705 CHARACTERISING OLDER ADULTS’ RISK OF HARM FROM BLOOD-PRESSURE LOWERING MEDICATIONS: A SUB-ANALYSIS FROM THE PRIME STUDY

Introduction

Hypertension is a major risk factor for cardiovascular disease and death. Randomised trials in older adults with relatively few co-morbidities recommend treatment of their hypertension [1]. However, blood-pressure lowering medications increase the risk of medication-related harm (MRH) from adverse drug reactions (ADRs), non-adherence, medication errors and drug–drug interactions. We aimed to identify characteristics associated with MRH in older people on blood-pressure lowering medications.

Method

The PRIME (prospective study to develop a model to stratify the risk of MRH in hospitalized elderly patients in the UK) study investigating the incidence and cost of MRH in 1280 older people in Southern England [2]. Adults ≥65 years were recruited from five teaching hospitals at hospital discharge and followed up for 8-weeks. Telephone interviews with study participants, review of primary care records and hospital readmissions were undertaken to identify MRH. PRIME study participants taking blood-pressure lowering medications, as defined by National Institute for Health and Care Excellence hypertension guidelines [3], were included in this analysis.

Results

Sixty-six percent of the PRIME cohort (n = 841) were taking blood-pressure lowering medications. Patients on four blood-pressure lowering medications were five times more likely to experience MRH compared to those taking just one medication (OR 4.96; 95%CI 1.63-15.13;p = 0.01). Most harm events were serious (80%,n = 123), requiring dose change or treatment cessation. Most MRH cases were potentially preventable (49%,n = 75).

Conclusion

MRH from blood-pressure lowering medication in older people is common, serious, and potentially preventable. Decisions around maximising cardiovascular risk reduction must be carefully considered in the context of MRH from blood-pressure lowering medications.

References

1. Sheppard JP, Lown M, Burt J et al. Generalizability of blood pressure lowering trials to older patients: cross-sectional analysis. J Am Geriatr Soc 2020; 68: 2508–15.

2. Parekh N, Ali K, Stevenson JM et al. Incidence and cost of medication harm in older adults following hospital discharge: a multicentre prospective study in the UK. Br J Clin Pharmacol 2018; 84: 1789–97.

3. National Institute for Health and Care Excellence (2019). Available at https://www.nice.org.uk/guidance/ng136. Accessed 27/11/2020.

Sex-based differences in lifting technique under increasing load conditions: A principal component analysis

The objective of the present study was to determine if there is a sex-based difference in lifting technique across increasing-load conditions. Eleven male and 14 female participants (n = 25) with no previous history of low back disorder participated in the study. Participants completed freestyle, symmetric lifts of a box with handles from the floor to a table positioned at 50% of their height for five trials under three load conditions (10%, 20%, and 30% of their individual maximum isometric back strength). Joint kinematic data for the ankle, knee, hip, and lumbar and thoracic spine were collected using a two-camera Optotrak motion capture system. Joint angles were calculated using a three-dimensional Euler rotation sequence. Principal component analysis (PCA) and single component reconstruction were applied to assess differences in lifting technique across the entire waveforms. Thirty-two PCs were retained from the five joints and three axes in accordance with the 90% trace criterion. Repeated-measures ANOVA with a mixed design revealed no significant effect of sex for any of the PCs. This is contrary to previous research that used discrete points on the lifting curve to analyze sex-based differences, but agrees with more recent research using more complex analysis techniques. There was a significant effect of load on lifting technique for five PCs of the lower limb (PC1 of ankle flexion, knee flexion, and knee adduction, as well as PC2 and PC3 of hip flexion) (p < 0.005). However, there was no significant effect of load on the thoracic and lumbar spine. It was concluded that when load is standardized to individual back strength characteristics, males and females adopted a similar lifting technique. In addition, as load increased male and female participants changed their lifting technique in a similar manner.

Ertapenem clearance during modeled continuous renal replacement therapy

PURPOSE

To determine ertapenem transmembrane clearance (CLtm) during continuous renal replacement therapy (CRRT) using a validated in vitro model.

METHODS

Ertapenem clearance during continuous hemofiltration and hemodialysis was assessed with AN69 and polysulfone hemodiafilters at 4 dialysate (Qd) and ultrafiltration rates (Quf): 1, 2, 3, and 6 l/hour. Blood and dialysate samples were collected at each flow rate and assayed for urea (control solute) and ertapenem concentrations. The experiment was repeated 5 times for each hemodiafilter type. Ertapenem and urea sieving coefficient (SC) and saturation coefficient (SA) were assessed, and CLtm calculated.

RESULTS

In continuous hemofiltration mode, urea and ertapenem SC ranged from 1.00 to 1.19 at all Quf and did not differ between hemodiafilter types. Consequently, convective CLtm also did not differ between hemodiafilters. In continuous dialysis mode, urea Cltm did not differ between hemodiafilter types at any Qd. However, ertapenem SA and CLtm were significantly different between hemodiafilter types at Qd 6l/hour (p<0.001). As Qd increased, mean +/- SD AN69 SA declined significantly from 0.87 +/- 0.12 at Qd 1 l/hour to 0.45 +/- 0.02 at Qd 6 l/hour (p<0.001). Ertapenem SA did not differ at any Qd with the polysulfone hemodiafilter (range 0.71-0.80).

CONCLUSION

Ertapenem was cleared substantially in these in vitro CRRT models. However, our findings illustrate discordance between our observed SC and SA and the published unbound fraction of ertapenem. This finding has been reported with many other drugs, including carbapenem antibiotics. If in vivo studies corroborate our SA and SC findings, dosage adjustment for patients receiving CRRT will be required.

Biomechanical assessment of lateral stiffness elements in the suspension system of a backpack

The purpose of this study was to examine the change in load distribution characteristics associated with adding lateral stiffness elements (rods) to a rucksack (backpack). A load distribution mannequin was instrumented with two 3D load cells to allow determination of the load applied to the shoulders and upper torso independent of the load applied to the hips and lower trunk. Position and mass of the payload (25 kg) were fixed at the centre of the volume of the rucksack and held constant during all testing. It was hypothesized that lateral rods would provide a force bridge that transfers part of the vertical load of the pack from the upper back and shoulders to the hip belt thereby reducing the vertical load on the torso, and possibly reducing the horizontal reaction force that produces a shear load on the spine. Results showed that these active stiffness elements shifted 14% of the vertical load from the upper torso to the pelvic region with lumbar shear load remaining relatively unchanged for all combinations of shoulder strap and waist belt tension. The lateral rods also provided a mean increase of 12% in the extensor moment at the L3-L4 level, thus reducing some demand on the erector spinae muscles.

A suite of objective biomechanical measurement tools for personal load carriage system assessment

For application to military and civilian needs, Defence Research and Development Canada--Toronto contracted Queen's University, Kingston to develop a suite of biomechanical assessment and analytical tools to supplement human-based load carriage system assessment methods. This suite of tools permitted efficient objective evaluation of biomechanical aspects of load-bearing webbing, vests, packs and their components, and therefore contributed to early system assessment and a rapid iterative design process. This paper is a summary of five assessment and analytical tools. A dynamic load carriage simulator was developed to simulate cadence of walking, jogging and running. The simulator comprised a computer-controlled pneumatic platform that oscillated anthropometrically weighted mannequins of varying dimensions from which measures of skin contact pressure, hip reaction forces and moments and relative pack-person displacements were taken. A stiffness tester for range of motion provided force-displacement data on pack suspension systems. A biomechanical model was used to determine forces and moments on the shoulders and hips, and validated using a static load distribution mannequin. Subjective perceptual rating systems were used gather soldier feedback during a standardized mobility circuit. Objective outcome measures were validated by means of other objective measures (e.g., Optotrak, video, Instron, etc.) and then compared to subjective ratings. This approach led to development of objective performance criteria for load carriage systems and to improvements in load carriage designs that could be used both in the military and in general.

Optimizing Load Carriage Systems

Biomechanical assessment tools provide designers with quick feedback on design and human comfort tolerances of backpacks.

Impact of multiple injections on immunization rates among vulnerable children

BACKGROUND

In 1997, the Advisory Committee on Immunization Practices (ACIP) recommended a switch from oral polio vaccine (OPV) to inactivated polio vaccine (IPV) for the first two infant doses. The ACIP also recommended use of diphtheria, tetanus, and acellular pertussis vaccine (DTaP) for infants. These recommendations resulted in two additional injections at the 2- and 4-month immunization visits. This study evaluates the implementation of new IPV and DTaP immunization recommendations and their impact on immunization coverage levels.

METHODS

Immunization coverage was assessed in public clinics in three urban areas before and after the recommendations. One pre- and three post-recommendation cohorts were followed to 12 months of age.

RESULTS

Almost all (> or = 88%) infants in the pre-recommendation cohort received OPV, DTP, and only one or two injections. Almost all (> or = 78%) infants in the post-recommendation cohorts received IPV, DTaP, and three or four injections. The percentage of infants in the post-recommendation cohorts up-to-date for immunizations at 12 months of age was slightly higher than those in the pre-recommendation cohort.

CONCLUSIONS

Providers rapidly switched from OPV and DTP to IPV and DTaP. Coverage at 12 months of age was higher among IPV/DTaP recipients than among OPV/DTP recipients. Provider and parent acceptance of four injections at a visit was high. The recent pneumococcal conjugate vaccine recommendations potentially add a fifth injection at 2 and 4 months of age. Acceptance or rejection of five injections by providers and parents needs early assessment.

Binding site elucidation of hydantoin-based antagonists of LFA-1 using multidisciplinary technologies: evidence for the allosteric inhibition of a protein--protein interaction

The binding site on the lymphocyte function-associated antigen-1 (LFA-1) of a class of hydantoin-based antagonists of leukocyte cell adhesion has been identified. This site resides in the inserted-domain (I-domain) of the CD11a chain at a location that is distal to residues known to be required for interactions with the intercellular adhesion molecules. This finding supports the hypothesis that the molecules are antagonizing cell adhesion via an allosteric modification of LFA-1. The binding site was identified using an integrated immunochemical, chemical, and molecular modeling approach. Antibodies that map to epitopes on the I-domain were blocked from binding to the purified protein by the hydantoins, indicating that the hydantoin-binding site resides on the I-domain. Photoaffinity labeling of the I-domain followed by LC/MS and LC/MS/MS analysis of the enzymatic digest identified proline 281 as the primary amino acid residue covalently attached to the photoprobe. Distance constraints derived from this study coupled with known SAR considerations allowed for the construction of a molecular model of the I-domain/inhibitor complex. The atomic details of the protein/antagonist interaction were accurately predicted by this model, as subsequently confirmed by the X-ray crystal structure of the complex.

A longitudinal study of the development of low back pain in an industrial population

STUDY DESIGN

This is a longitudinal study in which industrial workers without chronic low back pain (LBP) were initially assessed with a comprehensive test battery and surveyed every 6 months thereafter for 2 years.

OBJECTIVE

To determine factors that may predispose industrial workers who lift over 5000 kg per shift to LBP.

SUMMARY OF BACKGROUND DATA

Prospective studies are small in number and often limited in breadth or depth of the test battery, methodologic issues, or investigator expertise. There are no prospective studies that focus on a homogeneous work sample of industrial employees.

METHODS

Production workers (n = 149) who volunteered for the 2-year study were assessed using physical measures (e.g., muscular strength, endurance, and flexibility), lifting kinematics (a sagittal plane box lift), and health, lifestyle, and work environment data (paper questionnaires). Follow-up questionnaires were distributed every 6 months for 2 years.

RESULTS

Using self-report of LBP as the main outcome measure, eight variables predicted LBP in this sample with a 75% correct prediction rate. Predictor variables included age, thoracic acceleration during the trunk velocity test, median frequency intercept of electromyography of the right L3 erector spinae, quadriceps strength, quadriceps endurance, self-assessment of fitness, having a confidante, and number of medications currently taken.

CONCLUSION

Results confirmed the multifactorial nature of low back pain and suggest that personal fitness is an important defense against low back pain, even in manual handling lifting tasks.

Back fitness and back health assessment considerations for the Canadian Physical Activity, Fitness and Lifestyle Appraisal

The Canadian Physical Activity, Fitness, and Lifestyle Appraisal (CPAFLA) is used as a measure for the health-related fitness of the general population. The CPAFLA includes an evaluation of back health, which is comprised of abdominal muscular endurance (partial curl-ups) and trunk flexion (sit and reach). This paper reviews the occupational, lifestyle, and physical risks associated with back pain and examines the measurement techniques used to assess health-related fitness components of back health in fitness assessments, such as the CPAFLA. Recommendations for future revisions of the CPACFLA's back health assessment and future research needs are presented.

Vaccination status of children in the Women, Infants, and Children (WIC) Program: are we doing enough to improve coverage?

BACKGROUND

Vaccination-promoting strategies in the Supplemental Nutrition Program for Women, Infants, and Children (WIC) have been shown to produce dramatic improvements in coverage and other health outcomes.

OBJECTIVES

To determine national and state-specific population-based vaccine coverage rates among preschool children who participate in the WIC program, and to describe the strategies for promoting vaccination in WIC.

DESIGN/METHODS

Demographic data, WIC participation, and vaccination histories for children aged 24 to 35 months in 1999 were collected from parents through the National Immunization Survey. The healthcare providers for the children in the survey were contacted to verify and complete vaccination information. We defined children as up-to-date (UTD) if they had received four doses of diphtheria and tetanus toxoids and pertussis vaccine (DPT), three doses of poliovirus vaccine, one dose of measles-mumps-rubella vaccine (MMR), and three doses of Haemophilus influenzae type b vaccine (Hib) by 24 months. Description of state-level vaccination-promoting activities in WIC was collected through an annual survey completed by the state WIC and immunization program directors.

RESULTS

Complete data were collected on 15,766 children, of whom 7783 (49%) participated in WIC sometime in their lives. Nationally, children who had ever participated in WIC were less well-immunized at 24 months compared to children who had not: 72.9% UTD (95% CI, 71.3-74.5) versus 80.8% UTD (95% CI, 79.5-82.1), respectively. In 42 states, 24-month coverage among WIC participants was less than among non-WIC participants, including 13 states where the difference was > or = 10%. Vaccination activities linked with WIC were reported from 76% of 8287 WIC sites nationwide. States conducting more-frequent interventions and reaching a higher proportion of WIC participants had 40% higher vaccination coverage levels for the WIC participants in that state (p<0.05).

CONCLUSIONS

Children served by WIC remain less well-immunized than the nation's more-affluent children who do not participate in WIC. Thus, WIC remains a good place to target these children. This study provides evidence that fully implemented WIC linkage works to improve vaccination rates. Strategies that have been shown to improve the vaccination coverage levels of WIC participants should be expanded and adequately funded to protect these children.

Performance of US hospitals on recommended screening and immunization practices for pregnant and postpartum women

OBJECTIVE

Recommendations by most national advisory committees on immunization include evaluating all pregnant women for chronic hepatitis B virus infection and immunity to rubella. It is recommended that all pregnant women be screened for hepatitis B surface antigen during an early prenatal visit and that rubella vaccine be administered in the postpartum period to women not known to be immune. This study determined the extent to which hospitals with labor and delivery services adhere to these recommendations.

METHODS

We conducted a mail survey of a stratified random sample of all US medical-surgical hospitals to (1) determine the proportion of hospitals with hepatitis B screening policies and rubella immunization programs and (2) identify significant factors associated with the presence of these policies and programs. Hospitals were stratified by number of beds (<100, 100-499, and > or =500) and affiliation with a medical school.

RESULTS

Of 986 institutions surveyed, 858 (87%) responded. Of these, 635 (74%) were labor and delivery hospitals. Approximately half of these (51%) had hospital policies related to screening pregnant women for the hepatitis B surface antigen. Twenty-one percent had rubella immunization programs for postpartum women. Only 14% of labor and delivery hospitals were in full compliance with published recommendations for hepatitis B surface antigen screening and rubella postpartum vaccination. Hospitals were more likely to be compliant if they had more than 100 beds, were private rather than public institutions, were affiliated with a medical school, and were in states with laws regarding hepatitis B surface antigen screening of pregnant women.

CONCLUSIONS

Almost half, and more than three quarters, of hospitals were not in compliance with hepatitis B screening and rubella postpartum immunization recommendations, respectively. Hospitals should develop and implement policies for these preventive services.

Inositol signaling and plant growth

Living organisms have evolved to contain a wide variety of receptors and signaling pathways that are essential for their survival in a changing environment. Of these, the phosphoinositide pathway is one of the best conserved. The ability of the phosphoinositides to permeate both hydrophobic and hydrophilic environments, and their diverse functions within cells have contributed to their persistence in nature. In eukaryotes, phosphoinositides are essential metabolites as well as labile messengers that regulate cellular physiology while traveling within and between cells. The stereospecificity of the six hydroxyls on the inositol ring provides the basis for the functional diversity of the phosphorylated isomers that, in turn, generate a selective means of intracellular and intercellular communication for coordinating cell growth. Although such complexity presents a difficult challenge for bench scientists, it is ideal for the regulation of cellular functions in living organisms.

Vaccination practices, policies, and management factors associated with high vaccination coverage levels in Georgia public clinics. Georgia Immunization Program Evaluation Team

BACKGROUND

Controlling vaccine-preventable diseases by achieving high childhood vaccination coverage levels is a national priority. However, there are few, if any, comprehensive evaluations of state immunization programs in the United States, and little attention has been given to the importance of vaccination clinic management style and staff motivation.

OBJECTIVE

To evaluate the factors associated with the increase in childhood vaccination coverage levels from 53% in 1988 to 89% in 1994 in Georgia's public health clinics.

DESIGN

A 1994 mail survey obtaining information on clinic vaccination policies and practices and management practices.

SETTING

All 227 public health clinics in Georgia.

PARTICIPANTS

Clinic nurses responsible for vaccination services.

OUTCOME MEASURE

The 1994 clinic-specific coverage level for 21- to 23-month-old children for 4 doses of diphtheria and tetanus toxoids and pertussis vaccine, 3 doses of polio vaccine, and 1 dose of a measles-containing vaccine as determined by an independent state assessment of clinic coverage levels.

RESULTS

Univariate analysis showed that higher coverage levels were significantly (P<.05) associated with smaller clinic size, higher proportions of clientele enrolled in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC), being a nonurban clinic, and numerous vaccination practices and policies. Multivariable analysis showed that only 8 of greater than 150 factors remained associated with higher coverage levels, including having no waiting time to be seen, having telephone reminder systems, conducting home visits for defaulters, and restricting WIC vouchers when a child was undervaccinated. Motivational factors related to higher coverage included clinic lead nurses receiving an incentive to raise coverage and lead nurses participating in assessments of clinic coverage levels by state immunization staff.

CONCLUSIONS

No single factor is responsible for raising vaccination coverage levels. Efforts to improve coverage should include local assessment to provide feedback on performance and identify appropriate local solutions. Coordinating with WIC, conducting recall and reminder activities, motivating clinic staff, and having staff participate in decisions are important in raising vaccination levels.

The first five years: a review of the collaboration between DHHR and the WVU School of Medicine

In 1992, the West Virginia Dept. of Health and Human Resources (DHHR) and the West Virginia University School of Medicine, Dept. of Behavioral Medicine and Psychiatry (BM & P), entered into a collaborative effort to provide treatment for patients at the state-operated psychiatric hospital in Weston, W.Va. Within five years, patients were moved into a new, modern facility renamed the William R. Sharpe Jr. Hospital, which is JCAHO approved and Medicare certified; the clinical and nursing staff has increased by 38%; and students from a variety of disciplines rotate through for training. In addition, 70% of all patients admitted are discharged within 20 days or less.

A phosphatidylinositol 4-kinase pleckstrin homology domain that binds phosphatidylinositol 4-monophosphate

Pleckstrin homology (PH) domains are found in many proteins involved in signal transduction, including the family of large molecular mass phosphatidylinositol (PI) 4-kinases. Although the exact function of these newly discovered domains is unknown, it is recognized that they may influence enzyme regulation by binding different ligands. In this study, the recombinant PI 4-kinase PH domain was explored for its ability to bind to different phospholipids. First, we isolated partial cDNAs of the >7-kilobase transcripts of PI 4-kinases from carrot (DcPI4Kalpha) and Arabidopsis (AtPI4Kalpha). The deduced primary sequences were 41% identical and 68% similar to rat and human PI 4-kinases and contained the telltale lipid kinase unique domain, PH domain, and catalytic domain. Antibodies raised against the expressed lipid kinase unique, PH, and catalytic domains identified a polypeptide of 205 kDa in Arabidopsis microsomes and an F-actin-enriched fraction from carrot cells. The 205-kDa immunoaffinity-purified Arabidopsis protein had PI 4-kinase activity. We have used the expressed PH domain to characterize lipid binding properties. The recombinant PH domain selectively bound to phosphatidylinositol 4-monophosphate (PI-4-P), phosphatidylinositol 4,5-bisphosphate (PI-4,5-P2), and phosphatidic acid and did not bind to the 3-phosphoinositides. The PH domain had the highest affinity for PI-4-P, the product of the reaction. Consideration is given to the potential impact that this has on cytoskeletal organization and the PI signaling pathway in cells that have a high PI-4-P/PI-4,5-P2 ratio.

The influence of muscle fiber size and type distribution on electromyographic measures of back muscle fatigability

STUDY DESIGN

This was a cross-sectional study carried out on a group of 31 healthy, consenting volunteers with no history of low back pain (17 men, 14 women).

OBJECTIVES

To evaluate the relationship between electromyographic measures of erector spinae fatigability and the muscle's fiber type characteristics.

SUMMARY OF BACKGROUND DATA

Using electromyographic techniques, a pronounced fatigability of the muscles of patients with low back pain has been identified. It has been postulated that this is the result of an unfavorable back muscle fiber type distribution, although an association between electromyographic measures of fatigue and the muscle's fiber type characteristics has never been established.

METHODS

Two tests of back extensor fatigability were performed (on separate days), each to the limit of endurance: 1) maintenance of 60% total maximum voluntary contraction of the back extensors, and 2) performance of the Biering-Sørensen test. Pairs of surface electrodes were attached to the skin overlying the belly of the erector spinae, bilaterally, at T10 and L3. The median frequency was computed from the electromyographic power spectrum, and fatigability was given by the slope of the linear regression of median frequency on time (MFgrad; %.s-1). One week later, two percutaneous erector spinae muscle biopsy samples were obtained from the same sites described for electromyography (left side only). Samples were prepared for histochemistry for the identification of muscle fiber types. Fiber sizes (cross-sectional areas) were quantified using computerized image analysis.

RESULTS

The mean fiber size at each erector spinae region showed a significant correlation with maximum back extensor strength. In the thoracic region, the relative area of the muscle occupied by Type I fibers (which accounts for the relative size and distribution of the fiber types) showed a significant relationship with MFgrad recorded during each fatigue test. A similar relationship was observed for the lumbar region, but for the Biering-Sørensen test only.

CONCLUSIONS

The electromyographic changes recorded in back muscles during fatigue appear to be related to the underlying muscle fiber type area distribution. This confirms the usefulness of electromyography in reflecting such muscle characteristics in a noninvasive manner, when monitoring changes in function consequent to the development of, or rehabilitation from, low back pain.

Muscle fibre size and type distribution in thoracic and lumbar regions of erector spinae in healthy subjects without low back pain: normal values and sex differences

This study sought to investigate the normal muscle fibre size and type distribution of the human erector spinae, both in thoracic and lumbar regions, in a group of 31 young healthy male (n = 17) and female (n = 14) volunteers. Two percutaneous muscle biopsy samples were obtained under local anaesthesia, from the belly of the left erector spinae, at the levels of the 10th thoracic and 3rd lumbar vertebrae. Samples were prepared for routine histochemistry for the identification of fibre types. Fibre size (cross-sectional area (CSA) and narrow diameter (ND)) was quantified using computerised image analysis. The mean CSA/ND for each fibre type was greater in the thoracic than the lumbar region, but there was no difference between the 2 regions either for percentage type I (i.e. percentage distribution by number), percentage type I area (i.e. relative area of the muscle occupied by type I fibres) or the ratio describing the size of the type I fibre relative to that of the type II. Men had larger fibres than women, for each fibre type and at both sampling sites. In the men, each fibre type was of a similar mean size, whereas in the women the type I fibres were considerably larger than both the type IIA and type IIB fibres, with no difference between the latter two. In both regions of the erector spinae there was no difference between men and women for the proportion (%) of a given fibre type, but the percentage type I fibre area was significantly higher in the women. The erector spinae display muscle fibre characteristics which are clearly very different from those of other skeletal muscles, and which, with their predominance of relatively large type I (slow twitch) fibres, befit their function as postural muscles. Differences between thoracic and lumbar fascicles of the muscle, and between the muscles of men and women, may reflect adaptive responses to differences in function. In assessing the degree of any pathological change in the muscle of patients with low back pain, it seems clear that (1) sex cannot be disregarded and (2) 'atrophied' (using the criteria from other muscles) type II fibres are not necessarily abnormal for the erector spinae, particularly in women.

Breast cancer in Western Australia in 1989. V: Outcome at 5 years after diagnosis

BACKGROUND

A follow-up study was undertaken of all Western Australian women who had a new diagnosis of breast cancer during 1989. The aims were to determine survival, frequency of recurrence and quality of life (QoL) of Western Australian women 5 years after a diagnosis of breast cancer; to determine reasons for choice or rejection of reconstructive surgery in those women treated by mastectomy, and to determine if the choice of lumpectomy or mastectomy affects subsequent QoL.

METHODS

The vital status as at 1st June 1994 of all 692 women who had a new diagnosis of breast cancer in 1989 was ascertained by electronic linkage to official mortality registrations. A subsample of 215 survivors who had originally been treated by the nine surgeons who had managed 20 or more cases each was sent a reply-paid postal questionnaire asking about follow-up treatment since diagnosis, recurrence of disease, current QoL and attitudes to, and use of, reconstructive surgery.

RESULTS

The overall survival rate at 5 years was 80.8% (85.9% and 78.8% for Stage I and II, respectively). Cumulative mortality was 35% lower among the third of patients treated by the nine most active surgeons (14% vs 22%, P < 0.02), but this may be subject to referral bias. The subsample was representative of all surviving cases except for being an average of 2.7 years younger at diagnosis (mean ages 55.2 and 57.9 years). The response rate of the subsample to the postal questionnaire was 78%. Of women who had had a mastectomy, 40% had considered having a reconstruction, but only nine (11%) had undergone this operation. Median QoL on the Rosser scale (maximum = 1.0) was 0.9. QoL was worse for the 23% of patients with a recurrence of breast cancer. Patients treated by breast-conserving surgery showed a trend toward a better QoL compared with those treated by mastectomy.

CONCLUSION

At 5 years after the diagnosis of breast cancer, one in five women had died and an estimated one in four of the survivors had recurrent disease. Quality of life in the remaining patients, half of whom had undergone adjuvant treatment, was very good. These are important baseline data against which to judge the impact of mammographic screening.

On the nature of Wisconsin Card Sorting Test performance in schizophrenia

Performance on the Wisconsin Card Sorting Test (WCST) is widely reported to be impaired in patients with schizophrenia. It has been hypothesized that the performance deficit on the WCST in schizophrenia is related to a dysfunction of the frontal lobe, specifically the dorsolateral prefrontal cortex. This hypothesis was tested by comparing a group of patients with schizophrenia to patients with low grade right or left frontal lobe tumors and a group of patients with non-frontal high grade tumors. The results demonstrated a remarkable similarity in performance on the WCST between patients with schizophrenia and patients with right frontal lobe tumors. Patients with left frontal lobe tumors, non-frontal tumors, and normal control subjects did not show the same pattern of performance. This study provides support for frontal lobe dysfunction in the symptomatology of schizophrenia.

A model immunization demonstration for preschoolers in an inner-city barrio, San Diego, California, 1992-1994

An immunization demonstration project was conducted in an inner-city Latino neighborhood in San Diego to address underimmunization of children of preschool age. The project attempted interventions on consumer, provider, and system levels to reduce barriers to immunization and raise immunization rates. Free walk-in immunization clinics with emphasis on cultural sensitivity and that incorporated computerized reminder/recall were established. An educational series was offered to community health center (CHC) providers, and extensive community-based outreach and education took place in schools, churches, a WIC site, etc. Evaluation activities included preintervention and postintervention provider knowledge, attitudes, and practice surveys, CHC chart audits, and household surveys in the intervention ZIP code area and a control ZIP code area. Immunization coverage for 4DPT, 3OPV, and 1MMR (4:3:1) among two-year-olds increased significantly from 37% to 50% overall, and to 59% in the 1991 birth cohort in the intervention area compared to a one percentage point overall increase in the control area. Coverage improved significantly and missed opportunities decreased in one intervention CHC that participated most actively in educational inservices. While the Year 2000 U.S. Public Health Service objective of 90% 4:3:1 coverage for two-year-olds was not achieved over the 21-month course of the project, the results approached the 1996 single-antigen objectives. This demonstration underscores the importance of multilevel interventions including low cost, no appointment, and culturally appropriate immunization services for the indigent; the use of computerized reminder systems; and provider assessment, education, and feedback in the effort to raise preschool immunization levels. Medical Subject Headings (MeSH): immunization, preschool-age children, health promotion, provider education, immunization monitoring and follow-up systems, pediatric immunization standards, household surveys.

Gender differences in performance of a selection test using the incremental lifting machine

The purpose of the study was twofold: (1) to examine any gender differences in the performance of a pre-employment selection test using the incremental lifting machine (ILM); and (2) to formulate recommendations regarding analyses of selection fairness in studies of pre-employment screening tests and devices. Data were collected in a series of studies designed to permit analyses of: (1) dynamic measures derived for a 1.8 m maximum ILM strength test; (2) relationships between ILM test scores and performance of a maximal box-lifting task using three different protocols; (3) the impact of anthropom trie measures on performance of both test and task; (4) prediction of actual task performance; and (5) accuracy of the ILM screening test for three different cut-off standards. Results revealed that females differed significantly from males in their performance of a 1.8 m maximum ILM strength test in terms of timing, displacement, velocity, acceleration, force and power. Maximum ILM scores attained by females were poorly correlated with maximum box-lifting scores, but they were significantly related to body weight. Also, regression analyses based on ILM scores and associated dynamic parameters accounted for twice as much variance in box-lifting scores for males than for females. Furthermore, the use of cut-off standards of 22.7 kg and 27.3 kg produced a percentage of false negative results for females (12% and 32% respectively), but not for males. Also, for the cut-off level of 27.3 kg, female selection rates were only 56% of the selection rates for males. Issues for future investigation are recommended.

Vaccine-associated paralytic poliomyelitis in the United States: no evidence of elevated risk after simultaneous intramuscular injections of vaccine

During the past 30 years, Romania reported rates of vaccine-associated paralytic poliomyelitis (VAPP) approximately 10-fold higher than in the United States. The elevated VAPP risk was largely caused by multiple intramuscular (im) injections with antibiotics given within 30 days of onset of paralysis. Because it is not known whether im injections contribute to the VAPP risk in the United States, we examined VAPP cases reported since 1980. We reviewed injection histories of VAPP cases reported to the Centers for Disease Control and Prevention from 1980 to 1993: with vaccines for 1980 to 1987; and for all substances for 1988 to 1993. Rates of VAPP by number of im injections with vaccines were calculated from 1988 to 1993 with estimated vaccine coverage data from the National Health Interview Survey. From 1980 to 1993 a total of 119 cases of poliomyelitis were reported to the Centers for Disease Control and Prevention. Of these, 87 (73%) were vaccine-associated and immunologically normal: 41 were oral polio vaccine (OPV) recipient cases; 40 were OPV contact cases; and 6 were community-acquired cases. A history of im injections in the 45 days before onset of paralysis was obtained from 28 (72%) of 39 recipient cases reported from 1980 to 1993 for which dates of paralysis onset could be determined and from 1 (8%) of 13 contact cases reported from 1988 to 1993. With one exception all substances administered intramuscularly were routine childhood vaccines. No clustering of im injections in the "high risk" windows, 0 to 3 and 8 to 21 days before onset of paralysis, was observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Relative lumbar and pelvic motion during loaded spinal flexion/extension

STUDY DESIGN

This study analyzed relative lumbar and pelvic motion during sagittal plane trunk motion. Patterns of movement were compared during loaded trunk flexion and extension.

OBJECTIVES

The purpose of this study was to examine the dynamic relationship between the lumbar spine and pelvis during trunk motion and to determine the effect of direction of lift (up vs. down) on lumbar-pelvic rhythm.

SUMMARY OF BACKGROUND DATA

There is disagreement in the literature regarding whether rotations of the pelvis and lumbar spine occur sequentially or simultaneously during bending and lifting tasks.

METHODS

Thirty healthy women, ranging in age from 19 to 35 years, participated in the study. The 3Space Tracker System, an electromagnetic tracking device, was used to monitor simultaneous lumbar and pelvic motion as subjects lifted and lowered a 9.5 kg box with knees extended.

RESULTS

Although lumbar and pelvic motion occurred simultaneously during flexion and extension, there was greater separation of these movements during the "up lifts" than during the "down lifts."

CONCLUSIONS

Lumbar-pelvic rhythm varied depending on whether the trunk was flexing or extending. During trunk flexion (down lift) there was a greater tendency for lumbar and pelvic rotations to occur simultaneously, whereas during extension (up life) they tended to occur more sequentially.

High-performance liquid chromatography and photoaffinity crosslinking to explore the binding environment of nevirapine to reverse transcriptase of human immunodeficiency virus

Nevirapine (BI-RG-587) is a potent inhibitor of the polymerase activity of reverse transcriptase of human immunodeficiency virus type-1. Nevirapine, as well as several other non-nucleoside compounds of various structural classes, bind strongly at a site which includes tyrosines 181 and 188 of the p66 subunit of reverse transcriptase. The chromatography which was utilized to explore this binding site is described. BI-RH-448 and BI-RJ-70, two tritiated photoaffinity azido analogues of nevirapine, are each crosslinked to reverse transcriptase. The use of several HPLC-based techniques employing different modes of detection makes it possible to demonstrate a dramatic difference between the two azido analogues in crosslinking behavior. In particular, by comparing HPLC tryptic peptide maps of the photoadducts formed between reverse transcriptase and each azido analogue, it can be shown that crosslinking with BI-RJ-70 but not with BI-RH-448 is more localized, stable, and hence exploitable for the identification of the specifically bonded amino acid residue(s). In addition, comparison of the tryptic maps also makes it feasible to assess which rings of the nevirapine structure are proximal or distal to amino acid side chains of reverse transcriptase. Finally, another feature of the HPLC peptide maps is the application of on-line detection by second order derivative UV absorbance spectroscopy to identify the crosslinked amino acid residue.

The use of the Nordic questionnaire in an industrial setting: a case study

The aims of this study were to identify: (1) whether patterns of reported injury are differentially affected by the structure of the interview and qualifications of the interviewer; and (2) whether the Nordic Questionnaire is sensitive enough to identify different patterns of reported injuries across two different workstations. To accomplish this the Standardized Nordic Questionnaire was administered by both a physiotherapist and an ergonomist to two similar but separate workstations of a manufacturing plant. Analysis of the injury-reporting frequencies produced results indicating increased reporting to the ergonomist in two of five upper limb and trunk body regions considered at one workstation and in one region at the other. Differences in reporting frequencies between workstations were also found. Physical demands analyses performed in each area confirmed that differing job requirements existed in the two workstations under consideration. Early identification of potential job-specific injuries by an in-house ergonomist can initiate appropriate intervention strategies prior to the onset of chronic injuries.

Development of physical fitness standards for Canadian Armed Forces older personnel

The purpose of the study was to develop a minimum physical fitness standard for Canadian Forces personnel, 35 years and older, based on common criteria for physically demanding tasks. A random sample of 100 men and 76 women performed the Exercise Prescription (EXPRES) test and five physically demanding tasks that simulate common military tasks, while restricted, for safety reasons, to 90% maximal predicted heart rate. Results indicated poor predictive power, as variances ranged from 5 to 55% between EXPRES fitness scores and task performance. With approval from an expert panel, the 75th percentile score for each task was selected as the cutting criterion. The passing-group data were converted to Z-scores in order to determine the 5th percentile from each EXPRES item: these scores became the EXPRES fitness standard. The minimum fitness standard had a greater impact on women than on men but was representative of the passing groups for both sexes.

Methods for analysing county-level mortality rates

The identification of counties burdened by exceptionally high rates of mortality is a fundamental step in the development of state-based intervention and prevention strategies. However, the estimation of rates from small geographic areas presents special problems, especially for rare events. This paper compares the use of crude and age-standardized rates to the use of Poisson regression models and empirical Bayes models for analysing county-level mortality rates. The results demonstrate both practical and heuristic advantages of the empirical Bayes models. Age-standardized rates adjust for differences in age structure among countries but are vulnerable to extreme variability in county age-specific rates. In our example--an analysis of diabetes mortality rates--Poisson regression did not improve the variability of estimated county-level rates. Adjusted empirical Bayes estimates dramatically shrink the observed rates while preserving some separation of the counties with extreme rates. Also, empirical Bayes estimates of rates for countries with no observed deaths are shrunk close to the prior mean.

Risk factors for coronary heart disease mortality among persons with diabetes

Although coronary heart disease is a leading cause of morbidity and mortality among persons with diabetes, the risk factors for coronary heart disease have not been well established for this population. The authors performed a case-control analysis by using data from two large population-based surveys. Cases of persons who died of coronary heart disease were identified from the 1986 National Mortality Followback Survey, and controls were taken from behavioral risk factor surveys conducted in 35 states in 1988. Diabetic women younger than 55 years with no other risk factors for coronary heart disease had a 16-fold higher risk of dying from coronary heart disease than did women without diabetes. About one-third of younger women who died of coronary heart disease had diabetes. Diabetic men less than 45 years old with no other risk factors for coronary heart disease had an eightfold higher risk of coronary heart disease mortality. Among older white men and women, diabetes increased the risk of mortality from coronary heart disease about twofold. In younger diabetics, current cigarette smoking was associated with a 50% increase in risk, and high blood pressure increased the risk more than threefold. In the older age group, risk factors for coronary heart disease mortality were similar among those with and those without diabetes: Cigarette smoking and high blood pressure each were associated with about a twofold increase in risk. Diabetes is a particularly strong risk factor for mortality from coronary heart disease in young adults. Smoking and blood pressure control represent major opportunities to reduce the risk of coronary heart disease among persons with diabetes.

Development of physical fitness standards for Canadian Armed Forces younger personnel

The purpose of this study was to develop minimum physical fitness standards based on common task criteria for personnel younger than 35 years of age in the Canadian Armed Forces. A random sample of 66 men and 144 women performed the Exercise Prescription (EXPRES) test and five physically demanding tasks that simulated common military tasks. Common cutting scores were selected as the point at which 75% of the total weighted sample passed each task. Since there were significant differences between the sexes in task performance and technique execution, the groups were analyzed separately. Results indicated a range in variance of 14 to 48% between military task performance and physical fitness test score, thus suggesting that fitness measures are a poor predictor of task performance. Because of the low variance observed the passing group of each task was treated as a representative sample of subjects whose fitness profiles were indicative of those able to meet task criteria. The 5th percentile fitness scores of the passing group were proposed as the minimum fitness standard. These conditions resulted in fitness standards that were physically more demanding for women than for men.

Trends in diabetes and diabetic complications, 1980-1987

OBJECTIVE

Although diabetes is a major source of morbidity and mortality in the United States, only recently has a unified national surveillance system begun to monitor trends in diabetes and diabetic complications.

RESEARCH DESIGN AND METHODS

We established a diabetes surveillance system using data for 1980-1987 from vital records, the National Health Interview Survey, the National Hospital Discharge Survey, and the Health Care Financing Administration's records to examine trends in the prevalence and incidence of diabetes, diabetes mortality, hospitalizations, and diabetic complications.

RESULTS

From 1980 through 1987, the number of individuals known to have diabetes increased by 1 million--to 6.82 million. Age-standardized prevalence for diabetes increased 9% during this period, from 25.4 to 27.6/1000 U.S. residents (P = 0.03). The incidence of diabetes increased among women (P = 0.003), particularly among those greater than 65 yr old (P = 0.02). Age-standardized mortality rates (for diabetes as either an underlying or contributing cause) per 100,000 individuals with diabetes declined 12%, from 2350 to 2066. Annual mortality rates from stroke (as an underlying cause and diabetes as a contributing cause) and diabetic ketoacidosis declined 29% (P = 0.003) and 22% (P less than 0.001), respectively. During these 8 yr, hospitalization rates for major CVD and stroke (as the primary diagnoses and diabetes as a secondary diagnosis) increased 34% (P = 0.006) and 38% (P = 0.01), respectively. Also during this period, hospitalization rates increased 21% for diabetic ketoacidosis (P = 0.01) and 29% for lower-extremity amputations (P = 0.06). From 1982 through 1986, treatment for end-stage renal disease related to diabetes increased greater than 10% each year (P less than 0.001). The prevalence of diagnosed diabetes was nearly twice as high in blacks as in whites (P = 0.04). Blacks also had increased rates of lower-extremity amputation (P = 0.02), diabetic ketoacidosis (P less than 0.001), and end-stage renal disease (P = 0.01).

CONCLUSIONS

Diabetes surveillance data will be useful in planning, targeting, and evaluating public health efforts designed to prevent and control diabetes and its complications.

Seasonal variation in venison quality of mature, farmed red deer stags in New Zealand

Two studies involving 20 red deer (Cervus elaphus) stags were conducted to determine the effects of season on venison quality. In each study, five sexually mature red deer stags were slaughtered immediately preceding the rut (autumn) and five were slaughtered after the rut. Stags slaughtered postrut had lower carcass weights (25 to 30%) than those slaughtered prerut. Average bodywall thickness measurements above the 12th rib (an indicator of fat thickness) were approximately 31 mm prerut compared with 3 to 7 mm postrut. Individual muscles and retail cuts (which included subcutaneous and intermuscular fat) were heavier in prerut carcasses. There were significant decreases in intramuscular fat in both the longissimus muscle and the semimembranosus muscle. Postrut longissimus muscle steaks appeared brighter and(or) fresher than the other groups; color acceptability was negatively correlated (P less than .05) with fat content. Prerut streaks from both muscles were more tender than postrut steaks from those muscles. Overall desirability and tenderness were highly correlated (r = .94 and .82 for longissimus muscle and semimembranosus muscle, respectively).

Frequency of recording of diabetes on U.S. death certificates: analysis of the 1986 National Mortality Followback Survey

We used data from the 1986 National Mortality Followback Survey to estimate the frequency of recording of diabetes on death certificates and to determine factors associated with recording of diabetes among decedents aged 25 years and older who died in the U.S. in 1986. Among 2766 decedents for whom a history of diabetes was provided by a personal informant, diabetes was recorded on an estimated 38.2% of death certificates and was listed as the underlying cause of death on an estimated 9.6%. The frequency of recording of diabetes was strongly related to age and duration of diabetes--among those aged 25-44 years who had had diabetes for 15 or more years, the frequency of recording was 71.9%. When other listed causes of death included conditions that may have been related to diabetes, such as cardiovascular disease, diabetes was recorded between 45 and 70% of the time, depending on the other causes. Diabetes is usually not recorded on death certificates, and the likelihood of recording is related to decedent characteristics, particularly age, duration of diabetes, and co-morbidity.

Stages 1 and 2 epidermoid carcinoma of the glottic larynx: involvement of the anterior commissure

Data on 55 patients with stages 1 and 2 epidermoid carcinoma of the glottic larynx treated from 1978 to 1988 were retrospectively reviewed. Twenty-six patients had involvement of the anterior commissure (AC). Local and ultimate local control rates achieved, respectively, with mean follow-up of 41 months (range, 6-120 months), were as follows: 92% and 100% for patients without AC involvement and stage T1a lesions, 60% and 80% for patients without AC involvement and stage T2 lesions, 100% and 100% for patients with AC involvement and stage T1a lesions, 100% and 100% for patients with AC involvement and stage T1b lesions, and 75% and 100% for patients with AC involvement and stage T2 lesions. There was no correlation between the degree of response at completion of treatment and local control. There was no difference in the local control rate of patients with and without involvement of the AC. Factors associated with a decreased local control rate include extensive subglottic extension and use of a single lateral field technique. Surgical salvage after failure of radiation therapy is effective and can be performed with acceptable morbidity.

Stairclimbing kinematics on stairs of differing dimensions

The purpose of this study was to provide a kinematic description of the task of stair ascent and descent. Fifteen women were divided into short, medium, and tall subject groups. Three testing staircases of different riser and tread dimensions were used. Temporal and cinematographic data were collected simultaneously via switchmats and a high-speed camera, respectively. Measures of stairclimbing gait cycle duration, swing and stance phase durations, cadence, and velocity appeared to be systematically related to subject height. Stance (19% to 64%) and swing (36% to 81%) phase durations varied considerably depending on stair dimensions during stair descent. Less variation was observed in stance (50% to 60%) and swing (40% to 50%) values during tasks of stair ascent. Individuals appeared to adjust to stair dimensions by varying the flexion/extension patterns of the knee rather than those of the ankle or hip. Depending on the staircase climbed, knee flexion angles ranging from 83 degrees to 105 degrees were required. Stair dimensions, therefore, appeared to influence the temporal and angular kinematics of the lower limb during stairclimbing.

A family study of Gilles de la Tourette syndrome

Previous studies have demonstrated that Gilles de la Tourette syndrome (TS) is a familial disorder and that chronic tics (CT) and obsessive compulsive disorder (OCD) appear to be etiologically related to the syndrome. In the present study we report the results from a study of 338 biological relatives of 86 TS probands, 21 biologically unrelated relatives of adopted TS probands, and 22 relatives of normal subjects. The 43 first-degree relatives of the adopted TS and normal probands constituted a control sample. The rates of TS, CT, and OCD in the total sample of biological relatives of TS probands were significantly greater than in the relatives of controls. In addition, the morbid risks of TS, OCD, and CT were not significantly different in families of probands with OCD when compared to relatives of probands without OCD. These findings provide further evidence that OCD is etiologically related to TS.

Dynamic analysis of isoinertial lifting technique

The objectives of the study were threefold: (1) to quantify dynamic measures (displacement, velocity, force/acceleration, and power) of a 1·83 m isoinertial lift on an incremental lifting machine (ILM); (2)to identify any gender differences in ILM lifting technique; and (3) to assess the implications of these data for the use of the ILM as a screening device. One hundred and thirty-two military personnel (33 females and 99 males) completed a maximal isoinertial lifting test from a starting height of 0·34 m to a target height of 1·83 m on the ILM. A force transducer attached to the back of the armature provided continuous velocity and displacement data from which the displacement, velocity, acceleration/force, and power profiles were determined. These data were summarized into 37 lift parameters; 33 representing the dynamic components of the lift, and four representing averages taken across the entire lift. The results revealed that the 1·83 m isoinertial lift could be described in three phases: (1) a powerful pulling phase, which incorporated measures of maximal acceleration/force, velocity, and power; 2) a wrist changeover manoeuvre, wherein momentum was required to compensate for minimal force and acceleration values; and (3) a pushing phase, during which second maximal force and acceleration measures were attained. Statistically significant differences were found between genders on various parameters of the technique profiles, suggesting that the testing protocol may have placed different demands on males and females. Females spent a greater proportion of the total lift time in the pushing phase, and had less opportunity to generate power during the pulling phase. The resulting TLM scores may have underestimated the lifting capacity of females. It was recommended that females and males be given independent consideration in the design of ILM lifting protocols.

Four factor model to describe an isoinertial lift

The objectives of the study were threefold: (1) to develop an empirical description of dynamic factors involved in a test of lifting performance on an Incremental Lifting Machine (TLM) through application of principal components analysis; (2) to conduct gender analyses of the factor structures; and (3) to determine the stability of the structures with repeated sampling. An initial sample of 175 participants (79 females and 96 males) completed a maximal isoinertial lifting test from a starting height of 0·34 m to a target height of 1·83 m. A confirmatory sample of 132 participants (33 females and 99 males) completed the same 1LM test under identical conditions. A force transducer attached to the back of the armature provided continuous displacement data from which displacement, velocity, acceleration, force, and power profiles were determined. These data were summarized into 32 lift parameters, and then subjected to principal components analyses. For the dynamic parameters recorded for the initial sample, a four factor solution accounting for 78·9% of the variance was found to be optimal. Factor one (named Mid-Body Coordination and accounting for 24·7% of the variance) related to the timing and displacement of maximum velocity and power. Factor two (named Maximum Strength) contained maximum force and power measurements and accounted for 22·5% of the variance. Factor three (named Minimum Strength) related to minimum measures of force and power and accounted for 17·2% of the variance. Finally, factor four (named Lower Body Co-ordination and accounting for 14·4% of the variance) related to the timing and displacement of maximum force. Descriptions of the factors were developed in terms of their underlying biomechanical relationships. The four factor solution was found to be stable across genders, and it was replicated for the confirmatory sample. It was concluded that these dynamic factors possessed considerable scientific utility for future research.

Single camera photogrammetric technique for restricted 3D motion analysis

The purpose of this study was to use a single camera to determine the true elbow flexion angle with the arm plane oriented arbitrarily with respect to the camera. A mathematical theory was developed and a mechanical arm model was constructed to validate the theory. A static weightlifting skill was analysed to investigate the viability of the technique on the human subject. The validation of the theory showed the error associated with the elbow flexion angle was reduced from as high as 108 degrees when uncorrected to within 3 degrees when corrected by the technique. The elbow flexion angle of the human arm can be calculated to within 6 degrees of error for static weightlifting skill analysis.

The relationship between eggshell porosity and air space gas tensions measured before and during the parafoetal period and their effects on the hatching process in the domestic fowl

The partial pressure of gases in the air space were measured before and during the parafoetal period for domestic fowl eggs of the same initial weight but varying in eggshell conductance. Embryos developed and hatched normally from eggs with a wide range of shell conductance and resultant air space gas partial pressures. Air space PO2 levels measured just before pipping ranged from 55 to 65 mm Hg in low and high conductance eggs, respectively, whilst PCO2 levels ranged from 75 to 55 mm Hg. With increasing shell conductance embryos membrane-penetrated and pipped the shell later, but hatch time was unaffected. Membrane penetration and external pipping appeared to occur in response to the partial pressures of gas in the air space but not in response to one particular level of air space PO2 or PCO2. During the parafoetal stage air space PO2 decreased at about 3.8 mm Hg/h and air space PCO2 increased at about 1.8 mm Hg/h and these rates of change were unaffected by eggshell conductance.

Method for determining vertebral body positions in the sagittal plane using skin markers

A method by which the location of vertebral bodies can be estimated from the external profile of the spine in the sagittal plane is described. The technique involves a normalization of the curve from T1 to L5 and approximation using a cubic spline. Mapping functions are developed that enable the transformation of a skin profile to a vertebral centroid curve. Data were obtained for 13 subjects between the ages of 13 and 17 who had undergone lateral spinal radiographs with radiopaque skin markers over the vertebral spinal processes. Results suggested that vertebral body centroids could be estimated from the skin profile to a precision having a standard error of the estimate of 0.4 cm. This was improved to 0.2 cm if the lumbar curve were considered separately.