Human lower leg muscles grow asynchronously

Muscle volume must increase substantially during childhood growth to generate the power required to propel the growing body. One unresolved but fundamental question about childhood muscle growth is whether muscles grow at equal rates; that is, if muscles grow in synchrony with each other. In this study, we used magnetic resonance imaging (MRI) and advances in artificial intelligence methods (deep learning) for medical image segmentation to investigate whether human lower leg muscles grow in synchrony. Muscle volumes were measured in 10 lower leg muscles in 208 typically developing children (eight infants aged less than 3 months and 200 children aged 5 to 15 years). We tested the hypothesis that human lower leg muscles grow synchronously by investigating whether the volume of individual lower leg muscles, expressed as a proportion of total lower leg muscle volume, remains constant with age. There were substantial age-related changes in the relative volume of most muscles in both boys and girls (p < 0.001). This was most evident between birth and five years of age but was still evident after five years. The medial gastrocnemius and soleus muscles, the largest muscles in infancy, grew faster than other muscles in the first five years. The findings demonstrate that muscles in the human lower leg grow asynchronously. This finding may assist early detection of atypical growth and allow targeted muscle-specific interventions to improve the quality of life, particularly for children with neuromotor conditions such as cerebral palsy.

Living with Loss: study protocol for a randomized controlled trial evaluating an internet-based perinatal bereavement program for parents following stillbirth and neonatal death

BACKGROUND

Stillbirth and neonatal death are devastating pregnancy outcomes with long-lasting psychosocial consequences for parents and families, and wide-ranging economic impacts on health systems and society. It is essential that parents and families have access to appropriate support, yet services are often limited. Internet-based programs may provide another option of psychosocial support for parents following the death of a baby. We aim to evaluate the efficacy and acceptability of a self-guided internet-based perinatal bereavement support program "Living with Loss" (LWL) in reducing psychological distress and improving the wellbeing of parents following stillbirth or neonatal death.

METHODS

This trial is a two-arm parallel group randomized controlled trial comparing the intervention arm (LWL) with a care as usual control arm (CAU). We anticipate recruiting 150 women and men across Australia who have experienced a stillbirth or neonatal death in the past 2 years. Participants randomized to the LWL group will receive the six-module internet-based program over 8 weeks including automated email notifications and reminders. Baseline, post-intervention, and 3-month follow-up assessments will be conducted to assess primary and secondary outcomes for both arms. The primary outcome will be the change in Kessler Psychological Distress Scale (K10) scores from baseline to 3-month follow-up. Secondary outcomes include perinatal grief, anxiety, depression, quality of life, program satisfaction and acceptability, and cost-effectiveness. Analysis will use intention-to-treat linear mixed models to examine psychological distress symptom scores at 3-month follow-up. Subgroup analyses by severity of symptoms at baseline will be undertaken.

DISCUSSION

The LWL program aims to provide an evidence-based accessible and flexible support option for bereaved parents following stillbirth or neonatal death. This may be particularly useful for parents and healthcare professionals residing in rural regions where services and supports are limited. This RCT seeks to provide evidence of the efficacy, acceptability, and cost-effectiveness of the LWL program and contribute to our understanding of the role digital services may play in addressing the gap in the availability of specific bereavement support resources for parents following the death of a baby, particularly for men.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry, ACTRN12621000631808 . Registered prospectively on 27 May 2021.

Intramuscular fat in children with unilateral cerebral palsy

BACKGROUND

Many children with cerebral palsy develop muscle contractures. The mechanisms of contracture are not well understood. We investigated the possibility that, because fat is stiffer than passive muscle, elevated intramuscular fat contributes to contracture. In this cross-sectional study, we compared the quantity and distribution of intramuscular fat in muscles from typically developing children and children with cerebral palsy who have contractures.

METHODS

mDixon magnetic resonance images were obtained from the legs of 20 ambulant children with unilateral spastic cerebral palsy who had ankle contractures (mean age 11 SD 3 years, 13 male, mean moderate level contracture) and 20 typically developing children (mean age 11 SD 4 years, 13 male). The images were analyzed to quantify the intramuscular fat fraction of the medial gastrocnemius muscles. The amount and distribution of intramuscular fat were compared between muscles of children with cerebral palsy and typically developing children.

FINDINGS

In typically developing children, the medial gastrocnemius muscles had a mean intramuscular fat fraction of 4.7% (SD 1.6%). In children with cerebral palsy, the mean intramuscular fat fractions in the more- and less-affected medial gastrocnemius muscle were 11.4% (8.1%) and 6.9% (3.4%) respectively. There were small but statistically significant regional differences in the distribution of intramuscular fat. There was no evidence of a relationship between intramuscular fat fraction and severity of contracture.

INTERPRETATION

Children with cerebral palsy have higher proportions of intramuscular fat than typically developing children. There is no clear relationship between intramuscular fat fraction and dorsiflexion range of motion in children with cerebral palsy.

Muscle architecture in children with cerebral palsy and ankle contractures: an investigation using diffusion tensor imaging

BACKGROUND

Children with cerebral palsy frequently have ankle contractures which may be caused by changes in architecture of calf muscles. Here, we compared the architecture of medial gastrocnemius muscles in children with unilateral cerebral palsy and typically developing children using novel imaging techniques.

METHODS AND PROCEDURES

Muscle volumes, fascicle lengths, pennation angles and physiological cross-sectional areas were measured from diffusion tensor images and mDixon scans obtained from 20 ambulant children with unilateral spastic cerebral palsy who had ankle contractures (age 11 ± 3 years; mean ± standard deviation) and 20 typically developing children (11 ± 4 years).

FINDINGS

In children with cerebral palsy, the more-affected side had, on average, 13° less dorsiflexion range and the medial gastrocnemius muscle had 4.9 mm shorter fascicles, 50 cm³ smaller volume and 9.5 cm² smaller physiological cross-sectional area than the less-affected side. Compared to typically developing children, the more-affected side had 10° less dorsiflexion range and the medial gastrocnemius muscle had 4.2 mm shorter fascicles, 51 cm³ smaller volume and 10 cm² smaller physiological cross-sectional area. We did not detect differences between the less-affected and typically developing legs.

INTERPRETATION

Three-dimensional measurement of whole medial gastrocnemius muscles confirmed that the architecture of muscles on the more-affected side of children with cerebral palsy differs from the less-affected side and from muscles of typically developing children. Reductions in fascicle length, muscle volume and physiological cross-sectional area may contribute to muscle contracture.

Electrical Stimulation Following Botulinum Toxin A in Children With Spastic Diplegia: A Within-Participant Randomized Pilot Study

AIMS

To determine whether electrical stimulation (ES) following botulinum toxin A (BoNT/A) injection increases passive extensibility of the hamstring muscles in children with spastic diplegia.

METHODS

Six children undergoing bilateral BoNT/A injections to the hamstrings participated in this within-participant single blind randomized controlled trial. One leg of each child was randomised to the experimental condition and the other to the control condition. The experimental leg received daily stretch and ES to the hamstrings for 12 weeks, while the control leg received only daily stretch. The primary outcome was passive hamstring extensibility reflected by popliteal angle measured with a standardised torque. Secondary outcomes were two goniometric measures of popliteal angle using the Modified Tardieu Scale (R1 and R2), and parents' perceptions of treatment effectiveness. Outcomes were measured at baseline, 4 weeks, 12 weeks and 6 months.

RESULTS

The mean between-group difference (95% CI) at 4 weeks was 2° (-2 to 5) for popliteal angle measured with a standardised torque, favouring the experimental leg. Tardieu results for R1 and R2 were 0° (-4 to 3) and 7° (0 to 14), respectively.

CONCLUSION

ES does not improve passive extensibility of the hamstring muscles at 4 weeks over any possible effects of BoNT/A alone.

Delayed post-surgical sepsis from Teflon felt: The diagnostic value of CT scanning, and a reminder for theatre staff

We report on 2 patients with surgical site infections following the inadvertent use of Teflon felt for haemostasis in elective and emergency surgery. CT scanning was superior to plain radiography in demonstrating the foreign bodies to enable planning of further surgical treatment.

14th International HLA and Immunogenetics Workshop: report of progress in methodology, data collection, and analyses

The Biostatistics Component of the 13th International Histocompatibility Workshop (IHWS) developed the PyPop (Python for Population Genomics) software framework for high-throughput analysis and quality control (QC) assessments of highly polymorphic genotype data. Since its initial release, the software has had several new analysis modules added to it. These additions, combined with improved data filtering and QC modules, facilitate analyses of data at different levels (allele, haplotype, amino acid sequence, and nucleotide sequence). Since the 13th IHWS, much of the human leukocyte antigen (HLA) data from the workshop, QCed via PyPop and other methods, have been made publicly available through the Major Histocompatibility Complex database web site at the National Center for Biotechnology Information (http://ncbi.nih.gov/mhc/). The Anthropology/Human Genetic Diversity component (AHGDC) data have been used in a variety of studies. Prugnolle et al. used this data to corroborate a model of pathogen-driven selection as a factor related to high levels of diversity at HLA loci. Using a comparative genomics approach contrasting results for HLA and non-HLA markers, Meyer et al. analyzed a subset of the 13th IHWS AHGDC data and showed that HLA loci show detectable signs of both natural selection and the demographic history of populations.

HLA-A, -B, -C, -DRB1 allele and haplotype frequencies in an African American population

Sequence-based typing was used to identify human leukocyte antigen (HLA)-A, -B, -C, and -DRB1 alleles from 564 consecutively recruited African American volunteers for an unrelated hematopoietic stem cell registry. The number of known alleles identified at each locus was 42 for HLA-A, HLA-B 67, HLA-C 33, and HLA-DRB1 44. Six novel alleles (A*260104, A*7411, Cw*0813, Cw*1608, Cw*1704, and DRB1*130502) not observed in the initial sequence-specific oligonucleotide probe testing were characterized. The action of balancing selection, shaping more 'even' than expected allele frequency distributions, was inferred for all four loci and significantly so for the HLA-A and DRB1 loci. Two-, three-, and four-locus haplotypes were estimated using the expectation maximization algorithm. Comparisons with other populations from Africa and Europe suggest that the degree of European admixture in the African American population described here is lower than that in other African American populations previously reported, although HLA-A:B haplotype frequencies similar to those in previous studies of African American individuals were also noted.

Differentiation between African populations is evidenced by the diversity of alleles and haplotypes of HLA class I loci

The allelic and haplotypic diversity of the HLA-A, HLA-B, and HLA-C loci was investigated in 852 subjects from five sub-Saharan populations from Kenya (Nandi and Luo), Mali (Dogon), Uganda, and Zambia. Distributions of genotypes at all loci and in all populations fit Hardy-Weinberg equilibrium expectations. There was not a single allele predominant at any of the loci in these populations, with the exception of A*3002 [allele frequency (AF) = 0.233] in Zambians and Cw*1601 (AF = 0.283) in Malians. This distribution was consistent with balancing selection for all class I loci in all populations, which was evidenced by the homozygosity F statistic that was less than that expected under neutrality. Only in the A locus in Zambians and the C locus in Malians, the AF distribution was very close to neutrality expectations. There were six instances in which there were significant deviations of allele distributions from neutrality in the direction of balancing selection. All allelic lineages from each of the class I loci were found in all the African populations. Several alleles of these loci have intermediate frequencies (AF = 0.020-0.150) and seem to appear only in the African populations. Most of these alleles are widely distributed in the African continent and their origin may predate the separation of linguistic groups. In contrast to native American and other populations, the African populations do not seem to show extensive allelic diversification within lineages, with the exception of the groups of alleles A*02, A*30, B*57, and B*58. The alleles of human leukocyte antigen (HLA)-B are in strong linkage disequilibrium (LD) with alleles of the C locus, and the sets of B/C haplotypes are found in several populations. The associations between A alleles with C-blocks are weaker, and only a few A/B/C haplotypes (A*0201-B*4501-Cw*1601; A*2301-B*1503-Cw*0202; A*7401-B* 1503-Cw*0202; A*2902-B*4201-Cw*1701; A*3001-B*4201-Cw*1701; and A*3601-B*5301-Cw*0401) are found in multiple populations with intermediate frequencies [haplotype frequency (HF) = 0.010-0.100]. The strength of the LD associations between alleles of HLA-A and HLA-B loci and those of HLA-B and HLA-C loci was on average of the same or higher magnitude as those observed in other non-African populations for the same pairs of loci. Comparison of the genetic distances measured by the distribution of alleles at the HLA class I loci in the sub-Saharan populations included in this and other studies indicate that the Luo population from western Kenya has the closest distance with virtually all sub-Saharan population so far studied for HLA-A, a finding consistent with the putative origin of modern humans in East Africa. In all African populations, the genetic distances between each other are greater than those observed between European populations. The remarkable current allelic and haplotypic diversity in the HLA system as well as their variable distribution in different sub-Saharan populations is probably the result of evolutionary forces and environments that have acted on each individual population or in their ancestors. In this regard, the genetic diversity of the HLA system in African populations poses practical challenges for the design of T-cell vaccines and for the transplantation medical community to find HLA-matched unrelated donors for patients in need of an allogeneic transplant.

Hip displacement in spastic cerebral palsy: repeatability of radiologic measurement

Radiologic measures of migration percentage (MP) and acetabular index (AI) taken from plain radiographs of the pelvis are the most commonly used tools for determining hip displacement and management options in children with cerebral palsy and spastic hip disease. This study determined interrater and intrarater reliability of MP and AI on pelvic radiographs chosen to represent a wide range of age (11 months to 8 years 5 months), MP (0%-56%), and AI (9 degrees -33 degrees ). The study demonstrated that an experienced rater would be expected to measure MP on a single radiograph to within +/-5.8% of the true value and a change in MP between two radiographs taken at different times to within +/-8.3% of the true value. Similarly for AI, the measurement error for a typical rater would be within +/-2.6 degrees on a single reading and +/-3.7 degrees if recording change between two occasions. The authors believe that the results indicating true change are acceptable in clinical practice, provided treatment decisions are based on a series of radiographs taken at 6-month intervals, methods and training are standardized, and consistent raters are used.

Developing a suicide prevention strategy based on the perspectives of people with brain injuries

OBJECTIVE

To develop a service-relevant, suicide prevention strategy based on the perspectives of people with brain injuries and their family members.

DESIGN

Structured interview-based, qualitative case design.

SETTING

Interviews were conducted in the context of community-based brain injury rehabilitation service delivery.

PARTICIPANTS

Ten persons with moderate to severe brain injuries who exhibited suicidal orientations and four family member/carers of these participants.

RESULTS

Qualitative analysis of interview transcripts revealed a number of relevant themes. The primary theme was that informal relationships play a key role in preventing suicide. Secondary themes included the potential role of specialist brain injury rehabilitation services in suicide prevention and the need for provision of more information about brain injury to family and friends to promote understanding.

CONCLUSIONS

Some discrepancy was noted between the perspectives of people with brain injuries and family members. The need for multiple strategies to respond to suicide risk was reinforced. Service-relevant resources (suicide risk screen, contract, and brochure) have been developed and included in service delivery.

A nursing career in the Army

This is the first in a series of three career focus articles discussing nursing in the armed forces. The first concentrates on the Army and subsequent issues will describe nursing in the Royal Navy and the Royal Airforce.

Sexual abuse of children. The detection of semen on skin

OBJECTIVE

The detection of semen on the skin of children who present within 72 hours of an episode of sexual assault is critical to medical, forensic, and legal personnel. The Wood's Lamp, a UV light that causes semen to fluoresce, and four forensic laboratory techniques were compared to determine their sensitivity and decline in sensitivity over time.

DESIGN

A descriptive study.

PARTICIPANTS

Eleven adult female volunteers.

MEASUREMENTS/MAIN RESULTS

Semen was placed on the skin of the volunteers. Samples of the dried semen were assessed during a 28-hour period with the Wood's Lamp, microscopy, the acid phosphatase assay, and two assays for the prostatic protein p30 (counterimmunoelectrophoresis and enzyme-linked immunosorbent assay). The intensity of the Wood's Lamp fluorescence of semen diminished dramatically by 28 hours; in contrast, the fluorescence of urine persisted up to 80 hours. Over time, the p30-enzyme-linked immunosorbent assay technique was more sensitive than microscopy, the acid phosphatase assay, and p30-counterimmunoelectrophoresis in detecting semen on skin.

CONCLUSIONS

The Wood's Lamp is not a sensitive screening tool and should be used with caution. To improve the detection of sexual abuse in children, we recommend that the p30-enzyme-linked immunosorbent assay be used because of its potential as a more sensitive assay than those in current clinical use.

Efficacy and tolerability of enalapril and sustained-release verapamil in older patients with mild to moderate essential hypertension

The study involved 113 patients over age 50 years with mild to moderate essential hypertension, randomly assigned to treatment with enalapril (n = 54) or sustained-release verapamil (n = 59). During an eight-week titration period, doses were adjusted to achieve supine diastolic blood pressures (DBP) below 90 mmHg; patients were then given maintenance doses for eight weeks. Mean blood pressures were reduced significantly from 147.7/93.9 mmHg at baseline to 137.7/84.5 mmHg at the end of the maintenance period in the enalapril group and from 155.1/95.1 to 142.4/86.2 mmHg in the verapamil group. In the patients who completed treatment, the mean daily doses required to maintain DBP below 90 mmHg were 9.6 mg of enalapril and 244.9 mg of verapamil. There were 11 treatment failures in the enalapril group and 22 in the verapamil group: eight of the enalapril and 17 of the verapamil patients did not attain goal blood pressures and three and five were withdrawn because of side effects. It is concluded that both enalapril and sustained-release verapamil were generally effective and well tolerated in the treatment of mild to moderate hypertension in the middle-aged and older patients.