Attenuation of angiotensin type 2 receptor function in the rostral ventrolateral medullary pressor area of the spontaneously hypertensive rat.

We hypothesized that blockade of angiotensin II type 2 receptors (AT2Rs) in the rostral ventrolateral medullary pressor area (RVLM) may elicit sympathoexcitatory responses which are smaller in hypertensive rats compared to normotensive rats. This hypothesis was tested in urethane-anesthetized, artificially ventilated male 14-week-old spontaneously hypertensive rats (SHR). Age-matched male Wistar-Kyoto rats (WKY) and Wistar rats were used as controls. PD123319 (AT2R antagonist) was microinjected into the RVLM and mean arterial pressure (MAP), heart rate (HR) and greater splanchnic nerve activity (GSNA) were recorded. Increases in MAP, HR and GSNA elicited by unilateral microinjections of PD123319 into the RVLM were significantly smaller in SHR when compared with those in WKY and Wistar rats. Unilateral microinjections of l-glutamate (l-Glu) into the RVLM elicited greater increases in MAP and GSNA in SHR compared to those in WKY. AT2R immunoreactivity was demonstrated in the RVLM neurons which were retrogradely labeled from the intermediolateral cell column (IML) of the spinal cord. These results indicate that AT2Rs are present on the RVLM neurons projecting to the IML and their blockade results in sympathoexcitatory responses. Activation of AT2Rs has an inhibitory influence in the RVLM and these receptors are tonically active. Attenuation of the function of AT2Rs in the RVLM may play a role in genesis and/or maintenance of hypertension in SHR.

Cilnidipine but not amlodipine suppresses sympathetic activation elicited by isometric exercise in hypertensive patients.

Pupillometry was used to evaluate the effects of the calcium channel blockers cilnidipine (CL) and amlodipine (AM) on changes in autonomic nervous activity induced by isometric exercise in patients with hypertension. After handgrip exercise, the velocity of miosis increased in both the CL and AM groups. However, the velocity of mydriasis increased in only the AM group. Velocity slopes of miosis and mydriasis were smaller in the CL group than in the AM group. The low-to-high frequency ratio obtained from pulse wave analysis increased in only the AM group. Sympathetic activation elicited by isometric exercise was suppressed more effectively by CL than by AM.

Cardiovascular responses to microinjections of endomorphin-2 into the nucleus of the solitary tract are attenuated in the spontaneously hypertensive rat.

Stimulation of µ1-opioid receptors (M1ORs) in the medial nucleus solitarius (mNTS) by endomorphin-2 (EM2) elicits decreases in mean arterial pressure (MAP), heart rate (HR) and greater splanchnic nerve activity (GSNA) in Wistar rats. We tested the hypothesis that EM2-induced responses in the mNTS may be attenuated in the spontaneously hypertensive rat (SHR). Experiments were carried out in urethane-anesthetized, artificially ventilated, adult male SHR and Wistar-Kyoto rats (WKY). Alterations in responses to chemical stimulation of the hypothalamic arcuate nucleus (ARCN) after bilateral blockade of M1ORs in the mNTS were also studied. In SHR, microinjections of EM2 into the mNTS elicited smaller decreases in MAP, HR and GSNA compared to those elicited in WKY; smaller cardiovascular responses in SHR can be explained by lower expression of M1OR mRNA in the NTS of SHR compared to WKY. Decreases in MAP and GSNA and increases in HR were elicited by microinjections of N-methyl-D-aspartic acid (NMDA) into the ARCN of WKY. Bilateral blockade of M1ORs in the mNTS attenuated the decreases in MAP and GSNA and exaggerated the increases in HR elicited by the ARCN stimulation in WKY but not in SHR. Tonic inhibitory activity of neuropeptide Y/gamma-aminobutyric acid (NPY/GABA) neurons in the ARCN is attenuated in SHR; this observation may explain increases in MAP, GSNA and HR elicited by microinjections of NMDA into the ARCN of SHR. These results demonstrate that attenuation of EM2-induced responses in the mNTS of SHR may contribute to the excitatory responses elicited by ARCN stimulation in SHR.

Cardiovascular effect of angiotensin-(1-12) in the caudal ventrolateral medullary depressor area of the rat.

Angiotensin (ANG)-(1-12) excites neurons via ANG II type 1 receptors (AT1Rs), which are present in the caudal ventrolateral medullary depressor area (CVLM). We hypothesized that microinjections of ANG-(1-12) into the CVLM may elicit decreases in mean arterial pressure (MAP), heart rate (HR), and sympathetic nerve activity. This hypothesis was tested in urethane-anesthetized adult male Wistar rats. Microinjections of ANG-(1-12) into the CVLM elicited decreases in MAP, HR, and greater splanchnic nerve activity (GSNA). ANG-(1-12)-induced responses consisted of initial (first 1-8 min) and delayed (8-24 min) phases. Prior microinjections of losartan, A-779, and captopril into the CVLM blocked initial, delayed, and both phases of ANG-(1-12) responses, respectively. Blockade of GABA receptors in the rostral ventrolateral medullary pressor area (RVLM) attenuated cardiovascular responses elicited by microinjections of ANG-(1-12) into the ipsilateral CVLM. Microinjections of ANG-(1-12) into the CVLM potentiated the reflex decreases and attenuated the reflex increases in GSNA elicited by intravenous injections of phenylephrine and sodium nitroprusside, respectively. These results indicate that microinjections of ANG-(1-12) into the CVLM elicit decreases in MAP, HR, and GSNA. Initial and delayed phases of these responses are mediated via ANG II and ANG-(1-7), respectively; the effects of ANG II and ANG-(1-7) are mediated via AT1Rs and Mas receptors, respectively. Captopril blocked both phases of ANG-(1-12) responses, indicating that angiotensin-converting enzyme is important in mediating these responses. GABA receptors in the RVLM partly mediate the cardiovascular responses to microinjections of ANG-(1-12) into the CVLM. Microinjections of ANG-(1-12) into the CVLM modulate baroreflex responses.

Cardiac and vascular gene profiles in an animal model of takotsubo cardiomyopathy.

We investigated cardiac and vascular gene profiles in response to immobilization stress (IMO) in rats, an animal model of emotional stress-induced takotsubo cardiomyopathy using microarray analysis, followed by re-confirmation with real-time reverse transcription-polymerase chain reaction. Expression levels of the identified genes were further estimated by pretreatment with an α1-adrenoceptor blocker and/or a ß1-adrenoceptor blocker. In response to IMO, expression of 46 genes was significantly altered in the heart and that of 49 genes was significantly altered in the aorta. Pathway analysis with DAVID Bioinformatics Resources indicated that regulation of transcription and response to endogenous stimulation were the top two scoring pathways. Altered expression of cardiac genes was blunted by pretreatment with a ß1-adrenoceptor blocker or α1 + ß1-adrenoceptor blockers. In contrast, that of aortic genes was blunted by pretreatment with an α1-adrenoceptor blocker or α1 + ß1-adrenoceptor blockers. Activation of α1-adrenoceptor in the blood vessels or activation of ß1-adrenoceptors in the heart were mainly responsible for emotional stress-induced alteration of cardiac and vascular gene profiles.

Radiotherapy for Japanese elderly patients with cervical cancer: preliminary survival outcomes and evaluation of treatment-related toxicity.

PURPOSE: To examine the preliminary survival outcomes and treatment-related toxicity for elderly patients with cervical cancer treated with radiotherapy (RT). METHODS: Forty patients ≥75 years old with cervical cancer who were treated with RT were evaluated. Of these 40 patients, 25 were classified as FIGO stage I or II and 15 as stage III or IVA. Thirty-five patients were treated with radical RT (RRT), and five were treated with surgery plus adjuvant RT (S + ART). External beam radiotherapy combined with high-dose-rate intracavitary brachytherapy was performed on 31 patients who were treated with RRT and on 2 patients who were treated with S + ART because of positive vaginal surgical margins. The patients' median age was 78 years (range 75-89 years). Concurrent chemotherapy (CCT) was performed on five patients (RRT: 3, S + ART: 2). RESULTS: The median follow-up period was 20 months (range 1-85 months). Only one patient could not complete RT. The 3-year overall and disease-specific survival (OS and DSS) rates for all patients were 58 and 80%, respectively. Five patients experienced Grade 3 acute toxicity; two were treated with RRT (2/35), and three were treated with S + ART (3/5, 2 of them with CCT). Two patients experienced Grade 3 late toxicity; one was treated with RRT (1/35, with CCT) and the other was treated with S + ART (1/5). No Grade 4 or higher toxicity was experienced. CONCLUSIONS: RRT for elderly patients with cervical cancer is generally effective and safe, but severe toxicity may occur with more aggressive treatment modalities.

Comparative study of the usefulness of a novel insulin therapy in Japanese patients with Type 2 diabetes for concomitant use of an oral antidiabetic agent with twice-daily dosing either of insulin aspart, biphasic insulin aspart-30, or insulin detemir: Two times Insulin injection Combined with oral therapy Efficacy Study (TWICE study).

OBJECTIVES: It is common to treat type 2 diabetes by regular injections of insulin. We compared the efficacy and safety of twice-daily administration of short-acting, premixed, and long-acting insulins. METHODS: This was a multi-center, randomized, open-label, 52-week study. Patients were randomized to administer twice daily short-acting analog insulin (Aspart) plus a sulfonylurea (SU), premixed 70/30 analog insulin (Mix), or long-acting insulin (Detemir) plus a glinide derivative. RESULTS: Twelve (mean baseline HbA1c 9.86±1.71%), eight (9.24±1.14%), and eight (11.26±1.81%) patients were treated with Aspart, Mix, or Detemir, respectively, for 52 weeks. After 12 weeks, the reductions in HbA1c were similar in the groups. A further significant reduction in HbA1c occurred between weeks 12 and 52 in the Detemir, but not the Aspart or Mix groups. After 52 weeks, the target of an HbA1c <7.4% was achieved in 16.7% of the Aspart group, 37.5% of the Mix group, and 12.5% of the Detemir group (no significant differences among the three groups by χ2 analysis). The mean changes from baseline in blood glucose concentration measured after breakfast, and before and after dinner, were also similar in each group. CONCLUSIONS: Early and meaningful reductions in HbA1c were achieved by twice-daily administration of a premix, aspart plus an SU, and detemir plus a glinide, without severe hypoglycemia or an increase in body mass. However, the target HbA1c was achieved in relatively few participants, perhaps due to an insufficient dose of insulin or the small study size.

Human change and adaptation in Antarctica: Psychological research on Antarctic wintering-over at Syowa station.

An Antarctic wintering-over station is a unique environment, as a small isolated society facing extreme survival margins. Psychological surveys have been done over ten years, including the Baum test, the Positive and Negative Affect Schedule (PANAS), the Coping Orientation to Problems Experienced (COPE), Subjective Health Complaints Inventory (SHC), the Two-Sided Personality Scale (TSPS) and medical consultations in Syowa Station, a Japanese Antarctic station to reveal the mental status of team members. Team members experienced fewer physical health risks in Antarctica than in Japan. Wintering-over team members reinterpreted situations positively and accepted their environment, sought instrumental social support, planned ahead, and used active coping skills and humour to overcome difficulties. They did not act out emotionally or deny problems. Individuals exhibited two types of coping, either stability through maintaining a previous lifestyle or flexible adjustment to a new way of life. Positive affect remained constant during the wintering-over period. In living through a harsh reality, team members drew support from the subjective feelings of an "internal relationship" with home or family in their minds. Thus, an Antarctic wintering-over station is an ideal isolated environment for psychological surveys, which can help understand future space travel and group managements in everyday societies.

Effect of coronary artery bypass grafting on blood pressure response to head-up tilting.

Blood pressure response to head-up tilt (HUT) in 7 healthy subjects and 9 patients before and after coronary artery bypass grafting (CABG) was measured during supine and 15-min 60° HUT. Stroke volume (SV) and ejection fraction (EF) were assessed by echocardiography. Baseline mean arterial pressure (MAP) and heart rate (HR) in patients before CABG were similar to healthy subjects. MAP in patients decreased by 6 (4-9) mmHg [median (1st-3rd quartiles)] during 7-12 mmHg of HUT with decreased cardiac output (CO = SV × HR) while HR remained unchanged. MAP in healthy subjects remained unchanged during HUT with increased HR. Body weight decreased by 3.5 (2.5-3.7) kg and MAP decreased by 6 (2-13) mmHg during the last 3-min HUT while HR increased after CABG. Decreases in SV and CO during HUT disappeared after CABG. Blood pressure decreased during HUT in patients before and after CABG regardless of HR response.

Cardiovascular effects of adrenocorticotropin microinjections into the rostral ventrolateral medullary pressor area of the rat.

The presence of adrenocorticotropic hormone (ACTH)-immunoreactive cells and melanocortin (MC) receptors (MC4 and to a lesser extent MC3) has been demonstrated in the medullary reticular formation in the general area where rostral ventrolateral medullary pressor area (RVLM) is located. The importance of RVLM in the regulation of cardiovascular function is well established. Based on these reports, it was hypothesized that ACTH may play a role in the regulation of cardiovascular function. To test this hypothesis, experiments were carried out on artificially ventilated, adult male, urethane-anesthetized and unanesthetized mid-collicular decerebrate rats. The RVLM was identified by microinjections (100 nl) of L-glutamate (L-Glu). Microinjections (100 nl) of ACTH (0.5, 1 and 2 mmol/l) into the RVLM elicited increases in MAP and HR; tachycardic responses were relatively inconsistent. The effects of ACTH were blocked by SHU9119 and agouti-related protein (AGRP). SHU9119 (a synthetic compound) and AGRP (an endogenous peptide) are antagonists for MC4, and to a lesser extent MC3, receptors. The specificity of these antagonists for MC receptors was indicated by their lack of effect on l-Glu responses. Microinjection of ACTH into the RVLM increased the efferent discharge in the greater splanchnic nerve. It was concluded that (1) ACTH exerts excitatory effects on RVLM neurons resulting in pressor and tachycardic responses, (2) these responses were mediated via MC4 and to a lesser extent MC3 receptors in the RVLM, and (3) the pressor effects of ACTH were mediated via sympathetic activation. This is the first report showing central cardiovascular actions of ACTH.

Development of a detection tablet for a portable NO2 monitoring system.

We have already developed a HCHO monitoring system which is called FP-30. In this experiment, we have developed a NO(2) detection tablet which can be used by the monitoring system. The detection tablet for the NO(2) was constructed with the sensing paper: porous cellulose paper that contains silica gel as an adsorbent, N-1-naphthylethylenediamine dihydrochloride (NED), and glycerin. The NO(2) in sample gas was blown over and adsorbed on the surface of the sensing paper. Then the NO(2) reacted with NED, producing a yellow compound. The coloring reaction took place on the surface of the sensing paper. The degree of color change of paper from white to yellow was monitored as a function of the intensity of the reflected light (lambda = 475 nm) of an LED. The detection limit was 0.01 ppm when the sampling time was 30 min, and the flow rate of sample gas was 250 ml/min. This sensing paper process was not interfered with by acetaldehyde, acetone, alcohols, hydrocarbons, carbon monoxide or carbon dioxide. The NO(2) concentrations in the rooms of a house or school were monitored using this monitoring system and the standard chemiluminescence method. The concentrations of NO(2) monitored by both methods were within 18% of the average. This highly sensitive, selective, and handy NO(2) gas monitoring system will be widely applicable and convenient for users who are not specialists in this field.

Effects of azelnidipine and amlodipine on exercise-induced sympathoexcitation assessed by pupillometry in hypertensive patients.

The pupil is a suitable end organ for studying autonomic function because both sympathetic and parasympathetic nerve activity can be evaluated independently using a light stimulus. Sympathetic response elicited by physical stress is augmented in hypertensive patients compared with normotensive subjects, which increases the risk of cardiovascular events. We used pupillometry to evaluate the effects of the calcium channel blockers azelnidipine (AZ) and amlodipine (AM) on changes in autonomic nervous activity induced by isometric exercise in patients with hypertension. Twenty patients with essential hypertension who were administered AM and 21 who were administered AZ underwent a pupillary function test and blood pressure (BP) and pulse rate (PR) measurements before and after isometric handgrip exercise (IHG). Maximal velocities of pupil constriction (VC) and re-dilation (VD) obtained with light stimulation for 1 s were used as indices of parasympathetic and sympathetic nerve activity, respectively. Increases in systolic BP and PR elicited by IHG were significantly smaller in the AZ group than in the AM group. After IHG, both VC and VD significantly increased in the AM group but not in the AZ group. The low-to-high frequency ratio obtained from analysis of PR variability, another measure of sympathetic activity, also increased in only the AM group. Thus AZ inhibited autonomic activation and suppressed cardiovascular responses to IHG more effectively than AM. The sympathoinhibitory effect of AZ may therefore be beneficial for patients with essential hypertension. In addition, pupillometry was shown to be a useful tool for assessing autonomic function in hypertensive patients.

Surgical Management of Unilateral Soft Tissue Swelling around the Proximal Interphalangeal Joint in an Adolescent: A Case Report of Pachydermodactyly.

Pachydermodactyly (PDD) is a rare and benign acquired form of digital fibromatosis, characterized by asymptomatic fusiform soft tissue hypertrophy of the lateral aspect of the proximal interphalangeal (PIP) joints of the fingers. The etiology of PDD remains unknown, but it usually affects healthy males around the age of puberty. It can be misdiagnosed as inflammatory rheumatic diseases, especially as juvenile chronic arthritis. Here, we report a case of PDD in an 18-year-old man who had progressive fusiform swelling of the PIP joint on his left middle finger. Although he had no pain or functional limitation of movement, he chose to undergo surgical resection of the lesion to obtain a conclusive diagnosis and to rectify the deformity's appearance. Histologically, the lesion was characterized by coarse fibrosis in the adipose tissue, peripheral nerve fibers, and eccrine glands; this is compatible with a diagnosis of PDD.

Angiosarcoma treated with radiotherapy: impact of tumor type and size on outcome.

PURPOSE: Angiosarcoma is a rare and highly malignant vascular neoplasm. The purpose of this study was to elucidate the tumor characteristics and evaluate the efficacy of radiotherapy (RT) for angiosarcoma. MATERIALS AND METHODS: Thirty patients with angiosarcoma (20 males and 10 females, age range 4-89 years, median 66) who received RT from 1986 to 1999 were enrolled in the study. Twenty-four patients had angiosarcoma of the face and scalp (AFS), and 6 patients had angiosarcomas at other sites. AFS was classified into two categories (according to the macroscopic features): nodular AFS (14 patients) and endophytic AFS (10 patients). The median prescribed irradiation dose was 68 Gy. Surgery had been previously performed in 9 patients, and adjuvant immunotherapy using recombinant interleukin-2 (rIL-2) was combined during and after RT in 20 patients. Univariate analyses and calculation of survival by Kaplan-Meier methods were performed. RESULTS: Local tumor control was obtained in 17 patients (57%). However, 7 (47%) of them developed distant metastases. The median survival time for all patients was 8 months (7 months for AFS), and the 13-year overall survival rate was 25% (20% for AFS). Twenty-one patients died of angiosarcoma, with the cause of death local failure in 7 patients, distant failure in 7, and both in 7. Tumor type and size were found to be significant prognostic factors (p = 0.004 and p = 0.007, respectively), and age, total amount of rIL-2, gender, radiation dose, and surgery were not. Six patients (4 with nodular AFS and 2 with angiosarcoma in other parts) survived >2 years. No patient with endophytic AFS survived >2 years. Ten patients (33%) died of respiratory failure secondary to pulmonary metastases. High-dose rIL-2 administration suppressed the occurrence of distant metastases (p = 0.006). Two patients developed radiation dermatitis (Radiation Therapy Oncology Group Grade 4). CONCLUSION: RT, combined with complete resection or adjuvant rIL-2 immunotherapy, could be a promising treatment strategy, leading to prolonged survival in patients with angiosarcoma.

[Assessment of left ventricular function by thallium-201 quantitative gated cardiac SPECT].

PURPOSE: Present study was designed to evaluate the accuracy of the measurement of left ventricular volume by quantitative gated SPECT (QGS) software using 201T1 and the effect of cutoff frequency of Butterworth prereconstruction filter on the calculation of volume. METHODS: The RH-2 type cardiac phantom and 20 patients with ischemic heart disease were studied. Left ventricular end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (EF) were calculated by the QGS software using the various frequency of Butterworth filter. These parameters were evaluated by Simpson's method using left ventriculography (LVG). RESULTS: The volume of the phantom calculated by QGS was under-estimated by 14%. In the clinical study, EDV and ESV measured by QGS were smaller than those obtained from LVG by 10%. When the cutoff frequency of Butterworth filter was 0.43 cycles/cm, the values measured by QGS were best correlated with those by LVG (EDV: r = 0.80, p < 0.001; ESV: r = 0.86, p < 0.001; EF: r = 0.80, p < 0.001). CONCLUSION: These data suggest that 201Tl quantitative gated cardiac SPECT can estimate myocardial ischemia and left ventricular function simultaneously.

Tonic γ-aminobutyric acid-ergic activity in the hypothalamic arcuate nucleus is attenuated in the spontaneously hypertensive rat.

We tested the hypothesis that tonic γ-aminobutyric acid-ergic activity in the hypothalamic arcuate nucleus (ARCN) modulates blood pressure control and attenuation of this inhibitory activity contributes to hypertension in the spontaneously hypertensive rats (SHR). Mean arterial pressure (MAP), heart rate (HR), and greater splanchnic nerve activity (GSNA) were recorded in urethane-anesthetized, artificially ventilated, adult male SHR and Wistar-Kyoto rats (WKY). Microinjections of gabazine into the ARCN elicited significantly smaller increases in MAP, HR, and GSNA in baroreceptor-intact SHR compared with baroreceptor-intact WKY. Attenuation of the responses to gabazine in SHR persisted, despite lowering of their baseline MAP to levels of WKY or barodenervation. Microinjections of N-methyl-d-aspartic acid (NMDA) into the ARCN elicited decreases in MAP and GSNA and increases in HR in baroreceptor-intact WKY. However, after microinjections of gabazine into the ARCN, microinjections of NMDA into the same nucleus elicited pressor responses in baroreceptor-intact WKY. In barodenervated WKY, increases in MAP and GSNA were elicited by ARCN stimulation by NMDA and the increases in HR were exaggerated. In baroreceptor-intact SHR, ARCN stimulation by NMDA elicited increases in MAP, GSNA, and HR which persisted, despite lowering of baseline MAP or barodenervation. Increases in MAP and GSNA elicited by ARCN stimulation by NMDA in barodenervated SHR were significantly greater than corresponding increases in barodenervated WKY. These results indicated that attenuated γ-aminobutyric acid-ergic activity in the ARCN and impaired baroreflex function may contribute to increases in blood pressure and sympathetic nerve activity after ARCN stimulation by NMDA and elevation of baseline blood pressure in SHR.

Effect of barodenervation on cardiovascular responses elicited from the hypothalamic arcuate nucleus of the rat.

We have previously reported that chemical stimulation of the hypothalamic arcuate nucleus (ARCN) in the rat elicited increases as well as decreases in blood pressure (BP) and sympathetic nerve activity (SNA). The type of response elicited from the ARCN (i.e., increase or decrease in BP and SNA) depended on the level of baroreceptor activity which, in turn, was determined by baseline BP in rats with intact baroreceptors. Based on this information, it was hypothesized that baroreceptor unloading may play a role in the type of response elicited from the ARCN. Therefore, the effect of barodenervation on the ARCN-induced cardiovascular and sympathetic responses and the neurotransmitters in the hypothalamic paraventricular nucleus (PVN) mediating the excitatory responses elicited from the ARCN were investigated in urethane-anesthetized adult male Wistar rats. Bilateral barodenervation converted decreases in mean arterial pressure (MAP) and greater splanchnic nerve activity (GSNA) elicited by chemical stimulation of the ARCN with microinjections of N-methyl-D-aspartic acid to increases in MAP and GSNA and exaggerated the increases in heart rate (HR). Combined microinjections of NBQX and D-AP7 (ionotropic glutamate receptor antagonists) into the PVN in barodenervated rats converted increases in MAP and GSNA elicited by the ARCN stimulation to decreases in MAP and GSNA and attenuated increases in HR. Microinjections of SHU9119 (a melanocortin 3/4 receptor antagonist) into the PVN in barodenervated rats attenuated increases in MAP, GSNA and HR elicited by the ARCN stimulation. ARCN neurons projecting to the PVN were immunoreactive for proopiomelanocortin, alpha-melanocyte stimulating hormone (alpha-MSH) and adrenocorticotropic hormone (ACTH). It was concluded that increases in MAP and GSNA and exaggeration of tachycardia elicited by the ARCN stimulation in barodenervated rats may be mediated via release of alpha-MSH and/or ACTH and glutamate from the ARCN neurons projecting to the PVN.

Cardiovascular responses to chemical stimulation of the hypothalamic arcuate nucleus in the rat: role of the hypothalamic paraventricular nucleus.

The mechanism of cardiovascular responses to chemical stimulation of the hypothalamic arcuate nucleus (ARCN) was studied in urethane-anesthetized adult male Wistar rats. At the baseline mean arterial pressure (BLMAP) close to normal, ARCN stimulation elicited decreases in MAP and sympathetic nerve activity (SNA). The decreases in MAP elicited by ARCN stimulation were attenuated by either gamma-aminobutyric acid (GABA), neuropeptide Y (NPY), or beta-endorphin receptor blockade in the ipsilateral hypothalamic paraventricular nucleus (PVN). Combined blockade of GABA-A, NPY1 and opioid receptors in the ipsilateral PVN converted the decreases in MAP and SNA to increases in these variables. Conversion of inhibitory effects on the MAP and SNA to excitatory effects following ARCN stimulation was also observed when the BLMAP was decreased to below normal levels by an infusion of sodium nitroprusside. The pressor and tachycardic responses to ARCN stimulation at below normal BLMAP were attenuated by blockade of melanocortin 3/4 (MC3/4) receptors in the ipsilateral PVN. Unilateral blockade of GABA-A receptors in the ARCN increased the BLMAP and heart rate (HR) revealing tonic inhibition of the excitatory neurons in the ARCN. ARCN stimulation elicited tachycardia regardless of the level of BLMAP. ARCN neurons projecting to the PVN were immunoreactive for glutamic acid decarboxylase 67 (GAD67), NPY, and beta-endorphin. These results indicated that: 1) at normal BLMAP, decreases in MAP and SNA induced by ARCN stimulation were mediated via GABA-A, NPY1 and opioid receptors in the PVN, 2) lowering of BLMAP converted decreases in MAP following ARCN stimulation to increases in MAP, and 3) at below normal BLMAP, increases in MAP and HR induced by ARCN stimulation were mediated via MC3/4 receptors in the PVN. These results provide a base for future studies to explore the role of ARCN in cardiovascular diseases.

Multi-institutional analysis of solitary extramedullary plasmacytoma of the head and neck treated with curative radiotherapy.

PURPOSE: The purpose of this study was to elucidate the efficacy and optimal method of radiotherapy in the management of solitary extramedullary plasmacytoma occurring in the head and neck regions (EMPHN). METHODS AND MATERIALS: Sixty-seven patients (43 male and 24 female) diagnosed with EMPHN between 1983 and 2008 at 23 Japanese institutions were reviewed. The median patient age was 64 years (range, 12-83). The median dose administered was 50 Gy (range, 30-64 Gy). Survival data were calculated by the Kaplan-Meier method. RESULTS: The median follow-up duration was 63 months. Major tumor sites were nasal or paranasal cavities in 36 (54%) patients, oropharynx or nasopharynx in 16 (23%) patients, orbita in 6 (9%) patients, and larynx in 3 (5%) patients. The 5- and 10-year local control rates were 95% and 87%, whereas the 5- and 10-year disease-free survival rates were 56% and 54%, respectively. There were 5 (7.5%), 12 (18%), and 8 (12%) patients who experienced local failure, distant metastasis, and progression to multiple myeloma, respectively. In total, 18 patients died, including 10 (15%) patients who died due to complications from EMPHN. The 5- and 10-year overall survival (OS) rates were 73% and 56%, respectively. Radiotherapy combined with surgery was identified as the lone significant prognostic factor for OS (p = 0.04), whereas age, gender, radiation dose, tumor size, and chemotherapy were not predictive. No patient experienced any severe acute morbidity. CONCLUSIONS: Radiotherapy was quite effective and safe for patients with EMPHN. Radiotherapy combined with surgery produced a better outcome according to survival rates. These findings require confirmation by further studies with larger numbers of patients with EMPHN.

Vitamin K2-derived compounds induce growth inhibition in radioresistant cancer cells.

A strategy to overcome radioresistance in cancer treatment has been expected. To evaluate the strategy, appropriate experimental models are needed. Radioresistant tumour models were originally established from human colon cancer cells, and we evaluated their molecular basis. Next, the growth inhibitory effects of newly synthesized vitamin K2 (VK2)-related compounds were tested. Here, we showed that these novel compounds have growth inhibitory effects not only on cancer cells of various origins, but also on radioresistant cells, through the generation of reactive oxygen species (ROS). Human colon, lung, and breast cancer cell lines were used for testing the growth inhibitory activities of several chemical compounds. Radioresistant tumour models were established by fractionated radiation exposure. Irradiated cells were selected by a single cell cloning method, and their sensitivity to ionizing radiation was evaluated by a colony-forming assay. The VK2 derivatives (named MQ-1, MQ-2, and MQ-3) were chemically synthesized. To evaluate the generation of ROS, flow cytometer analyses were performed. A radioresistant tumour model was established from the HCT116 human colon cancer cell line. The radioresistant cells from HCT116 also showed resistance to cisplatin. In the radioresistant cells, NF-κB was highly activated. MQ-1, MQ-2, and MQ-3 showed greater growth inhibitory activities than VK2 not only in various cancer cells but also in radioresistant cells through the generation of ROS. In conclusion, a radioresistant tumour model was originally established from colon cancer cell lines through NF-κB activation, and it could be a useful tool for evaluating anti-tumour agents. Newly synthesized VK2 derivatives (MQ-1, MQ-2 and MQ-3) seemed to be potential anti-tumour agents in various cancers and radioresistant cancers. The efficacy of those compounds was related to the generation of ROS. These findings together might pave the way for the treatment of radioresistant or recurrent cancers.