The Constipation Severity Instrument: A Validated Measure

Purpose This study was designed to develop and test the validity and reliability of the Constipation Severity Instrument. Methods Scale development was conducted in two stages: 1) 74 items were generated through a literature review and focus groups of constipated patients and medical providers; and 2) a preliminary instrument was administered to 191 constipated patients and 103 healthy volunteers. Test-retest reliability of the constipated group was assessed (N = 90). Content, convergent, divergent, and discriminant validity were evaluated by using other validated measures by performing one-way analysis of variance and Pearson correlations. Results Exploratory and confirmatory factor analysis revealed three subscales: obstructive defecation, colonic inertia, and pain. Internal consistency (α = 0.88–0.91) and test-retest reliability (intraclass correlation coefficients = 0.84–0.91) were high for all subscales. Constipated patients were grouped by Rome II criteria: functional constipation (22 percent), pelvic floor dyssynergia (15 percent), constipation predominant irritable bowel syndrome (23 percent), and no specific criteria (40 percent). Those with constipation predominant irritable bowel syndrome or pelvic floor dyssynergia scored higher on the Obstructive Defecation and Colonic Inertia subscales than those with functional constipation or no specific criteria (P = 0.001–0.058). Subjects with functional constipation had much lower scores on the pain subscale than constipation predominant irritable bowel syndrome, functional constipation, or no specific criteria (P < 0.009).The Constipation Severity Instrument subscale and total score correlated very highly with the subscales and total score of the Patient Assessment of Constipation Symptom measure. The Constipation Severity Instrument subscales discriminated well between constipated patients and healthy volunteers (P < 0.001) and demonstrated excellent divergent validity. Higher Constipation Severity Instrument scores inversely correlated with general quality of life. Conclusions The Constipation Severity Instrument is a reliable and valid instrument for assessing constipated patients. Administration of the Constipation Severity Instrument to other constipated patients will further validate its use. Supported by the University of California San Francisco Hellman Family Award for Early Career Faculty. Read at the meeting of The American Society of Colon and Rectal Surgeons, St. Louis, Missouri, June 2 to 6, 2007. Reprints are not available.     

Contributions to enhanced activity in rectus femoris in response to Lokomat-applied resistance

The application of resistance during the swing phase of locomotion is a viable approach to enhance activity in the rectus femoris (RF) in patients with neurological damage. Increased muscle activity is also accompanied by changes in joint angle and stride frequency, consequently influencing joint angular velocity, making it difficult to attribute neuromuscular changes in RF to resistance. Thus, the purpose of this study was to evaluate the effects of resistance on RF activity while constraining joint trajectories. Participants walked in three resistance conditions; 0 % (no resistance), 5 and 10 % of their maximum voluntary contraction (MVC). Visual and auditory biofeedback was provided to help participants maintain the same knee joint angle and stride frequency as during baseline walking. Lower limb joint trajectories and RF activity were recorded. Increasing the resistance, while keeping joint trajectories constant with biofeedback, independently enhanced swing phase RF activity. Therefore, the observed effects in RF are related to resistance, independent of any changes in joint angle. Considering resistance also affects stride frequency, a second experiment was conducted to evaluate the independent effects of resistance and stride frequency on RF activity. Participants walked in four combinations of resistance at 0 and 10 %MVC and natural and slow stride frequency conditions. We observed significant increases in RF activity with increased resistance and decreased stride frequency, confirming the independent contribution of resistance on RF activity as well as the independent effect of stride frequency. Resistance and stride frequency may be key parameters in gait rehabilitation strategies where either of these may be manipulated to enhance swing phase flexor muscle activity in order to maximize rehabilitation outcomes.     

Differences in male–female ratios of Aedes albopictus (Diptera: Culicidae) following ultra-low volume adulticide applications

Suppression of Aedes albopictus populations is a substantial challenge for mosquito control programs globally because juveniles of this species are found in numerous kinds of domestic artificial containers that are difficult to detect, access, and eliminate. We conducted a multi-year assessment of the effect of different interventions to control Ae. albopictus near the northernmost geographic boundary of the species in temperate North America and deployed an array of BG-Sentinel traps for adult surveillance. Here we present the results of a comparative examination of adult sex ratios in urban and suburban areas, shifts in sex ratios after control interventions, and a discussion of the critical drivers of population dynamics of Ae. albopictus in our area. We collected significantly more male mosquitoes in urban as compared to suburban areas in June through September, but not in May (p < 0.001). The higher number of male mosquitoes in urban areas could be attributed to a higher number of larval habitats within a closer proximity of the surveillance traps and the lower flight dispersal of males. Following application of adulticides in urban areas, Ae. albopictus male populations were reduced by 88% on average, which was higher than the 69% reduction in female populations. The higher reduction of male mosquitoes could be attributed to the smaller body mass of the males and their higher susceptibility to adulticides. The results of this study are directly relevant to the development of suitable control strategies that depend on manipulation of males, such as the sterile insect technique. The results could also be used to refine mosquito abatement by providing more accurate methods to determine the need and timing of vector control.     

Serosurveillance of eastern equine encephalitis virus in amphibians and reptiles from Alabama, USA

Eastern equine encephalitis virus (EEEV) is among the most medically important arboviruses in North America, and studies suggest a role for amphibians and reptiles in its transmission cycle. Serum samples collected from 351 amphibians and reptiles (27 species) from Alabama, USA, were tested for the presence of antibodies against EEEV. Frogs, turtles, and lizards showed little or no seropositivity, and snakes had high seropositivity rates. Most seropositive species were preferred or abundant hosts of Culex spp. mosquitoes at Tuskegee National Forest, that target ectothermic hosts. The cottonmouth, the most abundant ectotherm sampled, displayed a high prevalence of seropositivity, indicating its possible role as an amplification and/or over-wintering reservoir for EEEV.     

Drug resistance and coreceptor usage in HIV type 1 subtype C-infected children initiating or failing highly active antiretroviral therapy in South Africa

HIV-1 drug resistance monitoring in resource-poor settings is crucial due to limited drug alternatives. Recent reports of the increased prevalence of CXCR4 usage in subtype C infections may have implications for CCR5 antagonists in therapy. We investigated the prevalence of drug resistance mutations and CXCR4 coreceptor utilization of viruses from HIV-1 subtype C-infected children. Fifty-one children with virological failure during highly active antiretroviral therapy (HAART) and 43 HAART-naive children were recruited. Drug resistance genotyping and coreceptor utilization assessment by phenotypic and genotypic methods were performed. At least one significant drug resistance mutation was present in 85.4% of HAART-failing children. Thymidine analogue mutations (TAMs) were detected in 58.5% of HAART-failing children and 39.0% had ≥3 TAMs. CXCR4 (X4) or dual (R5X4)/mixed (R5, X4) (D/M)-tropic viruses were found in 54.3% of HAART-failing and 9.4% of HAART-naive children (p<0.0001); however, the HAART-failing children were significantly older (p<0.0001). In multivariate logistic regression, significant predictors of CXCR4 usage included antiretroviral treatment, older age, and lower percent CD4(+) T cell counts. The majority of genotypic prediction tools had low sensitivity (≤65.0%) and high specificity (≥87.5%) for predicting CXCR4 usage. Extensive drug resistance, including the high percentage of TAMs found, may compromise future drug choices for children, highlighting the need for improved treatment monitoring and adherence counseling. Additionally, the increased prevalence of X4/D/M viruses in HAART-failing children suggests limited use of CCR5 antagonists in salvage therapy. Enhanced genotypic prediction tools are needed as current tools are not sensitive enough for predicting CXCR4 usage.     

Characterization of proteoglycan 4 and hyaluronan composition and lubrication function of ovine synovial fluid following knee surgery

The objective of this study was to determine changes in (1) proteoglycan 4 (PRG4) and hyaluronan (HA) concentration, (2) HA molecular weight (MW) distribution, and (3) cartilage boundary lubricating ability of synovial fluid (SF) from surgical sham (SHAM), anterior cruciate ligament (ACL)/medial collateral ligament (MCL) transection, and lateral meniscectomy (MEN) in a post‐knee surgery ovine model. Ovine SF (oSF) was collected at euthanization 20 weeks after surgery, with the contralateral joint serving as the non‐operative control. PRG4 and HA concentration in oSF was measured by sandwich enzyme‐linked immunosorbent assay, and HA MW distribution by agarose gel electrophoresis. Cartilage boundary lubricating ability of oSF was measured by a cartilage–cartilage friction test. PRG4 and HA concentration in SHAM, ACL/MCL, and MEN oSF were similar in comparison to the contralateral control (CTRL) oSF. The HA MW distribution in the operated oSF for all ranges were similar to the respective CTRL oSF. The kinetic coefficients of friction in operated and CTRL oSF were similar in all groups, and were significantly lower than saline. These results indicate oSF lubricant composition and function at 20 weeks post‐knee surgery were similar to contralateral CTRL, and suggest earlier time points post surgery warrant further investigation. © 2013 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 31:1549–1554, 2013