Bradykinin system is involved in endometriosis-related pain through endothelin-1 production

BACKGROUND

Endometriosis is a gynaecological disease exhibiting severe pelvic pain, but the mechanism of pain production remains unknown. Bradykinin (BK) is known as an inflammatory mediator, and shows elevated levels in inflammatory diseases such as rheumatoid arthritis. In the present study, we evaluated whether BK is involved in endometriosis-related pain.

METHODS

Endometriotic lesions were used for immunohistochemistry. Primary cultures of endometriotic stromal cells (ESC) were stimulated with IL-1β and/or BK. Quantitative RT-PCR was used to evaluate the mRNA expressions of BK receptors (BKR) and endothelin-1 in ESC. The concentration of endothelin-1 in cystic fluid of endometrioma or non-endometrioma was measured with ELISA. The conditioned medium of ESC stimulated with IL-1β and/or BK was injected intraplantarly in mice, and evaluated whether pain-related licking behaviour was elicited.

RESULTS

The expressions of BK and BKR in endometriotic lesions were observed by immunohistochemistry. In vitro experiments showed that IL-1β induced BKR-B1 and B2 on ESC. Activation of these receptors by BK significantly induced endothelin-1 expression in ESC, which was negated completely by HOE-140, a BKR-B2 antagonist. The cystic fluid of endometrioma contained higher amount of endothelin-1 compared to non-endometrioma. Intraplantar injection of the conditioned medium of ESC treated with IL-1β and BK significantly induced licking behaviour, which was suppressed with BQ-123, an endothelin type-A receptor antagonist.

CONCLUSIONS

The present study demonstrated the presence and the function of the BK axis in endometriosis, and established a potential new therapy target for endometriosis-related pain.

SIGNIFICANCE

The present study demonstrated (1) the presence and the function of the BK system in endometriosis, (2) activation of BKR induced endothelin-1 in endometriotic lesion and (3) blocking endothelin-1 was effective to decrease pain.

Rat Cytomegalovirus Vaccine Prevents Accelerated Chronic Rejection in CMV-Naïve Recipients of Infected Donor Allograft Hearts

Cytomegalovirus accelerates transplant vascular sclerosis (TVS) and chronic rejection (CR) in solid organ transplants; however, the mechanisms involved are unclear. We determined the efficacy of a CMV vaccine in preventing CMV-accelerated rat cardiac allograft rejection in naïve recipients of CMV+ donor hearts. F344 donor rats were infected with RCMV 5 days prior to heterotopic cardiac transplantation into CMV-naïve or H2 O2 -inactivated RCMV-vaccinated Lewis recipients. Recipients of RCMV-infected donor hearts rejected at POD59, whereas vaccinated recipients exhibited a significantly prolonged time to rejection-POD97, similar to recipients of uninfected donor hearts (POD108). Although all of the donor hearts were preinfected, the vaccinated recipients had lower graft and PBMC viral loads at POD 7 compared to unvaccinated controls. Adoptive T cell and passive antibody transfers from vaccinated Lewis rats into naïve recipients demonstrate that both T-cell and B-cell arms of the adaptive immune response provide protection against CMV-accelerated rejection. Similar findings were obtained when testing three different adjuvants in passive transfer experiments. We have determined that the timing of the vaccine prior to transplantation and the specific adjuvant play critical roles in mediating anti-viral responses and promoting graft survival. CMV vaccination prior to transplantation may effectively increase graft survival.

Randomized clinical trial: rikkunshito in the treatment of functional dyspepsia--a multicenter, double-blind, randomized, placebo-controlled study

BACKGROUND

Rikkunshito, a standardized Japanese herbal medicine, is thought to accelerate gastric emptying and relieve dyspepsia, although no large-scale, randomized, placebo-controlled trials of rikkunshito have been conducted. This study aimed to determine the efficacy and safety of rikkunshito for treating functional dyspepsia (FD).

METHODS

FD patients received 2.5 g rikkunshito or placebo three times a day for 8 weeks in this multicenter, randomized, placebo-controlled, parallel-group trial. The primary end point was the proportion of responders at 8 weeks after starting test drug, determined by global patient assessment (GPA). The improvement in four major dyspepsia symptoms severity scale was also evaluated. In addition, plasma ghrelin levels were investigated before and after treatment.

KEY RESULTS

Two hundred forty-seven patients were randomly assigned. In the eighth week, the rikkunshito group had more GPA responders (33.6%) than the placebo (23.8%), although this did not reach statistical significance (p = 0.09). Epigastric pain was significantly improved (p = 0.04) and postprandial fullness tended to improve (p = 0.06) in the rikkunshito group at week 8. Rikkunshito was relatively more effective among Helicobacter pylori-infected participants (rikkunshito: 40.0% vs placebo: 20.5%, p = 0.07), and seemed less effective among H. pylori-uninfected participants (rikkunshito: 29.3% vs placebo: 25.6%, p = 0.72). Among H. pylori-positive individuals, acyl ghrelin levels were improved just in rikkunshito group. There were no severe adverse events in both groups.

CONCLUSIONS & INFERENCES

Administration of rikkunshito for 8 weeks reduced dyspepsia, particularly symptoms of epigastric pain and postprandial fullness. (UMIN Clinical Trials Registry, Number UMIN000003954).

Note: Reflection-type micro multipoint laser Doppler velocimeter for measuring velocity distributions in blood vessels

We have developed a laser Doppler velocimeter (LDV) for measuring velocity distributions in blood vessels. We converted a transmission-based LDV into a reflection-based LDV to make it suitable for clinical applications. The velocity distribution image of a serpentine flow channel obtained could be qualitatively explained by the numerical results. Finally, we evaluated the system by using it to measure injection of blood into a glass tube by a syringe pump. The results obtained demonstrate that erythrocytes can be used as seeding particles for the reflection-type micro multipoint LDV. The results obtained are useful as basic data for clinical applications.

The role of angiogenic and wound repair factors during CMV-accelerated transplant vascular sclerosis in rat cardiac transplants

Human cytomegalovirus (HCMV) accelerates transplant vascular sclerosis (TVS), a consequence of angiogenesis (AG) and wound repair (WR). While HCMV can be localized to TVS lesions, the low number of infected cells suggests a global effect on target tissues. We used microarray analysis followed by real-time-polymerase chain reaction (RT-PCR) in an RCMV-accelerated TVS rat cardiac transplant model to determine whether CMV activates host WR and AG factors. Dysregulated cellular genes in allografts from RCMV-infected recipients were compared to those from uninfected recipients and native hearts. We demonstrated that RCMV upregulates the genes involved in WR and AG, which was highest during the critical time of TVS acceleration (21-28 days). Using a standard in vitro AG assay, virus and serum-free supernatants collected at 48 h postinfection significantly induced endothelial cell (EC) migration, branching and tubule formation compared to supernatants from mock-infected cells. Supernatants from ultraviolet (UV)-inactivated RCMV-infected cells failed to induce AG, indicating that virus replication is required. Upregulation of WR and AG genes occurs during the critical period of CMV-accelerated TVS. Targeting these genes may prevent this process and improve allograft survival.

Less invasive technique for EC-IC bypass

BACKGROUND

We introduce less invasive technique for superficial temporal to middle cerebral artery (STA-MCA) anastomosis, and also described an innovative technique to preoperatively identify the recipient artery using three dimensional CT angiography (3D CTA). Objective. In a period of 28 months between January 2004 and April 2006, 39 EC-IC bypass were performed for hemodynamic compromised patients (including 9 patients with Moyamoya disease) using less invasive technique.

METHODS

Operative technique is as follows: 1) A parietal or frontal branch of STA and cortical arteries could be identified on the original images of 3D CTA. The most suitable segment of both the artery provided as donor and recipient arteries for EC-IC bypass. The distance between the afore-mentioned segment of donor artery (STA) and the superior border of the helix were calculated. 2) A 5 cm linear skin incision on the STA, the center of which was the point measured on preoperative 3D CTA, was made. The temporal muscle was divided in the same fashion, and a 3 cm small craniotomy was made. The recipient artery could be identified on the center of the craniotomy. End-to-side anastomosis was performed in the usual way.

RESULTS

Operation times were 115-172 min (mean 154 min) and intraoperative blood loss was 20-60 ml (mean 38 ml). All bypasses were patent on the post-operative 3D CTA.

CONCLUSIONS

This technique for EC-IC bypass was less invasive and cosmetically excellent. 3D CTA provides useful information for planning of the less invasive EC-IC bypass.

Different roles of nitric oxide synthase-1 and -2 between herpetic and postherpetic allodynia in mice

We investigated using the mice role of nitric oxide synthase (NOS) in the spinal dorsal horn in herpetic and postherpetic pain, especially allodynia, which was induced by transdermal inoculation of the hind paw with herpes simplex virus type-1 (HSV-1). The virus inoculation induced NOS2 expression in the lumbar dorsal horn of mice with herpetic allodynia, but not postherpetic allodynia. There were no substantial alternations in the expression level of NOS1 at the herpetic and postherpetic stages. Herpetic allodynia was significantly inhibited by i.p. administration of the selective NOS2 inhibitor S-methylisothiourea, but not the selective NOS1 inhibitor 7-nitroindazole. NOS2 expression was observed around HSV-1 antigen-immunoreactive cells. On the other hand, postherpetic allodynia was significantly inhibited by i.p. administration of 7-nitroindazole, but not S-methylisothiourea. The activity of reduced nicotinamide adenine dinucleotide phosphate diaphorase, an index of NOS1 activity, significantly increased in the laminae I and II of the lumbar dorsal horn of mice with postherpetic allodynia, but not mice without postherpetic allodynia. The expression level of NOS1 mRNA in the dorsal root ganglia was similar between mice with and without postherpetic allodynia. The results suggest that herpetic and postherpetic allodynia is mediated by nitric oxide in the dorsal horn and that NOS2 and NOS1 are responsible for herpetic and postherpetic allodynia, respectively. It may be worth testing the effects of NOS2 and NOS1 inhibitors on herpetic pain and postherpetic neuralgia in human subjects, respectively.

Treatment of cerebral aneurysms: surgical clipping and coil embolization

SUMMARY

The present series provides a balanced overview of the treatment of aneurysms in surgical clipping and coil embolization. Between January 2004 and March 2006, 76 consecutive patients with cerebral aneurysms underwent endovascular embolization and/or surgical clipping. Of these, 42 patients suffered an aneurysmal subarachnoid hemorrhage (SAH), while the remaining 34 patients had nonruptured cerebral aneurysms. Of the 23 surgically treated patients, 17 (73.9%) achieved a favorable outcome. Of the 19 patients who underwent endovascular embolization, 12 (63.2%) achieved a favorable outcome. Three patients (15.8%) who underwent endovascular embolization needed to undergo re-treatments, while no re-treatment was needed in the surgically treated patients. Of the 34 nonruptured aneurysms, 12 (35.3%) were treated using surgical clipping, while 22 (64.7%) underwent endovascular embolization. The complication rates of the two treatment modalities demonstrated no significant difference. A combined microsurgical-endovascular team approach is thus considered to provide the most effective means to achieve favorable outcomes for patients with cerebral aneurysms.

Propofol formulated with long-/medium-chain triglycerides reduces the pain of injection by target controlled infusion

BACKGROUND

Propofol is a widely used intravenous anesthetic although its injection pain is a common and unpleasant problem. Long-/medium-chain triglyceride (LCT/MCT) propofol has been introduced, as its low free propofol content is expected to reduce injection pain compared with LCT propofol. Target controlled infusion (TCI) differs from conventional induction in the initial infusion pattern. During induction using TCI, we investigated injection pain caused by two propofol solutions with different triglyceride compositions.

METHODS

Fifty patients, ASA I-II, with adequate communicative ability, were randomly assigned to two groups. TCI was conducted with Diprifusor for LCT and with BeComSim (custom-made software) for LCT/MCT. The target blood concentration was set at 4 microg/ml for both groups. At 30, 60, and 120 s after the infusion, patients were asked questions regarding the severity of pain on a 0-10 pain score. The total dose of propofol and the time required to induce anesthesia were also investigated.

RESULTS

The LCT/MCT propofol group had a larger number of pain-free patients and showed lower severity of pain than the LCT group [the number of pain-free patients being 11 and 3, respectively (P < 0.05), and median maximum pain being 0 and 4.5, respectively (P < 0.01)]. The dose and time required for induction were not significantly different between the groups (dose of 84 +/- 27 and 80 +/- 24 mg, respectively, and time of 119 +/- 60 and 107 +/- 55 s, respectively).

CONCLUSION

Our study showed that the frequency and severity of pain during TCI induction with propofol could be significantly reduced using LCT/MCT propofol rather than LCT propofol.

Effects of ketamine and propofol on inflammatory responses of primary glial cell cultures stimulated with lipopolysaccharide

BACKGROUND

Ketamine has been reported to exert anti-inflammatory effects on macrophages stimulated with lipopolysaccharide (LPS) in vitro and in vivo. Several studies have reported conflicting results regarding the effects of propofol on cytokine production from immune cells. However, there have been no reports of the effects of these agents on inflammatory responses in glial cells. We investigated the effects of ketamine and propofol on LPS-induced production of nitric oxide, tumour necrosis factor-alpha (TNF-alpha) and prostaglandin E(2) (PGE(2)) from primary cultures of rat glial cells in vitro.

METHODS

Glial cells were stimulated with LPS in the absence and presence of various concentrations of ketamine (30-1000 microM) or propofol (30 and 300 microM). Nitric oxide released into the culture media was determined by measuring nitrite using the Griess reaction, and concentrations of TNF-alpha and PGE(2) were measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Ketamine reduced LPS-induced TNF-alpha production without significant inhibition of nitrite release in mixed glial cells, astrocyte cultures and microglial cultures. Ketamine also inhibited LPS-induced production of PGE(2) in astrocyte cultures. In contrast, propofol had no effect on LPS-induced nitrite or TNF-alpha production in mixed glial cells.

CONCLUSIONS

The data demonstrate that ketamine inhibited some of the inflammatory responses of both astrocytes and microglial cells treated with LPS without causing major change in nitric oxide release. Propofol had no effect on the production of nitric oxide or TNF-alpha from LPS-stimulated glial cells.

Effects of barbiturates on ATP-sensitive K channels in rat substantia nigra

ATP-sensitive K channels are widely expressed in cytoplasmic membranes of neurons, and they couple cell metabolism to excitability. They are thought to be involved in neuroprotection against cell damage during hypoxia, ischemia and excitotoxicity by hyperpolarizing neurons and reducing excitability. Although barbiturates are often used in patients with brain ischemia, the effects of these agents on neuronal ATP-sensitive K channels have not been clarified. We studied the effects of thiopental and pentobarbital on surface ATP-sensitive K channels in principal neurons of rat substantia nigra pars compacta. Whole cell voltage- and current-clamp recordings were made using rat midbrain slices. ATP-sensitive K channels were activated by intracellular dialysis with an ATP-free pipette solution during perfusion with a glucose-free solution. When the pipette solution contained 4mM ATP and the perfusing solution contained 25 mM glucose, the membrane current at -60 mV remained stable. When intracellular ATP was depleted, hyperpolarization and an outward current developed slowly. Although thiopental did not affect the membrane current in the presence of ATP and glucose, it reversibly inhibited the hyperpolarization and outward current induced by intracellular ATP depletion at 100 and 300 microM. Thiopental reduced the ATP depletion-induced outward current by 4.7%, 36.7% and 87% at 30, 100 and 300 microM, respectively. The high dose of pentobarbital also exhibited similar effects on ATP-sensitive K channels. These results suggest that barbiturates at high concentrations but not at clinically relevant concentrations inhibit ATP-sensitive K channels activated by intracellular ATP depletion in rat substantia nigra.

Chronic ethanol consumption does not affect action of propofol on rat hippocampal acetylcholine release in vivo

BACKGROUND

The aim of this study was to examine ethanol-consumption-related changes in the effects of propofol on rat hippocampal acetylcholine (ACh) release.

METHODS

Male Sprague-Dawley rats received a solution of ethanol (20% v/v) for 24 weeks while controls received tap water. The effects of propofol were examined by in vivo microdialysis, with ACh release from the hippocampal regions determined by high-performance liquid chromatography with electrochemical detection (HPLC-ECD).

RESULTS

Propofol 50 mg kg(-1) i.p. significantly decreased basal hippocampal ACh release in ethanol-treated and control rats by 50.4 (sem 4.7)% and 38.3 (11.1)%, respectively. Propofol 100 mg kg(-1) i.p. significantly decreased basal hippocampal ACh release in ethanol-treated and control rats by 67.5 (3.7)% and 55.9 (7.4)%, respectively. The reduction in hippocampal ACh release induced by 50 or 100 mg kg(-1) i.p. propofol was not significantly different between ethanol-treated and control rats. There was no significant difference in the duration of sleep between the two groups.

CONCLUSIONS

These results demonstrate that chronic ethanol consumption does not augment the inhibitory actions of propofol on rat hippocampal ACh release. These findings appear to be inconsistent with the notion that chronic ethanol intake enhances the propofol-induced inhibition of the hippocampal cholinergic system and related mental dysfunction.

Deduced primary structure of two forms of vitellogenin in Japanese common goby (Acanthogobius flavimanus)

Complete nucleotide sequences of two forms of vitellogenin (Vg) cDNA in Japanese common goby were determined from a liver cDNA library of E(2)-treated male fish. These two Vg cDNAs contained complete open reading frames encoding 1664 and 1238 amino acid residues including signal peptides, respectively. From comparison of the deduced amino acid sequences of both Vgs and the partial amino acid sequences of the yolk proteins, the longer sequence was concluded to be cDNA of the Vg-530 and the shorter one was that of the Vg-320 of the Japanese common goby which were reported in our previous paper. The deduced sequence of Vg-530 without signal peptide was arranged by lipovitellin heavy-chain (LvH), phosvitin (Pv), lipovitellin light-chain (LvL), and beta'-component beta'-c) domains from the N-terminus, and showed a range of 40-45% sequence identity to those of other fish. Furthermore, the deduced sequence of Vg-320 showed no obvious Pv domain, has a shortened C-terminal coding region after the LvH domain, and showed a close similarity to the phosvitin-less Vg of zebrafish. Moreover, biochemical analysis of the yolk proteins verified that Vg-530 cleaves into the Lv-Pv complex (molecular mass: 470 kDa) and beta'-c (33 kDa), while Vg-320 showed no change when incorporated into oocytes. The present study demonstrated the existence of the two different forms of Vgs at both the cDNA and protein level, and showed molecular alteration of the two Vgs during vitellogenesis. Two Vg sequence data will aid in designing nucleotide probes for detecting Vg gene expressions as a biomarker of environmental estrogens.

Opposite effects of depressant and convulsant barbiturate stereoisomers on acetylcholine release from the rat hippocampus in vivo

BACKGROUND

It has been shown that the R(-) isomer of 1-methyl-5-phenyl-5-propyl barbituric acid (MPPB) induces loss of the righting reflex (LRR), while S(+)-MPPB causes pure excitatory effects, including convulsions, in vivo.

METHODS

We studied the effects of the depressant and convulsant MPPB stereoisomers on rat hippocampal acetylcholine (ACh) release in vivo, using a brain microdialysis technique in freely moving animals.

RESULTS

R(-)-MPPB 60 and 90 mg x kg(-1) i.p. decreased ACh release from the rat hippocampus by 44.1 (8.2)% and 60.8 (8.2)%, respectively. In the hippocampus, the local application of bicuculline, a gamma-aminobutyric acid (GABA)(A) receptor antagonist, 1 micromol litre(-1) antagonized the inhibitory effects of R(-)-MPPB 90 mg x kg(-1) i.p. In contrast, R(-)-MPPB, S(+)-MPPB 60 and 90 mg x kg(-1) i.p. increased ACh release to 151.8 (6.8)% and 169.6 (11.1)% of the basal release, respectively.

CONCLUSIONS

Our results demonstrated that R(-)-MPPB decreased, while S(+)-MPPB increased, rat hippocampal ACh release and that the inhibitory effects of R(-)-MPPB may involve the GABA(A) receptor in vivo. These data imply that changes in hippocampal ACh due to these agents may be related to their central inhibitory and stimulatory actions in vivo.

Magnetic resonance imaging findings in schizophrenia and atypical psychoses

The differences among MRI findings were studied in schizophrenic psychoses. The schizophrenics and atypical psychotics had significant reductions in bilateral hippocampal volumes compared to controls, but the two patient groups did not differ from each other. As for ventricle volume, the schizophrenics showed significantly larger temporal horns and third ventricle than normal controls, whereas atypical psychotics did not. Moreover, the left temporal horn in the schizophrenics was significantly larger than that seen in the atypical psychotics. By cluster analysis, schizophrenics and atypical psychotics were found to have a tendency to be distributed in different groups. These results might be considered to support the classification of schizophrenic psychoses into schizophrenia and atypical psychoses.

Mechanisms of modulation of neuronal nicotinic receptors by substance P and OAG

Substance P is known to modulate neuronal nicotinic acetylcholine receptors (nAChRs) in the sympathetic nervous system. There are two conflicting proposals for the mechanism of this effect, an indirect action mediated by protein kinase C (PKC) and a direct interaction with receptor subunits. We studied the mechanisms of this effect in PC-12 cells. Substance P enhanced the decay of the nicotine-induced whole cell current. This effect was fast in its onset and was not antagonized by guanosine 5'-O-(2-thiodiphosphate), a G protein blocker, or staurosporine, a nonselective PKC blocker. Staurosporine failed to reverse the inhibition by 1-oleoyl-2-acetyl-sn-glycerol (OAG), a synthetic diacylglycerol analog known to activate PKC. The inhibitory effects of the peptide and OAG were preserved in excised patches, but substance P applied to the extra patch membrane was ineffective in the cell-attached patch configuration. We conclude that substance P modulates neuronal nAChRs most likely by direct interactions with the receptors but independently from activation of PKC or G proteins and that PKC does not participate in modulation by OAG.

Involvement of leukotriene B(4) in substance P-induced itch-associated response in mice

Intradermal injection of substance P elicits an itch sensation in human subjects and an itch-associated response in mice. The substance P-induced itch-associated response in mice is not inhibited by antihistamine. Therefore, the mechanisms of substance P-induced itch-associated response are unclear. In this study, we demonstrated one of the mechanisms. Substance P induces an arachidonate cascade to produce prostaglandins and leukotriene. In this study we considered whether arachidonate metabolites are involved in the substance P-induced itch-associated response. A phospholipase A(2) inhibitor arachidoryltrifluoromethyl ketone inhibited the substance P-induced itch-associated response in mice. Pre treatment with the glucocorticoids betamethasone and dexamethasone also produced inhibition of the substance P-induced itch-associated response in mice as well as humans. The 5-lipoxygenase inhibitor zileuton, but not the cyclooxygenase inhibitors indomethacin and diclofenac, suppressed substance P-induced itch-associated response. The leukotriene B(4) receptor antagonist 5-[2-(2-carboxyethyl)-3-[6-(4-methoxyphenyl)-5E-hexenyl]oxyphenoxy]valeric acid produced inhibition, whereas pranlukast (leukotriene C(4)/D(4)/E(4) receptor antagonist) and 5(Z)-7-[1S,2S, 3S,5R-3-(trans-b-styren)sulfonamido-6,6-dimethylbi cyclo(3,1,1)hept-2-yl]-5-heptenoic acid (EP(1) receptor antagonist) were without effect. Furthermore, when the production of leukotriene B(4) and prostaglandin E(2) was measured in skin injected with substance P and in mouse keratinocytes applied with substance P, the level of both products increased. As leukotriene B(4), but not prostaglandin E(2), also induces the itch-associated response in mice, these results suggest that leukotriene B(4) and keratinocytes, cutaneous cells which produced leukotriene B(4), play an important role in substance P-induced itch-scratch response in mice. Leukotriene B(4) receptor antagonist and 5-lipoxygenase inhibitor may be novel antipruritic drugs.

[Effects of general anesthetics on neuronal nicotinic acetylcholine receptors and their roles in the mechanism of anesthesia]

Neuronal nicotinic acetylcholine receptors (nAchRs) are widely expressed in the central and autonomic nervous systems and have subunit compositions with biophysical and pharmacological properties distinct from those of the receptors at the neuromuscular junction. They are thought to modulate synaptic transmission in the central nervous system (CNS) mainly by regulating the release of neurotransmitters. Although roles of neuronal nAchRs in the CNS are poorly understood, these receptors are involved in cognitive performance, nociception and psychoneurological disorders such as Alzheimer's and Parkinson disease. It is known that both central and peripheral neuronal nAchRs are sensitive to various types of anesthetics. Among those, barbiturates, ketamine, volatile and gaseous anesthetics depress neuronal nAchRs at or below clinical concentrations. Inhibition of neuronal nAchRs by barbiturates is unlikely to contribute to the anesthetic action of barbiturates, since this effect does not correlate with the anesthetic potencies of barbiturate stereoisomers. Relevance of inhibition of these receptors is controversial for anesthetic effects of other anesthetics, because conflicting results have been obtained from comparison of this effect with anesthetic actions of stereoisomers or structurally related compounds. However, it is possible that inhibition of central nAchRs contributes to secondary effects attributed to anesthesia such as impairment in memory and cognitive performance.

BAG-1M, an isoform of Bcl-2-interacting protein BAG-1, enhances gene expression driven by CMV promoter

BAG-1M, one of the isoforms of BAG-1, was reported to bind to DNA and stimulate general transcription when cells were stressed by heat shock (Zeiner, M., et al., Proc. Natl. Acad. Sci. USA 96, 10194-10199, 1999). Here we show that BAG-1M binds and enhances transcriptional activity of Cytomegalovirus (CMV) early gene promoter under unstressed conditions. This activity is unique to BAG-1M in that other isoforms, BAG-1S and BAG-1L, are much weaker in this activity, although all of the isoforms share common ubiquitin-like domain and BAG domain interacting with Hsp70/Hsc70. Deletion analysis of BAG-1M showed that C-terminal BAG domain is necessary to enhance the CMV promoter activity, suggesting that interaction with Hsp70/Hsc70 proteins may mediate this function. Another mutation in N-terminus, BAG-1M K(2-4)A, lost DNA binding capacity and majority of the promoter-enhancing activity. Our study demonstrates that both N-terminal DNA binding site and C-terminal Hsp70/Hsc70 binding site of BAG-1M play an important role in enhancing the CMV promoter activity.

Renal cholesterol accumulation: a durable response after acute and subacute renal insults

Proximal tubular cholesterol levels rise within 18 hours of diverse forms of acute renal tubular injury (eg, myoglobinuria, ischemia/reperfusion, urinary tract obstruction). These increments serve to protect against further bouts of tubular attack (so-called "acquired cytoresistance"). Whether these cholesterol increments are merely transitory, or persist into the maintenance phase of acute renal failure (ARF), has not been previously defined. Furthermore, whether subacute/insidious tubular injury [eg, cyclosporine A (CSA), tacrolimus toxicity], nontubular injury (eg, acute glomerulonephritis), or physiological stress (eg, mild dehydration) impact renal cholesterol homeostasis have not been addressed. This study sought to resolve these issues. Male CD-1 mice were subjected to glycerol-induced ARF. Renal cortical-free cholesterol (FC) and cholesterol ester (CE) levels were determined 3, 5, 7, or 14 days later, and the values contrasted to prevailing blood-urea nitrogen concentrations. The impact of 40 minutes of unilateral renal ischemia plus reflow (3 to 6 days) on mouse cortical FC/CE content was also assessed. Additionally, FC/CE levels were measured in rat renal cortex either 10 days after CSA or tacrolimus therapy, or 48 hours after induction of nephrotoxic serum nephritis. Finally, the impact of overnight dehydration on mouse renal cortical/medullary FC/CE profiles was determined. Compared to sham-treated animals, glycerol, CSA, tacrolimus, ischemia-reperfusion, and nephrotoxic serum each induced dramatic CE +/- FC elevations, rising as much as 10x control values. In the glycerol model, striking correlations (r

CONCLUSIONS

FC/CE accumulation is a hallmark of the maintenance phase of ischemic and nephrotoxic ARF, and can reflect its severity. That cholesterol accumulation can result from glomerular injury and dehydration suggests that it is a generic renal stress response, with potential relevance extending beyond just the phenomenon of acquired cytoresistance.

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Key Words Collapse

MESH Headings

• Acute Kidney Injury/chemically induced
• Acute Kidney Injury/metabolism
• Animals
• Blood Urea Nitrogen
• Cholesterol/metabolism
• Cholesterol Esters/metabolism
• Cyclosporine/toxicity
• Dehydration/physiopathology
• Glomerulonephritis/metabolism
• Glycerol/toxicity
• Ischemia/metabolism
• Kidney/blood supply
• Kidney/metabolism
• Kidney/pathology
• Kidney Cortex/metabolism
• Kidney Medulla/metabolism
• Kidney Tubules/drug effects
• Kidney Tubules/metabolism
• Kidney Tubules/pathology
• Male
• Mice
• Nephritis/metabolism
• Nephritis/pathology
• Rats
• Rats, Sprague-Dawley
• Reperfusion
• Tacrolimus/toxicity

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Grants

• R01 DK038432 NIDDK NIH HHS
• R01 54200 PHS HHS
• R01 DK 37652 NIDDK NIH HHS
• DK38432 NIDDK NIH HHS
• R37 DK038432 NIDDK NIH HHS

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Affiliation(s)

R A Zager Department of Medicine, Fred Hutchinson Cancer Center, University of Washington, 1100 Fairview Ave. N, Rm. D2-190, Seattle, WA 98109, USA.
T Andoh
W M Bennett

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Induction by carrageenan inflammation of prepronociceptin mRNA in VR1-immunoreactive neurons in rat dorsal root ganglia

Nociceptin (orphanin FQ) may act on primary afferents and be involved in the regulation of nociceptive processing. We have shown, using reverse transcription-polymerase chain reaction (RT-PCR), that carrageenan-produced peripheral inflammation induces the expression of prepronociceptin (PPN) mRNA in the dorsal root ganglia (DRG). The present experiments were conducted to determine the localization of PPN mRNA in primary sensory neurons after peripheral inflammation, using in situ hybridization. An intraplantar injection of carrageenan induced the expression of PPN mRNA in small and medium sized neurons in the DRG; the effect peaked 0.5 h after carrageenan and subsided by 6 h. All neurons positive for PPN mRNA were positive for vanilloid receptor subtype 1 (VR1)-like immunoreactivity and some VR1-immunoreactive neurons were negative for PPN mRNA. The results suggest that peripheral inflammation induces the production of nociceptin in a sub-population of VR1-positive primary sensory neurons and support the idea that nociceptin produced there is involved in the regulation of nociceptive processing.

Signal transduction pathways leading to cell cycle arrest and apoptosis induced by DNA topoisomerase poisons

In this overview, I have summarized the important pathways of stress-induced signal transduction: stabilization and activation of p53 playing a central role in stress-induced cell cycle checkpoint and apoptosis, and activation of ASK1-JNK/p38 pathway often induced by a variety of stress stimuli, which appears to be essentially required for apoptosis to follow.

Results and problems in percutaneous transluminal angioplasty for internal carotid artery stenosis

SUMMARY

Percutaneous transluminal angioplasty (PTA) is currently performed as a therapeutic strategy for the management of the cervical carotid artery stenosis. In our clinic, PTA was performed successfully in all 24 patients initially. Restenosis was observed in 4 of 24 patients who received 3 to 6 month follow-up angiography. Repeated PTA was performed in 4 patients, 3 of whom were successfully treated, while severe wall dissection occurred in 1 patient. Furthermore, asymptomatic rerestenosis was noted in 1 of 4 patients who received repeated PTA. Dissection was noted in 5 of 28 procedures, which occurred more often in the patients with calcified or restenotic lesions. These results suggest that stenting or emergent surgery should be prepared in PTA of the carotid artery stenosis to avoid major complications, especially when the patients have calcified or restenotic lesions.

Effect of a combined administration of 5-fluorouracil and medroxyprogesterone acetate on pyrimidine nucleoside phosphorylases and thymidylate synthetase in 7,12-dimethylbenz

The effect of a combined therapy of medroxyprogesterone acetate (MPA) and 5-fluorouracil (5-FU) on tumor size, pyrimidine nucleoside phosphorylase (PyNPase) activity, and thymidylate synthetase (TS) activity was examined in Sprague-Dawley (SD) rats with 7,12-dimethylbenz[a]anthracene (DMBA)-induced mammary tumors. MPA augmented the antitumor activity of 5-FU and protected against body weight-loss due to 5-FU administration. PyNPase activity of both the MPA group and the MPA+5-FU group tended to increase compared with that of the 5-FU alone group. TS inhibition levels in the MPA+5-FU group tended to increase compared with those in the 5-FU alone group. These results indicate that MPA tended to augment antitumor activity of 5-FU and to reduce the side effects caused by 5-FU.

[A case of sarcoidosis acutely aggravated with high fever and diffuse interstitial pulmonary infiltrates]

We present a case of sarcoidosis acutely aggravated with high fever and diffuse interstitial pulmonary infiltrates in a female patient at the age of 64. Sarcoidosis was diagnosed in another hospital as a result of iritis, chest radiography findings, and a negative reaction in a tuberculin skin test. She was admitted to our hospital because of dyspnea and a high temperature of 39 degrees C in February 1994. A marked hypoxemia (PaO2 46.5 torr) was found in arterial blood gas analysis. Chest radiography revealed a bilateral diffuse reticulo-nodular shadows, and chest CT showed ground glass opacity predominant posteriorly. Analysis of bronchoalveolar lavage fluid revealed an increase in lymphocytes and an increased ratio of CD4 to CD8 T lymphocyte. Transbronchial lung biopsy revealed lymphocytic alveolitis and proliferation of epithelioid cell granulomas in the alveolar septa and intraalveolar spaces. The patient was treated for deterioration of sarcoidosis with 40 mg of prednisolone and her respiratory status and the radiographic findings improved rapidly. With dose tapering of prednisolone, dyspnea and deterioration of the radiographic findings occurred, but with addition of a weekly low dose of methotrexate, dose reduction of prednisolone was achieved.

Inhibitory effects of barbiturates on nicotinic acetylcholine receptors in rat central nervous system neurons

BACKGROUND

Neuronal nicotinic acetylcholine receptors (nAChRs) are widely expressed in the central and autonomic nervous systems. The authors have previously shown that depressant and convulsant barbiturates both inhibit the ganglion-type nAchRs in PC12 cells. However, the central and gangliontype receptors have different subunit composition and pharmacologic properties. In this study, the authors investigated the effects of thiopental, depressant [R(-)] and convulsant [S(+)] stereoisomers of 1-methyl-5 phenyl-5-propyl barbituric acid (MPPB) on neuronal nAChRs in the rat central nervous system to explore significance of these effects in barbiturate anesthesia.

METHODS

Whole-cell currents were measured in acutely dissociated rat medial habenula (MHb) neurons by applying 10 or 100 microM nicotine in the absence or presence of thiopental 3-100 microM. Effects of R(-)- and S(+)-MPPB on the nicotine-induced current were also studied.

RESULTS

Thiopental suppressed the nicotine-elicited inward current and accelerated the current decay dose-dependently at the clinical relevant concentrations. R(-)- and S(+)-MPPB both inhibited the nicotine-induced current dose-dependently without augmenting the current decay. There was no significant difference in the magnitudes of inhibition by R(-)- and S(+)-MPPB.

CONCLUSIONS

Although thiopental suppressed the current mediated through native nAchRs in rat MHb neurons at the clinically relevant concentrations, the depressant and convulsant stereoisomers of MPPB both inhibited the current in the same extent. These findings are consistent with the results previously obtained in the ganglion-type receptors of PC12 cells and suggest that inhibition of nAChRs in MHb neurons is not directly relevant to the hypnotic or anticonvulsive actions of barbiturates.

Gabapentin antinociception in mice with acute herpetic pain induced by herpes simplex virus infection

The effects of systemic and local injections of gabapentin, a novel anticonvulsant agent, were tested on nociceptive behaviors in mice with acute herpetic pain. Transdermal infection with herpes simplex virus type-1 (HSV-1) produced nociceptive hypersensitivity of the infected hind paw to innocuous (allodynia) and noxious mechanical stimulation (hyperalgesia) with von Frey filaments. Systemic administration of gabapentin (10-100 mg/kg, peroral) produced a dose-dependent inhibition of both allodynia and hyperalgesia; gabapentin (30-300 mg/kg) did not affect locomotor activity. Intrathecal injection of gabapentin (10-100 microg/animal) also attenuated dose dependently both nociceptive hypersensitivities. In contrast, intraplantar, intracisternal, and intracerebroventricular administration of gabapentin (10-100 microg/animal) had no effect on the HSV-1-induced nociceptive hypersensitivities. Pretreatment with naltrexone (1 mg/kg) inhibited antinociceptive effect of morphine (5 mg/kg), but not gabapentin (100 mg/kg). Repeated administration of morphine (5 mg/kg, four times) led to tolerance of antinociceptive action, whereas gabapentin (100 mg/kg, four times) had antinociceptive effect even after the forth administration. The present results suggest that gabapentin is effective in the treatment of acute herpetic pain without apparent adverse effects, and analgesic action of gabapentin is mainly mediated by actions on the spinal cord.

Multiple molecular forms of glucagon and insulin in the kaluga sturgeon, Huso dauricus

Five molecular forms of glucagon and two molecular forms of insulin were characterized from the kaluga sturgeon. Substitutions occurred at two to thirteen internal amino acid residues among the five molecular forms of glucagons, indicating that these glucagons were encoded by five distinct genes. The amino acid sequences of two insulins from the kaluga sturgeon were identical to those of paddlefish insulin-II and Russian sturgeon insulin except that kaluga sturgeon insulin-I had an extension of five residues at the B-chain N-terminus. This is the first demonstration that more than two molecular forms of glucagon have been characterized from a single animal species.

Preconditioning regulation of bcl-2 and p66shc by human NOS1 enhances tolerance to oxidative stress

Preconditioning stress induced by a transient ischemia may increase brain tolerance to oxidative stress, and the underlying neuroprotective mechanisms are not well understood. In a series of experiments, we found that endogenous nitric oxide (NO), S-nitrosoglutathione (GSNO), and antioxidants blocked serum deprivation-induced oxidative stress and apoptosis in human neuroblastoma cells. Similar to nuclear redox factor-1 (Ref-1), mRNA of human neuronal nitric oxide synthase (hNOS1) was maximally up-regulated within 2 h after oxidative stress and down-regulated by NO/GSNO and hydroxyl radical (OH) scavenger. A brief preconditioning stress induced by serum deprivation for 2 h caused a delayed increase in the expression of hNOS1 protein and the associated formation of NO and cGMP, which in turn decreased OH generation and stress-related cell death. In addition to inhibiting caspase-3 through a dithiothreitol-sensitive S-nitrosylation process, preconditioning stress concomitantly up-regulated the expression of the anti-apoptotic bcl-2 protein and down-regulated the p66shc adaptor protein. This beneficial cytoprotective process of preconditioning stress is mediated by newly synthesized NO because it can be suppressed by the inhibition of hNOS1 and guanylyl cyclase. Therefore, the constitutive isoform of hNOS1 is dynamically redox-regulated to meet both functional and compensatory demands of NO for gene regulation, antioxidant defense, and tolerance to oxidative stress.

Involvement of blockade of leukotriene B(4) action in anti-pruritic effects of emedastine in mice

The anti-pruritic activity of emedastine difumarate was studied in mice. Emedastine (0.03-0.3 mg/kg) inhibited scratching induced by intradermal injection of histamine (100 nmol/site). Scratching induced by substance P (100 nmol/site) and leukotriene B(4) (0.03 nmol/site), but not by serotonin (100 nmol/site), was also suppressed by emedastine (0.03-0.3 mg/kg). Intradermal injection of substance P increased the cutaneous concentration of leukotriene B(4), which was not affected by emedastine. These results suggest that the inhibition by emedastine of substance P-induced itch-associated response is mediated by the blockade of leukotriene B(4) action. Anti-leukotriene B(4) action, as well as the anti-histamine action, may contribute to the anti-pruritic effects of emedastine.

Development of cholecystokinin and pancreatic polypeptide endocrine systems during the larval stage of Japanese flounder, Paralichthys olivaceus

To understand the developmental process of the endocrine system, which controls the pancreatic exocrine function in Japanese flounder, Paralichthys olivaceus, the expression patterns of cholecystokinin (CCK) and pancreatic polypeptide (PP) during the larval stage were analyzed by immunohistochemistry and in situ hybridization. Expression of CCK in the intestinal epithelia started at 2 days posthatching (dph), 1 day prior to the first feeding. Endocrine pancreatic cells containing insulin were present in the pancreas primodium at hatching, and these endocrine cells formed an islet at 3 dph and developed into the principle islet neighboring gallbladder at 20 dph. However, PP cells were not contained in the principle islet even after metamorphosis. PP cells were contained in the accessory islets differentiated around the proximal part of the pyloric appendages at 30 dph (early metamorphosis stage). Therefore, we infer that the stimulative regulation of pancreatic enzyme secretion by CCK starts to function at the first feeding, whereas the restrictive regulation by PP develops about 1 month later in flounder larvae. In addition, we observed that CCK immunoreactive cells appeared in the accessory islets at 30 dph, similar to PP cells, even though CCK mRNA expression could not be detected in cells from the islets. This indicates the possibility that a peptide that is cross-reacted with the CCK antibody, i.e., gastrin, is synthesized in the flounder islets.

Nonstereoselective inhibition of neuronal nicotinic acetylcholine receptors by ketamine isomers

We have found that racemic ketamine strongly inhibits the current mediated through neuronal nicotinic acetylcholine receptors (nAchRs) in PC12 cells, a rat pheochromocytoma cell line. Ketamine stereoisomers have different potencies for the anesthetic action, with the S-enantiomer being about 3 times as potent as the R-enantiomer. The purpose of this study was to clarify if the inhibitory effects of ketamine on neuronal nAchRs contribute to their anesthetic effect. We compared potencies of ketamine enantiomers for neuronal nAchR inhibition with those for the anesthetic action. S(+) and R(-) ketamine inhibited the nicotine-induced whole-cell current in a dose-dependent manner at the membrane potential of -60 mV. They accelerated the current decay, resulting in the larger effects on the nondesensitized current than on the peak current. There was no significant difference in the concentrations for 50% inhibition between the stereoisomers. The ketamine isomers exerted the same effects on single-channel properties estimated from analysis of the nicotine-induced current noise. These results indicate that the inhibitory action of ketamine isomers on neuronal nAchRs is not stereoselective. Although our findings do not deny possible involvement of these receptors in ketamine anesthesia, they suggest that inhibition of neuronal nAchRs is not primarily responsible for the anesthetic action of this anesthetic.

IMPLICATIONS

We found that inhibition of neuronal nicotinic acetylcholine receptors by ketamine is not stereoselective in PC12 cells. The result suggests that this effect does not directly correlate with the anesthetic action of ketamine.

Eicosapentaenoic acid reduces pulmonary edema in endotoxemic rats

BACKGROUND

Recently, eicosapentaenoic acid (EPA) was found to have an anti-inflammatory effect attributable to diminished synthesis of arachidonic acid metabolites that initiate acute lung injury. We evaluated the ability of dietary EPA supplementation to prevent endotoxin-induced acute lung injury in rats.

MATERIALS AND METHODS

Rats fed a standard diet were divided randomly into two groups: for 2 weeks one group additionally was fed 1000 mg/kg/day of EPA ethyl ester emulsion (EPA rats), while in the other group the diet was supplemented with vehicle alone (control rats). Fatty acid components of alveolar macrophages (AM) were measured, as well as leukotriene (LT) B(4) and LTB(5) production by AM exposed in vitro to calcium ionophore A23187. Plasma concentrations of thromboxane (Tx) B(2), a stable metabolite of TxA(2), were examined 1 h after inducing lung injury with endotoxin (2 mg/kg iv). At 6 h, wet/dry (W/D) weight ratios were calculated for the lungs to assess pulmonary edema, and neutrophils were counted in pulmonary parenchyma and peripheral blood.

RESULTS

Arachidonic acid content and LTB(4) generation in AM were significantly lower in EPA rats than in controls; conversely, EPA content and LTB(5) generation in AM were significantly higher in the EPA group. Neutrophil counts in lung parenchyma and peripheral blood did not differ between groups, but W/D and plasma TxB(2) concentrations were significantly lower in EPA rats.

CONCLUSIONS

EPA supplementation depressed arachidonic acid content and LTB(4) generation in AM and plasma TxB(2) in our model, leading to decreased pulmonary edema.

Yeast glycogen synthase kinase 3 is involved in protein degradation in cooperation with Bul1, Bul2, and Rsp5

The yeast Saccharomyces cerevisiae has four genes, MCK1, MDS1 (RIM11), MRK1, and YOL128c, that encode glycogen synthase kinase 3 (GSK-3) homologs. The gsk-3 null mutant, in which these four genes are disrupted, shows temperature sensitivity, which is suppressed by the expression of mammalian GSK-3beta and by an osmotic stabilizer. Suppression of temperature sensitivity by an osmotic stabilizer is also observed in the bul1 bul2 double null mutant, and the temperature sensitivity of the bul1 bul2 double null mutant is suppressed by multiple copies of MCK1. We have screened rog mutants (revertants of gsk-3) which suppress the temperature sensitivity of the mck1 mds1 double null mutant and found that two of them, rog1 and rog2, also suppress the temperature sensitivity of the bul1 bul2 double null mutant. Bul1 and Bul2 have been reported to bind to Rsp5, a hect (for homologous to E6-associated-protein carboxyl terminus)-type ubiquitin ligase, but involvement of Bul1 and Bul2 in protein degradation has not been demonstrated. We find that Rog1, but not Rog2, is stabilized in the gsk-3 null and the bul1 bul2 double null mutants. Rog1 binds directly to Rsp5, and their interaction is dependent on GSK-3. Furthermore, Rog1 is stabilized in the npi1 mutant, in which RSP5 expression levels are reduced. These results suggest that yeast GSK-3 regulates the stability of Rog1 in cooperation with Bul1, Bul2, and Rsp5.

Pharmacological and immunohistochemical characterization of a mouse model of acute herpetic pain

We have recently found that the infection with herpes simplex virus type-1 (HSV-1) of primary sensory neurons induces nociceptive hypersensitivity to noxious mechanical (hyperalgesia) and tactile stimulation (allodynia) in mice. In the present experiments, we determined the distribution of HSV-1 in the dorsal root ganglia and examined the effects of four analgesic agents on hyperalgesia and allodynia. HSV-1 was inoculated on the unilateral shin. HSV-antigen-positive cells were detected in the L4 and L5 dorsal root ganglia on days 5 and 7, but not day 3, post-inoculation. About 80% of the positive cells were small in size. Allodynia and hyperalgesia appeared on day 5 post-inoculation. Antinociceptive effects of analgesic agents were examined on day 6 post-inoculation. Morphine (1-5 mg/kg, subcutaneous) and gabapentin (10-100 mg/kg, peroral) dose-dependently inhibited both allodynia and hyperalgesia. Diclofenac (10-100 mg/kg, intraperitoneal) also produced antinociceptive effects, but there was a ceiling for the effect on hyperalgesia. Amitriptyline (3, 10 mg/kg, subcutaneous) did not affect allodynia and hyperalgesia. The results suggest that mechanical allodynia and hyperalgesia appeared when HSV-1 proliferated in the sensory neurons. This mouse model may be useful for studying the mechanisms of acute herpetic pain and anti-neuropathic pain agents.

Differential activation of brain-derived neurotrophic factor gene promoters I and III by Ca2+ signals evoked via L-type voltage-dependent and N-methyl-D-aspartate receptor Ca2+ channels

Although the brain-derived neurotrophic factor (BDNF) gene is activated by the intracellular Ca(2+) signals evoked via Ca(2+) influx into neurons, little is known about how the activation of alternative BDNF gene promoters is controlled by the Ca(2+) signals evoked via N-methyl-d-aspartate receptors (NMDA-R) and L-type voltage-dependent Ca(2+) channels (L-VDCC). There is a critical range in the membrane depolarization caused by high K(+) concentrations (25-50 mm KCl) for effective BDNF mRNA expression and transcriptional activation of BDNF gene promoters I and III (BDNF-PI and -PIII, respectively) in rat cortical culture. The increase in BDNF mRNA expression induced at high K(+) was repressed not only by nicardipine, an antagonist for L-VDCC, but also by dl-amino-5-phosphonovalerate, an antagonist for NMDA-R, which was supported by the effects of antagonists on the Ca(2+) influx. Although the promoter activations at 25 and 50 mm KCl were different, BDNF-PIII was activated by either the Ca(2+) influx through NMDA-R or L-VDCC, whereas BDNF-PI was predominantly by the Ca(2+) influx through L-VDCC. Direct stimulation of NMDA-R supported the activation of BDNF-PIII but not that of BDNF-PI. Thus, the alternative BDNF gene promoters responded differently to the intracellular Ca(2+) signals evoked via NMDA-R and L-VDCC.

HTLV-1 tax oncoprotein binds to DNA topoisomerase I and inhibits its catalytic activity

HTLV-1 Tax oncoprotein exerts pleiotropic effects on cellular regulatory systems, such as transcription and the cell cycle, through the interaction with various cellular factors. During our search for additional cellular targets of Tax using a yeast two-hybrid screening system, we isolated a cDNA encoding human DNA topoisomerase I. Tax was demonstrated to bind to topoisomerase I in vitro, and the Tax-topoisomerase I complex was also detected in HTLV-1-infected T-cells by immunoprecipitation. Furthermore, Tax inhibited the catalytic activity of topoisomerase I as measured by relaxation of supercoiled DNA, although complete inhibition was not observed under the conditions used. The binding of topoisomerase I to DNA was inhibited by the addition of the wild type of Tax but not by a mutant of Tax that cannot bind to topoisomerase I. Consistent with these observations, expression of Tax induced an in vivo reduction of the covalent association of topoisomerase I with chromosomal DNA, which accumulates in the presence of camptothecin. These results suggest that Tax has a novel potential to affect various cellular processes such as transcription and maintenance of genomic stability, in which DNA topoisomerase I is involved.

Allodynia and hyperalgesia induced by herpes simplex virus type-1 infection in mice

Human subjects infected with herpes or varicella-zoster viruses complain of pain, such as allodynia, in or near the region with vesicles. However, the mechanisms of the pain are unclear. We show for the first time that infection with herpes simplex virus type-1 (HSV-1) induces allodynia and hyperalgesia in mice. When HSV-1 was inoculated on the hind paw of the mouse, eruption appeared on the back on day 5 post-inoculation, and zosteriform skin lesions were developed on the inoculated side. Allodynia and hyperalgesia became apparent in the hind paw on the inoculated side on day 5 and persisted until at least day 8. HSV-1 DNA was detected in the dorsal root ganglia from days 2 to 8 post-inoculation, with a peak effect on day 5. The application of heat-inactivated HSV-1 induced no allodynia, hyperalgesia and skin lesion. When started from days 0 or 2, repeated treatment with acyclovir, anti-HSV-1 agent, inhibited the appearance of allodynia, hyperalgesia, eruption and the viral proliferation in the dorsal root ganglia. In contrast, when started from days 5 or 6, acyclovir treatment slightly inhibited the development of skin lesions and the viral proliferation, but not allodynia and hyperalgesia. These results suggest that the propagation of HSV-1 in the dorsal root ganglia produces allodynia and hyperalgesia as a result of functional abnormality of the sensory neurons in mice. This may be a useful model for studying the mechanisms of herpetic pain.

Identification and characterization of a deletion mutant of DNA topoisomerase I mRNA in a camptothecin-resistant subline of human colon carcinoma

In previous studies, we established two camptothecin (CPT)-resistant sublines, HT-29 / CPT and St-4 / CPT, from the human colon cancer cell line HT-29 and the human stomach cancer cell line St-4, respectively. Cellular contents of DNA topoisomerase I (topo I) in the resistant cells were eight-fold less than those in the corresponding parental lines. In this study, we have shown expression of two species of the TOP1 mRNA in HT-29 / CPT. The longer mRNA (4.0 kb) is the wild-type TOP1 mRNA, and the shorter mRNA (3.3 kb) proved to have a deletion of 672 bp (nucleotides 58 - 729 or 59 - 730) that caused the in-frame deletion of amino acids 20 - 243 of human topo I. The deleted region is identical to exons 3 - 9 of the TOP1 gene. The expression level of the 3.3-kb mRNA was similar to that of the wild-type mRNA in HT-29 / CPT. St-4 / CPT expressed only the wild-type TOP1 mRNA in lesser amounts than did St-4. Mouse NIH3T3 cells transfected with the wild-type TOP1 cDNA showed higher sensitivity to CPT than the parental cells, whereas those transfected with the deleted TOP1 cDNA showed levels similar to those of the parental cells. Expression of the exogenous TOP1 mRNA was confirmed; however, expression of the truncated topo I was not detected in cells transfected with the deleted TOP1 cDNA. These results suggest that the expression of the deleted TOP1 mRNA led to the low expression of CPT-sensitive topo I in the resistant cells.

Dynorphins directly inhibit neuronal nicotinic acetylcholine receptors in PC12 cells

The authors have previously reported that dynorphin A (1-17), an endogenous kappa opioid agonist, inhibits the current mediated through neuronal nicotinic acetylcholine receptors (nAChRs) without the involvement of opioid receptors or G-proteins. We have further characterized this action to elucidate the mechanisms. The nicotine-induced current was studied in PC12 cells using patch-clamp techniques. In the whole-cell configuration, four kinds of dynorphins with different lengths, dynorphin A (1-17) (1-13) (2-13) and (1-8), similarly inhibited the nicotine-induced inward current at 1 microM and accelerated the current decay. The inhibition by dynorphin A (1-17) was not antagonized by the increasing concentrations of nicotine. The current-voltage relationship revealed that dynorphin's inhibition was voltage independent at the membrane potentials from -30 to -70 mV. The inhibition was not affected by pretreatment with pertussis toxin (PTX) or inclusion of staurosporine into the pipette solution. The inhibitory effect of dynorphin A (1-17) was well preserved in the outside-out patch configuration. Analysis of the nicotine-induced noise and single-channel kinetics revealed that dynorphin A(1-17) reduced open time without changing the amplitude of the unitary current. We found that the inhibitory effect on neuronal nAChRs is shared by all four dynorphins studied. The inhibition appears to be non-competitive and voltage independent. The outside-out recording together with other experiments indicated that a major part of this inhibition is not mediated through cytoplasmic messengers, but based on the direct action of dynorphins on neuronal nAChRs leading to the reduction of open time.

Inhibition of DNA topoisomerases by nidulalin A derivatives

Three cytotoxic dihydroxanthone derivatives, nidulalin A(1), F390B(2), and F390C(3) were evaluated for inhibitory activity against DNA topoisomerases. Compounds 1 and 2 inhibited DNA topoisomerase II with IC50 values of 2.2 microM and 16 microM, and 3 inhibited DNA topoisomerase I with an IC50 value of 5.9 microM.