Nitric oxide mediates interleukin-1-induced matrix degradation and basic fibroblast growth factor release in cultured rabbit articular chondrocytes: a possible mechanism of pathological neovascularization in arthritis

Prolonged incubation with interleukin-1 beta (IL-1) induced the release of large amounts of NO and subsequently inhibited DNA synthesis and the biosynthesis and accumulation of proteoglycans in cultured rabbit articular chondrocytes (RAC). IL-1 also inhibited DNA synthesis in bovine aortic endothelial cells (BAE). On the other hand, DNA synthesis in BAE cocultured with RAC was not inhibited by prolonged incubation with IL-1. Moreover, conditioned media from RAC incubated for a long period with IL-1 stimulated DNA synthesis in BAE alone. This growth stimulatory activity was mainly due to the release of basic fibroblast growth factor, a heparin-binding growth factor, into RAC culture. Gelatin zymography of the RAC culture medium revealed that IL-1 increased the production of matrix metalloproteinase-2 (MMP-2) and MMP-9. NG-Monomethyl-L-arginine, an inhibitor of NO synthesis, inhibited all of these actions of IL-1. These results indicate that NO from RAC treated with IL-1 stimulates MMPs, which, in turn, degrade the extracellular matrix produced by RAC, resulting in the release of large amounts of basic fibroblast growth factor stored in the matrix, which then stimulates adjacent BAE proliferation. Thus, NO produced from RAC treated with IL-1 may modulate angiogenesis in the synovium of arthritic patients.

Primary malignant melanoma of the sinonasal cavity: MR imaging evaluation

To evaluate the magnetic resonance (MR) imaging characteristics of primary malignant melanoma of the sinonasal cavity, T1- and T2-weighted MR images of 12 patients with primary sinonasal melanoma were retrospectively reviewed. Gadolinium-enhanced imaging was performed in seven cases. The MR images were compared with histopathologic results. There were seven melanotic melanomas and five amelanotic melanomas; hemorrhage was present in three melanotic and two amelanotic melanomas. The seven melanotic melanomas were hyperintense to gray matter on T1-weighted images (whether hemorrhage was present or not), consistent with the paramagnetic effect of melanin. Four of the five amelanotic melanomas had intermediate signal intensity on T1-weighted images; one was not detected. On T2-weighted images, all of the melanomas detected had intermediate though variable signal intensity compared with that of gray matter. On gadolinium-enhanced images, all cases demonstrated mild to moderate enhancement. The signal intensity of sinonasal melanoma appears to vary according to the histopathologic components of the tumor. High signal intensity within the lesion on T1-weighted images suggests the presence of melanin.

Inositol trisphosphate/Ca2+ as messengers of bradykinin B2 and muscarinic acetylcholine m1-m4 receptors in neuroblastoma-derived hybrid cells

Neuroblastoma x glioma hybrid NG 108-15 and neuroblastoma x fibroblast hybrid NL308 cells possess endogenous bradykinin B2 receptors and m4 muscarinic acetylcholine receptors (mAChRs), which couple to phospholipase C and adenylate cyclase, respectively. Four genetic subtypes of mAChRs differed in their effects when stimulated in NG108-15 and NL308 cells overexpressing mAChRs. Broadly speaking, the principal effects fell into two categories: the odd-numbered receptors (m1 and m3) activated phospholipase C and increased inositol trisphosphate/Ca2+, as bradykinin did, whereas the even-numbered receptors (m2 and m4) inhibited adenylate cyclase via a pertussis toxin (PTx)-sensitive G-protein in NG108-15 cells. But all four types of NL308 cells overexpressing each m1, m2, m3 and m4 receptor activated phospholipase C, while keeping the PTx-sensitivity in m2/m4, but not in m1/m3 receptors. Coupling to ion channel effectors showed a comparable dichotomy in NG108-15 cells, while cross-activation occurred in NL308 cells.

Temperature-sensitive parainfluenza type 1 vaccine virus directly accesses the central nervous system by infecting olfactory neurons

Immunohistochemical investigation showed that intranasal inoculation of mice with a temperature-sensitive (ts) mutant of parainfluenza type 1 vaccine virus resulted in infection of some olfactory neurons as well as respiratory epithelial cells. It also disclosed the presence of viral antigens in glomeruli of the olfactory bulb but not in the secondary neurons (mitral and tufted cells). Polymerase chain reaction demonstrated the persistence of virus-specific nucleic acids in the olfactory bulb. These observations lead to the conclusion that parainfluenza virus, even with a ts phenotype, gains access to the central nervous system by infecting olfactory neurons.

CNS-mediated influence of TRH and its analog, NS-3, on the function of the rabbit lower urinary tract

The effects of thyrotropin-releasing hormone (TRH) and its new analog, NS-3 (montireline), on the lower urinary tract in rabbits were investigated. TRH and NS-3 elicited transient increases in intravesical pressure and micturition. They also caused long-lasting increases in intraurethral pressure and EMG activity of the external urethral sphincter, which were not affected by prazosin or transection of the hypogastric nerve, but were eliminated by transection of the pudendal nerve. In animals decerebrated at the supracollicular post-mammillary level, these drugs did not increase intravesical pressure or micturition, but they did elicit increases in intraurethral pressure and sphincter EMG activity. No binding sites for TRH were found in the lower urinary tract. These findings suggest that the sites of action of TRH and NS-3 which elicit intravesical pressure increase or micturition might be located in the area rostral to the pons, and that the sites of action which elicit increases in intraurethral pressure and sphincter EMG activity might be located caudal to the rostral pons.

Predicting risk of embolization during anticoagulation for left atrial thrombus by transesophageal echocardiography: a case report

A 75-year-old woman was admitted with transient left hemiparesis accompanied by diminished level of consciousness in September 1994. Holter electrocardiography showed transient atrial fibrillation, and transesophageal echocardiography (TEE) revealed an atrial septal aneurysm, spontaneous echo contrast, and a thrombus in the left atrial appendage. The patient received anticoagulant treatment with warfarin, and follow-up TEE showed thrombus resolution. However, after the warfarin was discontinued, symptoms recurred in October 1995 and TEE showed a club-like left atrial thrombus (21 x 40 mm) originating in the left atrial appendage and extending to the center of the left atrium. Follow-up TEE after warfarin therapy showed resolution at the neck of the thrombus but the head threatened detachment. The thrombus was subsequently excised surgically. Follow-up TEE was critical for detecting the risk of significant embolization during anticoagulant therapy.

Expression of cadherin-11 delineates boundaries, neuromeres, and nuclei in the developing mouse brain

Cadherin-11 (cad11 or OB-cadherin) was previously identified as a mesenchymal cell-cell adhesion molecule. Here we studied the expression of cad11 transcripts in developing brains derived from E11.5 to E16.5 mouse embryos. In the brains at these stages, cad11 was expressed in various patterns, which could be grouped into three categories. First, cad11 expression occurred along boundaries between certain brain subdivisions, including those between the ventral and dorsal thalamus and between the mesencephalon and metencephalon. At these boundaries, cad11-positive cells were localized in a narrow, columnar compartment of the neuroepithelium. Second, cad11 expression delineated particular neuromeric compartments at the ventricular zone of the neuroepithelium. A typical example of this pattern was observed in the hypothalamus. Third, cad11 was expressed in differentiating or differentiated brain nuclei. The former included the thalamus, epithalamus, and pretectum; the latter included the mammillary, red, trigeminal motor, facial motor, prepositus hypoglossal, and inferior olive nuclei, as well as the substantia nigra. Furthermore, developing nuclei and the superficial zone of the cerebellum expressed cad11, and the cortical plate of the developing cerebrum also did so. We compared the expression pattern of cad11 with that of R-cadherin in the diencephalon and found that each cadherin delineated a unique set of diencephalic subdivisions. These findings suggest that cad11-mediated specific cell-cell adhesion plays roles in segmentation or compartmentalization of the developing brain in various ways. We also discussed the possibility that cad11 might be involved in neuronal connections between specific nuclei.

Establishment of an experimental liver metastasis model by intraportal injection of a newly derived human pancreatic cancer cell line (KLM-1)

CONCLUSION

It is suggested that this liver metastasis model formed by a highly metastatic variant (KLM-1) is valuable for the study of the liver metastatic processes of human pancreatic cancer.

BACKGROUND

Liver metastasis in the early postoperative period is one of the causes for the poor prognosis of patients with resected pancreatic cancer. Therefore, it is necessary to establish an experimental model to study the mechanisms of liver metastasis in pancreatic cancer.

METHODS

Human pancreatic cancer cell lines (PK-1, PK-9, and KLM-1) were injected into the portal vein of nude mice with or without pretreatment with antiasialo GM1, and colonies of liver metastases were counted for comparison of metastatic ability of these cell lines. Biological and histopathological characteristics of the highly liver metastatic cell line (KLM-1) were compared with its parent cell line (PK-1).

RESULTS

PK-1 cells and PK-9 cells rarely formed liver metastasis foci, but pretreatment with antiasialo GM1 promoted liver metastasis. KLM-1 cells formed liver metastases at the rate of 70% even without antiasialo GM1 pretreatment. KLM-1 cells had such biological characteristics as short doubling time, short lag phase, and resistance to NK cytotoxicity. After intraportal injection of 125I-labeled KLM-1 cells, radioactivity as well as micrometastases were detected in the liver at 72 h.

Natural resistance against tumors grafted into the brain in association with histocompatibility-class-I-antigen expression

The role of MHC-class-I-antigen expression in intracerebral anti-tumor natural resistance was examined using MHC-positive Lym+ and MHC-negative Lym- lymphoma cell lines. Lym+ was sensitive to MHC-class-I-restricted CTL-mediated lysis, while lym- was resistant. Both lines were susceptible to NK-cell-mediated lysis. There was no difference in in vitro growth rate of in vivo intraperitoneal tumorigenicity between them. Inoculation of Lym+ cells into the brain caused upregulation of the intracellular MHC mRNA to the same level as after treatment with interferon-gamma, resulting in an increase in cell-surface MHC expression. Although inoculated Lym- cells also underwent an increase in cytosolic MHC mRNA, the cell-surface MHC expression remained negative. Immunoprecipitation revealed that the terminal glycosylation did not occur normally in Lym-. An in vivo intracerebral tumorigenicity assay, using 2 groups of untreated and NK-cell-depleted syngeneic mice, showed that Lym+ was less tumorigenic than Lym-. In T-cell-depleted mice, however, no difference was detected between them. In addition, when Lym+ and Lym- cells were inoculated into the brain of allogeneic or syngeneic preimmunized mice (immunized with tumor cells), Lym+ was rejected, while Lym- was accepted. When allogeneic mice had received treatment for T-cell depletion before intracerebral inoculation, no rejection was observed in Lym+. On the other hand, Lym- cells, when injected i.p. into NK-depleted mice, had greater killing activity than Lym+ cells, while in T-cell-depleted mice Lym- was less tumorigenic than Lym+. These results suggest that MHC-positive tumor cells grafted into the brain may be rejected by CTL in an MHC-dependent manner, whereas MHC-negative tumor cells can escape from T-cell-mediated immunosurveillance and grow progressively in the brain, due to absence of intracerebral natural resistance mediated by NK cells.

Brain pertussis toxin-sensitive G proteins are involved in the flavoxate hydrochloride-induced suppression of the micturition reflex in rats

The effect of flavoxate hydrochloride (flavoxate), an anti-pollakiurea agent, on cyclic AMP (cAMP) formation was investigated in the rat brain and a possible involvement of brain G proteins in the action of flavoxate on the bladder function was subsequently examined. Flavoxate (10(-8)-10(-5) M) inhibited cAMP formation in a concentration-dependent manner, an action which was completely abolished by pretreating the membranes with pertussis toxin (PTX). The inhibitory effect of flavoxate was also completely antagonized by combined treatment with any two antagonists for adenosine A1 (8-cyclopentyl-1,3-dipropylxanthine), dopamine D2 (sulpiride) or adrenergic alpha 2 (yohimbine) receptors, although each antagonist alone did not significantly block the flavoxate-induced inhibition of cAMP formation. Radioligand binding studies indicated that flavoxate at micro- or submicromolar concentrations has affinity for Gi-coupled receptors such as A1, D2 and alpha 2 receptors. Therefore, flavoxate may inhibit cAMP formation by the stimulation of A1, D2 and alpha 2 receptors. To clarify the involvement of brain Gi proteins in the flavoxate-induced inhibition of the micturition reflex, the effect of pretreatment with PTX (i.c.v.) on the flavoxate-induced inhibition of isovolumetric rhythmic bladder contractions was examined in rats. Flavoxate (3 mg/kg, i.v.) completely abolished rhythmic bladder contractions in vehicle-pretreated rats, but not in PTX-pretreated rats. These findings suggest that signal transduction via Gi-coupled receptors is involved, at least in part, in the inhibition of the micturition reflex by flavoxate in rats. These results also provide the first evidence suggesting a negative role of brain PTX-sensitive G proteins in the micturition reflex.

Effective administration methods and dosages of interferon therapy for chronic hepatitis C

The efficacy of interferon alfa (IFN-alpha) was evaluated in 127 hepatitis C virus-ribonucleic acid (HCV-RNA)-positive patients with chronic hepatitis C in relation to HCV-RNA levels and genotype. Patients were assigned to one of three groups. Patients in group A received IFN-alpha daily for 8 weeks (total dose, 336 million units [MU]); patients in group B received IFN-alpha daily for 4 weeks and then intermittently for 20 weeks (total dose, 348 MU); and patients in group C received IFN-alpha daily for 2 weeks and then intermittently for 22 weeks (total dose, 480 MU). Complete response rates in groups B and C were significantly higher than those in group A, regardless of the virus level or genotype. Complete response rates in groups B and C were similar, but in patients with a high virus level or HCV-RNA genotype II, the partial response rate in group C was significantly higher than that in group B. In conclusion, IFN-alpha was more effective after daily and then intermittent administration than after daily administration only, and a higher daily dose was necessary to be more effective in patients with high virus levels or HCV-RNA genotype II.

Oxidative damage to skeletal muscle DNA from patients with mitochondrial encephalomyopathies

To estimate the oxidative damage to skeletal muscle DNA in mitochondrial encephalomyopathies, we studied the amount of 8-hydroxy-deoxyguanosine (8-OH-dG) and the localization of superoxide dismutase (SOD) in the skeletal muscles of patients with progressive external ophthalmoplegia (PEO) or Kearns-Sayre syndrome (KSS). The molar ratio of 8-OH-dG/deoxyguanosine in skeletal muscle from PEO or KSS patients was significantly higher than the control value. The ratio from patients with polymyositis or Duchenne's muscular dystrophy was not significantly elevated. Immunohistochemical staining for both Mn-SOD and Cu,Zn-SOD showed pronounced staining in the subsarcolemmal and intermyofibrillar regions of cytochrome-oxidase-negative ragged red fibers of KSS or PEO muscles. Our findings suggest that overproduction of 8-OH-dG and mitochondrial dysfunction with gene deletions are associated with each other in muscle cells of patients with PEO or KSS, and that free radicals may play an important role in the pathophysiology of mitochondrial encephalomyopathies.

Clinical dental application of Er:YAG laser for Class V cavity preparation

Following the development of the ruby laser by Maiman in 1960, the Nd:YAG laser, the CO2 laser, the semiconductor laser, the He-Ne laser, excimer lasers, the argon laser, and finally the Er:YAG laser capable of cutting hard tissue easily were developed and have come to be applied clinically. In the present study, the Er:YAG laser emitting at a wavelength of 2.94 microns developed by Luxar was used for the clinical preparation of class V cavities. Parameters of 8 Hz and approx. 250 mJ/pulse maximum output were used for irradiation. Sixty teeth of 40 patients were used in this clinical study. The Er:YAG laser used in this study was found to be a system suitable for clinical application. No adverse reaction was observed in any of the cases. Class V cavity preparation was performed without inducing any pain in 48/60 cases (80%). All of the 12 cases that complained of mild or severe intraoperative pain had previously complained of cervical dentin hypersensibility during the preoperative examination. Cavity preparation was completed with this laser system in 58/60 cases (91.7%). No treatment-related clinical problems were observed during the follow-up period of approx. 30 days after cavity preparation and resin filling. Cavity preparation took between approx. 10 sec and 3 min and was related more or less to cavity size and depth. Overall clinical evaluation showed no safety problem with very good rating in 49 cases (81.7%).

Sperm membrane incorporation into oolemma contributes to the oolemma block to sperm penetration: evidence based on intracytoplasmic sperm injection experiments in the mouse

Mouse oocytes were fertilized by intracytoplasmic sperm injection (ICSI) and reinseminated after the removal of zonae pellucidae at pronuclear stage or at the 2-cell stage. Although these oocytes were activated normally by ICSI, as evidenced by resumption of meiosis and cortical granule exocytosis, they did not develop oolemma block to sperm penetration. They could be penetrated by spermatozoa at pronuclear stage and even at the 2-cell stage. This supports the notion that incorporation of sperm plasma membrane into oolemma contributes to the changes in oolemma that block sperm penetration.

Early recognition of patients with decreased methotrexate clearance following high-dose methotrexate infusion therapy

The purpose of this study was to identify the patients with decreased methotrexate (MTX) clearance as early as possible after the start of high-dose methotrexate (HD-MTX) infusion. Fifty-six patients (age: 18 approximately 83 years) received a HD-MTX infusion (dosage: 1.9 approximately 3.8 g/m2) for 6 h. These patients were retrospectively divided into a low-clearance group and a high-clearance group based on the serum MTX concentration at 48 h (1 microM). Six out of the 56 patients showed decreased MTX clearance. The MTX concentrations in the low-clearance group were significantly higher than those in the high-clearance group even in earlier sampling times than at 48 h. The average MTX concentrations were 330 microM at 6 h, 72 microM at 12 h, and 16 microM at 24 h in the low-clearance group, and those in the high-clearance group were 210 microM, 18 microM, and 1.0 microM, respectively. The estimated elimination half-lives (t1/2) at 6 approximately 12 h and 12 approximately 24 h after the start of the infusion were also significantly longer in the low-clearance group (2.8 vs. 1.7 h and 5.0 vs. 2.8 h, respectively). Therefore, we proposed convenient criteria based on the mean + 1 S.D. of the high-clearance group: the concentration > 270 microM at 6 h and > 32 microM at 12 h; the t1/2 value > 2.1 h at 6-12 h. All 6 patients were recognized as belonging to the low-clearance group at an early stage after HD-MTX infusion by using our proposed criteria. These results indicate that patients with decreased MTX clearance could be identified within the first 12 h after the start of HD-MTX infusion. The factors influencing the prolonged elimination of MTX were also investigated. A significant decrease in renal function on day 2 was observed in the low-clearance group. The MTX level at 12 h and the estimated t1/2 values were significantly correlated with BUN, Scr and Clcr on the 2nd day after HD-MTX therapy, suggesting that an alteration in renal function occurs within 12 h of the HD-MTX infusion. The prolonged elimination of MTX could be attributable to this decrease in renal function.

Mechanisms of the suppression of the bladder activity by flavoxate

BACKGROUND

This study was designed to clarify the primary site of action of flavoxate, clinically used for the treatment of urinary frequency.

METHODS

In rats, the effect of flavoxate on contractile responses in isolated detrusor strips, bladder contraction induced by pelvic nerve stimulation, isovolumetric rhythmic bladder contractions, and pelvic nerve activity were examined. In decerebrated cats, flavoxate was microinjected into the nuclei in the pons, and its effect on reflex micturition was observed.

RESULTS

Flavoxate suppressed carbachol- and calcium ion (Ca2+)-induced contractions of isolated detrusor strips in a noncompetitive and a competitive manner, respectively. Intravenous flavoxate suppressed both initial phasic, and later tonic, bladder contractions induced by electrical stimulation of the distal end of the pelvic nerve. It abolished isovolumetric rhythmic bladder contractions and the associated efferent pelvic nerve activity, without affecting baseline vesical pressure and afferent pelvic nerve activity. When administered intracerebroventricularly or intrathecally, it abolished isovolumetric rhythmic bladder contractions. Flavoxate microinjected into the nucleus reticularis pontis oralis (PoO; pontine micturition inhibitory region) of decerebrated cats inhibited the reflex micturition, but had no effect when microinjected into the locus coeruleus alpha (pontine micturition center) or locus subcoeruleus (pontine urine storage center).

CONCLUSIONS

Flavoxate suppressed the micturition reflex primarily by facilitating the inhibitory action of the PoO on the descending pathways from the pontine micturition center to the sacral parasympathetic intermediolateral nuclei.

Granisetron in the prevention of vomiting induced by conditioning for stem cell transplantation: a prospective randomized study

We conducted a prospective randomized study to compare granisetron, a 5-hydroxytryptamine-3 receptor antagonist with standard anti-emetics (control group) consisting mainly of metoclopramide, in the prophylaxis of emesis induced by conditioning prior to stem cell transplantation. Fifty-eight patients were evaluable for analysis. The number of emetic episodes expressed in terms of patient-days was significantly lower in the granisetron group than in the control group (P < 0.001). During the first 24 h of conditioning, 27 of the 31 patients (87.1%) in the granisetron group achieved control of emesis with less than three emetic episodes (major < or = ) a day compared with 37.0% in the control group (P < 0.001). The same degree of emesis control was maintained throughout the conditioning period in 51.% of patients in the granisetron group compared with 0% in the control group (P < 0.001). Adverse reactions were observed in 11.4% of patients in the granisetron group and in 25.9% in the control group. None of the events were serious. Based on these data, we conclude that granisetron is superior to standard antiemetics in protecting against the vomiting induced by conditioning for stem cell transplantation.

Effects of antihyperlipidemic drugs and diet plus exercise therapy in the treatment of patients with moderate hypercholesterolemia

We compared the efficacy of two antihyperlipidemic drugs and the efficacy of diet plus exercise therapy in the treatment of patients with moderate hypercholesterolemia. The study included 48 patients with moderate hypercholesterolemia (serum total cholesterol [TC], 250 to 320 mg/dL). Patients were divided into three groups: group A--patients administered 10 mg/d of pravastatin; group B--patients administered 500 mg/d of probucol and 600 mg/d of pantethine; and group C--patients administered diet plus exercise therapy. The serum TC and serum high-density lipoprotein cholesterol (HDL-C) values were determined via enzymatic methods before initiation of each therapy and after 4 and 8 weeks of therapy. An atherogenic index (AI) was also calculated. The results indicated that TC showed a statistically significant decrease in all three groups at 4 and 8 weeks (P < 0.001 and P < 0.05, respectively); the HDL-C value did not change significantly in groups A and C, but it had a statistically significant decrease in group B at 4 and 8 weeks. The AI showed a statistically significant decrease in group A at 4 and 8 weeks of treatment and group C at 8 weeks; there were no significant changes in AI in group B. It may be concluded that as an antihyperlipidemic agent, pravastatin is more useful than probucol and that appropriate exercise and strict dietary management for 8 weeks achieve an efficacy close to that achieved by drug therapy.

Oral and maxillofacial radiology teaching file on the World Wide Web

An oral and maxillofacial radiology teaching file on the World Wide Web was created effective June 15, 1995. The file contains 106 cases (279 images) of 94 diseases in the oral and maxillofacial region.