The murine neutrophil-chemoattractant chemokines LIX, KC, and MIP-2 have distinct induction kinetics, tissue distributions, and tissue-specific sensitivities to glucocorticoid regulation in endotoxemia

Lipopolysaccharide-induced CXC chemokine (LIX) is a novel murine neutrophil-chemoattractant CXC chemokine cloned as a glucocorticoid-attenuated response gene. We investigated LIX message expression in an acute endotoxemia model. LIX message peaks later than KC or macrophage inflammatory protein-2 (MIP-2) and remains elevated longer in almost all tissues. Induced LIX message expression in heart is 5- to 6-fold greater than in lung and spleen, and 20-fold greater than in liver. In contrast, KC expression is equal in heart, lung, and liver, whereas MIP-2 expression is strongest in the lung. Glucocorticoid regulation of these genes also differs. Endotoxemia-induced LIX message expression in the lung is markedly enhanced in adrenalectomized mice and strongly attenuated by dexamethasone, whereas lung KC and MIP-2 expression are unaffected by glucocorticoids. It is surprising to note that endotoxemia-induced brain expression of LIX (but not KC or MIP-2) is increased by dexamethasone. These observations suggest that LIX may have biological roles distinct from KC and MIP-2.     

Guided tissue regeneration in Class II furcation involved maxillary molars: a controlled study of 8 split-mouth cases

The purpose of this study was to clinically evaluate the effectiveness of polytetrafluoroethylene membranes in the healing of interproximal Class II furcation defects in maxillary molars using a surgical treatment technique based on the principles of guided tissue regeneration. Eight subjects with similar bilateral Class II furcation lesions on the mesial aspect of maxillary first molars participated in this study. Patients received initial therapy consisting of oral hygiene instructions, scaling and root planing, and occlusal adjustment if necessary. Clinical parameters evaluated included plaque index, sulcular bleeding index, probing depth, attachment level, gingival recession, and open horizontal and vertical furcation fill. An acrylic occlusal stent was used to assure reproducibility of measurements. Experimental sites received a polytetrafluoroethylene membrane following surgical exposure of the furcation. Control sites were treated in the exact same manner but without a membrane. Membranes were removed at 6 weeks after the first surgery. Reentry surgeries were performed at 9 months. Postsurgical results showed a significant improvement in probing depth, attachment level, and open horizontal furcation fill for both groups when compared to baseline values, with experimental sites performing significantly better than controls. Control sites showed a slight loss in open vertical furcation fill while experimental sites remained unchanged. This study suggests that guided tissue regeneration using polytetrafluoroethylene membranes is of some but limited value in the treatment of maxillary molar interpoximal Class II furcation lesions.     

Monteggia fractures in adults

The records concerning ten consecutive years of experience with Monteggia fractures in adult patients at a level-one trauma center were retrospectively reviewed. Forty-eight patients who had been followed for a minimum of two years (average, 6.5 years; range, two to fourteen years) were identified. There were twenty-five women and twenty-three men, and the average age was fifty-two years (range, eighteen to eighty-eight years). According to the classification of Bado, there were seven type-I, thirty-eight type-II, one type-III, and two type-IV injuries. Twenty-six patients (68 percent) who had a Bado type-II fracture had an associated fracture of the radial head; ten of these patients also had a fracture of the coronoid process as a single large fragment. The ulna was fixed with a tension band-wire construct supplemented with screws in three patients (all of whom had a Bado type-II fracture). An ulnar diaphyseal fracture was fixed with an intramedullary Steinmann pin in one patient. The remaining patients had fixation with a plate and screws. The fracture of the radial head was treated with either complete or partial excision of the fragments in twelve patients (with replacement with a silicone prosthesis in two), open reduction and internal fixation in ten patients, and no intervention in four patients. Nine patients, all of whom had a Bado type-II fracture, needed a reoperation within three months after the initial operation; five had revision of a loose ulnar fixation device, three had resection of the radial head, and one had removal of a wire that had migrated from the radial head into the elbow articulation. Other important complications included proximal radioulnar synostosis in three patients, ulnar malunion in three, posterolateral rotatory instability of the ulnohumeral joint in one, and instability of the distal radioulnar joint in one. At the most recent follow-up examination, which was performed after all of the reoperations and reconstructive procedures had been done, the average score according to the system of Broberg and Morrey was 86 points (range, 15 to 100 points). The result was excellent for eighteen patients, good for twenty-two, fair for two, and poor for six. Six of the eight patients who had an unsatisfactory (fair or poor) result had had a Bado type-II fracture with a concomitant fracture of the radial head. These unsatisfactory results were related to a malunited fracture of the coronoid process in two patients, a proximal radioulnar synostosis in one, a malunited fracture of the coronoid process and a proximal radioulnar synostosis in one, a malunion of the ulna in one, and painfully restricted rotation of the forearm after operative fixation of a comminuted fracture of the radial head in one. The other two unsatisfactory results were in a patient who had had a Bado type-I fracture and in one who had had a Bado type-IV fracture. The results of the present series are much better than those reported in most earlier studies, suggesting that stable anatomical fixation of the ulnar fracture (including associated fracture fragments of the coronoid process) with a plate and screws inserted with use of current techniques of fixation leads to a satisfactory result in most adults who have a Monteggia fracture. The posterior (Bado type-II) fracture is the most common type of Monteggia fracture in adults. Problems with the elbow related to fractures of the coronoid process and the radial head, which are common with Bado type-II Monteggia fractures, remain the most challenging elements in the treatment of these injuries.     

Differential north to south gastric cancer-duodenal ulcer gradient in China. China Ulcer Study Group

There are suggestions that duodenal ulcer protects individuals from gastric cancer and that rice is ulcerogenic while wheat is gastro-protective. We aimed to examine the relationship of gastric cancer, duodenal and gastric ulcers in different geographical regions in China and identified dietary risk factors for duodenal ulcer and gastric cancer. The prevalence of peptic ulcer and gastric cancer among symptomatic patients in eight major cities, four each from the north and the south representing all the six defined regions of China were studied. Endoscopy and case records over a 10 year period were reviewed and cases of confirmed duodenal and gastric ulcer and gastric cancer, together with the total number of endoscopies performed per year, were recorded. Rates were expressed as cases/1000 endoscopies. Results were compared to another epidemiological study on diet and mortality in the same regions in China conducted at the same time. Duodenal ulcer rates were 2.4-fold higher in southern China than northern China, whereas gastric cancer rates were 1.6-fold higher in the north than in the south. Correlation studies showed for the first time an inverse linear relationship between the gastric cancer rates and the duodenal ulcer rates (r=-0.8076, P=0.015), as well as the duodenal ulcer: gastric ulcer ratios (r=-0.9133, P=0.002). Gastric ulcer rates were higher in southern China but did not correlate with the gastric cancer rates (r=0.1455, P=0.731). Duodenal ulcer rates were found to be related to daily rice intake (r=0.8554, P=0.029) and inversely related to daily wheat flour intake (r=-0.8472, P=0.033). Gastric cancer rates were not related to any dietary risk factors tested. We concluded there was an inverse relationship between gastric cancer rates and duodenal ulcer rates. Although duodenal ulceration and gastric cancer are both linked to Helicobacter pylori infection, the findings of this study indicate independent additional aetiological factors for the pathogenesis of these conditions. Dietary factors such as rice or wheat intake may play a role.     

Characteristics of foveating and defoveating fast phases in latent nystagmus

PURPOSE: Under certain conditions, the fast phases of latent/manifest latent nystagmus (LMLN) can defoveate the target of interest instead of foveating it, as was thought to be their only function. LMLN fast phases in the waveforms from four subjects were studied with the goals of better understanding their characteristics and determining what triggers both foveating and defoveating fast phases. METHODS: Eye movement records were made using both the scleral search coil and infrared methods. Relationships of fast-phase sizes with slow-phase positions and velocities before and after fast phases were analyzed, as were relationships of saccade size with peak velocity and duration. RESULTS. The data showed that LMLN with defoveating fast phases occurred in the presence of higher slow-phase velocities. Also, larger saccade sizes corresponded to larger presaccadic and postsaccadic slow-phase velocities. The peak velocities and durations of LMLN fast phases were in the same ranges as normal saccades. CONCLUSIONS: Defoveating fast phases with decreasing-velocity slow phases may be the result of the addition of saccadic pulses to linear slow phases. Mechanisms are suggested to explain the switch from foveating to defoveating fast phases in LMLN.     

Biosynthesis and metabolism of native and oxidized neuropeptide Y in the hippocampal mossy fiber system

Neuropeptide Y (NPY) gene expression is known to be modulated in the mossy fiber projection of hippocampal granule cells following seizure. We investigated NPY biosynthesis and metabolism in an attempt to characterize NPY biochemically as a neurotransmitter in the granule cell mossy fiber projection. NPY biosynthesis was compared in normal control animals and in animals that had experienced a single pentylenetetrazole-induced seizure. In situ hybridization analysis established the postseizure time course of preproNPY mRNA expression in the hippocampal formation, localizing the majority of increased preproNPY mRNA content to the hilus of the dentate gyrus. Radioimmunoassay analysis of the CA3/mossy fiber terminal subfield confirmed a subsequent increase in NPY peptide content. Biosynthesis of NPY peptide by granule cells and transport to the CA3/mossy fiber subfield was demonstrated by in vivo radiolabel infusion to the dentate gyrus/hilus followed by sequential HPLC purification of identified radiolabeled peptide from the CA3/mossy fiber terminal subfield. Additional in vivo radiolabeling studies revealed a postseizure increase in an unidentified NPY-like immunoreactive (NPY-LI) species. HPLC/radioimmunoassay analyses of CA3 subfield tissue extracts comparing normal control animals and pentylenetetrazole-treated animals confirmed the increased total NPY-LI, and demonstrated that the increased NPY-LI was comprised of a minor increase in native NPY and a major increase in the unknown NPY-LI. Data from subsequent and separate analyses incorporating immunoprecipitation with anti-C-terminal flanking peptide of NPY, further HPLC purification, and matrix-assisted laser desorption/ionization mass spectrometry support the conclusion that the unknown NPY-LI is methionine sulfoxide NPY. NPY and NPY-sulfoxide displayed differential calcium sensitivity for release from mossy fiber synaptosomes. Similar to NPY, NPY sulfoxide displayed high-affinity binding to each of the cloned Y1, Y2, Y4, and Y5 receptor subtypes. Postrelease inactivation of NPY was demonstrated in a mossy fiber synaptosomal preparation. Thus, the present study in combination with previously reported electrophysiological activity of NPY in the CA3 subfield demonstrates that NPY fulfills the classical criteria for a neurotransmitter in the hippocampal granule cell mossy fiber projection, and reveals the presence of two molecular forms of NPY that display differential mechanisms of release while maintaining similar receptor potencies.     

Cloning, characterization, and chromosomal localization of human superillin (SVIL)

The specific aim of this study was to determine the response of alveolar bone after it was augmented vertically using distraction osteogenesis and subsequently loaded with implant restorations. Four dogs each had four implants placed horizontally into an edentulous mandibular quadrant and, after integration, a distraction osteogenesis device was fabricated in the laboratory. An osteotomy was made to allow the crest of the alveolar ridge to be distracted vertically. After 10 mm of vertical distraction, the device was stabilized with light cured resin. Following bone fill confirmation of the distraction gap at 10 weeks, two implants were placed into the ridges, one in distracted bone and one in nondistracted bone. After 4 months for implant integration, freestanding prostheses were fabricated. Crestal bone levels were evaluated throughout the period of function. Animals were sacrificed after 1 year of loading, for histologic evaluation of the bone. The vertical ridge augmentation averaged 8.85 +/- 1.05 mm after 10 weeks of healing following distraction, without change over 1 year of implant loading. Histologic examination showed that bone had formed between the distracted segments, creating an augmented ridge. The average thickness of the labial cortex in the distraction gap was significantly thinner than the lingual cortex in distracted bone and the lingual and labial nondistracted cortical bone. The presence of the dental implant did not significantly affect cortical bone thickness. Serial sections showed that implants remained integrated and functional without soft tissue inflammation. Dental implants placed into alveolar ridges augmented with the technique of distraction osteogenesis maintained bone and were functional for the length of this study.