Paracrine control of mesenteric perivascular axo-axonal interaction

Immunohistochemical study of rat mesenteric arteries showed dense innervation of adrenergic nerves, calcitonin gene-related peptide (CGRP)-containing nerves (CGRPergic nerves), nitric oxide-containing nerves (nitrergic nerves). Double-immunostaining revealed that most CGRPergic or nitrergic nerves were in close contact with adrenergic nerves. CGRPergic and transient receptor potential vanilloid-1 (TRPV1)-immunopositive nerves appeared in the same neurone. In rat perfused mesenteric vascular beds without endothelium and with active tone, perfusion of nicotine, or bolus injection of capsaicin and acetylcholine and periarterial nerve stimulation (PNS) lowered pH levels of out flowed perfusate concomitant with vasodilation. Cold-storage denervation of preparations abolished pH lowering induced by nicotine and PNS. Guanethidine inhibited PNS- and nicotine-, but not acetylcholine- and capsaicin-, induced pH lowering. Pharmacological analysis showed that protons were released not only from adrenergic nerves but also from CGRPergic nerves. A study using a fluorescent pH indicator demonstrated that nicotine, acetylcholine and capsaicin applied outside small mesenteric artery lowered perivascular pH levels, which were not observed in Ca(2+) free medium. Exogenously injected hydrochloric acid in denuded preparations induced pH lowering and vasodilation, which was inhibited by denervation, TRPV1 antagonists and capsaicin without affecting pH lowering. These results suggest that excitement of adrenergic nerves releases protons to activate TRPV1 in CGRPergic nerves and thereby induce vasodilation. It is also suggested that CGRPergic nerves release protons with exocytosis to facilitate neurotransmission via a positive feedback mechanism.

Preseasonal prophylactic treatment with antihistamines suppresses nasal symptoms and expression of histamine H₁ receptor mRNA in the nasal mucosa of patients with pollinosis

Administration of antihistamines 2-4 weeks before the pollen season showed a greater inhibitory effect on nasal allergy symptoms in patients with seasonal allergic rhinitis. However, the mechanism of slow-onset effects of preseasonal treatment with antihistamines remains unclear. Here, we investigated the effect of preseasonal prophylactic treatment with antihistamines on nasal symptoms and the expression of histamine H₁ receptor (H1R) mRNA of the nasal mucosa in patients with cedar pollen pollinosis. During the peak pollen period, the expression of H1R mRNA in the nasal mucosa and the scores of sneezing and watery rhinorrhea in patients receiving preseasonal prophylactic treatment with antihistamines were significantly suppressed in comparison with those in the patients without treatment. Moreover, there was a significant correlation between the nasal symptoms and the expression of H1R mRNA in both patients with or without preseasonal prophylactic treatment. These findings suggest that preseasonal prophylactic treatment with antihistamines is more effective than on-seasonal administration to patients with pollinosis in reducing nasal symptoms during the peak pollen period by suppressing H1R gene expression in the nasal mucosa.

The pH Dependent Uptake of Enoxacin by Rat Intestinal Brush-border Membrane Vesicles

The mechanism of the intestinal transport of enoxacin, an orally active fluoroquinolone antibiotic, has been investigated using brush-border membrane vesicles isolated from rat small intestine. The initial rate and time-course of enoxacin uptake were considerably dependent upon the medium pH (pH 5·5 > pH 7·5) and upon the percent ionization of the carboxyl group (pKa 6·2, anionic charge), namely, the degree of uptake of cationic form was higher than that of the zwitterionic form. There was evidence of transport into the intravesicular space as shown by the effect of extravesicular medium osmolarity on enoxacin uptake at steady state (30 min). This transport across the brush-border membrane was stimulated by the valinomycin-induced K+-diffusion potential (interior negative) and an outward H+-diffusion potential. Furthermore, changing the pH of the medium from 5·5 to 7·5 significantly decreased the effect of valinomycin-induced K+-diffusion potential on the enoxacin uptake. These results suggest that the uptake behaviour of the cationic form of enoxacin plays an important role in the intestinal absorption process of enoxacin.

A case of adult T cell leukemia/lymphoma presenting as severe tracheal stenosis

A 57-year-old woman was referred to our hospital for further examination of a tracheal stenosis shown on computed tomography findings. Bronchoscopy revealed multiple protruding tumors in the lumen of the trachea. Cytological findings of the cell block material from pleural effusion indicated that the T-cell lymphoma was composed of pleomorphic lymphoid cells. Serum human T-cell leukemia virus type 1 antibody was positive and supported the clinical diagnosis of ATLL. Systemic chemotherapy induced the remarkable improvement of the lesions, the infiltrative lung shadow and the soft tissue neoplasm. We report a rare case of adult T cell leukemia/lymphoma (ATLL) with endobronchial involvement.

Increased microcirculation in subepithelial invasion of lung cancer

BACKGROUND AND OBJECTIVE

Mucosal irregularity and hypervascularity associated with primary lung cancer in large airways are observed by bronchoscopy. The aim of this study was to evaluate microcirculation at subepithelial invasion sites of lung cancer.

METHODS AND PATIENTS

Between July 2001 and June 2007, 12 patients who had subepithelial invasion sites of lung cancer in the large airways (aged 52 to 74 years, 12 males) were enrolled into this study. They were 6 patients with adenocarcinoma, 4 patients with squamous cell carcinoma, and 2 patients with small cell carcinoma. We compared 12 control subjects without endobronchial abnormality (aged 51 to 83 years, 9 males and 3 females). The patients underwent conventional bronchoscopy and subsequent high magnification bronchovideoscopy with the conventional imaging and the narrow band imaging (NBI). For evaluating microcirculation of subepithelial invasion, hemoglobin index was calculated.

RESULTS

In high magnification view, aberrant microvessels and/or irregular mucosal thickening were observed at subepithelial invasion sites of lung cancer. Irregularly enlarged microvessels were increased and formed an aberrant microvessel network on the surface of irregular mucosa. The diameter of aberrant microvessels was significantly increased compared to normal microvessels. By switching to NBI, the aberrant microvessels were more clearly visualized. The levels of hemoglobin index were significantly higher in subepithelial invasion sites of lung cancer compared to normal mucosa.

CONCLUSION

In subepithelial invasion of lung cancer, aberrant microvessels are thought to be characteristic and subepithelial microcirculation may be increased.

Analysis of motor function modulated by cholinergic neurons in planarian Dugesia japonica

Recent studies of the freshwater planarian Dugesia japonica have revealed fundamental mechanisms and unique aspects of neuroscience and neuroregeneration. Here, we identified the gene for planarian choline acetyltransferase (Djchat), which is essential for acetylcholine (ACh) biosynthesis. Immunofluorescence studies using anti-Dugesia japonica ChAT (DjChAT) antibody revealed that cholinergic neurons are widely distributed in the planarian nervous system, including the brain, ventral nerve cords, optic nerves, and pharyngeal nerve plexus. In order to investigate the function of cholinergic neurons in planarians, we used both pharmacological and RNA interference (RNAi) approaches. Administration of physostigmine (an acetylcholinesterase inhibitor) clearly elevated the amount of ACh, and then induced sudden muscle contraction behavior in a concentration-dependent manner. In addition, we found that pretreatment with tubocurarine (a muscle nicotinic ACh receptor antagonist) or atropine (a non-selective muscarinic ACh receptor antagonist), but not pretreatment with mecamylamine (a neural nicotinic ACh receptor antagonist), significantly extended the latency time for physostigmine-induced contraction behavior, suggesting that muscle nicotinic ACh receptors and muscarinic ACh receptors contribute to physostigmine-induced contraction behavior. We also confirmed that ACh biosynthesis ability and DjChAT-immunoreactivity were eliminated in Djchat(RNAi) planarians. Moreover, the decrease of the level of ACh induced by Djchat(RNAi) caused extension of the latency time for contraction behavior. Our findings support the possibility that the cholinergic functions of planarians are similar to those of vertebrates, suggesting that planarians are simple but useful model organisms for getting insight into the cholinergic nervous system in higher animals.

Serological surveillance of influenza A virus infection in swine populations in Fujian province, China: no evidence of naturally occurring H5N1 infection in pigs

Several highly pathogenic H5N1 avian influenza viruses were isolated from swine populations in Fujian Province, China, since 2001. Because it is thought that H5N1 infection in pigs might result in virus adaptation to humans, we surveyed swine populations in Fujian Province in 2004 and 2007 for serological evidence of the infection. Twenty-five pig farms covering all nine administrative districts of Fujian Province were sampled and a total of 1407 serum specimens were collected. The haemagglutination inhibition (HI) tests revealed no evidence of H5 infection and only a few cases of H9 infection. The negative results for H5 infection were further verified by micro-neutralization tests. By contrast, H1 influenza virus infections were prevalent in swine in both surveys according to the results of enzyme-linked immunosorbent assay (ELISA). The H3 infection rate was reduced dramatically in 2007 compared with 2004, when examined by HI and ELISA. In summary, the results imply that the swine populations in Fujian Province had not been affected greatly by the H5N1 avian influenza virus, given that there is no serological evidence that H5N1 influenza virus has infected the pig populations. The reported isolates represent only sporadic cases.

Management for patients with de novo or recurrent tumors in the residual kidney after surgery for nonfamilial bilateral renal cell carcinoma

The tumor de novo in the residual kidney after surgery for nonfamilial bilateral renal cell carcinoma (RCC) is problematic. We reviewed 5 patients who experienced such a situation. Three patients had had metachronous bilateral RCC, treated with radical nephrectomy in one kidney and nephron-sparing surgery (NSS) in the other. Two patients had had synchronous disease; one patient had received radical nephrectomy and NSS, and the other bilateral NSS. The 5 patients had another solid mass/de novo tumor in the residual kidney 16-88 (mean 46.8) months after surgery. For the tumor de novo in earlier years (1992-1999), one patient underwent surgery and hemodialysis, and the other selected a conservative observation. In recent years (2000-2007), one patient was conservatively observed; the remaining 2 received computerized-tomography-guided radiofrequency ablation, and the local tumors were well controlled postoperatively for 20 and 12 months with their renal function unimpaired. Ablative techniques can potentially strike a balance between oncological and nephrological outcomes in patients with sporadic multiple RCC, successful management of which was difficult previously.

Characteristic Genotypes of Vascular Endothelial Growth Factor are Susceptible to Ascites in Patients with Cirrhosis

This study was designed to investigate whether different vascular endothelial growth factor (VEGF) genotypes are associated with ascites formation in cirrhotic patients. Seventy cirrhotic patients were included in the study: 25 cirrhotic patients with ascites and 45 cirrhotic patients without ascites. Patient characteristics were investigated and compared between the two groups. With regard to VEGF genotype, 42 patients were C/C and 28 patients were T/T or C/T. The genotypes T/T or C/T were observed in 23 cases (51%) among the non-ascites group, but in only five cases (20%) among the ascites group. Serum levels of albumin and creatinine, and the VEGF genotypes were significantly different between the two groups. Multiple regression analysis showed that serum levels of creatinine and the VEGF genotypes were significantly correlated with ascites formation. Thus, it can be concluded that VEGF genotyping might be a valuable susceptibility marker for ascites formation in cirrhotic patients.

Quantitative estimation of exchange interaction energy using two-electron vertical double quantum dots

We use Pauli-spin blockade in two-electron vertical double quantum dots to quantitatively estimate the exchange energy J in a wide range of interdot level detuning Delta and fully compare it with calculations. Pauli-spin blockade is lifted via a singlet- (S-)triplet (T) transition mediated by hyperfine coupling, which abruptly occurs in our devices when the S-T transition energy or J is compensated by the Zeeman energy. We use this feature to derive J depending on Delta between the S-S and T-T resonances. The obtained J versus Delta including the resonance effect is perfectly reproduced by Hubbard model calculations.

Membrane formation mechanism of cross-linked polyurea microcapsules by phase separation method

This research was conducted to clarify the membrane formation mechanism of cross-linked polyurea microcapsules by phase separation method, especially the role of polymeric surfactant, such as poly(ethylene-alt-maleic anhydride) (poly(E-MA)) at the interface of O/W emulsion. It was found that poly(E-MA) was necessary for the formation of cross-linked polyurea membrane. The addition of sodium dodecyl sulphate (SDS) prohibited the membrane formation reaction at the interface, even in the case of poly(E-MA) concentration enough for polymeric microcapsule formation. From the results in this study, poly(E-MA) was found to be adsorbed on the O/W emulsion and provide the reaction site for the membrane formation of polymeric microcapsules.

Nitric oxide-cyclic guanosine monophosphate signaling in the local circuit of the cricket abdominal nervous system

The distribution of potential nitric oxide (NO) donor neurons and NO-responsive target neurons was revealed in the terminal abdominal ganglion (TAG) of the cricket. The expression of nitric oxide synthase (NOS) in the nervous system was examined by Western blotting using universal nitric oxide synthase (uNOS) antibody that gave about a 130 kDa protein band. Immunohistochemistry using the uNOS antibody detected neurons whose cell bodies are located at the lateral region of the TAG. These neurons expanded their neuronal branches into the dorsal-median region or the dorsal-lateral region of the TAG. NADPH-diaphorase histochemistry was performed to confirm the distribution of NOS-containing neurons. The distributions of cell bodies and stained neuronal branches were similar to those revealed by uNOS immunohistochemistry. NO-induced cGMP immunohistochemistry was performed to reveal NO-responsive target neurons. Most of the cell bodies stained by immunohistochemistry appeared at the dorsal side of the TAG. At the dorsal-median region, some unpaired neuronal cell bodies were strongly stained. Some efferent neurons whose axon innervate into each nerve root were strongly stained. The generation of NO in the TAG was detected by NO electrode. We found that NO is generally produced to maintain a basal concentration of 70 nM. Hemoglobin scavenged released NO from the ganglion. The concentration of NO was partly recovered when hemoglobin was replaced by normal saline. Application of 10 microM L-arginine that is a substrate of NOS increased NO release by approximately 10 nM. Furthermore, an excitatory neurotransmitter acetylcholine (ACh) also increased NO generation by approximately 40-50 nM in concentration in addition to the basal level of 70 nM. Optical imaging with fluorescent NO-indicator demonstrated that ACh-induced enhancement of NO release was transiently observed in the outer-edge region of TAG, where cell bodies of NOS-immunoreactive neurons were located. These results suggest that ACh accelerates NO production via neuronal events activated by ACh in the TAG.

Steady state characteristics of acclimated hydrogenotrophic methanogens on inorganic substrate in continuous chemostat reactors

A Monod model has been used to describe the steady state characteristics of the acclimated mesophilic hydrogenotrophic methanogens in experimental chemostat reactors. The bacteria were fed with mineral salts and specific trace metals and a H(2)/CO(2) supply was used as a single limited substrate. Under steady state conditions, the growth yield (Y(CH4)) reached 11.66 g cells per mmol of H(2)/CO(2) consumed. The daily cells generation average was 5.67 x 10(11), 5.25 x 10(11), 4.2 x 10(11) and 2.1 x 10(11) cells/l-culture for the dilutions 0.071/d, 0.083/d, 0.1/d and 0.125/d, respectively. The maximum specific growth rate (mu(max)) and the Monod half-saturation coefficient (K(S)) were 0.15/d and 0.82 g/L, respectively. Using these results, the reactor performance was simulated. During the steady state, the simulation predicts the dependence of the H(2)/CO(2) concentration (S) and the cell concentration (X) on the dilution rate. The model fitted the experimental data well and was able to yield a maximum methanogenic activity of 0.24 L CH(4)/g VSS.d. The dilution rate was estimated to be 0.1/d. At the dilution rate of 0.14/d, the exponential cells washout was achieved.

An aspergillotic aneurysm of the internal carotid artery following allogeneic bone marrow transplantation: successful management with catheter coil embolization and long-term antifungal agents

We report a case of a mycotic aneurysm of the internal carotid artery and cerebral hemorrhagic infarction resulting from Aspergillus middle ear infection in a patient with severe aplastic anemia who received unrelated bone marrow transplantation. Although a mycotic aneurysm is a rare complication, and most often fatal, the patient was successfully treated with catheter coil embolization of the internal carotid artery and long-term systemic antifungal therapy. This case emphasizes the need for the rapid diagnosis of potential fungal involvement of the vascular system and suggests the necessity for aggressive treatment, such as with the modality illustrated in this case.

A ketolide antibiotic, telithromycin, inhibits vascular adrenergic neurotransmission in the rat mesenteric vascular bed

BACKGROUND AND PURPOSE

A ketolide antibiotic, telithromycin, has side effects including temporary loss of consciousness in clinical use, but the underlying mechanisms remain unclear. This study investigated the effects of telithromycin on perivascular nerve function in rat mesenteric arteries, in comparison with those of macrolide (erythromycin and clarithromycin) and new quinolone antibiotics (levofloxacin and gatifloxacin).

EXPERIMENTAL APPROACH

In vitro, vascular responses and release of noradrenaline induced by periarterial nerve stimulation (PNS) of rat perfused mesenteric vascular beds were measured in the presence of each antibiotic. In vivo blood pressure measurement was performed in Wistar rats.

KEY RESULTS

In mesenteric preparations with resting tone, telithromycin (10 nM-10 microM) markedly inhibited PNS (4-12 Hz)-induced adrenergic nerve- and exogenous noradrenaline-mediated vasoconstriction, whereas the other antibiotics slightly inhibited PNS-induced responses without affecting noradrenaline-induced responses. Telithromycin significantly reduced PNS (12 Hz)-evoked noradrenaline release in the perfusate. In pre-constricted preparations with or without endothelium, telithromycin (0.1 nM-10 microM) caused a concentration-dependent vasodilation. Telithromycin (10 nM) inhibited calcium-induced vasoconstriction in high KCl and calcium-free medium. None of the antibiotics used affected PNS (0.5-2 Hz)-induced calcitonin gene-related peptide (CGRP) nerve- and exogenous CGRP-mediated vasodilation. Intravenous injection of telithromycin significantly lowered blood pressure in anaesthetized rats.

CONCLUSIONS AND IMPLICATIONS

These results suggest that telithromycin causes not only strong inhibition of perivascular adrenergic neurotransmission but also a vasodilator action in mesenteric vascular beds and hypotension. It is thus possible that telithromycin increases visceral blood flow, consequently reducing cerebral blood flow and resulting in a temporary loss of consciousness.

Characterization of non-linear relationship between total and unbound serum concentrations of valproic acid in epileptic children

OBJECTIVE

To establish a regression equation to properly estimate the unbound serum concentration of valproic acid (VPA) from its total serum concentration; the relationship between total and unbound serum VPA concentrations was retrospectively characterized.

METHODS

Data were obtained from the clinical examination records that were routinely archived during therapeutic drug monitoring. The screening encompassed 342 records of 108 paediatric patients whose total and unbound VPA concentrations had been determined. The relationship between total and unbound VPA concentrations was characterized according to the Langmuir equation by taking account of inter-individual variability with the nonmem program.

RESULTS

The total VPA concentration (C(t)) in the screened patients ranged from 5.5 to 179.8 microg/mL, and the unbound VPA concentration (C(f)) increased in a non-linear manner as the total VPA concentration increased. Taking account of the effects of antiepileptics concurrently administered, the VPA dissociation constant (K(d)) and maximum binding site concentration (B(m)) were 7.8 +/- 0.7 and 130 +/- 4.5 microg/mL respectively, for the regression equation, C(t) = C(f) + B(m) x C(f)/(K(d) + C(f)). An alteration in the unbound concentration was seen in patients who were treated with the combination of VPA and ethosuximide and in those who received two additional antiepileptics.

CONCLUSIONS

A regression equation for estimation of the unbound VPA concentration, based on total VPA concentration collected during routine therapeutic drug monitoring was established. Use of two additional antiepileptics and ethosuximide treatment was considered as potential factors affecting unbound VPA concentration.

Endothelium removal augments endothelium-independent vasodilatation in rat mesenteric vascular bed

BACKGROUND AND PURPOSE

The vascular endothelium regulates vascular tone by releasing various endothelium-derived vasoactive substances to counteract excess vascular response. We investigated whether the vascular endothelium regulates vasodilatation via released endothelium-derived contracting factors (EDCFs), by examining the effect of endothelium removal on responses to periarterial nerve stimulation (PNS) and various vasodilator agents.

EXPERIMENTAL APPROACH

The rat mesenteric vascular bed was perfused with Krebs solution. Vasodilator responses to PNS and 5 min perfusion of vasodilator agents in preparations with endothelium were compared with those in the same preparations without endothelium. The endothelium was removed by 30 s perfusion with sodium deoxycholate.

KEY RESULTS

Endothelium removal significantly augmented vasodilator responses to PNS and calcitonin gene-related peptide (CGRP), isoprenaline (beta-adrenoceptor agonist), SNP and 8-bromo-cGMP (8-Br-cGMP; cGMP analogue) but not BAY41-2272 (soluble guanylate cyclase activator). The augmentation of SNP-induced vasodilatation after denudation was much greater than that of CGRP- or isoprenaline-induced vasodilatation. In the preparations with an intact endothelium, L-NAME (nitric oxide synthase inhibitor) significantly augmented vasodilator responses to PNS and CGRP, isoprenaline, SNP and 8-Br-cGMP, but not BAY41-2272. Indomethacin (cyclooxygenase inhibitor) and seratrodast (thromboxane A(2) receptor antagonist), but not phosphoramidon (endothelin-1-converting enzyme inhibitor) or BQ-123 (selective endothelin type A receptor antagonists), significantly augmented vasodilator responses to PNS and CGRP, isoprenaline, SNP and BAY41-2272.

CONCLUSION AND IMPLICATION

These results suggest that the endothelium in rat mesenteric arteries regulates and maintains vascular tone via counteracting not only vasoconstriction through releasing endothelium-derived relaxing factors, but also vasodilatation, in part by releasing an EDCF, thromboxane A(2).

Primary solitary fibrous tumor (SFT) in the retroperitoneum

BACKGROUND

Solitary fibrous tumor (SFT) is an infrequent but distinct neoplasm, which generally arises from submesothelial connective tissue in the pleura. SFT is rarely recognized in extrathoracic sites, and histologically identical conditions have also been reported in the retroperitoneum, although their pathophysiology has not been extensively investigated.

METHODS

We present four cases of primary SFT in the retroperitoneum, and review 37 similar cases in the previous literature.

RESULTS

About 40% of patients were asymptomatic, and 19.2% and 15.4% presented with an abdominal mass and urinary symptoms, respectively. The tumor size ranged between 2 and 26 (mean 9.1) cm. Sixty-three percent of tumors showed nonspecific development with haphazard distribution of bland short spindle or polygonal cells with or without collagenous bundles and stromal hyalinization. In 22.0%, hemangiopericytomatous appearance was seen. About 15% of cases showed histologically malignant characteristics. The tumor cells were immunoreactive for vimentin in all cases, CD34 in 91% and Bcl-2 in 86%. All tumors were excised, and in 85.4% of cases, tumors did not recur postoperatively for 6 to 48 months. No significant difference was found between the recurrence rate of histologically benign and malignant cases. Cases positive for both CD34 and Bcl-2 had no recurrence.

CONCLUSIONS

The identification of SFT in the retroperitoneum is of importance because histopathological indicators of malignancy are not necessarily associated with clinical malignant potential in many cases of retroperitoneal SFT. Retroperitoneal SFT showing typical pathological features with expression of CD34 and Bcl-2 is associated with a favorable outcome following excision.

Delta 9-tetrahydrocannabinol-induced catalepsy-like immobilization is mediated by decreased 5-HT neurotransmission in the nucleus accumbens due to the action of glutamate-containing neurons

Delta(9)-tetrahydrocannabinol (THC) has been reported to induce catalepsy-like immobilization, but the mechanism underlying this effect remains unclear. In the present study, in order to fully understand the neural circuits involved, we determined the brain sites involved in the immobilization effect in rats. THC dose-dependently induced catalepsy-like immobilization. THC-induced catalepsy-like immobilization is mechanistically different from that induced by haloperidol (HPD), because unlike HPD-induced catalepsy, animals with THC-induced catalepsy became normal again following sound and air-puff stimuli. THC-induced catalepsy was reversed by SR141716, a selective cannabinoid CB(1) receptor antagonist. Moreover, THC-induced catalepsy was abolished by lesions in the nucleus accumbens (NAc) and central amygdala (ACE) regions. On the other hand, HPD-induced catalepsy was suppressed by lesions in the caudate putamen (CP), substantia nigra (SN), globus pallidus (GP), ACE and lateral hypothalamus (LH) regions. Bilateral microinjection of THC into the NAc region induced catalepsy-like immobilization. This THC-induced catalepsy was inhibited by serotonergic drugs such as 5-hydroxy-L-tryptophan (5-HTP), a 5-HT precursor, and 5-methoxy-N,N-dimethyltryptamine (5-MeODMT), a 5-HT receptor agonist, as well as by anti-glutamatergic drugs such as MK-801 and amantadine, an N-methyl-d-aspartate (NMDA) receptor antagonist. THC significantly decreased 5-HT and glutamate release in the NAc, as shown by in vivo microdialysis. SR141716 reversed and MK-801 inhibited this decrease in 5-HT and glutamate release. These findings suggest that the THC-induced catalepsy is mechanistically different from HPD-induced catalepsy and that the catalepsy-like immobilization induced by THC is mediated by decreased 5-HT neurotransmission in the nucleus accumbens due to the action of glutamate-containing neurons.

Alpha3beta4-nicotinic receptors mediate adrenergic nerve- and peptidergic (CGRP) nerve-dependent vasodilation induced by nicotine in rat mesenteric arteries

BACKGROUND AND PURPOSE

Previous studies demonstrated that nicotine-induced endothelium-independent vasodilation is mediated by perivascular adrenergic nerves and nerves releasing calcitonin gene-related peptide (CGRPergic nerves). We characterized the nicotinic acetylcholine (ACh) receptor subtype underlying the vasodilation in response to nicotine in rat mesenteric arteries.

EXPERIMENTAL APPROACH

Rat mesenteric vascular beds without endothelium were contracted by perfusion with Krebs solution containing methoxamine and the perfusion pressure was measured with a pressure transducer.

KEY RESULTS

Perfusion of nicotine (1-100 microM) for 1 min caused a concentration-dependent decrease in perfusion pressure due to vasodilation. Perfusion of (+/-)-epibatidine (1-100 nM) (non-selective agonist) or (-)-cytisine (1-100 microM) (partial agonist for nicotinic beta2 subtype and full agonist for nicotinic beta4 subtype) induced vasodilation in a concentration-dependent manner. Vasodilation induced by nicotine, (-)-cytisine- and (+/-)-epibatidine was markedly attenuated by guanethidine (5 microM) and pretreatment with capsaicin (1 microM). Mecamylamine (relatively selective antagonist for alpha3beta4 subtype), but not dihydro-beta-erythroidine (selective antagonist for alpha4beta2 subtype) or alpha-bungarotoxin (selective antagonist for alpha7 subtype), markedly inhibited nicotine-induced vasodilation. Nicotine-induced vasodilation was inhibited by methyllycaconitine at high concentrations (>1 microM), which non-selectively antagonize nicotinic receptors, while a low concentration of 10 nM, which selectively antagonizes alpha7 subtype, had no effect. (-)-Cytisine and (+/-)-epibatidine-induced vasodilation were abolished by mecamylamine.

CONCLUSION AND IMPLICATIONS

These results suggest that the nicotinic alpha3beta4 receptor subtype, but not the alpha7 and alpha4beta2 subtypes, is responsible for the vasodilation in rat mesenteric arteries induced by nicotine- and nicotinic ACh receptor agonists through stimulation of adrenergic and CGRPergic perivascular nerves.

Adrenomedullin facilitates reinnervation of phenol-injured perivascular nerves in the rat mesenteric resistance artery

Our previous report showed that innervation of calcitonin gene-related peptide (CGRP)- and neuropeptide Y (NPY)-containing nerves in rat mesenteric resistance arteries was markedly reduced by topical application of phenol, and that nerve growth factor (NGF) facilitates the reinnervation of both nerves. We also demonstrated that a CGRP superfamily peptide, adrenomedullin, is distributed in perivascular nerves of rat mesenteric resistance arteries. In the present study, we investigated the influence of adrenomedullin on the reinnervation of mesenteric perivascular nerves following topical phenol treatment. Under pentobarbital-Na anesthesia, 8-week-old Wistar rats underwent in vivo topical application of phenol (10% phenol in 90% ethanol) to the superior mesenteric artery proximal to the bifurcation of the abdominal aorta. After the treatment, the animals were subjected to immunohistochemistry of the third branch of small arteries proximal to the intestine and to vascular responsiveness testing on day 7. Topical phenol treatment caused marked reduction of the density of NPY-like immunoreactive (LI)- and CGRP-LI nerve fibers in the arteries. Adrenomedullin (360 or 1000 ng/h) or NGF (250 ng/h), which was administered intraperitoneally for 7 days using an osmotic mini-pump immediately after topical phenol treatment, significantly increased the density of CGRP-LI- and NPY-LI nerve fibers compared with saline. Treatment with adrenomedullin (1000 ng/h) or NGF restored adrenergic nerve-mediated vasoconstriction and CGRP nerve-mediated vasodilation in the perfused mesenteric artery treated topically with phenol. These results suggest that adrenomedullin, like NGF, has a facilitatory effect on the reinnervation of perivascular nerves.

Outcomes of locally advanced prostate cancer: a single institution study of 209 patients in Japan

AIM

To investigate the outcomes for Asian populations with locally advanced/clinical stage III prostate cancer (PCa) treated with currently prevailing modalities.

METHODS

We reviewed the record of 209 patients with clinical stage III PCa, who were treated at Niigata Cancer Center Hospital between 1992 and 2003. Treatment options included hormone therapy-combined radical prostatectomy (RP+HT), hormone therapy-combined external beam irradiation (EBRT+HT) and primary hormone therapy (PHT).

RESULTS

The 5- and 10-year overall survival rates were 80.3% and 46.1% in all cohorts, respectively. The survival rates were 87.3% and 66.5% in the RP+HT group, 94.9% and 70.0% in the EBRT+HT group and 66.1% and 17.2% in the PHT group, respectively. A significant survival advantage was found in the EBRT+HT group compared with that in the PHT group (P < 0.0001). Also, the RP+HT group had better survival than the PHT group (P = 0.0107). The 5- and 10-year disease-specific survival rates for all cases were 92.5% and 80.0%, respectively. They were 93.8% and 71.4% in the RP+HT group, 96.6% and 93.6% in the EBRT+HT group and 88.6% and 62.3% in the PHT group, respectively. A survival advantage was found in the EBRT+HT group compared with the PHT group (P = 0.029). No significant difference was found in disease-specific survival between the EBRT+HT and RP+HT groups or between the RP+HT and PHT groups.

CONCLUSION

Although our findings indicate that radiotherapy plus HT has a survival advantage in this stage of PCa, we recommend therapies that take into account the patients'social and medical conditions for Asian men with clinical stage III PCa.

[Significance of re-measurement of prostate specific antigen before prostate biopsy]

To examine the natural change of prostate-specific antigen (PSA), we compared two PSA values, the first value with which we decided to perform prostate biopsy and the value obtained by remeasurement just before biopsy. To exclude cases with extremely high PSA, we examined 288 cases in which PSA was less than 50 ng/ml for comparison. Of the 288 cases, 93 were diagnosed with prostate cancer (CaP). The interval between the two PSA measurements was 1-90 days (average of 31.4 days). The first and second values were an average of 13.0 and 11.7 ng/ml, respectively, and the second value was significantly lower than the first value. When we divided them into CaP cases and non-CaPthe two cases, a significant difference between PSA values was found only in the non-CaP cases. Moreover, in the non-CaP cases with some clinical symptoms, the difference in PSA was marked between the first and second values, which averaged 11.2 and 9.2 ng/ml, respectively. When we decide to perform a biopsy, we should recognize that PSA sometimes is lower on re-measurement. Particularly in symptomatic cases, it is worth re-measuring PSA, which may save unnecessary biopsies.

Effect of immunotherapy and spleen preservation on immunological function in patients with gastric cancer

Splenectomy is often performed in patients who undergo total gastrectomy for cancer of the upper stomach. Although splenectomy facilitates lymph node dissection of the splenic hilum and recent reports advocate spleen preservation, the role of the spleen is not fully elucidated in gastric cancer treatment. This prospective randomized study was performed to evaluate the role of the spleen in immunological function in gastric cancer patients who underwent total gastrectomy and received postoperative immunochemotherapy. Forty-five patients with gastric cancer were randomly allocated to four groups: 1. splenectomy without immunotherapy (OK-432 administration), 2. splenectomy with immunotherapy, 3. spleen preservation without immunotherapy, 4. spleen preservation with immunotherapy. Postoperative immunological function of these patients was compared among the four groups. NK cell activity of the peripheral blood lymphocytes (PBL) in spleen-preserved patients who received immunotherapy was significantly higher for 24 weeks after surgery than that of the splenectomized patients with and without OK-432 administration. IL-2 production of PBL in spleen-preserved patients with immunotherapy was significantly higher between 4 and 24 weeks after surgery compared with that of the splenectomized patients without immunotherapy. The results suggest that spleen preservation might be beneficial in patients with less advanced gastric cancer who receive postoperative immunochemotherapy after total gastrectomy.

Total and free prostate-specific antigen indexes in prostate cancer screening: value and limitation for Japanese populations

AIM

To assess the efficacy and limitation of free/total prostate-specific antigen ratio (f/tPSA) at a single institution in Japan, focusing on the avoidance of pointless prostate biopsies.

METHODS

In total, 631 men between 44 and 93 years old (mean 69.8 years) with elevated PSA underwent power-Doppler ultrasoundgraphy-guided transrectal 10-core prostate biopsies at Niigata Cancer Center Hospital, and their histological features were investigated with total PSA (tPSA) and f/tPSA.

RESULTS

PCa was detected in 126 of 134 patients (94.3%) with tPSA of 26 ng/mL or higher. The detection rate was 59.4% for tPSA of 21-25 ng/mL, followed by 39.2% for 16-20 ng/mL, 30.0% for 11-15 ng/mL, 20.0% for 4.1-10 ng/mL and 7.6% for = or <4.0 ng/mL. f/tPSA of the PCa group was significantly lower than that of non-malignamt disorders in any tPSA ranges (mean 0.122 vs. 0.160, P<0.001). Receiver-operating characteristics analyses showed that f/tPSA (AUC:0.664) performed more valuably than tPSA (AUC:0.559) in patients with tPSA between 3.0-10 ng/mL (P<0.01). Although f/tPSA of 0.250 for the cut-off value might miss 1.8% PCa patients, it potentially spares 9.2% of unnecessary biopsies.

CONCLUSION

f/tPSA is more valuable compared with tPSA alone for the prediction of the occurrence of PCa. We recommend 0.250 as the cut-off value for f/tPSA in PCa screening for Asian men having so-called grey-zone tPSA.

Can PET/CT substitute for bone scintigraphy in assessment of bone metastases in lung cancer patients?

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Background: Bone is a frequent site of lung cancer metastasis. However, false positive lesions detected by conventional bone scintigraphy often become problematic. We compared the efficacy of whole-body [18F]-2-Fluoro-2-deoxy- D- glucose PET/CT imaging and conventional bone scintigraphy for assessment of bone lesions in lung cancer patients on an individual patient basis. Methods: The study population comprised 106 consecutive patients with suspected or proven lung cancer (73 men and 33 women; age range: 40 to 85 years) who underwent both whole-body PET/CT imaging and conventional bone scintigraphy using 740 MBq of Tc-99m hydroxymethylene diphosphonate for cancer staging. Diagnostic radiologists interpreted and assessed all images on a patient-by-patient basis. Clinical information and the findings of follow-up imaging studies were used as the gold standard for the identification of bone metastases. Results: On the basis of the gold standard, 11 of the 106 patients were identified as having bone metastases. Bone scintigraphy showed a sensitivity of 67% (7/11) while that of PET/CT was 100% (11/11) for detection of bone metastases. Seven of these 11 patients were deemed positive based on both bone scintigraphy and PET/CT. Bone metastases not identified on bone scintigraphy were detected on PET/CT in another four patients. For 39 of 95 patients without bone metastases, the assessment was false-positive for bone scintigraphy but negative for PET/CT. In two of the 39 patients, CT images of PET/CT could identify a benign fracture causing a false positive finding for bone scintigraphy. Conclusions: PET/CT might actually substitute for bone scintigraphy in lung cancer patients because of its superior ability to detect unsuspected bone metastases and to differentiate bone metastases from false positive lesions detected by bone scintigraphy.

No significant financial relationships to disclose.

[Clinical analysis of 1,000 patients with prostate cancer]

OBJECTIVES

Treatment outcomes for prostate cancer in our hospital were reported.

MATERIALS AND METHODS

We analyzed 1,009 patients with prostate cancer treated at Niigata Cancer Hospital between 1983 and 2003.

RESULTS

As for the clinical stage, 20 cases belonged to Stage I, 367 cases to Stage II, 269 cases to Stage III and 353 cases to Stage IV. The overall 5-year survival rate of the all 1,009 cases was 59.0%, comprising 78.2% for stage I, 82.0% for Stage II, 76.0% for Stage III and 30.0% for Stage IV cases. Disease-specific 5-year survival rates for Stage I, II, III and IV were 100%, 96.8%, 89.3% and 41.1% respectively. In Stage III patients, the radiotherapy (with endocrine therapy) group showed longer cause-specific survival than the endocrine therapy group (p = 0.0056).

CONCLUSIONS

Our result suggest that the radiotherapy with endocrine therapy is useful for Stage III prostate cancer.

Comparison of MR images and histochemical localization of intra-arterially administered microglia surrounding beta-amyloid deposits in the rat brain

The therapeutic use of microglial cells has recently received some attention for the treatment of Alzheimer disease (AD), but few non-invasive techniques exist for monitoring the cells after administration. Here we present a magnetic resonance imaging (MRI) technique for tracking microglia injected intra-arterially in vivo. We micro-injected Abeta42 into the left hippocampus and saline into the right hippocampus of rats. We then administered microglia, which were labeled with enhanced green fluorescent protein (EGFP) gene and Resovist, into the carotid artery. After monitoring exogenously administered microglia using MRI, we compared the MR images and the histochemical localization of administered microglia. MRI revealed clear signal changes attributable to Resovist-containing microglia in Abeta-injected areas. Histochemistry demonstrated that EGFP-positive microglia accumulated around Abeta deposits and internalized the peptide. This study demonstrates the usefulness of MRI for non-invasive monitoring of exogenous microglia, and suggests a promising future for microglia/macrophages as therapeutic tools for AD.

[Prognosis of prostate cancer with elevated prostatic acid phosphatase]

To evaluate the significance of prostatic acid phosphatase (PAP), we analyzed 1,029 prostate cancer patients who were treated at the Niigata Cancer Center. We classified clinically localized prostate cancer with elevated PAP as stage DO. When stage DO was not taken into acount, the 5-year cause-specific survival rate for stage A, B, C and D was 94.7, 97.9, 87.7 and 42.4%, respectively. Taking stage DO into account, the cause-specific survival curve for stage DO patients was similar to those for stage B,C patients. The 5-year cause-specific survival rate for stage DO was 92.2% considering above 3 ng/ml as elevated PAP. A significant correlation was found between PAP and cause-specific survival for all cases but no correlation was found for non-metastatic disease patients. The significance of PAP in the staging of prostate cancer is limited.