Fibroblastic Subtype has a Favourable Prognosis in Appendicular Osteosarcoma of Dogs.

Osteosarcoma (OS) is an aggressive malignant bone neoplasm that occurs mostly in the appendicular skeleton of dogs and people. OS is classified based on the presence of malignant stroma and the formation of extracellular matrix into osteoblastic, chondroblastic and fibroblastic forms. This study investigated the correlation between the three histological subtypes of canine OS and clinical outcome. Additionally, we examined whether there was any difference in the immunolabelling of desmin, S100 and neuron-specific enolase (NSE) between the three histological subtypes. Formalin-fixed and paraffin wax-embedded tissues from 87 dogs with primary OS were available for this study. The survival times were correlated with appendicular OS subtypes in dogs that were treated surgically, received adjuvant chemotherapy and had no pulmonary metastasis at the time of diagnosis. Dogs with an appendicular fibroblastic OS had significantly prolonged mean average survival times (546 ± 105 days) in comparison with dogs having appendicular osteoblastic (257 ± 48 days) or appendicular chondroblastic (170 ± 28 days) OS (P = 0.003, Log Rank). The results also revealed that the appendicular chondroblastic subtype is a significant indicator for poor prognosis in dogs compared with the fibroblastic or osteoblastic subtypes (P = 0.006, Cox regression). Moreover, the findings indicated that there was no significant correlation between the localization of desmin, NSE or S100 and histological subtypes. Importantly, dogs with appendicular fibroblastic OS were found to have a better prognosis when compared with dogs with other subtypes. This may suggest that histological subtypes of appendicular OS have diverse behaviour and could be used to categorize patients for risk-based assessment.

Immunohistochemical Validation of Spontaneously Arising Canine Osteosarcoma as a Model for Human Osteosarcoma.

Osteosarcoma (OS) originates from bone-forming mesenchymal cells and represents one of the primary bone tumours. It is the most common primary bone tumour in dogs and man. The characterization of an appropriate natural disease animal model to study human OS is essential to elucidate the pathogenesis of the disease. This study aimed to validate canine OS as a model for the human disease by evaluating immunohistochemically the expression of markers known to be important in human OS. The immunohistochemical panel included vimentin, alkaline phosphatase (ALP), desmin, S100, neuron-specific enolase (NSE), runt-related transcription factor 2 (Runx2) and bone morphogenetic protein 4 (BMP4). Immunohistochemistry was conducted on formalin-fixed, paraffin wax-embedded tissue sections from 59 dogs with confirmed primary OS. Vimentin, ALP, Runx2 and BMP4 were highly expressed by all tumours, while desmin, S100 and NSE were expressed variably. The findings were similar to those described previously for human OS and suggest that canine OS may represent a useful model for the study of the human disease.

Canine Mixed Mammary Tumour as a Model for Human Breast Cancer with Osseous Metaplasia.

Canine mixed mammary tumours (CMMTs) and human metaplastic breast carcinomas (HMBCs) share several histopathological features and risk factors. In both species, these tumours display epithelial and stromal components. HMBCs are rare malignant tumours, but CMMTs are one of the most common mammary tumours in dogs and are more often benign than malignant. In this study, benign (n = 88) and malignant (n = 13) CMMTs were characterized using specific antibodies against oestrogen receptor, progesterone receptor, human epidermal growth factor receptor 2, cytokeratin 5/6, cytokeratin AE1/AE3, vimentin, Ki67, E-cadherin and p63. Cartilage and bone matrices associated with benign and malignant CMMTs were characterized using specific antibodies against BMP4, Runx2, Sox9 and osteopontin. The current study suggested that CMMTs are of epithelial origin, but display a myoepithelial-like differentiation. The findings suggest key roles for Sox9, Runx2 and BMP4 in chondrogenesis and bone formation in CMMTs. The high expression of osteopontin in CMMTs appears to be unrelated to tumour malignancy.

Knockdown of PTHR1 in osteosarcoma cells decreases invasion and growth and increases tumor differentiation in vivo.

Osteosarcoma (OS) is the most common cancer of bone. Parathyroid hormone (PTH) regulates calcium homeostasis and bone development, while the paracrine/autocrine PTH-related protein (PTHrP) has central roles in endochondral bone formation and bone remodeling. Using a murine OS model, we found that OS cells express PTHrP and the common PTH/PTHrP receptor (PTHR1). To investigate the role of PTHR1 signaling in OS cell behavior, we used shRNA to reduce PTHR1 expression. This only mildly inhibited proliferation in vitro, but markedly reduced invasion through collagen and reduced expression of RANK ligand (RANKL). Administration of PTH(1-34) did not stimulate OS proliferation in vivo but, strikingly, PTHR1 knockdown resulted in a profound growth inhibition and increased differentiation/mineralization of the tumors. Treatment with neutralizing antibody to PTHrP did not recapitulate the knockdown of PTHR1. Consistent with this lack of activity, PTHrP was predominantly intracellular in OS cells. Knockdown of PTHR1 resulted in increased expression of late osteoblast differentiation genes and upregulation of Wnt antagonists. RANKL production was reduced in knockdown tumors, providing for reduced homotypic signaling through the receptor, RANK. Loss of PTHR1 resulted in the coordinated loss of gene signatures associated with the polycomb repressive complex 2 (PRC2). Using Ezh2 inhibitors, we demonstrate that the increased expression of osteoblast maturation markers is in part mediated by the loss of PRC2 activity. Collectively these results demonstrate that PTHR1 signaling is important in maintaining OS proliferation and undifferentiated state. This is in part mediated by intracellular PTHrP and through regulation of the OS epigenome.

Lacrimal drainage obstruction and dacryocystorhinostomy in children.

PURPOSE: To determine the outcome of dacryocystorhinostomy (DCR) for nasolacrimal duct obstruction (NLDO) in children. METHODS: A review of medical records of 104 cases (82 patients) of paediatric DCR who underwent DCR at the Sydney Eye Hospital from 1995 to 2004. The main outcome measures included post-operative symptomatic relief of presenting symptoms, complications, subjective visibility of any scar, and general satisfaction. Statistical methods included chi(2) tests, and Student's t-tests for the comparison of variables among groups. RESULTS: Ninety-four external, 10 endoscopic primary procedures, and five revision procedures were included. Fifty-six of the cases were primary NLDO, and 48 were secondary NLDO. The mean follow-up was 1.44 years. Average age at surgery was 6.6+/-4.2 years (mean+/-SD). Ninety-one eyes needed DCR for the involvement of the lower lacrimal outflow system, and 13 eyes were NLDO associated with congenital punctual/canalicular dysgenesis.Most of the complications of external DCR were related to Jones tube placement. Five cases (4.8%) needed DCR revision. There was a significantly higher incidence of revision surgery in the non-stented group (P<0.01), and the Jones tube group (P<0.001) as compared with the silicone intubation stent group. CONCLUSIONS: External DCRs have acceptable long-term clinical and cosmetic results, and low post-operative complication rate. Cases with punctal stenosis or those requiring Jones tube insertion are associated with a higher complication rate. Silicone intubation is associated with a lower need for operative revision.

Recapitulation of the parathyroid hormone-related peptide-Indian hedgehog pathway in the regenerating deer antler.

Parathyroid hormone (PTH)-related peptide (PTHrP) and the PTH/PTHrP receptor (PPR) play an essential role in controlling growth plate development. The aim of the present study was to use the deer antler as a model to determine whether PTHrP and PPR may also have a function in regulating cartilage and bone regeneration in an adult mammal. Antlers are the only mammalian appendages that are able to undergo repeated cycles of regeneration, and their growth from a blastema involves a modified endochondral process. Immunohistochemistry was used to establish sites of localization of PTHrP and PPR in antlers at different stages of development. The pattern of Indian Hedgehog (IHH) and transforming growth factor-beta1 (TGF beta1) distribution was also investigated, because PTHrP expression in the developing limb is regulated by IHH and during embryonic growth plate formation TGF beta1 acts upstream of PTHrP to regulate the rate of chondrocyte differentiation. In the antler blastema (<10 days of development), PTHrP, PPR, and TGF beta1 were localized in epidermis, dermis, regenerating epithelium, and in mesenchymal cells but IHH expression was not detected. In the rapidly growing antler (weeks 4-8 of development), PTHrP, PPR, and TGF beta1 were localized in skin, perichondrium, undifferentiated mesenchyme, recently differentiated chondrocytes, and in perivascular cells in cartilage but not in fully differentiated hyperytrophic chondrocytes. IHH was restricted to recently differentiated chondrocytes and to perivascular cells in cartilage. In mineralized cartilage and bone, PTHrP, PPR, IHH, and TGF beta1 were immunolocalized in perivascular cells and differentiated osteoblasts. PTHrP and PPR were also present in the periosteum. TGF beta1 in vitro stimulated PTHrP synthesis by cells from blastema, perichondrium, and cartilage. The findings of this study suggest that molecules which regulate embryonic skeletal development and postnatal epiphyseal growth may also control blastema formation, chondrogenesis, and bone formation in the regenerating deer antler. This finding is further evidence that developmental signaling pathways are recapitulated during adult mammalian bone regeneration.

Parathyroid hormone-related protein (PTHrP) production sites in elasmobranchs.

This study describes the distribution of parathyroid hormone-related protein (PTHrP) antigen and its mRNA in seven species of cartilaginous fish from six elasmobranch families. Antigen was detected using antibodies to synthetic human PTHrP and the mRNA with a riboprobe to human PTHrP gene sequence. The distribution pattern of PTHrP in the cartilaginous fish studied, reflected that observed in mammals but PTHrP further occurs in some sites unique to cartilaginous fish. Of particular note was the demonstration of PTHrP in the shark skeleton, which although considered not to contain bone, may form by a process similar to that forming the early stages of mammalian endochondral bone. The distribution of PTHrP in the elasmobranch skeleton resembled the distribution of PTHrP in the developing mammalian skeleton. Differences in the staining pattern between antisera to N-terminal PTHrP and mid-molecule PTHrP in the brain and pituitary suggested that the PTHrP molecule might be post-translationally processed in these tissues. The successful use of antibodies and a probe to human PTHrP in tissues from the early vertebrates examined in this study suggests that the PTHrP molecule is conserved from elasmobranchs to humans.

Gender differences in older adults' preferences for life-sustaining medical treatments and end-of-life values.

In the present study, we examined gender differences in preferences for life sustaining treatments in response to various health state scenarios and the endorsement of end-of-life values in 99 older adults. Men preferred life-sustaining treatments more than women overall, for specific treatments (i.e., CPR, surgery, and artificial feeding), and in response to specific health scenarios (i.e., current health, Alzheimer's disease, coma with a slight chance of recovery). In terms of values, women indicated a greater desire for a dignified death than men.

Effects of water temperature and salinity on parathyroid hormone-related protein in the circulation and tissues of elasmobranchs.

Parathyroid hormone-related protein (PTHrP) is a hypercalcemic factor in mammals. The PTHrP antigen has been localized in both bony and cartilaginous fish tissues. Sites of localization included gills, skin and kidney, organs involved in osmoregulation. Physiological and localization experiments were carried out in elasmobranchs to dissect PTHrP's possible role in osmoregulation. The effects of alterations in the external environment on PTHrP in sharks were examined by keeping juvenile animals under conditions of increased temperature or decreased salinity. There were no alterations in the PTHrP levels in either the circulation or tissues. Significant correlations between plasma PTHrP, electrolyte and urea levels were seen in the pretreatment samples. The localization of PTHrP by immunohistochemistry and in situ hybridization revealed conserved sites of distribution from elasmobranchs to mammals, including skin, kidney, muscle and skeleton.

Projection in surrogate decisions about life-sustaining medical treatments.

To honor the wishes of an incapacitated patient, surrogate decision makers must predict the treatment decisions patients would make for themselves if able. Social psychological research, however, suggests that surrogates' own treatment preferences may influence their predictions of others' preferences. In 2 studies (1 involving 60 college student surrogates and a parent, the other involving 361 elderly outpatients and their chosen surrogate decision maker), surrogates predicted whether a close other would want life-sustaining treatment in hypothetical end-of-life scenarios and stated their own treatment preferences in the same scenarios. Surrogate predictions more closely resembled surrogates' own treatment wishes than they did the wishes of the individual they were trying to predict. Although the majority of prediction errors reflected inaccurate use of surrogates' own treatment preferences, projection was also found to result in accurate prediction more often than counterprojective predictions. The rationality and accuracy of projection in surrogate decision making is discussed.

Advance directives as acts of communication: a randomized controlled trial.

BACKGROUND: Instructional advance directives are widely advocated as a means of preserving patient self-determination at the end of life based on the assumption that they improve surrogates' understanding of patients' life-sustaining treatment wishes. However, no research has examined whether instructional directives are effective in improving the accuracy of surrogate decisions. PARTICIPANTS AND METHODS: A total of 401 outpatients aged 65 years or older and their self-designated surrogate decision makers (62% spouses, 29% children) were randomized to 1 of 5 experimental conditions. In the control condition, surrogates predicted patients' preferences for 4 life-sustaining medical treatments in 9 illness scenarios without the benefit of a patient-completed advance directive. Accuracy in this condition was compared with that in 4 intervention conditions in which surrogates made predictions after reviewing either a scenario-based or a value-based directive completed by the patient and either discussing or not discussing the contents of the directive with the patient. Perceived benefits of advance directive completion were also measured. RESULTS: None of the interventions produced significant improvements in the accuracy of surrogate substituted judgment in any illness scenario or for any medical treatment. Discussion interventions improved perceived surrogate understanding and comfort for patient-surrogate pairs in which the patient had not completed an advance directive prior to study participation. CONCLUSIONS: Our results challenge current policy and law advocating instructional advance directives as a means of honoring specific patient wishes at the end of life. Future research should explore other methods of improving surrogate decision making and consider the value of other outcomes in evaluating the effectiveness of advance care planning.

Accuracy of primary care and hospital-based physicians' predictions of elderly outpatients' treatment preferences with and without advance directives.

BACKGROUND: Past research has documented that primary care physicians and family members are often inaccurate when making substituted judgments for patients without advance directives (ADs). This study compared the accuracy of substituted judgments made by primary care physicians, hospital-based physicians, and family surrogates on behalf of elderly outpatients and examined the effectiveness of ADs in improving the accuracy of these judgments. PARTICIPANTS AND METHODS: Participants were 24 primary care physicians of 82 elderly outpatients, 17 emergency and critical care physicians who had no prior experience with the patients, and a baseline comparison group of family surrogates. The primary outcome was accuracy of physicians' predictions of patients' preferences for 4 life-sustaining treatments in 9 hypothetical illness scenarios. Physicians made substituted judgments after being provided with no patient AD, patient's value-based AD, or patient's scenario-based AD. RESULTS: Family surrogates' judgments were more accurate than physicians'. Hospital-based physicians making predictions without ADs had the lowest accuracy. Primary care physicians' accuracy was not improved by either AD. Accuracy and confidence in predictions of hospital-based physicians was significantly improved for some scenarios using a scenario-based AD. CONCLUSIONS: Although ADs do not improve the accuracy of substituted judgments for primary care physicians or family surrogates, they increase the accuracy of hospital-based physicians. Primary care physicians are withdrawing from hospital-based care in growing numbers, and emergency medicine and critical care specialists most often are involved in decisions about whether to begin life-sustaining treatments. If ADs can help these physicians better understand patients' preferences, patient autonomy more likely will be preserved when patients become incapacitated.

The stability of older adults' judgments of fates better and worse than death.

Decisions about specific life-sustaining medical treatments have been found to be only moderately stable over time. This study examined whether more general judgments, such as whether a particular health condition is better or worse than death, would exhibit greater stability. Fifty adults (aged 65 yrs and older) made judgments about the perceived quality of life (QOL) possible in a number of hypothetical states of impaired health and their desire to live or die (LOD) in each state. Judgments were made twice from 5 to 16 months apart (M = 10.7 mo). Both QOL and LOD judgments demonstrated only moderate stability regardless of the method of analysis used. Judgments about states characterized by severe impairment became more moderate over time with a substantial minority of participants viewing the states as worse than death at the initial interview viewing them as better than death at follow-up. Participants who did not have a living will, did not have children, had a lower perceived QOL at the follow-up interview, and had a longer time between interviews had more unstable judgments. The implications of these findings for the use of instructional advance directives are discussed.

Older adults' attitudes toward death: links to perceptions of health and concerns about end-of-life issues.

The current study had two primary goals, to determine whether: 1) self-rated mental and physical health, pain, and experience with health problems were predictors of elderly adults' attitudes toward death; and 2) death attitudes predict end-of-life medical treatment concerns. Participants were 109 adults, 65 years of age or older (M=78.74 years), recruited from the local community. Regression analysis indicated that poorer perceived physical health predicted a greater likelihood of viewing death as an escape, and poorer perceived mental health predicted a greater fear of death. Viewing death as an escape and fearing death predicted end-of-life medical treatment concerns; a greater endorsement of either attitude predicted more concern. Possible explanations for the links between perceived health, attitudes toward death, and concern about end-of-life issues are suggested.

Modal preferences predict elderly patients' life-sustaining treatment choices as well as patients' chosen surrogates do.

The purpose of this study was to compare the accuracy of an actuarial method of predicting patients' preferences for life-sustaining treatment with the accuracy of surrogate decision makers. 401 outpatients 65 years old or older (mean = 73 years) and their self-designated surrogate decision makers recorded preferences for four life-sustaining medical treatments in nine hypothetical illness scenarios. The surrogates did not predict the patients' preferences more accurately than did an actuarial model using modal preferences. Surrogates' accuracy was not influenced by the use of an advance directive (AD) or discussion of life-sustaining treatment choices. In clinical practice, an actuarial model could assist surrogate decision makers when a patient has no AD, an AD is unavailable, a patient's AD is vague or describes treatment choices for only extreme or unlikely disease states, no proxy decision maker has been designated, or a patient was never competent.

Genomic structure and expression of parathyroid hormone-related protein gene (PTHrP) in a teleost, Fugu rubripes.

In this study we describe the isolation and characterisation of the parathyroid hormone-related protein (PTHrP) gene from the teleost Fugu rubripes. The gene has a relatively simple structure, compared with tetrapod PTHrP genes, composed of three exons and two introns, encompassing 2.25kb of genomic DNA. The gene encodes a protein of 163 amino acids, with a putative signal peptide of 37 amino acids and a mature peptide of 126 amino acids. The overall homology with known tetrapod PTHrP proteins is low (36%), with a novel sequence inserted between positions 38 and 65, the absence of the conserved pentapeptide (TRSAW) and shortened C-terminal domain. The N-terminus shows greater conservation (62%), suggesting that it may have a hypercalcaemic function similar to that of tetrapod PTHrP. In situ localisation and RT-PCR have demonstrated the presence of PTHrP in a wide range of tissues with varying levels of expression. Sequence scanning of overlapping cosmids has identified three additional genes, TMPO, LDHB and KCNA1, which map to human chromosome 12, with the latter two mapping to 12p12-11.2. PTHrP in human also maps to this chromosome 12 sub-region, thus demonstrating conservation of synteny between human and Fugu.

Cloning of the cDNA for sea bream (Sparus aurata) parathyroid hormone-related protein.

This paper reports cloning of the cDNA for sea bream (Sparus aurata) parathyroid hormone-related protein (PTHrP). The gene codes for a 125-amino acid mature protein with a 35-residue prepeptide. The total gene sequence is 1.8 kb with approximately 75% noncoding. The N-terminus of the protein resembles mammalian and chicken PTHrP peptides with 12 of the first 21 amino acids identical and for which there is homology with mammalian parathyroid hormone. Toward the C-terminus, the nuclear transporter region between residues 79 and 93 in sea bream is 73% homologous to tetrapod PTHrP, and the RNA binding domain, 96-117, is 50% homologous, moreover starting with the conserved lysine and terminating with the lysine/arginine sequence. Sea bream PTHrP differs significantly from mammalian and chicken PTHrP, having a novel 16-amino acid segment between residues 38 and 54 and completely lacking the terminal domain associated in mammals with inhibition of bone matrix lysis. RT-PCR and in situ hybridization of sea bream tissues show that the gene is expressed widely and the results confirm observations of a PTHrP-like factor in sea bream detected with antisera to human PTHrP.

Community care and mental disorder: an analysis of discursive resources.

The number of people with mental disorders living in the community has recently increased with further increases likely. This study provides a post-attitudinal examination of the discursive resources on which ordinary New Zealanders draw when talking about 'community care'. Four common resources were identified: dual community, rights, disorder and patronization. Each of these resources is examined by using a range of analytic concepts which illustrate the rhetorical achievements and social practices found in the data. We argue that the dual community resource works to position the disordered as being outside the community which is contrary to the broad aim of community care. The analysis of talk of rights was cast as an ideological dilemma for participants who endorsed both universality and conditionality of rights for the disordered. The disorder resource was notable for its flexible rhetorical deployment, while patronization contributed to the positioning of the disordered as subordinate. The implications of these resources are discussed in terms of existing notions of stigma and possibilities for change centred around affiliative resources.