P-glycoprotein expression in soft-tissue sarcomas

Multidrug resistance (MDR) is an important problem in chemotheraphy for neoplastic disease. In humans, MDR is mainly mediated by P-glycoprotein (P-gp), a product of theMDR1 gene, which acts as a transmembrane protein pump and eliminates chemotherapeutic agents from the cells. Expression of P-gp was immunohistochemically studied by using two monoclonal antibodies, JSB-1 and C-219, on paraffin-embedded sections from 55 patients with soft-tissue sarcoma. The histological diagnosis of tumors was malignant fibrous histiocytoma in 24 cases, liposarcoma in 9, synovial sarcoma in 7, malignant neurogenic tumors in 6, leiomyosarcoma in 5, others in 4. The histological grade was determined on the basis of criteria previously proposed by us. Out of 55 cases, 34 (62%) were positive for P-gp expression. There was a significant difference in P-gp expression between high-grade (90%) and intermediate and low-grade tumors (46%) (P<0.005). Tumors expressing P-gp had a less favorable prognosis than P-gp-negative tumors in the high- and intermediate-grade tumors. The current study demonstrated that the estimation of P-gp expression could be used to select appropriate therapeutic modalities.Abbreviations MDR multidrug resistance - P-gp P-glyco-protein     

Intraocular penetration kinetics of prednisolone after subconjunctival injection in rabbits

Prednisolone concentrations in cornea, aqueous humor, and vitreous humor and the residual amount in conjunctival tissue were assayed by high-performance liquid chromatography during a 14-hour period after subconjunctival injection of prednisolone sodium succinate in rabbits. Prednisolone was concentrated in the corneal epithelium and reached a peak within 5 min, whereas the peak level of prednisolone in stroma-endothelium was achieved 1 h after the injection. There was an apparent linear binding of prednisolone with the ocular tissue homogenates and fluids except for the vitreous humor. However, the protein binding of prednisolone with vitreous humor showed marked concentration dependency. A pharmacokinetic model involving a rapid conversion to prednisolone from its ester prodrug, first-order transfer to various tissues, and first-order elimination of unbound prednisolone from vitreous humor succeeded in predicting the observed concentration-time profiles of prednisolone in various ocular tissues and fluids after subconjunctival injection at three different doses: 0.1, 1.0, and 10.0 mg/kg. The present model predicted that absorption into precorneal area and epithelium and direct penetration into aqueous humor and vitreous humor are 1.7, 0.1, and 0.2% of the applied dose, respectively, and that almost the entire dose (98%) is absorbed into the systemic circulation, with a half-life of 38 min.     

Substance P- and calcitonin gene-related peptide-immunofluorescent nerves in the repair of experimental bone defects

Summary Healing of an experimental bony defect in the rat's tibia was studied with an immunofluorescent technique to clarify when and where substance P (SP) and calcitonin gene-related peptide (CGRP) would develop. The normal tibia showed a few SP- and CGRP-immunofluorescent nerve fibres. In the experimental tibia, the number of these fibres increased on the 6th day after operation, reached a peak of proliferation on the 15th day and reverted to normal after the 24th day. The changes were associated with the development and decay of callus tissue suggesting that harmful stimuli from the injured site in a bone could be mediated by sensory nerves throughout the repair period. Most of the SP- and CGRP-immunofluorescence was seen near the vessels, frequently in the same nerve fibres. The SP- and CGRP-immunofluorescent nerves seemed to take part jointly in callus formation through the enhancement of local blood flow.

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Résumé Le procesus de guérison d'une perte de substance osseuse expérimentale a été étudié sur le tibia du rat par immunofluorescence afin de déterminer quand et où la substance P (SP) et la calcitonine peptide d'origine génique (CGRP) se développeraient. Le tibia normal ne montre qu'un petit nombre de fibres nerveuses immunofluorescentes SP et CGRP. Dans le tibia d'expérimentation, les fibres nerveuses immunofluorescentes SP et CGRP augmentent en nombre à partir du 6ème jour, atteignent leur maximum de prolifération le 15ème jour et reviennent à l'état normal après le 24ème jour post-opératoire. Ces modifications sont étroitement associées au développement et à la disparition du cal, suggérant ainsi que les stimuli nocifs provenant de la lésion osseuse pourraient être inactivés par les nerfs sensitifs durant la période de réparation. En outre, la plus grande partie de l'immunofluorescence SP et CGRP a été observée à proximité des vaisseaux, souvent dans les mêmes fibres nerveuses. Il semble que les nerfs immunofluorescents SP et CGRP participent conjointement à la formation du cal en augmentant la vascularisation locale.

     

Reduced Expression of nm23 Is Associated with Metastasis of Human Gastric Carcinomas

Reduced expression of nm23 gene is implicated in high metastatic potential In a variety of malignancies. To elucidate the role of nm23 in human gastric carcinomas, we examined loss of heterozygosity (LOH) of nm23 gene by Southern blotting, nm23 mRNA expression by Northern blotting and nm23 protein expression by Western blotting as well as immunohistochemistry in both primary and metastatic tumors. LOH of nm23 gene was found in 2 (8%) out of the 23 informative gastric carcinomas. Twenty-two (84%) out of the 26 cases expressed nm23 mRNA at higher levels in primary tumor tissue than in corresponding non-neoplastic mucosa. No obvious correlation was observed between clinico-pathological features and LOH of nm23 gene or nm23 mRNA expression. On the other hand, 52% of the gastric carcinomas showed reduction of nm23 immunoreactivity in the metastatic tumor of regional lymph nodes, as compared to the primary tumor. Interestingly, 71% of the gastric carcinomas showed weaker nm23 immunoreactivity in the liver metastasis than in the primary tumor. These results suggest that nm23 overexpression is linked with development of gastric carcinomas and the decrease in expression of nm23 participates in metastasis.     

Two-level posterior lumbar interbody fusion for degenerative disc disease: improved clinical outcome with restoration of lumbar lordosis

BACKGROUND CONTEXT: Although posterior lumbar interbody fusion (PLIF) for degenerative lumbar diseases is routine, there are few reports on double-level PLIF. PURPOSE: To evaluate the clinical outcomes of double-level PLIF. STUDY DESIGN/SETTING: A retrospective study of operated cases in Gifu, Japan. PATIENT SAMPLE: Nineteen patients (8 men and 11 women, 59.5+/-10.2 years) who underwent double-level PLIF between 1996 and 2001. OUTCOME MEASURES: Operation time, blood loss, complications, the Japanese Orthopaedic Association (JOA) score for back pain and lumbar sagittal alignment were evaluated. METHODS: Patients were examined retrospectively at follow-ups of 3.6+/-1.7 years. Primary diseases were spondylolisthesis, spinal canal stenosis, degenerative scoliosis and herniated intervertebral disc. Fusion areas were L3 to L5 in 15 cases and L4 to S1 in 4 cases. RESULTS: The mean JOA score increased from an initial score of 12.9+/-3.5 to 21.3+/-4.9 at the final follow-up. There was a positive correlation (R=0.718, p<.001) between the increase in lordotic angle and the increase in the JOA score. Several parameters suggested that the surgical invasiveness was not minimal. CONCLUSION: Double-level PLIF provided satisfactory results and preserved lumbar spine lordosis.     

The effects of chymase on matrix metalloproteinase-2 activation in neointimal hyperplasia after balloon injury in dogs.

Chymase is known to generate angiotensin II in the vascular wall. In this study we investigated a novel role for chymase other than angiotensin II production in vascular proliferation after balloon injury. Chymase promoted the migration of vascular smooth muscle cells in the matrix-coated invasion chambers and activated promatrix metalloproteinase-2 obtained from the culture medium of vascular smooth muscle cells. Two weeks after balloon injury, significant neointimal formation was found in dog carotid arteries. After injury, active matrix metalloproteinase-2 was increased in parallel with the augmentation of chymase activity that was seen in the proliferating region of the vascular wall. The oral administration of NK3201 (1 mg/kg per day), a chymase inhibitor, prevented neointimal formation and significantly suppressed both active matrix metalloproteinase-2 and chymase activities 2 weeks after injury. These results suggest that chymase inhibitors can prevent the development of intimal hyperplasia via the inhibition of matrix metalloproteinase-2 activation in balloon-injured arteries.     

A pH-sensitive microsphere system for the colon delivery of tacrolimus containing nanoparticles.

Nanoparticles (NP) are known to accumulate at the site of inflammation in inflammatory bowel disease. In order to avoid premature uptake or degradation of NP during their passage through the small intestine, it appeared necessary to devise a form of local delivery system for NP. Tacrolimus (FK506) loaded poly(lactic-co-glycolic acid) NP entrapped into pH-sensitive microspheres (NPMS) were designed to achieve greater selectivity to their site of action when administered orally. The therapeutic efficacy of this drug delivery system was tested in an experimental colitis in rats. The in vitro characterization showed a successful incorporation of FK506-NP and strongly pH-sensitive release kinetics of both NP and drug. During the in vivo studies, clinical activity, colon/body weight index, and myeloperoxidase activity were determined to assess the severity of inflammation. Systemic availability of a fluorescent dye entrapped in the microspheres was measured in order to determine possible adverse effects. The NPMS as well as the controls of NP and MS formulations exhibited significant mitigating effects in the clinical activity index after 3 days of treatment with similar levels for the various therapies. When observing colon/body weight index and myeloperoxidase activity, only the NPMS group reached statistically significant differences (P<0.05) compared to the colitis control group while other groups did not (colitis control: 21.94+/-4.97; FK506 solution: 15.81+/-3.42; FK506-NP: 17.03+/-5.52; FK506-MS: 15.17+/-7.81; and FK-NPMS: 10.26+/-7.76 U/mg tissue). Moreover, the NPMS system reduced the systemic absorption of the entrapped dye compared to the dye solution or simple NP formulation (relative biovailability-solution: 100+/-14.9%; NP: 46.8+/-8.6%; and NPMS: 29.4+/-3.3%). The results suggest that the NPMS system can provide selective delivery of NP in the colon and develop a significant mitigating effect, while the control group treatments appeared to be insufficient.     

Prefrontal cerebral activity during a simple “rock, paper, scissors” task measured by the noninvasive near-infrared spectroscopy method

We conducted a noninvasive near-infrared spectroscopy (NIRS) study using the game of rock, paper, scissors (RPS) as a simple neurocognitive task for the prefrontal cortex (PFC) in 15 healthy volunteers. We employed an opposite “to lose” RPS task coupled with a normal “to win” RPS task, since the former requires inhibition of behavior, one of the most important functions of the prefrontal cortex. During the NIRS examination, subjects had to present one of the three RPS hands in response to hands displayed randomly on a computer screen every 1.5 s, and were required to show hands that lose to the computer, or that beat the computer. We measured the relative concentrations of oxyhemoglobin (oxy-Hb) using the prefrontal probes of the NIRS system during the tasks. The increases in oxy-Hb during the “to win” RPS task were small, but were quite large and laterally dominant during the “to lose” RPS task. The difference between the two tasks might have been due to the participants’ cognitive conflict with losing on the RPS. We conclude that losing is better than winning on the RPS as a sensitive indicator in the NIRS examination of PFC.     

Long-term results of open reduction for residual subluxation in congenital dislocation of the hip: A new open reduction method involving 360° circumferential capsulotomy

We report satisfactory results with a new operative treatment, conducted via an extensive anterolateral approach, involving 360 degree circumferential capsulotomy, for residual subluxation in congenital dislocation of the hip (CDH). Long-term radiographic results of this procedure (group A) were compared retrospectively with the results of partial capsulotomy (group B), which preserved the posteroinferior joint capsule. The mean center edge angle in group A (22.5°) was greater than that in group B (16.0°). Satisfactory results were achieved in 11 of 15 hips (73%) (Severin class I or II) in group A, and in 5 of 12 hips (42%) in group B. These results suggest that whole circumferential capsulotomy can remove obstacles to complete reduction, and that acetabular development can be expected in hips reduced by the procedure, without the performance of innominate osteotomy. We believe that our technique is a useful alternative for the treatment of residual subluxation in CDH.     

Response of Müller cells following experimental lensectomy-vitrectomy

We used morphological, biochemical and immunohistochemical methods to assess the response of Müller cells after experimental lensectomy-vitrectomy in rabbits. We observed widened intercellular spaces between the Müller cells and nerve fibers of ganglion cells, and increased electron opacity in the Müller cells of eyes injected with silicone oil. No apparent morphological changes were detected in the Müller cells of air-injected eyes. The specific and total activities of Müller cell-marker enzymes (glucose 6-phosphatase and glutamine synthetase) showed an initial increase, followed by a decrease. Glial fibrillary acidic protein immunoreactivity was not found in the Müller cells of the normal rabbit retina but was exhibited after surgery. Our results showed that markers of Müller cells associated with glycogenolysis and/or gluconeogenesis, glutamate-glutamine cycle and cytoskeletal protein metabolism were affected by the experimental lensectomy-vitrectomy.