Evaluation of changes of cell-surface thiols as a new biomarker for in vitro sensitization test

In order to find a novel biomarker for a simple assay to predict skin sensitization, we evaluated cell-surface thiols as a biomarker reflecting intracellular signaling in THP-1 cells (human monocytic cell line). First, we found that a decrease of cell-surface thiols on hapten-treated THP-1 cells was induced in parallel with phosphorylation of p38 MAPK. Next, we confirmed that 2-mercaptoethanol in the culture medium and the differentiation state of THP-1 cells did not affect the changes of cell-surface thiols by hapten. Changes of cell-surface thiols on THP-1 cells were detected after 2 h treatment with most allergens (e.g., DNCB, NiSO₄), as well as some non-allergens (e.g., Tween80, benzalkonium chloride), though other non-allergens (e.g., SDS, glycerol) had no effect. When either a significant decrease or increase of cell-surface thiols (more than 15% in each case) was used as a criterion, the results using 36 allergens and 16 non-allergens were in good accordance with those of in vivo assays. Finally, we confirmed that ATP, which is released as a consequence of cytotoxicity, did not affect the changes of cell-surface thiols. Our results suggest that changes of cell-surface thiols may be useful for an in vitro sensitization assay, which we designate as the SH test.     

Functional MRI study of brain activation alterations in patients with obsessive-compulsive disorder after symptom improvement

Dysfunction of the frontal-subcortical circuits has been the most common finding in the pathophysiology of obsessive-compulsive disorder (OCD), and recent neuropsychological studies have shown cognitive impairments in OCD. To clarify the pathophysiology of OCD without the confounding effects of medication, we investigated the alterations of brain function in OCD patients and changes after clinical improvement due solely to behavior therapy. The participants were 11 outpatients with OCD and 19 normal controls. The patients received 12 weeks of behavior therapy. We investigated the differences in the behavioral performance and functional magnetic resonance imaging results during the Stroop test in the patients and normal controls, and their changes after treatment in the patients. The patients showed less activation in the anterior cingulate gyrus and cerebellum than control subjects. Following significant improvement in OC symptoms, the cerebellum and parietal lobe showed increased activation, and the orbitofrontal cortex, middle frontal gyrus, and temporal regions showed decreased activation during the Stroop task, and performance of the task itself improved. Our findings suggest that dysfunction of the posterior brain regions, especially the cerebellum, is involved in the pathogenesis of OCD, and that normalization in function can occur with improvement of OC symptoms.     

Endocardial endothelium-dependent positive inotropy by Ca2+ pump inhibitors: possible involvement of store-operated Ca2+ entry

Positive inotropy by sarcoplasmic/endoplasmic reticulum Ca(2+) pump inhibitors was found and its mechanisms were analyzed pharmacologically. Thapsigargin and cyclopiazonic acid produced positive inotropy in isolated mouse left atria. The responses were inhibited by pretreatment of the endocardial surface with Triton X-100 or by indomethacin, which suggests that the inotropic responses were mediated by prostaglandin(s) released from the endocardial endothelium as well as acetylcholine-induced positive inotropy. The thapsigargin- and acetylcholine-induced positive inotropy was significantly inhibited by Gd(3+), La(3+) and lavendustin A, a tyrosine kinase inhibitor, but not by Ni(2+) and LOE908, a non-selective cation channel inhibitor. Gd(3+) and lavendustin A had no effect on the exogenously applied PGF(2)alpha-induced positive inotropy. In addition, acetylcholine did not induce any positive inotropy when applied after the application of thapsigargin. These results strongly suggest that thapsigargin- as well as acetylcholine-induced prostaglandin release from endocardial endothelium is mediated by store-operated Ca(2+) entry through Gd(3+)-sensitive channels and activation of tyrosine kinase.     

Flavonoids from Acacia pennata and their cyclooxygenase (COX-1 and COX-2) inhibitory activities

Two new flavonoids quercetin 4'-O-alpha-L-rhamnopyranosyl-3-O-beta-D-allopyranoside (1) and apigenin 6-C-[2'-O-(E)-feruloyl- beta-D-glucopyranosyl]-8-C-beta-glucopyranoside (2), along with the known isorhamnetin 3-O-alpha-L-rhamnopyranoside (3), kaempferol 3-O-alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranoside (4), and isovitexin (5) were isolated from the leaves of Acacia pennata Willd. (Mimosaceae) and tested for their anti-inflammatory activity. Their structures were determined by 1D and 2D NMR and mass spectrometry. They were tested for an inhibitory effect on COX-1 and COX-2, showing 60-90% inhibition at 10(-4) g/mL and 5-14% inhibition at 10(-4) g/mL, respectively.     

Role of human SII cortices in sensorimotor integration.

OBJECTIVES: To elucidate the functional properties of neurons in the human primary (SI) and ipsilateral and contralateral secondary (iSII or cSII) cortices in response to stimuli during finger movement.METHODS: We measured somatosensory evoked fields (SEFs) produced by electric stimuli delivered to the median nerve at 0.2 Hz in 6 healthy subjects.RESULTS: The amplitudes of evoked fields from both iSII and cSII were gradually attenuated with time. Consecutive blocks of trials were obtained to assess the habituation of each evoked field. Complex finger movements with attention (gating session) increased the amplitude of evoked fields from the iSII cortices but reduced the amplitudes of evoked fields from the cSII cortices (P<0.01). In contrast, the amplitude of P30 m from the SI did not show habituation effects but decreased significantly in the gating session (P<0.01).CONCLUSIONS: The enhanced iSII as well as suppressed cSII cortices during complex finger movements with attention are not only considered to be result of gating effect but also attention.     

The effect of atypical antipsychotics, perospirone, ziprasidone and quetiapine on microglial activation induced by interferon-gamma

An accumulating body of evidences point to the significance of neuroinflammation and immunogenetics in schizophrenia, characterized by increased serum concentration of several pro-inflammatory cytokines. In the central nervous system (CNS), the microglial cells are the major immunocompetent cells which release pro-inflammatory cytokines, nitric oxide (NO) and reactive oxygen species to mediate the inflammatory process. In the present study, we investigated whether or not atypical antipsychotics, namely perospirone, quetiapine and ziprasidone, would have anti-inflammatory effects on the activated microglia which may potentiate neuroprotection. All three atypical antipsychotics significantly inhibited NO generation from activated microglia while perospirone and quetiapine significantly inhibited the TNF-alpha release from activated microglia. Antipsychotics, especially perospirone and quetiapine may have an anti-inflammatory effect via the inhibition of microglial activation, which is not only directly toxic to neurons but also has an inhibitory effect on neurogenesis and oligodendrogenesis, both of which have been reported to play a crucial role in the pathology of schizophrenia.     

Are patients after severe injury who drop out of a longitudinal study at high risk of mental disorder?

In longitudinal studies of traumatic stress, it is particularly important to examine the data for any differences between those who drop out and those who continue to participate, because reluctance to participate might reflect symptoms of avoidance frequently seen in posttraumatic stress disorder (PTSD). However, whether those who drop out are at high risk of PTSD remains unclear. Over a 25-month period, 188 consecutive patients with motor vehicle accident (MVA)–related injuries admitted emergently were enrolled and followed for 4 to 6 weeks. Baseline characteristics were compared between subjects who did and did not participate in the follow-up study. At 4 to 6 weeks, 66 (35.1%) of the participants had dropped out. Bivariate analyses revealed that those who dropped out were likely to be men, alcohol drinkers, smokers, and unconscious just after MVA and to have fewer years of education, less severe injuries, less posttraumatic symptoms, and lower cooperativeness as assessed by the Temperament and Character Inventory. Logistic regression analysis revealed that male sex, unconsciousness during MVA, low cooperativeness, and less severe injuries were significant predictors of dropout. The literature says that male sex and unconsciousness just after MVA might be protective factors against MVA-related PTSD, whereas low cooperativeness is a risk factor for general mental problems. To summarize, it is expected that those who drop from the follow-up are unlikely to have MVA-related PTSD, but might have mental problems independent of injury.     

Effects of HNS-32, a novel antiarrhythmic agent, on guinea-pig myocardium.

The electrophysiological and mechanical effects of HNS-32, a novel azulene-1-carboxamidine derivative with antiarrhythmic activity, were studied in isolated guinea-pig myocardial preparations. HNS-32 (10(-6)-10(-4) mol/l) concentration-dependently decreased the maximum rate of rise (V(max)) of action potential in isolated papillary muscle; the potency was the same or slightly higher than that of disopyramide. At 10(-4) mol/l, HNS-32 also shortened the action potential duration (APD) and depolarized the resting membrane potential; these effects were similar to those of 10(-5) mol/l verapamil. HNS-32 (10(-7)-10(-4) mol/l), as well as verapamil (10(-8)-10(-5) mol/l) and disopyramide (10(-6)-10(-3) mol/l), had concentration-dependent negative chronotropic and negative inotropic effects on isolated right atrial and right ventricular papillary muscle preparations, respectively. The concentration-response relationship for the positive chronotropic effect of isoproterenol was not affected by HNS-32 (10(-5) mol/l). In isolated ventricular myocytes, HNS-32 (10(-6)-10(-4) mol/l) concentration-dependently inhibited the peak amplitude of the L-type Ca(2+) current. These results suggest that NHS-32 has V(max) reducing activity on myocardial tissue, which may be responsible for antiarrhythmic effect. The drug may also have additional effect on the Ca(2+) channel at higher concentrations.     

Immunoscintigraphy of human tumors transplanted in nude mice with radiolabeled anti-ras p21 monoclonal antibodies

Anti-ras p21 monoclonal antibody (RASK-3) was used for immunoscintigraphy of human cancer cell lines in nude mice. Iodine-125-labeled RASK-3 was injected into nude mice with either human colon cancers (FCC-1 or BM-314) or lung cancer (KNS-62). Clear images were obtained in all three cancers 7 days after the injection of antibody. No localization of 125I-labeled control monoclonal antibody was observed. The ratio of tissue/blood radioactivity and % ID/g in the tumor were significantly higher than other organs by Day 8. The specific localization index examined by 131I-RASK-3 and 125I-control monoclonal antibody was also higher in the tumor than in other tissues. In the in vitro study, binding of RASK-3 to tumor cells increased significantly by treatment of cells with either lysolecithin or periodate-lysine-paraformaldehyde, which confirmed the intracellular localization of ras p21. The mechanism by which anti-ras p21 antibodies accumulate in tumor sites could be the necrotic changes in tumor cells or changes in membrane permeability of non-necrotic cells. These results provide a strong rationale for the utilization of ras p21 as a target antigen in the imaging of a variety of human cancers.     

Arthroscopic studies of variants of the anterior horn of the medial meniscus

The objective of this study was to arthroscopically analyse the morphology and dynamics of variants of the anterior horn of the medial meniscus of the knee (VAMM) and to then consider the pathological significance of these variants. VAMM was defined as knees in which the anterior horn of the medial meniscus is not attached to the tibia. Between April 1992 and March 1995, arthroscopy was performed on 953 knees of 903 patients. At the time of this examination, observation and probing were performed to determine the condition of the synovium, the synovial plica, the cartilage in all compartments, the meniscus, the cruciate ligaments, and the popliteal tendon. In particular, detailed examination was made of the anterior horn of the medial meniscus with regard to the point of insertion to the tibia and the degree of movement in knee flexion/ extension. Cases of VAMM diagnosed on the basis of the arthroscopic findings were classified into the following four categories: the ACL (anterior cruciate ligament) type, where the anterior horn of the medial meniscus was attached to the ACL; the transverse ligament type, where the anterior horn of the medial meniscus was attached to the transverse ligament; the coronary ligament type, where the anterior horn of the medial meniscus was attached to the coronary ligament; and the infrapatellar fold type, where the anterior horn of the medial meniscus was attached to the infrapatellar synovial fold. These patients were then analyzed with regard to the arthroscopic findings and the intra-articular lesions other than VAMM. In 98 (10.9%) of the total patients, 103 knees were classified as VAMM. Classification of those 103 knees using the above criteria showed 39 ACL type knees, 51 transverse ligament type knees, 11 coronary ligament type knees, and 2 infrapatellar fold type knees. The arthroscopic findings indicated that the anterior horn of the medial meniscus was not attached directly to the tibia in any of these knees. Probing and flexion/extension of the knee revealed hypermobility at the anterior horn of the medial meniscus. In this study, anterior knee pain syndrome was diagnosed in 12 (11.7%) of the 103 VAMM knees. In addition, there was no clear history of trauma in 20 of 23 knees found to have an isolated medial meniscus tear. In these cases, even detailed arthroscopic observation proved the causes of the symptoms or injury. On the basis of these findings, we surmised that the anterior portion shows hypermobility at the time of flexion/extension of the knee, regardless of the type of VAMM. In this study, we discussed the possibility that the existence of VAMM may become the cause of pain or injury to the meniscus.