Efficacy of rifampicin combination therapy for the treatment of enterococcal infections assessed in vivo using a Galleria mellonella infection model

Enterococci are a leading cause of healthcare-associated infection worldwide and display increasing levels of resistance to many of the commonly used antimicrobials, making treatment of their infections challenging. Combinations of antibiotics are occasionally employed to treat serious infections, allowing for the possibility of synergistic killing. The aim of this study was to evaluate the effects of different antibacterial combinations against enterococcal isolates using an in vitro approach and an in vivo Galleria mellonella infection model. Five Enterococcus faecalis and three Enterococcus faecium strains were screened by paired combinations of rifampicin, tigecycline, linezolid or vancomycin using the chequerboard dilution method. Antibacterial combinations that displayed synergy were selected for in vivo testing using a G. mellonella larvae infection model. Rifampicin was an effective antibacterial enhancer when used in combination with tigecycline or vancomycin, with minimum inhibitory concentrations (MICs) of each individual antibiotic being reduced by between two and four doubling dilutions, generating fractional inhibitory concentration index (FICI) values between 0.31 and 0.5. Synergy observed with the chequerboard screening assays was subsequently observed in vivo using the G. mellonella model, with combination treatment demonstrating superior protection of larvae post-infection in comparison with antibiotic monotherapy. In particular, rifampicin in combination with tigecycline or vancomycin significantly enhanced larvae survival. Addition of rifampicin to anti-enterococcal treatment regimens warrants further investigation and may prove useful in the treatment of enterococcal infections whilst prolonging the clinically useful life of currently active antibiotics.

Implementation of a community greenhouse in a remote, sub-Arctic First Nations community in Ontario, Canada: a descriptive case study

INTRODUCTION

Food insecurity is prevalent in northern communities in Canada and there is a movement to improve food security through both the re-vitalization of traditional harvesting practices as well as through sustainable agriculture initiatives. Gardening in northern communities can be difficult and may be aided by a community greenhouse. The objective of this project was to conduct a descriptive case study of the context and process surrounding the implementation of a community greenhouse in a remote, sub-Arctic First Nations community in Ontario, Canada.

METHOD

Data sources included semi-directed interviews with a purposive and snowball sample of key informants (n=14), direct observations (n=32 days), written documentation (n=107), and photo-documentation (n=621 total). Digital photographs were taken by both a university investigator during community visits and a community investigator throughout the entire project. The case study was carried out over 33 months; from early 2009 until October of 2011. Thematic data analyses were conducted and followed a categorical aggregation approach.

RESULTS

Categories emerging from the data were appointed gardening-related themes: seasons, fertile ground, sustainability, gardeners, ownership, participant growth, and sunshine. Local champions were critical to project success. Uncertainty was expressed by several participants regarding ownership of the greenhouse; the local community members who championed the project had to emphasize, repeatedly, that it was community owned. Positive outcomes included the involvement of many community members, a host of related activities, and that the greenhouse has been a learning opportunity to gain knowledge about growing plants in a northern greenhouse setting. A strength of the project was that many children participated in greenhouse activities.

CONCLUSIONS

Community and school greenhouse projects require local champions to be successful. It is important to establish guidelines around ownership of a greenhouse and suitable procedures for making the building accessible to everyone without compromising security. Implementing a greenhouse project can engage community members, including children, and provide a great learning opportunity for gardeners in a remote, northern community.

Abstract P2-11-19: Expression of folate receptor alpha in ductal carcinoma in situ of the breast and comparison with that of invasive ductal carcinoma

Background: We have previously shown that the expression of Folate receptor alpha (FRA) is associated with high grade ER-/PR- or triple negative (TN) invasive ductal carcinoma of the breast. The aim of the current study is to investigate the expression pattern of FRA in a cohort of ductal carcinoma in situ (DCIS), analyze its relationship with different clinicopathological features and expression of several key biomarkers, and compare these findings to our previous data on invasive ductal carcinoma (IDC).

Methods: Ninety-eight cases of DCIS of the breast diagnosed between 1997 and 2008 in our institution were identified, reviewed and 6 blocks of tissue microassays (TMA) were constructed. The association between the expression of FRA (≥10% designed as positive expression) and the clinicopathologic features, the expression of ER, PR, HER2 and Ki-67, and the clinical outcome were evaluated, and these results were compared to those from IDC (399/430 cases with informative data). Results: Among the 98 cases of DCIS in TMA, 88 cases were informative. The expression rate of FRA was 21% for DCIS, less than the 29% seen in IDC. Expression of FRA was associated with high nuclear grades (42%), though less frequently than with IDC (52%). FRA expression was also associated with ER negativity (46%), PR negativity (33%) and high Ki-67 expression (50%) in DCIS, although significantly less than in IDC (75%, 63%, and 56%, respectively for negative ER and PR, and high Ki-67). Also, only 50% of ER/PR negative, TN and basal-like DCIS expressed FRA, significantly lower than that of IDC (74%, 80% and 80%, respectively). Due to the limited cases of DCIS, we did not demonstrate a significant difference in disease-free survival between FRA positive and negative tumors (p-value = 0.1792), although we did observe that IDC with FRA expression was significantly associated with a worse disease-free survival (p-value = 0.04).

Comparison between FRA expression between DCIS and IDC FRA≥10% in DCISFRA≥10% in IDCp-value 88 cases399 cases Nuclear 342%52%0.0185ER negative46%75%0.0442PR negative33%63%0.0214HER2 3+31%37%0.7003ER-/PR-50%74%0.0973Triple Negative50%80%0.1622Basal-Like50%80%0.1739

Conclusion: Our data demonstrates that FRA expression is associated with high nuclear grade, ER/PR negative and TN DCIS, though at a significantly lower rate than was observed in IDC, suggesting a possible role for this receptor in early breast carcinogenesis. There are differences in the rates of FRA expression between DCIS and IDC, suggesting that FRA may be one of the key molecules involved in progression of DCIS to IDC.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-11-19.

Abstract P2-11-20: Evaluation of folate receptor alpha expression in breast cancer by immunohistochemistry: Analysis with three different cut-off points

Background: Folate receptor alpha (FRA) is a newly recognized molecule that is selectively expressed in certain types of solid tumors, and several targeted therapies against FRA have shown promise in clinical trials for treating FRA-expressing ovarian and lung cancer. FRA has been shown to be selectively expressed in ER/PR negative and triple negative (TN) breast cancer; tumor types which would benefit from FRA targeted therapy. With these FRA-targeted therapies becoming available, correctly identifying eligible patients is very important. Currently, the cut off points for FAR expression by immunochemical (IHC) analysis have not been uniform. The commonly used cut points for expression that have been reported included 5%, 10% and the M score (using both staining intensity (3+, 2+, and 1+) and percentage of cells 0-100% (X, Y, Z for each staining intensity) in the equation (M-score = [3X+2Y+1Z]/ 6). The aim of the current study is to investigate these 3 most frequently used cut off points for FRA IHC analysis, in an effort to identify the one that is the most clinically relevant. Methods: 430 cases of infiltrating ductal carcinoma diagnosed between 1997 and 2008 in our institution were identified, reviewed, and 25 blocks of tissue microassays (TMA) were constructed. The association between the expression of FRA by IHC analysis, the clinicopathologic features, expression of ER, PR, HER2 and Ki-67, and the clinical outcome of these tumors were evaluated. Three cut off points (≥5%, ≥10% and M score of ≥10) were compared. 5% and 10% were scored as percent of membrane/cytoplasmic staining of the tumor cells regardless of the staining intensity while the M score takes into consideration both percentage and intensity of the staining of tumor cells.Results: Among the 430 cases studied, 399 cases had informative data from IHC analysis. The positive rates for FRA were 33%, 29% and 17%, respectively, for 5%, 10% and M score 10 as the positive cut off. All three cut off points were associated with significantly higher tumor grades and higher nodal status; they were also associated significantly with ER negativity, PR negativity or high proliferation rates (Ki-67≥15%) (P-values <0.0001 in all), and ER-/PR-, TN, or Basal-like tumors (p-values <0.0001 in all). Also, they were all significantly associated with worse disease-free survival with the p-values of 0.027, 0.026, and 0.009, for 5%, 10% and M score 10, respectively.

FRA positive rates with three different cut off points FRA ≥5% (%)FRA ≥10% (%)FRA M-score ≥10 (%)Age >50 (year)32%28%17%Tumor size <2 (cm)28%26%16%Histologic grade 351%47%32%LN status >041%34%20%ER negative77%74%56%PR negative66%63%46%HER2 3+48%37%26%Ki67>15%60%56%41%ER-/PR-77%74%54%Triple Negative82%80%60%Basal-like82%80%59%

Conclusion: Our data demonstrates that all three cut off points (5%, 10% and M score 10) could effectively separate breast tumors into subgroups where FRA expression correlated with specific pathologic features and a worse disease-free survival compared with FRA negative tumors. Using an M score of >10 as the cut off for FRA may be most specific method for determining the prognostic significance of FRA expression in breast cancer.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-11-20.

Capillary pressure may predict preclinical changes in the eye

AIMS/HYPOTHESIS

Microvascular dysfunction is associated with end-organ damage. Macular oedema is an important component of diabetic retinopathy. Macular thickness can be accurately quantified by optical coherence tomography (OCT), enabling accurate assessment of the macular prior to clinically apparent abnormalities. We investigated whether macular (fovea) thickness in non-diabetic individuals is related to the microvascular variables controlling fluid filtration across a blood vessel wall, in particular capillary pressure and the microvascular filtration capacity (Kf).

METHODS

We recruited 50 non-diabetic individuals (25 men, 25 women; age range: 26-78 years; BMI range: 20-46 kg/m(2)). Fovea thickness was assessed by OCT. Microvascular assessments included: finger nailfold capillary pressure; Kf; microvascular structural assessments, i.e. skin vasodilatory capacity, minimum vascular resistance (MVR) and microvascular distensibility; and endothelial function.

RESULTS

At 214.6 (19.9) microm (mean [SD]), fovea thickness was within normal range. Capillary pressure, adjusted for BMI, was associated with fovea thickness (standardised beta 0.573, p = 0.006, linear regression). Fovea thickness was not associated with Kf, microvascular structural assessments or endothelial function. Capillary pressure was still associated with fovea thickness when adjusted for microvascular variables (Kf, vasodilatory capacity, MVR, microvascular distensibility or endothelial function), or for risk factors for diabetes (systemic blood pressure, insulin sensitivity, inflammation, glycaemic status and lipids) and age.

CONCLUSIONS/INTERPRETATION

Capillary pressure, a key determinant of movement of fluid across a blood vessel wall, is associated with fovea thickness in non-diabetic individuals. This suggests that with regard to potential preventative or therapeutic targets, attention should be directed at the mechanisms determining retinal microvascular pressure.

Adiposity is a major determinant of plasma levels of the novel vasodilator hydrogen sulphide

AIMS/HYPOTHESIS

Hydrogen sulphide is a recently identified endogenous endothelium-dependent vasodilator. Animal models of diabetes have shown that low plasma H(2)S levels are associated with marked endothelial dysfunction and insulin resistance. However, human studies on H(2)S and vascular function in health and disease are lacking.

METHODS

Plasma was obtained from male patients with type 2 diabetes (n = 11), overweight (n = 16) and lean (n = 11) volunteers. H(2)S levels were determined by zinc trap spectrophotometry. Anthropometric measurements (BMI/waist:hip ratio), lipid profile, systemic blood pressure, biochemical indices of diabetes (fasting glucose, insulin sensitivity, Hb(1Ac)) and microvascular function (minimum vascular resistance) were determined.

RESULTS

Median plasma H(2)S levels (25th, 75th percentiles) in age-matched lean, overweight and type 2 diabetes individuals were 38.9 (29.7, 45.1) micromol/l, 22.0 (18.6, 26.7) micromol/l and 10.5 (4.8, 22.0) micromol/l, respectively. Median plasma H(2)S levels were significantly lower in patients with type 2 diabetes compared with lean (p = 0.001, Mann-Whitney) and overweight participants (p = 0.008). Median plasma H(2)S levels in overweight participants were significantly lower than in lean controls (p = 0.003). Waist circumference was an independent predictor of plasma H(2)S (R (2) = 0.423, standardised beta: -0.650, p < 0.001). This relationship was independent of diabetes, which only contributed a further 5% to the model (R (2) = 0.477). Waist circumference or other measures of adiposity (waist:hip ratio/BMI) remained independent predictors of plasma H(2)S after adjustment for systolic blood pressure, microvascular function, insulin sensitivity, glycaemic control and lipid profile.

CONCLUSIONS/INTERPRETATION

Plasma H(2)S levels are reduced in overweight participants and patients with type 2 diabetes. Increasing adiposity is a major determinant of plasma H(2)S levels.

Improvements in circulating cholesterol, antioxidants, and homocysteine after dietary intervention in an Australian Aboriginal community

BACKGROUND

Poor nutrition contributes to high rates of coronary heart disease among Australian Aboriginal populations. Since late 1993, the Aboriginal community described here has operated a healthy lifestyle program aimed at reducing the risk of chronic disease.

OBJECTIVE

We evaluated the effectiveness of a community-directed intervention program to reduce coronary heart disease risk through dietary modification.

DESIGN

Intervention processes included store management policy changes, health promotion activities, and nutrition education aimed at high-risk individuals. Dietary advice was focused on decreasing saturated fat and sugar intake and increasing fruit and vegetable intake. Evaluation of the program included conducting sequential, cross-sectional risk factor surveys at 2-y intervals; measuring fasting cholesterol, lipid-soluble antioxidants, and homocysteine concentrations; and assessing smoking status. Nutrient intakes were estimated from analysis of food turnover in the single community store.

RESULTS

There was a significant reduction in the prevalence of hypercholesterolemia (age-adjusted prevalences were 31%, 21%, and 15% at baseline, 2 y, and 4 y, respectively; P < 0.001). There were significant increases in plasma concentrations of alpha-tocopherol, lutein and zeaxanthin, cryptoxanthin, and beta-carotene across the population. Retinol and lycopene concentrations did not change significantly. Mean plasma homocysteine concentrations decreased by 3 micromol/L. There was no significant change in smoking prevalence between the 2 follow-up surveys. There was an increase in the density of fresh fruit and vegetables and carotenoids in the food supply at the community store.

CONCLUSION

This community-directed dietary intervention program reduced the prevalence of coronary heart disease risk factors related to diet.

Health status assessments using the Veterans SF-12 and SF-36: methods for evaluating otucomes in the Veterans Health Administration

This article describes a study in which the administration of two health surveys, the Veterans SF-36 and SF-12, by telephone and mail-out was used to assess the differences in the health surveys' costs and scores by mode of administration and determine which mode was cost-efficient. The study employed a crossover design: after 12 unsuccessful attempts to contact patients by telephone, the patients were administered the survey by mail, and after 2 unsuccessful mail-outs, up to three attempts were made to interview the patients by telephone. The analysis of the data showed that mail administration, with or without crossover to telephone, was more cost-efficient than telephone administration, having both lower average total and variable costs per completed questionnaire. Overall, telephone administration was about 30% more expensive that mail administration, primarily due to the cost of labor. The marginal cost of an additional completed Veterans SF-12 or Veterans SF-36 was also substantially lower for mail administration. Mail administration without crossover to telephone administration was the most cost-efficient strategy for administering both the Veterans SF-12 and SF-36. The results of this study strongly suggest the need to consider the mode of administration if questionnaires like the Veterans SF-12 or SF-36 are to be used to assess health outcomes within and across large health care systems.

Racial differences in the use of lumbar spine radiographs: results from the Veterans Health Study

STUDY DESIGN

We analyzed data from the Veterans Health Study, a longitudinal study of male patients receiving VA ambulatory care.

OBJECTIVE

To determine whether clinical differences and/or race account for disparities between white and nonwhite patients in the use of lumbar spine radiographs.

SUMMARY AND BACKGROUND DATA

Four hundred one patients with low back pain (LBP) receiving ambulatory care services in four VA outpatient clinics in the greater Boston area were followed for 12 months.

METHODS

Participants were mailed the Medical Outcome Study Short Form Health Survey (SF-36) and had scheduled interviews that included the completion of a low back questionnaire, a comorbidity index, and a straight leg raising (SLR) test. Using self-reported racial data, patients were grouped as whites (315 patients) and nonwhites (among whom 22 were black, 4 nonwhite Hispanics, and 1 other race).

RESULTS

Nonwhite patients had lumbar spine films more often (13 of 27, 48%) than white patients (87 of 315, 27%)(P = 0.02). Nonwhite patients had higher pain intensity scores than white patients (63 +/- 21 vs. 48 +/- 21, P < 0.01) and were more likely to have radiating leg pain (20 of 27, 76%; compared with 171 of 315, 55%; P = 0.01) than white patients. Nonwhite patients had worse physical functioning (P = 0.01), general health perception (P = 0.05), social functioning (P = 0.02), and role limitations because of emotional problems (P < 0.01). At higher LBP intensity level, nonwhite patients received more lumbar spine films (20 of 27, 74%) than did white patients (155 of 315, 50%)(P < 0.01). Among patients with positive SLR test, nonwhite patients also had lumbar spine films more often (5 of 22, 23%) than white patients (29 of 315, 11%) (P < 0.01). However, after adjusting for multiple clinical characteristics, race was no longer found to be an independent predictor of lumbar spine radiograph use. A positive SLR test remained to be associated with higher radiograph use, whereas better mental health status was associated with lower radiograph use.

CONCLUSIONS

There was greater use of lumbar spine radiographs by nonwhite patients compared with white patients. This remained true when patients were subcategorized by severity of LBP or SLR test. However, race had no influence when multiple clinical characteristics of the patients were controlled for simultaneously. This study demonstrates the importance of careful and comprehensive case-mix adjustment when assessing apparent differences in the use of medical services.

Knee effusions, popliteal cysts, and synovial thickening: association with knee pain in osteoarthritis

OBJECTIVE

To evaluate the association of effusions, popliteal cysts, and synovial thickening with knee symptoms in older persons with and without radiographic (XR) osteoarthritis (OA), using magnetic resonance imaging (MRI).

METHODS

Subjects with and without knee symptoms were recruited from Veterans Affairs and community sources. All had weight-bearing knee radiographs. Subjects were divided into 3 groups: Knee pain/XROA group had knee symptoms and radiographic OA; No knee pain/XROA group had no knee symptoms and radiographic OA; and No knee pain/no XROA group had no knee symptoms and a normal radiograph. A single knee was imaged using a 1.5 T MR scanner using T1 and T2 weighted and proton density SE imaging sequences. MRI were read for effusion, popliteal cysts, and synovial thickening.

RESULTS

The mean age of subjects was 67.0 years (66.6% male). We studied 381 subjects with Knee pain/XROA, 52 with No knee pain/XROA, and 25 with No knee pain/no XROA. The prevalence of moderate or larger effusions was: Knee pain/XROA 54.6%, No knee pain/XROA 15.6%, and No knee pain/no XROA 11.1%. Popliteal cysts were present in 33.0% of Knee pain/XROA subjects, 28.0% No knee pain/XROA, and 9.1% No knee pain/no XROA. After adjusting for the severity of radiographic OA, there was a difference between those with and without knee pain in prevalence of moderate or larger effusions (p < 0.001) and synovial thickening, independent of effusion (p < 0.001), but not in the prevalence of popliteal cysts. Further, among those in Knee pain/OA group, synovial thickening was associated with the severity of knee pain.

CONCLUSION

Effusions and popliteal cysts are common in middle aged and elderly people. After adjusting for the degree of radiographic OA, moderate or large effusions and synovial thickening were more frequent among those with knee pain than those without pain, suggesting these features are associated with the pain of knee OA. In those with knee symptoms, synovial thickening is uniquely associated with the severity of knee pain.

Differential expression of integrin alpha v and beta 3 in serosal tissue of human intraperitoneal organs and adhesion

OBJECTIVE

To assess the expression of integrin alpha v and beta 3 in the serosal tissue of intraperitoneal organs and adhesions in persons with and without adhesions.

DESIGN

Prospective study.

SETTING

Academic research centers.

PATIENT(S)

Fifty-seven patients undergoing abdominal or pelvic surgery.

MAIN OUTCOME MEASURE(S)

Integrin alpha v and beta 3 messenger RNA (mRNA) expression was evaluated by quantitative reverse transcription polymerase chain reaction.

RESULT(S)

The serosal tissue of the parietal peritoneum, uterus, fallopian tubes, ovary, and the large and small bowel, as well as peritoneal adhesions, skin, fascia, subcutaneous tissue, and omentum, expresses integrin alpha v and beta 3 mRNA. The level of alpha v and beta 3 mRNA expression varied among these tissues; expression of the former substance was highest in uterine serosa and lowest in the skin and small bowel, and expression of the latter substance was highest in the fallopian tubes and skin and lowest in the uterine serosa. Parietal peritoneum and adhesions express equal levels of integrin alpha v; however, integrin beta 3 expression was >100-fold lower in adhesions than in peritoneum. The level of integrin beta 3 expression in omentum, small and large bowels, and subcutaneous tissue was 100-fold to 10,000-fold lower than in other tissues.

CONCLUSION(S)

Serosal tissue of peritoneal organs and adhesions express variable levels of integrin alpha v and beta 3 mRNA. On the basis of such variation and the knowledge that tissue injury alters local integrin expression, integrins may play a key role in adhesion development, particularly in tissue with higher integrin expression.

Detecting radiographic knee osteoarthritis: what combination of views is optimal?

OBJECTIVE

The failure to image the patellofemoral joint or the posterior knee compartment when evaluating persons for knee osteoarthritis may result in missed cases. While the skyline view has been recommended due to more reproducible assessment of the patellofemoral joint space, the lateral view may be easier to acquire and provides different information. We evaluated the sensitivity of different combinations of X-ray views (anteroposterior and lateral; anteroposterior and skyline; all three views) in 377 persons with knee symptoms who had all three views available and had a definite osteophyte on at least one view.

RESULTS

Of the different views, skylines had to be excluded most often because the image of the patellofemoral joint was technically unsatisfactory. In the remaining knees, adding either a lateral or a skyline view to an anteroposterior view yielded roughly equal and high sensitivity (94-97%) when compared with the gold standard of a positive X-ray on any of the three views.

CONCLUSION

As long as at least an anteroposterior view and one image of the patellofemoral joint is obtained (either skyline or lateral), few cases with radiographic disease will be missed. For clinical or epidemiological studies the lateral view may be easier to acquire with high quality than the skyline view.

ACAT1 and ACAT2 membrane topology segregates a serine residue essential for activity to opposite sides of the endoplasmic reticulum membrane

A second form of the enzyme acyl-CoA:cholesterol acyltransferase, ACAT2, has been identified. To explore the hypothesis that the two ACAT enzymes have separate functions, the membrane topologies of ACAT1 and ACAT2 were examined. A glycosylation reporter and FLAG epitope tag sequence was appended to a series of ACAT cDNAs truncated after each predicted transmembrane domain. Fusion constructs were assembled into microsomal membranes, in vitro, and topologies were determined based on glycosylation site use and accessibility to exogenous protease. The accessibility of the C-terminal FLAG epitope in constructs was determined by immunofluorescence microscopy of permeabilized transfected cells. Both ACAT1 and ACAT2 span the membrane five times with their N termini in the cytosol and C termini in the ER lumen. The fourth transmembrane domain is located in a different region for each protein, placing the putative active site ACAT1 serine (Ser(269)) in the cytosol and the analogous residue in ACAT2 (Ser(249)) in the ER lumen. Mutation of these serines inactivated the ACAT enzymes. The outcome is consistent with the hypothesis that cholesterol ester formation by ACAT2 may be coupled to lipoprotein particle assembly and secretion, whereas ACAT1 may function primarily to maintain the balance of free and esterified cholesterol intracellularly.

Patient characteristics and patterns of use for lumbar spine radiographs: results from the Veterans Health Study

STUDY DESIGN

Longitudinal data from the Veterans Health Study, an observational study of male patients receiving Veterans Administration ambulatory care, were analyzed.

OBJECTIVE

To identify patient characteristics that predict different patterns in the use of lumbar spine radiographs.

SUMMARY AND BACKGROUND DATA

In this study, 401 patients with low back pain receiving ambulatory care services in four Veterans Administration outpatient clinics in the greater Boston area were followed for 12 months.

METHODS

Participants were mailed the Medical Outcome Study Short Form Health Survey and participated in scheduled interviews that included the completion of a low back questionnaire, a comorbidity index, and a straight leg raising test. Four groups of patients were defined according to the patterns of use for lumbar spine radiographs: prior use, repeat use, no use, and new use of lumbar spine radiographs. These groups were compared in terms of sociodemographics, comorbid conditions, low back pain intensity, radiating leg pain, straight leg raising, Medical Outcome Study Short Form Health Survey scores, and low back disability days.

RESULTS

The patients with new lumbar spine radiographs showed worse physical and psychological distress than the participants in the other three groups. In contrast, the patients with no lumbar spine radiographs reported minor physical impairment. Compared with patients who had no repeat radiographs, patients with repeat lumbar spine radiographs had similar scores on physical health, but they showed worse scores of mental health.

CONCLUSIONS

Both physical and psychological factors contribute to having new radiographic examinations, whereas psychological factors have increased importance in the repeat use of roentgenographic examinations. Repeat radiographs appear to be overused, judging by the severity of physical impairment as measured by low back pain intensity, the Medical OutcomeStudy Short Form Health Survey, and disability days.

Effectiveness of a community-directed 'healthy lifestyle' program in a remote Australian aboriginal community

OBJECTIVE

To assess the sustainability and effectiveness of a community-directed program for primary and secondary prevention of obesity, diabetes and cardiovascular disease in an Aboriginal community in north-west Western Australia.

METHOD

Evaluation of health outcomes (body mass index, glucose tolerance, and plasma insulin and triglyceride concentrations) in a cohort of high-risk individuals (n = 49, followed over two years) and cross-sectional community samples (n = 200 at baseline, 185 at two-year and 132 at four-year follow-ups), process (interventions and their implementation) and impact (diet and exercise behaviour).

RESULTS

For the high-risk cohort, involvement in diet and/or exercise strategies was associated with protection from increases in plasma glucose and triglycerides seen in a comparison group; however, sustained weight loss was not achieved. At the community level, significant reductions were observed in fasting insulin concentration but no change in prevalence of diabetes, overweight or obesity. Weight gain remained a problem among younger people. Sustainable improvements were observed for dietary intake and level of physical activity. These changes were related to supportive policies implemented by the community council and store management.

CONCLUSIONS

Community control and ownership enabled embedding and sustainability of program, in association with social environmental policy changes and long-term improvements in important risk factors for chronic disease.

IMPLICATIONS

Developmental initiatives facilitating planning, implementation and ownership of interventions by community members and organisations can be a feasible and effective way to achieve sustainable improvements in health behaviours and selected health outcomes among Aboriginal people.

Clinical criteria for the diagnosis of vascular dementia: a multicenter study of comparability and interrater reliability

BACKGROUND

Several clinical criteria have been developed to standardize the diagnosis of vascular dementia (VaD). Significant differences in patient classification have been reported, depending on the criteria used. Few studies have examined interrater reliability.

OBJECTIVE

To assess the concordance in classification and interrater reliability for the following 4 clinical definitions of VaD: the Hachinski Ischemic Score (HIS), the Alzheimer Disease Diagnostic and Treatment Centers (ADDTC), National Institute of Neurological Disorders and Stroke-Association Internationale pour la Recherche et l'Enseignement en Neurosciences (NINDS-AIREN), and Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV).

METHODS

Structured diagnostic checklists were developed for 4 criteria for VaD, 2 criteria for Alzheimer disease (AD), and 4 criteria for dementia. Twenty-five case vignettes, representing a spectrum of cognitive impairment and subtypes of dementia, were prepared in a standardized clinical format. Concordance in case classification using different criteria and interrater reliability among 7 ADDTCs given a specific set of criteria was assessed using the kappa statistic.

RESULTS

The frequency of a diagnosis of VaD was highest using the modified HIS or DSM-IV criteria, intermediate using the original HIS and ADDTC criteria, and lowest using the NINDS-AIREN criteria. Scores for interrater reliability ranged from kappa = 0.30 (ADDTC) to kappa = 0.61 (original HIS).

CONCLUSIONS

Clinical criteria for VaD are not interchangeable. Depending on the criteria selected, the reported prevalence of VaD will vary significantly. The traditional HIS has higher interrater reliability than the newer criteria for VaD. Prospective longitudinal studies with clinical-pathological correlation are needed to compare validity.

Comparing the health status of male and female veterans who use VA health care: results from the VA Women's Health Project

BACKGROUND

In recent years the number of women serving in the military has increased substantially, resulting in more demand for VA services by women veterans. This paper describes the characteristics and health status of women veterans who use VA ambulatory services.

METHODS

Respondents in the VA Women's Health Project (n = 719) represent a randomly selected subsample from all women who had an ambulatory visit between July 1, 1994 and June 30, 1995 at a large tertiary care VA facility in the Boston area. Summary statistics on eight dimensions of health status (using the SF-36) for women veterans who use VA ambulatory care are provided. Comparisons are made between women veterans and men veterans who use VA services.

RESULTS

Women veterans reported consistently low scores on health status across multiple dimensions, reflecting considerable health needs. Among veterans using VA services, women were younger, better educated, and less likely to be married than male veterans. Women veterans who use VA ambulatory services scored lower on every scale except physical functioning and general health perceptions when compared to male VA users. There were more pronounced differences for women on scales measuring emotional health.

CONCLUSIONS

Health status among women veterans is moderate to poor. Important differences in health status are observed between men and women who use VA services which have implications for improving health care to women veterans at VA facilities. These findings strongly indicate that increased mental health services need to be available for women veterans seeking VA health care.

Social support, social selection and self-assessed health status: results from the veterans health study in the United States

This study provided a comprehensive assessment of the association between social support and health using longitudinal data from the Veterans Health Study. Unlike previous studies which examined the relationship between one single domain of social support with either mental or physical health, the present study assessed the effects of three different domains of social support on multiple measures of health. The findings of the study indicated that social support tended to mediate the deleterious effects of non-military traumatic events; whereas the adverse consequences of traumatic events experienced in the military were not affected by social support, suggesting that stressors associated with combat had a long lasting effect on the health status of veterans. The study results revealed that compared with those with better health, respondents with poor health were more likely to have lower levels of social support, suggesting that poor health might be a barrier to a person's ability to participate and/or maintain social relationships. The study also showed that different types of social support had varying beneficial effects on different measures of health. While perceived support had a strong effect on all the measures of health (except alcoholism) included in the study, living arrangement had a significant effect on post-traumatic stress disorder or physical health and participation in group activities had a strong effect only on physical functioning. The results of the study highlight the need for future research to determine whether particular types of social support affect various aspects of health differently. This simultaneous focus on multiple support functions and health outcomes is important because it provides insight into the mechanisms linking social support to health.

Patient satisfaction with Department of Veterans Affairs health care: do women differ from men?

This study compared the patient satisfaction of female and male veterans using Department of Veterans Affairs health care and examined the relationship between sociodemographic characteristics and satisfaction in men and women. Using data from the Department of Veterans Affairs Women's Health Project (N = 719) and the Veterans Health Study (N = 600), we examined women's and men's unadjusted and adjusted mean scores on three dimensions of satisfaction: location of health care facility, access to health care, and prescription services. Although the unadjusted results indicated that women were less satisfied with both location and access, there were no differences in satisfaction with prescription services. After adjusting for age and then for both age and a recent physician visit, women remained less satisfied with location but were more satisfied with prescription services; there were no differences on access ratings. In an exploratory analysis, we examined the relationships between sociodemographic, military experience, and health characteristics and satisfaction within each sample. Older age was the only characteristic consistently positively associated with each dimension of satisfaction among both women and men. General health perceptions were positively associated with all three dimensions of women's satisfaction but with only the location dimension for men. Although other characteristics were associated with satisfaction within each sample, these differed for women and men. The results suggest that although there were not consistent differences in mean satisfaction ratings by gender, the characteristics associated with satisfaction differed for men and women.

Acyl-coenzyme A:cholesteryl acyltransferase 2

In addition to acyl-coenzyme A:cholesterol acyltransferase-1 (ACAT1), an enzyme in the endoplasmic reticulum of cells found ubiquitously throughout the body, data recently obtained in at least three mammalian species, including nonhuman primates, mice and humans, demonstrate the presence of an additional ACAT (EC 2.1.3.26), termed ACAT2, which is localized to the endoplasmic reticulum of liver and intestine. Data suggest that ACAT2 may be the enzyme responsible for cholesteryl ester secretion into apolipoprotein B-containing lipoproteins. We have hypothesized that oversecretion of cholesteryl esters produced by the action of hepatic ACAT2 could account for the increased atherogenicity associated with cholesteryl ester-enriched LDL in nonhuman primates. In such cases, ACAT2 is an appealing target for therapy to reduce coronary heart disease.

Concurrent paclitaxel and radiation therapy for breast cancer

Few studies have evaluated the role of concurrent chemoradiation therapy in the management of locally advanced breast cancer. The availability of radiosensitizing chemotherapeutic agents that are effective in breast cancer and the encouraging results achieved by concurrent chemoradiation in other malignancies have prompted us to investigate this approach. Paclitaxel is a promising agent for use with concurrent radiotherapy because of its single-agent efficacy profile and its radiosensitizing effects. A clinical protocol of preoperative paclitaxel and radiation in locally advanced breast cancer is ongoing at our institution to test feasibility, measure pathologic response at mastectomy, and explore association of pathologic response with molecular tumor markers. Initially, the study was designed to test weekly paclitaxel at a dose of 60 mg/m2 during radiation therapy, delivered 5 days a week at 200 cGy fractions to a total dose of 50 Gy over 5 weeks. Due to severe skin toxicity in the first two patients, the protocol was amended to change the scheduling of paclitaxel to 30 mg/m2 twice weekly and to reduce the radiation to 180 cGy fractions to a total dose of 45 Gy, delivered 5 days a week over 5 weeks. Presently, 13 patients have been accrued; preliminary data indicate good tolerance to twice-weekly paclitaxel, and four of eight evaluable patients have achieved pathologic response (one patient who received the weekly regimen and three who received the twice-weekly regimen). In addition, sequential fine-needle aspirations of palpable breast cancers were obtained in patients enrolled in a parallel study of preoperative single-agent paclitaxel (200 mg/m2 every 2 weeks, for a total of four cycles before breast surgery). Preliminary results suggest that a steep increase in the mitotic index occurs during the first day after paclitaxel administration and plateaus between the second and the third day, then decreases to pretreatment values. The peak apoptotic index occurs at approximately 72 hours after paclitaxel administration and decreases at approximately 98 hours. These initial findings suggest that twice-weekly dosing of paclitaxel may optimize recruitment of cells into the G2/M phase of the cell cycle, the most radiosensitive phase.

Neurons in the dorsal column white matter of the spinal cord: complex neuropil in an unexpected location

It is common to think of gray matter as the site of integration in neural circuits and white matter as the wires that connect different groups of neurons. The dorsal column (DC) white matter, for example, is the spinal cord axonal pathway through which a topographic map of the body is conveyed to the somatosensory cortex. We now describe a network of neurons located along the midline of the DCs. The neurons are present in several mammals, including primates and birds, and have a profuse dendritic arbor that expresses both the neuron-specific marker, microtubule-associated protein-2, and the neurokinin-1 receptor, a target of the neuropeptide, substance P. Electron microscopy and double immunostaining for synaptophysin and a marker of gamma-aminobutyric acid-ergic terminals documented a rich synaptic input to these neurons. Finally, injection of a gamma-aminobutyric acid type A receptor antagonist or of substance P into the cerebrospinal fluid of the rat spinal cord induced Fos expression and internalization of the neurokinin-1 receptor in these neurons, respectively, indicating that the DC neurons are under tonic inhibitory control and can respond to neurotransmitters that circulate in the cerebrospinal fluid.

Health status in VA patients: results from the Veterans Health Study

Recently, the Veterans Administration (VA) Under Secretary for Health has designated functional status as one of the domains of value for the system, given its increasing importance for clinical care. The Veterans Health Study (VHS) was designed to assist the VA in monitoring outcomes and measuring the case mix of patients who use the VA. The Veterans SF-36 (short form functional status assessment for veterans) was administered to 2425 veterans receiving ambulatory care. Measures of the Veterans SF-36 were strongly correlated with sociodemographics and morbidities of the veterans. Young veterans had poorer mental health status than older veterans. Veterans who used ambulatory care in the VHS reported lower levels of health status, reflecting more disease than a non-VA civilian population. These measures of health are important indicators of the disease burden or case mix of the patients and are pertinent to health systems such as the VA for resource allocation decisions and as outcomes of care.

The cloned capsaicin receptor integrates multiple pain-producing stimuli

Capsaicin, the main pungent ingredient in "hot" chili peppers, elicits buming pain by activating specific (vanilloid) receptors on sensory nerve endings. The cloned vanilloid receptor (VR1) is a cation channel that is also activated by noxious heat. Here, analysis of heat-evoked single channel currents in excised membrane patches suggests that heat gates VR1 directly. We also show that protons decrease the temperature threshold for VR1 activation such that even moderately acidic conditions (pH < or = 5.9) activate VR1 at room temperature. VR1 can therefore be viewed as a molecular integrator of chemical and physical stimuli that elicit pain. Immunocytochemical analysis indicates that the receptor is located in a neurochemically heterogeneous population of small diameter primary afferent fibers. A role for VR1 in injury-induced hypersensitivity at the level of the sensory neuron is presented.

Health-related quality of life in patients served by the Department of Veterans Affairs: results from the Veterans Health Study

BACKGROUND

The Department of Veterans Affairs Health Care System (VA) is the largest integrated single payer system in the United States. To date, there has been no systematic measurement of health status in the VA. The Veterans Health Study has developed methods to assess patient-based health status in ambulatory populations.

OBJECTIVES

To describe the health status of veterans and examine the relationships between their health-related quality of life, age, comorbidity, and socioeconomic and service-connected disability status.

METHODS

Participants in the Veterans Health Study, a 2-year longitudinal study, were recruited from a representative sample of patients receiving ambulatory care at 4 VA facilities in the New England region. The Veterans Health Study patients received questionnaires of health status, including the Medical Outcomes Study Short Form 36-Item Health Survey; and a health examination, clinical assessments, and medical history taking. Sixteen hundred sixty-seven patients for whom we conducted baseline assessments are described.

RESULTS

The VA outpatients had poor health status scores across all measures of the Medical Outcomes Study Short Form 36-Item Health Survey compared with scores in non-VA populations (at least 50% of 1 SD worse). Striking differences also were found with the sample stratified by age group (20-49 years, 50-64 years, and 65-90 years). For 7 of the 8 scales (role limitations due to physical problems, bodily pain, general health perceptions, vitality, social functioning, role limitations due to emotional problems, and mental health), scores were considerably lower among the younger patients; for the eighth scale (physical function), scores of the young veterans (aged 20-49 years) were almost comparable with the levels in the old veterans (>65 years). The mental health scores of young veterans were substantially worse than all other age groups (P<.001) and scores of screening measures for depression were significantly higher in the youngest age group (51%) compared with the oldest age groups (33% and 16%) (P<.001).

CONCLUSIONS

The VA outpatients have substantially worse health status than non-VA populations. Mental health differences between the young and old veterans who use the VA health care system are sharply contrasting; the young veterans are sicker, suggesting substantially higher resource needs. Mental health differences may explain much of the worse health-related quality of life in young veterans. As health care systems continue to undergo a radical transformation, the Department of Veterans Affairs should focus on the provision of mental health services for its younger veteran.

Comparing generic and disease-specific measures of physical and role functioning: results from the Veterans Health Study

OBJECTIVES

This study compared the performance of generic measures of Medical Outcome Study Short Form 36-Item Health Survey physical functioning and role limitations with disease-specific measures of physical functioning and role limitations using specific disease attributions for chronic lung disease, chronic low back pain, and osteoarthritis of the knee.

METHODS

Data were analyzed from the Veterans Health Study among patients receiving Veteran's Administration ambulatory care. Patients identified as having one of the three study conditions were included in the study (n = 932).

RESULTS

The study revealed that the generic physical functioning and role limitations scales had higher correlations with other generic SF-36 scales, whereas disease-specific attribution measures had larger R2 values in explaining variability in symptom-based disease severity and larger t statistic values in discriminating the impacts of patients taking medications and having surgery.

CONCLUSIONS

The generic measures of physical functioning and role limitations were more applicable in assessing a broad array of health-related quality-of-life issues, whereas disease-specific measures of physical functioning and role limitations were more useful in evaluating clinical management and limitations associated with specific disease conditions. The results of the study suggest that the use of disease-specific attribution assessments was more cost-efficient than the development of new disease-specific instruments. Disease-specific attribution could be used to complement generic measures in assessing patient outcomes.

Cholecystokinin and enkephalin in brain stem pain modulating circuits

Neurons in rostral ventromedial medulla and the periaqueductal gray modulate dorsal horn nociceptive transmission. Endogenous peptides implicated in this modulation include enkephalin (ENK), which is antinociceptive, and cholecystokinin (CCK), which has anti-opioid effects. In this study double-label fluorescence immunocytochemistry demonstrated somata and terminals with ENK- or CCK-like immunoreactivity in these regions. Although the distribution of CCK- and ENK-immunoreactive terminal fields overlapped significantly, co-localization was rare. Furthermore, CCK- and ENK-immunoreactive somata had different morphologies and distinct distributions. The overlap of CCK- and ENK- immunoreactive terminals arbors provides a morphological substrate for an antagonistic interaction of CCK and ENK within brainstem pain modulating circuits, as has been demonstrated in the spinal cord.

GABA-immunoreactive boutons contact identified OFF and ON cells in the nucleus raphe magnus

The pontomedullary raphe magnus (RM) contains two physiologically defined types of neurons that participate in the opioid-induced modulation of dorsal horn nociceptive messages: OFF cells, which decrease, and ON cells, which increase their discharge rates when reflex behavior is evoked by noxious pinch or heat. Because both types of neuron have inhibitory inputs and because there is evidence that gamma-aminobutyric acid (GABA) inhibitory mechanisms within RM contribute to the antinociceptive action of opioids, we have sought anatomical evidence for a direct GABAergic input to OFF and ON cells. In this study, cells of each type located in the RM were electrophysiologically defined and intracellularly filled with horseradish peroxidase or Neurobiotin. One cell of each type was labeled in the cat, and 2-3 cells of each type were labeled in the rat. Thin sections were labeled by a postembedding immunogold procedure by using an antibody directed against glutaraldehyde-conjugated GABA. GABA-immunoreactive (GABA-ir) boutons contained small, round, clear vesicles and made symmetrical synapses with identified dendrites. GABA-ir boutons were apposed to soma and to proximal and distal dendrites of both cell types in both species. These findings demonstrate direct GABAergic input to identified OFF and ON cells in the RM. J. Comp. Neurol. 378:196-204, 1997.

Noradrenergic input to nociceptive modulatory neurons in the rat rostral ventromedial medulla

Within the rostral ventromedial medulla (RVM), there are two classes of putative pain modulation neurons: ON cells and OFF cells, which respectively burst or pause prior to withdrawal reflexes elicited by noxious stimulation. Alpha-adrenergic agonists injected into the RVM produce changes in the latency of spinal nocifensive reflexes and, when iontophoretically applied, alter the firing of RVM ON but not OFF cells. To provide further information about the contribution of norepinephrine to RVM neuron function, we analyzed the distribution of tyrosine hydroxylase immunoreactive (TH-ir) appositions upon RVM ON and OFF cells. In the lightly anesthetized rat, seven ON and five OFF cells were identified by changes in their discharge rate in relation to nociceptive withdrawal reflexes and were labeled by intracellular injection of neurobiotin. Sections containing labeled cells were visualized by using avidin conjugated to a Texas Red fluorophore. Tissue with labeled cells was subsequently processed for TH-ir by using a Bodipy fluorophore conjugated secondary antibody. The distribution of the Bodipy-labeled fibers and terminals upon the Texas Red-labeled neurons was mapped using a confocal laser-scanning microscope. All the labeled neurons exhibited close TH-ir appositions. Appositions were of two types: swellings and fibers. Although the numbers and density of appositions varied among the cells, there were no consistent differences that correlated with physiological properties. Thus the overall density of appositions for ON cells (29.0 +/- 22.2 x 10(4) microns2) did not differ significantly from that for OFF cells (25.4 +/- 22.2 x 10(4) microns2). Tyrosine hydroxylase immunoreactive (TH-ir) appositions upon ON and OFF cells varied with their location along the dorso-ventral axis with more ventral neurons having a greater density of TH-ir swelling-type appositions. In a separate study, TH-ir and dopamine-beta-hydroxylase-like immunoreactivity (DBH-ir) were mapped in the same sections by using confocal microscopy. Nearly 97% of the TH-ir profiles co-localized with DBH-ir. These observations provide evidence that both ON and OFF cells in the RVM are targeted by noradrenergic inputs.

A hyaluronate based gel for the prevention of postsurgical adhesions: evaluation in two animal species

OBJECTIVE

To assess in two animal surgery models, the efficacy of a bioabsorbable gel to prevent postoperative adhesions.

DESIGN

A randomized, prospective, blinded study using animal abdominal surgery models.

SETTING

Two animals species with surgical traumas to induce adhesion formation.

INTERVENTIONS

A chemically modified hyaluronate and carboxymethylcellulose-based gel formulation.

MAIN OUTCOME MEASURES

The number of animals with no adhesions, mean number of adhesions, and total adhesion score.

RESULTS

Treatment with the bioabsorbable gel increased the number of animals without any adhesion by 70% in a rat cecal abrasion model and by > 90% in a rabbit sidewall defect-bowel abrasion model when compared with nontreatment control animals. Other outcome measures showed similar efficacy.

CONCLUSION

The modified hyaluronate-carboxymethylcellulose gel was effective in two animal species after surgery in the abdominal cavity. The gel appears to act as a physical barrier between damaged peritoneal tissue and may be appropriate for human clinical trials in open and laparoscopic surgical procedures.

Adhesion formation after laparoscopic anterior resection in a porcine model: a pilot study

Although decreased adhesion formation is one of the accepted advantages of laparoscopic colorectal surgery, no prospective studies have been done to support this claim. Therefore, we prospectively assessed adhesion formation following laparoscopic anterior resection of the rectum in a porcine model. Five domestic female pigs underwent the procedure with a double-stapled intracorporeal anastomosis. After completion of the laparoscopic procedure, 50 cm of ileum was retrieved through the right lower port site. Controlled serosal abrasion of the antimesenteric surface was performed using a fresh knife. The abraded loop was returned into the peritoneal cavity and the fascia closed at all port sites. All animals underwent a midline laparotomy 3 weeks later to assess adhesions using a 0-3 score according to the density vascularity, and extent of adhesions. All animals survived the study period. The mean level of the anastomosis was 8 cm (range, 7-10) above the anal verge; all anastomoses were intact and completely healed. None of the animals had adhesions to the port sites. The anastomotic site was completely free of adhesions in four animals, and only one animal (20%) had grade 1 adhesions between the urine horns and the anastomosis. Conversely, all animals had adhesions of the abraded loop involving 60 cm (range, 40-75) of bowel and 7 cm (range, 4-9) of the abdominal wall (remote to the port sites); no other adhesions were noted. In this pilot study, serosal abrasion of the small bowel resulted in severe adhesion formation in the porcine model. However, laparoscopic anterior resection of the rectum in the same animals was associated with only minimal insignificant adhesions. Furthermore, unlike in laparotomy incisions, adhesions to port sites did not occur.

Maternal infusion of antioxidants (Trolox and ascorbic acid) protects the fetal heart in rabbit fetal hypoxia

The antioxidants, Trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid, a water soluble analog of vitamin E) and ascorbic acid (AA), protect the heart from ischemia-reperfusion injury. We hypothesized that maternal infusion of Trolox and AA, would reduce the fetal bradycardia and myocardial damage observed in fetal hypoxia and increase the total antioxidant activity in fetal plasma. Either i.v. saline (control group) or Trolox + AA (drug group) was randomly administered to 29-d-old pregnant rabbits. Fetal hypoxia was induced by uterine ischemia. Fetal heart rate, plasma CK-MB activity, and plasma total radical antioxidant potential (TRAP) were measured in different sets of animals. Fetal heart rate in the drug group was higher than in the control group for the first 35 min (p < 0.05 at every 5-min interval). Fetal bradycardia (<60 beats/min) occurred after 39 min (median) in the drug group, and 29 min in the control group (p < 0.05). After 50 min of hypoxia, plasma CK-MB was lower in the drug group, 1204 +/- 132 U/L (mean +/- SEM), than in the control group, 2633 +/- 233 U/L (p < 0.05). TRAP was higher in the drug group, 3.01 +/- 0.15 mM (Trolox equivalent concentration), than in the control group, 1.48 +/- 0.27 mM (p < 0.05). Higher TRAP levels (> or = 2.0 mM) were associated with lower CK-MB levels (<2500 U/L) (p < 0.05). Administration of Trolox and AA to the mother has a beneficial effect on fetal myocardial damage after fetal hypoxia, and a small beneficial effect on fetal bradycardia during hypoxia. The beneficial effect may be due to the augmentation of fetal plasma antioxidants from maternal antioxidant pretreatment.

Prevention of tissue injury and postsurgical adhesions by precoating tissues with hyaluronic acid solutions

The effectiveness of inhibiting serosal tissue damage and preventing surgical adhesions by precoating tissues with dilute solutions of hyaluronic acid (HA) was evaluated in a rat cecal abrasion model. This study was performed at three independent laboratories using the same protocol. Three hundred and seventy-five adult rats were divided into five treatment groups (125 animals at each study site): 0.1% HA, 0.25% HA, 0.4% HA, phosphate-buffered saline solution (PBS), and no solution. The abdominal cavity of each animal was precoated with 4 ml of test solution or no solution, prior to a controlled abrasion of the cecum. One week later, the animals were sacrificed and adhesions were scored on a 0-4 scale. The data were pooled because no statistical difference was found in the trends at the three study sites. The PBS precoating and no tissue precoating treatment groups had the same high incidence of cecal adhesions, which was significantly higher than the incidence of adhesions in the HA treatment groups. As the HA concentration in the precoating solution increased from 0% (PBS group) to 0.4% HA, the mean incidence of cecal adhesions decreased in a concentration-dependent manner from 1.6 +/- 0.11 to 0.7 +/- 0.09 (P < 0.001). The percentage of animals with no cecal adhesions increased from 11% in the PBS group to 50% in the 0.4% HA treatment group (P < 0.001). In a separate histological study employing 150 rats, HA solutions significantly inhibited serosal tissue damage and ameliorated the inflammatory response due to abrasion and desiccation compared to that with no coating or precoating with buffered saline. Together, these studies demonstrate that tissue precoating with dilute HA solutions reduces damage to serosal tissues during surgery and thereby limits formation of postsurgical adhesions.