A prospective cohort study of hamstring injuries in competitive sprinters: preseason muscle imbalance as a possible risk factor

BACKGROUND

Hamstring injuries are common in sprinters. Identifying preseason risk factors is essential to target injury-prone athletes and develop injury preventive measures.

OBJECTIVE

To investigate the incidence of hamstring muscle injury in sprinters over an athletic season and to explore the preseason predictor of this injury.

DESIGN

Prospective cohort study.

PARTICIPANTS

44 sprinters from the Hong Kong Sports Institute, the Hong Kong Amateur Athletic Association and intercollegiate athletic teams were recruited.

METHODS

Preseason assessment of hamstring flexibility, concentric and eccentric isokinetic peak torque and peak torque angle were obtained at the beginning of an athletic season. The athletes were followed over 12 months and were asked to report all injuries resulting from training and competition.

RESULTS

Eight athletes sustained hamstring injuries over the season. The injury rate was 0.87 per 1000 h of exposure. The incidence of injuries was higher at the beginning of the season, with 58.3% injuries occurring in the first 100 h of exposure. Cox regression analysis revealed that athletes with a decrease in the hamstring : quadriceps peak torque ratio of less than 0.60 at an angular velocity of 180 degrees/s have a 17-fold increased risk of hamstring injury.

CONCLUSION

Performing preseason hamstring : quadriceps peak torque ratio assessments may be useful to identify sprinters susceptible to hamstring injury.

Mechanisms of stretch-induced muscle damage in normal and dystrophic muscle: role of ionic changes

Muscle damage, characterized by prolonged weakness and delayed onset of stiffness and soreness, is common following contractions in which the muscles are stretched. Stretch-induced damage of this sort is more pronounced in the muscular dystrophies and the profound muscle damage observed in these conditions may involve similar pathways. It has been known for many years that damaged muscles accumulate calcium and that elevating calcium in normal muscles simulates many aspects of muscle damage. The changes in intracellular calcium, sodium and pH following stretched contractions are reviewed and the various pathways which have been proposed to allow ion entry are discussed. One possibility is that TRPC1 (transient receptor potential, canonical), a protein which seems to form both a stretch-activated channel and a store-operated channel, is the main source of Ca(2+) entry. The mechanisms by which the changes in intracellular ions contribute to reduced force production, to increased protein breakdown and to increased membrane permeability are considered. A hypothetical scheme for muscle damage which incorporates these ideas is presented.

Ten year survival and outcomes in a prospective cohort of new onset Chinese Parkinson's disease patients

OBJECTIVE

The 10 year outcomes and impact of motor and non-motor features on survival of a cohort of new onset Chinese Parkinson's disease (PD) patients were prospectively studied.

METHOD

A cohort of new onset PD patients from 1995 to 2002 was recruited from a regional hospital based movement disorder clinic. Subjects were classified into postural instability gait disorder (PIGD), tremor predominant type or mixed subtypes at presentation. All were evaluated yearly for development of sensory complaints, first significant fall, hallucinations, dementia, postural hypotension, speech disturbances, dysphagia and postural instability persisted during 'on' medication state (PIPon). Mortality and predictors of death were determined.

RESULTS

171 new onset PD patients were recruited. After a mean follow-up of 11.3±2.6 years, 50 (29%) patients died. The standardised mortality ratio was 1.1 (CI 0.8 to 1.5, p=0.34). 83 (49%) developed dementia, 81 (47%) had psychosis and 103 (60%) had sensory complaints. Postural hypotension was found in 58 (34%) patients, 108 (63%) had PIPon, 101 (59%) had falls, 102 (60%) had dysphagia, 148 (87%) had freezing of gait and 117 (68%) had speech disturbances. 46 (27%) were institutionalised whereas 54 (32%) lived independently. Dementia (HR 5.0, 95% CI 2.1 to 13.0), PIPon (HR 2.8, 95% CI 1.2 to 6.8), older onset (HR 1.05, 1 year increase in age, 95% CI 1.0 to 1.1) and PIGD type (HR 2.1, 95% CI 1.2 to 3.7) were independent predictors of death.

CONCLUSIONS

10 years into PD, a significant proportion of patients developed dopa resistant motor and non-motor features. Older onset, PIGD type, PIPon and dementia had a negative impact on survival. Standardised mortality ratio was 1.1.

Self-expandable stainless steel endoprostheses for treatment of malignant bile duct obstruction

The Wallstent biliary endoprosthesis is a mesh of stainless steel that is delivered percutaneously over a 7-French catheter but expands to achieve a 1-cm lumen when released across a bile-duct stricture. The small transhepatic track required makes insertion easier, less painful, and probably safer when compared with plastic stents, and the large internal lumen reduces the rate of occlusion by encrusted bile. Wallstent endoprostheses were inserted under local anesthesia in 41 consecutive patients with malignant obstructive jaundice. Biliary drainage was considered the treatment of choice in all of these patients. The diagnosis was based on biopsy results in 32 patients and on radiologic appearances in nine. The patients were followed up in outpatient clinics for 16 months and had repeated radiologic examinations only if they had symptoms suggesting stent occlusion. No cases of hemobilia due to damaged hepatic vessels occurred. Two patients had septicemia treated with antibiotics. Three patients had recurrent jaundice due to growth of tumor below or above the stents. Endoprosthesis migration was not seen. No cases of stent occlusion due to encrustation of bile occurred. The median survival of patients was 105 days (range, 10-545 days). Our experience shows that Wallstent endoprostheses can be inserted with little discomfort for the patient and with relatively few complications. They provide good palliation in patients with malignant obstructive jaundice.

The role of patient factors and implant position in squeaking of ceramic-on-ceramic total hip replacements

We investigated factors that were thought to be associated with an increased incidence of squeaking of ceramic-on-ceramic total hip replacements. Between June 1997 and December 2008 the three senior authors implanted 2406 primary total hip replacements with a ceramic-on-ceramic bearing surface. The mean follow-up was 10.6 years. The diagnosis was primary osteoarthritis in each case, and no patient had undergone previous surgery to the hip. We identified 74 squeaking hips (73 patients) giving an incidence of 3.1% at a mean follow-up of 9.5 years (4.1 to 13.3). Taller, heavier and younger patients were significantly more likely to have hips that squeaked. Squeaking hips had a significantly higher range of post-operative internal (p = 0.001) and external rotation (p = 0.003) compared with silent hips. Patients with squeaking hips had significantly higher activity levels (p = 0.009). A squeaking hip was not associated with a significant difference in patient satisfaction (p = 0.24) or Harris hip score (p = 0.34). Four implant position factors enabled good prediction of squeaking. These were high acetabular component inclination, high femoral offset, lateralisation of the hip centre and either high or low acetabular component anteversion. This is the largest study to date to examine patient factors and implant position factors that predispose to squeaking of a ceramic-on-ceramic hip. The results suggest that factors which increase the mechanical forces across the hip joint and factors which increase the risk of neck-to-rim impingement, and therefore edge-loading, are those that predispose to squeaking.

Bile duct obstruction: radiologic evaluation of level, cause, and tumor resectability

In a prospective study of 65 patients with bile duct obstruction, various radiologic modalities were compared for their capability to demonstrate the level and cause of obstruction and to indicate accurately tumor resectability. Ultrasound (US) was performed in 65 patients, computed tomography (CT) in 51, direct cholangiography (DC) in 57, and angiography in 35. The level of obstruction was correctly indicated by US in 95% of patients and by CT in 90%, and the cause was correctly indicated by US in 88%, by CT in 63%, and by DC in 89%. In predicting tumor resectability, US was correct in 71% of patients, compared with 42% for CT, 58% for DC, and 25% for angiography. US therefore appears to be the single most useful modality in the evaluation bile duct obstruction.

Influence of eicosapentaenoic acid supplementation on lean body mass in cancer cachexia

Cancer cachexia is characterised by a progressive loss of muscle, resulting in functional impairment and shorter survival. Eicosapentaenoic acid, an n-3 polyunsaturated fatty acid found in fish, has been studied for its role as an anti-cachexia therapy. Initial results of eicosapentaenoic supplementation in advanced cancer were promising with improvements in lean body mass (LBM), appetite and quality of life. However, subsequent larger phase III clinical trials reported minimal benefits of supplementation. Recently, several studies have used different study designs, which may provide insight on the effectiveness of eicosapentaenoic in cancer cachexia and also on potential sources of divergent results in previous trials. This review examines the potential benefit of eicosapentaenoic supplementation on LBM and discusses limitations with current studies to identify methods which may aid in progressing the research of future clinical trials.

A systematic review of interventions to prevent lower limb soft tissue running injuries

OBJECTIVES

To assess the available evidence for preventive strategies for lower limb soft tissue injuries caused by running.

METHODS

An electronic database search was conducted using The Cochrane Musculoskeletal Injuries Group Specialised Register, The Cochrane Controlled Trials Register, Medline, Embase, Sport Discus, Heracles, Atlantes, Biosis, Cinahl, Scisearch, Current Contents, Index To Theses and Dissertation Abstracts. Any randomised or quasi-randomised trials evaluating interventions to prevent running injuries to lower limb soft tissue were included. The eligibility of trials for inclusion and the quality of the trials were independently assessed by two reviewers.

RESULTS

Exposure to a high training load (duration, frequency, or running distance) increases the risk of injury, and thus modification of the training schedule can reduce the incidence of injury. The effectiveness of stretching exercises and of insoles in the prevention of lower extremity soft tissue injuries caused by running is not known. Wearing a knee brace with a patellar support ring may be effective in the prevention of anterior knee pain caused by running.

CONCLUSIONS

This review provides evidence for the effectiveness of the modification of training schedules in reducing lower limb soft tissue running injuries. More studies are required to quantify the optimal training loads and to confirm that knee braces can prevent knee pain. It is important to note that the studies included in this review had few female participants therefore the results may not be generalisable.

The effect of obesity on the mid-term survival and clinical outcome of cementless total hip replacement

The outcome of total hip replacement (THR) is potentially affected by the body mass index (BMI) of the patient. We studied the outcome of 2026 consecutive primary cementless THRs performed for osteoarthritis. The mean follow-up was 6.3 years (0 to 11.71) and no patient was lost to follow-up for survival analysis. The patients were divided into two groups according to their BMI as follows: non-obese (BMI < 30 kg/m(2)) and obese (BMI > or = 30 kg/m(2)). The obese patient undergoing surgery was found to be significantly younger (p < 0.001). The log-rank test for equality of survival showed no difference in the mid-term survival (p = 0.552) with an estimated survival at 11 years of 95.2% (95% CI 92.5 to 98.0) in the non-obese and 96.7% (95% CI 94.9 to 98.5) in the obese groups. The clinical and radiological outcome was determined in a case-matched study performed on 134 obese individuals closely matched with 134 non-obese controls. The non-obese group was found to have a significantly higher post-operative Harris hip score (p < 0.001) and an increased range of movement, but overall satisfaction with surgery was comparable with that of the obese patients. Radiological analysis of the acetabular and femoral components showed no significant differences with regard to radiolucent lines, osteolysis, ingrowth of the femoral component, the acetabular inclination angle or alignment of the femoral component. Our results suggest that the survival of cementless THR is not adversely affected by obesity. Obese patients can therefore be counselled that despite a lower clinical score, they should expect to be satisfied with the result of their THR with a mid-term survival rate equivalent to that of non-obese patients.

Outcome analysis of Zenker's diverticulectomy and cricopharyngeal myotomy

BACKGROUND

The optimal management of Zenker's diverticula is controversial in part because of the method of categorizing treatment success or failure. Subjective and objective radiologic tests have been used to evaluate the various treatment modalities. There seems to be poor correlation between subjective and objective findings, and we tested this hypothesis in a group of patients undergoing one form of therapy (diverticulectomy and cricopharyngeal myotomy [CPM]).

METHODS

Eighteen consecutive patients underwent Zenker's diverticulectomy and CPM. Postoperative symptoms and abnormalities detected by barium esophagrams were evaluated after a mean follow-up of 30.3 months (range, 7-74 months).

RESULTS

Three of 18 patients (17%) complained of dysphagia (2 occasional and not bothersome; 1 bothersome and affecting dietary intake). Postoperative static contrast esophagrams were interpreted without knowledge of the subjective symptoms. Small diverticula were identified in 8 patients (44%). There was poor correlation between symptoms and objective radiographic abnormalities with agreement of 56% and a kappa statistic of 0.23.

CONCLUSIONS

Objective radiographic abnormalities are far more common than subjective complaints following diverticulectomy and CPM. Postoperative static contrast radiography is not routinely required and may be misleading because of the poor correlation between symptoms and radiographic findings. The value of dynamic videofluoroscopy needs to be evaluated.

Differences in risk factors for incident and recurrent small-for-gestational-age birthweight: a hospital-based cohort study

OBJECTIVE

Examine whether small-for-gestational-age (SGA) risk factors differed by prior SGA birth.

DESIGN

Hospital-based cohort study.

SETTING

Utah, USA.

POPULATION

Electronic medical record data from 25,241 women who were nulliparous at study entry with ≥2 subsequent consecutive singleton deliveries (2002-2010).

METHODS

Estimated adjusted relative risks (RR) and 95% confidence intervals (95% CI) for the association between second pregnancy characteristics and SGA risk. Tested for risk factor differences between recurrence and incidence (Pdifference).

MAIN OUTCOME MEASURES

Second pregnancy incident (n = 1067) and recurrent SGA (n = 484) determined using a population-based reference.

RESULTS

SGA complicated 20.3 and 4.5% of deliveries to women with and without a prior SGA birth, respectively. Young maternal age (Pdifference = 0.01) and pregnancy hypertensive diseases (Pdifference = 0.03) were associated with incident but not recurrent SGA. Significant risk factors for incidence and recurrence were smoking (incident RR = 1.64 [95% CI 1.22-2.19]; recurrent RR = 1.59 [95% CI 1.17-2.17]), short stature (incident RR = 1.34 [95% CI 1.16-1.54]; recurrent RR = 1.54 [95% CI 1.31-1.82]), prepregnancy underweight (incident RR = 1.32 [95% CI 1.07-1.64]; recurrent RR = 1.30 [95% CI 1.03-1.64]), and inadequate weight gain (incident RR = 1.41 [95% CI 1.22-1.64]; recurrent RR = 1.33 [95% CI 1.10-1.60]). Race-ethnicity, marital or insurance status, alcohol, diabetes, asthma, thyroid disease, depression, or interpregnancy interval were not associated with incidence or recurrence.

CONCLUSION

There was considerable overlap in the risk factors for SGA recurrence and incidence. Recurrence and incidence risk factors included smoking, short stature, underweight, and inadequate weight gain. Maternal age and hypertensive diseases increased the risk for incidence only. Regardless of the SGA definition, some potentially modifiable risk factors for recurrence were identified.

Impact of socioeconomic status on the prevalence of dementia in an inner city memory disorders clinic

BACKGROUND

Socioeconomic status (SES) has been identified as a possible risk factor for the development of dementia, with low SES shown to be associated with a higher prevalence of dementia, increased psychiatric comorbidity and worse baseline cognitive functioning. Few studies have actually looked at the impact of SES within a clinical population using multiple measures of SES and cognition.

METHODS

Data on 217 patients seen in an Inner City Memory Disorders Clinic were analyzed with respect to demographic status, clinical status and SES. Correlations were then examined looking at the relationship of SES to clinical variables and neurocognitive status. Regression analysis was undertaken to examine the relative contribution of individual sociodemographic factors to a diagnosis of dementia.

RESULTS

In general, there was wide variation in the sample examined with respect to most measures of SES. Approximately one third (36%) of the sample had a diagnosis of dementia, the mean age was 66.1 years and the mean Mini-mental State Examination score was relatively high (25.4). There was a strong association between age, individual annual income range, education, medical comorbidity and a diagnosis of dementia, with increased age and medical comorbidity being the strongest predictors.

CONCLUSION

Increased age, low education, high medical comorbidity and low annual income are all associated with a diagnosis of dementia in an inner city setting. Age and medical comorbidity appear to be more strongly associated with a diagnosis of dementia than SES in an inner city setting.

Agalactosyl IgG and antibody specificity in rheumatoid arthritis, tuberculosis, systemic lupus erythematosus and myasthenia gravis

Agalactosyl IgG (Gal(0) is a glycoform lacking terminal galactose from the oligosaccharides situated on the Fc. The percentage of circulating IgG that is Gal(0) is increased in a a number of autoimmune diseases, and in certain chronic infections associated with autoantibody production. However it is not known whether this represents decreased galactosylation of all IgG, or an increase in the relative concentration of a subset of agalactosyl antibodies of specificity relevant to the disease process. Since there is currently no way to separate agalactosyl from galactosylated IgG, we devised an assay for the relative degree of galactosylation of antibody to tetanus toxoid (TT), an antigen irrelevant to the diseases studied, and compared this value with the %Gal(0) of the whole circulating IgG. In rheumatoid arthritis (RA) and tuberculosis (TB), a raised %Gal(0) in serum IgG was reflected in a parallel rise in the extent to which antibody to TT was agalactosyl. In SLE a rise in %Gal(0) was seen in the presence of very little rise in agalactosyl anti-TT, and in myasthenia gravis (MG), where serum %Gal(0) is normal, an abnormally low percentage of the anti-TT was agalactosyl. These results imply that in RA and TB a systemic influence is downregulating the galactosylation even of irrelevant IgG. However in SLE and MG antibodies of specificities not studied here must be responsible for the %Gal(0) found in serum. It remains to be seen whether these are the autoantibodies involved in the disease process.

Interventions for preventing lower limb soft-tissue injuries in runners

BACKGROUND

Overuse musculoskeletal injuries occur frequently in runners. Suggestions for prevention have focused on stretching exercises, modifying training schedules and the use of protective devices such as braces and insoles. To date, no systematic analysis of the literature on the effectiveness of these strategies in the prevention of overuse injuries has been published.

OBJECTIVES

The objective of the review was to evaluate the evidence from randomised controlled trials on the prevention of lower limb soft-tissue running injuries.

SEARCH STRATEGY

An electronic database search included The Cochrane Musculoskeletal Injuries Group specialised register (date of last search October 2000), The Cochrane Controlled Trials Register (The Cochrane Library, Issue 3, 1999), MEDLINE (from 1966), EMBASE (from 1980), SPORT Discus (1975-2000), HERACLES (1975-2000), ATLANTES (1980-1996), BIOSIS, CINAHL, SCISEARCH, Current Contents, Index To Theses and Dissertation Abstracts. Date of last search for these databses: May 2000.

SELECTION CRITERIA

Any randomised or quasi-randomised trials evaluating interventions to prevent lower limb soft-tissue running injuries.

DATA COLLECTION AND ANALYSIS

All trials fulfilling the selection criteria were assessed by two reviewers independently. Data were also extracted independently by the two reviewers using a pre-derived data extraction form. Exploratory analyses, including pooling of results from groups of trials of similar designs were undertaken, using a fixed effects model. Results were reported as relative risks (RR) with 95 per cent confidence intervals (95% CI).

MAIN RESULTS

Twelve trials with 8,806 participants were included. In one trial, a single control group was matched to three different included intervention groups. The effectiveness of stretching exercises (5 trials, 1944 participants in the intervention groups, 3159 controls), and of insoles and footwear modification (5 trials, 903 participants in the intervention groups, 3006 controls) in the prevention of lower extremity soft tissue injuries associated with running is unknown. Reducing the distance, frequency and duration of running may be effective in the prevention of lower extremity soft tissue injuries associated with running (3 trials, 514 participants in intervention groups, 1663 controls). Wearing a knee brace with a patellar support ring may be effective in the prevention of running-associated anterior knee pain (1 trial, 27 participants in the intervention group, 33 controls).

REVIEWER'S CONCLUSIONS

This review provides some evidence for the effectiveness of the modification of training schedules, but there is insufficient evidence to determine the effectiveness of stretching exercises for major lower limb muscle groups in reducing lower limb soft-tissue running injuries. More studies are required to confirm that knee braces may prevent knee pain, to clarify the role of stretching, and to quantify optimal training loads. Generalisability of the results may be limited by the intensive nature of military training (the context for most of the studies) and the inclusion of only small numbers of women.

Characteristics of psychiatrists who perform ECT

OBJECTIVE

Use of ECT is highly variable, and previous study has linked its availability to the geographic concentration of psychiatrists. However, less than 8% of all U.S. psychiatrists provide ECT. The authors analyzed the characteristics of psychiatrists who use ECT to understand more fully the variation in its use and how changes in the psychiatric workforce may affect its availability.

METHOD

Data from the 1988-1989 Professional Activities Survey were examined to investigate the influence of demographic, training, clinical practice, and geographic characteristics on whether psychiatrists use ECT.

RESULTS

Psychiatrists who provided ECT were more likely to be male, to have graduated from a medical school outside the United States, and to have been trained in the 1960s or 1980s rather than the 1970s. They were more likely to provide medications than psychotherapy, to practice at private rather than state and county public hospitals, to treat patients with affective and organic disorders, and to practice in a county containing an academic medical center.

CONCLUSIONS

Demographic and training characteristics significantly influence whether a psychiatrist uses ECT. Opposing trends in the U.S. psychiatric workforce could affect the availability of the procedure. Expanding training opportunities for ECT and making education, training, and testing more consistent nationwide could improve clinicians' consensus about ECT and narrow variation in its use.

A proteinase inhibitor II of Solanum americanum is expressed in phloem

Although proteinase inhibitor proteins are known to confer insect resistance in transgenic plants, their endogenous roles remain undefined. Here, we describe the expression of a proteinase inhibitor II (PIN2) protein from Solanum americanum in phloem of stems, roots and leaves suggesting a novel endogenous role for PIN2 in phloem. The phloem consists of parenchyma cells, sieve elements (SE), and companion cells (CC) which are in close association with SE. We isolated two cDNAs encoding PIN2, SaPIN2a and SaPIN2b, from a S. americanum cDNA library using a tomato PIN2 cDNA as hybridization probe. SaPIN2a shows 73.6% identity to SaPIN2b. Southern blot analysis confirmed that two genes occur in S. americanum. Northern blot analysis showed that both are wound-inducible and are expressed in flowers. Unlike SaPIN2b and other previously characterized plant PIN2 proteins, SaPlN2a is abundantly expressed in stems. In situ hybridization studies on stem sections showed that SaPIN2a mRNA is expressed in CC and some SE, likely the immature developing SE. of external and internal phloem. Western blot analysis using SaPIN2a-specific antibodies showed SaPIN2a accumulation in stems, leaf midribs and fruits. Immunohistochemical localization, using these antibodies, revealed SaPIN2a expression in external and internal phloem of stem. Immunoelectron microscopy of stem, root and leaf sections further localized SaPIN2a to the CC and predominantly to the SE, particularly the parietal cytoplasm adjacent to the cell wall, the lumen and the sieve-area pores. These results suggest that, other than a possible role in plant defense, SaPIN2a could be involved in regulating proteolysis in the SE.

Angiomyolipomas of the liver in tuberous sclerosis

Although the association of tuberous sclerosis and renal angiomyolipomas is well established, the occurrence of hepatic hamartomatous lesions in this disease is less well documented. We describe two cases of tuberous sclerosis with associated multiple intrahepatic angiomyolipomas, and we review the literature on this subject. Radiologically, angiomyolipomas can range from entirely lipomatous to completely solid, features which are present in our cases. A characteristic finding of the hepatic involvement in this disease appears to be the multiplicity of the lesions. We suggest that in the setting of tuberous sclerosis it is reasonable to assume that intrahepatic lesions represent angiomyolipomas. However, in nontuberous sclerosis patients with similar findings malignancy cannot be excluded.

Effect of eccentric contraction-induced injury on force and intracellular pH in rat skeletal muscles

The effect of eccentric contraction on force generation and intracellular pH (pH(i)) regulation was investigated in rat soleus muscle. Eccentric muscle damage was induced by stretching muscle bundles by 30% of the optimal length for a series of 10 tetani. After eccentric contractions, there was reduction in force at all stimulation frequencies and a greater reduction in relative force at low-stimulus frequencies. There was also a shift of optimal length to longer lengths. pH(i) was measured with a pH-sensitive probe, 2',7'-bis-(2-carboxyethyl)-5(6)-carboxyfluorescein AM. pH(i) regulation was studied by inducing an acute acid load with the removal of 20-40 mM ammonium chloride, and the rate of pH(i) recovery was monitored. The acid extrusion rate was obtained by multiplying the rate of pH(i) recovery by the buffering power. The resting pH(i) after eccentric contractions was more acidic, and the rate of recovery from acid load post-eccentric contractions was slower than that from postisometric controls. This is further supported by the slower acid extrusion rate. Amiloride slowed the recovery from an acid load in control experiments. Because the Na(+)/H(+) exchanger is the dominant mechanism for the recovery of pH(i), this suggests that the impairment in the ability of the muscle to regulate pH(i) after eccentric contractions is caused by decreased activity of the Na(+)/H(+) exchanger.

Shift of Peak Torque Angle After Eccentric Exercise

This study aims to investigate the changes in the mechanical properties of quadriceps muscle following a sub-maximal concentric-eccentric stepping exercise protocol. Twenty-four untrained healthy subjects aged 21.9 +/- 0.55 years were asked to perform a 10-minute stepping exercise where the dominant leg worked eccentrically and the non-dominant leg worked concentrically at a rate of 15 cycles/min. The quadriceps isokinetic peak torque and the corresponding peak torque angle at angular velocity of 60 degrees /sec, and muscle soreness were determined at baseline, immediately after, day 1 and day 2 after the exercise protocol. Repeated measures of ANOVA showed no change in the peak torque after the eccentric exercise and concentric exercise (p > 0.05). There was a significant shift in the peak torque angle to longer muscle lengths in the eccentrically-exercised leg immediately (65.6 +/- 2.21 degrees ) and on the following two days after exercise (day 1: 68.3 +/- 2.71 degrees ; day 2: 67.4 +/- 2.51 degrees ) when compared with baseline (61.4 +/- 1.55 degrees , p < 0.05). These features were not observed in the concentrically-exercised leg. Eccentric exercise produced a higher level of soreness than concentric exercise at day 1 and 2 after the protocol. Submaximal eccentric exercise could bring about changes in the muscle properties resulting in a shift in the angle-torque relationship to longer muscle length without significant force deficit.

Height and the risk of gestational diabetes: variations by race/ethnicity

AIMS

Gestational diabetes is a common pregnancy complication affecting races/ethnicities disproportionally. Adult height, an indicator of both genetic and early-life factors, is inconsistently associated with gestational diabetes risk. We examined the association and whether it varies by races in a nationally representative US cohort.

METHODS

Analyses were conducted among 135 861 pregnancies in the Consortium on Safe Labor, 5567 of which were diagnosed with gestational diabetes based on medical records review. Generalized estimating equations were used to estimate odds ratios (95% confidence intervals) of gestational diabetes, controlling for other risk factors including body weight. Additionally, a meta-analysis of 15 761 pregnancies with gestational diabetes and 205 828 without gestational diabetes was conducted to estimate the pooled mean difference in height between those with gestational diabetes and control subjects.

RESULTS

Height was inversely associated with gestational diabetes risk across races/ethnicities, with the strongest association among Asians (P for interaction < 0.01). Comparing extreme quartiles (> 168 vs. < 157 cm), adjusted odds ratios (95% confidence intervals) were 0.18 (0.09-0.36) for Asians/Pacific Islanders, 0.33 (0.29-0.38) for non-Hispanic white women, 0.39 (0.31-0.51) for Hispanics and 0.59 (0.47-0.75) for non-Hispanic black women. Meta-analysis found women with gestational diabetes to be significantly shorter than others.

CONCLUSIONS

Taller women are at lower risk of developing gestational diabetes, with the magnitude of association varying significantly across races/ethnicities.

A randomized study of olanzapine-containing versus standard antiemetic regimens for the prevention of chemotherapy-induced nausea and vomiting in Chinese breast cancer patients

OBJECTIVES

Chemotherapy-induced nausea and vomiting (CINV) are distressing symptoms. This randomized study evaluated the antiemetic efficacies of standard antiemetic regimen with/without olanzapine.

PATIENTS AND METHODS

Eligible patients were chemotherapy-naive Chinese breast cancer patients who were planned for (neo)adjuvant doxorubicin/cyclophosphamide. Antiemetic regimen for all studied population included aprepitant, ondansetron and dexamethasone; patients were randomized to Olanzapine (with olanzapine) or Standard arms (without olanzapine). Patients filled in self-reported diaries and completed visual analogue scales for nausea, as well as Functional Living Index-Emesis questionnaires. Blood profiles including fasting glucose and lipids were monitored.

RESULTS

120 patients were randomized. In Cycle 1 doxorubicin/cyclophosphamide, the Olanzapine arm had significantly higher rates of "Complete Response" than the Standard arm: 65.0% vs 38.3% in the overall period (p = 0.0035), 70.0% vs 51.7% in the acute period (p = 0.0397) and 92.9% vs 74.2% in the delayed period (p = 0.0254). Olanzapine arm also had significantly higher rates of "No significant nausea" and "No nausea" during all 3 time-frames and better QOL. Similar findings were also revealed throughout multiple cycles. Pre-study abnormalities in glucose and lipids occurred in 39.7% and 34.2% of the studied population respectively; there were no differences in these parameters between the two arms at end-of-study assessment.

CONCLUSION

The addition of olanzapine to standard aprepitant-based antiemetic regimen provides clinically meaningful improvement in controlling CINV. This was associated with a positive impact on QOL and tolerable toxicity profiles among Chinese breast cancer patients receiving doxorubicin/cyclophosphamide chemotherapy. Further studies on metabolic profiles of breast cancer patients are warranted.

Self-perceived exertion level and objective evaluation of neuromuscular fatigue in a training session of orchestral violin players

The aim of the study was to investigate the self-perceived exertion level and an objective measurement of muscle fatigue on violin players before and after a training session. Fourteen professional violin players volunteered in this study. Surveillance study was used to investigate the demographic characteristics, instrument playing background, playing habits variables and factors associated with playing-related musculoskeletal complaints (PRMCs). The subjective rating of the training-induced exertion was evaluated by the Borg scale ratings of perceived exertion (RPE). Surface electromyography (EMG) was used to record the fatigue level of the upper trapezius muscles before and after a training session. Medium frequency (MF) of the EMG signals was used to document the fatigue rate of this muscle. Descriptive statistics revealed a 79% prevalence rate of PRMCs with neck and shoulder region accounting for 57.1% of the areas reported. On the self-perceived exertion level associated with the training session, results indicated a significant increase in fatigue level (p = 0.003) after the training session. Regression analysis and paired samples t-tests revealed no significant difference in the slopes of MF on both sides of trapezius muscle, before and after the training sessions. The disparity in the subjective perception with the objective findings indicated that the violinists' self-perceived exertion arises from multiple sources. The high prevalence of PRMCs in this profession warrants further ergonomic investigation of possible work-related risk factors.

Kibdelins (AAD-609), novel glycopeptide antibiotics. II. Isolation, purification and structure

A new glycopeptide antibiotic complex was isolated from the fermentation culture of Kibdelosporangium aridum subsp. largum (SK&F AAD-609) by affinity chromatography on a D-alanyl-D-alanine agarose column. This major components of the complex were resolved by preparative reversed-phase HPLC. Mild acid hydrolysis showed that the new antibiotics have the same mannosyl aglycon (2) as the aridicins. FAB mass spectrometry, isoelectric focusing, potentiometric titration and carbohydrate and fatty acid analyses were used to determine the structures of the five major components of the complex. These studies showed that the kibdelins differ from the aridicins only in the oxidation level at the C-6 position of the amino sugar. Kibdelin A (5), B (6), C1 (7), C2 (8) and D (9) are a series of N-acylglucosamine analogs containing saturated straight and branched chain C10-C12 fatty acids whereas, in kibdelin D the fatty acid component is (Z)-4-decenoic acid.

Challenges of tracheostomy in COVID-19 patients in a tertiary centre in inner city London

The rapid global spread of SARS-CoV-2, the causative agent of COVID-19, has dominated healthcare services, with exponential numbers requiring mechanical ventilation in the intensive care unit (ICU). Tracheostomy facilitates respiratory and sedative weaning but risks potential viral transmission. This study reviewed the tracheostomy provision, techniques, and outcomes for a single-centre prospective cohort during the resource-pressured COVID-19 period. Seventy-two of 176 patients underwent tracheostomy at a median 17 days: 44 surgical (open), 28 percutaneous. Their median age was 58 years, the male to female ratio was 2.4:1, 75.1% were of BAME backgrounds, 76% had a BMI≥25kg/m2, and 65% had ≥2 major co-morbidities. Seventy-nine percent of patients were weaned from sedation at a median 2 days, 61% were weaned from mechanical ventilation at a median 10 days, 39% were discharged from the ICU at a median 11.5 days, and 19.4% were discharged home at a median 24 days. All patients survived the procedure. The mortality rate was 9.7% at a median 12 days. No clinician reported COVID-19 symptoms within 14 days of the procedure. The role of tracheostomy in COVID-19 is currently unclear. Delivery of tracheostomy by maxillofacial surgeons relieved the workload pressure from ICU clinicians. The choice of technique was influenced by the patient and resource factors, resulting in a mixed cohort of open and percutaneous tracheostomy in COVID-19 patients. Preliminary data suggest that open tracheostomy is as favourable as percutaneous tracheostomy for COVID-19 patients, and is safe for clinicians.

The influence of 2020 coronavirus lockdown on presentation of oral and maxillofacial trauma to a central London hospital

The novel coronavirus COVID-19 was first identified in China in December 2019. Its spread resulted in a pandemic, with the United Kingdom entering a period of national lockdown on 23 March 2020 to reduce disease burden on the National Health Service (NHS). King's College Hospital is a Major Trauma Centre serving an inner-city population of 700,000 with 120,000 patients attending the emergency department (ED) annually. We aimed to determine the effect of lockdown on OMFS trauma presentations and lessons learned from emergency service provision during a pandemic. All referrals to the oral and maxillofacial surgical (OMFS) team from ED during the first six weeks of the lockdown period - 23 March 2020 - 3 May 2020 - were compared with the same six-week period in 2019. A total of 111 referrals were made to OMFS during the first six weeks of the lockdown period in 2020 compared with 380 referrals in 2019. Of these, 50.5%, (n=192) were related to facial trauma in 2019 vs (63.1%, n=70) in 2020. Fewer patients were admitted under OMFS: 17.4% (n=35) in 2019 vs 2.9% (n=2) in 2020, and a greater number of patients were discharged from OMFS care directly from the ED: 63.2% (n=127) in 2019 vs 82.9% (n=58) in 2020. There was profound effect of the lockdown on referrals to OMFS from the ED, in number and type of diagnosis. This is potentially reflective of the increased availability of acute/emergency dental services in South-East London during the lockdown period. This gives us valuable insight for service planning in the event of further restrictions.