Motor skill competence and moderate- and vigorous-intensity physical activity: a linear and non-linear cross-sectional analysis of eight pooled trials

BACKGROUND

Few studies have examined the relationship between motor skill competence and device-measured physical activity in large samples and none have used non-linear modelling. This study assessed the linear and non-linear associations between motor skill competence and physical activity in children using pooled data from eight studies.

METHODS

Cross-sectional ActiGraph accelerometer and motor skills competence data from 988 children (50.8% boys) aged 3-11 years were included. Total, object control and locomotor skill competence were assessed using the Test of Gross Motor Skill Development. Linear mixed models were fitted to examine linear associations between motor skill competence and physical activity. Then, restricted cubic splines models were used to assess potential non-linear relationships. Interactions by sex and age were assessed.

RESULTS

There was evidence of positive linear associations between total skill, and object control and locomotor skills, with moderate- and vigorous-intensity physical activity; however, the associations with total skill competence and object control better fitted a non-linear model. Non-linear models indicated associations were positive but relatively weak in the low to mid ranges of TGMD/object control scores but at high ranges (~ > 70 out of 100/ and ~ 35 out of 50) the association strength increased for both moderate- and vigorous-intensity physical activity. There were sex interactions for locomotor skills only, specifically for vigorous activity with boys having a stronger positive association than girls.

CONCLUSIONS

There appears to be a threshold for object control skill proficiency that children need to reach to enhance their physical activity levels which provides support for a motor skill "proficiency barrier". This provides a tangible benchmark for children to achieve in motor competence programs.

Screening Nitrate in Forages with a Test Strip: Collaborative Study

A collaborative study was conducted for screening nitrate in forages with a commercially available test strip. The method involves extracting a finely ground sample with deionized water. The test strip is dipped in the sample extract. The color of the reaction zone on the test strip changes from white to pink or purple depending on the nitrate concentration in sample extract. The nitrate present in the extract is determined by comparing the color of the test strip to the color scale on the test strip container. Six blind quintuplicates of forage samples were analyzed by 20 collaborators. Nitrate concentrations in forage samples tested ranged from <1000 ppm nitrate to >10 000 ppm nitrate on dry matter basis. Each collaborator was asked to assign each sample to one of the 4 following nitrate concentration ranges: (1) <1000 ppm, (2) 1000 to 5000 ppm, (3)>5000 ppm to 10 000 ppm, and (4) >10 000 ppm. Nineteen of 20 collaborators reported results. Results from 2 laboratories were rejected as outliers by inspection and χ2 test. Sensitivity rates (p+) ranged from 0.965 to 0.998, with standard errors of 0.006 to 0.16. Specificity rates (p−) ranged from 0.991 to 0.997 for the 4 ranges, with standard errors of 0.003 to 0.006. False-positive rates (pf+) ranged from 0.006 to 0.046, with standard errors of 0.006 to 0.025. False-negative rates (pf−) ranged from 0.003 to 0.007, with standard errors of 0.003 to 0.006. Screening nitrate in forages with a test strip has been adopted first action by AOAC INTERNATIONAL.

Venous Thrombosis Following the Use of Intermediate Purity FVIII Concentrate to Treat Patients with Von Willebrand’s Disease

We describe four patients with von Willebrand’s disease (VWD) who experienced venous thrombosis after treatment with an intermediate purity factor VIII (FVIII) concentrate (Haemate P®) was used to cover invasive or surgical procedures. Most patients had additional risk factors for venous thromboembolism (VTE) and it is difficult to be certain of the contribution of the concentrate to the VTE. In view of the recognised association between high factor VIII activity (FVIII:C) levels and VTE there is a physiological basis for this complication and it is important to consider this when administering FVIII containing concentrates to VWD patients.

Hydroxyethyl starch induced acquired von Willebrand's disease

Hydroxyethyl starch (HES) (Hespan, DuPont) is a widely used synthetic volume expander which in standard doses of up to 1.5l in 24 h has no significant effect on coagulation (Munsch et al. 1988). However, the data sheet states that in large volumes HES may alter the coagulation mechanism. We now report a case of HES induced acquired von Willebrand's disease (vWD) in which severe bleeding occurred.

Venous thrombosis following the use of intermediate purity FVIII concentrate to treat patients with von Willebrand's disease

We describe four patients with von Willebrand's disease (VWD) who experienced venous thrombosis after treatment with an intermediate purity factor VIII (FVIII) concentrate (Haemate P3) was used to cover invasive or surgical procedures. Most patients had additional risk factors for venous thromboembolism (VTE) and it is difficult to be certain of the contribution of the concentrate to the VTE. In view of the recognised association between high factor VIII activity (FVIII:C) levels and VTE there is a physiological basis for this complication and it is important to consider this when administering FVIII containing concentrates to VWD patients.

Creation of a novel donor splice site in intron 1 of the factor VIII gene leads to activation of a 191 bp cryptic exon in two haemophilia A patients

We have constructed a confidential U.K. database of haemophilia A mutations and pedigrees by characterizing the gene defect of one index patient in each U.K. family. Mutations were identified by screening all coding regions of the factor VIII (FVIII) mRNA, using solid-phase fluorescent chemical cleavage of mismatch and examining additional non-coding regions of the gene. Here we report two haemophilia A patients (UK 114 FVIII:C 2% and UK 243 FVIII:C < 1%) with an abnormal FVIII mRNA due to an A to G point mutation, 1.4 kb downstream from exon 1 in the FVIII gene. This mutation creates a new donor splice site in intron 1 and leads to insertion of a 191 bp novel exon in the mRNA. Haplotype analysis suggests that the mutation may have originated in a common ancestor of the two patients, who further illustrate how mRNA analysis allows higher efficiency of haemophilia A mutation detection, because their mutation would not have been identified by direct analysis of the factor VIII gene.

Postmortem diagnosis of accidental cocaine intoxication in a dog

Despite an abundance of data on the experimental effects of cocaine in dogs, no detailed reports documenting accidental cocaine exposure in domestic pets have been reported in the veterinary literature. A case of cocaine intoxication is described in a 19-mo-old male catahoula hound in which the diagnosis was confirmed using histopathology, thin-layer chromatography and mass spectrometry. The case was presented as a possible intoxication of unknown etiology. Routine toxicologic screens and characteristic histologic lesions provided evidence for the diagnosis without prior suspicion of cocaine involvement.

Bovine arsenic toxicosis from ingestion of ashed copper-chrome-arsenate treated timber

Arsenic toxicosis is reported in a variety of animal species. It occurs most commonly in cattle and ranks second only to lead as a cause of heavy metal poisoning. We describe a case of arsenic toxicosis attributable to ingestion of ashes from burned posts treated with an arsenic-containing preservative. Burning of the posts concentrated the arsenic and rendered lethal a product normally used around livestock. Lack of normal salt supplementation to the herd was conducive to pica-like behavior and ingestion of toxic ashes. Rapid diagnosis led to removal of the arsenic source and limited losses to 4 cows.

Microcystin toxicosis in cattle due to overgrowth of blue-green algae

Toxicosis due to microcystin-containing blue-green algae has been sporadically reported in a variety of animal species. Most reports of intoxication involve algal blooms during periods of warm temperatures and abundant sunshine in the spring or early summer. A case of blue-green algae toxicosis with lesions attributable to toxins from Microcystis aeruginosa is described in 4 cattle from southern Georgia during November. The case was unusual in that characteristic hepatic necrosis was accompanied by severe mesenteric edema and peritoneal effusion. In addition, weather conditions and location were not expected to be conducive to algal blooms. Rapid diagnosis and identification of the probable source of intoxication allowed the owner to move the herd away from the affected pond. This action limited losses to only the 4 cattle.

Sequence analysis of an HIV-1 isolate which displays unusually high-level AZT resistance in vitro

Multiple mutations in the reverse transcriptase (RT) gene were observed in a drug-resistant isolate of human immunodeficiency virus type 1 (HIV1) from an individual having prolonged (greater than 2 years) zidovudine (AZT) therapy. The virus replicated in PBMC's in the presence of very high concentrations of AZT (125 microM). Drug-sensitive strains were curtailed by 0.01 microM AZT. Eleven defined mutations were observed as compared with published sequences of RT for eight strains of HIV1. Eight of these mutations were found in the domain involved in nucleotide recognition and enzyme function. Only one of the mutations, giving a Thr--Tyr change at amino acid 215, matched those previously ascribed (67, 70, 215, and 219) to the generation of high-level resistance to AZT. Therefore additional amino acid changes may have significance in the emergence of super-resistant viruses.

The toxicologic investigation of a feed grain contaminated with seeds of the plant species Cassia

Feed grain suspected of causing death in a group of pigs was evaluated for toxic potential in chickens. The contaminated grain sorghum mixture was examined visually and contained 3.7% Cassia occidentalis and 1.6% Cassia obtusifolia seeds by weight. Thirty-two chicks were fed a sample of this suspect grain sorghum mixture. Chickens receiving the contaminated grain lost weight rapidly, exhibited clinical signs typical of intoxication with Cassia spp., and by day 16 were severely debilitated. Necropsy and histologic and electron microscopic examinations demonstrated a skeletal and cardiac degenerative myopathy consistent with intoxication by Cassia occidentalis. These toxicologic investigations verified the toxic potential of the contaminated sorghum mixture for chickens, and these comparative observations support prior diagnostic efforts implicating Cassia spp. as a cause of illness in swine.

Determination of Diagnostic Levels of Arsenic in Animal Tissue: Collaborative Study

The method chosen for this collaborative study is a modification of the AOAC method for As residues, 41.009-41.012. The tissue is dry-ashed overnight at 500°C, and then dissolved in dilute HCl. The solution is diluted and an aliquot is reacted with zinc metal to evolve arsine gas. The gas is trapped in AgDDC solution and As is quantitated at 540 nm. Nine collaborating laboratories performed single analyses on 4 blind duplicate pairs of bovine liver samples which were spiked at 0, 4.3, 10.8, or 21.6 mg As/kg liver. A National Bureau of Standards control (SRM 1566 Oyster Tissue, 13.4 ± 1.9 mg As/kg) and a 1000 mg As/L standard were also submitted to the collaborators. Intralaboratory coefficients of variation ranged from 7.7 to 17.8%; interlaboratory coefficients of variation ranged from 10.9 to 19.0%. The method has been adopted official first action.