Effect of maximum exercise on left ventricular deformation and its correlation with cardiopulmonary exercise capacity in competitive athletes

BACKGROUND

Global longitudinal strain (GLS) and global myocardial work index (GWI) allow early detection of subclinical changes in left ventricular (LV) systolic function. The aim of the study was to investigate the immediate effects of maximum physical exercise by different exercise testing methods on early post exercise LV deformation parameters in competitive athletes and to analyze their correlation with cardiopulmonary exercise capacity.

METHODS

To reach maximum physical exercise, cardiopulmonary exercise testing (CPET) was performed by semi-recumbent ergometer in competitive handball players (n = 13) and by treadmill testing in competitive football players (n = 19). Maximum oxygen uptake (VO2max) indexed to body weight (relative VO2max) was measured in all athletes. Transthoracic echocardiography and blood pressure measurements were performed at rest and 5 min after CPET in all athletes. GLS, GWI and their changes before and after CPET (ΔGLS, ΔGWI) were correlated with (relative) VO2max.

RESULTS

In handball and football players, GLS and GWI did not differ significantly before and after CPET. There were no significant correlations between GLS and relative VO2max, but moderate correlations were found between ΔGWI and relative VO2max in handball (r = 0.631; P = 0.021) and football players (r = 0.592; P = 0.008). Furthermore, handball (46.7 ml/min*kg ± 4.7 ml/min*kg vs. 37.4 ml/min*kg ± 4.2; P = 0.004) and football players (58.3 ml/min*kg ± 3.7 ml/min*kg vs. 49.7 ml/min*kg ± 6.8; P = 0.002) with an increased ΔGWI after CPET showed a significant higher relative VO2max.

CONCLUSION

Maximum physical exercise has an immediate effect on LV deformation, irrespective of the used testing method. The correlation of relative VO2max with ΔGWI in the early post exercise period, identifies ΔGWI as an echocardiographic parameter for characterizing the current individual training status of athletes.

The impact of upright posture on left ventricular deformation in athletes

Besides LV ejection fraction (LVEF), global longitudinal strain (GLS) and global myocardial work index (GWI) are increasingly important for the echocardiographic assessment of left ventricular (LV) function in athletes. Since exercise testing is frequently performed on a treadmill, we investigated the impact of upright posture on GLS and GWI. In 50 male athletes (mean age 25.7 ± 7.3 years) transthoracic echocardiography (TTE) and simultaneous blood pressure measurements were performed in upright and left lateral position. LVEF (59.7 ± 5.3% vs. 61.1 ± 5.5%; P = 0.197) was not affected by athletes' position, whereas GLS (- 11.9 ± 2.3% vs. - 18.1 ± 2.1%; P < 0.001) and GWI (1284 ± 283 mmHg% vs. 1882 ± 247 mmHg%; P < 0.001) were lower in upright posture. Longitudinal strain was most frequently reduced in upright posture in the mid-basal inferior, and/or posterolateral segments. Upright posture has a significant impact on LV deformation with lower GLS, GWI and regional LV strain in upright position. These findings need to be considered when performing echocardiography in athletes.

Defining renal phenotype in Alström syndrome

BACKGROUND

Alström syndrome (AS) is a rare autosomal recessive ciliopathy with a wide spectrum of clinical features, including cone-rod retinal dystrophy, neuronal deafness, severe insulin resistance and major organ failure. The characteristics of renal disease in the syndrome have not been systematically described. The aim of this study is to define the onset and progression of renal disease in AS.

METHOD

Prospective observational cohort study.

SETTING AND PARTICIPANTS

Thirty-two adult subjects from a national specialist clinic in UK and 86 subjects from an international AS registry were studied.

OUTCOMES

First, an international registry cross-sectional study across all age groups to determine change in kidney function was performed. Secondly, a detailed assessment was carried out of adult AS patients with serial follow-up to determine incidence, aetiology and progression of renal disease.

ANALYTICAL APPROACH

Generalized estimating equations were used to evaluate the relationship between age and estimated glomerular filtration rate (eGFR). Associations between patient factors and eGFR levels were then assessed in the adult AS cohort.

RESULTS

The international registry study of the renal function of 118 subjects with AS (median age 21 years) showed a rapid decline with age, at an average of -16.7 and -10.9 mL/min/1.73 m2 per decade in males and females, respectively. In a UK national cohort of 32 patients with AS (median age 22 years), 20/32 (63%) had chronic kidney disease (CKD) Stage 3 or above based on eGFR <60 mL/min/1.73 m2 or evidence of albuminuria. Hyperuricaemia was noted in 25/32 (79%). Structural abnormalities such as nephrocalcinosis without hypercalcaemia and cysts were observed in 20/32 (63%) subjects. Lower urinary tract symptoms were frequent in 17/19 (70%) of AS patients. Histological evidence showed mixed tubulo-interstitial and glomerular disease.

CONCLUSIONS

This is the first study to demonstrate that renal disease is the hallmark of AS, which starts early and progresses with age, leading to a high prevalence of advanced CKD at young age. AS should be considered in the differential diagnosis of rare genetic renal diseases.

Responsiveness to oral prednisolone in severe asthma is related to the degree of eosinophilic airway inflammation

BACKGROUND

Patients with severe asthma appear relatively corticosteroid resistant. Corticosteroid responsiveness is closely related to the degree of eosinophilic airway inflammation. The extent to which eosinophilic airway inflammation in severe asthma responds to treatment with systemic corticosteroids is not clear.

OBJECTIVE

To relate the physiological and inflammatory response to systemic corticosteroids in asthma to disease severity and the baseline extent of eosinophilic inflammation.

METHODS

Patients with mild/moderate and severe asthma were investigated before and after 2 weeks of oral prednisolone (Clintrials.gov NCT00331058 and NCT00327197). We pooled the results from two studies with common protocols. The US study contained two independent centres and the UK one independent centre. The effect of oral corticosteroids on FEV₁ , Pc20, airway inflammation and serum cytokines was investigated. Baseline measurements were compared with healthy subjects.

RESULTS

Thirty-two mild/moderate asthmatics, 50 severe asthmatics and 35 healthy subjects took part. At baseline, both groups of asthmatics had a lower FEV₁ and Pc20 and increased eosinophilic inflammation compared to healthy subjects. The severe group had a lower FEV₁ and more eosinophilic inflammation compared to mild/moderate asthmatics. Oral prednisolone caused a similar degree of suppression of eosinophilic inflammation in all compartments in both groups of asthmatics. There were small improvements in FEV₁ and Pc20 for both mild/ moderate and severe asthmatics with a correlation between the baseline eosinophilic inflammation and the change in FEV₁ . There was a ~50% reduction in the serum concentration of CXCL10 (IP-10), CCL22 (MDC), CCL17 (TARC), CCL-2 (MCP-1) and CCL-13 (MCP-4) in both asthma groups after oral corticosteroids.

CONCLUSIONS AND CLINICAL RELEVANCE

Disease severity does not influence the response to systemic corticosteroids. The study does not therefore support the concept that severe asthma is associated with corticosteroid resistance. Only baseline eosinophilic inflammation was associated with the physiological response to corticosteroids, confirming the importance of measuring eosinophilic inflammation to guide corticosteroid use.

Sharpin Controls Osteogenic Differentiation of Mesenchymal Bone Marrow Cells

The cytosolic protein Sharpin is a component of the linear ubiquitin chain assembly complex, which regulates NF-κB signaling in response to specific ligands, such as TNF-α. Its inactivating mutation in chronic proliferative dermatitis mutation (Cpdm) mice causes multiorgan inflammation, yet this phenotype is not transferable into wild-type mice by hematopoietic stem cell transfer. Recent evidence demonstrated that Cpdm mice additionally display low bone mass, and that this osteopenia is corrected by Tnf deletion. Because the cellular mechanism underlying this pathology, however, was still undefined, we performed a thorough skeletal phenotyping of Cpdm mice on the basis of nondecalcified histology and cellular and dynamic histomorphometry. We show that the trabecular and cortical osteopenia in Cpdm mice is solely explained by impaired bone formation, whereas osteoclastogenesis is unaffected. Consistently, Cpdm primary calvarial cells display reduced osteogenic capacity ex vivo, and the same was observed with CD11b(-) bone marrow cells. Unexpectedly, short-term treatment of these cultures with TNF-α did not reveal an impaired molecular response in the absence of Sharpin. Instead, genome-wide and gene-specific expression analyses revealed that Cpdm mesenchymal cells display increased responsiveness toward TNF-α-induced expression of specific cytokines, such as CXCL5, IL-1β, and IL-6. Therefore, our data not only demonstrate that the skeletal defects of Cpdm mice are specifically caused by impaired differentiation of osteoprogenitor cells, they also suggest that increased cytokine expression in mesenchymal bone marrow cells contributes to the inflammatory phenotype of Cpdm mice.

The phenotypic and molecular genetic spectrum of Alström syndrome in 44 Turkish kindreds and a literature review of Alström syndrome in Turkey

Alström syndrome (ALMS) is an autosomal recessive disease characterized by multiple organ involvement, including neurosensory vision and hearing loss, childhood obesity, diabetes mellitus, cardiomyopathy, hypogonadism, and pulmonary, hepatic, renal failure and systemic fibrosis. Alström Syndrome is caused by mutations in ALMS1, and ALMS1 protein is thought to have a role in microtubule organization, intraflagellar transport, endosome recycling and cell cycle regulation. Here, we report extensive phenotypic and genetic analysis of a large cohort of Turkish patients with ALMS. We evaluated 61 Turkish patients, including 11 previously reported, for both clinical spectrum and mutations in ALMS1. To reveal the molecular diagnosis of the patients, different approaches were used in combination, a cohort of patients were screened by the gene array to detect the common mutations in ALMS1 gene, then in patients having any of the common ALMS1 mutations were subjected to direct DNA sequencing or next-generation sequencing for the screening of mutations in all coding regions of the gene. In total, 20 distinct disease-causing nucleotide changes in ALMS1 have been identified, eight of which are novel, thereby increasing the reported ALMS1 mutations by 6% (8/120). Five disease-causing variants were identified in more than one kindred, but most of the alleles were unique to each single patient and identified only once (16/20). So far, 16 mutations identified were specific to the Turkish population, and four have also been reported in other ethnicities. In addition, 49 variants of uncertain pathogenicity were noted, and four of these were very rare and probably or likely deleterious according to in silico mutation prediction analyses. ALMS has a relatively high incidence in Turkey and the present study shows that the ALMS1 mutations are largely heterogeneous; thus, these data from a particular population may provide a unique source for the identification of additional mutations underlying Alström Syndrome and contribute to genotype-phenotype correlation studies.

Influence of non-traumatic thoracic and lumbar vertebral fractures on sagittal spine alignment assessed by radiation-free spinometry

Due to missing indications for specific diagnostics, the majority of non-symptomatic vertebral fractures are not diagnosed. This study shows the ability of radiation-free spinometry to assess sagittal spine parameters to raise suspicion for new non-traumatic thoracic and lumbar vertebral fractures and indicate specific diagnostics.

INTRODUCTION

The primary aim of this study was to investigate the accuracy of radiation-free spinometry to predict new non-traumatic vertebral fractures (VF) by the assessment of thoracic kyphosis (TK), lumbar lordosis (LL), and trunk inclination.

METHODS

Three hundred sixty-one patients (278 females and 83 males; age, 67.0 ± 8.6 years) were enrolled. In 86 women and 24 men, at least one non-traumatic VF was confirmed by radiography, MRI, and/or CT. Spinometry (video rasterstereography) was used to assess TK, LL, and trunk inclination. Receiver operating characteristic (ROC) and multivariate logistic regression analyses were performed to test the influence of age, sex, number, location, and grade of fractures on sagittal spine alignment.

RESULTS

TK, LL, and trunk inclination were associated with advancing age (p < 0.05). Patients with prevalent thoracic and lumbar VFs showed increased TK (p < 0.001), decreased LL (p < 0.001), and increased trunk inclination (p < 0.001) in comparison to patients without VFs. ROC analysis revealed that the combination of TK and LL presented with the best predictive accuracy to raise suspicion for new grade 2 or grade 3 VFs in the thoracic and the lumbar spine (AUC, 0.752-0.771). Odds ratio (OR) showed an increased risk for VFs with increased TK (OR, 1.05-1.11; p < 0.001) and LL (1.05-1.07; p < 0.001) in specified regions of interest. A TK <50° (sensitivity, 88-100 %; specificity, 23-25 %) and LL (78-92 %; 24-27 %) were considered as appropriate cutoffs for future screening.

CONCLUSION

Spinometry showed better predictive accuracy than historical height loss. Severe changes of TK and LL may help to raise suspicion of new VFs radiation-free and indicate proper diagnostics, such as radiographs, MRI, or CT.

Osteopetrosis, osteopetrorickets and hypophosphatemic rickets differentially affect dentin and enamel mineralization

Osteopetrosis (OP) is an inherited disorder of defective bone resorption, which can be accompanied by impaired skeletal mineralization, a phenotype termed osteopetrorickets (OPR). Since individuals with dysfunctional osteoclasts often develop osteomyelitis of the jaw, we have analyzed, if dentin and enamel mineralization are differentially affected in OP and OPR. Therefore, we have applied non-decalcified histology and quantitative backscattered electron imaging (qBEI) to compare the dental phenotypes of Src(-/-), oc/oc and Hyp(-/0) mice, which serve as models for OP, OPR and hypophosphatemic rickets, respectively. While both, Src(-/-) and oc/oc mice, were characterized by defects of molar root formation, only oc/oc mice displayed a severe defect of dentin mineralization, similar to Hyp(-/0) mice. Most importantly, while enamel thickness was not affected in either mouse model, the calcium content within the enamel phase was significantly reduced in oc/oc, but not in Src(-/-) or Hyp(-/0) mice. Taken together, these data demonstrate that dentin and enamel mineralization are differentially affected in Src(-/-) and oc/oc mice. Moreover, since defects of dental mineralization may trigger premature tooth decay and thereby osteomyelitis of the jaw, they further underscore the importance of discriminating between OP and OPR in the respective individuals.

Spontaneous osteonecrosis of the knee (SONK)

PURPOSE

Spontaneous osteonecrosis of the knee (SONK/Morbus Ahlback) mainly affects the medial condyle of elderly women. It is assumed that localized vascular insufficiency leads to necrosis of the subchondral bone with subsequent disruption of the nutrition supply to the cartilage above. The aetiology remains unclear in detail. Operative treatment procedures compete against non-operative strategies, whereas the outcome is unpredictable in many cases.

METHOD

A consecutive case series of five patients suffering from SONK was analysed. All patients underwent a clinical examination, magnetic resonance imaging (MRI) and dual-energy X-ray absorptiometry scan, as well as laboratory analyses and visual analogue scale (VAS) evaluation. Our treatment regime is based on high-dose vitamin D administered orally and intravenous application of 3 mg ibandronate two times within 8 weeks. Another 8 weeks later, all patients were followed up including a follow-up MRI.

RESULTS

Within 4 weeks, all patients were free of symptoms. The MRI follow-up showed remission of the bone marrow oedema in every case studied. VAS decreased significantly from 7.4 ± 1.0 pre-interventional to 0.8 ± 1.0 post-interventional. No allergic reactions or other side effects were documented.

CONCLUSION

We showed that our treatment regime not only eliminated the pathological findings in the MRI of all cases studied, but also decreased the pain level and functional limitations within a short-time period.

LEVEL OF EVIDENCE

IV.

Human apolipoprotein E isoforms differentially affect bone mass and turnover in vivo

The primary role of apolipoprotein E (apoE) is to mediate the cellular uptake of lipoproteins. However, a new role for apoE as a regulator of bone metabolism in mice has recently been established. In contrast to mice, the human APOE gene is characterized by three common isoforms APOE ε2, ε3, and ε4 that result in different metabolic properties of the apoE isoforms, but it remains controversial whether the APOE polymorphism influences bone traits in humans. To clarify this, we investigated bone phenotypes of apoE knock-in (k.i.) mice, which express one human isoform each (apoE2 k.i., apoE3 k.i., apoE4 k.i.) in place of the mouse apoE. Analysis of 12-week-old female k.i. mice revealed increased levels of biochemical bone formation and resorption markers in apoE2 k.i. animals as compared to apoE3 k.i. and apoE4 k.i., with a reduced osteoprotegerin (OPG)/receptor activator of NF-κB ligand (RANKL) ratio in apoE2 k.i., indicating increased turnover with prevailing resorption in apoE2 k.i. Accordingly, histomorphometric and micro-computed tomography (µCT) analyses demonstrated significantly lower trabecular bone mass in apoE2 than in apoE3 and apoE4 k.i. animals, which was reflected by a significant reduction of lumbar vertebrae maximum force resistance. Unlike trabecular bone, femoral cortical thickness, and stability was not differentially affected by the apoE isoforms. To extend these observations to the human situation, plasma from middle-aged healthy men homozygous for ε2/ε2, ε3/ε3, and ε4/ε4 (n = 21, n = 80, n = 55, respectively) was analyzed with regard to bone turnover markers. In analogy to apoE2 k.i. mice, a lower OPG/RANKL ratio was observed in the serum of ε2/ε2 carriers as compared to ε3/ε3 and ε4/ε4 individuals (p = 0.02 for ε2/ε2 versus ε4/ε4). In conclusion, the current data strongly underline the general importance of apoE as a regulator of bone metabolism and identifies the APOE ε2 allele as a potential genetic risk factor for low trabecular bone mass and vertebral fractures in humans.

High bone mass in the STR/ort mouse results from increased bone formation and impaired bone resorption and is associated with extramedullary hematopoiesis

We here describe the novel high bone mass phenotype in STR/ort mice that leads to increased bone masses of cortical and trabecular bone and is associated with elevated osteoblast activity and impaired osteoclast function alike. Comparison of STR/ort and C57BL/6 mice reveals an increase in trabecular bone volumes of the vertebrae and at femoral metaphysis. In the females, this difference is significant as early as 2 months of age and at 9 months the females by far exceed their age matched males in all parameters measured. The increase in cortical bone mass at femoral diaphysis results from an apposition to the endosteal surface, it is significant for both sexes as early as 1 month of age and leads to bone marrow compression and extramedullary hematopoiesis. Altered activities of both, the osteoblast and the osteoclast contribute to the high bone mass and collectively this phenotype supports a multifactorial pathogenesis. Moreover, the spontaneous development of osteoarthritis in male STR/ort mice is suggestive of a tight correlation between trabecular bone mass and the development of degenerative changes of the articular cartilage.

Pharmacological estrogen administration causes a FSH-independent osteo-anabolic effect requiring ER alpha in osteoblasts

Postmenopausal osteoporosis is characterized by declining estrogen levels, and estrogen replacement therapy has been proven beneficial for preventing bone loss in affected women. While the physiological functions of estrogen in bone, primarily the inhibition of bone resorption, have been studied extensively, the effects of pharmacological estrogen administration are still poorly characterized. Since elevated levels of follicle-stimulating hormone (FSH) have been suggested to be involved in postmenopausal bone loss, we investigated whether the skeletal response to pharmacological estrogen administration is mediated in a FSH-dependent manner. Therefore, we treated wildtype and FSHβ-deficicent (Fshb^−/−) mice with estrogen for 4 weeks and subsequently analyzed their skeletal phenotype. Here we observed that estrogen treatment resulted in a significant increase of trabecular and cortical bone mass in both, wildtype and Fshb^−/− mice. Unexpectedly, this FSH-independent pharmacological effect of estrogen was not caused by influencing bone resorption, but primarily by increasing bone formation. To understand the cellular and molecular nature of this osteo-anabolic effect we next administered estrogen to mouse models carrying cell specific mutant alleles of the estrogen receptor alpha (ERα). Here we found that the response to pharmacological estrogen administration was not affected by ERα inactivation in osteoclasts, while it was blunted in mice lacking the ERα in osteoblasts or in mice carrying a mutant ERα incapable of DNA binding. Taken together, our findings reveal a previously unknown osteo-anabolic effect of pharmacological estrogen administration, which is independent of FSH and requires DNA-binding of ERα in osteoblasts.

Application of ex vivo micro-computed tomography for assessment of in vivo fluorescence and plain radiographic imaging for monitoring bone metastases and osteolytic lesions

The intracardiac injection model is a commonly used in vivo model to test therapeutic response in bone metastases. However, few studies have critically compared the performance of different imaging methods in terms of sensitivity and quantitative assessment of osteolytic lesions. We performed in vivo optical and plain radiographic imaging of bone metastases followed by high-sensitivity ex vivo micro-computed tomography (micro-CT) imaging. This approach allowed for quantitative assessment of in vivo imaging techniques using fluorescence and plain radiography. Comparison of lesions detected in vivo by fluorescent optical imaging with ex vivo micro-CT revealed that the limited spatial resolution of fluorescent optical imaging may underestimate the number of bone metastases. Radiography was compared with micro-CT for the detection of osteolytic lesions. When using dichotomous yes/no grading, there was a 64% agreement in detection of osteolytic lesions. When subjective semiquantitative grading methods were used to assess the extent of osteolytic lesions, a positive association between the micro-CT grades and the square root of the radiography-based grades was observed (p < 0.05). Micro-CT also showed a significant association with fluorescent optical values; however, no such association was observed between lesion scores based on radiographs and those based on fluorescent imaging. The findings reveal an approximate two-fold sensitivity for micro-CT compared to plain radiography in the detection of osteolytic lesions. Significant associations between micro-CT-based osteolytic lesion grade and tumor growth characterized by increased fluorescent area document the value of these two techniques for the assessment of osteolytic bone metastases.

Control of bone formation by the serpentine receptor Frizzled-9

Although Wnt signaling in osteoblasts is of critical importance for the regulation of bone remodeling, it is not yet known which specific Wnt receptors of the Frizzled family are functionally relevant in this process. In this paper, we show that Fzd9 is induced upon osteoblast differentiation and that Fzd9(-/-) mice display low bone mass caused by impaired bone formation. Our analysis of Fzd9(-/-) primary osteoblasts demonstrated defects in matrix mineralization in spite of normal expression of established differentiation markers. In contrast, we observed a reduced expression of chemokines and interferon-regulated genes in Fzd9(-/-) osteoblasts. We also identified the ubiquitin-like modifier Isg15 as one potential downstream mediator of Fzd9 in these cells. Importantly, our molecular analysis further revealed that canonical Wnt signaling is not impaired in the absence of Fzd9, thus explaining the absence of a bone resorption phenotype. Collectively, our results reveal a previously unknown function of Fzd9 in osteoblasts, a finding that may have therapeutic implications for bone loss disorders.

Short-term activation of liver X receptors inhibits osteoblasts but long-term activation does not have an impact on murine bone in vivo

Liver X receptors (LXRs) are nuclear receptors that play a crucial role in the transcriptional control of lipid metabolism. Pharmacological LXR activation is an attractive concept for the treatment of atherosclerosis. Genetic LXR deficiency in mice has been shown to have an effect on bone turnover and structure and LXR activation is known to influence the osteogenic differentiation of bone marrow stromal cells. Therefore, therapeutic pharmacological LXR activation may have relevant effects on bone. Here, using two synthetic LXR ligands, T0901317 and GW3965, we investigated the effect of LXR activation on murine osteoblasts and the influence of long-term LXR activation on bone in vivo in mice. Short term (48 h) in vitro treatment of primary murine osteoblasts with T0901317 resulted in a dose-dependent decrease of osteocalcin and alkaline phosphatase mRNA and protein. In vivo, a 6-day treatment of C57BL/6J mice with T0901317 led to a 40% reduction of serum osteocalcin concentrations. Long-term (12-week) oral administration of T0901317 or GW3965 influenced the expression of established LXR target genes in liver and intestine, but did not alter trabecular and cortical bone structure or bone turnover as determined by total skeleton radiography, histomorphometric analysis of lumbar vertebral trabecular bone, micro CT analysis of femur cortical bone and biochemical determination of bone formation and resorption markers. We conclude that short-term pharmacological LXR activation has the potential to profoundly influence osteoblast function, but that long-term LXR activation in vivo has no adverse effects on the murine skeleton.

Increased trabecular bone formation in mice lacking the growth factor midkine

Midkine (Mdk) and pleiotrophin (Ptn) comprise a family of heparin-binding growth factors known primarily for their effects on neuronal cells. Since transgenic mice overexpressing Ptn have been reported to display increased bone density, we have previously analyzed Ptn-deficient mice but failed to detect any abnormality of skeletal development and remodeling. Together with the finding that Mdk expression increases in the course of primary osteoblast differentiation, we reasoned that Mdk, rather than Ptn, could play a physiologic role in bone formation. Here, we show that Mdk-deficient mice display an increased trabecular bone volume at 12 and 18 months of age, accompanied by cortical porosity. Histomorphometric quantification demonstrated an increased bone-formation rate compared with wild-type littermates, whereas bone resorption was differentially affected in trabecular and cortical bone of Mdk-deficient mice. To understand the effect of Mdk on bone formation at the molecular level, we performed a genome-wide expression analysis of primary osteoblasts and identified Ank and Enpp1 as Mdk-induced genes whose decreased expression in Mdk-deficient osteoblasts may explain, at least in part, the observed skeletal phenotype. Finally, we performed ovariectomy and observed bone loss only in wild-type but not in Mdk-deficient animals. Taken together, our data demonstrate that Mdk deficiency, at least in mice, results in an increased trabecular bone formation, thereby raising the possibility that Mdk-specific antagonists might prove beneficial in osteoporosis therapy.

Negative regulation of bone formation by the transmembrane Wnt antagonist Kremen-2

Wnt signalling is a key pathway controlling bone formation in mice and humans. One of the regulators of this pathway is Dkk1, which antagonizes Wnt signalling through the formation of a ternary complex with the transmembrane receptors Krm1/2 and Lrp5/6, thereby blocking the induction of Wnt signalling by the latter ones. Here we show that Kremen-2 (Krm2) is predominantly expressed in bone, and that its osteoblast-specific over-expression in transgenic mice (Col1a1-Krm2) results in severe osteoporosis. Histomorphometric analysis revealed that osteoblast maturation and bone formation are disturbed in Col1a1-Krm2 mice, whereas bone resorption is increased. In line with these findings, primary osteoblasts derived from Col1a1-Krm2 mice display a cell-autonomous differentiation defect, impaired canonical Wnt signalling and decreased production of the osteoclast inhibitory factor Opg. To determine whether the observed effects of Krm2 on bone remodeling are physiologically relevant, we analyzed the skeletal phenotype of 24 weeks old Krm2-deficient mice and observed high bone mass caused by a more than three-fold increase in bone formation. Taken together, these data identify Krm2 as a regulator of bone remodeling and raise the possibility that antagonizing KRM2 might prove beneficial in patients with bone loss disorders.

Delayed ultraviolet erythema not suppressed by oral prednisolone: a randomized crossover study

BACKGROUND

The anti-inflammatory potency of topical dermatological corticosteroids in suppressing ultraviolet (UV) erythema is routinely measured. No such model exists to assess the potency of systemically administered steroids.

OBJECTIVE

To determine whether or not suppression of delayed UV erythema by a systemic corticosteroid could provide a useful model for assessing the anti-inflammatory potency of systemic corticosteroids.

METHODS

We conducted a randomized, placebo-controlled, patient and assessor blinded, crossover study of oral prednisolone effects on the delayed UV-induced erythemal response in normal subjects. Six healthy volunteers were phototested with a xenon arc monochromator and then dosed with 30 mg of oral prednisolone or matching placebo daily for 4 days. Repeat phototesting was performed on the 4th day of dosing. The minimal erythema dose (MED) was assessed immediately after test UV doses were administered and 24 h later. After a 2-week washout period, the dosing and testing were repeated in a crossover fashion.

RESULTS

A suppression index (SI) [1/(baseline MED value divided by on prednisolone/placebo value)] allowed comparison of the degree of suppression on and off prednisolone. Oral prednisolone did not significantly suppress the threshold UV erythema response (MED). We may have missed small effects in this study and possibly a larger dose or a longer duration of corticosteroid would have had an effect. Possibly, assessment of corticosteroid potency in suppressing established UV erythema rather than on the development of threshold erythema would have yielded different results.

CONCLUSION

The threshold UV erythema suppression model assessed in this study could not distinguish between oral prednisolone and placebo. This UV-erythema suppression test system is not promising as a model to test the anti-inflammatory potency of systemic steroids.

Impaired gastric acidification negatively affects calcium homeostasis and bone mass

Activation of osteoclasts and their acidification-dependent resorption of bone is thought to maintain proper serum calcium levels. Here we show that osteoclast dysfunction alone does not generally affect calcium homeostasis. Indeed, mice deficient in Src, encoding a tyrosine kinase critical for osteoclast activity, show signs of osteopetrosis, but without hypocalcemia or defects in bone mineralization. Mice deficient in Cckbr, encoding a gastrin receptor that affects acid secretion by parietal cells, have the expected defects in gastric acidification but also secondary hyperparathyroidism and osteoporosis and modest hypocalcemia. These results suggest that alterations in calcium homeostasis can be driven by defects in gastric acidification, especially given that calcium gluconate supplementation fully rescues the phenotype of the Cckbr-mutant mice. Finally, mice deficient in Tcirg1, encoding a subunit of the vacuolar proton pump specifically expressed in both osteoclasts and parietal cells, show hypocalcemia and osteopetrorickets. Although neither Src- nor Cckbr-deficient mice have this latter phenotype, the combined deficiency of both genes results in osteopetrorickets. Thus, we find that osteopetrosis and osteopetrorickets are distinct phenotypes, depending on the site or sites of defective acidification.

The rapamycin analogue SDZ RAD attenuates bleomycin-induced pulmonary fibrosis in rats

Pulmonary fibrosis is characterized by excessive deposition of extracellular matrix proteins within the pulmonary interstitium. The new macrolide immunosuppressant SDZ RAD, a rapamycin analogue, inhibits growth-factor dependent proliferation of mesenchymal cells and might therefore be of therapeutic interest for the treatment of fibrotic lung disease. In this study the effect of SDZ RAD on lung-collagen accumulation in the bleomycin model of pulmonary fibrosis in rats was investigated. SDZ RAD (2.5 mg x kg(-1) x day(-1)) or drug vehicle were administered orally by daily gavage. Successful dosing was confirmed by measuring splenic weight. Total lung-collagen content was measured by high-performance liquid chromatographic quantitation of hydroxyproline. In animals given bleomycin and drug vehicle, total lung collagen was increased by 182+/-11% (mean+/-SEM) compared with saline controls at 14 days (p<0.001). The increase in lung-collagen accumulation was reduced by 75+/-12% (p<0.01) in animals given SDZ RAD and was accompanied by a concomitant 56+/-6% (p<0.001) reduction in lung weight. SDZ RAD is currently in clinical trials for the prevention of solid organ graft rejection, another condition characterized by excessive extracellular matrix production. The authors propose that SDZ RAD warrants evaluation as a novel therapeutic agent for fibrotic lung disease.

Direct thrombin inhibition reduces lung collagen, accumulation, and connective tissue growth factor mRNA levels in bleomycin-induced pulmonary fibrosis

Dramatic activation of the coagulation cascade has been extensively documented for pulmonary fibrosis associated with acute and chronic lung injury. In addition to its role in hemostasis, thrombin exerts profibrotic effects via activation of the major thrombin receptor, protease-activated receptor-1. In this study, we examined the effect of the direct thrombin inhibitor, UK-156406 on fibroblast responses in vitro and on bleomycin-induced pulmonary fibrosis in rats. UK-156406 significantly inhibited thrombin-induced fibroblast proliferation, procollagen production, and connective tissue growth factor (CTGF) mRNA levels when used at equimolar concentration to the protease. Thrombin levels in bronchoalveolar lavage fluid and expression of thrombin and protease-activated receptor-1 in lung tissue were increased after intratracheal instillation of bleomycin. The characteristic doubling in lung collagen in bleomycin-treated animals (38.4 +/- 2.0 mg versus 17.1 +/- 1.4 mg, P < 0.01) was preceded by significant elevations in alpha1(I) procollagen and CTGF mRNA levels (3.0 +/- 0.4-fold and 6.3 +/- 0.4-fold respectively, (P < 0.01), and total inflammatory cell number. UK-156406, administered at an anticoagulant dose, attenuated lung collagen accumulation in response to bleomycin by 35 +/- 12% (P < 0.05), inhibited alpha1(I) procollagen and CTGF mRNA levels by 50% and 35%, respectively (P < 0.05), but had no effect on inflammatory cell recruitment. This is the first report showing that direct thrombin inhibition abrogates lung collagen accumulation in bleomycin-induced pulmonary fibrosis.

Medical-care costs associated with posttraumatic stress disorder in Vietnam veterans

OBJECTIVE

This study examined the relationship between medical-care costs of Vietnam veterans and predictor factors, including posttraumatic stress disorder (PTSD).

METHOD

We merged medical-care cost data from the Department of Veterans' Affairs and the Health Insurance Commission with data from an epidemiological study of 641 Australian Vietnam veterans. Posttraumatic stress disorder and other factors were examined as predictors of medical-care cost using regression analysis.

RESULTS

We found that a diagnosis of PTSD was associated with medical costs 60% higher than average. Those costs appeared to be partly associated with higher treatment costs for physical conditions in those with PTSD and also related mental health comorbidities. Major predictors of medical-care cost were age ($137 per year for each 5-year increase in age) and number of diagnoses reported ($81 to $112 per year for each diagnosis). Mental health factors such as depression ($14 per year for each symptom reported) and anxiety ($27 per year for each symptom reported) were also important predictors.

CONCLUSIONS

The findings indicate that, however they are incurred, high healthcare and, presumably, also economic and personal costs are associated with PTSD. There is an important social obligation as well as substantial economic reasons to deal with these problems. From both perspectives, continued efforts to identify and implement effective prevention and treatment programs are warranted.

Fibroproliferation occurs early in the acute respiratory distress syndrome and impacts on outcome

The fibroproliferative phase of acute respiratory distress syndrome (ARDS) has traditionally been regarded as a late event but recent studies that suggest increased lung collagen turnover within 24 h of diagnosis challenge this view. We hypothesized that fibroproliferation is initiated early in ARDS, characterized by the presence of fibroblast growth factor activity in the lung and would relate to clinical outcome. Patients fulfilling American/European Consensus Committee criteria for ARDS and control patients ventilated for non-ARDS respiratory failure underwent bronchoalveolar lavage (BAL) and serum sampling within 24 h of diagnosis and again at 7 d. The ability of BAL fluid (BALF) to stimulate human lung fibroblast proliferation in vitro was examined in relation to concentrations of N-terminal peptide for type III procollagen (N-PCP-III) in BALF/serum and clinical indices. At 24 h, ARDS lavage fluid demonstrated potent mitogenic activity with a median value equivalent to 70% (range 31-164) of the response to serum, and was significantly higher than control lavage (32% of serum response, range 11-42; p < 0.05). At 24 h, serum N-PCP-III concentrations were elevated in the ARDS group compared with control patients (2.8 U/ml; range 0.6-14.8 versus 1.1 U/ml; range 0.4-3.7, p < 0.0001) as were BALF N-PCP-III concentrations (2.9 U/ml; range 0. 6-11.4 versus 0.46 U/ ml; range 0.00-1.63, p < 0.01). In addition, BALF N-PCP-III concentrations at 24 h were significantly elevated in nonsurvivors of ARDS compared with survivors (p < 0.05). At 7 d, the mitogenic activity remained elevated in the ARDS group compared with control (p < 0.05) and was also significantly higher in ARDS nonsurvivors compared with survivors (67%; range 45-120 versus 31%; range 16-64, p < 0.05). These data are consistent with the hypothesis that fibroproliferation is an early response to lung injury and an important therapeutic target.

Current strategies for mechanical ventilation in acute lung injury

Non-invasive modes of ventilation may be adequate for some patients with less severe acute lung injury (ALI) but invasive positive pressure ventilation is usually required. Ventilation strategies for such patients have changed significantly in recent years, as it is has become increasingly apparent that the process of ventilation itself may contribute to lung injury.

Distress experienced by participants during an epidemiological survey of posttraumatic stress disorder

We examined the potential for epidemiological studies of mental disorders, specifically of posttraumatic stress disorder (PTSD), to cause further harm to participants involved. Of 1,000 randomly selected Australian Vietnam veterans, 641 agreed to participate in an epidemiological survey. Participants were asked about distress experienced during the interview when traumatic events were raised. Significant distress attributed to the interview was reported by 75.3% of those with current PTSD, 56.5% of those with past PTSD, and 20.6% of those with no PTSD diagnosis. Distress did not affect participants' use of medical services following the interview nor did it affect their willingness to continue participating in the study. We concluded that research interviews about PTSD may cause short-term distress, but found no evidence of long-term harm.

Angiotensin II is mitogenic for human lung fibroblasts via activation of the type 1 receptor

The expression of renin-angiotensin system components and the elevation of angiotensin-converting enzyme (ACE) in a number of fibrotic lung diseases suggests angiotensin II (AII) could play a role in the pathogenesis of pulmonary fibrosis. However, the effect of AII on lung fibroblasts has not previously been assessed and the mechanisms by which AII induces cell proliferation in mesenchymal cells are not fully understood. We have examined the ability of AII to stimulate fetal and adult human lung fibroblast proliferation in vitro. In particular, we have assessed the receptor subtypes involved and the possible autocrine role of transforming growth factor beta (TGF-beta) and platelet-derived growth factor (PDGF), two recognized fibroblast mitogens. Angiotensin type 1 (AT1), but not type 2, receptors were identified on fetal and adult human lung fibroblasts by immunocytochemistry. AII (1 microM) increased DNA synthesis (determined by [(3)H]thymidine incorporation) in fetal and adult cells by 211 +/- 18% and 150 +/- 14%, respectively (p < 0.01), and was inhibited by a specific AT1 receptor antagonist, Losartan (74 +/- 14%). A proliferative response to AII was confirmed by direct cell counts. Subsequently, fibroblasts were incubated with neutralizing antibodies to TGF-beta and PDGF. Anti-TGF-beta antibodies inhibited AII-induced DNA synthesis by 73 +/- 13%. However, no effect was seen with anti-PDGF antibodies. In conclusion, we have shown that angiotensin II induces human lung fibroblast proliferation in vitro via activation of the AT1 receptor and involves the autocrine action of TGF-beta.

Adult familial cryptogenic fibrosing alveolitis in the United Kingdom

BACKGROUND

Familial cases of cryptogenic fibrosing alveolitis (CFA) have previously been reported; however, the prevalence and genetic background of this disorder are not known. The clinical and epidemiological findings of 25 families identified within the UK are reported.

METHODS

Adult pulmonary physicians in the UK were asked to identify all families under their care in which two or more individuals had been diagnosed with fibrosing alveolitis of unknown cause. A detailed structured questionnaire was sent to each proband to delineate possible environmental/occupational exposures and to obtain complete pedigree data. Physicians were also asked to provide clinical and diagnostic information.

RESULTS

Twenty five families were identified comprising 67 cases. Suitable data for analysis were available for 21 families (57 cases). The male:female ratio was 1. 75:1 (p<0.05). A high resolution computed tomographic (HRCT) scan was performed in 93% and a diagnosis of CFA confirmed on biopsy specimens in 32%. The mean age at diagnosis was 55.5 (2.5) years. Fifty percent of cases were ever smokers and 18% had been diagnosed as asthmatic. Exposure to known fibrogenic agents was recorded by 36% of patients. Clinical signs/symptoms and histological findings were indistinguishable from non-familial cases.

CONCLUSIONS

This study represents the largest cohort of familial CFA cases reported to date and confirms a prevalence of 1.34 cases per 10(6) in the UK population. Although rare, such cases represent an important subgroup in which a genetic susceptibility to pulmonary fibrosis is particularly evident. Familial patients are younger at diagnosis but otherwise indistinguishable from non-familial cases. The mode of inheritance is as yet unclear but a number of genetic loci are likely to be involved and are the subject of ongoing studies.

Combat, dissociation, and posttraumatic stress disorder in Australian Vietnam veterans

The specificity of various wartime stressors for different posttraumatic stress disorder (PTSD) symptoms is inconsistently reported in the literature. Combat, wounding, and peritraumatic dissociation have not been assessed together in their effects on each of the various PTSD symptom clusters. This cohort study of a random sample of male Australian Army Vietnam veterans yielded psychiatric assessments of 641 subjects. PTSD measures comprised symptom criteria for reexperiencing, numbing and avoidance, hyperarousal, and PTSD diagnosis both lifetime and current within the past month. Logistic regression is used to examine the effects of combat, wounding, and peritraumatic dissociation together on PTSD. Combat experiences comprised four components derived from a principal components analysis of combat experiences: direct combat exposure, exposure to death and injury, exposure to civilian death and injury, and exposure to mutilation. Each was differentially related to reexperiencing, avoidance, hyperarousal, and PTSD diagnosis. Being wounded was not related to lifetime or current PTSD and peritraumatic dissociation was related to all diagnostic components of PTSD in the presence of other variables.

Posttraumatic stress disorder and other predictors of health care consumption by Vietnam veterans

A total of 641 randomly selected Australian veterans of the Vietnam War were interviewed about their use of health care in the previous two weeks to determine what factors contributed to health care consumption. Seventy-three variables were examined by univariate linear regression and then grouped into seven categories relating to age, physical and mental health, predisposition to posttraumatic stress disorder (PTSD), deployment and repatriation experiences, and membership in veterans groups. PTSD was associated with an additional cost of $79 in health care for the two-week period. Each physical diagnosis was associated with an additional $28. Alcohol consumption was not related to health care costs. Other important variables contributing to costs were depression, educational status, the quality of the repatriation experience, and social support.

DRG cost weights--getting it right

Inadequate cost weights are a major problem in casemix funding systems. Clinicians should understand the basis for the cost weights underpinning the hospital payment system in their State and their own hospital. Clinician managers need valid patient costing data if they are to benchmark and improve cost-effectiveness while maintaining and enhancing quality. The cost model approach for determining cost weights has inherent limitations, and, the alternative, detailed patient costing, requires efficient hospital information technology systems. A simplified approach to patient costs, which uses existing hospital data systems, may be useful for smaller hospitals. A better classification system and funding formulas incorporating reliable cost weights derived from patient costing should overcome many of the deficiencies in the current casemix payments systems.

Postwar experiences and treatment-seeking behavior in a community counselling setting

Previous research investigating the impact of postwar experiences on Vietnam veterans has focused on veteran morbidity. This emphasis has meant that the impact of these factors on treatment-seeking behavior has received little empirical attention. This study examined the association between postwar factors and treatment-seeking behavior in a sample of 692 Australian Vietnam veterans. Logistic regression analyses were used to compute the odds ratios associated with postwar experiences and self-referral to a community-based counselling service. Results suggest that veterans who reported experiencing negative feelings toward others when they first arrived home were more likely to seek treatment. Other factors, such as a veteran's perception of societal attitudes and the reception they received, were not associated with treatment-seeking behavior.

Effect of endothelin receptor antagonists (BQ-485, Ro 47-0203) on collagen deposition during the development of bleomycin-induced pulmonary fibrosis in rats

Previous evidence suggests a role for endothelin-1 (ET-1) in the pathogenesis of pulmonary fibrosis. To determine if ET-1 regulates collagen deposition in pulmonary fibrosis, we examined the effect of the non-selective ETA and ETB receptor antagonist bosentan (Ro 47-0203), and a selective ETA receptor antagonist, BQ-485, on collagen deposition during the development of bleomycin-induced pulmonary fibrosis in rats. Lung collagen content, derived from measurements of hydroxyproline and expressed as mg collagen/lung, was increased in the bleomycin-treated animals by day 7 (bleomycin, 22.88+/-1.46; control 18.50+/-0.98; P<0.05), continued to increase up to day 14 (bleomycin, 38.80+/-2.17; control 22.57+/-0.77; P<0.001) and then remained constant to 21 days. Daily treatment by gavage with bosentan (100 mg/kg) did not prevent the increase in collagen deposition induced by instillation of bleomycin at any of the times measured. Continuous administration of BQ-485, by subcutaneously implanted minipump (7.5 mg/day), also failed to prevent the bleomycin-induced collagen deposition at 14 days. These findings suggest that ET-1 does not modulate collagen deposition during the development of bleomycin-induced pulmonary fibrosis. Further studies are required to assess whether endothelin receptor antagonists modulate other components of the fibrotic response or play a role in man.

Posttraumatic stress disorder and comorbidity in Australian Vietnam veterans: risk factors, chronicity and combat

OBJECTIVE

The objective of this study was to examine the relationship between combat-related posttraumatic stress disorder (PTSD) and comorbid DSM-III-R psychiatric diagnoses to determine commonalities in risk factors, relative onsets and the role of combat exposure.

METHOD

An epidemiological cohort study using standardised psychiatric, social and health interviews was undertaken with a national random sample of male Australian Army Vietnam veterans. Interviews and searches of military records yielded risk factors for PTSD, which were examined for association with each psychiatric diagnosis. Relative onsets of PTSD and each Diagnostic Interview Schedule diagnosis were compared. Comorbidity odds ratios were adjusted for combat exposure effects using logistic regression, and the relation between each diagnosis and combat was assessed after controlling for PTSD.

RESULTS

Commonality of risk factor profile was evident for several diagnoses, and for many their onset preceded PTSD onset. Combat was independently related to only a few diagnoses after controlling for PTSD, and PTSD remained strongly associated with several conditions after controlling for combat exposure.

CONCLUSIONS

The analysis suggests that the disorders that may constitute risk factors or vulnerabilities for PTSD comprise depression and dysthymia, antisocial personality disorder, agoraphobia and simple phobia, while those that may be consequent on PTSD are panic and generalised anxiety disorder, drug use disorders and somatoform pain disorder. Alcohol and drug use disorders and social phobia may have a mixed aetiology, while obsessive-compulsive disorder may be serendipitously related to PTSD through an association with risk of combat. Gambling disorder is unrelated.

Risk factors for posttraumatic stress disorder in Australian Vietnam veterans

OBJECTIVE

The aims of this paper are to determine the risk factors for combat-related posttraumatic stress disorder (PTSD) and to examine the relative contribution of pre-military factors, pre-trauma psychiatric diagnoses, military factors such as combat posting, and combat and casualty stress exposure.

METHOD

An epidemiological cohort study using standardised psychiatric, social and health interviews was undertaken with a national random sample of male Australian Army Vietnam veterans. Multivariate logistic regression was used to examine the relative contribution of factors derived from interview and from military records in four categories: pre-enlistment circumstances including home life, education, major life stress; pre-Vietnam psychiatric diagnoses; military experiences before and during Vietnam; and combat and stress experiences.

RESULTS

Of the 128 data items examined, significant associations were found for 39, in addition to combat stress. Pre-enlistment items accounted for about 3% of the deviance towards PTSD diagnosis, pre-enlistment psychiatric diagnosis about 13%, military variables about 7% and combat stress about 18%; all factors together accounted for 42%.

CONCLUSIONS

The results confirm that pre-military and military variables make only a small but significant contribution to PTSD either alone or after controlling for combat stress; that psychiatric diagnoses of depression, dysthymia and agoraphobia make strong contributions to PTSD; but that combat stress makes the largest contribution even after controlling for the effects of other variables. Psychiatric diagnoses and combat stress appear to be independent in their effects on PTSD.

Variations in living donor graft rates by dialysis clinic: effect on outcome and cost of chronic renal failure therapy

OBJECT

Examination of nephrology practice variations in living donor renal grafts to determine their influence on organ supply, quality, and cost of chronic renal failure therapy.

MATERIALS

Saskatchewan chronic dialysis, cadaveric, and living donor renal grafts in 1983-1994 inclusive.

RESULTS

Saskatchewan has three dialysis (I, II, III) and one transplant clinic. In the period the renal graft incidences/million population by these dialysis clinics by organ source were; Cadaveric: 23.1, 23.2, 21.1 (p = ns). Living: 5.4, 21.7, 8.3 (I or III vs II p < 0.000, I vs III p < 0.061). Total: 28.7, 44.7, 29.4. Living donor series A is 79 grafts in patients under age 60 with primary renal disease. Series B is 20 grafts in patients with secondary renal disease or over age 59. Series A ten-year actuarial patient survival is 92% and B 44%. Series A ten-year actuarial graft survival (including regrafts) is 77% and B 39%. Rehabilitation rate in patients with functioning grafts is 88.5%. Province-wide extension of the Clinic II living-donor graft rate in 1983-1994 would have produced 160 more renal grafts or 59% of those receiving chronic dialysis in 1994. The annual maintenance for a graft with the initial grafting cost taken over five years was $10,825 and the dialysis cost $40,100.

CONCLUSIONS

(1) nephrology practice variations caused a 2.5-4.0-fold difference in living donor renal graft rates, indicating patient education by the attending nephrologist influences the living donor transplantation rate, (2) with such education the combined living donor and the cadaveric organ supply virtually meets graft demand, (3) living donor renal grafts yield a better quantity and quality of life and better cost control than dialysis with their annual cost being one-quarter that for dialysis.

Help-seeking in Vietnam veterans: post-traumatic stress disorder and other predictors

This study investigated factors predicting help-seeking from the Department of Veterans' Affairs (DVA) by Vietnam veterans. Data used were from a national Australian survey of Vietnam veterans' health (n = 641) conducted between July 1990 and April 1993. The survey involved current clinical assessments and retrospective questionnaires, supplemented with health and service records retrieved from the DVA and Army personnel files. Measures included the 1989-90 Australian Bureau of Statistics Health Survey questionnaire, and mental health, sociodemographic and operational deployment history questionnaires. For both current and lifetime diagnoses of post-traumatic stress disorder, a third of the veterans with the disorder had never obtained any health care entitlement from the DVA. Other than physical and mental problems, which accounted for the greatest proportion of the help-seeking odds, significant factors predicting help-seeking included factors such as: predeployment personality, combat exposure, the veterans' own attitudes towards their deployment, experiences during deployment, experiences during repatriation and membership of ex-service organisations. These findings on how post-traumatic stress disorder and other health problems relate to help-seeking patterns could help in developing prevention and care programs for stress disorder.

Surviving the war zone experience: preventing psychiatric casualties

This paper describes a conceptual framework for the development and evaluation of stress-prevention programs for military personnel. In recognition of the diversity of stressors present within a war zone, we propose that an effective prevention program must operate on two levels if it is to deal with the effects of war zone exposure. Prevention programs must target (1) the occupational and/or traumatic stressor(s) within the war zone and (2) the ensuing post-exposure behaviors. A case study is presented to illustrate some of the key prevention issues for military personnel.

The pathogenesis of pulmonary fibrosis: is there a fibrosis gene?

Interstitial fibrosis is seen in the lung in response to a variety of insults, and often appears stereotypical in terms of its clinical and pathological features. However, exposure to a known aetiological factor does not always lead to fibrosis. For example in bleomycin-induced pulmonary fibrosis, a wide variation in response is seen both in humans and in animal models, which is not completely accounted for by known risk factors. These observations and the existence of a number of familial forms of lung fibrosis suggest a genetic predisposition. Current hypotheses concerning the pathogenesis of pulmonary fibrosis propose an initial stage involving the influx of inflammatory cells into the interstitium. These cells, together with activated resident cells are then thought to release polypeptide mediators that stimulate the fibroblast proliferation and matrix protein synthesis typical of these disorders. Genetic influences could have an important role in regulating a number of these events, altering the immunological response to injury or modulating collagen metabolism in the lung. However, despite recent advances in molecular genetic techniques, there have been few human studies to date. Most have concentrated on genetic loci with a high degree of polymorphism such as the human leucocyte antigen (HLA) system and yield conflicting results. Others offer tantalising but as yet, incomplete insights into the mechanisms involved. Defining the genetic abnormalities underlying both the familial forms of pulmonary fibrosis and the variations seen in response to lung injury should enhance our understanding of the pathogenic processes and help to focus research in this area.

Australian Vietnam veterans: factors contributing to psychosocial problems

OBJECTIVE

The objective of the present paper is to present comprehensive models of the current psychosocial morbidity of Australian Vietnam veterans. Seldom has research in this area attempted to 'untangle' direct and indirect influences on current functioning via possible pre-army, Vietnam and homecoming pathways.

METHOD

The Australian Vietnam Veterans' Health Study gathered data on a sample of 641 veterans throughout Australia drawn randomly from army Vietnam tour lists of the era. The data arose from interview and army records of the era, and fall into four temporal categories: pre-army, Vietnam service, homecoming after Vietnam, and current state. Path analysis models of the veterans' current psychological morbidities and social wellbeing are used to identify direct aetiological influences of earlier era constructs on current state, free of confounding by indirect (often selection) effects.

RESULTS

Our results indicate that psychological morbidity (particularly posttraumatic stress disorder) is largely influenced by combat and poor homecoming experiences, although pre-military characteristics do play some direct roles in symptomatology. Social dysfunction measures show smaller effects of the Vietnam War, which may be accounted for by an indirect association with Vietnam-related psychological morbidity. Some social measures show evidence of compensatory influences of combat, high combat leading to social dysfunction because of morbidity, but simultaneously being associated with healthier social disposition (possibly because of increased exservice activity).

CONCLUSIONS

For Australian Vietnam veterans, combat-related and homecoming effects persist on a range of psychosocial endpoints 20-30 years after exposure. These effects are not explicable in terms of veterans pre-Vietnam characteristics.

Interviewer effects on epidemiologic diagnoses of posttraumatic stress disorder

In an epidemiologic study of 641 interviewed subjects in the Australian Vietnam Veterans Health Study, three diagnoses of Vietnam combat-related posttraumatic stress disorder (PTSD) were obtained: lifetime prevalence using a variant of the Diagnostic Interview Schedule and lifetime and current (1-month) PTSD prevalence using the Standardized Clincical Interview for the Diagnostic and Statistical Manual of Mental Disorders, Third Revision. Prevalence estimates using the Standardized Clinical Interview varied according to interviewer characteristics (female vs. male, clinician vs. nonclinician) but not for the Diagnostic Interview Schedule. The authors use a simple variant of logistic regression to distill estimates of two informative parameters characterizing interviewers' judgments: severity threshold (related to the individual interviewer's criterion of "caseness") and reliability (related to degree of classification error of the individual interviewers). Examination of these estimates shows that female clinicians adopted lower severity thresholds for diagnosis of PTSD than other interviewers and hence had higher prevalence estimates while being relatively reliable in their judgments. Examination also shows that nonclinician interviewers can perform at least as reliably as clinicians. The Diagnostic Interview Schedule measure of PTSD was not moderated by these interviewer aspects. This use of threshold and reliability parameters is offered for routine use in epidemiologic field studies to examine potential interviewer effects.

The Australian Vietnam Veterans Health Study: III. psychological health of Australian Vietnam veterans and its relationship to combat

BACKGROUND

Self-reported psychiatric status of Australian Vietnam war veterans was determined 20-25 years after the war and its relation to combat was investigated.

METHOD

A simple random sample of Australian Army Vietnam veterans was interviewed nationally using standardized interviews and self-completion tests to assess the prevalence of lifetime and current psychiatric illness and its relationship to combat. Army records were used to extract data on the cohort for use in regression-based adjustment for non-response.

RESULTS

The conditions mainly affecting the Australian veterans were alcohol abuse or dependence, post-traumatic stress disorder, somatization disorder were significantly related to combat exposure but not with posting to a combat unit. Less than half of the current one-month diagnoses were related to combat, possibly because of low power conferred by the relative rarity of these conditions.

CONCLUSIONS

The results confirm a range of psychological problems in former warriors may linger 20 or more years from their war exposure and may be directly affected by exposure to war trauma.

The Australian Vietnam Veterans Health Study: II. self-reported health of veterans compared with the Australian population

BACKGROUND

Self-reported physical health status of Australian Vietnam veterans was determined 20-25 years after the war and its relation to combat was investigated.

METHOD

An epidemiological cohort study of a simple random sample of Army veterans posted to Vietnam between 1964 and 1972 was conducted with personal interviews using the Australian Bureau of Statistics Health Interview Survey questionnaire to compare veterans with the Australian population and a 21-item combat exposure index used to measure the relationship of combat to physical health.

RESULTS

Veterans reported greater health service usage and more recent health actions than population expectations. They also reported excess health problems in almost all recent illness disease categories except endocrine conditions and cardiovascular conditions; only 6 of 37 chronic disease groups were not elevated compared to the population. Adjustment for non-response changed estimates only slightly. Combat exposure was significantly related to reports of recent and chronic mental disorders, recent hernia and chronic ulcer, recent eczema and chronic rash, deafness, chronic infective and parasitic disease, chronic back disorders and symptoms, signs and ill-defined conditions.

CONCLUSION

Combat exposure may have significantly increased reports of only some health problems. A general position to complain as a result of psychological conditions due to combat is not consistent with the lack of relationship between combat and reports of physical conditions.

The Australian Vietnam Veterans Health Study: I. study design and response bias

BACKGROUND

The Australian Vietnam Veterans Health Study was set up to examine the post-war health of former soldiers 20 or more years after service and to examine the relation of combat exposure to physical and mental health.

METHOD

A prospective cohort study of a simple random sample of 1000 male Australian Army Vietnam veterans used information gathered from Army records, from personnel interview and questionnaires. Military records were used to examine response bias by determining the differences between 641 interviewed veterans, 50 known deceased veterans and 309 non-respondents (including 48 refusers and 213 non-traceable).

RESULTS

Differences were evident between respondents and non-respondents, with logistic regression modelling pointing to pre-enlistment employment, antisocial behaviour, intelligence and post-Vietnam AWOL (absent without leave) as the most important discriminants with non-respondents performing worse. Compared to respondents, deceased left school earlier, had higher rank in Vietnam and at discharge, had a higher overall number of charges but not a higher rate overall, and were less likely to have gone AWOL. Deceased also received more casualty reports than respondents and non-respondents, were better behaved during service, and were better emotionally adjusted than non-respondents. Respondents compared with the Australian population had equivalent or better current socioeconomic status.

CONCLUSION

There seems little bias due to non-response, but deceased tend to come from and older cohort than in the other two groups.