Multifidus muscle cross-sectional area adaptations over two volleyball seasons and one off-season in athletes with and without low back pain.

BACKGROUND: The multifidus muscle is important in spine stabilization. Atrophy of the multifidus muscle has been associated with low back pain. OBJECTIVE: To examine multifidus muscle cross-sectional area (CSA) adaptations over two volleyball seasons and one off-season in volleyball athletes experiencing low back pain or no low back pain. METHODS: Twelve female NCAA division 1 volleyball athletes participated. Athletes were placed into a low back pain or no low back pain group. Athlete's multifidus was imaged and measured using ultrasound at four time points across seasons. Imaging time points were before season one, following season one, following off-season, and following season two. A single level mixed-model analysis of variance was used for all analyses. A Tukey HSD post hoc test was used to determine differences between and within the low back pain and the no low back pain groups. RESULTS: Following off-season training the pain group had clinically significant smaller multifidus CSA at the L4 (-2.36 cm2 difference or 17.5%) and L5 (-2.40 cm2 or 12.5%) levels. Non-significant (p> 0.05) decreases in multifidus CSA were seen in both groups following season one and two. Athletes with pain had decreased multifidus CSA at the L4 and L5 vertebral levels at all time points which was non-significant (p> 0.05). CONCLUSIONS: Clinically significant decreases in multifidus CSA occurred in female volleyball athletes with low back pain at the L4 and L5 level following off-season training. Volleyball athletes with pain had smaller multifidus CSA averages at all time points measured of the two year period.

The Effects of a Transition to Minimalist Shoe Running on Intrinsic Foot Muscle Size.

A proposed benefit of minimalist shoe running is an increase in intrinsic foot muscle strength. This study examined change in intrinsic foot muscle size in runners transitioning to Vibram FiveFingers™ minimalist shoes compared to a control group running in traditional running shoes. We compare pre-transition size between runners who developed bone marrow edema to those who did not. 37 runners were randomly assigned to the Vibram FiveFingers™ group (n=18) or control group (n=19). Runners' bone marrow edema and intrinsic foot muscle size were measured at baseline and after 10 weeks. Total running volume was maintained by all runners. A significant increase in abductor hallucis cross-sectional area of 10.6% occurred in the Vibram FiveFingers™ group compared to the control group (p=0.01). There was no significant change in any of the other muscles examined (p>0.05). 8 of the Vibram FiveFingers™ runners, and 1 control runner developed bone marrow edema. Those who developed bone marrow edema, primarily women, had significantly smaller size in all assessed muscles (p≤0.05). Size of intrinsic foot muscles appears to be important in safely transitioning to minimalist shoe running. Perhaps intrinsic foot muscle strengthening may benefit runners wanting to transition to minimalist shoes.

Ten-year cardiovascular risk assessment in university students.

Cardiovascular disease (CVD) is responsible for more than half of all deaths in the European region. The aim of the study was to compare body composition, blood pressure, total cholesterol (TC) and high density lipoprotein cholesterol (HDL-C), family history, activity behaviors, and the 10-year risk of having a heart attack between 166 university students (21.62 ± 2.59 yrs) from Utah (USA) and 198 students (22.11 ± 2.51 yrs) from Hungary. Ninety-two percent of the Hungarian students and 100% of the Utah students had an estimated 10-year Framingham risk score of 1% or less. The high prevalence of low risk was primarily due to the young age of study participants, healthy body composition and non-smoking behavior. Hungarians who had higher 10-year risk of heart attack had significantly higher waist hip ratio (WHR), TC, diastolic blood pressure (DBP) and were smokers compared to those Hungarians with lower risk. The self-reported physical activity levels between the two groups of students were not different. In conclusion the young men and women who participated in this study were, for the most part healthy; however the smoking habits and the lower physical activity of the Hungarian students likely elevated their risk of CVD.

Effects of serum response factor (SRF) deletion on conditioned reinforcement.

Serum response factor (SRF) is a ubiquitously expressed stimulus-dependent transcription factor that regulates gene expression by binding to serum response element in the promoter region of target genes. Recent studies in mice have shown that SRF is important for activity-dependent gene expression and synaptic plasticity in the adult brain but is dispensable for neuronal survival. Given these important functions of SRF in the CNS, it is expected to play a critical role in several aspects of learning and memory. Here we evaluated the role of SRF in conditioned reinforcement using two lines of conditional SRF mutant mice. These SRF mutant mice exhibited different spatial patterns of SRF deletion in the post-natal forebrain and notably within the hippocampus. SRF deletion was more widespread in SRF-CKCre mutants than in SRF-SynCre mutants, particularly in areas of the cortex and striatum. Mutant and wild-type mice were trained to associate one auditory cue (CS+) with reward, whereas a second cue remained relatively neutral (CS-). All mice readily acquired this discrimination, entering the food cup during CS+ but not during CS-. In a subsequent test of conditioned reinforcement, in the absence of food, wild-type control mice and SRF-SynCre mice learned to selectively perform an instrumental response that yielded CS+ presentation rather than another response that produced CS-. SRF-CKCre mutants failed to show this preferential responding for CS+. These results suggest a role for SRF in conditioned reinforcement, a manifestation of incentive learning that has been implicated in many aspects of adaptive and maladaptive behavior, such as substance abuse and eating disorders.

Whole body vibration as an adjunct to static stretching.

This study was a randomized control trial. The purpose of this study was twofold: 1) to determine if stretching the hamstrings during whole-body-vibration (WBV) is more effective than static stretching alone; and 2) to monitor retention of flexibility changes. The main outcome measure was hamstring flexibility as measured in degrees using a passive knee extension test. Thirty-four recreationally active college-age subjects (23.4+/-1.7 yrs) completed this study (22 males, 12 females, avg. ht.=175.6+/-6.4 cm, avg. wt.=74.9+/-11.8 kg). Subjects were assigned to a control group (C), a static stretch group (SS), or a vibration + static stretch group (V). Subjects stretched 5 days/wk for 4-weeks and were followed for 3-weeks after cessation to monitor retention. Analysis showed a significant difference between treatment groups (p<0.0001), time (p<0.0001), gender (p=0.0002) and in treatment*time (p=0.0119), with 14%+/-3.86% (SEM) and 22%+/-3.86% (SEM) increases in flexibility after 4-weeks of stretching for the SS and V groups respectively. Three-week follow-up showed SS returning to baseline with V group still 6.4 degrees (11%+/-3.88% (SEM)) more flexible than at baseline. Stretching concurrently with vibration on a WBV platform appears to be a good adjunct to static stretching with the potential to enhance retention of flexibility gains.

An analysis of licking microstructure in three strains of mice.

Mouse models of feeding provide a useful tool for elucidating the molecular pathways of energy regulation. The majority of studies in mice have been limited to intake analyses conducted over extended periods of time, which fail to distinguish between a variety of factors that influence nutrient intake. Using licking microstructure analyses we examined both the size and number of licking bursts for water, polycose, sucrose and lecithin in three strains of mice (C57BL/6J, 129Sv/ImJ and C57129F1 hybrids), using pause criteria (250-500, >500 and >1000 ms) that have previously been described in the rat. Burst size and number varied both as a function of tastant concentration and mouse strain; however, these differences were most evident with the >1000 ms pause criterion. Consistent with previous reports, during water consumption C57 mice showed longer mean interlick intervals, a larger number of bursts but reduced burst size relative to the two other strains. F1 mice showed larger burst sizes for polycose, while C57 mice displayed a greater number of bursts for both polycose and sucrose. Both 129 and F1 mice were insensitive to sucrose concentration, whereas C57 mice showed attenuated lecithin intake influenced by a reduction in the size of bursts for this tastant. These results suggest that these strains of mice display differences in the pattern of licking that are most evident with the use of larger pause criteria. These differences in licking behavior might reflect influences of genetic background on pre- and post-ingestive factors controlling intake, the reinforcing properties of each tastant, or native differences in licking style.

The diagnostic value of the triple bubble sign in proximal jejunal atresia: a case report.

Proximal jejunal atresia (PJA) is a common cause of intestinal obstruction in the newborn. Despite the need for an early surgical intervention to minimize morbidity and mortality, a timely identification is frequently precluded by the absence of specific clinical and investigative clues. Against the background of the limitations in making a timely diagnosis of PJA in a tropical setting, where opportunities for high-tech imaging tools are few, we report the diagnostic value of the "triple bubble" sign on the plain radiograph of a Nigerian infant. This radiologic finding led to an early diagnosis and ultimately a prompt surgical extirpation. The paper suggests that the presence of this sign should be a pointer to an early diagnosis of PJA.

Measuring the PSF from aperture images of arbitrary shape--an algorithm.

A new algorithm for determining the point spread function (PSF) of digital imaging systems is presented. The input is an image of an aperture whose shape need not be regular. The aperture shape is refined to an effective sub-pixel resolution and the PSF of the system is determined by de-convolution, assuming uniform illumination and a step function edge. The method has been tested on theoretical aperture images of varying shape and PSF, with and without noise. Depending on the degree of noise, a known PSF can be recovered to an accuracy of between 0.2 and 0.8%. Some typical results are given for a Gatan Image Filter with a 794 YAG multiscan camera on a Philips EM 430 transmission electron microscope at 200 and 300 kV. An example of a de-convoluted convergent beam electron diffraction pattern is included. The algorithm tolerates a small amount of de-focus.

Evaluation of Pearl Millet Grain Hybrids for Resistance to Meloidogyne spp. and Leaf Blight Caused by Pyricularia grisea.

Pearl millet, Pennisetum glaucum, has potential as a grain crop in the southeastern United States. Our objectives were to (i) determine the resistance and/or tolerance of pearl millet hybrids to Meloidogyne incognita race 3 and M. arenaria race 1; (ii) compare reproduction of Meloidogyne spp. on pearl millet and corn; and (iii) determine the disease severity of leaf blight caused primarily by Pyricularia grisea. In a field naturally infested with M. incognita, experimental pearl millet hybrids with inbreds 114 and 117 as the pollinators had fewer numbers of second-stage juveniles and more severe leaf blight than did HGM-100, a nematode-susceptible hybrid; hybrids with inbred 115 as the pollinator were similar to HGM-100 in both nematode numbers and foliar disease severity. Grain yields in pearl millet were greater in plots treated with 1,3-dichloropropene than in control plots and were negatively correlated with leaf blight severity. In a greenhouse experiment, both M. incognita and M. arenaria produced fewer eggs on pearl millet hybrids with pollinators 114, 117, 101, 102, and 103 than on hybrid HGM-100. Reproduction of M. incognita was less on the resistant pearl millet hybrids than on corn. Because both M. incognita and P. grisea can reduce grain yield of pearl millet, hybrids developed for the southeastern United States should be resistant to both pathogens.

Survival and development of Heliothis virescens (Lepidoptera: Noctuidae) larvae on isogenic tobacco lines with different levels of alkaloids.

Levels of pyridine alkaloids were measured in 18 tobacco, Nicotiana tabacum L., entries from three parental isolines ('NC 95', 'SC 58', and 'Coker 139'), grown at Tifton, GA, Florence, SC, and Oxford, NC, in 1991. Levels of alkaloids in bud leaves (first fully unfolded leaf below the apical leaf bud) were negatively correlated to natural infestation ratings of tobacco budworm larvae, Heliothis virescens (F.), 7 wk after transplanting. For artificially infested bud leaves at Oxford, there was a significant negative correlation between levels of total alkaloids and larval weights after 1 wk of feeding. In 1992, four entries from the 'NC 95' isoline were grown at Oxford, and samples for alkaloid analyses were taken every 2 wk at several leaf positions on each plant. During weeks 4, 8, 12, and 16, second instar tobacco budworms were caged on individual, intact leaves inside perforated plastic bags in the field. The survival and development of tobacco budworm larvae after 1 wk were negatively correlated with levels of alkaloids at the various leaf positions. Larvae survived better and grew faster on the bud leaves of each entry where alkaloid levels were lower than they did on leaves further down the stalk where alkaloid levels were higher. More larvae survived on the lower leaves of the low alkaloid lines than on the lower leaves of the high alkaloid lines. Even moderate increases in pyridine alkaloids had negative effects on tobacco budworm survival and development. Nicotine constituted >97% of the pyridine alkaloids in the 'NC95' isoline each year.

Typhoid ileal perforation in Nigerian children: an analysis of 106 operative cases.

Typhoid ileal perforation (TP) is a major problem in developing countries and carries a high mortality. The purpose of this retrospective study from Nigeria was to review the outcome in children less than 15 years of age who underwent surgery for TP from 1984 to 1999. Demographic data, clinical features, results of investigations, findings at surgery, postoperative course, and complications were recorded. There were 55 boys and 51 girls. The median age at presentation was 10 years (range 3-14). The surgically confirmed perforation rate was 11.0%. The clinical features in children older than 5 years were similar to already documented patterns in the literature. In children less than 5 years old the predominant symptoms were fever and vomiting only. Therefore, in the very young a high index of suspicion is required to avoid delay in diagnosis. Ninety eight patients (92.5%) had simple double-layer closure of the perforation. The mean hospital stay among survivors was 23.6 +/- 18.8 days. The commonest postoperative complications were wound infection and enterocutaneous fistula. The overall mortality was 23.8%, increasing to 50% in children aged less than 5 years, although the difference was not statistically significant (P > 0.05). To improve survival in TP, attention should be focused on perioperative resuscitation and early intervention. The provision of potable water, adequate sanitation, and active immunisation are means to eradicate the disease.

Effects of phytanic acid on the vitamin E status, lipid composition and physical properties of retinal cell membranes: implications for adult Refsum disease.

Adult Refsum disease is an inherited disorder in which phytanic acid accumulates in tissues and serum. Two hypotheses have been proposed to explain the pathogenesis of this condition. The molecular distortion hypothesis suggests that phytanic acid may alter membrane composition and structure, thereby affecting membrane function(s). The anti-metabolite hypothesis suggests that an accumulation of phytanic acid in membranes may interfere with vitamin E function. These two hypotheses were investigated by studying the effects of modulating phytanic acid and alpha-tocopherol concentrations on the fatty acid composition and certain physical parameters of cultured retinal cells. Results showed that (a) the phospholipid fraction of retinal cells readily incorporated phytanic acid, (b) the incorporation of phytanic acid increased membrane fluidity, (c) there was no competition for uptake between phytanic acid and alpha-tocopherol, and (d) the incorporation of phytanic acid did not increase the susceptibility of membranes to lipid peroxidation in vitro. These results obtained with cultured retinal cells suggest that the molecular distortion hypothesis, but not the anti-metabolite hypothesis, could explain the pathogenesis of adult Refsum disease. In vitro tissue culture models can, however, only approximate to the much more complex situation that occurs in vivo.

A cis-acting element known to block 3' mRNA degradation enhances expression of polyA-minus mRNA in wild-type yeast cells and phenocopies a ski mutant.

mRNA lacking a 3' polyA tail is not translated efficiently in wild-type eukaryotic cells, but is translated efficiently in yeast ski mutants. This enhanced expression could be due to altered translational specificity. However, as the SKI genes are required for 3' mRNA degradation, it could be a consequence of inhibition of 3' mRNA decay. Therefore, we asked if inhibition of 3' decay of a polyA-minus mRNA in cis would allow its efficient expression in wild-type cells. Capped in vitro reporter transcripts were prepared with or without a 3' cis-acting element known to inhibit 3' degradation (oligoG) and electroporated into yeast cells. The addition of oligoG to a polyA-minus mRNA enhanced expression 30-fold in wild-type cells. This level of expression was the same as that for an oligoG-minus, polyA-minus transcript in a ski mutant. The addition of oligoG did not significantly enhance the expression of polyA-minus mRNA in a ski mutant. The oligoG-dependent increase in expression was due to an increase in initial rate of translation and an increase in the functional half-life of the mRNA, similar to the effects observed in a ski mutant. The enhanced expression of the oligoG-containing RNA did not require Pab1p. We conclude that the enhanced translation of polyA-minus RNA in a ski mutant is due to inhibition of 3' mRNA degradation. Furthermore, a polyA-minus mRNA is expressed in wild-type cells when terminated in an element known to inhibit 3' decay in cis.

Analysis by matrix assisted laser desorption/ionisation-time of flight mass spectrometry of the post-translational modifications of alpha 1-antitrypsin isoforms separated by two-dimensional polyacrylamide gel electrophoresis.

The state of protein glycosylation in terms of occupation of potential N-linked glycosylation sites (macroheterogeneity) and type of glycosylation at that site (microheterogeneity) is important when investigating the consequences of aberrant glycosylation in the pathophysiology of disease. Protocols have been developed to permit characterisation of the site-specific glycosylation of individual isoforms of glycoproteins after separation by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and analysis of the peptide mixture by peptide mass fingerprinting using matrix-assisted laser desorption/ionisation-time of flight mass spectrometry (MALDI-TOF). High resolution of the individual isoforms of alpha 1-antitrypsin was achieved by using narrow range (4.5-5.5) p/strips. The individual isoforms were then subjected to sequential digestion with a recombinant N-glycanase followed by a protease. Using this strategy it was possible not only to increase the coverage of the amino acid sequence but also to monitor the occupancy of all three putative N-linked glycosylation sites. Glycans were enzymatically released from alpha 1-antitrypsin which had been separated in gels formed with a low percentage of bis-acrylamide cross-linker and analysed. Profiles of the N-linked glycans of the individual isoforms of alpha 1-antitrypsin were obtained by MALDI-TOF.

Identification of alpha(1)-antitrypsin variants in plasma with the use of proteomic technology.

BACKGROUND: Proteomic technology permits the investigation of genetic metabolic diseases at the level of protein expression. Changes in the expression, polypeptide structure, and posttranslational modification of individual proteins can be detected in complex mixtures of proteins. METHODS: We used high-resolution two-dimensional polyacrylamide gel electrophoresis to separate isoforms of plasma proteins and detect abnormalities of mass and/or charge. We confirmed the identity of the separated proteins by in-gel digestion with proteases and N-glycanases and then analyzed the released peptides and glycans by matrix-assisted laser-desorption ionization-time-of-flight mass spectrometry. RESULTS: Complete characterization of the polypeptide sequences and glycosylation of alpha(1)-antitrypsin isoforms was achieved in plasma from controls and from patients with three different known alpha(1)-antitrypsin deficiencies and congenital disorder of glycosylation type Ia. CONCLUSIONS: This study shows that proteomic techniques are a powerful and sensitive means of detecting changes in the amino acid sequence and abnormal posttranslational modifications of specific proteins in a complex biologic matrix.

Stress fractures of the sacrum. An atypical cause of low back pain in the female athlete.

Low back pain is a common finding in an athletically active premenopausal female population. We describe an unusual cause of persistent low back/sacroiliac pain: a fatigue-type sacral stress fracture. Plain radiographs, bone scans, computed tomography, and magnetic resonance imaging studies were obtained in the female athletes to determine the nature of the pathologic abnormality. The most significant risk factor for fatigue-type sacral stress fractures was an increase in impact activity due to a more vigorous exercise program. Potential risk factors such as abnormal menstrual history, dietary deficiencies, and low bone mineral density were examined. The clinical course was protracted, with an average 6.6 months of prolonged low back pain before resolution of symptoms. Sacral fatigue-type stress fractures did not preclude the athletes from returning to their previous level of participation once healing had occurred.

Russell-Silver Syndrome in a Nigerian infant with intrauterine growth retardation.

Russell-Silver Syndrome (RSS) is a rare cause of pre-natal dwarfism, associated with recognizable dysmorphic features and limb asymmetry. The propositus was a term infant of unrelated Nigerian parents, whose 35-year-old mother had peri-conceptual haloperidol for schizophrenia. Anthropometric values suggested severe prenatal stunting in a term infant with asymmetric "head sparing" intrauterine growth retardation (IUGR). A syndromic consideration of Russell-Silver dwarfism was subsequently predicated on the distinctive dysmorphic craniofacial features of a triangular facial profile with a broad forehead and hypoplastic mandible, right upper and lower limb rhizomelia, clinodactyly of the little fingers, micro-penis, and (unilateral) cryptochidism. Routine care of a small-for-gestational-age infant was pursued, but postnatal growth remained slow (despite adequate caloric provision) until a parent-pressured discharge at 4 weeks. His subsequent demise was said to have occurred "suddenly" 2 weeks post-discharge. Despite the limitations posed by the local paucity of modern investigative tools for genetic disorders, the current case report underscores the diagnostic reality of RSS in a non-white African population. While emphasizing the need for a high index of diagnostic suspicion for congenital malformations and syndromic causes of IUGR in the African sub-region, we suspect a possible etiologic association of haloperidol embryopathy with RSS in the current case. The characteristic features, differential diagnoses, etiologic postulates/current cytogenetic and molecular genetic findings of RSS are fully reviewed in the discussion.