cell transplantation for lymphoma and multiple myeloma.

Diarrhea is a major cause of morbidity and discomfort for patients undergoing high-dose chemotherapy and autologous peripheral blood stem cell transplantation (APBSCT). There are multiple causes of diarrhea in patients undergoing transplantation including antineoplastic chemotherapy, antimicrobials and infection, including Clostridium difficile as the most common pathogen involved. The purpose of this study was to determine the incidence of C. difficile-associated diarrhea (CDAD) 1 week before and 30 days after APBSCT, and to identify risk factors for the development of CDAD including diagnosis. Two hundred and forty-two patients underwent APBSCT for multiple myeloma and lymphoma between October 1996 and October 2001 in two teaching hospitals. Diarrhea was reported in 157 (64.9%) subjects. One hundred and thirty-five out of the 157 subjects were tested for the presence of C. difficile toxin A. These subjects constitute the study group. The incidence of CDAD was 15%. Two thirds of the patients who developed CDAD had multiple myeloma and one third had lymphoma; this difference did not attain statistical significance. The use of cephalosporins (P = 0.03) and the use of intravenous vancomycin (P = 0.02) were the only identified risk factors associated with the development of CDAD. Patients treated with paclitaxel as part of the mobilization regimen had a lower incidence of CDAD than patients who received hematopoietic growth factor only (P = 0.01).

Adult↗

PubMed2005

Parents' perceptions of the value of the Webster-Stratton Parenting Programme: a qualitative study of a general practice based initiative.

BACKGROUND: Parenting styles and parent-child relationships are a determinant of emotional and behavioural problems in children. Controlled trials of parenting programmes have been shown to be effective in helping parents of children with clinical levels of behaviour problems, but there is little research on the impact of such programmes in families where children's development falls in the 'normal' range. Also, such trials do not shed light on why or how programmes do, or do not, work, or how they might be improved. METHODS: A qualitative study of the impact of the Webster-Stratton 'Parents and Children Series' programme on participants in a controlled trial of this programme, whose children's behaviour was below average, but, for the majority, in the normal range. Data were gathered in interviews, open-ended questions on a questionnaire and tape recordings of group leader supervision sessions. RESULTS: Parents reported increased confidence, better relationships with their children, successful use of new behaviour management techniques and improvements in their children's behaviour as a result of the programme. One parent found the programme unsuitable because she was already using the techniques that were taught, and another parent felt the programme was designed for parents of younger children. Many parents reported that additional sessions would have been useful to consolidate what they had learnt, and some parents felt the course would have been more effective if their partners had attended. CONCLUSIONS: The Webster-Stratton Parenting Programme is useful for parents of 'normal' children as well as for parents of children whose behaviour is in the clinical range. Follow-up sessions and attendance by both parents might increase effectiveness. The findings of this study suggest greater benefits to parents and children than were apparent in the controlled trial.

Adaptation, Psychological↗

PubMed2005

Selected culturable enteric bacterial populations are modified by diet acidification and the growth promotant Tylosin.

AIMS: To determine the effect of diet acidification and an in-feed antibiotic growth promotant (Tylosin, Ty) on selected culturable bacterial populations in the gastrointestinal tract (GIT) of mice. METHODS AND RESULTS: Female C57Bl mice were given a standard diet supplemented with Acid Pak (AP) or Ty in the drinking water. After 21 days, lumen and adherent populations of Enterobacteriaceae, enterococci/streptococci, and lactic acid bacteria (LAB) from the ileum, caecum, colon and faeces were enumerated. General intestinal health was assessed by the frequency of haemolytic bacteria in the different intestinal compartments. Contrary to expectations, AP and Ty significantly increased haemolytic bacteria in the lumen of the caecum and colon (P<0.05). The small but significant growth-enhancing effect of Ty (P<0.05) was associated with decreases in enterococci/streptococci and surprisingly, LAB, as well as increases in coliforms. AP, which failed to improve growth rates, reduced coliforms, had limited effects on enterococci/streptococci, and specifically failed to promote the growth of LAB populations in all intestinal compartments. Ty supplementation was also associated with a significant increase in macrolide-resistant enterococci throughout the GIT. CONCLUSIONS: Dietary acidification is less effective than Ty in modulating the population dynamics of selected culturable populations of enteric bacteria. SIGNIFICANCE AND IMPACT OF THE STUDY: The mouse can provide a useful experimental model to examine the effects of new dietary supplements, formulations or regimes on changes in microbial population dynamics, including monitoring for antibiotic resistance.

Animals↗

PubMed2005

Report of an independent peer review of an acrylonitrile risk assessment.

A peer review panel made up of experts in toxicology, epidemiology, cancer mode of action (MOA), cancer mechanisms, carcinogenicity, genotoxicity, dose-response, US Environmental Protection Agency (EPA) cancer and noncancer methods, pharmacokinetic modeling and acrylonitrile, met on 22-23 September 2003 in Cincinnati, OH. The purpose of the meeting was to provide an independent review of a risk assessment of acrylonitrile that had been prepared by the Acrylonitrile Group (AN Group). Toxicology Excellence for Risk Assessment (TERA) organized the peer review and selected the panel. The panel discussed the toxicity and epidemiology literature of acrylonitrile and MOA information, and reached conclusions regarding its MOA, weight of evidence (WOE) for carcinogenicity, preferred approach for dose-response assessment and risk values. This paper summarizes the discussion and conclusions of the panel regarding the acrylonitrile assessment. Subsequent to the peer review, the authors of the acrylonitrile assessment revised their report and the panel reviewed the revised report. A manuscript of the revised assessment is being published in Regulatory Toxicology and Pharmacology.

Acrylonitrile↗

PubMed2004

HSV1716 injection into the brain adjacent to tumour following surgical resection of high-grade glioma: safety data and long-term survival.

Following standard treatment, the prognosis remains poor in patients with high-grade glioma and new therapies are urgently required. Herpes simplex virus 1716 (HSV1716) is an ICP34.5 null mutant that is selectively replication competent and shown to be safe and to replicate following injection into high-grade glioma. We demonstrate that following surgical resection, HSV1716 is safe when injected into the brain adjacent to excised tumour. In all, 12 patients with recurrent or newly diagnosed high-grade glioma underwent maximal resection of the tumour. HSV1716 was injected into eight to 10 sites around the resulting tumour cavity with the intent of infecting residual tumour cells. As clinically indicated, patients proceeded to further radiotherapy or chemotherapy. There has been no clinical evidence of toxicity associated with the administration of HSV1716. Longitudinal follow-up has allowed the assessment of overall survival compared to that of similar patients not treated with HSV1716. Three patients remain alive and clinically stable at 15, 18 and 22 months postsurgery and HSV1716 injection. Remarkably, the first patient in the trial, who had extensive recurrent disease preprocedure, is alive at 22 months since injection of HSV1716 and 29 months since first diagnosis. Imaging has demonstrated a reduction of residual tumour over the 22-month period despite no further medical intervention since the surgery and HSV1716 injection. In this study, we demonstrate that on the basis of clinical observations, there has been no toxicity following the administration of HSV1716 into the resection cavity rim in patients with high-grade glioma. The survival and imaging data, in addition to the lack of toxicity, give us confidence to proceed to a clinical trial to demonstrate efficacy of HSV1716 in glioma patients.

Adult↗

PubMed2004

Impact of a general practice based group parenting programme: quantitative and qualitative results from a controlled trial at 12 months.

AIMS: To test the effectiveness at one year of the Webster Stratton Parents and Children Series group parenting programme in a population sample of parents. METHODS: In a multicentre block randomised controlled trial, parents of children aged 2-8 years in 116 families who scored in the upper 50% on a validated behaviour inventory, took part in Webster-Stratton's 10 week parenting programme led by trained and supervised health visitors. The following outcome measures were used: Eyberg Child Behaviour Inventory, Goodman Strengths and Difficulties Questionnaire, General Health Questionnaire, Parenting Stress Index, Rosenberg Self Esteem Scale. RESULTS: The intervention significantly reduced child behaviour problems and improved mental health at immediate and 6 month follow ups. One year differences between control and intervention groups were not significant. Qualitative results suggest that these findings might be attributable in part to either Hawthorne effects or contamination of control group. At interview parents described ways in which the programme had improved their mental health. They reported gains in confidence and feeling less stressed. Some also reported beneficial changes in their own and their children's behaviour and improved relationships with their children. Some spoke of a need for further sessions to support the behaviour changes they had managed to make, and some the desire for attendance by both parents. CONCLUSIONS: Parenting programmes have the potential to promote mental health and reduce social inequalities, but further work is needed to improve long term effectiveness.

Child↗

PubMed2004

Regional CBF in chronic stable TBI treated with hyperbaric oxygen.

To investigate whether Hyperbaric Oxygen Therapy (HBO2) could improve neurologic deficits and regional cerebral blood flow (rCBF) in chronic traumatic brain injuries (TBI), the authors employed a nonrandomized control pilot trial. Five subjects, at least three years post head injury, received HBO2. Five head injured controls (HIC) were matched for age, sex, and type of injury. Five healthy subjects served as normal controls. Sixty-eight normal volunteers comprised a reference data bank against which to compare SPECT brain scans. HBO2 subjects received 120 HBO2 in blocks of 80 and 40 treatments with an interval five-month break. Normal controls underwent a single SPECT brain scan, HBO2, and repeat SPECT battery. TBI subjects were evaluated by neurologic, neuropsychometric, exercise testing, and pre and post study MRIs, or CT scans if MRI was contraindicated. Statistical Parametric Mapping was applied to SPECT scans for rCBF analysis. There were no significant objective changes in neurologic, neuropsychometric, exercise testing, MRIs, or rCBF. In this small pilot study, HBO2 did not effect clinical or regional cerebral blood flow improvement in TBI subjects.

Adult↗

PubMed2003

Modification of the home environment for the reduction of injuries.

BACKGROUND: Injury in the home is extremely common, accounting for around a third of all injuries. The majority of injuries of children under five and people aged 75 and over occur at home. Multi-factorial injury prevention interventions have been shown to reduce injuries in the home. However, few studies have focussed specifically on the impact of physical adaptations to the home environment and the effectiveness of such intervention needs to be ascertained. OBJECTIVES: To review the evidence for the effect on injuries of modification of the home environment with a primary focus on interventions to reduce physical hazards. SEARCH STRATEGY: We searched the following databases: APId, ASSIA, British Nursing Index, CINAHL, Cochrane Library databases, Dissertation Abstracts, EMBASE, HealthSTAR, ICONDA, ISI Science (and Social Science) Citation Index, MEDLINE, National Research Register, PREMEDLINE, SIGLE and Urbadisk. Conference proceedings and reference lists were scanned. Experts in the field and trialists were contacted. Searches were not restricted to English language. Handsearching of relevant journals was not conducted. SELECTION CRITERIA: Randomised controlled trials, non-randomised controlled trials, controlled before-and-after studies and interrupted time series studies. DATA COLLECTION AND ANALYSIS: All abstracts were screened by two reviewers for relevance, outcome and design. Two reviewers independently evaluated methodological quality and extracted data from each eligible study. MAIN RESULTS: We found 28 published trials and one unpublished study. Trials were not sufficiently similar to allow for the combination of data by statistical analyses, so this review takes a narrative form. Studies were divided into three groups based on the primary population sample: children, older people and the general population. None of the 11 childhood studies demonstrated a reduction in injuries that might have been due to environmental adaptation in the home. One study reported a reduction in injuries and in hazards but the two could not be linked. The majority of studies used hazard reduction as the outcome. Of the 15 studies in older people, none demonstrated a reduction in injuries due to hazard reduction, although two demonstrated a reduction in falls that could be due to hazard reduction. In the mixed age group there were two trials; neither demonstrated an effect on injuries. REVIEWER'S CONCLUSIONS: There is insufficient evidence to determine the effects of interventions to modify environmental home hazards. Further interventions to reduce hazards in the home should be evaluated by adequately designed randomised controlled trials measuring injury outcomes. Recruitment of large study samples to measure effect may be a major consideration for future trials.

Accidents, Home↗

PubMed2002

Performance of a hybrid central venous catheter utilized for both peripheral blood stem cell harvest and transplant support of patients undergoing autologous peripheral blood stem cell transplantation.

Patients undergoing autologous peripheral blood stem cell transplantation (PBSC) frequently require the sequential insertion of two central venous catheters, one for leukapheresis and one for transplant support. Hybrid catheters suitable for leukapheresis and long-term use have been increasingly used, but there is limited information regarding their performance and complication rate. The purpose of this study was to determine the performance of the Pheres-Flow hybrid catheter when utilized for both leukapheresis and transplant support, with particular emphasis on the incidence of infectious and occlusive complications. We prospectively analyzed the performance of 92 catheters in 82 consecutive patients who underwent autologous peripheral blood stem cell (PBSC) transplantation. Occlusion was the most frequent complication of this catheter with 29% of the patients experiencing difficulty drawing blood or infusing fluids. Infection was another frequent complication. Twenty-two percent of patients developed catheter-related bloodstream infections and 15 catheters had to be removed because of proven or suspected infection that did not respond to antibiotic therapy. Nevertheless, 77% of patients were able to complete leukapheresis and transplant support with only one catheter. We conclude that the utilization of the Pheres-Flow catheter for both leukapheresis and transplant support is feasible, but that new strategies need to be developed to decrease the incidence of occlusive and infectious complications of hybrid catheters.

Adult↗

PubMed2002

Need and demand for parenting programmes in general practice.

AIMS: To establish the prevalence of behaviour problems and the level of interest in parenting programmes in a population sample of parents of children aged 2-8 years, and to assess to what extent they are associated with socioeconomic factors. METHODS: Postal survey of parents of children aged 2-8 years registered with three general practitioner surgeries; 70% response rate. RESULTS: One fifth of parents from this population sample were experiencing difficulties with their children's behaviour. While behaviour problems were more prevalent in the manual social classes, "need" was high across all social groups. Just under a fifth of parents reported prior attendance at a parenting programme and 58% expressed interest in attending in the future. Interest in attending a parenting programme was not class related, but was predicted by the age of the eldest child and the existence of behaviour problems. CONCLUSION: Behaviour problems are an important public health issue. Findings support the use of a non-selective approach to the provision of parenting programmes in the UK.

Attitude to Health↗

PubMed2002

Improving mental health through parenting programmes: block randomised controlled trial.

AIMS: To assess the effectiveness of a parenting programme, delivered by health visitors in primary care, in improving the mental health of children and their parents among a representative general practice population. METHODS: Parents of children aged 2-8 years who scored in the upper 50% on a behaviour inventory were randomised to the Webster-Stratton 10 week parenting programme delivered by trained health visitors, or no intervention. Main outcome measures were the Eyberg Child Behaviour Inventory and the Goodman Strengths and Difficulties Questionnaire to measure child behaviour, and the General Health Questionnaire, Abidin's Parenting Stress Index, and Rosenberg's Self Esteem Scale to measure parents' mental health. These outcomes were measured before and immediately after the intervention, and at six months follow up. RESULTS: The intervention was more effective at improving some aspects of the children's mental health, notably conduct problems, than the no intervention control condition. The Goodman conduct problem score was reduced at immediate and six month follow up, and the Eyberg Child Behaviour Inventory was reduced at six months. The intervention also had a short term impact on social dysfunction among parents. These benefits were seen among families with children scoring in the clinical range for behaviour problems and also among children scoring in the non-clinical (normal) range. CONCLUSION: This intervention could make a useful contribution to the prevention of child behaviour problems and to mental health promotion in primary care.

Child↗

PubMed2002

Application of locally available materials for the treatment of organic polluted water.

Several types of water treatment technologies including adsorption are now being used to treat polluted water. In this paper the removal of phenol by adsorption will be discussed. Activated carbons are successfully applied for purification of potable water and the removal of organic pollutants in wastwater. This paper is concerned with a low cost approach to treating waste water that is significant especially for those countries where oil palm is an available agricultural product like Malaysia, Ivory Coast, Nigeria, Thailand, Papua New Guinea. In the coastal region coconut is an available agricultural product and activated carbon prepared using coconut shell is also an economical method of water treatment. The materials used in this study were Commercial Activated Carbon (CAC), prepared from coconut shell and Modified Oil Palm Shell (MOPAS) of 1 to 2 mm diameters. The surface area of CAC and MOPAS was 38.5 m2/g and 38.2 m2/g respectively and the iodine number was determined as 674 and 454 for CAC and MOPAS, respectively. From the study the result shows above 70% removal efficiency for 5 mg/L and 40% removal efficiency for 20 mg/L of phenol solution. The performance efficiency will be discussed based on batch test, following Freundlich adsorption isotherm. The results indicate that CAC exhibits a higher adsorptive capacity (Kf of 0.079) as compared to MOPAS (Kf of 0.048). Hence a better removal efficiency for CAC at lower concentration of phenol. Results from column tests show a better adsorptive capacity for CAC (2.73) as compared to MOPAS (2.48).

Adsorption↗

PubMed2001

Epidemiology of invasive Streptococcus pneumoniae infections in the United States, 1995-1998: Opportunities for prevention in the conjugate vaccine era.

CONTEXT: Pneumococcal polysaccharide vaccine is recommended for elderly persons and adults with certain chronic illnesses. Additionally, a recently licensed pneumococcal 7-valent conjugate vaccine has been recommended for use in young children and could dramatically change the epidemiology of pneumococcal disease. OBJECTIVES: To assess pneumococcal disease burden in the United States, estimate the potential impact of new vaccines, and identify gaps in vaccine recommendations. DESIGN AND SETTING: Analysis of data from the Active Bacterial Core Surveillance (ABCs)/Emerging Infections Program Network, an active, population-based system in 9 states. PATIENTS: A total of 15 860 cases of invasive pneumococcal disease occurring between January 1, 1995, and December 31, 1998. MAIN OUTCOME MEASURES: Age- and race-specific pneumoccocal disease incidence rates per 100 000 persons, case-fatality rates, and vaccine preventability. RESULTS: In 1998, overall incidence was 23.2 cases per 100 000, corresponding to an estimated 62 840 cases in the United States. Incidence was highest among children younger than 2 years (166.9) and adults aged 65 years or older (59.7). Incidence among blacks was 2.6 times higher than among whites (95% confidence interval [CI], 2.4-2.8). Overall, 28.6% of case-patients were at least 65 years old and 85.9% of cases in this age group were due to serotypes included in the 23-valent polysaccharide vaccine; 19.3% of case-patients were younger than 2 years and 82.2% of cases in this age group were due to serotypes included in the 7-valent conjugate vaccine. Among patients aged 2 to 64 years, 50.6% had a vaccine indication as defined by the Advisory Committee on Immunization Practices (ACIP). The case-fatality rate among patients aged 18 to 64 years with an ACIP indication was 12.1% compared with 5.4% for those without an indication (relative risk, 2.2; 95% CI, 1.7-2.9). CONCLUSIONS: Young children, elderly persons, and black persons of all ages are disproportionately affected by invasive pneumococcal disease. Current ACIP recommendations do not address a subset of persons aged 18 to 64 years but do include those at highest risk for death from invasive pneumococcal disease.

Adolescent↗

PubMed2001

A brief observational measure for urban neighborhoods.

There is growing recognition that neighborhood context contributes to the health and well-being of residents over and above individual characteristics and health behaviors. However, few published reports exist of methods for documenting neighborhood characteristics which are easily administered with minimal outlay of resources. In this paper, we present the development of a brief observational method for urban neighborhoods relevant to the health and well-being of families and children. Data from a socieconomically diverse group of urban neighborhoods are used to create theoretically grounded measures of neighborhood context, and the utility of these measures for discriminating between and within urban neighborhoods is demonstrated.

Crime↗

PubMed2001

GLI1 localization in the germinal epithelial cells alternates between cytoplasm and nucleus: upregulation in transgenic mice blocks spermatogenesis in pachytene.

The zinc finger transcription factor GLI1 is the mediator of signaling by members of the Hedgehog (Hh) family. Male mice in which Desert hedgehog (Dhh), an Hh homologue expressed in Sertoli cells of the testis, was knocked out are sterile, suggesting that the Dhh/GLI1 pathway plays a role in spermatogenesis. Using an antiserum raised against human GLI1, we found that during the first round of spermatogenesis, GLI1 expression is initially cytoplasmic, then shifts to the nuclei of Sertoli and germ cells, and finally shifts back to the cytoplasm. In the adult mouse testis, GLI1 expression localized to the nuclei of germ cells, beginning with pachytene cells and persisting through round spermatids. Localization of GLI1 in elongating spermatids shifted from the nucleus to the cytoplasm and became associated with microtubules. We also examined a line of transgenic mice that overexpressed human GLI1. Male mice in this line were sterile. Spermatogenesis was blocked at the pachytene stage, and a subset of the morphologically indistinguishable pachytene cells underwent apoptosis. Patched-2, which is a Dhh receptor, and Fused, another component of the signal transduction pathway, are expressed in Leydig cells and in primary and secondary spermatocytes. Expression of GLI1 in the same cell types as Patched-2 and Fused and the disruption of spermatogenesis by GLI1 overexpression suggest that GLI1 is the mediator of the Dhh signal in the testis, and that it may be a regulator of spermatogenesis.

Animals↗

PubMed2001

Characterization of the microglial response to cerebral ischemia in the stroke-prone spontaneously hypertensive rat.

Stroke-prone spontaneously hypertensive rats (SHRSP) sustain more ischemic damage after middle cerebral artery occlusion than do their reference strain, the Wistar-Kyoto rat (WKY). The cause of increased stroke sensitivity is still under investigation. In general, SHRSP display a greater response to inflammatory stimuli than do WKY. Because inflammatory cells may influence the extent of damage in experimental stroke, this study has investigated the acute inflammatory response to focal ischemia in SHRSP and WKY. Adult male SHRSP (n=5) and WKY (n=5) were anesthetized and underwent distal middle cerebral artery occlusion. After 24 hours of recovery, infarct volume, neutrophil counts, and activated microglia counts were performed. SHRSP displayed more ischemic damage than did WKY (135+/-4.7 versus 102+/-4.7 mm(3) [mean+/-SEM], P<0.005). Brain neutrophil counts were extremely low in both strains. SHRSP displayed significantly more activated microglia than did WKY in the ipsilateral hemisphere (respective SHRSP versus WKY values [mean+/-SEM] were 88+/-3.6 versus 51+/-3.4 per mm(2) for the cortical peri-infarct region [P<0.005] and 183+/-7.9 versus 156+/-3.7 per mm(2) for the infarct core [P<0.05]) and in the contralateral hemisphere (eg, respective SHRSP versus WKY values were 102+/-3.2 versus 50+/-3.1 per mm(2) for the sensorimotor cortex [P<0.0001]). No neutrophils and very few activated microglia were found within the brains of naive rats. However naive SHRSP possessed more microglia (resting and activated) than did naive WKY. This study demonstrates a more pronounced microglial response to focal ischemia in SHRSP compared with WKY and provides evidence of a potential role for inflammatory processes in response to ischemic damage.

Animals↗