Socio-cultural similarity with host population rather than ecological similarity predicts success and failure of human migrations

Demographers argue that human migration patterns are shaped by people moving to better environments. More recently, however, evolutionary theorists have argued that people move to similar environments to which they are culturally adapted. While previous studies analysing which factors affect migration patterns have focused almost exclusively on successful migrations, here we take advantage of a natural experiment during World War II in which an entire population was forcibly displaced but were then allowed to return home to compare successful with unsuccessful migrations. We test two competing hypotheses: (1) individuals who relocate to environments that are superior to their place of origin will be more likely to remain-The Better Environment Hypothesis or (2) individuals who relocate to environments that are similar to their place of origin will be more likely to remain-The Similar Environment Hypothesis. Using detailed records recording the social, cultural, linguistic and ecological conditions of the origin and destination locations, we find that cultural similarity (e.g. linguistic similarity and marrying within one's own minority ethnic group)-rather than ecological differences-are the best predictors of successful migrations. These results suggest that social relationships, empowered by cultural similarity with the host population, play a critical role in successful migrations and provide limited support for the similar environment hypothesis. Overall, these results demonstrate the importance of comparing unsuccessful with successful migrations in efforts understand the engines of human dispersal and suggest that the primary obstacles to human migrations and successful range expansion are sociocultural rather than ecological.

5192Management and outcomes of patients with unstable angina with undetectable, normal, or intermediate hsTnT levels - A RAPID CPU substudy

Background

Patients with unstable angina (UA) are regarded to be at low risk for future coronary events. Guidelines discourage routine coronary angiography and recommend early discharge after individualized risk stratification. The relative value of clinical risk indicators as compared to cardiac troponin (cTn) alone is unsettled in the era of high-sensitivity cardiac troponin (hsTn) assays.

Purpose

We aimed to investigate the clinical characteristics, therapies and outcomes of UA patients with different hsTnT concentrations.

Methods

During 12 months, 2,525 patients were enrolled. UA was defined as unstable symptoms and either undetectable (<5 ng/L), normal (5–14 ng/L) or stable elevated hsTnT (15–51 ng/L). Follow up for 1-year mortality was available in 98.7%.

Results

A total of 280 patients (11.1%) received a diagnosis of UA. Mortality rates at 12 months were 0%, 1.9% and 6.9% in presence of undetectable, normal and stable elevated hsTnT. Elevated hsTnT >99th percentile but not unstable symptoms carried an independent 3.25-fold (1.78–5.93) higher risk for all-cause death after adjustment for other clinical risk indicators or the GRACE score. Utilization of guideline recommended therapies was high albeit lower than for non-ST-elevation myocardial infarction (NSTEMI). Significantly fewer patients with UA received dual antiplatelet therapy (DAPT, odds ratio (OR): 0.51 [95% CI: 0.44–0.59], p<0.0001), coronary angiography (CA, OR 0.79, [95% CI: 0.74–0.87], p<0.0001), and percutaneous coronary intervention (PCI, OR 0.50, [95% CI: 0.40–0.61], p<0.0001), compared to NSTEMI. However, prevalence of significant obstructive coronary artery disease (CAD) requiring PCI was 31.8%, even in patients with undetectable hsTnT, indicating the need for stress testing.

Conclusions

The current dichotomization of patients into UA and NSTEMI is no longer appropriate. Additional risk stratification seems warranted including the presence and magnitude of hsTn concentration and additional risk indicators.

Acknowledgement/Funding

Research Grant by Roche Diagnostics

3302Effects of implementation of the ESC 0/1-hour algorithm on efficiacy and safety of discharge after rule-out in a consecutive cohort of patients with suspected acute coronary syndrome - RAPID-CPU study

Aims

The feasibility, efficacy and safety of ESC 0/1- and 0/3-hour algorithms using high-sensitivity troponin T (hsTnT) were evaluated in an all-comer cohort with suspected acute coronary syndrome, based on a broad spectrum of symptoms.

Methods

During 12 months, 2,525 eligible patients were enrolled. In a pre-implementation period of 6 months, prevalence of protocols, disposition, lengths of emergency department (ED) stay and treatments were registered. Implementation of ESC 0/1-hour protocol was monitored for another 6 months. Primary endpoints comprised the change of diagnostic protocols, and all-cause mortality at 30 days following direct discharge from the ED. Secondary endpoints included length of ED stay, hospital discharge, and 1-year mortality.

Results

Use of the ESC 0/1-hour algorithm increased by 270% at the cost of the standard 0/3-hour protocol. Median follow-up times were 400 (316–459) days, with vital status available for 98.7%. After rule-out (1,588 patients), 1,309 patients (76.1%) were discharged directly from the ED, with an all-cause mortality of 0.08% at 30 days (1 death due to lung cancer). Median lengths of stay were 2.9 (1.9–3.8) and 3.2 (2.7–4.4) hours using a single hsTnT below limit of detection (LoD) (5 ng/L) at presentation and the ESC 0/1-hour algorithm, respectively, as compared to 5.3 (4.7–6.5) hours using the ESC 0/3-hour rule-out protocol. Discharge rates increased from 53.9% to 62.8% (p<0.0001), without excessive use of diagnostic resources within 30 days.

Mortality by diagnostic rule

Conclusion

Implementation of the ESC 0/1-hour algorithm seems feasible and safe. It is associated with shorter ED stays than the ESC 0/3-hour protocol and a further increase of discharge rates.

Acknowledgement/Funding

Roche Diagnostics International Ltd.

Outcome of Stable Patients With Acute Myocardial Infarction and Coronary Artery Bypass Surgery Within 48 Hours: A Single-Center, Retrospective Experience

Background

The optimal timing of coronary artery bypass grafting (CABG) in clinically stable patients with acute myocardial infarction who are unsuitable for percutaneous coronary intervention is unclear. We report our experience with early CABG in these patients.

Methods and Results

Between January 2001 and May 2015, 766 patients with ST‐segment–elevation myocardial infarction (STEMI, n=305) or non‐STEMI (NSTEMI, n=461) not including cardiogenic shock underwent CABG within 48 hours at our department. STEMI patients were younger than non‐STEMI patients (age 65 years [range: 58–72] versus 70 years [range: 62–75], P<0.001) with a lower EuroSCORE II (4.12 [range: 2.75–5.81] versus 4.58 [range: 2.80–7.74], P=0.009). STEMI patients had undergone preoperative percutaneous coronary intervention more often (20.3% versus 7.8%, P<0.001). Time to surgery was shorter in STEMI compared with non‐STEMI patients (5.0 hours [range: 3.2–8.8] versus 11.7 hours [range: 6.4–22.0], P<0.001). No significant differences concerning arterial graft use (93.8% versus 94.8%, P=0.540) or complete revascularization (87.5% versus 83.4%, P=0.121) were observed. The rate of strokes did not differ between the groups (2.0% versus 3.9%, P=0.134). Thirty‐day mortality was lower in STEMI patients (2.7% versus 6.6% P=0.018), especially when CABG was performed within 6 hours (1.8% versus 7.1%, P=0.041). Survival of STEMI and non‐STEMI patients was 94% versus 88% after 1 year (P<0.001), 87% versus 73% after 5 years (P<0.001), and 74% versus 57% after 10 years (P<0.001). Independent predictors of 30‐day and long‐term mortality included preoperatively increased lactate values, age, atrial fibrillation, and reduced left ventricular function.

Conclusions

Stable STEMI patients showed a lower rate of perioperative complications and better survival compared with non‐STEMI patients when CABG was performed within 48 hours.

Lattice symmetries and the topologically protected transport of colloidal particles

The topologically protected transport of colloidal particles on top of periodic magnetic patterns is studied experimentally, theoretically, and with computer simulations. To uncover the interplay between topology and symmetry we use patterns of all possible two dimensional magnetic point group symmetries with equal lengths lattice vectors. Transport of colloids is achieved by modulating the potential with external, homogeneous but time dependent magnetic fields. The modulation loops can be classified into topologically distinct classes. All loops falling into the same class cause motion in the same direction, making the transport robust against internal and external perturbations. We show that the lattice symmetry has a profound influence on the transport modes, the accessibility of transport networks, and the individual transport directions of paramagnetic and diamagnetic colloidal particles. We show how the transport of colloidal particles above a two fold symmetric stripe pattern changes from universal adiabatic transport at large elevations via a topologically protected ratchet motion at intermediate elevations toward a non-transport regime at low elevations. Transport above four-fold symmetric patterns is closely related to the two-fold symmetric case. The three-fold symmetric case however consists of a whole family of patterns that continuously vary with a phase variable. We show how this family can be divided into two topologically distinct classes supporting different transport modes and being protected by proper and improper six fold symmetries. We discuss and experimentally demonstrate the topological transition between both classes. All three-fold symmetric patterns support independent transport directions of paramagnetic and diamagnetic particles. The similarities and the differences in the lattice symmetry protected transport of classical over-damped colloidal particles versus the topologically protected transport in quantum mechanical systems are emphasized.

Defect Dynamics in Artificial Colloidal Ice: Real-Time Observation, Manipulation, and Logic Gate

We study the defect dynamics in a colloidal spin ice system realized by filling a square lattice of topographic double well islands with repulsively interacting magnetic colloids. We focus on the contraction of defects in the ground state, and contraction or expansion in a metastable biased state. Combining real-time experiments with simulations, we prove that these defects behave like emergent topological monopoles obeying a Coulomb law with an additional line tension. We further show how to realize a completely resettable "nor" gate, which provides guidelines for fabrication of nanoscale logic devices based on the motion of topological magnetic monopoles.

Topological protection of multiparticle dissipative transport

Topological protection allows robust transport of localized phenomena such as quantum information, solitons and dislocations. The transport can be either dissipative or non-dissipative. Here, we experimentally demonstrate and theoretically explain the topologically protected dissipative motion of colloidal particles above a periodic hexagonal magnetic pattern. By driving the system with periodic modulation loops of an external and spatially homogeneous magnetic field, we achieve total control over the motion of diamagnetic and paramagnetic colloids. We can transport simultaneously and independently each type of colloid along any of the six crystallographic directions of the pattern via adiabatic or deterministic ratchet motion. Both types of motion are topologically protected. As an application, we implement an automatic topologically protected quality control of a chemical reaction between functionalized colloids. Our results are relevant to other systems with the same symmetry.

Transport of a collection of classical particles involves thermal ratchet effect or adiabatic motion, which brings complexity to control multiparticle transport. Here, Loehr et al. show topologically protected multiparticle transport of diamagnetic and paramagnetic colloids, driven by periodic modulation loops of an external magnetic field.

Magnetic guidance of the magnetotactic bacterium Magnetospirillum gryphiswaldense

Magnetospirillum gryphiswaldense is a magnetotactic bacterium with a permanent magnetic moment capable of swimming using two bipolarly located flagella. In their natural environment these bacteria swim along the field lines of the homogeneous geomagnetic field in a typical run and reversal pattern and thereby create non-differentiable trajectories with sharp edges. In the current work we nevertheless achieve stable guidance along curved lines of mechanical instability by using a heterogeneous magnetic field of a garnet film. The successful guidance of the bacteria depends on the right balance between motility and the magnetic moment of the magnetosome chain.

Pigmented villo-nodular synovitis and giant-cell tumor of tendon sheaths: a binational retrospective study

AIM

Pigmented villonodular synovitis is rare. Thus, we initiated a retrospective multi-center study regarding symptoms, location, type of disease, type of surgery, number of recurrences, use of adjuvant therapies and functional outcome.

RESULTS

Ten centers contributed. Data from 173 patients were sampled. The disease was seen predominantly in joints, less frequently in tendon sheaths and bursae. Patients with articular lesions suffered mainly from the diffuse type. In tendon sheaths, the relation "diffuse versus nodular" was nearly 50 % each, in bursae most often the nodular type was found. Anatomically, mostly the knee was affected. Institutions with more than 20 patients had a lower rate of recurrence than those with less than 20 cases. Regarding the knee, there were less recurrences in joints treated with open synovectomy than in those treated arthroscopically.

CONCLUSIONS

Since the rate of recurrence has been rather high, the use of adjuvant treatments (radiosynoviorthesis or radiotherapy) is recommended. In our study, the rate of their application was quite low. Patients who received an adjuvant therapy after primary surgery did not show any recurrence. In 14 % of patients in whom an adjuvant therapy had been used, after at least one recurrence, further recurrences were observed. Functional results were excellent in 84 % of patients.

LEVEL OF EVIDENCE

Prognostic multi-center study, Level III.

MC1R variants correlate with thinhorn sheep colour cline but not individual colour

The melanocortin 1 receptor (MC1R) gene has provided a window on the evolution of colour polymorphisms. Recent studies have demonstrated associations between MC1R and melanism in a number of wildlife species. Thinhorn sheep ( Ovis dalli Nelson, 1884) are a possible species to test for association between MC1R polymorphisms and melanism. Across their range the pelage colour of thinhorn sheep intergrades between all white phenotypes to very dark phenotypes. Most thinhorn sheep are white; however, there is a 1200 km cline from light to dark sheep that occurs over three genetically distinct polymorphic populations. We sequenced the entire MC1R gene from 40 individuals across the range of thinhorn sheep. We found a single nucleotide polymorphism in MC1R at base pair position 921 that coincided with the geographic cline. However, at the individual level we found no relationship between individual melanism and genotype.

The utility of the general practice research database to examine selected congenital heart defects: a validation study

OBJECTIVE

The purpose of this research was (1) to validate that ventricular septal defect (VSD), tetralogy of Fallot (TOF), and coarctation of the aorta (COA) can be studied in the UK General practice research database (GPRD) and (2) to understand which of the available GPRD components (computerized medical records, questionnaires, and maternal/infant free text) provide maximal information about these heart defects.

METHODS

Using a practitioner questionnaire, the positive predictive value (PPV) of the computerized medical record for VSD, TOF, and COA were determined. Both infant and maternal free text was examined. Concordance between the infant free text information and questionnaires was calculated. The proportion of infant information captured in the maternal free text was determined.

RESULTS

A 93% response rate was achieved. Based on questionnaire responses, an overall PPV of 93.5% was achieved (VSD = 95%, TOF = 90%, COA = 100%). Approximately half of the records contained infant free text information including information on the type and size of VSD, echocardiogram findings, and surgery. Concordance between the infant's free text and questionnaire information occurred in most of the cases (92-100%). The proportion of infant information in the maternal free text was low (4-19%).

CONCLUSION

The GPRD computerized medical records are sufficient to assess VSD, TOF, and COA. This study confirms that maternal free text provides a low yield of limited information pertaining to the infants' defect, while the infant free text may provide an additional information usually obtainable from practitioner questionnaires. The information provided by an infant free text may limit the need for practitioner questionnaire validation.

Horn growth rate and longevity: implications for natural and artificial selection in thinhorn sheep (Ovis dalli)

We used horn measurements from natural and hunted mortalities of male thinhorn sheep Ovis dalli from Yukon Territory, Canada, to examine the relationship between rapid growth early in life and longevity. We found that rapid growth was associated with reduced longevity for sheep aged 5 years and older for both the hunted and natural mortality data sets. The negative relationship between growth rate and longevity in hunted sheep can at least partially be explained by morphologically biased hunting regulations. The same trend was evident from natural mortalities from populations that were not hunted or underwent very limited hunting, suggesting a naturally imposed mortality cost directly or indirectly associated with rapid growth. Age and growth rate were both positively associated with horn size at death for both data sets, however of the two growth rate appeared to be a better predictor. Large horn size can be achieved both by individuals that grow horns rapidly and by those that have greater longevity, and the trade-off between growth rate and longevity could limit horn size evolution in this species. The similarity in the relationship between growth rate and longevity for hunted and natural mortalities suggests that horn growth rate should not respond to artificial selection. Our study highlights the need for the existence and study of protected populations to properly assess the impacts of selective harvesting.

Evidence for cryptic glacial refugia from North American mountain sheep mitochondrial DNA

The separation of populations by ice sheets into large refugia can account for much of the genetic diversity found in present day populations. The evolutionary implications of small glacial refugia have not been as thoroughly explored. To examine refugial origins of North American mountain sheep Ovis spp., we analyzed a 604 bp portion of the mitochondrial DNA (mtDNA) control region from 223 O. dalli and O. canadensis. Major refugia were identified in eastern Beringia and southern North America, and we found evidence for two smaller refugia situated between the Laurentide and Cordilleran glaciers. Our results are the first to demonstrate support for survival of any organism in the latter two refugia. These refugia also appear to have conserved a genetic signal that confirms past hybridization of O. dalli and O. canadensis.

The Sony Ericsson WTA Tour 10 year age eligibility and professional development review

Concerns have long existed over the participation of adolescent athletes in professional sports. In 2004, the Sony Ericsson WTA Tour (WTA Tour) commissioned a Professional Development Advisory Panel (PDAP) to evaluate the WTA Tour's age eligibility rule (AER) and professional development programmes (PDPs) for female tennis players since their inception in 1995. More than 75% of the 628 respondents supported the principles of the AER, and 90% indicated a need for PDPs. Statistical analysis of WTA Tour players' careers found that premature retirements (players leaving the Tour at or before age 21) decreased significantly from 7% before the AER to less than 1% afterward, and median career length increased by 43%. The PDAP recommends that the WTA Tour continues a phased-in, developmentally appropriate AER, enhances the PDPs, and works with other sport governing bodies to coordinate rules and programmes at earlier ages to aid the transition of adolescents into adult sports.

Gender- and age-class-specific reactions to human disturbance in a sexually dimorphic ungulate

According to optimality theory, an individual's characteristics should play a major part in determining antipredator strategies. We studied behavioural reactions to human presence of gender and age classes of 35 thinhorn sheep (Ovis dalli Nelson, 1884) in late winter 2001 in Faro, Yukon Territory, Canada. The behaviour of undisturbed sheep was observed from distances of 400–1200 m and compared with the behaviour recorded when one or two people were in close proximity to the sheep. Ewes decreased bedding and increased foraging when humans were present, but there were no changes in these behaviours in rams. Disturbance caused an increase in vigilance and a trend was found for adults to react more strongly to disturbance than juveniles. We demonstrate the importance for disturbance research of gaining detailed information about all different kinds of population members and using applicable statistical tests in the data analyses.

The making of a corporate athlete

Management theorists have long sought to identify precisely what makes some people flourish under pressure and others fold. But they have come up with only partial answers: rich material rewards, the right culture, management by objectives. The problem with most approaches is that they deal with people only from the neck up, connecting high performance primarily with cognitive capacity. Authors Loehr and Schwartz argue that a successful approach to sustained high performance must consider the person as a whole. Executives are, in effect, "corporate athletes." If they are to perform at high levels over the long haul, they must train in the systematic, multilevel way that athletes do. Rooted in two decades of work with world-class atheletes, the integrated theory of performance management addresses the body, the emotions, the mind, and the spirit through a model the authors call the performance pyramid. At its foundation is physical well-being. Above that rest emotional health, then mental acuity, and, finally, a spiritual purpose. Each level profoundly influences the others, and all must be addressed together to avoid compromising performance. Rigorous exercise, for instance, can produce a sense of emotional well-being, clearing the way for peak mental performance. Rituals that promote oscillation--the rhythmic expenditure and recovery of energy-link the levels of the pyramid and lead to the ideal performance state. The authors offer case studies of executives who have used the model to increase professional performance and improve the quality of their lives. In a corporate environment that is changing at warp speed, performing consistently at high levels is more necessary than ever. Companies can't afford to address employees' cognitive capacities while ignoring their physical, emotional, and spiritual well-being.

Alpine and cross-country skiing after total hip replacement: 2 cohorts of 50 patients each, one active, the other inactive in skiing, followed for 5-10 years

2 groups of 50 patients each, matched for age, weight, height, gender and type of implant, were clinically and radiographically examined after THR. Group A regularly carried out alpine skiing and/or cross-country skiing, while group B did no winter sports. At 5 years, no signs of loosening were found in group A, whereas 5/60 implants in group B had signs of loosening, mostly of the femoral component (p < 0.05). At 10 years, 30 patients remained in group A and 27 in group B. No new cases of loosening were found in group B, but 2/30 cases in group A. There was a higher (p < 0.05) average wear rate in group A (2.1 mm) than in group B (1.5 mm). The wear rate was particularly high (3-4 mm) in physically very active patients in group A with localized osteolysis at the interface. It seems likely that in an even longer follow-up, the number of cases of aseptic loosening would be greater in group A than group B. Our findings, combined with the results of previously-published biomechanical studies, do not provide any evidence that controlled alpine and/ or cross-country skiing has a negative effect on the acetabular or femoral component of hip replacements. The results of the biomechanical studies indicate, however, that it is advantageous to avoid short-radius turns on steep slopes or moguls.

Issues of sexuality in older women

The aim of this exploratory research study was to investigate the attitudes of women over 60 toward sexuality and intimacy, to elicit which issues concerning sexuality and intimacy are important to them, and to gather their perceptions of how issues of sexuality and intimacy are addressed by the medical profession. Fourteen women aged 60-85 participated in three focus group interviews organized in Kingston, Ontario, Canada. We qualitatively measured recurring themes in attitudes about sexuality. Although they grew up in a generation when sex and sexuality were rarely discussed, these older women did not have any problem talking about sex, sexuality, and their attitudes towards these topics within the focus group setting. The participants felt on the whole, that sexuality is, and will continue to be, an important part of their lives. There was consensus that they would feel comfortable talking to their family doctor about their own or their partner's problems if asked but might not volunteer the information. Sex and sexuality are important issues to these older women. Male impotence is the most common problem that affects these older women's sex lives. They need more information about normal changes with aging that affect sexuality of older women and men. These women have rarely been afforded the opportunity to discuss sexuality with their physician. The small sample size of this pilot study provided useful information but is not definitive in its conclusions. Further research is needed to determine physician attitudes and practices concerning sex and sexuality in this age group.

Levels of the mitochondrial endonuclease during rat cardiac development implicate a role for the enzyme in repair of oxidative damage in mitochondrial DNA

Mammalian heart mitochondria (MT) contain a potent Mg(2+)-dependent DNA endonuclease that becomes soluble once isolated mitochondria are disrupted using detergent. The level of this endonuclease was previously found to be markedly elevated in adult rat heart compared to other adult rat tissues. Among tissues, the level of the MT endonuclease does not appear to be correlated with the rate of MT DNA replication but rather with the rate of oxidative metabolism [Houmiel, K.L., Gerschenson, M. and Low, R.L., 1991. Biochimica Biophysica Acta 1079: 197-202]. In the present study, the level of the endonuclease has been quantitated both during rat cardiac development, from gestational day 18 through adulthood, and in cultured rat heart myoblasts. Surprisingly, the specific activity of the MT endonuclease in fetal and newborn mitochondria is high. The values are greater than 50% of that seen in the adult even though the mitochondria at this period of heart development are few and structurally disorganized. Remarkably, there is a burst of endonuclease activity at day 2 which accompanies a similar, transient elevation of respiratory complex I and IV activities. At later times, the endonuclease activity gradually increases until adulthood and correlates with steady increases in MT DNA and DNA polymerase-gamma. In cultured myoblasts, the level of the endonuclease increases about seven-fold as the growing cells reach confluency and differentiate into myotubes. These variations in the specific activity of the endonuclease, when considered along with other properties of the enzyme suggest that the endonuclease may serve a role in the removal of oxidative damage in MT DNA incurred from respiration.

Isolated dislocation of the radial head

Fifty-four patients (12 bilateral) with isolated dislocations of the radial head were encountered over a 20-year period. The congenital varieties (26 patients) included isolated unilateral, familial, synostosis-related, and syndrome-related. The acquired types (28 patients) involved trauma, neuromuscular impairment, or adaptive dislodgments. Acute, traumatic dislocation (17 patients) was the most common presentation. Others were diagnosed incidentally, or associated with discomfort, dysfunction, or deformity. Closed reduction of an acute traumatic dislocation was generally successful (16 of 17 patients). Realignment attempts (three cases) on late diagnosed traumatic cases and isolated congenital types were invariably unsuccessful, eventually requiring radial head excision. Four patients underwent excision of the head of the radius as primary treatment.

Osteoblastoma of the cervical spine. Case report

This case report demonstrates the importance of an exact workup in unclear neck pain. An osteoblastoma situated in the pedicule of C6 is described. During 36 months there was no diagnosis made. Only by a CT-scan a tumorous lesion in the pedicule of C6 with the histology of a benign osteoblastoma was found. The therapy consisted in excision of the tumor of C6. A fusion was added because important parts of the joint were involved.

[Arthroplasty of the elbow]

Elbow arthroplasty is still one of the less frequently performed joint replacement procedures. It is technically demanding, and numerous complications are possible. It is therefore indicated mainly in severely handicapped patients in whom all other alternatives have been attempted. A review of the literature relating to arthroplasties monitored over follow-up periods of more than 5 years shows that the results are now quite acceptable. They are far better than those seen following most resection arthroplasties. The results achieved with our GSB III prosthesis are compared with those obtained with other prosthetic devices in current use. It appears that in a large proportion of cases our prosthesis allows a good range of painfree motion, which we attribute in part to the operative approach used. The complication rate appears to be relatively low.

Semiconstrained elbow prostheses with special reference to the GSB III prosthesis

Fully constrained metal-to-metal elbow prostheses are not used anymore because of a high loosening rate. Today semiconstrained or condylar prostheses are the two possibilities when replacement of a destroyed elbow joint is considered. A careful analysis of the most recent publications in the world literature reveals a high complication rate for both types of prostheses, each one having specific advantages and disadvantages. The Gschwend-Scheier-Bähler (GSB) III prosthesis is a semiconstrained prosthesis, requires little bone resection, and is therefore easily salvaged. The results in regard to pain relief and improvement in range of motion are satisfactory in a high percentage of patients. The rate of lasting complications is lower than with most of the other prostheses. The authors' transtricipital approach is also a factor that contributes to the high success rate. In case of a failed arthroplasty the authors' method of reconstructing the humeral condyles allows a better salvage.

Spontaneous rupture of the quadriceps tendon and patellar ligament during treatment for chronic renal failure

The quadriceps tendon and patellar ligament rupture rarely, even when under great stress or trauma, but can rupture spontaneously in patients with chronic diseases such as gout, rheumatoid arthritis and renal disease. Several factors probably combine to weaken the tendon, including an impoverished local vascular supply, repeated microtrauma and secondary hypoparathyroidism with osteodystrophy. In the three cases reported here, one of which was bilateral, the patients were being treated for chronic renal disease; surgical repair of the tendons led to sound healing and a return to normal function of the joints.

Deoxythymidine sugars are not direct precursors of DNA-thymine

A theoretical model for the kinetics of uptake of a putative precursor molecule into nucleotide pools and into replicating DNA has been developed. The relationship between the accumulation of radioactively labeled precursors in the pool and the appearance of radioactivity in DNA is then derived. Experiments have been carried out in bacteria to compare the uptake of radioactive thymine into deoxythymidine triphosphate, deoxythymidine diphosphate sugars, and DNA to test the suitability of either compound as the direct precursor of thymine in DNA. New one-dimensional, thin-layer chromatographic procedures were used to determine the specific activity of deoxythymidine triphosphate and deoxythymidine triphosphate and deoxythymidine diphosphate sugars in growing cultures of 32PO4-labeled Escherichia coli during pulse labeling with [3H]-thymine. A comparison of the experimental data with our theoretical model supports the hypothesis that deoxythymidine triphosphate, but not deoxythymidine sugar, is the direct precursor of thymine in normally replicating DNA in vivo.