Lignan derivatives and a norditerpene from the seeds of Vitex negundo

A new phenyldihydronaphthalene-type lignan, vitedoin A (1), a new phenylnaphthalene-type lignan alkaloid, vitedoamine A (2), and a new trinorlabdane-type diterpene, vitedoin B (3), were isolated from the seeds of Vitex negundo along with five known lignan derivatives (4-8). Their chemical structures were determined mainly on the basis of NMR and MS data. Compounds 1, 2, and 4-7 showed stronger antioxidative activity than alpha-tocopherol using the ferric thiocyanate method. Compounds 1, 2, and 4-7 showed higher radical-scavenging effect on the stable free radical, 1,1-diphenyl-2-picrylhydrazyl, than L-cysteine.     

Deactivation by benzodiazepine of the basal forebrain and amygdala in normal humans during sleep: a placebo-controlled [15O]H2O PET study

OBJECTIVE: The authors' goal was to identify differences in regional brain activity between physiological and benzodiazepine-induced sleep to clarify the brain structures involved in the drug's hypnotic effect. METHOD: Using positron emission tomography, they compared regional cerebral blood flow during non-REM sleep in nine volunteers treated with placebo or triazolam, a short-acting benzodiazepine, in a double-blind, crossover design. RESULTS: Blood flow in the basal forebrain and amygdaloid complexes was lower during non-REM sleep when subjects were given triazolam than when they were given placebo. CONCLUSIONS: The hypnotic effect of the benzodiazepines may be mediated mainly by deactivation of the forebrain control system for wakefulness and also by the anxiolytic effect induced by deactivation of the emotional center.     

Transplanted hematopoietic stem cells from bone marrow differentiate into neural lineage cells and promote functional recovery after spinal cord injury in mice

Recovery in central nervous system disorders is hindered by the limited ability of the vertebrate central nervous system to regenerate lost cells, replace damaged myelin, and re-establish functional neural connections. Cell transplantation to repair central nervous system disorders is an active area of research, with the goal of reducing functional deficits. Recent animal studies showed that cells of the hematopoietic stem cell (HSC) fraction of bone marrow transdifferentiated into various nonhematopoietic cell lineages. We employed a mouse model of spinal cord injury and directly transplanted HSCs into the spinal cord 1 week after injury. We evaluated functional recovery using the hindlimb motor function score weekly for 5 weeks after transplantation. The data demonstrated a significant improvement in the functional outcome of mice transplanted with hematopoietic stem cells compared with control mice in which only medium was injected. Fluorescent in situ hybridization for the Y chromosome and double immunohistochemistry showed that transplanted cells survived 5 weeks after transplantation and expressed specific markers for astrocytes, oligodendrocytes, and neural precursors, but not for neurons. These results suggest that transplantation of HSCs from bone marrow is an effective strategy for the treatment of spinal cord injury.     

Decrease in serum leptin by troglitazone is associated with preventing bone loss in type 2 diabetic patients

 The thiazolidinedione (TZD) class of antidiabetic drugs has been shown to inhibit the formation of bone-resorbing osteoclasts in vitro and to decrease bone resorption markers in vivo. These drugs also inhibit the expression of leptin in adipocytes. Less leptin can be associated with higher bone mass, based on analyses of mice deficient in leptin action. Effects of 1-year treatment with troglitazone, a member of the TZDs, on bone mineral density (BMD) and bone metabolism were examined in 25 Japanese type 2 diabetic patients. Glucose metabolism was improved, whereas body mass index and percent body fat did not change throughout the study. The percent change of BMD was negatively correlated with that of serum leptin, whereas it was not associated with changes of bone metabolic markers, type I collagen N-telopeptide (NTx), bone alkaline phosphatase (ALP), body mass index, or HbA1c. Serum leptin decreased in 68% of subjects (responders) after 1-month treatment and was consistently lower than the basal level throughout the treatment. Percent changes of BMD were significantly higher in the responders than in the nonresponders and in nondiabetic subjects at 6 and 12 months. NTx and bone ALP decreased at 1 month but increased thereafter in either group of patients. Thus, it is suggested that the decrease in serum leptin with no reduction in body fat mass by troglitazone is associated with preventing bone loss in type 2 diabetic patients. Hence, TZDs may have an advantage for diabetic patients who have risk factors for osteoporosis. Received: July 7, 2002 / Accepted: November 19, 2002 Offprint requests to: Y. Takeuchi     

Antimicrobial activity of hinokitiol against Legionella pneumophila

Antimicrobial activity of hinokitiol (beta-thujaplicin), which is a major component of the essential oil of Chamaecyparis obtuse, against Legionella pneumophila was investigated experimentally. The quantitative antibacterial assay of hinokitiol was carried out by the disk-diffusion method. The test concentrations of hinokitiol were 0.39 to 25.0 micrograms/disk, and the lowest concentrations of hinokitiol that showed growth inhibition against L. pneumophila were 1.56 micrograms/disk on B-SYE agar and 0.39 microgram/disk on B-SYE agar without iron.     

Cyclooxygenase-2 expression and its relationship with proliferation of colorectal adenomas

BACKGROUND: Cyclooxygenase (COX)-2 may be linked to carcinogenesis. In the previous study, we examined COX-2 expression immunohistochemically in 95 adenomas and reported a significant correlation between its expression and the grade of dysplasia. To clarify the correlation between COX-2 expression and cell proliferation, we investigated Ki-67 labeling index using immunohistochemistry and its correlation with COX-2 expression. METHODS: Immunohistological staining for Ki-67 antigen was performed on 95 colorectal adenomas previously reported. RESULTS: The Ki-67 labeling index was significantly higher in the high-COX-2 group than in the low-COX-2 and negative groups in adenomas with moderate (44.5 +/- 6.4% vs 33.0 +/- 2.6%, 39.0 +/- 6.2%; P = 0.01, P < 0.001, respectively) or severe dysplasia (47.2 +/- 7.6% vs 40.3 +/- 7.2%, 35.0 +/- 5.4%; P = 0.02, P = 0.005, respectively). There was no correlation between Ki-67 labeling index and COX-2 expression in mild dysplasia. CONCLUSIONS: These results suggest that COX-2 may play a causal role in cell proliferation in carcinogenesis.     

Development of a new respirator for organic vapors with a breakthrough detector using a semiconductor gas sensor

A method for determining breakthrough of organic vapors in a respirator cartridge was developed. A thick film semiconductor gas sensor was used as a breakthrough detector. Air containing organic vapor was introduced into the cartridge, and an output signal from the sensor inserted in the downstream flow of the cartridge was recorded on an IC card. Simultaneously, the breakthrough curve was obtained by measuring the vapor concentration at downstream from the respirator cartridge with a gas chromatograph (GC) equipped with a flame ionization detector. When the breakthrough was almost completed, the data recorded in the card were transferred to a personal computer and the change in the output signal from the sensor was compared with the breakthrough curve obtained by the GC. Twelve organic solvents including aromatic hydrocarbons, chlorinated hydrocarbons, acetates, alcohols, ketones, and aliphatic hydrocarbons were tested under low (20%-25%) and high (70%-80%) relative humidity ranges. The sensitivity of the sensor for chlorinated hydrocarbons such as 1,1,1-trichloroethane was relatively low, especially when the relative humidity was high, but the rise time of the sensor output signal was almost the same as or earlier than the breakthrough time by the GC. Based on the experimental results, a new respirator for organic vapors that can detect the end of service life was developed.     

Partial agonist behaviour depends upon the level of nociceptin/orphanin FQ receptor expression: studies using the ecdysone-inducible mammalian expression system

(1) Partial agonism is primarily dependent upon receptor density and coupling efficiency. As these parameters are tissue/model dependent, intrinsic activity in different tissues can vary. We have utilised the ecdysone-inducible expression system containing the human nociceptin/orphanin FQ (N/OFQ) peptide receptor (hNOP) expressed in Chinese hamster ovary cells (CHOINDhNOP) to examine the activity of a range of partial agonists in receptor binding, GTPgamma35S binding and inhibition of adenylyl cyclase studies. (2) Incubation of CHOINDhNOP cells with ponasterone A (PON) induced hNOP expression ([leucyl-3H]N/OFQ binding) of 24, 68, 191 and 1101 fmol mg-1 protein at 1, 2, 5 and 10 microm PON, respectively. At 191 fmol mg-1, protein hNOP pharmacology was identical to that reported for other traditional expression systems. (3) pEC50 values for GTPgamma35S binding ranged from 7.23 to 7.72 (2-10 microm PON) for the partial agonist [Phe1psi(CH2-NH)Gly2]N/OFQ(1-13)-NH2 ([F/G]N/OFQ(1-13)-NH2) and 8.12-8.60 (1-10 microm PON) for N/OFQ(1-13)-NH2 and Emax values (stimulation factor relative to basal) ranged from 1.51 to 3.21 (2-10 microm PON) for [F/G]N/OFQ(1-13)-NH2 and 1.28-6.95 (1-10 microm) for N/OFQ(1-13)-NH2. Intrinsic activity of [F/G]N/OFQ(1-13)-NH2 relative to N/OFQ(1-13)-NH2 was 0.3-0.5. [F/G]N/OFQ(1-13)-NH2 did not stimulate GTPgamma35S binding at 1 microm PON, but competitively antagonised the effects of N/OFQ(1-13)-NH2 with a pKB=7.62. (4) pEC50 values for cAMP inhibition ranged from 8.26 to 8.32 (2-10 microm PON) for [F/G]N/OFQ(1-13)-NH2 and 9.42-10.35 for N/OFQ(1-13)-NH2 and Emax values (% inhibition) ranged from 19.6 to 83.2 for [F/G]N/OFQ(1-13)-NH2 and 40.9-86.0 for N/OFQ(1-13)-NH2. The intrinsic activity of [F/G]N/OFQ(1-13)-NH2 relative to N/OFQ(1-13)-NH2 was 0.48-0.97. (5) In the same cellular environment with receptor density as the only variable, we show that the profile of [F/G]N/OFQ(1-13)-NH2 can be manipulated to encompass full and partial agonism along with antagonism.     

Evaluation of malignancy using Ki-67 labeling index for gastric stromal tumor

Background. Assessment of malignant potential in gastrointestinal stromal tumors (GISTs) is still problematic. The maximum tumor diameter and the mitotic index are generally used as an index of malignancy of GISTs. The Ki-67 labeling index has recently been used as an index of cell growth, and the prognosis of GISTs was reported to be significantly poor when the value of this index was 10% or higher. Methods. Clinicopathological and immunohistological factors were analyzed in 15 patients who underwent surgical resection of gastric stromal tumors at our department between April 1997 and July 2002. The patients were divided into metastasis/recurrence and benign groups. Also, the relationship of changes in the Ki-67 labeling index to the degree of malignancy in recurrent lesions was assessed in an 84-year-old woman who underwent five reoperations because of recurrences in the peritoneum. Results. Significant differences were noted between the metastasis/recurrence and benign groups in relation to the mean maximum tumor diameter (186.7 ± 80.8mm vs 41.3 ± 22.9mm), mitotic index (88.3 ± 5.0/50 high-power fields [HPF] vs 3.0 ± 2.9/50 HPF), and the Ki-67 labeling index (11.4 ± 2.5% vs 0.01 ± 0.51%). In the patient who had metastasis to the liver 3.5 years after initial operation and underwent five reoperations before death, the intervals until detection of recurrence tended to be shortened gradually. The Ki-67 labeling index varied with each operation, and tended to be higher at the time of reoperations than at the initial operation. Conclusion. The maximum tumor diameter, mitotic index, and Ki-67 labeling index were useful as an index of malignancy for gastric stromal tumor. The efficacy of surgical resection alone may be insufficient in patients with disseminated metastasis to the peritoneum.     

Effect of lipopolysaccharide on uterine contractions and prostaglandin production in pregnant rats

OBJECTIVE: Our aim was to evaluate the effect of lipopolysaccharide on prostaglandin production and on contraction of isolated myometrial strips from preterm pregnant rats. STUDY DESIGN: Pregnant Wistar rats on day 17 of gestation were killed 3 hours after intraperitoneal injection of lipopolysaccharide (1.5 mg/kg) or vehicle, with or without pretreatment with indomethacin (5 mg/kg administered intraperitoneally) 1 hour beforehand. Concentrations of endotoxin in maternal serum and amniotic fluid, prostaglandin F2alpha and prostaglandin E2 in amniotic fluid, and progesterone in maternal serum were determined. Longitudinal uterine strips were prepared, placed in organ chambers with Krebs-Ringer solution, aerated with 95% oxygen and 5% carbon dioxide (37 degrees C, pH approximately 7.4), and equilibrated at 1g passive tension. Concentration-contraction relationships to oxytocin were determined. Samples of bathing solution were collected 10 minutes after the concentration of oxytocin was maximal. Prostaglandins and progesterone were measured by radioimmunoassay and endotoxin was measured by the Endospecy (Seikagaku Kogyo, Tokyo, Japan) kit. RESULTS: Lipopolysaccharide treatment significantly increased the levels of prostaglandin F2alpha and prostaglandin E2 in amniotic fluid. Treatment with lipopolysaccharide inhibited the production and release of prostaglandin F2alpha and prostaglandin E2 that were activated by oxytocin in uterine strips and increased the sensitivity of strips to the contractile effect of oxytocin. Indomethacin did not affect the basal or the lipopolysaccharide-activated levels of endotoxin in serum and amniotic fluid and exerted a counteraction on lipopolysaccharide-induced increases in concentrations of prostaglandin F2alpha and prostaglandin E2 in amniotic fluid. Indomethacin counteracted oxytocin-activated production and release of prostaglandin F2alpha and prostaglandin E2 in uterine tissues after lipopolysaccharide administration without changing the sensitivity of uterine strips to oxytocin. Concentrations of progesterone were not changed after lipopolysaccharide, indomethacin, or their combined application, which suggests that the changes described were not associated with alterations in the levels of the hormone. CONCLUSIONS: The activation of the uterine contractile system by prostaglandin and oxytocin during intra-amniotic infection may be one of the causes of preterm delivery. A combination of an oxytocin receptor antagonist and an inhibitor of cyclooxygenase may be beneficial in prevention or treatment of preterm labor.