Reliability of the acetabular teardrop as a landmark

Summary This study investigated the effect of tilt and observer reliability on radiographic measurements of the position of a prosthetic acetabular cup in seven dry bone pelves using the teardrop as a landmark. Coronal or sagittal tilt of more than five degrees was easily recognisable and there was effectively no observer variation in the measurements up to this limit. In addition, 90 out of 100 randomly selected antero-posterior pelvic radiographs from an outpatient department were not significantly rotated and 93 demonstrated a clearly defined teardrop. Measurements about the teardrop on routine radiographs are therefore sufficiently accurate to allow assessment of prosthetic position.

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La valeur du sourcil cotyloidien comme repère d'analyse radiologique

Résumé Cette étude, conduite sur 7 bassins secs, apprécie l'effet de l'inclinaison du bassin sur la qualité de l'analyse radiographique de la position d'une cupule prothétique de hanche en utilisant le sourcil cotyloïdien comme repère. Une inclinaison du bassin dans les plans coronal et sagittal est aisément détectable et il n'existe pas de variation d'analyse entre les différents observateurs en dessous de 5° d'inclinaison. De plus, sur 100 radiographies antéro-postérieures de bassin choisies au hasard dans les dossiers de consultation, 90 avaient été réalisées sans incidence particulièrement adaptée et l'on pouvait repérer facilement le sourcil sur 93% d'entre elles. Les mesures faites sur des radios de routine sont donc suffisamment précises pour permettre l'évaluation de la position d'une prothèse à partir du sourcil cotyloïdien.

     

Naturopaths practice behaviour: provision and access to information on complementary and alternative medicines

Background  

The increasing use of complementary and alternative medicines in Australia has generated concern regarding the information on these products available to both healthcare providers and the public. The aim of this study was to examine the practice behaviours of naturopaths in relation to both the provision of and access to information on complementary and alternative medicines (CAM).     

Natural killer cells in murine muscular dystrophy. IV. Characterization of Percoll fractionated splenic and thymic natural killer cells and natural killer-sensitive thymocyte targets

The Natural Killer (NK) activity in the thymus and NK-sensitive thymocyte targets of dystrophic mice was investigated. Dystrophic and normal mouse thymocytes or spleen cells were layered on discontinuous Percoll gradients (5 or 10% increments, respectively) between 40 and 70% and centrifuged at 1700 g for 30 min. All fractions were tested for either NK activity or used a 51Cr-labeled NK-sensitive targets in a 6-hr 51Cr release assay. The density interface between the 50% (1.060 g/ml) and 60% (1.075 g/ml) Percoll fractions of either dystrophic or normal mouse spleen cells and the 40% (1.050 g/ml) and 50% (1.060 g/ml) Percoll fractions of either dystrophic or normal mouse thymocytes were found to contain the largest proportion of NK activity using YAC-1 lymphoma tumor cells as targets. In addition, the NK activity in dystrophic mouse spleen cells and thymocytes was significantly greater when compared with normal mouse controls. Target binding cell studies revealed that these Percoll fractions of dystrophic mouse spleen cells and thymocytes had greater numbers of conjugate-forming cells when compared with normal control groups. Cell depletion experiments using either anti-Thy 1.2, anti-asialo-GM 1 or anti-NK-1 plus complement treatment revealed that the cell responsible for NK activity in the 50% Percoll fraction interface of dystrophic mouse spleen cells was asialo-GM 1 positive. NK-1 positive, and partially Thy 1.2 positive. However, the cells displaying NK-activity in the thymus of normal or dystrophic mice were found to be highly Thy-1.2 positive and peanut agglutinin (PNA) negative. The density interface between the 60% (1.075 g/ml) and 65% (1.081 g/ml) Percoll fractions of either normal or dystrophic mouse thymocytes contained the largest proportion of NK-sensitive target cells. Interestingly, the 60% Percoll fraction of dystrophic mouse thymocyte targets was significantly more susceptible to NK-mediated lysis than that of the normal mouse thymocyte population. Cell depletion experiments revealed that the NK-sensitive thymocyte population was similar in both mice, that is, Thy-1.2 positive, cortisone sensitive, PNA positive, Dolichos biflorus (DBA) negative and asialo GM-1 negative. The results indicate that there are density differences between splenic and thymic NK cells. In addition, there are density and phenotypic differences between thymic NK cells and thymic NK-sensitive target cells. The findings support the hypothesis that there are different populations of NK cells.     

Adrenal Medullary Nodules in Beckwith-Wiedemann Syndrome Resemble Extra-Adrenal Paraganglia

Clues to mechanisms regulating development and tumorigenesis may be provided by studies of unusual diseases. Beckwith-Wiedemann syndrome (BWS) is a rare congenital disorder apparently related to abnormal regulation of insulin-like growth factor-2 (IGF-2) production. IGF-2 mRNA has been previously localized to the chief cells of extra-adrenal paraganglia and to adult, but not fetal, adrenal medulla. Expression of IGF-2 by neuroblastomas has been hypothesized to reflect extra-adrenal paraganglionic differentiation. In the adrenals of a fetus with BWS, we have observed both increased numbers of chromaffin cells and organoid nodules resembling extra-adrenal paraganglia. Immunoreactive IGF-2 was observed in both cell types, but was also observed in chromaffin cells in the normal fetal adrenal. The findings suggest autocrine or paracrine influences of IGF-2 in regulating the number and phenotype of cells derived from sympathoadrenal precursors in the developing adrenal medulla as well as in extra-adrenal paraganglia. These results have implications for the interpretation of data from neuroblastoma studies.     

Osteosarcomatosis

A review of the 690 cases of osteosarcoma in the radiographic file of the Armed Forces Institute of Pathology revealed 29 cases of "osteosarcomatosis" (multiple skeletal sites of osteosarcoma). Fifteen of these patients were 18 years old and under and manifested rapidly appearing, usually symmetric, sclerotic metaphyseal lesions. The remaining 14 patients were more than 18 years old and had fewer, asymmetric sclerotic lesions. In most patients (28 of 29), a radiographically dominant skeletal tumor was seen. Pulmonary metastases occurred in the majority of patients and were detected at the same time as the bone lesions. These 29 patients were studied with regard to demographic data and skeletal distribution and radiographic appearance of their lesions. As a result of the findings, a metastatic origin from a primary dominant osteosarcoma is favored over a multifocal origin as the basis for osteosarcomatosis. Osteosarcomatosis is more commonly encountered in the mature skeleton than has been previously recognized.     

Marrow regeneration after mechanical depletion

The origin of marrow regeneration after mechanical depletion was reinvestigated in mouse chimeras. The results were compatible with the local origin of stem cells from remnants of incompletely removed marrow, but not with their origin from a common precursor of both bone and hemopoietic cell lines. In transplanted femurs depleted by a modified technique of in vivo evacuation of marrow, hemopoietic regeneration failed to occur. The presence of hemopoietic stem cells in the Haversian canals was thus excluded. The demonstration of ample hemopoiesis with minimal bone formation in nondepleted controls in which bone marrow initially became necrotic provided new evidence that osteogenesis was not a prerequisite of hemopoietic regeneration.     

Targeted liposomal c-myc antisense oligodeoxynucleotides induce apoptosis and inhibit tumor growth and metastases in human melanoma models.

PURPOSE: Melanoma is a highly malignant and increasingly common tumor. Because the cure rate of metastatic melanoma by conventional treatment is very low, new therapeutic approaches are needed. We previously reported that coated cationic liposomes (CCL) targeted with a monoclonal antibody against the disialoganglioside (GD(2)) and containing c-myb antisense oligodeoxynucleotides (asODNs) resulted in a selective inhibition of the proliferation of GD(2)-positive neuroblastoma cells in vitro. EXPERIMENTAL DESIGN: Here, we tested the in vivo antitumor effects of this novel antisense liposomal formulation by targeting the c-myc oncogene on melanoma, a neuroectodermal tumor sharing with neuroblastoma the expression of GD(2). RESULTS: Our methods produced GD(2)-targeted liposomes that stably entrapped 90% of added c-myc asODNs. These liposomes showed a selective binding for GD(2)-positive melanoma cells in vitro. Melanoma cell proliferation was inhibited to a greater extent by GD(2)-targeted liposomes containing c-myc asODNs (aGD(2)-CCL-myc-as) than by nontargeted liposomes or free asODNs. The pharmacokinetic results obtained after i.v. injection of [(3)H]-myc-asODNs, free or encapsulated in nontargeted CCLs or GD(2)-targeted CCLs, showed that free c-myc-asODNs were rapidly cleared, with less than 10% of the injected dose remaining in blood at 30 min after injection. c-myc-asODNs encapsulated within either CCL or aGD(2)-CCL demonstrated a more favorable profile in blood, with about 20% of the injected dose of each preparation remaining in vivo at 24 h after injection. In an in vivo melanoma experimental metastatic model, aGD(2)-CCL-myc-as, at a total dose of only 10 mg of asODN per kilogram, significantly inhibited the development of microscopic metastases in the lung compared with animals treated with myc-asODNs, free or entrapped in nontargeted liposomes, or aGD(2)-CCL encapsulating scrambled asODNs (P < 0.01). Moreover, mice bearing established s.c. human melanoma xenografts treated with aGD(2)-CCL-myc-as exhibited significantly reduced tumor growth and increased survival (P < 0.01 versus control mice). The mechanism for the antitumor effects appears to be down-regulation of the expression of the c-myc protein and interruption of c-myc-mediated signaling: induction of p53 and inhibition of Bcl-2 proteins, leading to extensive tumor cell apoptosis. CONCLUSION: These results suggest that inhibition of c-myc proto-oncogene by GD(2)-targeted antisense therapy could provide an effective approach for the treatment of melanoma in an adjuvant setting.