Routine sterile glove and instrument change at the time of abdominal wound closure to prevent surgical site infection (ChEETAh): a model-based cost-effectiveness analysis of a pragmatic, cluster-randomised trial in seven low-income and middle-income countries

BACKGROUND

Surgical site infection (SSI) is a major burden on patients and health systems. This study assessed the cost-effectiveness of routine change of sterile gloves and instruments before abdominal wall closure to prevent SSI.

METHODS

A decision-analytic model was built to estimate average costs and outcomes of changing gloves and instruments before abdominal wall closure compared with current practice. Clinical data were obtained from the ChEETAh trial, a multicentre, cluster-randomised trial in seven low-income and middle-income countries (LMICs), and costs were obtained from a study (KIWI) that assessed costs associated with SSIs in LMICs. Outcomes were measured as the percentage of surgeries resulting in SSIs. Costs were measured from a health-care provider perspective and were reported in 2021 US$. The economic analysis used a partially split single-country costing approach, with pooled outcomes data from all seven countries in the ChEETAh trial, and data for resource use and unit costs from India (KIWI); secondary analyses used resource use and costs from Mexico and Ghana (KIWI).

FINDINGS

In the base case, the average cost of the intervention was $259∙92 compared with $261∙10 for current practice (cost difference -$1∙18, 95% CI -4∙08 to 1∙33). In the intervention group, an estimated 17∙6% of patients had an SSI compared with 19∙7% of patients in the current practice group (absolute risk reduction 2∙10%, 95% CI 2∙07-2∙84). At all cost-effectiveness thresholds assumed ($0 to $14 000), the intervention had a higher likelihood of being cost-effective compared with current practice, indicating that the intervention was cost-effective. Similar results were obtained when the analysis using data from India was repeated using resource use and unit cost data from Mexico and Ghana.

INTERPRETATION

Routine sterile glove and instrument change before abdominal wall closure is effective and the costs are similar to those for current practice. Routine change of gloves and instruments before abdominal wall closure should be rolled out in LMICs.

FUNDING

National Institute for Health and Care Research (NIHR) Clinician Scientist Award, NIHR Global Health Research Unit Grant, and Mölnlycke Healthcare.

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

BACKGROUND

Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres.

METHODS

This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low-middle-income countries.

RESULTS

In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of 'single-use' consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low-middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia.

CONCLUSION

This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high- and low-middle-income countries.

Strategies to minimise and monitor biases and imbalances by arm in surgical cluster randomised trials: evidence from ChEETAh, a trial in seven low- and middle-income countries

BACKGROUND

Cluster randomised controlled trials (cRCT) present challenges regarding risks of bias and chance imbalances by arm. This paper reports strategies to minimise and monitor biases and imbalances in the ChEETAh cRCT.

METHODS

ChEETAh was an international cRCT (hospitals as clusters) evaluating whether changing sterile gloves and instruments prior to abdominal wound closure reduces surgical site infection at 30 days postoperative. ChEETAh planned to recruit 12,800 consecutive patients from 64 hospitals in seven low-middle income countries. Eight strategies to minimise and monitor bias were pre-specified: (1) minimum of 4 hospitals per country; (2) pre-randomisation identification of units of exposure (operating theatres, lists, teams or sessions) within clusters; (3) minimisation of randomisation by country and hospital type; (4) site training delivered after randomisation; (5) dedicated 'warm-up week' to train teams; (6) trial specific sticker and patient register to monitor consecutive patient identification; (7) monitoring characteristics of patients and units of exposure; and (8) low-burden outcome-assessment.

RESULTS

This analysis includes 10,686 patients from 70 clusters. The results aligned to the eight strategies were (1) 6 out of 7 countries included ≥ 4 hospitals; (2) 87.1% (61/70) of hospitals maintained their planned operating theatres (82% [27/33] and 92% [34/37] in the intervention and control arms); (3) minimisation maintained balance of key factors in both arms; (4) post-randomisation training was conducted for all hospitals; (5) the 'warm-up week' was conducted at all sites, and feedback used to refine processes; (6) the sticker and trial register were maintained, with an overall inclusion of 98.1% (10,686/10,894) of eligible patients; (7) monitoring allowed swift identification of problems in patient inclusion and key patient characteristics were reported: malignancy (20.3% intervention vs 12.6% control), midline incisions (68.4% vs 58.9%) and elective surgery (52.4% vs 42.6%); and (8) 0.4% (41/9187) of patients refused consent for outcome assessment.

CONCLUSION

cRCTs in surgery have several potential sources of bias that include varying units of exposure and the need for consecutive inclusion of all eligible patients across complex settings. We report a system that monitored and minimised the risks of bias and imbalances by arm, with important lessons for future cRCTs within hospitals.

Routine sterile glove and instrument change at the time of abdominal wound closure to prevent surgical site infection (ChEETAh): a pragmatic, cluster-randomised trial in seven low-income and middle-income countries

BACKGROUND

Surgical site infection (SSI) remains the most common complication of surgery around the world. WHO does not make recommendations for changing gloves and instruments before wound closure owing to a lack of evidence. This study aimed to test whether a routine change of gloves and instruments before wound closure reduced abdominal SSI.

METHODS

ChEETAh was a multicentre, cluster randomised trial in seven low-income and middle-income countries (Benin, Ghana, India, Mexico, Nigeria, Rwanda, South Africa). Any hospitals (clusters) doing abdominal surgery in participating countries were eligible. Clusters were randomly assigned to current practice (42) versus intervention (39; routine change of gloves and instruments before wound closure for the whole scrub team). Consecutive adults and children undergoing emergency or elective abdominal surgery (excluding caesarean section) for a clean-contaminated, contaminated, or dirty operation within each cluster were identified and included. It was not possible to mask the site investigators, nor the outcome assessors, but patients were masked to the treatment allocation. The primary outcome was SSI within 30 days after surgery (participant-level), assessed by US Centers for Disease Control and Prevention criteria and on the basis of the intention-to-treat principle. The trial has 90% power to detect a minimum reduction in the primary outcome from 16% to 12%, requiring 12 800 participants from at least 64 clusters. The trial was registered with ClinicalTrials.gov, NCT03700749.

FINDINGS

Between June 24, 2020 and March 31, 2022, 81 clusters were randomly assigned, which included a total of 13 301 consecutive patients (7157 to current practice and 6144 to intervention group). Overall, 11 825 (88·9%) of 13 301 patients were adults, 6125 (46·0%) of 13 301 underwent elective surgery, and 8086 (60·8%) of 13 301 underwent surgery that was clean-contaminated or 5215 (39·2%) of 13 301 underwent surgery that was contaminated-dirty. Glove and instrument change took place in 58 (0·8%) of 7157 patients in the current practice group and 6044 (98·3%) of 6144 patients in the intervention group. The SSI rate was 1280 (18·9%) of 6768 in the current practice group versus 931 (16·0%) of 5789 in the intervention group (adjusted risk ratio: 0·87, 95% CI 0·79-0·95; p=0·0032). There was no evidence to suggest heterogeneity of effect across any of the prespecified subgroup analyses. We did not anticipate or collect any specific data on serious adverse events.

INTERPRETATION

This trial showed a robust benefit to routinely changing gloves and instruments before abdominal wound closure. We suggest that it should be widely implemented into surgical practice around the world.

FUNDING

National Institute for Health Research (NIHR) Clinician Scientist Award, NIHR Global Health Research Unit Grant, Mölnlycke Healthcare.

Casemix, management, and mortality of patients rreseceiving emergency neurosurgery for traumatic brain injury in the Global Neurotrauma Outcomes Study: a prospective observational cohort study

BACKGROUND

Traumatic brain injury (TBI) is increasingly recognised as being responsible for a substantial proportion of the global burden of disease. Neurosurgical interventions are an important aspect of care for patients with TBI, but there is little epidemiological data available on this patient population. We aimed to characterise differences in casemix, management, and mortality of patients receiving emergency neurosurgery for TBI across different levels of human development.

METHODS

We did a prospective observational cohort study of consecutive patients with TBI undergoing emergency neurosurgery, in a convenience sample of hospitals identified by open invitation, through international and regional scientific societies and meetings, individual contacts, and social media. Patients receiving emergency neurosurgery for TBI in each hospital's 30-day study period were all eligible for inclusion, with the exception of patients undergoing insertion of an intracranial pressure monitor only, ventriculostomy placement only, or a procedure for drainage of a chronic subdural haematoma. The primary outcome was mortality at 14 days postoperatively (or last point of observation if the patient was discharged before this time point). Countries were stratified according to their Human Development Index (HDI)-a composite of life expectancy, education, and income measures-into very high HDI, high HDI, medium HDI, and low HDI tiers. Mixed effects logistic regression was used to examine the effect of HDI on mortality while accounting for and quantifying between-hospital and between-country variation.

FINDINGS

Our study included 1635 records from 159 hospitals in 57 countries, collected between Nov 1, 2018, and Jan 31, 2020. 328 (20%) records were from countries in the very high HDI tier, 539 (33%) from countries in the high HDI tier, 614 (38%) from countries in the medium HDI tier, and 154 (9%) from countries in the low HDI tier. The median age was 35 years (IQR 24-51), with the oldest patients in the very high HDI tier (median 54 years, IQR 34-69) and the youngest in the low HDI tier (median 28 years, IQR 20-38). The most common procedures were elevation of a depressed skull fracture in the low HDI tier (69 [45%]), evacuation of a supratentorial extradural haematoma in the medium HDI tier (189 [31%]) and high HDI tier (173 [32%]), and evacuation of a supratentorial acute subdural haematoma in the very high HDI tier (155 [47%]). Median time from injury to surgery was 13 h (IQR 6-32). Overall mortality was 18% (299 of 1635). After adjustment for casemix, the odds of mortality were greater in the medium HDI tier (odds ratio [OR] 2·84, 95% CI 1·55-5·2) and high HDI tier (2·26, 1·23-4·15), but not the low HDI tier (1·66, 0·61-4·46), relative to the very high HDI tier. There was significant between-hospital variation in mortality (median OR 2·04, 95% CI 1·17-2·49).

INTERPRETATION

Patients receiving emergency neurosurgery for TBI differed considerably in their admission characteristics and management across human development settings. Level of human development was associated with mortality. Substantial opportunities to improve care globally were identified, including reducing delays to surgery. Between-hospital variation in mortality suggests changes at an institutional level could influence outcome and comparative effectiveness research could identify best practices.

FUNDING

National Institute for Health Research Global Health Research Group.

Duodenal obstruction due to missed pre-duodenal portal vein in a patient with intestinal malrotation

Pre-duodenal portal vein (PDPV) is a rare anomaly and a rare cause of duodenal obstruction (DO), with only a few cases reported in the literature. We present an infant whose bilious vomiting persisted despite having Ladd's procedure for intestinal malrotation due to a missed diagnosis of DO from PDPV that was found at re-exploration. The patient was diagnosed with malrotation and had Ladd's procedure at 12 weeks of age, but bilious vomiting persisted post-operatively. The patient presented to us after 4 weeks, was clinically malnourished and dehydrated, resuscitation was done and re-exploratory laparotomy performed, where an obstructing PDPV was found and a duodeno-duodenostomy was performed anterior to PDPV. However, the patient died on post-operative day 7 probably from severe malnutrition due to delayed diagnosis and absence of parenteral nutrition. We conclude that PDPV may be a cause of DO in infants with malrotation and should be properly sought for during Ladd's procedure for possible bypass surgery if found.

Trapped fourth ventricle: A case report and review of literature

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In this patient the diagnosis was missed. Initially we thought it was shunt infection or malfunction. A shunt series and septic work up were both normal.

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CT scan of the brain was delayed for 10 days due to financial constraints.

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The only option available for treatment was a fourth ventriculoperitoneal shunt.

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However, the patient did well and was fine by 12 month of follow up.

Introduction and importance

Trapped fourth ventricle (TFV) also known as isolated fourth ventricle (IFV) is a rare clinico-radiologic entity with only a few cases reported in the literatures.

The aim of this article is to present the first case of this condition in our center and highlight the challenges of arriving at clinical diagnosis and treatment in a resource limited setting.

Case presentation

An 18 months old girl who had ventriculoperitoneal shunt insertion for post meningitic hydrocephalus 4 months earlier presented with restlessness, ataxia, fever and inability to control her neck of one-week duration. On examination she was restless and had retro-colis with a Glasgow Coma Scale (GCS) score of 11/15 (E4V2M5).

She had an associated facial and abducent nerve palsies with global hypertonia, hyper-reflexia and muscle power of 3/5.

She was initially treated for shunt infection and malfunction. However, shunt series and CSF analysis were within normal limits and CSF culture yielded no growth of microorganisms. A CT scan of the brain which was ordered earlier was delayed for 10 days due to financial constraints. The CT scan revealed a trapped fourth ventricle and slit lateral and third ventricle.

She had emergency fourth ventriculoperitoneal shunt inserted on the left because of the pre-existing supratentorial shunt on the right.

She did well after the surgery and was discharged on the 10th postoperative day. She was doing well 12 months after the surgery.

Relevance and impact

TFV may occur after insertion of VPS for post-meningitic hydrocephalus. This may present a diagnostic dilemma. Insertion of a second VPS may be an option in a resource limited setting.

Global variation in postoperative mortality and complications after cancer surgery: a multicentre, prospective cohort study in 82 countries

BACKGROUND

80% of individuals with cancer will require a surgical procedure, yet little comparative data exist on early outcomes in low-income and middle-income countries (LMICs). We compared postoperative outcomes in breast, colorectal, and gastric cancer surgery in hospitals worldwide, focusing on the effect of disease stage and complications on postoperative mortality.

METHODS

This was a multicentre, international prospective cohort study of consecutive adult patients undergoing surgery for primary breast, colorectal, or gastric cancer requiring a skin incision done under general or neuraxial anaesthesia. The primary outcome was death or major complication within 30 days of surgery. Multilevel logistic regression determined relationships within three-level nested models of patients within hospitals and countries. Hospital-level infrastructure effects were explored with three-way mediation analyses. This study was registered with ClinicalTrials.gov, NCT03471494.

FINDINGS

Between April 1, 2018, and Jan 31, 2019, we enrolled 15 958 patients from 428 hospitals in 82 countries (high income 9106 patients, 31 countries; upper-middle income 2721 patients, 23 countries; or lower-middle income 4131 patients, 28 countries). Patients in LMICs presented with more advanced disease compared with patients in high-income countries. 30-day mortality was higher for gastric cancer in low-income or lower-middle-income countries (adjusted odds ratio 3·72, 95% CI 1·70-8·16) and for colorectal cancer in low-income or lower-middle-income countries (4·59, 2·39-8·80) and upper-middle-income countries (2·06, 1·11-3·83). No difference in 30-day mortality was seen in breast cancer. The proportion of patients who died after a major complication was greatest in low-income or lower-middle-income countries (6·15, 3·26-11·59) and upper-middle-income countries (3·89, 2·08-7·29). Postoperative death after complications was partly explained by patient factors (60%) and partly by hospital or country (40%). The absence of consistently available postoperative care facilities was associated with seven to 10 more deaths per 100 major complications in LMICs. Cancer stage alone explained little of the early variation in mortality or postoperative complications.

INTERPRETATION

Higher levels of mortality after cancer surgery in LMICs was not fully explained by later presentation of disease. The capacity to rescue patients from surgical complications is a tangible opportunity for meaningful intervention. Early death after cancer surgery might be reduced by policies focusing on strengthening perioperative care systems to detect and intervene in common complications.

FUNDING

National Institute for Health Research Global Health Research Unit.

Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

BACKGROUND

Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world.

METHODS

This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231.

FINDINGS

Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p<0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05-2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p<0·001).

INTERPRETATION

Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication.

FUNDING

DFID-MRC-Wellcome Trust Joint Global Health Trial Development Grant, National Institute of Health Research Global Health Research Unit Grant.

Paediatric day-case surgery in a new paediatric surgical unit in Northwestern Nigeria

BACKGROUND

Day-case surgery is defined as when the surgical day-case patient is admitted for investigation or operation on a planned non-resident basis and who nonetheless requires facilities for recovery. A significant number of our patients were treated as day cases. This study was conducted to audit paediatric day-case surgery practice at our centre, to determine the indications as well as morbidity and mortality from day-case surgeries.

PATIENTS AND METHODS

This is a prospective study over a period of 14 months. The patients scheduled for surgeries were assessed in the paediatric surgical outpatient clinic and information obtained for each of the patients included age, sex, diagnosis, type of operation, type of anaesthesia and post-operative complications. The data were analysed using SPSS version 15.0 for windows.

RESULTS

A total of 182 patients were operated during the study period. The age range of patients was 0.5-156 months and the mean age was 46.6 months. There were 152 male patients (83.5%) and 30 female patients (16.5%). Most of the patients had intact prepuce for circumcision (34.1%). Two patients who had herniotomy developed superficial surgical site infections which were managed as outpatients. There were no readmissions or mortality.

CONCLUSION

Intact prepuce for circumcision as well as hernias and hydroceles is the most common day cases in our centre and is associated with low morbidity and no mortality.

Microsurgical Endoscope-Assisted Gravity-Aided Transfalcine Approach for Contralateral Metastatic Deep Medial Cortical Tumors

BACKGROUND

Traditional approaches to deep medial cortical tumors utilize transcortical or ipislateral interhemispheric approaches, which can result in cortical damage or retraction injury. To reduce these risks, the microscopic transfalcine approach has been previously described.

OBJECTIVE

To describe this approach performed with endoscopic assistance for metastatic tumor resection, demonstrating appropriate and safe tumor resection without injury to the contralateral hemisphere.

METHODS

Eleven consecutive patients harboring medial, deep metastatic tumors are reported. Tumor resection was performed with endoscopic assistance with 2 surgeons. Clinical outcomes are recorded.

RESULTS

All 11 patients underwent safe tumor resection. Gross total resection was achieved in 73% of patients. The application of the angled endoscope allowed for further tumor resection in 91% of patients. There were no complications in these patients. The contralateral brain did not demonstrate clinical or radiographic injury as well.

CONCLUSION

This series suggests that the endoscopic transfalcine approach in the lateral position can be a safe and effective approach for resecting medial interhemispheric metastatic tumors. It allows excellent tumor visualization, eliminates the need for brain retraction, minimizes parenchymal transgression, and improves surgical ergonomics. A familiarity of endoscopy and neuroanesthesia support is helpful when utilizing this approach.

Endoscopic and Gravity-Assisted Resection of Medial Temporo-occipital Lesions Through a Supracerebellar Transtentorial Approach: Technical Notes With Case Illustrations

BACKGROUND

Traditional approaches to medial temporo-occipital intra-axial brain tumors carry the risk of visual or language deficits related to brain retraction or transgression of deep fiber tracts. To reduce these risks, the microscopic supracerebellar transtentorial approach with the patient in the sitting position has been previously described for lesions in relative proximity to the tentorium.

OBJECTIVE

We describe this approach performed with endoscopic tumor resection to allow better visualization and a more ergonomic operating position.

METHODS

Four consecutive patients harboring a medial temporo-occipital lesion are reported. All were operated on while in the sitting position using frameless navigation and a supracerebellar transtentorial approach. Tumor resection was performed by 2 surgeons with endoscopic visualization.

RESULTS

Pathologies included intraparenchymal metastatic melanoma, cavernous hemangioma, and ganglioglioma, as well as an intraventricular metastatic tumor. The distance from the tentorium to the lesion ranged from 1 to 4 mm. Gross total resection was achieved in 3 of the 4 patients. The patient with a metastatic melanoma had an intentional near-total resection given the tumor encasing a branch of the posterior cerebral artery. The patient with the intraventricular tumor sustained a small but symptomatic infarct of the lateral geniculate region, resulting in a visual field deficit.

CONCLUSION

This small series suggests that the endoscopic supracerebellar transtentorial approach with the patient in the sitting position can be a safe and effective approach for removing medial temporo-occipital lesions. It allows excellent tumor visualization, eliminates the need for brain retraction, minimizes parenchymal transgression, and improves surgical ergonomics. Significant experience in endoscopy and excellent neuroanesthesia support are recommended before undertaking this approach.

Using the head as a mould for cranioplasty with methylmethacrylate

Methacrylate is a valuable tool to the neurosurgeon, even though it is currently being replaced by custom bone. During cranioplasty in the absence of custom bone, which is preformed based on the patients imaging, one has to make a cast to cover the cranial defect with or without the use of a mould. A good artificial skull outline is necessary for prevention of implant extrusion and acceptable cosmetic outcome. Using the patients head as a mould is a simple, cheap, and useful technique. An incision is made, and either a craniectomy or an attempt at skull elevation or separation of the scalp from dura is done based on the indication for the cranioplasty. The methacrylate monomer is mixed with its solvent. It is placed in between a sliced glove and then thinned out. Several layers of drapes are placed on the patients head, the acrylate which is in between the gloves is then placed on the drapes. As soon as it starts setting and the required shape obtained, it is removed and place on the sterile tray. It is then anchored and the wound closed. This technique produces good cosmetic outcome. However, the head must be properly protected from the risk of burns from the exothermic reaction. The technique is described in a 40-year-old driver who had a compound depressed skull fracture. He had a methylmethacrylate cranioplasty in the 9(th) week post trauma after allowing for wound healing. We recommend that this technique may be used in centers where custom bone is either too expensive or not available during cranioplasty in order to obtain a good outcome.

BHRF1 is highly conserved in primate virus analogues of Epstein-Barr virus

The Epstein-Barr virus (EBV) protein BHRF1 (BamHI rightward reading frame 1) was the first viral member of the Bcl-2 family of apoptosis-regulating proteins described. In vitro studies imply that BHRF1 is dispensable for virus-induced cellular transformation and virus replication. However, in contrast to several essential viral genes that show divergence outwith their functional domains, sequence data from a wide range of EBV isolates show there is striking conservation of the BHRF1 gene. Contrary to the in vitro studies, the high degree of conservation hints at a more important role for BHRF1. Analogous viruses are endemic in each of the higher primate species. Whilst their genome organisation is colinear, limited sequence analysis indicates that the viruses have diverged significantly and that only important functional domains of proteins are likely to be conserved. We have isolated the BHRF1 equivalents from the viruses which infect chimpanzees (Herpesvirus pan) and baboons (Herpesvirus papio) and find that they are highly homologous in both species, strengthening the hypothesis that BHRF1 plays a significant, evolutionarily conserved function in vivo and that changes to the protein are not well tolerated.

Voluntary and electrically evoked strength characteristics of obese and nonobese preadolescent boys

Overweight and obese children demonstrate inferior motor performance for strength- and power-related activities requiring support or lifting of body weight. Our purpose here was to determine whether the inferior performance could be attributed to a lower strength to muscle area ratio in the obese. Eleven nonobese (16.6% fat) and 13 obese (35.5% fat) boys (9-13 years old) volunteered for the study. Peak torque was measured during voluntary isometric and isokinetic elbow flexion and knee extension at four joint angles and four velocities, respectively. The contractile properties, twitch torque, time to peak torque, and half-relaxation time were evoked for the elbow flexors by percutaneous stimulation. Elbow flexor and knee extensor cross-sectional areas (CSA) were determined by computed axial tomography taken at the mid-upper arm and mid-thigh, respectively. Isometric and isokinetic elbow flexion and knee extension strength normalized for body weight were significantly (p less than 0.05) higher in the nonobese compared to the obese boys. There were no significant (p greater than 0.05) differences, however, between groups for elbow flexor and knee extensor CSA or for absolute and relative (normalized for muscle CSA or the product of muscle CSA and height, the latter accounting for differences in moment arm length) isometric, isokinetic, or evoked twitch torque for elbow flexion or knee extension. Likewise, there were no differences between groups for the time-related contractile properties, time to peak torque, or half-relaxation time. These findings suggest that there is no difference in the intrinsic strength or contractile properties of the elbow flexor and knee extensor muscles between obese and nonobese pre-adolescent boys and that other factors, such as the handicapping effect of excess fat mass, probably account for the reduced motor performance of the obese child.

Endurance capacity of untrained males and females in isometric and dynamic muscular contractions

The capacity to perform isometric and dynamic muscle contractions at different forces has been measured in two separate groups of subjects: 25 men and 25 women performed sustained isometric contractions of the knee-extensor muscles of their stronger leg to fatigue, at forces corresponding to 80%, 50% and 20% of the maximum voluntary force of contraction (MVC). The second experimental model involved a bilateral elbow-flexion weight lifting exercise. Eleven women and 12 men performed repetitions at loads corresponding to 90%, 80%, 70%, 60% and 50% of maximum load (1RM), at a rate of 10 X min-1 to the point of fatigue. Males were stronger (p less than 0.001) than females in both the static (675 +/- 120 N vs 458 +/- 80 N; mean +/- SD) and dynamic (409 +/- 90 N vs 190 +/- 33 N) contractions. Isometric endurance time of the males at a force corresponding to 20% of MVC was less than that of the females (180 +/- 51 s vs 252 +/- 56 s; p less than 0.001) but there was no difference between the sexes at 50% or 80% of MVC. Similarly, when the sexes were compared using dynamic elbow-flexion exercise, the female subjects were able to perform a greater number of repetitions than males at loads of 50% (p less than 0.005), 60% (p less than 0.001) and 70% (p less than 0.025) of 1RM, but there was no difference between the sexes at loads of 80% or 90% of 1RM.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of joint position on ankle plantarflexion in humans

The contractile properties of the triceps surae (medial and lateral gastrocnemii and soleus) have been studied in humans. In comparison with most other human muscles, the triceps complex had a slow twitch (mean contraction and half-relaxation times 112.4 +/- 11.1 and 99.6 +/- 14.4 ms, respectively) and a low tetanus fusion frequency (60 Hz). Stretching the muscle caused both the contraction and half-relaxation times to become longer. With the knee bent, the optimum length for torque development corresponded to almost full dorsiflexion of the ankle. Similar results were obtained with the knee extended. The optimum position of the ankle differed considerably from the position of the joint when the leg was at rest. Although the position of the ankle joint affected electromyographic (EMG) activity recorded during maximal voluntary contraction, there was little change in the EMG-to-M wave ratio.

Physiology of weight-lifting exercise

This review describes the major features of skeletal muscle adaptation to weight-lifting exercise. Changes in contraction time, fiber size, and possibly fiber number may result in response to prolonged weight-training. Effective strength-training programs, both for athletics and rehabilitation, require recognition of the concept of "specificity of training," realization of the tendency of human skeletal muscle to adapt differently to different forms of physiologic stress.

Influence of joint position on ankle dorsiflexion in humans

A method is described for investigating the contractile properties of the dorsiflexor muscles of the ankle. With the joint in the midposition the tibialis anterior was found to contribute less than half of the maximum voluntary torque, the remainder presumably being provided by the long extensors of the toes. The mean contraction and half-relaxation times of tibialis anterior muscles in healthy young men were 81.2 +/- 7.4 (SD) ms and 83.6 +/- 17.2 ms, respectively. When the tibialis anterior was stretched, the twitch became slower and more complete fusion of the contractions occurred during tetanic stimulation at low frequencies. Stimulation of tibialis anterior at 30 and 40 Hz disclosed that the optimum length of the muscle corresponded to about 10 degrees of plantarflexion. Maximum voluntary torque was also developed at 10 degrees of plantarflexion and decreased sharply as the ankle was dorsiflex beyond 5 degrees. The position assumed by the ankle joint at rest depended on whether the subject was sitting, standing, or lying, but was always greater, in the plantarflexed direction, than the "optimum" position for torque development. At low rates of stimulation the torque continued to increase throughout the full range of plantarflexion, probably because of the elasticity of the tendon. During maximum effort motoneuronal excitability did not appear to be influenced significantly by changes in joint angle.

Continuous vs. interval training: a review for the athlete and the coach

Both interval and continuous training are necessary in order to maximize the endurance athlete's potential for competition. Continuous submaximal training exerts its greatest effect upon the oxygen transport system of the body, while high intensity endurance-interval training exerts its greatest effect on the structural and biochemical properties of the muscle. The physiological basis for both forms of training is discussed and recommendations are made for year-round training and training to elevate the anaerobic threshold.

The glycerylphosphorylcholine content of the rat epididymis after injecting alpha-chlorohydrin and ligating the vasa efferentia

The concentration of GPC in the 4 segments (initial segment, caput, corpus and cauda) of the rat epididymis was examined at various times (4 hours. 2, 5, 10 and 20 days) following injection of a lesion-forming dose (90 mg/kg body weight) of alpha-chlorohydrin and bilateral ligation of the vasa efferentia. There was a reduction in the overall GPC concentration of the epididymis 2 days after both treatments and a further decrease until 20 days when a slight increase occurred. It is suggested that a lesion-forming dose of alpha-chlorohydrin, like ligation of the vasa efferentia, could inhibit the synthesis and/or release of GPC within the epididymis by blocking off androgen supply in the testicular fluid.