Classification of the reduced vertical component of the ground reaction force in late stance in cerebral palsy gait

Children with cerebral palsy (CP) often experience significant problems supporting their bodyweight (BW) and decelerating the downward velocity of the centre of mass (CoM) in late stance. This is seen as a decreased second peak of vertical ground reaction force (GRF) nominated FZ(2). This study categorises gait data by the degree of reduced FZ(2). Kinetic data were analysed from a CP database. Data from 129 patients, able to walk barefoot unaided, were investigated. Of these, 84 had kinetic data, 59 diplegics (both legs) and 15 hemiplegics (affected leg only), thus providing data from 133 legs. A reduced FZ(2) was observed in 116 legs (87%). Of the 133 legs, 44% failed to generate FZ(2)>BW. By including the Type 2 data this figure rises to, a staggering 66% who are having difficulty supporting BW at this stage of the stance phase. Only 12% of the legs showed a normal pattern (FZ(2) approximately equal to FZ(1)). In conclusion, the majority of CP children referred to the gait laboratory exhibited some degree of reduced FZ(2) and can be categorised as having a 'Ben Lomonding' gait pattern. 'Ben Lomonding,' is the term used to describe this phenomenon of reduced FZ(2), as the shape of the GRF graph resembles the shape of the Scottish mountain, Ben Lomond, which has two peaks, the second peak being much smaller than the first. Crucially, clinicians should be aware that nearly half of the CP children in this study were in difficulty supporting their BW in late stance and must use compensatory mechanisms to prevent collapse of the affected limb.

Measuring athlete imagery ability: the sport imagery ability questionnaire

This research aimed to develop and provide initial validation of the Sport Imagery Ability Questionnaire (SIAQ). The SIAQ assesses athletes' ease of imaging different types of imagery content. Following an extensive pilot study, 375 athletes completed a 20-item SIAQ in Study 1. Exploratory factor analysis revealed a 4-factor model assessing skill, strategy, goal, and affect imagery ability. Confirmatory factor analysis (CFA) established this 4-factor structure in Study 2 (N = 363 athletes). In Study 3 (N = 438 athletes), additional items were added to create a fifth mastery imagery subscale that was confirmed through CFA. Study 4 (N = 220 athletes) compared the SIAQ to the Movement Imagery Questionnaire-3. Significant bivariate correlations (p < .05) confirmed the SIAQ's concurrent validity but demonstrated differences in imagery ability of different content. Overall, the SIAQ demonstrates good factorial validity, internal and temporal reliability, invariance across gender, and an ability to distinguish among athletes of different competitive levels. Findings highlight the importance of separately assessing imagery ability of different content.

Leaf closure in the venus flytrap: an Acid growth response

The rapid closure of leaves in the Venus flytrap (Dionaea muscipula) involves irreversible cell enlargement, which can be initiated by acidifying the cell walls to pH 4.50 and below. Leaves infiltrated with neutral buffers that keep the pH above 4.50 to 4.75 will not close in response to stimulation of their trigger hairs even though the action potentials that ordinarily cause closure are produced. During the 1 to 3 seconds required for closure about 29 percent of the cellular adenosine triphosphate is lost. It is likely that this adenosine triphosphate is used in very rapid transport of hydrogen ions from the motor cells and that the movement is due to a mechanism of "acid growth."

The use of imagery to manipulate challenge and threat appraisal States in athletes

The present study investigated whether imagery could manipulate athletes' appraisal of stress-evoking situations (i.e., challenge or threat) and whether psychological and cardiovascular responses and interpretations varied according to cognitive appraisal of three imagery scripts: challenge, neutral, and threat. Twenty athletes (M(age) = 20.85; SD = 1.76; 10 female, 10 male) imaged each script while heart rate, stroke volume, and cardiac output were obtained using Doppler echocardiography. State anxiety and self-confidence were assessed following each script using the Immediate Anxiety Measures Scale. During the imagery, a significant increase in heart rate, stroke volume, and cardiac output occurred for the challenge and threat scripts (p < .05). Although there were no differences in physiological response intensities for both stress-evoking scripts, these responses, along with anxiety symptoms, were interpreted as facilitative during the challenge script and debilitative during the threat script. Results support using imagery to facilitate adaptive stress appraisal.

Ecological specialization and population size in a biodiversity hotspot: how rare species avoid extinction

Species with narrow environmental niches typically have small geographic ranges. Small range size is, in turn, often associated with low local abundance. Together, these factors should mean that ecological specialists have very small total populations, putting them at high risk of extinction. But some specialized and geographically restricted species are ancient, and some ecological communities have high proportions of rare and specialized endemics. We studied niche characteristics and patterns of distribution and abundance of terrestrial vertebrates in the rainforests of the Australian Wet Tropics (AWT) to identify mechanisms by which rare species might resist extinction. We show that species with narrow environmental niches and small geographic ranges tend to have high and uniform local abundances. The compensation of geographic rarity by local abundance is exact, such that total population size in the rainforest vertebrates of the AWT is independent of environmental specialization. This effect would tend to help equalize extinction risk for specialists and generalists. Phylogenetic analysis suggests that environmental specialists have been gradually accumulating in this fauna, indicating that small range size/environmental specialization can be a successful trait as long as it is compensated for by demographic commonness. These results provide an explanation of how range-restricted specialists can persist for long periods, so that they now form a major component of high-diversity assemblages such as the AWT.

Functional MRI of working memory in paediatric head injury

A case study examining the recovery of a 9 year old boy who sustained a severe head injury is reported. The subject sustained damage to the left parietal-occipital and right frontal-parietal regions. Structural and functional imaging and cognitive data were collected at the time of injury and 1 year post-injury. Cognitive assessment revealed improvement over time. Functional imaging at the time of injury revealed minimal activation in the right posterior temporal region. Imaging 1 year post-injury revealed increased activation in the right pre-frontal cortex, bilateral pre-motor cortex and bilateral posterior parietal cortex. This activation pattern is consistent with the performance of unaffected individuals on working memory tasks. These findings differ from those in the adult literature and suggest an alternative pattern of recovery of function in children.

Identification and dynamics of a cryptic suture zone in tropical rainforest

Suture zones, shared regions of secondary contact between long-isolated lineages, are natural laboratories for studying divergence and speciation. For tropical rainforest, the existence of suture zones and their significance for speciation has been controversial. Using comparative phylogeographic evidence, we locate a morphologically cryptic suture zone in the Australian Wet Tropics rainforest. Fourteen out of 18 contacts involve morphologically cryptic phylogeographic lineages, with mtDNA sequence divergences ranging from 2 to 15 per cent. Contact zones are significantly clustered in a suture zone located between two major Quaternary refugia. Within this area, there is a trend for secondary contacts to occur in regions with low environmental suitability relative to both adjacent refugia and, by inference, the parental lineages. The extent and form of reproductive isolation among interacting lineages varies across species, ranging from random admixture to speciation, in one case via reinforcement. Comparative phylogeographic studies, combined with environmental analysis at a fine-scale and across varying climates, can generate new insights into suture zone formation and to diversification processes in species-rich tropical rainforests. As arenas for evolutionary experimentation, suture zones merit special attention for conservation.

Effects of drag factor on physiological aspects of rowing

This study examined the effects of two resistances, or "drag factors" on selected physiological variables during incremental progressive rowing tests (seven 3-min stages) on a Concept2 ergometer. Subjects were seven male and seven female university club rowers. Their mean age, body mass and height were 19.6 +/- 1.5 years, 72.7 +/- 8.0 kg, and 172.2 +/- 7.5 cm, respectively. Progressive tests were conducted using drag factors 100 (D100) and 150 (D150) before the spring racing season. Values were determined for the following physiological variables: ventilation (V.E), oxygen uptake (V.O2), heart rate (HR), blood lactate concentration (BLC), respiratory exchange ratio (R) and rowing economy (W/V.O2). Comparisons across all six submaximal stages showed no significant difference between D(100) and D(150) for any of the variables measured (p > .05). Maximal V.E(max) was significantly greater at D100 than D150 (p < .02). Maximal V.O(2), HR, BLC, R, stroke rate (SR) and W/V.O2 were greater at D100 than at D150, though not significantly so. The mean D100-D150 differences in V.E and SR for each stage were significantly correlated (r = 0.76, p < .01), suggesting drag factor may affect V.E via SR.

ARE PIKAS EXPOSED TO AND AFFECTED BY SELENIUM DEFICIENCY?

Regional extirpations of pikas (Ochatona princeps) within the last few decades have been attributed to global warming. Other recent global alterations such as increased nitrogen (N) deposition and associated selenium (Se) deficiency may further stress pika populations. In 2003 and 2004, we live-trapped pikas from three populations in Wyoming and measured Se values in their hair. We also sampled hair and liver from museum specimens collected throughout the Northern Rocky Mountains in 1987 and 1988. Our results suggest that liver and hair values were related, and that pika hair reflected the Se concentrations of the geologic parent materials. We determined that animals residing in several remote areas in the Rocky Mountain region could be Se deficient and that increase in N deposition correlated with an increase rather than a decrease in Se values in pika hair. In addition, we found no relation between Se contents in hair and body condition index, suggesting that low Se levels may not have negative effects on individual pikas. Whether Se levels influence reproductive success of pikas is unknown and should be the focus of future studies.

Parafibromin is a nuclear protein with a functional monopartite nuclear localization signal

Parafibromin is a nuclear protein with a tumour suppressor role in the development of non-hereditary and hereditary parathyroid carcinomas, and the hyperparathyroidism-jaw tumour (HPT-JT) syndrome, which is associated with renal and uterine tumours. Nuclear localization signal(s), (NLS(s)), of the 61 kDa parafibromin remain to be defined. Utilization of computer-prediction programmes, identified five NLSs (three bipartite (BP) and two monopartite (MP)). To investigate their functionality, wild-type (WT) and mutant parafibromin constructs tagged with enhanced green fluorescent protein or cMyc were transiently expressed in COS-7 cells, or human embryonic kidney 293 (HEK293) cells, and their subcellular locations determined by confocal fluorescence microscopy. Western blot analyses of nuclear and cytoplasmic fractions from the transfected cells were also performed. WT parafibromin localized to the nucleus and deletions or mutations of the three predicted BP and one of the predicted MP NLSs did not affect this localization. In contrast, deletions or mutations of a MP NLS, at residues 136-139, resulted in loss of nuclear localization. Furthermore, the critical basic residues, KKXR, of this MP NLS were found to be evolutionarily conserved, and over 60% of all parafibromin mutations lead to a loss of this NLS. Thus, an important functional domain of parafibromin, consisting of an evolutionarily conserved MP NLS, has been identified.

Detecting cheating in written medical examinations by statistical analysis of similarity of answers: pilot study

OBJECTIVE

To assess whether a computer program using a variant of Angoff's method can detect anomalous behaviour indicative of cheating in multiple choice medical examinations.

DESIGN

Statistical analysis of 11 examinations held by the Royal College of Paediatrics and Child Health.

SETTING

UK postgraduate medical examination.

PARTICIPANTS

Examination candidates.

MAIN OUTCOME MEASURES

Detection of anomalous candidate pairs by regression of similarity of correct answers in all possible pairs of candidates on the overall proportion of correct answers. Anomalous pairs were subsequently assessed in terms of examination centres and the seating plan of candidates, to assess adjacency.

RESULTS

The 11 examinations were taken by a total of 11,518 candidates, and Acinonyx examined 6,178,628 pairs of candidates. Two examinations showed no anomalies, and one examination found an anomaly resulting from a scanning error. The other eight examinations showed 13 anomalies compatible with cheating, and in each pair the two candidates had sat the examination at the same centre, and for six examinations with seating plans, the candidates in the anomalous pairs had been seated side by side. The raw probabilities of the anomalies varied from 3.9x10(-11) to 9.3x10(-30) (median = 1.1x10(-17)), with Bonferroni-corrected probabilities in the range 2.4x10(-5) to 4.1x10(-24) (median = 1.6x10(-11)). This suggests that one anomalous pair is found for every 1000 or so candidates taking this postgraduate examination.

CONCLUSIONS

This statistical technique identified a small proportion of candidates who had very similar patterns of correctly answered questions. The likelihood is that one candidate has copied from the other, or that there was collusion, or that a technical error occurred in the exams department (as happened in a single case). Analysis of similarities can be used to identify cheating and as part of the quality assurance process of postgraduate medical examinations.

Biogeographical concordance and efficiency of taxon indicators for establishing conservation priority in a tropical rainforest biota

Prioritizing areas for conservation requires the use of surrogates for assessing overall patterns of biodiversity. Effective surrogates will reflect general biogeographical patterns and the evolutionary processes that have given rise to these and their efficiency is likely to be influenced by several factors, including the spatial scale of species turnover and the overall congruence of the biogeographical history. We examine patterns of surrogacy for insects, snails, one family of plants and vertebrates from rainforests of northeast Queensland, an area characterized by high endemicity and an underlying history of climate-induced vicariance. Nearly all taxa provided some level of prediction of the conservation values for others. However, despite an overall correlation of the patterns of species richness and complementarity, the efficiency of surrogacy was highly asymmetric; snails and insects were strong predictors of conservation priorities for vertebrates, but not vice versa. These results confirm predictions that taxon surrogates can be effective in highly diverse tropical systems where there is a strong history of vicariant biogeography, but also indicate that correlated patterns for species richness and/or complementarity do not guarantee that one taxon will be efficient as a surrogate for another. In our case, the highly diverse and narrowly distributed invertebrates were more efficient as predictors than the less diverse and more broadly distributed vertebrates.

Plasma lipids and cardiovascular risk: a POSCH report. Program on the Surgical Control of the Hyperlipidemias

Quantifying the relationship between changes in lipid variables and clinical endpoints has been difficult. We studied the predictive value of various lipid variables on three endpoints in the Program on the Surgical Control of the Hyperlipidemias (POSCH): overall mortality, coronary heart disease (CHD) mortality, and CHD mortality and confirmed nonfatal myocardial infarction (MI) combined. We measured lipid variables for the annual visits from baseline to 5 years for actual follow-up values, actual and percentage differences between baseline and follow-up values, as well as the parameters comparing baseline only to 5 years for actual differences, percentage differences, and the ratio of baseline to 5 years. The lipid variables included were total cholesterol, low density lipoprotein (LDL) cholesterol, high density lipoprotein (HDL) cholesterol, very low density lipoprotein (VLDL) cholesterol, triglycerides, and the LDL cholesterol/HDL cholesterol ratio. The analytic method used was that of Cox regression, with age and sex as secondary covariates, and each lipid or ratio of lipids as the primary (univariate) covariate. As a result, 108 univariate Cox regressions were conducted. The combined findings for the control and the intervention groups are presented. The number of events for the combined group were: overall mortality, 190; CHD mortality, 119; and CHD mortality and confirmed nonfatal MI, 262. The highest hazard ratios were found for the lipid variable of the LDL cholesterol/HDL cholesterol ratio (e.g. 1.196 for a 1-unit increase). Only for the combined endpoint of CHD mortality and confirmed nonfatal MI was there a substantial number of statistically significant relationships (P<0.01) of lipid variables and parameters of assessment.

Carcass traits, cut yields, and compositional end points in high-lean-yielding pork carcasses: effects of 10th rib backfat and loin eye area

Pork carcasses (n = 133) were used to investigate the influence of carcass fatness and muscling on composition and yields of pork primal and subprimal cuts fabricated to varying levels of s.c. fat. Carcasses were selected from commercial packing plants in the southeastern United States, using a 3 x 3 factorial arrangement with three levels of 10th rib backfat depth (< 2.03, 2.03 to 2.54, and > 2.54 cm) and three levels of loin eye area (LEA; < 35.5, 35.5 to 41.9, and > 41.9 cm2). Sides from the selected carcasses were shipped to the University of Georgia for carcass data collection by trained USDA-AMS and University of Georgia personnel and fabrication. Sides were fabricated to four lean cuts (picnic shoulder, Boston butt, loin, and ham) and the skinned belly. The four lean cuts were further fabricated into boneless cuts with s.c. fat trim levels of 0.64, 0.32, and 0 cm. The percentages of four lean cuts, boneless cuts (four lean cuts plus skinned, trimmed belly) at 0.64, 0.32, and 0 cm s.c. fat, fat-free lean, and total fat were calculated. Data were analyzed using a least squares fixed effects model, with the main effects of 10th rib backfat and LEA and their interaction. Fatness and muscling traits increased (P < 0.05) as 10th rib backfat and LEA category increased, respectively. However, fat depth measures were not affected greatly by LEA category, nor were muscling measures greatly affected by backfat category. The percentage yield of cuts decreased (P < 0.05) as backfat category increased. Cut yields from the picnic shoulder, Boston butt, and belly were not affected (P > 0.05) by LEA category, whereas the yield of boneless loin and ham increased (P < 0.05) as LEA category increased. Compositionally, the percentage of four lean cuts, boneless cuts at varying trim levels, and fat-free lean decreased incrementally (P < 0.05) as backfat depth increased, whereas parentage total fat and USDA grade increased (P < 0.05) as backfat depth increased. As LEA increased, percentage boneless cuts trimmed to 0.32 and 0 cm s.c. fat and fat-free lean increased and total fat decreased; however, the difference was only significant in the smallest LEA category. Collectively, these data show that decreased carcass fatness plays a greater role in increasing primal and subprimal cut yields and carcass composition than muscling even in lean, heavily muscled carcasses.

Retinal ganglion cell axon guidance in the mouse optic chiasm: expression and function of robos and slits

The ventral midline of the nervous system is an important choice point at which growing axons decide whether to cross and project contralaterally or remain on the same side of the brain. In Drosophila, the decision to cross or avoid the CNS midline is controlled, at least in part, by the Roundabout (Robo) receptor on the axons and its ligand, Slit, an inhibitory extracellular matrix molecule secreted by the midline glia. Vertebrate homologs of these molecules have been cloned and have also been implicated in regulating axon guidance. Using in situ hybridization, we have determined the expression patterns of robo1,2 and slit1,2,3 in the mouse retina and in the region of the developing optic chiasm, a ventral midline structure in which retinal ganglion cell (RGC) axons diverge to either side of the brain. The receptors and ligands are expressed at the appropriate time and place, in both the retina and the ventral diencephalon, to be able to influence RGC axon guidance. In vitro, slit2 is inhibitory to RGC axons, with outgrowth of both ipsilaterally and contralaterally projecting axons being strongly affected. Overall, these results indicate that Robos and Slits alone do not directly control RGC axon divergence at the optic chiasm and may additionally function as a general inhibitory guidance system involved in determining the relative position of the optic chiasm at the ventral midline of the developing hypothalamus.

Effectiveness of two cooking systems in destroying Escherichia coli O157:H7 and Listeria monocytogenes in ground beef patties

A rapid, high-temperature double-sided grilling-broiling (DGB) system was compared to a single-sided broiling (SSB) system for cooking of foodservice ground beef patties to reduce microbial numbers and maintain textural quality. Patties (110 g) containing either Escherichia coli O157:H7 or Listeria monocytogenes (10(6-7) CFU/g) were cooked to target internal temperatures of 60 or 68 degrees C on each cooking system and immediately removed from the grills without the additional holding time at 60 or 68 degrees C that is recommended for foodservice cooking of ground beef patties. Actual final internal temperature attained, position on the grill, degree of doneness, cooking time, after-cook weight, texture characteristics, and bacterial counts of the patties were monitored. The DGB reduced E. coli O157:H7 and L. monocytogenes populations in ground beef patties by 5.7 log10 and 5.4 log10 CFU/g, respectively, when cooked to a target temperature of 60 degrees C (actual final internal temperature of 71.2 degrees C) and by 6.1 log10 and 5.6 log10 CFU/g, respectively, when cooked to a target temperature of 68 degrees C (actual final internal temperature of 75.8 degree C). The SSB reduced E. coli O157:H7 and L. monocytogenes populations by 1.3 log10 and 1.8 log10 CFU/g, respectively, when cooked to a target temperature of 60 degrees C (actual final internal temperature of 62.7 degrees C) and by 2.9 log10 and 3.6 log10 CFU/g, respectively, when cooked to a target temperature of 68 degrees C (actual final internal temperature of 69.3 degrees C). The DGB system effected a higher, more rapid temperature increase in patties cooked to either target temperature compared to the SSB system. This higher temperature was more effective in destroying pathogens in beef patties. Texture analyses determined that patties cooked on the DGB system had significantly higher values for springiness, adhesiveness, and product height as compared to the SSB system, and patties cooked on either system had significantly higher hardness, gumminess, chewiness, and product height values at the target temperature of 68 degrees C as compared to 60 degrees C.

Identification of optimal ranges in ribeye area for portion cutting of beef steaks

Restaurant-ready (21-d aged, needle tenderized) loin steaks (strip, S; and T-bone, TB) representing three portion sizes (227, 284, and 340 g for S; 397, 454, and 510 g for TB) were portioned from 71 low-Choice beef carcasses representing seven ribeye size groups (70.9 cm2 and less to 103.2 cm2 and greater, in 6.3-cm2 increments). Steaks (n = 568) were cooked on a grooved grill to temperatures of either 67 or 77 degrees C and evaluated for cooking characteristics, sensory attributes (n = 284), and shear force (n = 284) to identify optimal ribeye areas for portioned steaks. As expected, thickness of all portioned steaks decreased (P < .05) as ribeye size increased, whereas thickness of steaks increased (P < .05) as portion size increased. The S were significantly thicker than TB. The TB cooked faster (P < .05) than did S for ribeye areas 77.4 to 83.8 cm2 in the average portion sizes and for ribeye areas 71.0 to 96.6 cm2 in the large portion sizes. However, S cooked significantly faster than did TB for ribeye areas less than 70.9 cm2 in the average portion sizes. The S had higher (P < .05) initial tenderness scores and lower (P < .05) shear values than did TB. Initial tenderness scores were lower (P < .05) for ribeye areas greater than 103.2 cm2 compared with ribeye areas less than 83.8 cm2 and 90.3 to 96.6 cm2, with all others being intermediate. Shear force tended (P = .08) to follow the initial tenderness results. The S cooked to both end point temperatures, and TB cooked to 67 degrees C had higher (P < .05) initial tenderness scores than did TB cooked to 77 degrees C. Tenderness was reduced in TB cooked to higher temperatures as well as in S and TB portioned from ribeye areas greater than 103.2 cm2. Steaks portioned from carcasses with ribeye areas between 77.4 to 96.6 cm2 can optimize both cooking time and tenderness for the foodservice sector.

A pharmaceutical needs assessment in a primary care setting

BACKGROUND

As part of a reconfiguration of its general medical services, Ardach Health Centre has integrated a community pharmacist into the centre to provide pharmaceutical care. In order to systematically identify areas of 'pharmaceutical need', a needs assessment was carried out during October 1997.

AIM

To prioritize and assist the planning of pharmaceutical care provision within the centre, such that maximum gain could be achieved from inevitable limited resources.

METHOD

A four-stage pharmaceutical needs assessment method was created around a selection of techniques: gap analysis, the nominal group technique, and rapid participatory appraisal. This was then applied to a random sample of people drawn from the patient register of Ardach Health Centre and all the health care professionals associated with their care.

RESULTS

Through the four-stage process, a pharmaceutical service priority league table was constructed to reflect the unmet pharmaceutical needs of patients and their primary health care providers. The table provided a structured framework around which pharmaceutical service provision within the health centre could be planned.

CONCLUSION

We have developed a pragmatic, systematic method of identifying the prevalence of unmet pharmaceutical needs of a community. The assessment assisted service selection, balancing what should be done with what could be done and what could be afforded.

Calcium-activated tenderization of strip loin, top sirloin, and top round steaks in diverse genotypes of cattle

Steers of known percentage Brahman (B) and Angus (A) breeding (100% A, n = 6; F1 B x A, n = 6; and 100% B, n = 6) were used to determine the effect of calcium chloride injection on the calpain proteinase system and meat tenderness. The steers were slaughtered in six replications (at either 9 or 14 mm of backfat, determined ultrasonically), with each breed type represented. Calpains and calpastatin activities were measured on fresh, prerigor longissimus muscle samples. Carcass data were collected after a 24-h chill, and the short loin (IMPS #180), top sirloin (IMPS #184), and top round (IMPS #168) were removed from both sides of each carcass. The cuts from the right side were then injected at 5% (wt/wt) with CaCl2 solution (2.2%). Longissimus muscle calpain and calpastatin activities were also measured at 48 h postmortem from the injected and control sides of each carcass. Warner-Bratzler shear force was measured on steaks from the three subprimals aged 1, 2, 5, 15, or 31 d. Marbling scores and USDA quality grades were higher (P<.05) in A than in F1 B x A and B carcasses. Calpastatin activity was higher (P<.05) in muscle from B than in muscle from A and F1 B x A steers, and postmortem storage (O vs 48 h) and CaCl2 injection reduced (P<.05) the activity of the calpains and calpastatin. Strip loin and top sirloin steaks from A and F1 B x A steers were more tender (P<.05) than steaks from B steers; however, top round steak tenderness did not differ (P>.05) across breed type. Calcium injection improved strip loin and top sirloin steak tenderness, but it did not affect top round steak tenderness. Collectively, these data show that CaC12 injection can be used to improve meat tenderness, with similar responses shown in cattle containing 0, 50, and 100% B inheritance. However, even with CaCl2 injection, B steaks are less tender than their A and F1 B x A counterparts.

Effects of DL-malate on ruminal metabolism and performance of cattle fed a high-concentrate diet

To determine the effects of DL-malate on ruminal metabolism, four steers equipped with ruminal cannulas were fed an 80% rolled grain (75% corn:25% wheat) diet twice daily with a DMI equal to 2.0% of BW (485+/-24.8 kg). DL-Malate was infused into the rumen on two consecutive days in 500 mL of phosphate buffer to provide 0, 27, 54, or 80 g of DL-malate/d. Ruminal pH linearly increased (P < .01) with DL-malate concentration and was greater (P < .01) for DL-malate than for the control steers (6.07 vs 5.77). DL-Malate treatment linearly decreased (P < .10) total VFA and tended to linearly increase (P = .10) acetate concentration. Propionate, butyrate, and L-lactate concentrations and acetate:propionate ratio were not affected (P > .10) by DL-malate. Three finishing studies were conducted to determine the effects of feeding DL-malate on growth rate and feed efficiency. In a 98-d experiment, 33 crossbred steers were randomly allotted in a Calan gate feeding system to three DL-malate levels (0, 40, and 80 g/d). Steers (initial weight = 367+/-4.5 kg) were fed a rolled corn-based diet twice daily. After 84 d on feed, gain efficiency (gain:feed) tended to improve with more DL-malate (linear, P < .10) and was 8.1% greater (P < .05) for DL-malate than for the control. The ADG linearly increased (P < .05) with more DL-malate and was 8.6% greater (P = .10) for DL-malate than for the control. After 98-d on feed, ADG was linearly increased (P = .09) by DL--malate, and the greatest increase occurred with 80 g of DL-malate. In the second performance study, 27 Angus steers were randomly allotted in a Calan gate feeding system to three DL-malate concentrations (0, 60, and 120 g/d). Steers (initial weight = 432+/-4.6 kg) were fed diets used in the first finishing study twice daily, but DL-malate was included during the 10-d step-up period. During the 10-d step-up period, feed efficiency and ADG linearly increased (P = .01) with more DL-malate. DL-Malate had little effect on steer and heifer performance or plasma constituents in a 113-d finishing study. Collectively, these results suggest that feeding DL-malate to cattle consuming high-grain diets alleviates subclinical acidosis, and it improved animal performance in two finishing studies.

An evaluation of current and alternative systems for quality grading carcasses of mature slaughter cows

Strip loins from 354 female bovine carcasses, selected to represent 30 skeletal maturity (A, B, C, D, and E) x marbling score (SA/MA/AB, MD, MT, SM, SL, and TR/PD) subclasses, were used to evaluate current and alternative systems for classifying cow carcasses into expected-palatability groups. Strip loins were vacuum-packaged, stored for 14 d postmortem at 2 degrees C, and frozen (-27 degrees C). Five steaks from each strip loin, each cooked to a different internal temperature (60, 66, 71, 77, or 82 degrees C), were used for shear force determinations. Two steaks from each strip loin, one cooked to 66 degrees C and the other to 77 degrees C, were used for sensory evaluation. Increased carcass maturity was associated with decreased tenderness and juiciness, increased flavor intensity, and a higher incidence of flavors described as "painty," "fishy," and "grassy." Position of a carcass within a maturity group had a negligible effect on palatability. Increased marbling was associated with greater tenderness and juiciness, a lower incidence of steaks with a "grassy" flavor, and a higher incidence of steaks with a flavor described as "fatty." Relationships between marbling and beef palatability traits were consistent across all maturity groups. Carcasses of maturities A through E were most effectively stratified according to differences in palatability when marbling scores were grouped as follows: 1) MD and higher; 2) SL, SM, MT; and 3) TR/PD. Among mature (C, D, and E maturity) carcasses, yellow-colored fat was associated with greater beef toughness and higher detection rates for "grassy" and "fishy" flavors. Higher end-point temperatures were associated with higher shear force values and lower ratings for muscle fiber tenderness, connective tissue amount, overall tenderness, and juiciness. Two alternative grading approaches (one involving current quality grading factors and the other involving the use of fat color as an additional grade factor) were developed for possible use in classification of cow carcasses into expected-palatability groups. Both alternative systems provided a more effective stratification of cow carcasses according to palatability differences than did the current USDA quality grading system.

Effective lipid modification by partial ileal bypass reduced long-term coronary heart disease mortality and morbidity: five-year posttrial follow-up report from the POSCH. Program on the Surgical Control of the Hyperlipidemias

BACKGROUND

In 1990, when the Program on the Surgical Control of the Hyperlipidemias (POSCH) reported its in-trial results strongly supporting the conclusion that effective lipid modification reduces progression of atherosclerosis, the differences for the end points of overall mortality and mortality from atherosclerotic coronary heart disease (ACHD) did not reach statistical significance.

METHODS

The Program on the Surgical Control of the Hyperlipidemias recruited men and women with a single documented myocardial infarction between the ages of 30 and 64 years who had a plasma cholesterol level higher than 5.69 mmol/L (220 mg/dL) or higher than 5.17 mmol/L (200 mg/dL) if the low-density lipoprotein cholesterol level was in excess of 3.62 mmol/L (140 mg/dL). Between 1975 and 1983, 838 patients were randomized: 417 to the diet control group and 421 to the diet plus partial ileal bypass intervention group. Mean patient follow-up for this 5-year posttrial report was 14.7 years (range, 12.2-20 years).

RESULTS

At 5 years after the trial, statistical significance was obtained for differences in overall mortality (P = .049) and mortality from ACHD (P = .03). Other POSCH end points included overall mortality (left ventricular ejection fraction > or =50%) (P = .01), mortality from ACHD (left ventricular ejection fraction > or =50%) (P = .05), mortality from ACHD and confirmed nonfatal myocardial infarction (P<.001), confirmed nonfatal myocardial infarction (P<.001), mortality from ACHD, confirmed and suspected myocardial infarction and unstable angina (P<.001), incidence of coronary artery bypass grafting or percutaneous transluminal coronary angioplasty (P<.001), and onset of clinical peripheral vascular disease (P = .02). There were no statistically significant differences between groups for cerebrovascular events, mortality from non-ACHD, and cancer. All POSCH patients have been available for follow-up.

CONCLUSION

At 5 years after the trial, all POSCH mortality and atherosclerosis end points, including overall mortality and mortality from ACHD, demonstrated statistically significant differences between the study groups.

Myocardial infarction and percent arteriographic stenosis of culprit lesion: report from the Program on the Surgical Control of the Hyperlipidemias (POSCH)

The objective of this study was to assess the percent stenosis of the culprit lesion responsible for subsequent myocardial infarction in the Program on the Surgical Control of the Hyperlipidemias (POSCH). It is unknown if the susceptible coronary artery culprit lesion responsible for an acute myocardial infarction is relatively large ( > or = 50% arteriographic stenosis) and hemodynamically significant ( > or = 70% stenosis), or small ( < 50%, stenosis) and asymptomatic. Certain necropsy and arteriography studies support the large progenitor lesion concept, and other arteriography studies support the small lesion hypothesis. We analyzed the coronary arteriogram immediately preceding a Q wave (transmural) myocardial infarction for the degree of stenosis of the suspected culprit lesion, which was selected by visual inspection of the coronary circulation supplying the electrocardiogram-defined area of myocardial infarction. There was no perceptible difference with respect to vessel segment distribution of culprit lesions or time to infarction between the 52 control-group patients and the 27 intervention-group patients. For the two groups combined (n=79), the predominantly involved segments were the middle right coronary artery and the proximal left anterior descending coronary artery. The time interval from the preceding coronary arteriogram closest to the index myocardial infarction ranged from 0 days to 10 years; however, 64.6% of the arteriograms were performed 2 years or less prior to the myocardial infarction. Only 5.1% of the patients in both groups combined had a culprit lesion stenosis < 50%, while 88.6% of the patients in both groups combined had a culprit lesion stenosis > or = 70%. The results strongly favor the large lesion hypothesis of causation for myocardial infarction. It is premature, however, to state that the relative size of the culprit lesion has been indisputably determined. The resolution of this problem has exceedingly important practical implications for the management of patients with known atherosclerotic coronary heart disease and for those asymptomatic individuals with silent atherosclerotic coronary heart disease.