Functional analysis of thermo-sensitive TRPV1 in an aquatic vertebrate, masu salmon (Oncorhynchus masou ishikawae)

Transient receptor potential vanilloid 1 (TRPV1) is mainly expressed in nociceptive primary sensory neurons and acts as a sensor for heat and capsaicin. The functional properties of TRPV1 have been reported to vary among species and, in some cases, the species difference in its thermal sensitivity is likely to be associated with thermal habitat conditions. To clarify the functional properties and physiological roles of TRPV1 in aquatic vertebrates, we examined the temperature and chemical sensitivities of TRPV1 in masu salmon (Oncorhynchus masou ishikawae, Om) belonging to a family of salmonids that generally prefer cool environments. First, behavioral experiments were conducted using a video tracking system. Application of capsaicin, a TRPV1 agonist, induced locomotor activities in juvenile Om. Increasing the ambient temperature also elicited locomotor activity potentiated by capsaicin. RT-PCR revealed TRPV1 expression in gills as well as spinal cord. Next, electrophysiological analyses of OmTRPV1 were performed using a two-electrode voltage-clamp technique with a Xenopus oocyte expression system. Heat stimulation evoked an inward current in heterologously expressed OmTRPV1. In addition, capsaicin produced current responses in OmTRPV1-expressing oocytes, but higher concentrations were needed for its activation compared to the mammalian orthologues. These results indicate that Om senses environmental stimuli (heat and capsaicin) through the activation of TRPV1, and this channel may play important roles in avoiding environments disadvantageous for survival in aquatic vertebrates.

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Capsaicin evoked behavioral responses of Oncorhynchus masou ishikawae (Om).

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The behavioral response to heat was potentiated by capsaicin.

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Heterologously expressed OmTRPV1 was activated by heat and capsaicin.

Reduction of extracellular sodium evokes nociceptive behaviors in the chicken via activation of TRPV1

Transient receptor potential vanilloid 1 (TRPV1), a non-selective cation channel, is mainly expressed in nociceptive primary sensory neurons. Sensitivity of TRPV1 to several stimuli is known to vary among species, specifically, the avian orthologue is nearly insensitive to capsaicin. Extracellular sodium ions ([Na⁺]_o) regulate TRPV1 activity in mammals, but their regulatory role on chicken TRPV1 (cTRPV1) is unknown. Here, we focused on the actions of capsaicin and low [Na⁺]_o on cTRPV1 activity. In chicken dorsal root ganglion (cDRG) neurons, capsaicin elicited [Ca²⁺]_i increases, but its effective concentration was much higher than those in mammals. Low [Na⁺]_o evoked [Ca²⁺]_i increases in cDRG neurons in a decreasing [Na⁺]_o-dependent manner and the complete removal of [Na⁺]_o (0Na) produced maximal effects. The population of 0Na-sensitive neurons was mostly overlapped with those of proton- and capsaicin-sensitive ones. Low [Na⁺]_o synergistically potentiated the capsaicin- and proton-induced TRPV1 activation in cDRG neurons. In HEK293 cells expressing cTRPV1 (cTRPV1-HEK), capsaicin elicited [Ca²⁺]_i increases with an EC₅₀ of 11.8 µM, and low [Na⁺]_o also did. Well-defined mammalian TRPV1 antagonists hardly suppressed cTRPV1 activation by low [Na⁺]_o. 0Na evoked outwardly rectified currents in cTRPV1-HEK. Mutagenesis analyses revealed a possible interaction of [Na⁺]_o with the proton-binding sites of cTRPV1. The administration of capsaicin and 0Na to chick eyes elicited pain-related behaviors. These results suggest that low [Na⁺]_o is capable of activating cTRPV1 in vitro, resulting in pain in vivo. Our data demonstrate that characterization of the cTRPV1 function is important to understand activation mechanisms of TRPV1.

Oral administration of milk-derived phospholipids inhibits penetration of cutaneous nerve fibres into epidermis in a mouse model of acute dry skin

The density of intraepidermal nerve fibres has been shown to be higher in itchy dry skin than in healthy skin, suggesting that epidermal hyperinnervation is at least partly involved in peripheral itch sensitization. We investigated whether oral administration of milk-derived phospholipids (MPLs) would inhibit epidermal hyperinnervation in a mouse model of dry skin. We found that the number of intraepidermal nerve fibres was significantly lower in the MPL group than in the control group. Expression of nerve growth factor (NGF) levels in the epidermis was significantly decreased by oral administration of MPLs, whereas expression of semaphorin (Sema)3A, a nerve repulsion factor, was increased in the MPL group. These results suggest that dietary MPLs attenuate the penetration of nerve fibres into the epidermis by reducing epidermal NGF levels and increasing Sema3A level. Thus, dietary MPLs may have beneficial effects in the prevention and/or alleviation of dry skin-induced itch by reducing intraepidermal nerve fibre density.

Lafutidine, a histamine H2 receptor antagonist with mucosal protective properties, attenuates 5-fluorouracil-induced intestinal mucositis in mice through activation of extrinsic primary afferent neurons

Intestinal mucositis accompanied by severe diarrhea is one of the most common side effects during cancer chemotherapy. Lafutidine, a histamine H2 receptor antagonist with mucosal protective properties via sensory afferent neurons, is used for the treatment of upper gastrointestinal diseases. The present study investigated the effects of lafutidine on 5-fluorouracil (5-FU)-induced intestinal mucositis induced in mice. Male C57BL/6 wild-type (WT), sensory deafferented mice, and transient receptor potential vanilloid subfamily 1 knockout (TRPV1KO) mice were used. Animals were administered 5-FU once daily, while lafutidine and famotidine were administered twice daily for 6 days. Repeated administration of 5-FU caused severe intestinal mucositis, characterized by shortening of villi and destruction of crypts and was accompanied by diarrhea and body weight loss. Daily administration of lafutidine reduced the severity of intestinal mucositis, diarrhea and body weight loss in a dose-dependent manner, while famotidine had no effect on intestinal mucositis. The preventive effects of lafutidine were completely abolished in sensory deafferented and TRPV1-KO mice. Lafutidine significantly suppressed 5-FU-increased MPO activity and inflammatory cytokine expression on day 6, but not apoptosis induction in intestinal crypts on day 1. Lafutidine induced Alcian Blue and PAS-positive mucus production in the small intestine. These findings suggest that lafutidine attenuates 5-FU-induced intestinal mucositis, most likely by increasing mucus production via activation of sensory afferent neurons. Furthermore, intact TRPV1 signaling is essential for the activation of sensory afferent neurons induced by lafutidine. Therefore, lafutidine is more useful than other common antacids for the treatment of intestinal mucositis during cancer chemotherapy.

Impact of antihypertensive medication adherence on blood pressure control in hypertension: the COMFORT study

BACKGROUND

It has not been fully elucidated whether antihypertensive medication adherence affects blood pressure (BP) control in hypertension cases.

AIM

To investigate the association of adherence to antihypertensive drug regimens and BP control using data from the Combination Pill of Losartan Potassium and Hydrochlorothiazide for Improvement of Medication Compliance Trial (COMFORT) study.

DESIGN

An observational analysis from a randomized controlled trial.

METHODS

A total of 203 hypertensive subjects were randomly assigned to a daily regimen of a combination pill (losartan 50 mg/hydrochlorothiazide 12.5 mg) or two pills, an angiotensin II receptor blocker and a thiazide diuretic. Medication adherence calculated based on pill counts and BPs was evaluated at 1, 3 and 6 months after randomization.

RESULTS

The subjects were divided into three groups according to their adherence, i.e. relatively low-adherence (<90%; n = 19), moderate-adherence (90-99%; n = 71) and high-adherence (100%; n = 113) groups. Clinical characteristics of the subjects including BP, sex, randomized treatments and past medical history did not differ significantly among the three groups. Achieved follow-up BPs over the 6-month treatment period, which were adjusted for age, sex, baseline BP and randomized treatment, were significantly higher in the low-adherence group (135/78 mmHg) compared with the high-adherence (130/74 mmHg; P = 0.02/0.02) and the moderate-adherence (128/74 mmHg; P = 0.003/0.02) groups.

CONCLUSION

Low adherence to an antihypertensive-drug regimen was associated with poor BP control.

Neurotropin inhibits the increase in intraepidermal nerve density in the acetone-treated dry-skin mouse model

Epidermal hyperinnervation is considered one cause of sensitization to itch, and is thought to regulated by keratinocyte-derived axonal guidance molecules, including nerve growth factor (NGF) and semaphorin (Sema)3A. Neurotropin (NTP) shows antipruritic effects in allergic disease and is also used for pain relief. Using cultured rat dorsal root ganglion neurones, we previously found that NTP inhibited NGF-induced neurite outgrowth. However, no such inhibitory effect has been shown in vivo. We therefore assessed the effects of intraperitoneal administration of NTP on nerve density and expression of NGF and Sema3A mRNAs in the epidermis of acetone-treated mice showing epidermal hyperinnervation. We found that NTP significantly reduced intraepidermal nerve growth in these acetone-treated mice. NTP significantly upregulated epidermal Sema3A mRNA, but had no effect on expression of epidermal NGF mRNA. These findings indicate that NTP may reduce intraepidermal nerve density by inducing expression of Sema3A in the epidermis.

Cross-sensitization of histamine-independent itch in mouse primary sensory neurons

Overexpression of pruritogens and their precursors may contribute to the sensitization of histamine-dependent and -independent itch-signaling pathways in chronic itch. We presently investigated self- and cross-sensitization of scratching behavior elicited by various pruritogens, and their effects on primary sensory neurons. The MrgprC11 agonist BAM8-22 exhibited self- and reciprocal cross-sensitization of scratching evoked by the protease-activated receptor-2 (PAR-2) agonist SLIGRL. The MrgprA3 agonist chloroquine unidirectionally cross-sensitized BAM8-22-evoked scratching. Histamine unidirectionally cross-sensitized scratching evoked by chloroquine and BAM8-22. SLIGRL unidirectionally cross-sensitized scratching evoked by chloroquine. Dorsal root ganglion (DRG) cells responded to various combinations of pruritogens and algogens. Neither chloroquine, BAM8-22 nor histamine had any effect on responses of DRG cell responses to subsequently applied pruritogens, implying that their behavioral self- and cross-sensitization effects are mediated indirectly. SLIGRL unilaterally cross-sensitized responses of DRG cells to chloroquine and BAM8-22, consistent with the behavioral data. These results indicate that unidirectional cross-sensitization of histamine-independent itch-signaling pathways might occur at a peripheral site through PAR-2. PAR-2 expressed in pruriceptive nerve endings is a potential target to reduce sensitization associated with chronic itch.

H(2)S functions as a nociceptive messenger through transient receptor potential ankyrin 1 (TRPA1) activation

Hydrogen sulfide (H(2)S), an endogenous gasotransmitter, modulates various biological functions, including nociception. It is known that H(2)S causes neurogenic inflammation and elicits hyperalgesia. Here we show that H(2)S activates mouse transient receptor potential ankyrin 1 (TRPA1) channels and elicits acute pain, using TRPA1-gene deficient mice (TRPA1(-/-)) and heterologous expression system. In wild-type mouse sensory neurons, H(2)S increased the intracellular Ca(2+) concentration ([Ca(2+)](i)), which was inhibited by ruthenium red (a nonselective TRP channel blocker) and HC-030031 (a TRPA1 blocker). H(2)S-responsive neurons highly corresponded to TRPA1 agonist-sensitive ones. [Ca(2+)](i) responses to H(2)S were observed in neurons from transient receptor potential vanilloid 1 (TRPV1(-/-)) mice but not from TRPA1(-/-) mice. Heterologously expressed mouse TRPA1, but not mouse TRPV1, was activated by H(2)S. H(2)S-induced [Ca(2+)](i) responses were inhibited by dithiothreitol, a reducing agent. Analyses of the TRPA1 mutant channel revealed that two cysteine residues located in the N-terminal internal domain were responsible for the activation by H(2)S. Intraplantar injection of H(2)S into the mouse hind paw caused acute pain which was significantly less in TRPA1(-/-) mice. The [Ca(2+)](i) responses to H(2)S in sensory neurons and in heterologously expressed channels, and pain-related behavior induced by H(2)S were enhanced under acidic conditions. These results suggest that H(2)S functions as a nociceptive messenger through the activation of TRPA1 channels. TRPA1 may be a therapeutic target for H(2)S-related algesic action, especially under inflammatory conditions.

Neurotropin inhibits both capsaicin-induced substance P release and nerve growth factor-induced neurite outgrowth in cultured rat dorsal root ganglion neurones

BACKGROUND

Neurotropin (NTP), a biological extract from rabbit skin inoculated with vaccinia virus, is an effective analgesic and anti-allergic agent, and has antipruritic effects in various dermatoses including eczema, dermatitis and urticaria. In patients receiving haemodialysis who have pruritus, NTP appears to exert its antipruritic effect by lowering the plasma levels of substance P (SP), but its underlying mechanisms are not fully understood.

AIM

To investigate the antipruritic mechanisms of NTP.

METHODS

The effects of NTP on capsaicin-induced SP release from neonatal rat dorsal root ganglion (DRG) neurones were assessed by measuring SP concentrations in culture media by a competitive ELISA. The effects of NTP on nerve growth factor (NGF)-induced neurite outgrowth were assessed by measuring the length of the longest process of cultured DRG neurones. The neuronal cytotoxicity of NTP was determined using a methylthiazole tetrazolium cytotoxicity assay.

RESULTS

NTP dose-dependently inhibited capsaicin-induced release of SP from cultured DRG neurones, whereas NTP alone had no effect on SP release. Moreover, NTP dose-dependently inhibited NGF-induced neurite outgrowth in cultured DRG neurones. NTP had no observable cytotoxicity.

CONCLUSIONS

These results suggest that NTP exerts its antipruritic effects by inhibiting both SP release and neurite outgrowth of cutaneous sensory nerves.

Decreased plasma C-peptide to insulin molar ratio after oral glucose in elderly subjects

To evaluate the effect of aging on hepatic extraction of insulin, peripheral plasma insulin and C-peptide levels after an oral glucose ingestion were measured in 39 non-obese healthy subjects with normal glucose tolerance test. The subjects were divided into two groups. One age group was below 30 years (n = 17) and another was above 50 years (n = 22). Blood glucose level was significantly higher in elderly subjects than in young at 30 and 60 min, and insulin level was also significantly higher in elderly subjects than in young subjects at 60 min after glucose ingestion. C-peptide response after glucose ingestion was similar in both groups. The molar ratio of C-peptide to insulin after glucose ingestion in elderly subjects was slightly lower than that in young subjects, and the difference between the incremental areas of C-peptide and insulin divided by the incremental area of C-peptide were significantly lower in elderly subjects. These results suggest that hepatic insulin extraction after glucose loading is decreased in elderly subjects and this may partly be responsible for the slightly altered glucose metabolism in elderly subjects with normal glucose tolerance test.

Effect of glucagon on glucose output from bivascularly perfused rat liver

Glucose output was investigated in bivascularly perfused rat liver. Flow rate was 1 ml/min/g from hepatic artery and 2 ml/min/g from portal vein. Basal glucose output (130 +/- 30 microM/min) from bivascularly perfused liver was significantly (p less than 0.02) higher than that (80 +/- 20 microM/min) from usual monovascularly perfused (3 ml/min/g from portal vein) liver. However, glucagon-induced (1 ng/ml) increment in glucose output from bivascularly perfused liver 589 +/- 127 microM/30 min) was not significantly different from that (630 +/- 127 microM/30 min) of monovascularly perfused liver. These results suggest that glucagon-dependent glucose output was similar in monovascularly and bivascularly perfused rat liver, and that arterial blood supply may have some role in glycogenolysis in the perfused rat liver.

Effect of miglitol, an alpha-glucosidase inhibitor, on atherogenic outcomes in balloon-injured diabetic rats

This study investigates the effects of miglitol, an alpha-glucosidase inhibitor, on the development of balloon-injured neointimal thickening in left common carotid artery, and the changes of glucose metabolism and inflammatory responses in Wistar fatty rats, an obese-hyperglycemic animal model, and their littermates, Wistar lean rats. Miglitol was orally administered at 40 mg/100 g of high-fat diet containing 45% kcal as fat to 12-week-old rats for 29 days, and age-matched rats without the agent were used as the respective controls. Balloon catheterization in the left common carotid artery was performed on day 15, and the artery was removed on day 29. Compared with the area ratio of the neointima/media in fatty rats without treatment, those in fatty rats with miglitol and lean rats without treatment were significantly decreased to 80%. The administration of miglitol significantly decreased the levels of plasma glucose, glycoalbumin and high-sensitivity C-reactive protein, and elevated the high-density lipoprotein-cholesterol level in fatty rats. These findings suggest that miglitol could be effective for the suppression of atherogenic outcomes in diabetic Wistar fatty rat, suggesting that the agent may have clinical benefits and contribute to prevent diabetic macroangiopathy.

A multicenter study of leukocytapheresis in rheumatoid arthritis

OBJECTIVE

To evaluate the efficacy and safety of leukocytapheresis (LCAP) in patients with rheumatoid arthritis (RA) that is refractory to disease modifying antirheumatic drugs (DMARDs), we conducted a prospective, multicenter, open-label clinical trial.

METHODS

We enrolled 38 active RA patients, including 32 patients who showed an inadequate response to > or = 2 DMARDs and 6 patients with rapidly progressive RA. All patients continued drug therapy and were treated with 5 LCAP sessions conducted at 1-week intervals. The clinical response was evaluated at baseline before starting LCAP and at 4 weeks after the completion of all the LCAP sessions using the American College of Rheumatology (ACR) criteria and the 28-joint disease activity score (DAS28) of the European League Against Rheumatism (EULAR).

RESULTS

Of the 35 patients who fulfilled the study's eligibility criteria, 24 (69%), 10 (29%), and 23 (66%) patients achieved 20% (ACR20), 50% (ACR50), and DAS28-C-reactive protein (CRP) EULAR improvement, respectively. The mean DAS28-CRP score of the 35 patients decreased significantly from 5.99 +/- 0.92 at baseline to 4.54 +/- 1.39 after treatment. Comparison analysis of the ACR20 responders and non-responders to LCAP revealed that 22 of 24 responders (92%) concomitantly received methotrexate, whereas significantly fewer, that is, 6 of 11 non-responders (55%) received methotrexate. Less frequent and transient mild-to-moderate adverse events, including nausea and headache, were seen in 12 of 189 LCAP sessions (6.3%).

CONCLUSION

These results demonstrate the usefulness of LCAP in combination with DMARDs, particularly methotrexate, as an effective and safe treatment for refractory RA.

The metabolic syndrome and retinal microvascular signs in a Japanese population: the Funagata study

AIMS

To determine the relationship of metabolic syndrome and its components with retinopathy and other retinal microvascular signs in a Japanese population.

METHODS

The Funagata study recruited 1961 (53.3% of eligible) Japanese aged 35 or older. The metabolic syndrome was diagnosed primarily using definitions of the International Diabetes Federation. Retinopathy and retinal microvascular signs were assessed from fundus photographs. Retinal arteriolar and venular diameters were measured using a computer-assisted programme.

RESULTS

Data were available for analysis in 1638 persons for retinopathy and retinal microvascular signs and 921 persons for retinal vessel diameters. Various components of the metabolic syndrome were associated with retinal microvascular signs: a larger waist circumference was associated with wider venular diameter and retinopathy lesions; a higher blood pressure level was associated with focal arteriolar narrowing, arteriovenous nicking, enhanced arteriolar wall reflex and narrower arteriolar diameter; and a higher triglyceride level was associated with enhanced arteriolar wall reflex. Overall, persons with the metabolic syndrome were more likely to have retinopathy (odds ratio 1.64, 95% CI: 1.02 to 2.64) and wider venular diameter 4.69 microm (95% CI: 1.20 to 8.19 microm) than persons without the metabolic syndrome.

CONCLUSION

We report associations of metabolic syndrome components with retinopathy and wider venular diameter in Japanese adults. These data suggest that metabolic abnormalities, indicated by metabolic syndrome components, are associated with microvascular changes in the retina. There was no synergistic effect of the metabolic syndrome on retinal microvascular changes beyond its individual components.

Antitumor effects of the MIG and IP-10 genes transferred with poly [D,L-2,4-diaminobutyric acid] on murine neuroblastoma

The number of tumor-infiltrating lymphocytes is known to be related to outcomes in patients with a variety of malignancies. Interferon (IFN) gamma-inducible protein-10 (IP-10) and monokine induced by IFNgamma (MIG) have chemotactic effects on activated T lymphocytes and natural killer (NK) cells. The aim of this study was to evaluate the antitumor effects of exogenous expression of the MIG and IP-10 genes delivered to solid tumors by poly [D,L-2,4-diaminobutyric acid] (PDBA). The murine MIG and IP-10 genes were transfected into mouse neuroblastoma cells with PDBA. MIG and IP-10 levels in supernatants of transfected cells were measured by enzyme-linked immunosorbent assay. The chemotactic activities of MIG and IP-10 in the supernatants of cell cultures were measured by chemotaxis assay. Tumors were injected in vivo with PDBA/pmMIGColon, two colonsIP-10 complexes to evaluate the effects of these genes on tumor volume and survival time of mice. Transfected PDBA/pmMIGColon, two colonsIP-10 complexes produced MIG and IP-10 protein in vitro. MIG and IP-10 proteins secreted into the culture medium showed chemotactic activity. MIG and IP-10 gene therapy with the PDBA system in vivo significantly inhibited tumor growth and prolonged survival time of mice. In conclusion, PDBA-mediated MIG and IP-10 gene therapy may be useful for treatment of solid tumors.

Methyl p-hydroxybenzoate causes pain sensation through activation of TRPA1 channels

BACKGROUND AND PURPOSE

Parabens are commonly added in pharmaceutical, cosmetic and food products because of their wide antibacterial properties, low toxicity, inertness and chemical stability, although the molecular mechanism of their antibacterial effect is not fully understood. Some agonists of the transient receptor potential (TRP) A1 channels are known to have strong antibacterial activities. Therefore, a series of experiments was conducted to find out the effects of parabens on TRP channels expressed in sensory neurons, particularly the TRPA1 channels.

EXPERIMENTAL APPROACH

Effects of parabens, especially of methyl p-hydroxybenzoate (methyl paraben) on TRP channel activities were examined using Ca(2+)-imaging and patch-clamp methods. In addition, an involvement of methyl paraben in the development of pain-related behavior in mice was investigated.

KEY RESULTS

Methyl paraben specifically activated TRPA1 in both HEK293 cells expressing TRPA1 and in mouse sensory neurons with an EC(50) value of 4.4 mM, an attainable concentration in methyl paraben-containing products. Methyl paraben caused pain-related behavior in mice similar to that caused by allyl isothiocyanate, which was blocked by the TRP channel blocker, ruthenium red.

CONCLUSIONS AND IMPLICATIONS

Our data indicate that methyl paraben is able to activate TRPA1 channels and can cause pain sensation. As such, methyl paraben provides a useful tool for investigating TRPA1 function and development of antinociceptive agents acting on TRPA1 channels.

Nociception and TRP channels

Pain is initiated when noxious stimuli excite the peripheral terminals of specialized primary afferent neurons called nociceptors. Many molecules are involved in conversion of the noxious stimuli to the electrical signals in the nociceptor endings. Among them, TRP channels play important roles in detecting noxious stimuli.

[Quality control (QC) of CT on rail system (FOCAL Unit) with a micro-multi leaf collimator (mMLC) using new GafChromic film for stereotactic radiotherapy]

PURPOSE

Recent years, CT on rail system was reported to be useful as a tool for image-guided radiotherapy (IGRT). This system was clinically developed with the aim of stereotactic irradiation (STI) for brain, lung, liver, prostate and other sites. Quality assurance and quality control (QC) is an important issue in CT on rail system to assure geometric accuracies. The purpose of this study is to estimate the geometric accuracies of our CT on rail system using a detachable micro-multi leaf collimator (mMLC) with new type radiochromic films. Carrying out our original QC program, translational errors, setup reproducibility, beam misalignment and beam characteristics were evaluated.

METHODS AND MATERIALS

We have studied with CT on rail system (FOCAL unit, Toshiba Medical systems, Tokyo, Japan) and mMLC unit (Accuknife, Direx Inc., Tokyo, Japan). We have developed original alignment phantom and small steel markers (2 mm phi) were implanted on its surface at certain intervals. Firstly, we have evaluated the accuracy of self-moving CT gantry and CT resolutions for cranio-caudal directions by changing slice thickness. And then using the phantom, we have measured the accuracy and reproducibility of geometric isocenter of the linac side and the CT gantry side by scanning the phantom. We have also measured the geometric changes of the common treatment couch by weight-loaded test (up to 135 kgw). To estimate dosimetric and geometric accuracies with the mMLC unit, the misalignment of the beam axes (gantry, collimator and couch rotation axis), mMLC leaf positions, and dose distributions for the verification plan were measured with new type GafChromic films (GafChromic-RTQA, ISP Inc., USA) and cylindrical phantom. The dose characteristics of the GafChromic film were also evaluated.

RESULTS

The reproducibility of the self-moving CT gantry have a good agreement within 1 mm. Weight-load test have shown a good reliability within 2 mm at the common treatment couch. The translational precision of the common treatment couch was 0.0 +/- 0.1 mm at linac side and -0.2 +/- 0.5 mm at CT gantry side. The misalignments of beam axes have been kept within 0.4 mm at maximum. Gap test have shown the accuracies of the mMLC leaf positions, which is needed to keep within 1 mm by a routine calibration.

CONCLUSIONS

To practice quality control program for the FOCAL unit and the mMLC unit is essential for a regular interval to reduce systematic errors. New type radiochromic film would be useful for a verification tool as alternative to conventional film.

Detection of transforming growth factor-alpha and epidermal growth factor receptor mRNA and immunohistochemical localization of the corresponding proteins in the canine uterus during the estrous cycle

Uterine expression of the epidermal growth factor (EGF) family of growth factors has not been studied in the dog. The present study looks at the presence of mRNA transcripts and immunohistochemical localization for transforming growth factor-alpha (TGF-alpha), which is the potent EGF family member, and for EGF receptor (EGF-R) in the canine uterus during the estrous cycle. The reverse transcriptase-polymerase chain reaction together with sequencing of the products confirmed the presence of their mRNA transcripts in the endometrium throughout the estrous cycle. Immunohistochemical analysis found clear positive staining for TGF-alpha and EGF-R in the luminal and glandular epithelia at proestrus and estrus. Immunoreactivity decreased at the early stage of diestrus. In the mid stage of diestrus, clear staining for TGF-alpha was again found in the glands of the luminal region, and staining for EGF-R was observed in all glands. Very little staining was seen at anestrus for either TGF-alpha or EGF-R. These results suggest that TGF-alpha expressed in the uterus may be involved in regulating growth, differentiation and regression in the endometrial epithelial cells during the estrous cycle in the dog.

Temperament and job stress in Japanese company employees

BACKGROUND

This study aims to demonstrate the relevance of temperament to job stress.

METHOD

The subjects were 848 male and 366 female Japanese company employees. Temperament Evaluation of Memphis, Pisa, Paris and San Diego-Autoquestionnaire version (TEMPS-A) and Munich Personality Test (MPT) were administered to assess temperaments, and the NIOSH Generic Job Stress Questionnaire (GJSQ) to assess job stress. We used hierarchical multiple linear regression analysis in order to demonstrate whether temperament variables added any unique variance after controlling the effects of other predictors such as gender, age and job rank.

RESULTS

In all subscales of the GJSQ, temperament predicted a large share of the variance in job stress. Remarkably, for interpersonal relationship stressors, the temperament variables added greater variance than that predicted by gender, age and job rank. Summary of the hierarchical linear regression analysis showed that the irritable temperament was associated with the most prominent vulnerability, followed by cyclothymic and anxious temperaments. The schizoid temperament had difficulty in the area of social support. On the other hand, the hyperthymic temperament displayed significant robustness in facing most job stressors; the melancholic type showed a similar pattern to a lesser degree.

LIMITATION

The findings may be different in a clinical Japanese sample, or a cohort of healthy employees from a different cultural background.

CONCLUSIONS

Temperament influences job stress significantly-indeed, it impacts on such stress with greater magnitude than age, gender and job rank in most areas examined. Temperament influences interpersonal relationship stressors more than workload-related stressors. Interestingly, in line with previous clinical and theoretical formulations, the hyperthymic and melancholic types actually appear to be "hyper-adapted" to the workplace.

Sensitivity of chronically HIV-1 infected HeLa cells to electrical stimulation

Use of combination anti-retroviral drug regimens including protease inhibitors dramatically decreased morbidity and mortality rates in HIV-1 infected individuals. However, such combination therapies appear to have many side effects, in addition to the emergence of resistant HIV-1 strains. Therefore, in this study we sought to elucidate novel therapeutic principles against HIV-1 infection. We examined the effects of electrical stimulation on both chronically HIV-1(LAI) infected HeLa cells (P6 HeLa/HIV-1(LAI)) and uninfected cells (P6 HeLa). Cells were cultured on an optically transparent electrode and application of potential at 1.0 V vs Ag/AgCl was performed over time periods ranging from 10 min to 60 min. Both P6 HeLa/HIV-1(LAI) and P6 HeLa cells were progressively damaged as the duration of electrical stimulation increased. However, P6 HeLa/HIV-1(LAl) cells were much more influenced by electrical stimulation than P6 HeLa cells. The difference in damage rate was most obvious at 30 min of electrical stimulation, with damaged cells accounting for about 87% and 4% of P6 HeLa/HIV-1(LAI) and P6 HeLa cells, respectively. After the application of potential for 20 min, the proliferation of P6 HeLa/HIV-1(LAI) cells was markedly inhibited, while the P6 HeLa cells proliferated to an extent similar to that of uninfected cells without application of potential. These results indicate that sensitivity to electrical stimulation is much higher in chronically HIV-1 infected cells than in uninfected cells. This could be considered as a useful new approach against HIV-1 infection.

Randomized clinical trial of preoperative intranasal mupirocin to reduce surgical-site infection after digestive surgery

BACKGROUND

Compromised patients subjected to major digestive surgery frequently develop infective complications caused by methicillin-resistant Staphylococcus aureus (MRSA), which may have dangerous consequences. This was a prospective randomized study to determine whether intranasal mupirocin could reduce postoperative infective complications in patients having digestive surgery.

METHODS

A total of 395 patients who underwent abdominal digestive surgery were assigned randomly into two groups: a treated group (193 patients) and controls (202). Patients in the treated group were given 30 mg mupirocin calcium hydrate ointment topically to each nostril three times a day on each of the 3 days before operation. The untreated group received no mupirocin treatment.

RESULTS

Most infections were due to Gram-negative bacteria in both groups. There were 21 Gram-positive infections detected at the surgical site, ten in the treated group and 11 in control patients. The incidence of pneumonia was significantly different between the groups (none in the treated group and five in control patients; P = 0.028). Four of five patients with pneumonia had a sputum culture containing MRSA.

CONCLUSION

Intranasal mupirocin treatment had no significant impact on surgical-site infection after digestive surgery.

Effect of electrical stimulation on HIV-1-infected HeLa cells cultured on an electrode surface

Acquired immunodeficiency syndrome (AIDS) is a disease caused by infection with the human immunodeficiency virus (HIV). Although drug therapy for AIDS is available, problems such as side effects associated with drug therapy and the appearance of resistant HIV strains have arisen. Therefore, therapies based on new principles other than drug treatment are required. In the present study, the effect of electrical stimulation on HIV-1(LAI) chronically infected HeLa (P6 HeLa/HIV-1(LAI)) cells cultured on an electrode surface was examined. The results indicated that sensitivity to electrical stimulation was much higher in P6 HeLa/HIV-1(LAI) cells than in uninfected P6 HeLa cells. When electrical stimulation was applied at 1.0 V (vs. Ag/AgCl) for 20 min, the proportion of damage to cell membrane among P6 HeLa/HIV-1(LAI) cells, as evaluated by Trypan blue staining, was approximately 4 times higher than that for uninfected P6 HeLa cells. Furthermore, in comparison with uninfected P6 HeLa cells, the proliferation of P6 HeLa/HIV-1(LAI) cells was significantly suppressed after electrical stimulation. This technique was proven to selectively kill P6 HeLa/HIV-1(LAI) cells, when compared with uninfected control cells.

TRPV1 activation and induction of nociceptive response by a non-pungent capsaicin-like compound, capsiate

Capsiate is a capsaicin-like ingredient of a non-pungent cultivar of red pepper, CH-19 sweet. To elucidate the mechanisms underlying the non-pungency of capsiate, we investigated whether capsiate activates the cloned capsaicin receptor, TRPV1 (VR1). In patch-clamp experiments, capsiate was found to activate TRPV1 expressed transiently in HEK293 cells with a similar potency as capsaicin. Capsiate induced nociceptive responses in mice when injected subcutaneously into their hindpaws with a similar dose dependency as capsaicin. These data indicate that the non-pungent capsiate is an agonist for TRPV1 and could excite peripheral nociceptors. In contrast to this, capsiate did not induce any significant responses when applied to the skin surface, eye or oral cavity of mice, suggesting that capsiate requires direct access to nerve endings to exhibit its effects. Capsiate was proved to have high lipophilicity and to be easily broken down in normal aqueous conditions, leading to less accessibility to nociceptors. Another highly lipophilic capsaicin analogue, olvanil, was similar to capsiate in that it did not produce irritant responses when applied to the skin surface, although it could activate TRPV1. Taken together, high lipophilicity and instability might be critical determinants for pungency and so help in understanding the effects of capsaicin-related compounds.