Loaded Inter-set Stretching for Muscular Adaptations in Trained Males: Is the Hype Real?

The study examined the effects of adding a loaded stretch in the inter-set rest period (ISS) compared to traditional resistance training (TR) on muscular adaptations in resistance-trained males. Twenty-six subjects were randomly assigned into two groups (ISS: n=12; TR: n=14) and underwent an 8-week training regimen. Subjects in ISS underwent an additional loaded stretch for 30 s at 15% of their working load from the prior set during the inter-set rest periods. Muscle thickness of the pectoralis major at the belly (BMT) and lateral (LMT) portions, One-repetition maximum (1RM) and repetitions-to-failure (RTF) on the bench press exercise were measured at baseline and post 8 weeks of training. Additionally, volume load and perceptual parameters for exertion and recovery were measured. Both groups had similar total volume load and average perceptual parameters (p>0.05). There was a main time effect (p<0.01) for all but one dependent variable indicating that both groups responded similarly across time [(∆BMT: ISS=2.7±1.7 mm; TR = 3.0±2.2 mm), (∆LMT: ISS=3.2±1.6 mm; TR=2.8±1.7 mm, (∆1RM: ISS=6.6±3.8 kg; TR=7.5±5.7 kg). Repetitions-to-failure did not change in either group (∆RTF: ISS=0.0±2.1 repetitions; TR=0.0±2.3 repetitions, p>0.05). Our results suggest that addition of a loaded ISS does not affect muscular adaptations either positively or negatively in resistance-trained males.

Use of critically important antimicrobial classes early in life may adversely impact bacterial resistance profiles during adult years: potential co-selection for plasmid-borne fluoroquinolone and macrolide resistance via extended-spectrum beta-lactam use in dairy cattle.

The transfer of antimicrobial resistance genes commonly occurs via vertical and horizontal gene transfer, as such genes are often found on the same mobile genetic element. This occurrence can lead to the co-selection of resistance to antimicrobials without their application. Dairy cattle located in the south-western United States were enrolled in a matched-pair longitudinal study to evaluate the effects of a two-dose ceftiofur treatment for metritis on levels of third-generation cephalosporin resistance among faecal Escherichia coli temporally. Escherichia coli chosen for further investigation were isolated on selective media, harboured extended-spectrum beta-lactam, fluoroquinolone and macrolide resistance genes. This combination has previously been unreported; importantly, it included genes encoding for resistance to antibiotics that can only be used in dairy cattle less than 20 months of age. Fluoroquinolones, macrolides and third and higher generation cephalosporins are considered critically important and highest priority for human medicine by the World Health Organization.

Effect of orally administered sodium bicarbonate on caecal pH.

REASONS FOR PERFORMING STUDY: Caecal acidosis is a central event in the metabolic cascade that occurs following grain overload. Buffering the caecal acidosis by enterally administered sodium bicarbonate (NaHCO3 ) may be beneficial to affected horses. OBJECTIVES: To determine the effect and duration of enterally administered NaHCO3 on caecal pH in healthy horses. STUDY DESIGN: Experimental study using horses with caecal cannulas. METHODS: Nine horses had been previously fitted with a caecal cannula. Six horses received 1.0 g/kg bwt NaHCO3 and 3 control horses were given 3 l of water via nasogastric tube. Clinical parameters, water consumption, venous blood gases, caecal pH, faecal pH and faecal water content were measured at 6 h intervals over a 36 h study period. RESULTS: Horses that received enterally administered NaHCO3 had significantly increased caecal pH that lasted the duration of the study. Treated horses increased their water intake, and developed metabolic alkalaemia, significantly increased plasma sodium concentrations and significantly decreased plasma potassium concentrations. CONCLUSIONS: Enterally administered NaHCO3 may be beneficial in buffering caecal acidosis.

Co-transmission of conduct problems with attention-deficit/hyperactivity disorder: familial evidence for a distinct disorder.

Common disorders of childhood and adolescence are attention-deficit/hyperactivity disorder (ADHD), oppositional defiant disorder (ODD) and conduct disorder (CD). For one to two cases in three diagnosed with ADHD the disorders may be comorbid. However, whether comorbid conduct problems (CP) represents a separate disorder or a severe form of ADHD remains controversial. We investigated familial recurrence patterns of the pure or comorbid condition in families with at least two children and one definite case of DSM-IV ADHDct (combined-type) as part of the International Multicentre ADHD Genetics Study (IMAGE). Using case diagnoses (PACS, parental account) and symptom ratings (Parent/Teacher Strengths and Difficulties [SDQ], and Conners Questionnaires [CPTRS]) we studied 1009 cases (241 with ADHDonly and 768 with ADHD + CP), and their 1591 siblings. CP was defined as > or =4 on the SDQ conduct-subscale, and T > or = 65, on Conners' oppositional-score. Multinomial logistic regression was used to ascertain recurrence risks of the pure and comorbid conditions in the siblings as predicted by the status of the cases. There was a higher relative risk to develop ADHD + CP for siblings of cases with ADHD + CP (RRR = 4.9; 95%CI: 2.59-9.41); p < 0.001) than with ADHDonly. Rates of ADHDonly in siblings of cases with ADHD + CP were lower but significant (RRR = 2.9; 95%CI: 1.6-5.3, p < 0.001). Children with ADHD + CP scored higher on the Conners ADHDct symptom-scales than those with ADHDonly. Our finding that ADHD + CP can represent a familial distinct subtype possibly with a distinct genetic etiology is consistent with a high risk for cosegregation. Further, ADHD + CP can be a more severe disorder than ADHDonly with symptoms stable from childhood through adolescence. The findings provide partial support for the ICD-10 distinction between hyperkinetic disorder (F90.0) and hyperkinetic conduct disorder (F90.1).

The effect of growth/differentiation factor-5 deficiency on femoral composition and mechanical behavior in mice.

A subclass of the bone morphogenetic proteins (BMPs), known as growth/differentiation factors (GDFs) 5, 6, and 7, have been shown to affect several skeletal processes, including endochondral ossification, synovial joint formation, and tendon and ligament repair. Mice deficient in GDF-5 have also been shown to exhibit biomechanical abnormalities in tendon that may be associated with altered type I collagen. The purpose of this study was to investigate the effect of GDF-5 deficiency on another type I collagen-rich tissue: cortical bone. Analyses were performed on femora from 8-week-old GDF-5-deficient male brachypodism mice. We hypothesized that GDF-5-deficient bones would exhibit altered geometric, structural, and material properties compared with control littermates. Mutant animals were significantly smaller in body mass than controls (-21%). Geometrically, mutant long bones were significantly shorter (-25%), had a lower polar moment of inertia (-34%), and a lower geometric strength indicator (analogous to the section modulus of a circular section) (-30%). When normalized by body mass, however, geometric differences were no longer significant. Structurally, GDF-5-deficient femora were weaker (-31%) and more compliant (-57%) than controls when tested to failure in torsion. Lower bone structural stiffness in the mutants was not completely explained by the smaller bone geometry, because mutant bones exhibited a significantly lower effective shear modulus (-36%). Although body mass did not fully explain the reduced structural strength in mutant bones, strength differences were adequately explained by bone cross-sectional geometry; maximum effective shear stress was not significantly different between mutants and controls, despite a statistically significant 6% lower ash fraction in mutant femora. No significant difference was detected in collagen content, as indicated by hydroxyproline per dry mass.

Successful hazard analysis critical control point implementation in the United Kingdom: understanding the barriers through the use of a behavioral adherence model.

Hazard analysis critical control point (HACCP), a system of risk management designed to control food safety, has emerged over the last decade as the primary approach to securing the safety of the food supply. It is thus an important tool in combatting the worldwide escalation of foodborne disease. Yet despite wide dissemination and scientific support of its principles, successful HACCP implementation has been limited. This report takes a psychological approach to this problem by examining processes and factors that could impede adherence to the internationally accepted HACCP Guidelines and subsequent successful implementation of HACCP. Utilizing knowledge of medical clinical guideline adherence models and practical experience of HACCP implementation problems, the potential advantages of applying a behavioral model to food safety management are highlighted. The models' applicability was investigated using telephone interviews from over 200 businesses in the United Kingdom. Eleven key barriers to HACCP guideline adherence were identified. In-depth narrative interviews with food business proprietors then confirmed these findings and demonstrated the subsequent negative effect(s) on HACCP implementation. A resultant HACCP awareness to adherence model is proposed that demonstrates the complex range of potential knowledge, attitude, and behavior-related barriers involved in failures of HACCP guideline adherence. The model's specificity and detail provide a tool whereby problems can be identified and located and in this way facilitate tailored and constructive intervention. It is suggested that further investigation into the barriers involved and how to overcome them would be of substantial benefit to successful HACCP implementation and thereby contribute to an overall improvement in public health.

Evolution of enzymatic activity in the enolase superfamily: structure of o-succinylbenzoate synthase from Escherichia coli in complex with Mg2+ and o-succinylbenzoate.

The X-ray structures of the ligand free (apo) and the Mg(2+)*o-succinylbenzoate (OSB) product complex of o-succinylbenzoate synthase (OSBS) from Escherichia coli have been solved to 1.65 and 1.77 A resolution, respectively. The structure of apo OSBS was solved by multiple isomorphous replacement in space group P2(1)2(1)2(1); the structure of the complex with Mg(2+)*OSB was solved by molecular replacement in space group P2(1)2(1)2. The two domain fold found for OSBS is similar to those found for other members of the enolase superfamily: a mixed alpha/beta capping domain formed from segments at the N- and C-termini of the polypeptide and a larger (beta/alpha)(7)beta barrel domain. Two regions of disorder were found in the structure of apo OSBS: (i) the loop between the first two beta-strands in the alpha/beta domain; and (ii) the first sheet-helix pair in the barrel domain. These regions are ordered in the product complex with Mg(2+)*OSB. As expected, the Mg(2+)*OSB pair is bound at the C-terminal end of the barrel domain. The electron density for the phenyl succinate component of the product is well-defined; however, the 1-carboxylate appears to adopt multiple conformations. The metal is octahedrally coordinated by Asp(161), Glu(190), and Asp(213), two water molecules, and one oxygen of the benzoate carboxylate group of OSB. The loop between the first two beta-strands in the alpha/beta motif interacts with the aromatic ring of OSB. Lys(133) and Lys(235) are positioned to function as acid/base catalysts in the dehydration reaction. Few hydrogen bonding or electrostatic interactions are involved in the binding of OSB to the active site; instead, most of the interactions between OSB and the protein are either indirect via water molecules or via hydrophobic interactions. As a result, evolution of both the shape and the volume of the active site should be subject to few structural constraints. This would provide a structural strategy for the evolution of new catalytic activities in homologues of OSBS and a likely explanation for how the OSBS from Amycolaptosis also can catalyze the racemization of N-acylamino acids [Palmer, D. R., Garrett, J. B., Sharma, V., Meganathan, R., Babbitt, P. C., and Gerlt, J. A. (1999) Biochemistry 38, 4252-4258].

Effect of extracellular potassium concentration on the sodium-potassium pump rate in human lymphocytes.

1. The purpose of this study was to determine whether physiological changes in extracellular free [K+] cause significant changes in the Na(+)-K+ pump rate and intracellular free [Na+]. 2. The Na(+)-K+ pump rate was measured in human lymphocytes by determining ouabain-sensitive 86Rb+ influx at several concentrations of K+. The Na(+)-K+ pump rate increased within the physiological range of extracellular free [K+] (K1/2 = 1.5 mmol/l). 3. To test the hypothesis that elevation of extracellular free [K+] reduces intracellular free [Na+] rapidly, which in turn then slows the pump rate during experimental incubations, lymphocyte intracellular free [Na+] was measured using the fluorochrome sodium-binding benzofuran isophthalate. With larger elevations of extracellular free [K+], intracellular free [Na+] dropped more rapidly. Thus previous discrepancies among determinations of K1/2 may be the result of variations in incubation times, which can skew the pump rates measured during incubations in various extracellular free [K+] values. Steady-state intracellular free [Na+] varied inversely with extracellular free [K+].

Effect of growth hormone therapy in men with severe idiopathic oligozoospermia.

Some studies have suggested that growth hormone (GH) may enhance folliculogenesis in women, and similarly may enhance spermatogenesis in men with hypogonadotrophic hypogonadism. In this prospective open-controlled pilot study, we investigated the effect of daily subcutaneous GH for 5 months in 12 endocrinologically normal men with severe idiopathic oligozoospermia (< 10 million/ml). All the men had normal karyotype and endocrine tests, including a GH response of > 20,000 mU/l to insulin hypoglycaemia. Nine men with similar sperm counts acted as controls. During treatment, each patient was examined monthly, asked for side effects and had glycosylated haemoglobin, glucose and blood counts monitored. Five semen samples were obtained in the 4 months before treatment, two samples per month during treatment and three samples after stopping treatment. The mean insulin-like growth factor I (IGF-I) was normal before treatment and 1 month after ending treatment, at 206 and 182 micrograms/l, respectively, but increased significantly during treatment to 444 micrograms/l (p < 0.0001, ANOVA). The mean (SD) sperm counts were 2.6 (2.5), 2.5 (3.7) and 2.3 (2.1) million/ml before, during and after GH treatment, respectively, and did not show any statistically significant differences (ANOVA). We conclude that GH does not increase or decrease sperm counts in men with severe idiopathic oligozoospermia.

Hyperactivity in school-age boys and subsequent risk of injury.

Hyperactive boys between 6 and 8 years of age, identified through systematic population-based screening of a community in London, were compared prospectively with a nonhyperactive control group to determine whether they were at greater risk of sustaining injuries. The study sample was drawn from 1296 completed parent and teacher questionnaires. Hyperactive groups were designated in three ways (parental report, teacher report, and combined parent and teacher report). Injuries were assessed by reviewing the medical records of the five emergency departments serving the community. Although boys with conduct problems did sustain more injuries than control subjects, no relationship between hyperactivity and injury was found. Similarly, when milder injuries were excluded from the analysis, the association remained negative. The absence of an association could not be accounted for by differential parental protectiveness of boys designated hyperactive. This study, which has a power of .80 to determine an increase in the relative risk of injury of 1.5, found no effect for hyperactive behavior in boys. Hyperactive behavior is probably not a risk factor for injury; if it is, it exerts a modest effect, less than 1.5, therefore accounting for less than 4% of injuries to school-aged boys.

Central venous access in children via the external jugular vein.

Sixty-two children undergoing cardiac surgery were surveyed for the presence of external jugular veins. When present, these were used as a route for central venous catheterisation using a 'J' wire Seldinger technique. Only 54% of attempted insertions were successful but the results support greater efficacy in older children.

Gastrostomy buttons for feeding children on continuous cycling peritoneal dialysis.

The promotion of growth in infants and young children with chronic renal failure (CRF) requires an aggressive approach to feeding, often in combination with early dialysis. Supplementary feeding has usually involved the use of nasogastric tubes, but these can have many problems. We report our experience with a gastrostomy button device (Bard Ltd.) for long term feeding. Ten children (7 male) had an initial gastrostomy catheter inserted at a median age of 2.0 years (range 0.25-8.5 years). None of the children required an operation for gastrooesophageal reflux and 6 had placement of the gastrostomy catheter at the time of insertion of the Tenckhoff catheter for continuous cycling peritoneal dialysis (CCPD). The catheter is usually exchanged for a similar sized (18 gauge) button device after 4 weeks. All ten children received CCPD in addition to overnight feeding using an enteral feeding pump. The buttons have been in use for a mean of 12 months (range 2-33 months) and are only changed if the anti-reflux valves fail. Nutritional goals have been achieved and growth parameters maintained or improved in 9 children. The button has many advantages over nasogastric tubes or gastrostomy catheters. It has been welcomed by our families in reducing the stress of feeding these young children.

The differentiation of asaccharolytic anaerobic gram-positive cocci by protein electrophoresis.

Conventional biochemical and antibiotic sensitivity tests were used to allocate 87 clinical isolates of anaerobic gram-positive cocci to currently recognised species, in comparison with type and other authentic reference strains. Whole-cell protein electrophoresis was then performed with extracts of each strain. Allowing for difficulties of standardisation, it was possible to allocate most of the organisms to species-related groups on the basis of protein patterns. Organisms identified conventionally as Peptostreptococcus anaerobius and P. micros formed homogeneous groups by protein electrophoresis. There was evidence for heterogeneity amongst strains identified as P. asaccharolyticus (two groups, including P. indolicus), P. prevotii and P. magnus. However, aberrant P. prevotii strains were allocated to the P. asaccharolyticus groups, leaving a homogeneous P. prevotii group, and if P. variabilis were re-instated as a species, the remaining P. magnus strains could be divided into two groups. Of the anaerobic gram-positive cocci in the National Collection of Type Cultures deposited by Hare, Group IV is P. magnus, Group IX is P. micros and Groups I, III and VIII appear to be related to the butyrate-producing species P. asaccharolyticus and P. prevotii, but are strongly saccharolytic.

Endothelin-1 mRNA expression in the rat kidney.

Cultured pig and bovine endothelial cells are capable of synthesizing endothelin-1 (ET-1). Thus the observation that the kidney contains a large number of binding sites for ET distributed in close proximity to endothelial cells suggests that ET-1 may be released from the endothelium to act locally on these receptors. In support of this hypothesis, using the technique of reverse transcription with specific amplification of cDNA, we report here that ET-1 mRNA is expressed in the rat kidney. The partial sequence of the amplified rat ET-1 cDNA confirms that the mature rat peptide is identical to that of the mouse, man and pig, but with some differences in codon usage.

Hyperinsulinaemia in thyrotoxic hypokalaemic periodic paralysis.

To test the hypothesis that there is an abnormal serum insulin response to a carbohydrate load in thyrotoxic hypokalaemic periodic paralysis (THPP), 18 men with THPP and 15 with uncomplicated thyrotoxicosis were studied during an oral glucose tolerance test. The THPP group had significantly higher fasting insulin concentrations (27.6 [3.6] vs 13.4 [1.8] mU/l; p less than 0.005) and a higher overall insulin response to oral glucose (p less than 0.001 by ANOVA) than the thyrotoxicosis group. There were no significant differences in fasting or stimulated glucose. Hyperinsulinaemia may be an important factor in the precipitation of acute paralysis in THPP.

Influence of family history of cryptogenic hypertension, age, sex and race on lymphocyte sodium/potassium pumps.

To determine the effects of age, sex, race, and family history of hypertension on cellular cation transport, we measured specific tritiated-ouabain binding (sodium/potassium pump number), and sodium/potassium pump-mediated rubidium-86 uptake in blood lymphocytes from 105 healthy normotensive adults, comprising 23 Chinese and 19 Indian subjects who had first-degree relatives with cryptogenic hypertension, and 40 Chinese and 23 Indian matched subjects without such history. Both Chinese and Indian subjects with family history had significantly fewer sodium/potassium pumps than control subjects. Sodium/potassium pump-mediated rubidium-86 uptake was similar in these four subject groups. Seven Indian patients with untreated cryptogenic hypertension had fewer sodium/potassium pumps than normotensive Indians without family history. Age did not affect sodium/potassium pump numbers in cells from normotensive subjects. In normotensive subjects without family history. Chinese women had more sodium/potassium pumps than Chinese men, but Indian subjects did not show this pattern. We conclude that a family history of cryptogenic hypertension is associated with fewer lymphocyte sodium/potassium pumps than normal. The reduction in cellular pump number might be only a marker, or an epiphenomenon. However, the reduction in pump number might contribute to the pathogenesis of cryptogenic hypertension if it produces sodium retention in renal tubular or peripheral vascular cells.