Radiological evaluation on allograft reconstruction of the acetabulum combined with supporting device in revision total hip replacement.

We reviewed the radiographs of 25 hips of 20 patients who had received revisions of the acetabular components of total hip replacement supplemented by allograft for bone defects. Bone defects in 20 hips (80%) were classified into type D (cranio-central defect) according to Itoman's classification. In eight, sockets were installed directly on the allografts (group A). A metallic supporting device was used for reinforcing the grafts in 17 hips (group B). The position of the acetabular socket was measured on a radiograph, taken immediately after revision surgery and again at the latest follow-up. Using a MEM template, cranial and central migrations were determined. Mean cranial migration in hips of group A was 3.6 mm. Group B was 0.2 mm. Maintenance of thickness of the allografts was 60.6% in the cranial region and 75% in the central in group A. In the hips of group B, however, almost 100% of the initial thickness was maintained cranially and centrally. Allograft reconstruction of acetabular bone defect in revision total hip replacement is a beneficial procedure. The remaining pelvic bone is usually in poor condition, therefore, it is necessary to ensure primary fixation by the metallic supporting device.     

国产Fogarty气囊导管对犬腹主动脉壁损伤的超微结构观察

为探讨国产Fogany导管的气囊直径大小及导管通过血管腔次数多少与动脉管壁急性损伤的关系,本文以14条犬为对象,研究了当Fogany导管气囊直径分别等于血管直径的1、1.5及2倍、导管通过血管腔1、2及3次时,该导管对犬腹主动脉壁所致的超微结构损伤改变。结果显示:气囊直径愈大,导管通过血管腔次数愈多,气囊对动脉内膜及肌层的损伤愈重;从轻微的内皮细胞损伤至内皮及内皮下组织的全部剥脱,以及中膜层平滑肌细胞受损,但大多数损伤局限于内膜层。本研究为此种国产Fogany气囊导管应用于临床提供了实验依据。     

Lithium but not cholinergic ligands influence guanylate cyclase activity in intact human lymphocytes

The presence of guanylate cyclase in intact circulating human lymphocytes and the sensitivity of this enzyme to stimulation by sodium nitroprusside could be confirmed. However, in contrast to other observations all attempts failed to stimulate the enzyme by cholinergic agonists, despite the use of M1 as well as M2 selective agonists. These findings do not support the assumption that cholinergic recognition sites on human lymphocytes described by many groups are part of a functioning muscarinic transducing mechanism. While several other neuroreceptor agonists were also unable to affect lymphocyte guanylate cyclase activity, lithium was found to potently inhibit the stimulation of guanylate cyclase by sodium nitroprusside at an intracellular concentration close to the therapeutic plasma levels. It is suggested that the effects of lithium on guanylate cyclase activity in human lymphocytes could be related to a possible mechanism of action of lithium in affective disorders.     

Internal and external information processing by lateral hypothalamic glucose-sensitive and insensitive neurons during bar press feeding in the monkey

Single neuron activities in the lateral hypothalamic area (LHA) were recorded during bar press feeding task in the monkey. First registered neurons were sorted into 2 groups, glucose-sensitive (GS) and glucose-insensitive (GIS) neurons, depending on their glucose sensitivity. Then firing variations to feeding, electrophoretically applied catecholamines and opiate, and to odor and taste stimuli were investigated. GS neurons responded to dopamine, noradrenaline and morphine more often than GIS neurons. In feeding task GS neurons responded during bar press (BP) and reward (RW) periods with long-lasting inhibition of firing and at cue tone (CT) with transient inhibition, while GIS neurons responded during BP and RW periods mainly with excitation and at cue light (CL) with excitation. A majority of GS neurons responded to both odor and taste stimuli more often than GIS neurons. Data suggest that these two kinds of neurons in the LHA may be involved in different functional aspects of feeding: GS neurons, mainly in internal information processing and reward mechanism, and GIS neurons, in external information processing and motor aspects.     

Anatomic and spiral computed tomographic study of the genial tubercles for genioglossus advancement.

OBJECTIVE: To measure and compare Chinese mandibular genial tubercles measured anatomically and with computed tomography (CT). STUDY DESIGN AND SETTING: Spiral CT scans were taken of 40 adult human skulls; the superior genial spines were measured using anatomic and CT methods. RESULTS: The height and width of the superior genial spines, mandible thickness, and distance from the menton to the inferior and superior margins of the superior genial spines were 5.82 +/- 0.71, 6.98 +/- 1.35, 11.95 +/- 1.59, 11.08 +/- 2.05, and 16.91 +/- 2.30 mm from anatomic measurements and 6.17 +/- 0.71, 7.01 +/- 1.13, 12.19 +/- 1.64, 10.41 +/- 1.55, and 15.73 +/- 2.12 mm using spiral CT, respectively. The anatomic and CT measurements were correlated. CONCLUSION: Spiral CT of the genial tubercles can help locate the osteotomy in genioglossus advancement. SIGNIFICANCE: This study acquired reference data on Chinese genial tubercles demonstrating that CT measurements of the genial tubercles reflect their anatomy, which should allow accurately locate the osteotomy.     

Modulation of glial cell signaling by adenosine and pharmacological reinforcement

In view of the increasing evidence that a pathological glial activation plays a significant role in the development of neurodegenerative diseases, we investigated the underlying molecular signaling as a possible target for a pharmacological therapy. Here, we are particularly focusing on the endogenous modulation of the Ca²⁺ and cyclic nucleotide-dependent signaling by the nucleoside adenosine and its reinforcement by the xanthine derivative propentofylline (PPF). As an experimental model, we used cultured rat microglial cells and astrocytes that are immature, show a high proliferation rate, and resemble in several aspects pathologically activated glial cells. A prolonged increase of the cellular cAMP level favored the differentiation of cultured astrocytes and associated properties required for the physiological nerve cell function. On the other hand, a strengthening of the cyclic nucleotide-dependent signaling inhibited potentially neurotoxic properties of cultured microglial cells. Similar effects were obtained by treatment with propentofylline, which mimicked modulatory adenosine effects and increased the intracellular level of cAMP and cGMP. Such a pharmacological glial cell conditioning, obtained by modifying the strength and the timing of these second messengers, may provide a therapy of neurodegenerative diseases in which a pathological activation of microglial cells and astrocytes is discussed to play a pathogenic role.     

Synthesis and polymerization behavior of 2,3-dihydro-1,4-dioxin-2-one and its 3-methyl derivative

The hitherto unknown 2,3-dihydro-1,4-dioxin-2-one ( 7 ) and its 3-methyl derivative 8 have been synthesized for the first time. The olefinic double bond is inserted into the saturated 1,4-dioxanone precursors 3 and 6a/b by a retro-Diels-Alder reaction in the last step of the synthesis. The 1,4-dioxanone systems of 3 and 6 are prepared by reacting a vicinal dialkoxide with α-halogenated acyl halides, thus forming the ester and the ether bond in a one-pot reaction. Monomers 7 and 8 are polymerized by cationic initiation. The resulting products undergo fragmentation to form oligomers in the presence of protic solvents, indicting that ring-opening polymerization of the δ-lactone apparently leads to polyester chain segments.     

Direct ultrastructural evidence of target-directed polarization by cytotoxic lymphocytes in lesions of human graft-vs-host disease

Cytotoxic lymphocytes are thought to kill target cells by means of potent cytotoxic granules that congregate near the microtubular organizing center and the Golgi apparatus at one pole of the killer cell. We searched for evidence of this type of polarization in 12 lip biopsy specimens from patients with acute and/or chronic graft-vs-host disease (GVHD) compared with two lip specimens from normal individuals. Lymphocytes with such polarization were found in contact with epithelial cells of the squamous mucosa in all 12 cases of GVHD, and cells of the cuboidal minor salivary duct epithelium were found in two of 11 evaluable cases. The data add support to the hypothesis that cytolytic lymphocytes attack epithelial cells in GVHD.