High-dimensional analyses reveal a distinct role of T-cell subsets in the immune microenvironment of gastric cancer

Objectives

To facilitate disease prognosis and improve precise immunotherapy of gastric cancer (GC) patients, a comprehensive study integrating immune cellular and molecular analyses on tumor tissues and peripheral blood was performed.

Methods

The association of GC patients' outcomes and the immune context of their tumors was explored using multiplex immunohistochemistry (mIHC) and transcriptome profiling. Potential immune dysfunction mechanism/s in the tumors on the systemic level was further examined using mass cytometry (CyTOF) in complementary peripheral blood from selected patients. GC cohorts with mIHC and gene expression profiling data were also used as validation cohorts.

Results

Increased CD4⁺FOXP3⁺ T-cell density in the GC tumor correlated with prolonged survival. Interestingly, CD4⁺FOXP3⁺ T cells had a close interaction with CD8⁺ T cells rather than tumor cells. High densities of CD4⁺FOXP3⁺ T cells and CD8⁺ T cells (High-High) independently predicted prolonged patient survival. Furthermore, the interferon-gamma (IFN-γ) gene signature and PDL1 expression were up-regulated in this group. Importantly, a subgroup of genomically stable (GS) tumors and tumors with chromosomal instability (CIN) within this High-High group also had excellent survival. The High-High GS/CIN tumors were coupled with increased frequencies of Tbet⁺CD4⁺ T cells and central memory CD4⁺ T cells in the peripheral blood.

Conclusion

These novel findings identify the combination of CD8⁺ T cells and FOXP3⁺CD4⁺ T cells as a significant prognostic marker for GC patients, which also could potentially be targeted and applied in the combination therapy with immune checkpoint blockades in precision medicine.

The influence of evolutionary history and body size on partitioning of habitat resources by mammalian herbivores in south-eastern Australia

Habitat use is the most common dimension along which sympatric species partition resources to reduce competition. We conducted faecal pellet counts at Wilsons Promontory National Park, Victoria, to examine habitat use by an assemblage of mammalian herbivores with disparate evolutionary histories and varying body size: introduced European rabbit (Oryctolagus cuniculus) and hog deer (Axis porcinus), and native eastern grey kangaroo (Macropus giganteus), swamp wallaby (Wallabia bicolor) and common wombat (Vombatus ursinus). Overlap in habitat use was low between four pairs of species, suggesting spatial partitioning of resources to reduce the potential for interspecific competition. More generally, however, overlap in habitat use was high, particularly between native and introduced grazers. These results indicate the potential for competition if resources were limiting and suggest that assemblages of species with independent evolutionary histories have inherently less resource partitioning to facilitate coexistence than assemblages of species with common evolutionary histories. Despite evidence of high overlap in habitat use between native and introduced species at a broad scale, and variation in the competitive ability of species, coexistence was likely facilitated by niche complementarity, including temporal and fine-scale partitioning of spatial resources. There was no relationship between body size and the diversity of habitats used. In contemporary assemblages of native and introduced species, evolutionary history is likely to have a strong influence on resource partitioning.

Ultrasonography in the intensive care setting can be used to detect changes in the quality and quantity of muscle and is related to muscle strength and function

PURPOSE

This study aimed to (1) document patterns of quadriceps muscle wasting in the first 10 days of admission and (2) determine the relationship between muscle ultrasonography and volitional measures.

MATERIALS AND METHODS

Twenty-two adults ventilated for more than 48 hours were included. Sequential quadriceps ultrasound images were obtained over the first 10 days and at awakening and intensive care unit (ICU) discharge. Muscle strength and function were assessed at awakening and ICU discharge.

RESULTS

A total of 416 images were analyzed. There was a 30% reduction in vastus intermedius (VI) thickness, rectus femoris (RF) thickness, and cross-sectional area within 10 days of admission. Muscle echogenicity scores increased for both RF and VI muscles by +12.7% and +25.5%, respectively (suggesting deterioration in muscle quality). There was a strong association between function and VI thickness (r = 0.82) and echogenicity (r = -0.77). There was a moderate association between function and RF cross-sectional area (r = 0.71).

CONCLUSIONS

Muscle wasting occurs rapidly in the ICU setting. Ultrasonography is a useful surrogate measure for identifying future impairment. Vastus intermedius may be an important muscle to monitor in the future because it demonstrated the greatest change in muscle quality and had the strongest relationship to volitional measures.

Minimal important difference of the 6-minute walk distance in lung cancer

The 6-minute walk distance (6MWD) is one of the most commonly used measures of functional capacity in lung cancer, however, the minimal important difference (MID) has not been established. The aims of this exploratory study are, in lung cancer, to estimate (1) the MID of the 6MWD and (2) relationship between 6MWD, demographic and disease-related factors. Fifty-six participants with stage I–IV lung cancer completed the 6MWD prior to treatment and 10 weeks later. No exercise intervention occurred. Additional measures included European Organization for Research and Treatment of Cancer questionnaire (EORTC-QLQ-C30) and questionnaires assessing function, physical activity and symptoms. MID was calculated using anchor- and distribution-based methods. The mean 6MWD decline in participants classed as deteriorated was 60 m compared with 16 m in participants classed as not-deteriorated ( p = 0.01). The receiver operating curve indicated a cut-off value for clinically relevant change to be 42 m (95% confidence interval (CI) 6–75) (area under curve = 0.66, 95% CI 0.51–0.81) or a 9.5% change. Distribution-based methods indicated an MID between 22 m (95% CI 18–26) and 32 m (95% CI 20–42). Higher 6MWD correlated with better function ( r = −0.42, p = 0.001), physical activity ( r = 0.56, p < 0.005) and dyspnoea ( r = −0.44, p = 0.001). The MID for deterioration of the 6MWD in lung cancer is estimated to be between 22 m and 42 m or a change of 9.5%.

Water Equivalent Thickness Analysis of Immobilization Devices for Clinical Implementation in Proton Therapy

Immobilization devices can impact not only the inter- and intra-fraction motion of the patient, but also the range uncertainty of the treatment beam in proton therapy. In order to limit additional range uncertainty, the water equivalent thickness (WET) of the immobilization device needs to be well known and accurately reflected in the calculations by the treatment planning system (TPS). The method presented here focusses on the use of a nozzle-mounted variable range shifter and precision-machined polystyrene blocks of known WET to evaluate commercial immobilization devices prior to clinical implementation. CT studies were also completed to evaluate the internal uniformity of the immobilization devices under study. Multiple inserts of the kVue platform (Qfix Systems, Avondale, PA) were evaluated as part of this study. The results indicate that the inserts are largely interchangeable across a given design type and that the measured WET values agree with those generated by the TPS with a maximum difference less than 1 mm. The WET of the devices, as determined by the TPS, was not impacted by CT beam hardening normally experienced during clinical use. The reproducibility of the WET method was also determined to be better than ±0.02 mm. In conclusion, the testing of immobilization prior to implementation in proton therapy is essential in order to ascertain their impact on the proton treatment and the methodology described here can also be applied to other immobilization systems.

A postoperative shoulder exercise program improves function and decreases pain following open thoracotomy: a randomised trial

QUESTION

Does a postoperative physiotherapy exercise program incorporating shoulder exercises improve shoulder function, pain, range of motion, muscle strength, and health-related quality of life in patients undergoing elective pulmonary resection via open thoracotomy?

DESIGN

Randomised trial with concealed allocation, assessor blinding, and intention-to-treat analysis.

PARTICIPANTS

76 patients who underwent pulmonary resection via open thoracotomy.

INTERVENTION

All participants received standard medical and nursing care involving a clinical pathway. The experimental group also received physiotherapy interventions that included daily supervised, progressive exercises until discharge and a postoperative exercise booklet on discharge.

OUTCOME MEASURES

Preoperatively and up to 3 months postoperatively pain was measured with a numerical rating scale, shoulder function with the Shoulder Pain and Disability Index, and quality of life with the Short Form-36. Shoulder range of motion and muscle strength were measured in a subgroup.

RESULTS

The experimental group had 1.3 units (95% CI 0.3 to 2.2) less shoulder pain (scored /10) and 2.2 units (95% CI 0.2 to 4.3) less total pain (scored /30) at discharge, and 7.6% (95% CI 1.7 to 13.6) better function at 3 months. The Short Form-36 physical component score was 4.8 points (95% CI -0.3 to 10.0) better for the experimental group than the control group at 3 months. Differences between groups in all range of motion and strength measures were small and statistically non-significant.

CONCLUSION

A physiotherapist-directed postoperative exercise program resulted in significant benefits in pain and shoulder function over usual care for patients following open thoracotomy.

TRIAL REGISTRATION

ANZCTRN 12605000201673.

Leukemia inhibitory factor signaling modulates both central nervous system demyelination and myelin repair

Leukemia inhibitory factor (LIF) receptor signaling limits the severity of inflammatory demyelination in experimental autoimmune encephalomyelitis, a T-cell dependent animal model of multiple sclerosis (MS) [Butzkueven et al. (2002) Nat Med 8:613-619]. To identify whether LIF exerts direct effects within the central nervous system to limit demyelination, we have studied the influence of LIF upon the phenotype of mice challenged with cuprizone, a copper chelator, which produces a toxic oligodendrocytopathy. We find that exogenously administered LIF limits cuprizone-induced demyelination. Knockout mice deficient in LIF exhibit both potentiated demyelination and oligodendrocyte loss after cuprizone challenge, an effect that is ameliorated by exogenous LIF, arguing for a direct beneficial effect of endogenous LIF receptor signaling. Numbers of oligodendrocyte progenitor cells in cuprizone-challenged mice are not influenced by either exogenous LIF or LIF deficiency, arguing for effects directed to the differentiated oligodendrocyte. Studies on the influence of LIF upon remyelination after cuprizone challenge fail to reveal any significant effect of exogenous LIF. The LIF-knockout mice do, however, display impaired remyelination, although oligodendrocyte replenishment, previously identified to occur from the progenitor pool, is not significantly compromised. Thus endogenous LIF receptor signaling is not only protective of oligodendrocytes but can also enhance remyelination, and exogenous LIF has therapeutic potential in limiting the consequences of oligodendrocyte damage.

Accounting for dependence in similarity data from DNA fingerprinting

Differentiating strains of a pathogen is often central to investigating its epidemiological aspects. The genetic similarity of a group of strains can be assessed by calculating a matrix of dissimilarities from their DNA fingerprinting profiles. The mean dissimilarity for each strain across other strains within the group is then used as an observation in a statistical analysis. These observations are not independent of each other, and so standard analysis techniques such as the t-test are inappropriate, because they underestimate the variance of the group means, and hence overstate the statistical significance of any differences. By examining the correlation between elements of the dissimilarity matrix, it is shown that the variance is underestimated by a factor of between about 2 and 4. Permutation tests are proposed as a way of addressing the problem of dependence, and are applied to a study of fluconazole resistance in Candida albicans.

A simple method for inference on an overall effect in meta-analysis

The random effects approach in meta-analysis due to DerSimonian and Laird is well established and used pervasively. It has been established by Brockwell and Gordon that this method, when used for confidence intervals, leads to coverage probabilities lower than the nominal value. A number of alternatives have been proposed, but these either have the defect of iterative and complicated calculation, or deficient coverage. In this paper we propose a new approach, which is simple to use, and has coverage probabilities better than the alternatives, based on extensive simulation. We call this approach the 'quantile approximation' method.

An outbreak of Legionnaires' disease at the Melbourne Aquarium, April 2000: investigation and case-control studies

OBJECTIVE

To investigate the source and risk factors associated with Australia's largest outbreak of Legionnaires' disease.

DESIGN AND SETTING

Epidemiological and environmental investigation of cases of Legionnaires' disease associated with visits to the Melbourne Aquarium; two case-control studies to confirm the outbreak source and to investigate risk factors for infection, respectively.

PARTICIPANTS

Patients with confirmed Legionnaires' disease who visited the Melbourne Aquarium between 11 and 27 April 2000 were compared (i) with control participants from the community, and (ii) with control participants selected from other visitors to the Aquarium during this period.

MAIN OUTCOME MEASURES

Risk factors for acquiring Legionnaires' disease.

RESULTS

There were 125 confirmed cases of Legionnaires' disease caused by Legionella pneumophila serogroup 1 associated with the Aquarium; 76% of patients were hospitalised, and four (3.2%) died. The Aquarium cooling towers were contaminated with this organism. Visiting the Aquarium was significantly associated with disease (odds ratio [OR], 207; 95% CI, 73-630). The case-control study indicated that current smoking was a dose-dependent risk (multivariable OR for currently smoking > 70 cigarettes/week, 13.5; 95% CI, 5-36), but chronic illness and duration of exposure at the site were not significant risks.

CONCLUSIONS

This study showed an association between poorly disinfected cooling towers at the Aquarium and Legionnaires' disease in visitors, and confirmed current smoking as a critical risk factor. The rapid response, publicity, and widespread urinary antigen testing may have resulted in detection of milder cases and contributed to the relatively low apparent morbidity and mortality rates. The urinary antigen test allows rapid identification of cases and may be changing the severity of illness recognised as Legionnaires' disease and altering who is considered at risk.

A comparison of statistical methods for meta-analysis

Meta-analysis may be used to estimate an overall effect across a number of similar studies. A number of statistical techniques are currently used to combine individual study results. The simplest of these is based on a fixed effects model, which assumes the true effect is the same for all studies. A random effects model, however, allows the true effect to vary across studies, with the mean true effect the parameter of interest. We consider three methods currently used for estimation within the framework of a random effects model, and illustrate them by applying each method to a collection of six studies on the effect of aspirin after myocardial infarction. These methods are compared using estimated coverage probabilities of confidence intervals for the overall effect. The techniques considered all generally have coverages below the nominal level, and in particular it is shown that the commonly used DerSimonian and Laird method does not adequately reflect the error associated with parameter estimation, especially when the number of studies is small.

Effect of casemix funding on outcomes in patients admitted to hospital with suspected unstable angina

OBJECTIVES

To determine the effect of the introduction of casemix funding on resource utilisation and clinical outcomes in patients admitted to hospital with suspected unstable angina.

DESIGN

A prospective cohort study with a 6-month follow-up.

SETTING

A suburban community hospital in Melbourne, Victoria.

PATIENTS

336 consecutive patients admitted to the coronary care unit with suspected unstable angina before (156) and after (180) the introduction of casemix funding.

INTERVENTION

Introduction of casemix funding in July 1993.

MAIN OUTCOME MEASURES

Indices of resource utilisation: length of stay in hospital, length of stay in the coronary care unit, and total cost of investigations (pathology and radiology). Rates of serious cardiac events during hospital stay and after discharge. Readmissions within 28 days and 6 months of discharge.

RESULTS

After the introduction of casemix funding there was a 1% increase in duration of hospital stay and a 5% increase in time spent in the coronary care unit, but neither of these increases was statistically significant. However, there was a significant reduction in total cost of investigations (39% decrease; 95% confidence interval, 14%-70%; P < 0.001). The rate of serious cardiac events after discharge did not increase, and neither did readmission rates, either within 28 days or over the 6 months' follow-up.

CONCLUSION

Casemix funding had no effect on short term clinical outcomes but resulted in significantly reduced investigation costs.

Cancer incidence and mortality and proximity to TV towers

OBJECTIVE

To determine whether there is an increased cancer incidence and mortality in populations exposed to radiofrequency radiations from TV towers.

DESIGN

An ecological study comparing cancer incidence and mortality, 1972-1990, in nine municipalities, three of which surround the TV towers and six of which are further away from the towers. (TV radiofrequency radiation decreases with the square of the distance from the source.) Cancer incidence and mortality data were obtained from the then Commonwealth Department of Human Services and Health. Data on frequency, power, and period of broadcasting for the three TV towers were obtained from the Commonwealth Department of Communications and the Arts. The calculated power density of the radiofrequency radiation in the exposed area ranged from 8.0 microW/cm2 near the towers to 0.2 microW/cm2 at a radius of 4km and 0.02 microW/cm2 at 12 km.

SETTING

Northern Sydney, where three TV towers have been broadcasting since 1956.

OUTCOME MEASURES

Rate ratios for leukaemia and brain tumour incidence and mortality, comparing the inner with the outer areas.

RESULTS

For all ages, the rate ratio for total leukaemia incidence was 1.24 (95% confidence interval [CI], 1.09-1.40). Among children, the rate ratio for leukaemia incidence was 1.58 (95% CI, 1.07-2.34) and for mortality it was 2.32 (95% CI, 1.35-4.01). The rate ratio for childhood lymphatic leukaemia (the most common type) was 1.55 (95% CI, 1.00-2.41) for incidence and 2.74 (95% CI, 1.42-5.27) for mortality. Brain cancer incidence and mortality were not increased.

CONCLUSION

We found an association between increased childhood leukaemia incidence and mortality and proximity to TV towers.

Duration dependence in migration behaviour: cumulative inertia versus stochastic change

"In this paper a new theoretical framework and supporting empirical evidence on the relationship between movement probabilities and length of stay are presented. Individuals' evaluations of the relative value of alternative locations are assumed to evolve stochastically, with a possible tendency either to cumulative inertia or to cumulative stress. In general this yields a nonmonotonic duration function, with probabilities of movement starting at zero, rising and then falling--a pattern consistent with either cumulative tendency, or neither. A version of the model fitted to data on household movement intentions, from the U.K. General Household Survey, confirms the hypothesised form of this function and indicates a dominance of cumulative stress over cumulative inertia."

Suicide and related deaths in Victorian doctors

A cohort of University of Melbourne medical graduates (1950-1959 graduates inclusive) was followed up until December 31, 1986. Vital status at the end of the study period was ascertained and, for those who had died, cause of death was determined. The cohort consisted of 1453 members (1279 men and 174 women). One hundred and twenty-six of the group had died (115 men and 11 women) and 68 (4.7%; 57 men and 11 women) were lost to follow-up. The major causes of death were cardiovascular disease and malignant neoplasms. The standardised mortality ratios (SMRs) for all-cause mortality were low (59 for the male doctors and 84 for the female doctors) indicating that male doctors experience a "force of mortality" 59% that of the general population and female doctors 84%. For the male doctors, the SMR for suicide was 113 (95% confidence interval [CI], 54-207) (10 of 115 deaths in male doctors) about double the SMR for mortality from all causes. For the female doctors, the SMR for suicide was 501 (95% CI, 103-1500) (3 of 11 deaths in female doctors). For deaths resulting from all accidents the SMR was low for the males (29) and higher for the females (126). The SMR for mental disorders for the male doctors was marginally raised (132). This study reveals some indication of a problem in doctors in regard to deaths by suicide, other violent deaths and mental disorders. A larger study involving a control group of equivalent social class is required to confirm the findings of this study.

The bristol registry of bone dysplasias: the first 10 years

The Bristol Bone Dysplasia Registry was established in 1969. The panel included radiologists, paediatricians, orthopaedic surgeons, pathologists, a paediatric biochemist, an anatomist/anthropologist, a veterinary surgeon, dentists and oral surgeons, and a psychiatrist. The panel met every two months. Cases either entered the Registry directly if they were straightforward or after discussion by the panel if there was doubt about the diagnosis or a point of special interest. A total of 468 cases was collected, including 81 cases with miscellaneous bony disorders and 34 cases where the diagnosis was uncertain. The Registry provided a useful regional diagnostic service and promoted interest in body dysplasias. Some of the research aims have not yet been fully achieved. This paper explains how the Registry is run to help those whom it is hoped will set up similar registries elsewhere.

The Patterson syndrome, leprechaunism, and pseudoleprechaunism

A bizarre syndrome has hitherto masqueraded as leprechaunism, and although it is a quite different disorder it has been used as the prototype of leprechaunism in some birth defects atlases. It is proposed that this condition is designated the Patterson syndrome and details of a second case are reported. The features of this connective tissue and neuroendocrine disorder include bronzed hyperpigmentation, cutis laxa of the hands and feet, bodily disproportion, severe mental retardation, and major bony deformities. Radiographs revealed a unique and gross generalised skeletal dysplasia, unlikely to be confused with any other disorder. This endocrine abnormality comprised hyperadrenocorticism, cushingoid features, and diabetes mellitus in the first case, and premature adrenarche in the second case. The pathogenesis and aetiology of the Patterson syndrome are unknown, although quantitative and qualitative abnormalities of mucopolysaccharide excretion were found in the second case.

Height and skeletal maturity in children with newly-diagnosed juvenile-onset diabetes

Height and skeletal maturity scores (TW 2) were determined in 77 diabetic children at diagnosis and again in 48 of them after 1 to 4 years on insulin treatment. Boys, especially those of prepubertal age, were tall at onset. Girls had normal stature, but showed significant growth retardation after treatment. Skeletal maturity was appreciably advanced in both sexes at diagnosis, and on treatment returned to normal only in boys. Girls maintained their advanced skeletal maturity, resulting in an increased disparity between height and skeletal maturity. The results of this study suggest that a prediabetic metabolic abnormality may enhance skeletal maturity in children with diabetes and continues to operate in girls after treatment, despite a reduced growth rate.

Keratan sulphate excretion in a patient with Kniest dysplasia

The clinical and radiological features of a patient with Kniest dysplasia, a form of metatropic dwarfism, are described. The patient excreted glycosaminoglycans (mucopolysaccharides) in normal amounts during infancy but subsequently showed abnormal keratan sulphate excretion. The significance of these findings and the possibility that Kniest dysplasia represent another mucopolysaccharidosis are discussed.

Cystic fibrosis, atopy, and airways lability

In a survey of cystic fibrosis (CF) in the Avon area, 48 children with CF from 40 families together with 71 of their parents were studied by spirometry, exercise tests, and pinch tests. A control group of 42 young adults was similarly tested; control data for children were taken from previously published work. The prevalence of atopy (any positive prick test) in children with CF was 48%. Sensitivity to grass pollens and house dust mite was no more common in these children (29%) than in a normal population (34%). Hypersensitivity to Aspergillus fumigatus was found in 35% of children with CF and was associated with severe lung disease. The parents had a normal pattern and prevalence of atopy. Exercise-induced airways obstruction was present in only 22% of children with CF; its association with severe lung disease rendered interpretation difficult. The parents had a normal response to exercise. Both hypersensitivity to A. fumigatus and exercise-induced airways lability had the features of acquired characteristics. There was nothing in the present study to support the hypothesis that the possession of a CF gene predisposed to atopy.

Clinical and biochemical studies in Engelmann's disease (progressive diaphyseal dysplasia)

The clinical and biochemical features of four adults with Engelmann's disease (Camurati-Engelmann disease; progressive diaphyseal dysplasia) are presented. One young patient, with a particularly severe form of the disease, is discussed in detail. Biochemical abnormalities were found in three of the patients. In two of them, one with localized hyperostosis and one with generalized bone disease, the only changes were an increase in the plasma alkaline phosphatase and urinary total hydroxyproline excretion. The most severely affected patients, who had had progressive and generalized bone disease from age two and a half years, also had persistent hypocalcaemia and hyperphosphataemia, a positive calcium balance, and a very low urine calcium excretion. It is suggested that some patients with Engelmann's disease may have a previously unrecognized metabolic disorder associated with increased retention of calcium and excessive bone formation. The possible role of abnormal phosphate metabolism in this increased formation of bone, and the relationship of Engelmann's disease to other hyperostoses, are discussed.

Urinary lithiasis in childhood in the Bristol clinical area

A series of 59 consecutive cases of urinary calculi in childhood is presented, being acquired from one local area (Bristol). These children were treated from 1950 to 1973. The peak presentation was in the 2nd and 3rd year of life, with a secondary peak in the 10th year. Anatomical (39%), metabolic (8.5%) or primary infective abnormalities (29%) were demonstrable, but 22% had to be left in an unsatisfactory "idiopathic classification''. The overall recurrence rate of 7% was reduced to 3.5% when those patients with cystinuria were excluded. The local water supply areas have been studied and a tentative association is suggested between patients and their environment when they live in an area where the water is not only hard but also alkaline (pHgreater than 8).

Urinary lithiasis in childhood in the Bristol clinical area

A series of 59 consecutive cases of urinary calculi in childhood is presented, being acquired from one local area (Bristol). These children were treated from 1950 to 1973. The peak presentation was in the 2nd and 3rd year of life, with a secondary peak in the 10th year. Anatomical (39%), metabolic (8.5%) or primary infective abnormalities (29%) were demonstrable, but 22% had to be left in an unsatisfactory "idiopathic classification". The overall recurrence rate of 7% was reduced to 3.5% when those patients with cystinuria were excluded. The local water supply areas have been studied and a tentative association is suggested between patients and their environment when they live in an area where the water is not only hard but also alkaline (pH greater than 8).