Increased use of computed tomography in Denmark: stage shift toward early stage lung cancer through incidental findings

BACKGROUND

Computed tomography (CT) examinations are increasingly used worldwide and incidental findings are growing likewise. Lung cancer stage at diagnosis is pivotal to survival. The earliest stage of lung cancer, stage IA is in most cases asymptomatic. Potentially, increased use of clinical CTs could induce a stage shift toward earlier lung cancer diagnosis.

MATERIALS AND METHODS

Data on the number of CT thorax in Denmark and the stage distribution of Danish lung cancer patients 2013-2020 were acquired from, respectively, the Danish Health Data Authority and the Danish Lung Cancer Registry. Clinical auditing of stage IA lung cancer patients was performed in the period 2019-2021 in a Danish region to assess the reasons for referral. Auditing of stage IV lung cancer patients was done to see whether a CT thorax was performed in a two-year period before diagnosis.

RESULTS

All regions showed an increase in CTs per 1000 inhabitants. However, the number of CTs performed in 2013 differed by more than 50% among regions, and the increase per year also differed, from an increase of 1.9 to 3.4 more examinations per year. A significant correlation between CTs and fraction of stage IA lung cancers was seen in four out of the five regions. The audit of stage IA lung cancer cases revealed that 86.8% were incidental findings. Audit of stage IV lung cancer found that 4.3% had a nodule/infiltrate on a previous CT within a 2-year period prior to the diagnosis of lung cancer that was the probable origin of stage IV lung cancer.

CONCLUSION

The study found that the vast majority of early-stage lung cancers were incidental findings. It highlights that follow-up algorithms of incidental findings should be used in accordance with guidelines and it should be unequivocally how the CT follow-up of pulmonary infiltrates is managed.

Work-related stressors, depression and quality of life in Danish managers

Background

By use of valid questionnaires to investigate work-related stress and distress in Danish managers.

Methods

The survey focused on members of the Danish Association of Managers and Executives who no longer were active (formermanagers' group). Acting managers (active managers' group) served as controls. Questionnaires measuring stressors at work and general life events were used. For the measurement of distress, scales for depression and quality of life were used.

Results

The Mokken analysis proved the validity of the questionnaires, i.e. their summed-up total scores were sufficient statistics. No differences were found between former (n = 1256) and active managers (n = 942) as to life events. Approximately 20% of former managers were at risk of depression and 12% had developed major depression. Among the specific work-related stressors were role overload, lack of team spirit and lack of social support. The percentage of active managers at risk of or suffering from major depression did not differ significantly from the Danish general population. Approximately 37% of the former managers had a decreased well-being. Alcohol use was found to be significantly associated with depression.

Conclusions

The study identified specific work-related stressors in managers, 12% of whom developed a major depression.

Topoisomerase I activity and sensitivity to camptothecin in breast cancer-derived cells: a comparative study

Background

Camptothecin (CPT) and its derivatives are currently used as second- or third-line treatment for patients with endocrine-resistant breast cancer (BC). These drugs convert nuclear enzyme DNA topoisomerase I (TOP1) to a cell poison with the potential to damage DNA by increasing the half-life of TOP1-DNA cleavage complexes (TOP1cc), ultimately resulting in cell death. In small and non-randomized trials for BC, researchers have observed extensive variation in CPT response rates, ranging from 14 to 64%. This variability may be due to the absence of reliable selective parameters for patient stratification. BC cell lines may serve as feasible models for generation of functional criteria that may be used to predict drug sensitivity for patient stratification and, thus, lead to more appropriate applications of CPT in clinical trials. However, no study published to date has included a comparison of multiple relevant parameters and CPT response across cell lines corresponding to specific BC subtypes.

Method

We evaluated the levels and possible associations of seven parameters including the status of the TOP1 gene (i.e. amplification), TOP1 protein expression level, TOP1 activity and CPT susceptibility, activity of the tyrosyl-DNA phosphodiesterase 1 (TDP1), the cellular CPT response and the cellular growth rate across a representative panel of BC cell lines, which exemplifies three major BC subtypes: Luminal, HER2 and TNBC.

Results

In all BC cell lines analyzed (without regard to subtype classification), we observed a significant overall correlation between growth rate and CPT response. In cell lines derived from Luminal and HER2 subtypes, we observed a correlation between TOP1 gene copy number, TOP1 activity, and CPT response, although the data were too limited for statistical analyses. In cell lines representing Luminal and TNBC subtypes, we observed a direct correlation between TOP1 protein abundancy and levels of enzymatic activity. In all three subtypes (Luminal, HER2, and TNBC), TOP1 exhibits approximately the same susceptibility to CPT. Of the three subtypes examined, the TNBC-like cell lines exhibited the highest CPT sensitivity and were characterized by the fastest growth rate. This indicates that breast tumors belonging to the TNBC subtype, may benefit from treatment with CPT derivatives.

Conclusion

TOP1 activity is not a marker for CPT sensitivity in breast cancer.

A new DNA sensor system for specific and quantitative detection of mycobacteria

In the current study, we describe a novel DNA sensor system for specific and quantitative detection of mycobacteria, which is the causative agent of tuberculosis. Detection is achieved by using the enzymatic activity of the mycobacterial encoded enzyme topoisomerase IA (TOP1A) as a biomarker. The presented work is the first to describe how the catalytic activities of a member of the type IA family of topoisomerases can be exploited for specific detection of bacteria. The principle for detection relies on a solid support anchored DNA substrate with dual functions namely: (1) the ability to isolate mycobacterial TOP1A from crude samples and (2) the ability to be converted into a closed DNA circle upon reaction with the isolated enzyme. The DNA circle can act as a template for rolling circle amplification generating a tandem repeat product that can be visualized at the single molecule level by fluorescent labelling. This reaction scheme ensures specific, sensitive, and quantitative detection of the mycobacteria TOP1A biomarker as demonstrated by the use of purified mycobacterial TOP1A and extracts from an array of non-mycobacteria and mycobacteria species. When combined with mycobacteriophage induced lysis as a novel way of effective yet gentle extraction of the cellular content from the model Mycobacterium smegmatis, the DNA sensor system allowed detection of mycobacteria in small volumes of cell suspensions. Moreover, it was possible to detect M. smegmatis added to human saliva. Depending on the composition of the sample, we were able to detect 0.6 or 0.9 million colony forming units (CFU) per mL of mycobacteria, which is within the range of clinically relevant infection numbers. We, therefore, believe that the presented assay, which relies on techniques that can be adapted to limited resource settings, may be the first step towards the development of a new point-of-care diagnostic test for tuberculosis.

Current-induced membrane discharge

Possible mechanisms for overlimiting current (OLC) through aqueous ion-exchange membranes (exceeding diffusion limitation) have been debated for half a century. Flows consistent with electro-osmotic instability have recently been observed in microfluidic experiments, but the existing theory neglects chemical effects and remains to be quantitatively tested. Here, we show that charge regulation and water self-ionization can lead to OLC by "current-induced membrane discharge" (CIMD), even in the absence of fluid flow, in ion-exchange membranes much thicker than the local Debye screening length. Salt depletion leads to a large electric field resulting in a local pH shift within the membrane with the effect that the membrane discharges and loses its ion selectivity. Since salt co-ions, H(+) ions, and OH(-) ions contribute to OLC, CIMD interferes with electrodialysis (salt counterion removal) but could be exploited for current-assisted ion exchange and pH control. CIMD also suppresses the extended space charge that leads to electro-osmotic instability, so it should be reconsidered in both models and experiments on OLC.

The substituted (S)-3-phenylpiperidine (−)-OSU6162 reduces apomorphine- and amphetamine-induced behaviour in Cebus apella monkeys

Low affinity dopamine (DA) D2 antagonists such as the substituted (S)-3-phenylpiperidine (-)-OSU6162 have been proposed to be putative antipsychotic agents not endowed with extrapyramidal side effects (EPS). In the present study we investigated the effects of (-)-OSU6162 on (-)-apomorphine and d-amphetamine-induced behaviours in EPS sensitised Cebus apella monkeys. (-)-OSU6162 was administered subcutaneously in doses of 1, 3, 6 and 9 mg/kg alone and in combination with (-)-apomorphine (0.25 mg/kg) or d-amphetamine (0.5 mg/kg). (-)-OSU6162 inhibited (-)-apomorphine-(1-9 mg/kg) as well as d-amphetamine (3-9 mg/kg)-induced arousal and stereotypy. EPS did not occur when (-)-OSU6162 was administered in combination with (-)-apomorphine or d-amphetamine. However, when (-)-OSU6162 was administered alone, dystonia was observed at high doses (6 and 9 mg/kg) in two out of six monkeys. The present study shows that (-)-OSU6162 can inhibit (-)-apomorphine-induced behaviours in non-human primates at doses that do not cause EPS. When (-)-OSU6162 was tested against d-amphetamine-induced behaviours a separation between dose levels that inhibit d-amphetamine effects and cause EPS was not observed. The data further substantiate a role for low affinity DA D2 antagonists in the pharmacological treatment of psychosis.

Cebus apella, a nonhuman primate highly susceptible to neuroleptic side effects, carries the GLY9 dopamine receptor D3 associated with tardive dyskinesia in humans

Tardive dyskinesia (TD) is a severe side effect of traditional neuroleptics affecting a considerable number of schizophrenic patients. Accumulating evidence suggests the existence of a genetic disposition to TD and other extra pyramidal symptoms (EPS) most strongly linked to a ser/gly polymorphism in position 9 of the D3 dopamine receptor gene (DRD3). The Cebus apella monkey is the favored animal model to study TD and other EPS because of its high susceptibility to side effects of neuroleptics. We therefore determined the sequence of the DRD3 gene in this species and compared it with that of humans. We found that the highly TD susceptible C. apella monkey (n=21) carries the gly9/gly9 DRD3 genotype that has been associated with TD in humans. Contrarily, C. apella did not carry the ser23 5HT2C allele that has been reported to increase TD susceptibility in humans.

The adenosine A2A receptor agonist CGS 21680 exhibits antipsychotic-like activity in Cebus apella monkeys

The adenosine A2A receptor agonist CGS 21680 has shown effects similar to dopamine antagonists in behavioural assays in rats predictive for antipsychotic activity, without induction of extrapyramidal side-effects (EPS). In the present study, we examined whether this functional dopamine antagonism and lack of EPS in rodents could also be observed in non-human primates. We investigated the effects of CGS 21680 on behaviours induced by D-amphetamine and (-)-apomorphine in EPS-sensitized Cebus apella monkeys. CGS 21680 was administered s.c. in doses of 0.01, 0.025 and 0.05 mg/kg, alone and in combination with D-amphetamine and (-)-apomorphine. The monkeys were videotaped after drug administration and the tapes were rated for EPS and psychosis-like symptoms. CGS 21680 decreased apomorphine-induced behavioural unrest, arousal (0.01-0.05 mg/kg) and stereotypies (0.05 mg/kg) while amphetamine-induced behaviours (unrest, stereotypies, arousal) were unaffected. EPS were not observed at any dose. At 0.05 mg/kg CGS 21680 produced vomiting. The two lower doses did not produce observable side-effects. Though the differential effect on amphetamine- and apomorphine-induced behaviours is intriguing, CGS 21680 showed a functional anti-dopaminergic effect in Cebus apella monkeys without production of EPS. This further substantiates that adenosine A2A receptor agonists may have potential as antipsychotics with atypical profiles.

Exercise and multiple sclerosis: physiological, psychological, and quality of life issues

The case for the benefits of physical activity has been well documented in healthy individuals, and the potential for reducing the risk of mental and physical ill health is substantial. Yet, individuals with multiple sclerosis (MS) have long been advised to avoid participation in exercise in order to minimise the risk of exacerbations and symptoms of fatigue. There is, however, increasing interest in how acute and chronic exercise affect physiological and psychological functioning in MS. Much of the research has examined physiological tolerance to exercise and focused on responses in terms of heart rate, blood pressure, cardiorespiratory fitness, muscle function, and symptom stability. Little research has focused on understanding how exercise affects psychosocial functioning and brings about changes in depression, affect, mood, well-being, and quality of life. This paper provides a summary of the research exploring the efficacy of physical activity for people with MS. In addition, the key issues that face clinical practice are examined, and considerations for research are discussed.

The ethical beliefs and behaviours of Victorian fitness professionals

A survey based on those employed by Petitpas, Brewer, Rivera, and Van Raalte (1994), Pope, Tabachnick, and Keith-Spiegel (1987), Pope and Vetter (1992), and Tabachnick, Keith-Spiegel, and Pope (1991) was used to investigate the ethical beliefs and behaviours of Victorian fitness professionals. Although there is evidence that Victorian fitness professionals are knowledgeable about some general ethical principles, the results of this study suggest that there is some lack of consensus among Victorian fitness professionals about the ethical appropriateness of a number of complex issues relating to business practices, confidentiality, dual relationships, and personal and professional boundaries. The findings suggest there is a need to improve the professional and ethical education of fitness professionals and to develop comprehensive ethical principles and a code of conduct that is relevant to the individuals working in the Australian fitness profession.

Direct comparison of visual cortex activation in human and non-human primates using functional magnetic resonance imaging

We report a technique for functional magnetic resonance imaging (fMRI) in an awake, co-operative, rhesus macaque (Macaca mulatta) in a conventional 1.5T clinical MR scanner, thus accomplishing the first direct comparison of activation in visual cortex between humans and non-human primates with fMRI. Activation was seen in multiple areas of striate and extra-striate visual cortex and in areas for motion, object and face recognition in the monkey and in homologous visual areas in a human volunteer. This article describes T1, T2 and T2* values for macaque cortex, suitable MR imaging sequences, a training schedule, stimulus delivery apparatus and restraining hardware for monkey fMRI using a conventional 19 cm knee coil. Much of our understanding of the functional organization of the primate brain comes from physiological studies in monkeys. Direct comparison between species using fMRI such as those described here will help us to relate the wealth of existing knowledge on the functional organization of the non-human primate brain to human fMRI.

Sport psychology service delivery: staying ethical while keeping loose

Although the parent discipline of sport psychology is psychology, the delivery of sport psychology services has its main roots in physical education and sports science (motor learning and control, skill acquisition). Thus, sport psychologists may look more like coaches than they look like clinicians or counselors. In this article, the authors trace the evolution of sport psychology services and contrast the temporal, spatial, and delivery issues of applied sport psychology with more mainstream counseling and clinical psychology. The looser boundaries of sport psychologist practice have both benefits and dangers, and the authors offer some examples to professional psychologists who are thinking of expanding their delivery of service to athletes and coaches.

Heart rate-perceived exertion relationship during training and taper

BACKGROUND

Examine the heart rate-perceived exertion (HR-RPE) relationship under conditions of high-intensity training and taper.

METHODS

Experimental design and participants: prospective with collegiate cyclists (n=11) completed six weeks of high-intensity interval training, followed by a one-week taper.

INTERVENTIONS

participants completed a high-intensity training regimen along with graded exercise tests (GXT) throughout the training and the taper.

MEASURES

heart rates (HR) and ratings of perceived exertion (RPE) were recorded following each stage of the GXTs. Scores on GXTs were also recorded.

RESULTS

. The HR-RPE relationship during GXTs changed over the course of the training with greater RPEs for a given HR at the end of the training compared to the beginning. The most powerful predictors of the performance response to the taper were training induced changes in the HR-RPE relationship and decreases in HR for a given power output. Those individuals who reported higher RPEs for lower HRs were more likely to have better performance responses to taper (r=0.72) as were those who had larger changes in the HR-power output relationship (r=0.76).

CONCLUSIONS

These results indicate that changes in the HR-RPE relationship during high-intensity training may be used to monitor the magnitude of overreaching that is necessary for a positive response to a taper. For coaches and athletes, the HR-RPE ratio may be a practical measure for monitoring an aspect of fatigue associated with high-intensity training.

Physiotherapists' and male professional athletes' views on psychological skills for rehabilitation

In the literature on the psychological aspects of rehabilitation from athletic injury, several studies in North America have focused on athletic trainers' roles as physical and psychological caregivers for injured athletes. Wiese, Weiss, and Yukelson (1991) examined the views of athletic trainers on the psychological characteristics that distinguished athletes who coped well, versus those who coped poorly with rehabilitation, and also sought athletic trainers opinions on the role of psychological skills in injury rehabilitation. This study replicated the Wiese et al. (1991) study with Australian physiotherapists and extended it to include the viewpoints of professional basketball players. The results indicated the importance attached to communication and motivation by both physiotherapists and athletes in the rehabilitation process. Both athletes and physiotherapists did not, however, think psychological skills such as relaxation or imagery techniques to be particularly useful tools in the recovery process.

What exercise and sport scientists don't understand

The power of research design in studies published in the Australian Journal of Science and Medicine in Sport (AJSMS: now the Journal of Science and Medicine in Sport) for the years 1996 and 1997 were analysed for their ability to detect small, medium, and large effects according to Cohen's (1988) conventions. Also examined were the reporting and interpreting of effect sizes and the control for experiment-wise (EW) Type I error rates. From the two years of articles, 29 studies were analysed, and power was computed on 108 different tests of significance. The median power of the studies to detect small, medium, and large effects were .14, .65 and .97, respectively. These results suggest that exercise and sport science research, at least as represented in AJSMS, is probably underpowered and may be limited in detecting small effects, has a better, but still underpowered, chance of detecting medium effects, and has adequate power principally for detecting large effects. The reporting of effect sizes was rare, and adequate interpretation of them was even rarer. The mean EW Type I error rate for all studies was .49. The analyses conducted suggest that much research in exercise science may have substantial Type I and Type II errors. An appeal is made for exercise scientists to conduct power analyses, control for EW error, exercise caution in the interpretation of nonsignificant results, and examine, report, and interpret effect sizes rather than solely rely on p values to determine whether significant changes occurred or significant relationships exist.

Athletic injury, psychosocial factors and perceptual changes during stress

In this study, we measured changes in state anxiety, visual perception and reaction time during stress among 196 collegiate athletes participating in 10 sports. The athletes also completed measures of life events and social support at the beginning of their seasons. Measures of life events stress, social support, perceptual changes and changes in reaction time during stress were used as predictors of the number of injuries. For the entire sample, the only significant predictor of injury was negative life events stress (R = 0.45, P < 0.001). Following the suggestions of Smith et al., simple correlations were performed for those with least social support (bottom 33%, n = 65). Among this group, those individuals with more negative life events and greater peripheral narrowing during stress incurred more injuries than those with the opposite profile. Our findings are in line with the model of Andersen and Williams, in that those individuals who were low in a variable that buffers stress responsivity (i.e. social support), their negative life events and peripheral narrowing under stress (large and medium effect sizes, respectively) were substantially related to their number of injuries.

Specific behavioral effects related to age and cerebral ischemia in rats

Rats at 4, 14, and 20 months of age were subjected to permanent occlusion of the left middle cerebral artery (MCAO) and the effects of age and ischemia assessed in tests for spatial learning (Morris' water maze), social behavior, olfactory learning, exploratory behavior, and motor function. Furthermore, the extent of ischemic damage to the brain of rats of 5 and 19 months of age was studied. An age-related decline in water-maze performance was observed, and aged rats were less agile, less explorative, and less frequently engaged in social interactions than young rats. After ischemia, mild memory impairment was observed in old rats, while changes in some exploratory behaviors were observed in young rats. Neuropathological analyses revealed a variable and limited degree of infarction in the piriform cortex and the insular cortex with no difference between age groups. In conclusion, the present study confirmed and extended current data on behavioral differences between young and old rats. MCAO had limited influence on the tested behaviors.

Postischemic hyperactivity in the Mongolian gerbil correlates with loss of hippocampal neurons

Gerbils show a postischemic increase in locomotor activity that correlates to the extent of neuron loss in the hippocampal CA1 subfield. It has been suggested that this hyperactivity is predictive of neuron loss in the CA1. In this study the correlation between postischemic hyperactivity and neuron loss in several hippocampal subfields was investigated, and the theory that the hyperactivity is due to a reduced ability for spatial navigation was evaluated. Significant correlations were found between hyperactivity and neuron loss in several hippocampal subfields; the correlation was stronger for the CA3 than for the CA1 subfield, suggesting that postischemic hyperactivity can be used as a predictor of neuron loss in the CA3 rather than in the CA1. From observations of the pattern of hyperactivity within the test arenas and during the test period, this study challenges the spatial mapping theory of postischemic hyperactivity.

[Stab and cut lesions among general practitioners in the county of Funen]

In a questionnaire sent out to general practitioners (GP) in the County of Funen they reported a yearly incidence of lesions penetrating the skin of 1.2 per practitioner. Approximately half of these lesions were potentially infectious. Sixty percent of the lesions were due to accidents involving needles. Only 52% of the GPs with the risk of a potentially infectious lesion tried to prevent infection. We estimate that the risk of becoming infected with HIV or Hepatitis-B infection is very low. It is necessary to get GPs to change procedures in an attempt to minimize the risk.

Impairment of working memory in the T-maze after transient global cerebral ischemia in the Mongolian gerbil

Using a T-maze, the influence of transient global cerebral ischemia on working memory in gerbils was investigated. Furthermore, it was examined whether a correlation exists between impairment in choice accuracy in the T-maze and neuron loss in the hippocampus. In two experiments, male Mongolian gerbils were tested in a previously learned delayed alternation T-maze task 1 week after a 4 min occlusion of the common carotid arteries. In both experiments memory was significantly impaired and in the second experiment, where the design allowed a separation between working and reference memory deficits, a selective impairment in working memory was seen. The results suggest that ischemia-induced disruption of delayed alternation in the T-maze in gerbils is a model which is relevant to the clinical manifestations of vascular dementia.

Postischemic hyperactivity in the Mongolian gerbil correlates with loss of hippocampal neurons

Gerbils show a postischemic increase in locomotor activity that correlates to the extent of neuron loss in the hippocampal CA1 subfield. It has been suggested that this hyperactivity is predictive of neuron loss in the CA1. In this study the correlation between postischemic hyperactivity and neuron loss in several hippocampal subfields was investigated, and the theory that the hyperactivity is due to a reduced ability for spatial navigation was evaluated. Significant correlations were found between hyperactivity and neuron loss in several hippocampal subfields; the correlation was stronger for the CA3 than for the CA1 subfield, suggesting that postischemic hyperactivity can be used as a predictor of neuron loss in the CA3 rather than in the CA1. From observations of the pattern of hyperactivity within the test arenas and during the test period, this study challenges the spatial mapping theory of postischemic hyperactivity.

Student and supervisor perceptions of the quality of supervision in athletic training education

OBJECTIVE

To assess the perceptions of the quality of athletic training supervision via the internship route to certification and the NATA-approved/CAAHEP programs.

DESIGN AND SETTING

A questionnaire was mailed to head athletic trainers or NATA/CAAHEP program directors and athletic training students in 40 programs nationwide (stratified random sample).

SUBJECTS

Head athletic trainers (20), NATA-approved or CAAHEP-accredited program directors (20), and athletic training students in those educational programs (149).

MEASUREMENTS

The Athletic Training Supervisory Skills Inventory (ATSSI) was adapted from the Supervisory Evaluation Form (SEF) and athletic training literature. The ATSSI was reviewed by 30 certified athletic trainers, and their feedback was incorporated into the final version of the questionnaire. The ATSSI contains 46 questions that cover six major domains of athletic training supervisor behavior.

RESULTS

Overall, there were no differences in how internship route supervisors and NATA/CAAHEP program directors rated their own supervisory skills. Also, there were few differences in how students in those two types of athletic training education programs rated their supervisors.

CONCLUSIONS

This exploratory study's limitations included a one-time assessment approach and a small sample of supervisors. Future studies in supervision should take a longitudinal approach and include a larger sample size.

Perceived uncertainty of outcome as a contributing factor in competitive state anxiety

The Martens, Vealey, and Burton (1990) model of competitive anxiety contains perceived uncertainty, perceived importance, and competitive trait anxiety (A-trait) as key determinants affecting a person's perception of threat and competitive state anxiety (A-state). This experiment tested perceived uncertainty of outcome and A-trait influences on A-state. Club level golfers (N = 72) were assigned to either a low uncertainty condition (LU) or a high uncertainty (HU) condition. In this experiment participants were matched and competed for 12 golf balls in a modified chipping competition. Participants also completed the Competitive State Anxiety Inventory -2 and the Match Orientation Questionnaire (a measure of perceived uncertainty) prior to, and during breaks in the competition. Players alternated in taking four rounds of eight shots from a zone marked approximately 30 metres from the hole. A series of tests did not support the manipulation of uncertainty. This was probably due to likely losers and likely winners not experiencing similar levels of A-state, as Martens et al. assume. Recoding the uncertainty data to reflect levels of confidence, and entering confidence and A-trait into multiple regression equations resulted in these two variables accounting for between 15% and 23% of the A-state variance at different stages of the competition. Recommendations for future research, and possible revisions of the model in light of the present findings are discussed.

Aseptic loosening of BonelocR cemented hip prostheses

We present a systematic clinical and radiographic study of 147 patients who had total hip replacements from February 1992 to May 1993. BonelocR cement was used in 108, and PalacosR cement with gentamicin in 39 patients who had an increased risk of infection. At follow-up after 24 to 39 months, 26 cases with BonelocR cement had failed; there were no clinical failures in the PalacosR group.

Transient cerebral ischemia inhibits juvenile recognition in the Mongolian gerbil

This study introduces a social recognition test for Mongolian gerbils and describes the effect of transient global cerebral ischemia in this model. Adult male gerbils were exposed to an unfamiliar juvenile stimulus animal in two successive trials. The difference between the first and second exposures in duration of social investigation of the stimulus animal was used as a measure of social recognition. Recognition of the stimulus animal was seen after interexposure intervals (IEI) of 5 and 30 min, but not after 120 min. This is in concordance with data obtained in rats in a similar model. The capacity for social recognition was subsequently investigated in gerbils 1 week after 0 (sham), 4, or 8 min of bilateral occlusion of the common carotid arteries. An IEI of 30 min was used, as this IEI was within the time limit for recognition of the stimulus animal. Social recognition was impaired in both occlusion groups. The results suggest that the juvenile recognition test is a suitable model for testing amnesia in gerbils and that social olfactory memory is impaired by global cerebral ischemia.

Psychosocial influences on central and peripheral vision and reaction time during demanding tasks

We examined perceptual deficits hypothesized in a model of stress and injury relationships. An ophthalmologic perimeter was used to measure peripheral and central vision during baseline and demanding task situations for 201 intercollegiate athletes from 10 sports. We conducted analyses of covariance with the stress measures as dependent variables and their appropriate baseline measures as covariates. Performance under demanding tasks deteriorated significantly on all the perceptual variables. Individuals with high negative life events scores experienced greater peripheral narrowing and slower central vision reaction time during stress than did those with life events scores that were low. Men with low social support had more failures to detect cues, and men with high negative life events, low social support, and low coping skills had the lowest perceptual sensitivity. Women with high negative life events and low coping skills had more failures to detect cues. We discuss the findings in terms of how stress responsivity may influence injury risk through changes in perception and attention.

Discrimination between artefacts and contractions in pressure signals from the gastrointestinal tract by pattern recognition method

A pattern recognition algorithm has been developed to discriminate between artefacts and contractions in interdigestive motility recorded by a pressure catheter with four channels from the human duodenum. A learning and a test set, both containing natural and induced artefacts, such as respiration and body movement, are obtained from five volunteers. The event classes were phase I, II and III contractions of the interdigestive motility complex and artefacts from respiration, cough, calibration signals and movements. Length, area, amplitude, inter-event interval, up- and downstroke, and correlation to other pressure channels and to respiration, are applied to classify the events. The sensitivity of the computer scoring increases with the number of applied features. When all the features are applied, the sensitivity of the Bayes' classifier against the visually scored contractions and artefacts is 0.96 with a specificity of 0.69.

Rabbit sphincter of Oddi and duodenal pressure and slow-wave activity. Effects of cholecystokinin

BACKGROUND

The presence of sphincter of Oddi (SO) slow waves has been noted in earlier studies on the effect of cholecystokinin (CCK) on the SO, but a more thorough description of changes in SO slow-wave and pressure activity induced by CCK is needed.

METHODS

The SO and duodenum in anaesthetized rabbits were prepared with perfused catheters and bipolar electrodes. Increasing, successive doses of CCK (1/32 to 1/1 Ivy Dog Units (IDU)/kg) were administered intravenously every 15th min. The digitized recordings were scored on a computer in control and stimulatory CCK sequences.

RESULTS

CCK had a significantly stimulatory effect on SO and duodenum when estimated as area below pressure peaks (p < 0.001), but quantitatively, this effect did not differ in the two organs (p = 0.59). CCK significantly decreased SO slow-wave frequency (p < 0.05), whereas a similar trend in duodenal slow-wave frequency failed to reach statistical significance. Most pressure peaks recorded from the SO were associated with only one slow wave ('simple peak'), but the incidence of broad, irregular peaks belonging to more than one slow wave ('complex peaks') was significantly higher in CCK sequences (p < 0.02). Spectral analysis of SO pressure and slow-wave activity confirmed the dominating one-to-one relation between SO slow-wave and pressure peaks up to 1/4 IDU/kg, but also showed the disturbance caused by the increasing number of complex peaks generated by doses of at least 1/2 IDU/kg.

CONCLUSIONS

CCK increases SO and duodenal activity equally. Up to a CCK dose of 1/4 IDU/kg the SO slow-wave regulatory mechanism is undisturbed, but higher doses lead to a fall in slow-wave frequency and qualitative changes in the relation between SO pressure and slow-wave activity.

Positive states of mind and athletic injury risk

Horowitz, Adler, and Kegeles recently developed the Positive States of Mind (PSOM) scale to assess the ability to achieve desirable states of mind. According to a stress and injury model, a theoretical foundation exists for the PSOM being used to predict vulnerability to athletic injuries. In the first study, 277 collegiate athletes from 10 sports completed the PSOM. The scale showed good internal consistency; Cronbach's alpha was .77 for the six items. Principle components factor analysis revealed two distinct factors. No sex or ethnic differences occurred for the total PSOM scale or the two factors. In the second study, injury data were gathered throughout the season on 82 athletes who completed the PSOM. Pearson-product correlations revealed the factor, Focused on Task, significantly correlated with injury. Athletes able to attain higher positive states of mind were less at risk for injury. The studies indicate the acceptability of using the PSOM with an athletic population and its usefulness as a potential predictor of injury risk. Future research using the PSOM scale in more general injury and accident investigations is suggested.

Double dislocation of the interphalangeal joints in the finger. Case report and review of publications

A 66-year-old woman presented with a painful swollen finger and was shown radiographically to have dorsal dislocation of both interphalangeal joints, which responded to immobilisation and physiotherapy. Unlike single dislocations of finger joints double dislocations are rare, only 52 cases have been reported between 1874 and 1992 to our knowledge.

Computer-aided analysis of gastrointestinal pressure recordings. Comparison with manual scoring

The aim of the present study was to compare computer-based and visual/manual scoring of pressure recordings from the gastric antrum and duodenum. The computer system was based on three separate principles of recognition: moving average, tracking base line, and threshold filters. Computer scoring resulted in the detection of more contractions than visual/manual scoring, owing to inclusion of artefacts of duration and amplitude above the selected thresholds. Owing to its unreliability, visual/manual scoring led to inclusion of some contractions of below-borderline amplitude or duration. The median difference in the frequency of contractions was, however, 0 min-1. There was close agreement on amplitudes of contractions. As the differences between visual/manual analysis and computer-aided scoring by the present system are of an unimportant magnitude and as computer-based scoring is consistent, we conclude that computer-aided analysis is preferable to visual/manual analysis.

Comparison of structure and activities of peroxidases from Coprinus cinereus, Coprinus macrorhizus and Arthromyces ramosus

Initial structural and kinetic data suggested that peroxidases from Coprinus cinereus, Coprinus macrorhizus and Arthromyces ramosus were similar. Therefore they were characterized more fully. The three peroxidases were purified to RZ 2.5 and showed immunochemical identity as well as an identical M(r) of 38,000, pI about 3.5 and similar amino acid compositions. The N-termini were blocked for amino acid sequencing. The peroxidases had similar retention volumes by anion-exchange and gel-filtration chromatography. All peroxidases showed multiple peaks by Concanavalin A-Sepharose chromatography. The Concanavalin A-Sepharose profiles were different and depended furthermore on a fermentation batch. Tryptic peptide maps were very similar except for one peptide. This peptide contained an N-linked glycan composed of varying ratios of glucosamine and mannose for the three peroxidases. Rate constants and their pH dependence were the same for the three peroxidases using guaiacol or iodide as reducing substrates. We conclude that peroxidases from Coprinus cinereus, Coprinus macrorhizus and Arthromyces ramosus are most likely identical in their amino acid sequences, but deviate in glycosylation which, apparently, has no influence on the reaction rates of the enzyme. We suggest, that the Coprinus fungi express one peroxidase only in contrast to the lignin-degrading white-rot Basidiomycetes, which produce multiple peroxidase isozymes.

Radial analysis of duodenal motility recordings in humans

To analyze radial variations in pressure recordings from the human duodenum, we used a catheter with six radially placed side holes with identical dynamic characteristics. Twenty-one hours of fasting pressure recordings were obtained in six volunteers. Computer-based cross-correlation analysis, event detection and counting, amplitude analysis, and concordance analysis were used for comparing the signals of the individual channels. Both the cross-correlation analysis and the counting of events showed radial asymmetry of contractile activity. This asymmetry was not related to any individual channel. The maximum difference between the individual channels was constantly between diametrically opposite spaced channels. The asymmetry was most pronounced during phase-I-like and phase-II-like activity of the migrating motility complex, whereas a much higher degree of cross-correlation and concordance was shown during phase-III-like activity. The results indicate that a greater in-depth analysis of pressure recordings from the small intestine--such as identification of individual events and differentiation between contractions and artefacts--requires that the recordings as a minimum comprise two diametrically placed side holes at each measurement level.

Versatile software system for analysis of gastrointestinal pressure recordings

A software package, MotAn, has been developed for off-line analysis of gastrointestinal pressure recordings. The program has been implemented in the Modula-2 language for use on IBM personal computers. The program includes capabilities for manual or automatic detection of contractions, calculation of frequency and intercontractile intervals, area of contractions, motility index, concordance and cross-correlation analysis for detection of artifact and for propagation analysis. The program has been applied on pressure recordings from the stomach and duodenum as well as on the rectum and the urinary bladder. Besides the basic part of the program, it is possible for the experienced programmer to add new blocks of object code for development of special analysis procedures.

Effects of life-event stress on anxiety and peripheral narrowing

This study examined one of the mechanisms proposed to be behind the relationship between life stress and injury. Past researchers have identified a correlation between high life stress and athletic injury for contact and noncontact sports and for male and female athletes, but they did not investigate why athletes who experienced stress from life events were more prone to injury than those whose lives were low in stressful events. The authors tested the hypothesis that recreational athletes with high life-event stress would, when placed in a stressful, dual-task laboratory situation, experience greater narrowing of peripheral vision and state anxiety than recreational athletes with low life-event stress. ANOVA and regression results offered support for peripheral vision deficits as a potential mechanism in the life stress-injury relationship and very minimal support the effect of elevated state anxiety. The great variability in peripheral vision changes for the groups with high life stress suggests that, for certain subjects, some unmeasured variable may be buffering the adverse impact of high life-event stress. The authors recommend that future researchers examine potential moderating variables, such as coping resources, and assess the relative contributions of psychosocial variables, stress history variables, and mediating mechanisms in predicting actual injuries.

Consistency in manual scoring analysis of gastrointestinal pressure recordings

The aim of the present study was to evaluate the consistency in visual scoring and whether this could be the basis for computer analysis using pattern recognition techniques. We studied the consistency of visual scoring of pressure tracings from the upper gastrointestinal tract with regard to pressure wave identification. The aim was to make such an identification the golden standard for computerized analysis of pressure waves. Pressure recordings containing different phases of contraction activity were evaluated by five trained observers. The inter- and intra-observer agreement was highest in periods with high contraction activity (phase III), both of which were better than 90%. In periods with low contraction activity (phases I and II) this agreement was as low as 49%. The results indicate that forming a learning set for pattern recognition should only be based on visual scoring during phase-III activity.