Activation of a chondrocyte volume-sensitive Cl(-) conductance prior to macroscopic cartilage lesion formation in the rabbit knee anterior cruciate ligament transection osteoarthritis model.

OBJECTIVE: The anterior cruciate ligament transection (ACLT) rabbit osteoarthritis (OA) model confers permanent knee instability and induces joint degeneration. The degeneration process is complex, but includes chondrocyte apoptosis and OA-like loss of cartilage integrity. Previously, we reported that activation of a volume-sensitive Cl(-) current (ICl,vol) can mediate cell shrinkage and apoptosis in rabbit articular chondrocytes. Our objective was therefore to investigate whether ICl,vol was activated in the early stages of the rabbit ACLT OA model. DESIGN: Adult Rabbits underwent unilateral ACLT and contralateral arthrotomy (sham) surgery. Rabbits were euthanized at 2 or 4 weeks. Samples were analyzed histologically and with assays of cell volume, apoptosis and electrophysiological characterization of ICl,vol. RESULTS: At 2 and 4 weeks post ACLT cartilage appeared histologically normal, nevertheless cell swelling and caspase 3/7 activity were both significantly increased compared to sham controls. In cell-volume experiments, exposure of chondrocytes to hypotonic solution led to a greater increase in cell size in ACLT compared to controls. Caspase-3/7 activity, an indicator of apoptosis, was elevated in both ACLT 2wk and 4wk. Whole-cell currents were recorded with patch clamp of chondrocytes in iso-osmotic and hypo-osmotic external solutions under conditions where Na(+), K(+) and Ca(2+) currents were minimized. ACLT treatment resulted in a large increase in hypotonic-activated chloride conductance. CONCLUSION: Changes in chondrocyte ion channels take place prior to the onset of apparent cartilage loss in the ACLT rabbit model of OA. Further studies are needed to investigate if pharmacological inhibition of ICl,vol decreases progression of OA in animal models.

Inflammatory pseudotumor of the liver in association with spilled gallstones 3 years after laparoscopic cholecystectomy: report of a case.

We report on a case of a female patient diagnosed with inflammatory pseudotumor of the liver in association with spilled gallstones 3 years after laparoscopic cholecystectomy for calculous acute cholecystitis. She was asymptomatic, but CT revealed an intrahepatic mass and two other extrahepatic masses between the liver and the diaphragm. Furthermore, diffusion-weighted MRI and PET suggested all three lesions could be malignant tumors. As the preoperative diagnosis was intrahepatic cholangiocellular carcinoma with peritoneal disseminations, we performed a posterior segmentectomy of the liver combined with partial resection of the diaphragm. Histological examination showed the intrahepatic tumor was an inflammatory granuloma with abscess formations. There were bilirubin stones between the liver and the diaphragm. Therefore, the tumor was diagnosed as inflammatory pseudotumor of the liver in association with spilled gallstones. In conclusion, the liver tumor emerged after laparoscopic cholecystectomy and may involve inflammatory pseudotumor of the liver in association with spilled gallstones.

Drug delivery observation of hydrophobe ferrofluid and magnetite nanoparticals by SPring-8 synchrotron radiation.

In this study, the composite magnetic nanoparticles of coated SiO nano film with about 8 nm size and high saturation magnetization value, were synthesized by liquid phase precipitation method. The magnetic nanoparticles can be dispersed in various liquid media, widely known as magnetic fluids or ferrofluids with both magnetic and liquid properties. The materials been collected great interests and more and more attentions to focus into Drug Delivery System (DDS) as a new technology in this paper. We use the composite nanoparticles to disperse H2O and inject the solutions into rat's in-vivo organs. And, in the experiments by using a strong photon beam of SPring-8 Synchrotron Radiation facility, the distribution stat and the effects of magnetic field as well as drug delivery behaviour of nanoparticles in the rat' kidney are verified by the in-vivo observations.

Pathological fracture of the mandible resulting from osteomyelitis successfully treated with only intermaxillary elastic guiding.

Treatment of mandibular pathological fractures differs according to etiology. Closed reduction with intermaxillary fixation is usually performed when fractures occur as a result of osteomyelitis. Here is reported a case of pathological fracture of the mandible resulting from osteomyelitis that was successfully treated with intermaxillary elastics only.

Presence of perivenular elastic fibers in nonalcoholic steatohepatitis Fibrosis Stage III.

Elastic fibers appear in extensive old fibrotic foci in general. We examined an association between hepatic fibrosis stage and the presence of perivenular elastic fibers in nonalcoholic steatohepatitis (NASH). A total of 48 liver needle biopsy specimens were used, taken from 48 cases with NASH. Fibrosis Stage (Brunt E, et al. Am. J. Gastroenterol. 1999) of the cases was as follows; six Fibrosis Stage I, twenty-two Fibrosis Stage II, and twenty Fibrosis Stage III. We examined Orcein stain sections in all of the liver needle biopsy specimens. In all twenty Fibrosis Stage III cases, perivenular elastic fiber bundles were observed. In contrast, perivenular elastic fibers were detected only in one of the six Fibrosis Stage I and two of the twenty-two Fibrosis Stage II cases. In liver needle biopsy specimens of NASH, detection of perivenular elastic fibers is useful in deciding Fibrosis Stage III.

The role of muscle grafts in temporomandibular joint ankylosis: short-term experimental study in sheep.

The temporalis muscle flap can be used as an inter-positional graft placed into a gap arthroplasty site in temporomandibular joint (TMJ) ankylosis. The purpose of this study was to investigate the role of the muscle graft in sheep. Five pure-bred adult Merino sheep were used and ankylosis was induced in all right TMJs. At 3 months, the ankylosis was released by gap arthroplasty and reconstructed with a masseter muscle graft, because the temporalis muscle is short and poorly vasculized in sheep. The sheep were killed at 3 months after muscle grafting. The maximal mouth opening was recorded before and after operation and at death. The joints were examined radiologically and histologically. In 4 sheep mouth opening remained at the pre-operative level. A clear radiolucent space remained between the smooth temporal and ramus stumps. Histologically, the muscle graft remained vital but with some fibrous tissue formation between the bone ends. One sheep developed an infection at the operative site following the muscle graft; this partly resolved with antibiotics, but the TMJ developed a fibrous reankylosis that was demonstrated clinically, radiologically and histologically. These results indicate that an uncomplicated temporalis muscle graft reconstruction with gap arthroplasty is a successful and stable procedure in human TMJ ankylosis.

Cystadenoma of the liver with ovarian-like stroma: case report.

Cystadenomas are rare benign tumors with malignant potential. A 36-year-old woman presented with a 20-cm cystic mass in the left lobe of the liver. Surgery confirmed the diagnostic imaging findings. We present a case of cystadenoma of the liver with ovarian-like stroma and its associated radiologic characteristics.

The expression of nectin-1alpha in normal human skin and various skin tumours.

BACKGROUND: A novel cell-cell adhesion system that consists of nectin and afadin has been identified at cadherin-based cell-cell adherens junctions. Nectin is a Ca2+-independent homophilic and heterophilic cell adhesion molecule that belongs to the immunoglobulin superfamily. Nectin has recently been shown to serve as an alpha-herpesvirus entry and cell-cell spread mediator. In spite of the ubiquitous expression of nectin-1alpha, its detailed localization in human skin has not been examined so far. OBJECTIVES: To investigate the localization of nectin-1alpha in normal human skin and the alteration of its expression in malignant skin tumours. METHODS: Immunohistochemistry was employed to determine the expression of nectin-1alpha and other adhesion molecules. RESULTS: We detected nectin-1alpha in normal human epidermis, follicles and eccrine ducts. Nectin-1alpha was colocalized with E-cadherin at cell-cell adherens junctions of the epidermis. The concentration of the nectin-afadin system at cell-cell adherens junctions was reduced in the early stage of malignant transformation of keratinocytes, such as in basal cell carcinomas and squamous cell carcinomas, where the cadherin-catenin system was preserved. Nectin-1alpha at cell-cell adherens junctions was reduced in human epithelial cancer cells located at the advancing border of the tumour. CONCLUSIONS: Our results showed that nectin-1alpha is located at cell-cell adherens junctions in human skin and that reduction of nectin-1alpha at cell-cell adherens junctions may be involved in the invasion of squamous cell tumours.

Washout studies of 11C in rabbit thigh muscle implanted by secondary beams of HIMAC.

Heavy ion therapy has two definite advantages: good dose localization and higher biological effect. Range calculation of the heavy ions is an important factor in treatment planning. X-ray CT numbers are used to estimate the heavy ion range by looking up values in a conversion table which relates empirically photon attenuation in tissues to particle stopping power; this is one source of uncertainty in the treatment planning. Use of positron emitting radioactive beams along with a positron emission tomograph or a positron camera gives range information and may be used as a means of checking in heavy ion treatment planning. However, the metabolism of the implanted positron emitters in a living object is unpredictable because the chemical forms of these emitters are unknown and the metabolism is dependent on the organ species and may be influenced by many factors such as blood flow rate and fluid components present. In this paper, the washout rate of 11C activity implanted by injecting energetic 11C beams into thigh muscle of a rear leg of a rabbit is presented. The washout was found to consist of two components, the shorter one was about 4.2 +/- 1.1 min and the longer one ranged from 91 to 124 min. About one third of the implanted beta+ activity can be used for imaging and the rest was washed out of the target area.

Regeneration of the mandibular condyle after unilateral condylectomy and myotomy of the masseter in lambs.

We investigated the degree of regeneration of the mandibular condyle after unilateral condylectomy and myotomy of the masseter in growing lambs. Four 10-week-old lambs had unilateral condylectomy and myotomy of the superficial layer of the masseter on the right side, and were killed 3 months later. The joints were examined radiologically and histologically. All joints showed poor regeneration of the condylar head. In the medial plane there was partial condylar and articular cartilage reformation, but in the lateral plane there was neither condylar nor cartilaginous reformation. The articular cartilage of the temporal bone was thicker in the medial plane and the disc was thicker in the central plane, than in unoperated joints. We conclude that unilateral condylectomy and myotomy of the masseter in the growing period results in poor regeneration of the condyle.

Increase in intracellular Ca(2+) and calcitonin gene-related peptide release through metabotropic P2Y receptors in rat dorsal root ganglion neurons.

We examined the effects of the activation of metabotropic P2Y receptors on the intracellular Ca(2+) concentration and the release of neuropeptide calcitonin gene-related peptide (CGRP) in isolated adult rat dorsal root ganglion neurons. In small-sized dorsal root ganglion neurons (soma diameter<30 microm) loaded with fura-2, a bath application of ATP (100 microM) evoked an increase in intracellular Ca(2+) concentration, while the removal of extracellular Ca(2+) partly depressed the response to ATP, thus suggesting that the ATP-induced increase in intracellular Ca(2+) concentration is due to both the release of Ca(2+) from intracellular stores and the influx of extracellular Ca(2+). Bath application of uridine 5'-triphosphate (UTP; 100 microM) also caused an increase in intracellular Ca(2+) concentration in small-sized dorsal root ganglion neurons and the P2 receptor antagonists suramin (100 microM) and pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid (PPADS; 10 microM) virtually abolished the response, indicating that the intracellular Ca(2+) elevation in response to UTP is mediated through metabotropic P2Y receptors. This intracellular Ca(2+) increase was abolished by pretreating the neurons with thapsigargin (100 nM), suggesting that the UTP-induced increase in intracellular Ca(2+) is primarily due to the release of Ca(2+) from endoplasmic reticulum Ca(2+) stores. An enzyme-linked immunosorbent assay showed that an application of UTP (100 microM) significantly stimulated the release of CGRP and that suramin (100 microM) totally abolished the response, suggesting that P2Y receptor-mediated increase in intracellular Ca(2+) is accompanied by CGRP release from dorsal root ganglion neurons. These results suggest that metabotropic P2Y receptors contribute to extracellular ATP-induced increase in intracellular Ca(2+) concentration and subsequent release of neuropeptide CGRP in rat dorsal root ganglion neurons.

[Effects of long-term treatment with prostacyclin on plasma adrenomedullin in patients with primary pulmonary hypertension].

OBJECTIVES: This study investigated whether plasma levels of adrenomedullin, a potent vasodilating endogenous neurohumoral mediator, are useful for assessing the severity of primary pulmonary hypertension. METHODS: Seventeen pediatric patients with primary pulmonary hypertension (eight girls, nine boys, mean age 12 +/- 4 years) were enrolled in this study. Thirteen patients in New York Heart Association (NYHA) classes III and IV had been treated with long-term continuous intravenous prostacyclin (PGI2) infusion therapy, and four patients in classes I and II had received beraprost sodium, an oral PGI2 analogue. Blood samples were taken from all patients at the first visit. Plasma levels of atrial and brain natriuretic peptide (ANP, BNP) and endothelin-1, and mature-type adrenomedullin were measured. The relationships were investigated between neurohumoral mediator levels and NYHA class, pulmonary hemodynamics, and exercise capacity assessed by 6-minute walk test. The changes in neurohumoral mediator levels at 1 month, 3 months, and 6 to 12 months were also evaluated in 11 survivors with long-term PGI2 treatment. RESULTS: All neurohumoral mediator levels were positively correlated with severity of NYHA class. Patients in class IV demonstrated significantly elevated neurohumoral mediator levels, except endothelin-1, in comparison with patients in classes I-III. Neurohumoral mediator levels had a significant negative correlation with exercise capacity. Stepwise regression analysis revealed that the BNP to ANP ratio (BNP/ANP) was the most powerful independent factor for total pulmonary resistance (r = 0.85, p = 0.0071) and cardiac index (r = 0.84, p = 0.009). Adrenomedullin was significantly correlated with BNP (r = 0.53, p = 0.03), endothelin-1 (r = 0.66, p = 0.006), and BNP/ANP (r = 0.73, p = 0.0009). ANP and BNP decreased from 196 +/- 213 and 494 +/- 361 pg/ml at baseline to 74 +/- 47 and 153 +/- 133 pg/ml at 1 month, respectively. There was an apparent re-increase in both ANP (187 +/- 194 pg/ml) and BNP (466 +/- 621 pg/ml) at 3 months, regardless of improvement in NYHA class and exercise capacity after long-term PGI2 treatment. In contrast, adrenomedullin decreased from 3.0 +/- 2.2 (baseline) to 1.7 +/- 0.7 fmol/ml at 1 month and 1.6 +/- 0.5 fmol/ml at 3 months. Adrenomedullin was slightly increased at 6-12 months (2.1 +/- 0.9 fmol/ml) without statistical significance. There was a significant relationship between the changes in adrenomedullin at 3 months compared to values at initiation of PGI2 therapy and the changes in mean pulmonary arterial pressure (r = 0.97, p = 0.0041). CONCLUSIONS: Plasma levels of neurohumoral mediators are useful for assessing the severity of primary pulmonary hypertension. In particular, adrenomedullin was valuable for evaluating both cardiac performance and pulmonary hemodynamics after long-term treatment with PGI2 in patients with primary pulmonary hypertension.

Changes in the pattern of horseradish peroxidase diffusion into predentin and dentin after cavity preparation in rat molars.

OBJECTIVE: The purpose of this study was to examine the process of reducing dentin permeability in adult rat molars after cavity preparation with horseradish peroxidase as a tracer. STUDY DESIGN: Class V cavities were prepared on the upper first molars of 18 rats. Horseradish peroxidase was injected into the vascular system at intervals of 3 hours and 3, 5, 7, 10, and 14 days after cavity preparation, and frozen sections were processed by the diaminobenzidine procedure. RESULTS: Horseradish peroxidase reaction products were noted in the dentinal tubules immediately beneath the cavity up until 14 days after cavity preparation. An abrupt stoppage of reactive products caused by impermeable junctional zone formation at the interface of the primary dentin and reparative dentin was observed at 14 days after cavity preparation. CONCLUSION: Reparative dentin formation and subsequent impermeable junctional zone formation participate in the reduction of dentin permeability after cavity preparation.

Negative feedback regulation of ASK1 by protein phosphatase 5 (PP5) in response to oxidative stress.

Apoptosis signal-regulating kinase 1 (ASK1) is a MAP kinase kinase kinase (MAPKKK) that activates the JNK and p38 MAP kinase cascades and is activated in response to oxidative stress such as hydrogen peroxide (H(2)O(2)). A yeast two-hybrid screening identified a serine/threonine protein phosphatase 5 (PP5) as a binding partner of ASK1. PP5 directly dephosphorylated an essential phospho-threonine residue within the kinase domain of ASK1 and thereby inactivated ASK1 activity in vitro and in vivo. The interaction between PP5 and ASK1 was induced by H(2)O(2) treatment and was followed by the decrease in ASK1 activity. PP5 inhibited not only H(2)O(2)-induced sustained activation of ASK1 but also ASK1-dependent apoptosis. Thus, PP5 appears to act as a physiological inhibitor of ASK1-JNK/p38 pathways by negative feedback.

The effect of gap arthroplasty on temporomandibular joint ankylosis: an experimental study.

The aim of this study was to demonstrate the functional and anatomical changes after gap arthroplasty release of unilateral temporomandibular joint (TMJ) ankylosis. Five adult sheep weighing an average of 57 kg were used. All right joints were operated. Ankylosis was induced in the right TMJ by articular damage, disk removal and placement of a bone graft plus immobilization wire. At 3 months the gap arthroplasty were performed. All TMJs were examined functionally, radiologically, macroscopically and histologically. Functionally, the range of jaw movements decreased following induction of ankylosis (P<0.0001), increased immediately on release but was reduced again at 3 months after release (the vertical movement, no statistically significant difference; the right movement, P<0.001; the left movement, P<0.0001). Histologically, all operated joints showed fibrous adhesions across the gap, and further, the articular surface was irregular with osteophytes and with bony islands in the gap. This appearance is more consistent with a fibrous reankylosis than a functioning pseudo joint. This study shows that the gap arthroplasty for TMJ ankylosis did not restore the TMJ functionally and histologically to the preexisting state.