A comparison of two stretching protocols on hip range of motion: implications for total daily stretch duration

It is theorized that the total stretch time in a day is more important than the actual single stretch duration time. The purpose of this study was to compare 2 stretching protocols, keeping total stretching time equivalent. The 2 protocols were a 10-second duration stretch and a 30-second duration stretch. Although the stretch durations differed, the total stretching time over the course of a day was held constant at 2 minutes for both protocols. Participants were randomly assigned a protocol to each of their legs: subjects stretched 1 leg with the 10-second protocol and the opposite leg with the 30-second protocol. The 10-second stretch was repeated 6 times for a total of 1 minute; the 30-second protocol was repeated 2 times for a total of 1 minute. Stretching was performed twice daily (a total of 2 minutes each day) for 6 weeks. All stretching was performed to the hamstring muscles. Hip flexion measurements were recorded at pretest, 3-weeks, and 6-weeks. Subjects demonstrated significant gains in range of motion for hip flexion over the course of 6 weeks, p = 0.000. No differences existed between the 2 protocols. Range of motion gains were equal between the 2 stretching protocols. The common denominator was total stretch time for a day. Regardless of the duration of a single stretch, the key to improvement was the total daily stretch time. These findings are important as they allow clinicians and individuals to customize stretching protocols to meet individual needs.     

A validated LC/MS/MS method for the quantification of pyrrole-2,3,5-tricarboxylic acid (PTCA), a eumelanin specific biomarker, in human skin punch biopsies

A novel skin tissue extraction method coupled with liquid chromatography-tandem mass spectrometry (LC/MS/MS) detection was developed and validated for the analysis of endogenous pyrrole-2,3,5-tricarboxylic acid (PTCA), a eumelanin specific biomarker, in human skin punch biopsies. The analyte is extracted from the matrix (2 mm skin punch biopsies) using a simple oxidative degradation procedure. The extract supernatants are evaporated, reconstituted in mobile phase solvent, and injected into the LC/MS/MS system without further derivatization. The chromatographic separation is achieved on a reverse phase high performance liquid chromatography (HPLC) column. The accuracy and precision of the method was determined over the concentration range of 1-1000 ng/mL PTCA from human skin extracts in three validation batch runs. Inter-assay precision (%CV) and accuracy (%R.E.) of the quality control samples were 相似文献   

A reverse genetic, nontransgenic approach to wheat crop improvement by TILLING

We report the use of TILLING (targeting induced local lesions in genomes), a reverse genetic, nontransgenic method, to improve a quality trait in a polyploid crop plant. Waxy starches, composed mostly of amylopectin, have unique physiochemical properties. Wheat with only one or two functional waxy genes (granule-bound starch synthase I, or GBSSI) produces starch with intermediate levels of amylopectin. We have identified 246 alleles of the waxy genes by TILLING each homoeolog in 1,920 allohexaploid and allotetraploid wheat individuals. These alleles encode waxy enzymes ranging in activity from near wild type to null, and they represent more genetic diversity than had been described in the preceding 25 years. A line of bread wheat containing homozygous mutations in two waxy homoeologs created through TILLING and a preexisting deletion of the third waxy homoeolog displays a near-null waxy phenotype. This approach to creating and identifying genetic variation shows potential as a tool for crop improvement.     

A comparison of lower-body flexibility, strength, and knee stability between karate athletes and active controls

The purposes of this study were to compare the lower-body flexibility, strength, and knee stability of karate athletes against that of non-karate controls and to determine whether regular karate training results in adaptations that may result in an increased risk for knee injury. Flexibility measurements included knee flexion and extension, hip flexion and extension, hip internal and external rotation, and foot inversion and eversion. Nine karate athletes (4 women and 5 men, age = 24.3 +/- 6.7 years) and 15 active, non-karate controls (7 women and 8 men, age = 22.1 +/- 3.2 years) participated. No subjects reported recent knee surgery or chronic or acute knee pain. Concentric quadriceps and hamstrings strength and endurance were measured using a Biodex II isokinetic dynamometer at 60 degrees .s(-1) and 180 degrees .s(-1). Eccentric strength was measured at 150 degrees .s(-1) and 250 ft-lb (339 N.m). Knee stability was measured via varus and valgus stress and anterior drawer testing. Karate athletes demonstrated a significantly greater right hip flexion (p 相似文献   

Nutrient composition of selected whole invertebrates

Although nutrient requirements of insectivores have not been specifically determined, detailed chemical analysis of invertebrates used in zoo feeding programs is essential for evaluating nutritional adequacy based on domestic animal models. Additionally, such data can provide valuable suggestions for future research priorities. Proximate composition, fat-soluble vitamins, and minerals in mealworms (Tenebrio molitor and Zophobas morio), crickets (Acheta domesticus), waxworms (Galleria mellonella), fruit flies (Drosophila melanogaster), and earthworms (Lumbricus terrestris) were determined. All species had a water content >50% of their body weights. Larval invertebrates had higher fat content (x >30% dry matter [DM]) than adult species. Total nitrogen (N) ranged from 5.2±1.1% DM (earthworms) to 10.3±0.4% DM (adult crickets), whereas chemically bound N comprised 3–10% of total N in all invertebrates. Neutral detergent fiber, used as a measure of chitin, averaged 15.3±3.6% DM for all species except wild-caught earthworms, which were higher (51% DM). Vitamin E concentrations ranged from 15±3 IU/kg DM (mealworms) to 509±232 IU/kg DM (waxworms). Vitamin A concentrations were undetectable (fruit flies) to low in all samples; none met the recommended dietary vitamin A concentrations established for domestic carnivores. Insects had low calcium concentrations (x = 0.11%) and imbalanced calcium:phosphorus ratios except for pinhead crickets. Insects sampled contained sufficient concentrations of Cu, Fe, Mg, P, and Zn to meet known requirements of domestic birds and mammals, whereas supermealworms and waxworms contained deficient levels of Mn. Earthworms appeared to meet dietary mineral requirements, based on domestic bird and mammal recommendations. Zoo Biol 17:123–134, 1998. © 1998 Wiley-Liss, Inc.     

Occurrence of Antimicrobial-Resistant Escherichia coli and Salmonella enterica in the Beef Cattle Production and Processing Continuum

Specific concerns have been raised that third-generation cephalosporin-resistant (3GC^r) Escherichia coli, trimethoprim-sulfamethoxazole-resistant (COT^r) E. coli, 3GC^r Salmonella enterica, and nalidixic acid-resistant (NAL^r) S. enterica may be present in cattle production environments, persist through beef processing, and contaminate final products. The prevalences and concentrations of these organisms were determined in feces and hides (at feedlot and processing plant), pre-evisceration carcasses, and final carcasses from three lots of fed cattle (n = 184). The prevalences and concentrations were further determined for strip loins from 103 of the carcasses. 3GC^r Salmonella was detected on 7.6% of hides during processing and was not detected on the final carcasses or strip loins. NAL^r S. enterica was detected on only one hide. 3GC^r E. coli and COT^r E. coli were detected on 100.0% of hides during processing. Concentrations of 3GC^r E. coli and COT^r E. coli on hides were correlated with pre-evisceration carcass contamination. 3GC^r E. coli and COT^r E. coli were each detected on only 0.5% of final carcasses and were not detected on strip loins. Five hundred and 42 isolates were screened for extraintestinal pathogenic E. coli (ExPEC) virulence-associated markers. Only two COT^r E. coli isolates from hides were ExPEC, indicating that fed cattle products are not a significant source of ExPEC causing human urinary tract infections. The very low prevalences of these organisms on final carcasses and their absence on strip loins demonstrate that current sanitary dressing procedures and processing interventions are effective against antimicrobial-resistant bacteria.     

Practical Considerations When Using Temperature to Obtain Rate Constants and Activation Thermodynamics of Enzymes with Two Catalytic Steps: Native and N460T-β-Galactosidase (<Emphasis Type="Italic">E. coli</Emphasis>) as Examples

The values of the rate constants and the associated enthalpies and entropies of enzymes with two catalytic steps can be measured by determining the effects of temperature on the k _cat values. Practical considerations that should be taken into account when doing this are presented. The narrow temperature range available with enzymes and the sensitivity of pH to temperature mean that special attention to detail must be taken and this study highlights the assiduousness needed. The necessity of conversion of apparent k _cat to true k _cat values when assays are done with products having pKa values near to the assay pH is shown and the importance of obtaining sufficient data is emphasized. Reasons that non-linear regression should be used to obtain the estimates of rate constants and activation thermodynamic parameters are given. Other precautions and recommendations are also presented. Results obtained by this method for native β-galactosidase (E. coli) and for a β-galactosidase in which a Thr was substituted for Asn-460 were analyzed to demonstrate the valuable mechanistic details of enzymes that can be obtained from studies of this type.

Salmonella and Escherichia coli O157:H7 Contamination on Hides and Carcasses of Cull Cattle Presented for Slaughter in the United States: an Evaluation of Prevalence and Bacterial Loads by Immunomagnetic Separation and Direct Plating Methods

The hide and carcass hygiene of cull cattle at slaughter in four geographically distant regions of the United States was examined from July 2005 to April 2006 by measuring the aerobic plate counts (APC) and the prevalences and loads of Salmonella and Escherichia coli O157:H7. The geometric mean log₁₀ APC CFU/100 cm² levels on hides and preevisceration and postintervention carcasses ranged from 6.17 to 8.19, 4.24 to 6.47, and 1.46 to 1.96, respectively, and were highest in the summer (P < 0.0001). The average prevalences of Salmonella on hides and preevisceration and postintervention carcasses were 89.6% (95% confidence interval [CI], 85.1 to 94.0), 50.2% (95% CI, 40.9 to 59.5), and 0.8% (95% CI, 0.18 to 1.42), respectively. The prevalences of E. coli O157:H7 were 46.9% (95% CI, 37.3 to 56.6) and 16.7% (95% CI, 9.8 to 23.6) on hides and preevisceration carcasses, respectively. Examination of the concomitant incidence of Salmonella and E. coli O157:H7 showed that, on average, 33.3% (95% CI, 15.9 to 69.8) of cattle hide and 4.1% (95% CI, 0.98 to 17.3) of preevisceration carcass samples were contaminated with both pathogens. The pathogen prevalence on hides and carcasses was not significantly affected by the season; however, significant differences were observed between plants with respect to the incoming pathogen load and the ability to mitigate hide-to-carcass transfer. In spite of these differences, postintervention carcass contamination was significantly reduced (P < 0.001), likely as a result of the use of one or more of the processing interventions employed at each of the four processing plants examined.     

Inflammatory bowel disease requires the interplay between innate and adaptive immune signals

Inflammatory bowl disease （IBD） is a type 1 T helper cell （Th1）-mediated autoimmune disease. Various studies have revealed that environmental pathogens also play a significant role in the initiation and progression of this disease. Interestingly, the pathogenesis of IBD has been shown to be related to nitric oxide （NO） released from innate immune cells. Although NO is known to be highly toxic to the gut epithelia, there is very little information about the regulation of NO production, One major question in the etiology of IBD is how Thl cells and pathogens interact in the induction of IBD. In present study, we focused on the regulation of NO. We show that macrophages require both interferon-γ, （IFN-γ）-mediated and TLR4-mediated signals for the production of NO, which causes inflammation in the intestine and subsequently IBD. Thus, IBD is the result of concerted actions of innate immune signals, such as the binding of LPS to TLR-4, and adaptive immune signals, such as IFN-γ produced by Thl cells.     

Comparative analysis of aryl-hydrocarbon receptor interacting protein-like 1 (Aipl1), a gene associated with inherited retinal disease in humans

Mutations in AIPL1 cause Leber congenital amaurosis (LCA), the most severe form of inherited blindness in children; however, the function of this protein in normal vision remains unknown. To determine amino acid subsequences likely to be important for function, we have compared the protein sequence of several species. Sequence conservation is highest across the three Aipl1 tetratricopeptide (TPR) motifs and extends across the protein, except for a proline-rich amino acid sequence present only at the C-terminus of primate Aipl1. The length of the proline-rich region varies within primates; however, the length differences between human and primate Aipl1 do not correlate with evolutionary distance. These observations reinforce the importance of the TPR domains for function, the similarity of Aipl1 to a family of proteins that act as molecular chaperones, and the importance of comparative sequencing data for determination of whether AIPL1 sequence variants in patients are likely to cause retinopathy. Received: 8 December 2000 / Accepted: 5 March 2001