Non-Hodgkin's lymphoma with left suprascapular neuropathy on magnetic resonance imaging.
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Magnetic resonance imaging is gaining importance in the diagnosis of nerve and muscular disorders. The ability of magnetic resonance imaging to delineate the different muscles and the nerve in any plane has made the differentiation between the changes of neuropathy, denervation, and nerve entrapment possible. Although findings on magnetic resonance imaging are non-specific, their use, coupled with clinical symptoms and electromyographic findings, allow an accurate diagnosis to be made without resorting to invasive biopsies. (+info)
Rare variation of the arm artery: coexistence with the superficial brachial and superficial subscapular arteries in the absence of the normal brachial artery.
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A rare variation in the arterial pattern was found in the right arm of an 87-year-old male cadaver in a student dissection practice. In this case, the superficial brachial and superficial subscapular arteries coexisted in the absence of the normal brachial artery (A. brachialis profunda). After branching off a large-sized superficial subscapular artery, the axillary artery did not penetrate the brachial plexus and gave rise to a superficial brachial artery, which arose from the axillary artery at the point between the ansa pectoralis and ansa mediana, and descended ventral to the median nerve branching off the profunda brachii and superior and inferior ulnar collateral arteries. The superficial brachial artery finally divided into the radial and ulnar arteries in the cubital fossa. The superficial subscapular artery passed inferior and dorsal to the medial cord of the brachial plexus, giving off the lateral thoracic artery, and then branched off into the thoracodorsal, circumflex scapular and posterior circumflex humeral arteries. Thus the main nerves of the brachial plexus were sandwiched between the superficial brachial artery and the superficial subscapular artery system. The morphological and clinical significance of this variant are discussed. (+info)
Carboxypeptidase Z (CPZ) modulates Wnt signaling and regulates the development of skeletal elements in the chicken.
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Carboxypeptidase Z (CPZ) is a secreted Zn-dependent enzyme whose biological function is largely unknown. CPZ has a bipartite structure consisting of an N-terminal cysteine-rich domain (CRD) and a C-terminal catalytic domain. In the early chicken embryo CPZ is initially expressed throughout the somites and subsequently becomes restricted to the sclerotome. To initiate a functional analysis of CPZ, a CPZ producing retroviral vector was applied to the presomitic mesoderm at the level of the future wing. This resulted in a loss of the scapular blade and of rostral ribs. Such dysmorphogenesis is preceded by ectopic Pax3 expression in the hypaxial part of the dermomyotome, a region from which the blade of the scapula normally derives. A mutant CPZ, lacking a critical active site glutamate, fails to induce Pax3 expression and does not cause skeletal defects. The induction of Pax3, a Wnt-responsive gene in somites, and the presence of a CRD prompted us to examine whether CPZ affects Wnt signaling. In an in vitro assay we found that CPZ, but not its inactive mutant form, enhances the Wnt-dependent induction of the homeobox gene Cdx1. In addition, immunoprecipitation experiments suggest that the CRD of CPZ acts as a binding domain for Wnt. Taken together these data provide the first evidence for CPZ playing a role in Wnt signaling. (+info)
Isolation and characterization of an inhibitor of neovascularization from scapular chondrocytes.
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An inhibitor of neovascularization from the conditioned media of scapular chondrocytes established and maintained in serum-free culture has been isolated and characterized. To determine whether this chondrocyte-derived inhibitor (ChDI) was capable of inhibiting neovascularization in vivo, this protein was assayed in the chick chorioallantoic membrane assay. ChDI was a potent inhibitor of angiogenesis in vivo (4 micrograms = 87% avascular zones). This inhibitor is also an inhibitor of fibroblast growth factor-stimulated capillary endothelial cell (EC) proliferation and migration, as well as being an inhibitor of mammalian collagenase. ChDI significantly suppressed capillary EC proliferation in a dose-dependent, reversible manner with an IC50 (the inhibitory concentration at which 50% inhibition is achieved) of 2.025 micrograms/ml. Inhibition by ChDI of growth factor-stimulated capillary EC migration was also observed using a modified Boyden chamber assay (IC50 = 255 ng/ml). SDS-PAGE analysis followed by silver staining of ChDI purified to apparent homogeneity revealed a single band having an M(r) of 35,550. Gel elution experiments demonstrated that only protein eluting at this molecular weight was anti-angiogenic. These studies are the first demonstration that chondrocytes in culture can produce a highly enriched, potent inhibitor of neovascularization which also inhibits collagenase. (+info)
Visualization of interscapular brown adipose tissue using (99m)Tc-tetrofosmin in pediatric patients.
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Brown adipose tissue (BAT) is a site of nonshivering thermogenesis in mammals. The mitochondria of BAT operate in an uncoupled mode and increase fatty acid oxidation to produce heat at birth. Thus, the BAT of human infants and children contains more active mitochondria than that of adults. We surmised that because (99m)Tc-tetrofosmin can be absorbed by functional mitochondria in the myocardium and in tumor cells, it could reveal mitochondrial function in BAT. METHODS: Between January 1999 and December 2002, we retrospectively analyzed 385 consecutive studies of (99m)Tc-tetrofosmin uptake in pediatric patients with cardiac disorders. All patients with symmetric (99m)Tc-tetrofosmin accumulation within the neck and shoulder region according to planar images were selected, and the features of the uptake were analyzed. RESULTS: Increased symmetric (99m)Tc-tetrofosmin uptake in the interscapular BAT was a typical profile of 65 of the 385 patients (17%). The frequency of (99m)Tc-tetrofosmin uptake was significantly higher in winter than in spring or summer (P < 0.05) and prominent in newborns. The frequency peaked between 0 and 2 y of age and then declined with age. CONCLUSION: Gamma-camera imaging with (99m)Tc-tetrofosmin can reveal interscapular BAT distribution in infants and children in terms of mitochondrial activity. (+info)
Feeding behaviour of free-ranging walruses with notes on apparent dextrality of flipper use.
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BACKGROUND: Direct observations of underwater behaviour of free-living marine mammals are rare. This is particularly true for large and potentially dangerous species such as the walrus (Odobenus rosmarus). Walruses are highly specialised predators on benthic invertebrates - especially bivalves. The unique feeding niche of walruses has led to speculations as to their underwater foraging behaviour. Based on observations of walruses in captivity and signs of predation left on the sea floor by free-living walruses, various types of feeding behaviour have been suggested in the literature. In this study, however, the underwater feeding behaviour of wild adult male Atlantic walruses (O. r. rosmarus) is documented for the first time in their natural habitat by scuba-divers. The video recordings indicated a predisposition for use of the right front flipper during feeding. This tendency towards dextrality was explored further by examining a museum collection of extremities of walrus skeletons. RESULTS: During July and August 2001, twelve video-recordings of foraging adult male walruses were made in Young Sound (74 degrees 18 N; 20 degrees 15 V), Northeast Greenland. The recordings did not allow for differentiation among animals, however based on notes by the photographer at least five different individuals were involved. The walruses showed four different foraging behaviours; removing sediment by beating the right flipper, removing sediment by beating the left flipper, removing sediment by use of a water-jet from the mouth and rooting through sediment with the muzzle. There was a significant preference for using right flipper over left flipper during foraging. Measurements of the dimensions of forelimbs from 23 walrus skeletons revealed that the length of the right scapula, humerus, and ulna was significantly greater than that of the left, supporting our field observations of walruses showing a tendency of dextrality in flipper use. CONCLUSION: We suggest that the four feeding behaviours observed are typical of walruses in general, although walruses in other parts of their range may have evolved other types of feeding behaviour. While based on small sample sizes both the underwater observations and skeletal measurements suggest lateralized limb use, which is the first time this has been reported in a pinniped. (+info)
Two cases of suprascapular neuropathy in a family.
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Suprascapular entrapment neuropathy is well known in certain athletes, especially volleyball players. A brother and sister presented with right shoulder pain and wasting of the scapular muscles, particularly the infraspinatus. They had played volleyball for over six years and were forced to retire because of disability. Investigations showed involvement of the rhomboid muscles also, suggesting a probable extension of this syndrome to other nerves in the region such as the dorsal scapular nerve. (+info)
Rheumatoid arthritis of the shoulder joint: comparison of conventional radiography, ultrasound, and dynamic contrast-enhanced magnetic resonance imaging.
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OBJECTIVE: To determine the role of ultrasound and magnetic resonance imaging (MRI) compared with conventional radiography in the detection of chronic and acute inflammatory manifestations of rheumatoid arthritis (RA) of the shoulder joint. METHODS: Forty-three consecutive patients with known RA prospectively underwent clinical examination, radiography, ultrasound, and MRI of the shoulder joints. Each patient was assigned a clinical/laboratory score consisting of 7 parameters, including measurements of shoulder mobility, the erythrocyte sedimentation rate, and C-reactive protein level. Conventional radiography was standardized and performed in 2 planes. Ultrasound was performed in 10 predefined planes using a 7.5-MHz linear transducer. MRI at 1.5T comprised transverse and oblique coronal T1- and T2*-weighted fast spin-echo, gradient-echo (GRE), and inversion-recovery sequences with a matrix size of up to 512 pixels. A dynamic T1-weighted GRE sequence was acquired with intravenous administration of contrast medium. Erosions were assessed using all 3 imaging techniques on a 4-point scale. Soft-tissue involvement was evaluated according to the presence of synovitis, tenosynovitis, and bursitis on ultrasound and MRI. The results in the study group were compared with those obtained in a control group of 10 patients with shoulder pain. RESULTS: In the study group, erosions of the humeroscapular joint were detected by conventional radiography in 26 patients, by ultrasound in 30 patients, and by MRI in 39 patients; the differences were statistically significant for the comparisons of conventional radiography with MRI and for ultrasound versus MRI (P < 0.0001). Conventional radiography detected 12 erosions of the scapula and MRI detected 15. Synovitis was demonstrated in 12 patients by ultrasound and in 27 patients by MRI (P = 0.0003). Tenosynovitis was observed in 15 patients by ultrasound and in 28 patients by MRI (P = 0.0064). Bursitis was detected in 13 patients by ultrasound and in 18 patients by MRI. The findings on dynamic contrast-enhanced MRI correlated significantly with the detection of synovitis by ultrasound and erosions by static MRI (P < 0.05). CONCLUSION: Ultrasound and MRI supplement conventional radiography in assessing the shoulder joint. Although conventional radiography can be used as the sole method of following up known joint destruction in RA, ultrasound and, preferably, MRI are recommended as additional techniques in the initial diagnostic evaluation when radiography yields negative results. (+info)