Exercises versus arthroscopic decompression in patients with subacromial impingement: a randomised, controlled study in 90 cases with a one year follow up

OBJECTIVES

To compare the effect of graded physiotherapeutic training of the rotator cuff versus arthroscopic subacromial decompression in patients with subacromial impingement.

METHODS

Randomised controlled trial with 12 months' follow up in a hospital setting. Ninety consecutive patients aged 18 to 55 years were enrolled. Symptom duration was between six months and three years. All fulfilled a set of diagnostic criteria for rotator cuff disease, including a positive impingement sign. Patients were randomised either to arthroscopic subacromial decompression, or to physiotherapy with exercises aiming at strengthening the stabilisers and decompressors of the shoulder. Outcome was shoulder function as measured by the Constant score and a pain and dysfunction score. "Intention to treat" analysis was used, with comparison of means and control of confounding variables by general equation estimation analysis.

RESULTS

Of 90 patients enrolled, 84 completed follow up (41 in the surgery group, 43 in the training group). The mean Constant score at baseline was 34.8 in the training group and 33.7 in the surgery group. After 12 months the mean scores improved to 57.0 and 52.7, respectively, the difference being non-significant. No group differences in mean pain and dysfunction score improvement were found.

CONCLUSIONS

Surgical treatment of rotator cuff syndrome with subacromial impingement was not superior to physiotherapy with training. Further studies are needed to qualify treatment choice decisions, and it is recommended that samples are stratified according to disability level.

The Mouse Genome Database (MGD): from genes to mice--a community resource for mouse biology

The Mouse Genome Database (MGD) forms the core of the Mouse Genome Informatics (MGI) system (http://www.informatics.jax.org), a model organism database resource for the laboratory mouse. MGD provides essential integration of experimental knowledge for the mouse system with information annotated from both literature and online sources. MGD curates and presents consensus and experimental data representations of genotype (sequence) through phenotype information, including highly detailed reports about genes and gene products. Primary foci of integration are through representations of relationships among genes, sequences and phenotypes. MGD collaborates with other bioinformatics groups to curate a definitive set of information about the laboratory mouse and to build and implement the data and semantic standards that are essential for comparative genome analysis. Recent improvements in MGD discussed here include the enhancement of phenotype resources, the re-development of the International Mouse Strain Resource, IMSR, the update of mammalian orthology datasets and the electronic publication of classic books in mouse genetics.

Understanding work related musculoskeletal pain: does repetitive work cause stress symptoms?

BACKGROUND

Pain in the neck and upper extremity is reported with high frequency in repetitive work. Mechanical overload of soft tissues seems a plausible mechanism, but psychological factors have received considerable attention during the past decade. If psychological factors are important for development of regional pain in repetitive work, stress symptoms would likely be on the causal path.

AIMS

To examine whether objective measures of repetitive monotonous work are related to occurrence and development of stress symptoms.

METHODS

In 1994-95, 2033 unskilled workers with continuous repetitive work and 813 workers with varied work were enrolled. Measures of repetitiveness and force requirements were quantified using video observations to obtain individual exposure estimates. Stress symptoms were recorded at baseline and after approximately one, two, and three years by the Setterlind Stress Profile Inventory.

RESULTS

Repetitive work, task cycle time, and quantified measures of repetitive upper extremity movements including force requirements were not related to occurrence of stress symptoms at baseline or development of stress symptoms during three years of follow up.

CONCLUSIONS

The findings do not indicate that repetitive work is associated with stress symptoms, but small effects cannot be ruled out. Thus the results question the importance of mental stress mechanisms in the causation of regional pain related to repetitive work. However, the findings should be interpreted with caution because the stress inventory has not been validated against a gold standard.

Work related physical activity and risk of a hospital discharge diagnosis of atrial fibrillation or flutter: the Danish Diet, Cancer, and Health Study

BACKGROUND AND AIMS

Excessive sporting activities have been associated with risk of atrial fibrillation. To study if work related physical activity also confers risk of atrial fibrillation or flutter, the association between work related physical strain and the risk of a hospital discharge diagnosis (inpatient as well as outpatient) of atrial fibrillation or flutter was examined.

METHODS

A population based prospective cohort study was conducted from December 1993 to December 2001 among 19 593 men and 18,807 women with a mean age at baseline of 56 years (range 50-65 years) in the Danish Diet, Cancer, and Health Study. The physical strain during working hours was categorised as sedentary, light, or heavy, and analysed using proportional hazard models. Subjects were followed up in the Danish National Registry of Patients and in the Danish Civil Registration System.

RESULTS

During follow up (mean 5.7 years) a hospital discharge diagnosis of atrial fibrillation or flutter occurred in 305 men and 113 women. When using the risk of atrial fibrillation or flutter associated with sedentary work at a sitting position as a reference, no excess risk (unadjusted as well as adjusted) was found of atrial fibrillation or flutter associated with sedentary work in a standing position, light workload, or heavy workload in men or women.

CONCLUSION

No evidence was found of an association between physical activities during working hours and risk of a hospital discharge diagnosis of atrial fibrillation or flutter for men and women in the age group of 50-65 years.

Impaired left ventricular diastolic function during isometric exercise in asymptomatic patients with hyperlipidaemia

BACKGROUND

Left ventricular (LV) diastolic dysfunction is an early sign, and may be more sensitive indicator, of ischaemic heart disease (IHD) than systolic dysfunction.

METHODS

LV diastolic function was assessed during isometric exercise (IME) in 37 consecutive normotensive hyperlipidaemics (LIP), without cardiac history or symptoms. Each patient underwent a stress ECG test and 2-D echo and Doppler cardiography. During the latter, transmitral flow at rest and at peak standardised IME using handgrip was studied. From the tracings, the E/A (peak velocity of the early/atrial components), the contribution of atrial systole to LV filling (ACF), the deceleration time (DT) of the E wave and the isovolumic relaxation time (IVRT) were calculated. Results were compared to 37 age-matched normal healthy volunteers (NOR).

RESULTS

Resting E/A was not different between NOR and the LIP. A significant reduction in E/A with IME was observed in LIP but not in NOR. Impaired LV filling (shown by E/A<1) was demonstrated in five patients (13%) at rest and in 20 patients (54%) at peak IME. All NOR had E/A>1 suggesting normal LV filling. Fifteen of the 30 patients with negative stress ECG test demonstrated LV diastolic dysfunction. ACF was higher in LIP than NOR and increased significantly (P<0.005) by 23% during IME. DT and IVRT in LIP were not different from NOR. In neither NOR nor LIP, were the LV diastolic functional parameters related to gender, smoking habit or levels of total cholesterol, LDL- or HDL-cholesterol or triglycerides.

CONCLUSION

The prevalence of LV diastolic dysfunction in asymptomatic patients with hyperlipidaemia despite a negative stress ECG test may be evidence of early underlying pre-clinical myocardial ischaemia.

The prototypic antidepressant drug, imipramine, but not Hypericum perforatum (St. John's Wort), reduces HPA-axis function in the rat

Dysregulation in corticotropin-releasing hormone (CRH) secretion in the hypothalamus-pituitary-adrenal (HPA) axis may be involved in the etiology of major depressive disorder (MDD). Chronic therapy with standard antidepressant drugs, such as imipramine, can downregulate HPA axis function, indicating that the HPA axis may be an important target for antidepressant action. We tested several doses of a standardized commercial preparation of Hypericum perforatum plant extract (popularly known as St. John's Wort), a medicinal herb used for treating mild depressive symptoms, to determine whether it also modulated HPA axis function. Chronic imipramine treatment (daily injections for 8 weeks) of male Sprague-Dawley rats significantly downregulated circulating plasma levels of adrenocorticotropic hormone (ACTH) and corticosterone compared to animals treated with saline. However, chronic St. John's Wort treatment (daily gavage for 8 weeks) had no effect on plasma ACTH or corticosterone, even at the highest doses tested. Our results confirm previous findings that imipramine may have significant peripheral HPA axis-mediated effects. However, our data does not support any role for H. perforatum in modulation of HPA axis function, suggesting that alternative pathways may be involved in mediating its antidepressant effects.

Prognosis of shoulder tendonitis in repetitive work: a follow up study in a cohort of Danish industrial and service workers

BACKGROUND

The physical and psychosocial work environment is expected to modify recovery from shoulder disorders, but knowledge is limited.

METHODS

In a follow up study of musculoskeletal disorders in industrial and service workers, 113 employees were identified with a history of shoulder pain combined with clinical signs of shoulder tendonitis. The workers had yearly re-examinations up to three times. Quantitative estimates of duration, repetitiveness, and forcefulness of current tasks were obtained from video recordings. Perception of job demands, decision latitude, and social support was recorded by a job content questionnaire. Recovery of shoulder tendonitis was analysed by Kaplan-Meier survival technique and by logistic regression on exposure variables and individual characteristics in models, allowing for time varying exposures.

RESULTS

Some 50% of workers recovered within 10 months (95% CI 6 to 14 months). Higher age was strongly related to slow recovery, while physical job exposures were not. Perception of demands, control, and social support at the time when the shoulder disorder was diagnosed, were associated with delayed recovery, but these psychosocial factors did not predict slow recovery in incident cases identified during follow up.

CONCLUSION

The median duration of shoulder tendonitis in a cross sectional sample of industrial and service workers was in the order of 10 months. This estimate is most likely biased towards too high a value. Recovery was strongly reduced in higher age. Physical workplace exposures and perceived psychosocial job characteristics during the period preceding diagnosis seem not to be important prognostic factors.

Risk factors in the onset of neck/shoulder pain in a prospective study of workers in industrial and service companies

AIMS

To quantify the relative contribution of work related physical factors, psychosocial workplace factors, and individual factors and aspects of somatisation to the onset of neck/shoulder pain.

METHODS

Four year prospective cohort study of workers from industrial and service companies in Denmark. Participants were 3123 workers, previously enrolled in a cross sectional study, where objective measurement of physical workplace factors was used. Eligible participants were followed on three subsequent occasions with approximately one year intervals. Outcomes of interest were: new onset of neck/shoulder pain (symptom cases); and neck/shoulder pain with pressure tenderness in the muscles of the neck/shoulder region (clinical cases).

RESULTS

During follow up, 636 (14.1%) participants reported neck/shoulder pain of new onset; among these, 82 (1.7%) also had clinical signs of substantial muscle tenderness. High shoulder repetition was related to being a future symptom case, and a future clinical case. Repetition was strongly intercorrelated with other physical measures. High job demands were associated with future status as a symptom case, and as a clinical case. A high level of distress predicted subsequent neck/shoulder pain, and neck/shoulder pain with pressure tenderness.

CONCLUSIONS

High levels of distress, and physical and psychosocial workplace factors are predictors of onset of pain in the neck and/or shoulders, particularly pain with pressure tenderness in the muscles.

Polyarteritis nodosa in a cynomolgus macaque (Macaca fascicularis)

Polyarteritis nodosa (PAN) is an idiopathic necrotizing vasculitis affecting small- to medium-sized arteries. The disease is well recognized in humans, and PAN-like syndromes have been described in a number of other species. This report describes a case of PAN in a 6-year-old male cynomolgus macaque. The animal had necrotizing arteritis affecting vessels in the kidney, small intestine, colon, heart, spleen, mesentery, urinary bladder, and pancreas. The lesions were segmental in distribution and of varying severity and stage of development. A transmural mixed inflammatory cell infiltrate was present, often accompanied by fibrinoid necrosis of the tunica media and loss of the internal elastic lamina. Immunohistochemical staining showed that many of the infiltrating cells were T lymphocytes and histiocytes, suggesting a cell-mediated component to the pathogenesis.

Increasing false recognition rates with confirmatory feedback: a phenomenological analysis

During a simulated witness interrogation, participants were encouraged to confabulate an account consistent with false information concerning a videotaped event. The interviewer verbally affirmed some false responses. Previous research has shown that, a week later, participants often recognize confabulated events that were affirmed by the experimenter as being from the video. What is unclear is whether confirmatory feedback encouraged a change in the mental representation of the confabulated events to fit the original event or confirmation might have merely encouraged a change in beliefs about the event. To further understand the mechanisms that underlie the confirmatory feedback effect, participants were asked to judge the phenomenological experience associated with false recognition.

Why misinformation is more likely to be recognised over time: A source monitoring account

Although memory for actual events tends to be forgotten over time, memory for misinformation tends to be retrieved at a stable rate over long delays or at a rate greater than that found immediately after encoding. To examine whether source monitoring errors contribute to this phenomenon, two experiments investigated subjects' memory for the source of misinformation at different retention intervals. Subjects viewed a slide presentation, read a narrative containing misinformation, and, either 10 minutes or 1 week later, completed a recognition test about details seen in the slides and about the source of these details. After the longer retention interval in both experiments, participants were more likely to agree that they had seen misleading information and were also more likely to incorrectly associate the misinformation with the slide event. Theoretical implications of these findings are considered.

IL-1 receptor type I gene expression in the amygdala of inflammatory susceptible Lewis and inflammatory resistant Fischer rats

Lewis (LEW/N) and Fischer (F344/N) rats have different responses to inflammatory and behavioral stressors due to differences in hypothalamus-pituitary-adrenal (HPA) axis function. For example, LEW/N rats are more sensitive to restraint, inflammation and experimentally induced autoimmunity due to decreased HPA activity. The HPA axis response to peripheral inflammation is mediated, at least in part, by IL-1beta and its receptor, IL-1 type I (IL-1RI). Here, we studied the distribution of IL-1RI mRNA in the brains of LEW/N and F344/N rats, and demonstrated that IL-1RI mRNA expression has significantly increased in the basolateral nucleus (BLA) of the amygdala of LEW/N rats. These findings suggest that strain-specific HPA axis responses may be mediated by extrahypothalamic pathways.

A novel inhibitor of tumor necrosis factor-alpha converting enzyme ameliorates polycystic kidney disease

BACKGROUND

Transforming growth factor-alpha (TGF-alpha) expression is abnormal in polycystic kidney disease. We previously demonstrated that blockade of the epidermal growth factor receptor (EGFR), the receptor for TGF-alpha, significantly slowed disease progression in the bpk murine model of autosomal-recessive kidney disease (ARPKD). In the present study, kidney TGF-alpha expression in this model is characterized, and the therapeutic potential of inhibiting TGF-alpha in ARPKD is examined using a novel inhibitor of tumor necrosis factor-alpha converting enzyme (TACE), the metalloproteinase that cleaves membrane-bound TGF-alpha to release the secreted ligand.

METHODS

Immunohistochemistry (IH) and Western analysis were performed on kidneys from cystic bpk mice and noncystic littermates at postnatal days 7, 14, and 21. Bpk mice and normal controls were treated with WTACE2, a competitive inhibitor of TACE, from day 7 until day 21, and the effects on kidney histology and renal function were assessed.

RESULTS

Increased TGF-alpha expression by IH was demonstrated in the proximal tubules (PT) at postnatal day 7 and collecting tubules (CT) by day 21. A parallel increase in kidney TGF-alpha expression was demonstrated by Western analysis. Treatment of cystic bpk mice with WTACE2 resulted in a 43% reduction in kidney weight to body weight ratio (11.2 vs. 19.7%), improved cystic index (3.2 vs. 4.8), reduced cystic CT to PT ratio (1.2 vs. 8), and a greater than 30% reduction in BUN and serum creatinine.

CONCLUSIONS

These findings support the pathophysiological role of the TGF-alpha/EGFR axis in murine ARPKD and demonstrate that inhibition of TGF-alpha secretion has therapeutic potential in PKD.

A new antiestrogen, 2-(4-hydroxy-phenyl)-3-methyl-1-[4-(2-piperidin-1-yl-ethoxy)-benzyl]-1H-indol-5-ol hydrochloride (ERA-923), inhibits the growth of tamoxifen-sensitive and -resistant tumors and is devoid of uterotropic effects in mice and rats

PURPOSE

Tamoxifen is an antiestrogen used in women who have estrogen receptor (ER)-alpha-positive breast cancer. Unfortunately, resistance to tamoxifen is common in women with metastatic disease and side effects, including increased risk of endometrial cancer, exist. Here we describe the activity of a new selective ER modulator, ERA-923, in preclinical models focused on these limitations.

EXPERIMENTAL DESIGN

The ability of ERA-923, 4-OH tamoxifen, or raloxifene to inhibit estrogen-stimulated growth was evaluated in cell-based and xenograft assays with tumor cells that are sensitive or resistant to tamoxifen. Uterine effects of selective ER modulators were compared in rodents.

RESULTS

ERA-923 potently inhibits estrogen binding to ER-alpha (IC(50), 14 nM). In ER-alpha-positive human MCF-7 breast carcinoma cells, ERA-923 inhibits estrogen-stimulated growth (IC(50), 0.2 nM) associated with cytostasis. In vitro, a MCF-7 variant with inherent resistance to tamoxifen (10-fold) or 4-OH tamoxifen (>1000-fold) retains complete sensitivity to ERA-923. Partial sensitivity to ERA-923 exists in MCF-7 variants that have acquired profound tamoxifen resistance. In tumor-bearing animals, ERA-923 (10 mg/kg/day given p.o.) inhibits 17beta-estradiol-stimulated growth in human tumors derived from MCF-7, EnCa-101 endometrial, or BG-1 ovarian carcinoma cells, including a MCF-7-variant that is inherently resistant to tamoxifen. Raloxifene is inactive in the MCF-7 xenograft model. Unlike tamoxifen, droloxifene, or raloxifene, ERA-923 is not uterotropic in immature rats or ovariectomized mice. Consistent with this, tamoxifen, but not ERA-923, stimulates the growth of EnCa-101 tumors.

CONCLUSIONS

In preclinical models, ERA-923 has an improved efficacy and safety compared with tamoxifen. Clinical trials with ERA-923 are in progress.

mTOR, a novel target in breast cancer: the effect of CCI-779, an mTOR inhibitor, in preclinical models of breast cancer

The mammalian target of rapamycin (mTOR) is a central regulator of G1 cell cycle protein synthesis that precedes commitment to normal cellular replication. We have studied the effect of cell cycle inhibitor-779 (CCI-779), a rapamycin ester that inhibits mTOR function, on the proliferation of a panel of breast cancer cell lines. Six of eight lines studied were sensitive (IC(50)< or = 50 nM) and two lines were resistant (IC(50)>1.0 microM) to CCI-779. Sensitive lines were estrogen dependent (MCF-7, BT-474, T-47D), or lacked expression of the tumor suppressor PTEN (MDA-MB-468, BT-549), and/or overexpressed the Her-2/neu oncogene (SKBR-3, BT-474). Resistant lines (MDA-MB-435, MDA-MB-231) shared none of these properties. CCI-779 (50 nM) inhibited mTOR function in both a sensitive and a resistant line. In nu/nu mouse xenografts, CCI-779 inhibited growth of MDA-MB-468 (sensitive) but not MDA-MB-435 resistant tumors. Treatment of sensitive lines with CCI-779 resulted in a decrease in D-type cyclin and c-myc levels and an increase in p27(kip-1) levels. There was good correlation between activation of the Akt pathway and sensitivity to CCI-779. Amplification of mTOR-regulated p70S6 kinase, which is downstream of Akt, may also have conferred CCI-779 sensitivity to MCF-7 cells. Taken together, the data suggest that mTOR may be a good target for breast cancer therapy, especially in tumors with Akt activation resulting from either growth factor dependency or loss of PTEN function.

Enhanced sensitivity of PTEN-deficient tumors to inhibition of FRAP/mTOR

Recent evidence places the FRAP/mTOR kinase downstream of the phosphatidyl inositol 3-kinase/Akt-signaling pathway, which is up-regulated in multiple cancers because of loss of the PTEN tumor suppressor gene. We performed biological and biochemical studies to determine whether PTEN-deficient cancer cells are sensitive to pharmacologic inhibition of FRAP/mTOR by using the rapamycin derivative CCI-779. In vitro and in vivo studies of isogenic PTEN(+/+) and PTEN(-/-) mouse cells as well as human cancer cells with defined PTEN status showed that the growth of PTEN null cells was blocked preferentially by pharmacologic FRAP/mTOR inhibition. Enhanced tumor growth caused by constitutive activation of Akt in PTEN(+/+) cells also was reversed by CCI-779 treatment, indicating that FRAP/mTOR functions downstream of Akt in tumorigenesis. Loss of PTEN correlated with increased S6 kinase activity and phosphorylation of ribosomal S6 protein, providing evidence for activation of the FRAP/mTOR pathway in these cells. Differential sensitivity to CCI-779 was not explained by differences in biochemical blockade of the FRAP/mTOR pathway, because S6 phosphorylation was inhibited in sensitive and resistant cell lines. These results provide rationale for testing FRAP/mTOR inhibitors in PTEN null human cancers.

An inhibitor of mTOR reduces neoplasia and normalizes p70/S6 kinase activity in Pten+/- mice

PTEN phosphatase acts as a tumor suppressor by negatively regulating the phosphoinositide 3-kinase (PI3K) signaling pathway. It is unclear which downstream components of this pathway are necessary for oncogenic transformation. In this report we show that transformed cells of PTEN(+/-) mice have elevated levels of phosphorylated Akt and activated p70/S6 kinase associated with an increase in proliferation. Pharmacological inactivation of mTOR/RAFT/FRAP reduced neoplastic proliferation, tumor size, and p70/S6 kinase activity, but did not affect the status of Akt. These data suggest that p70/S6K and possibly other targets of mTOR contribute significantly to tumor development and that inhibition of these proteins may be therapeutic for cancer patients with deranged PI3K signaling.

Enhanced detection of mutations in BRCA1 exon 11 using restriction endonuclease fingerprinting-single-strand conformation polymorphism

A novel approach to mutation screening in the large exon 11 (comprising 3427 bp) of the human BRCA1 gene is presented. Restriction endonuclease fingerprinting single-strand conformation polymorphism (REF-SSCP) is based on repeated detection of DNA sequence variants in different restriction endonuclease fragments, and we evaluated the method using blood samples from 25 Norwegian patients with hereditary breast/ovarian cancer. We compared REF-SSCP to constant denaturant gel electrophoresis (CDGE) and to the protein truncation test (PTT). REF-SSCP detected 12 different DNA variants. Four of these were not detected by CDGE, and only one variant detected by CDGE was missed by REF-SSCP. PTT detected 4 of these 13 variants. REF-SSCP was subsequently applied to a second patient series (Swedish, n=20). A total of 14 different DNA variants were detected by REF-SSCP, 6 of which were truncating mutations (PTT detected only 4). Nonsense and frameshift mutations that are putative breast/ovarian cancer mutations, were detected in 7 of the 25 Norwegian and 9 of the 20 Swedish patients.

Physical exposure assessment in monotonous repetitive work--the PRIM study

OBJECTIVES

A program called the Project on Research and Intervention in Monotonous Work (PRIM) was initiated in 1994 as a prospective cohort study of work-related musculoskeletal disorders. The group-based exposure assessment strategy, focusing on task-related exposure and used to obtain baseline measures of physical exposures, is reported in this paper.

METHODS

Monotonous, repetitive worktasks were evaluated at 19 factories. Tasks with an estimated similarity in physical exposure were aggregated before 103 exposure groups were formed. Subjects from the exposure groups were randomly sampled for measurements, and task-related exposure levels were quantified by 43 single exposure items using a real-time video-based observation method that allowed computerized estimates of repetitiveness, body postures, force, and velocity. In combination with questionnaire-based data on task distribution, the duration of exposure was calculated at the individual level.

RESULTS

The video-based observational method and the large number of exposure variables enabled the establishment of detailed quantitative exposure profiles in 103 task-based exposure groups. However, methodological problems associated with the use of grouped exposure assessment were revealed. Despite efforts to optimize group homogeneity, the within-group variance was larger than the between-group variance for several shoulder postural variables.

CONCLUSIONS

A task-based exposure-assessment strategy can be successful in solving some of the main problems associated with the assessment of physical workplace exposures. The large within-group variance in exposure to nonneutral shoulder postures may eventually require individual assessment or the inclusion of groups with maximal contrast in exposure or both.

Apoptotic colonic disease: a new entity in a primate

A Macaca fascicularis died following chronic, intractable diarrheas. At autopsy, the entire colon was macroscopically red and swollen. At histology, the most conspicuous histologic finding was a marked accumulation of intraepithelial apoptotic granules in the lower one third of the epithelium of the colonic crypts. The cells in those crypts showed various degrees of swelling or necrobiosis. Since no other explanation was found at autopsy, it was concluded that the marked apoptosis with marked epithelial cell destruction was the cause of the colonic disease which apparently resulted in untreatable protracted diarrheas in this animal. The term apoptotic colonic disease is proposed for this previously unreported condition.