Additional chromosomal abnormalities in core-binding factor acute myeloid leukemia.

Despite sharing a similar genetic abnormality, patients with core binding factor acute myeloid leukemia (CBF-AML), which is characterized by the presence of t(8;21) or inv(16)/t(16;16), show heterogeneous survival. Other molecular or cytogenetic factors are supposed to have an impact on the prognosis. We enrolled 24 CBF-AML patients to determine the impact of cytogenetic abnormality, and c-KIT, FLT3, NPM1, and CEBPA mutations on the prognosis. Only three patients had the c-KIT mutation (3/24, 12.5%) and one had the FLT3 mutation. However, over half of the patients (14/24) harbored additional cytogenetic changes, including ten with loss of sexual chromosomes (LOS) [all in the t(8;21) group], and six had additional abnormalities (two cases had both LOS and additional abnormalities). From this small-number study, no association was found between c-KIT mutation and survival and relapse rate. However, additional chromosome abnormalities had a significant association with relapse of the disease (P = 0.027). Stem cell transplant had a trend of benefitting patients after relapse (P = 0.065). This implies that chromosome abnormalities occur in CBF-AML and might take part in the heterogeneous nature of CBF-AML.

Pertuzumab plus trastuzumab in combination with standard neoadjuvant anthracycline-containing and anthracycline-free chemotherapy regimens in patients with HER2-positive early breast cancer: a randomized phase II cardiac safety study (TRYPHAENA).

BACKGROUND: Pertuzumab (P) combined with trastuzumab (H)-based chemotherapy improves efficacy in early and advanced HER2-positive breast cancer. We assessed the tolerability, with particular focus on cardiac safety, of H and P with chemotherapy in the neoadjuvant treatment of HER2-positive early breast cancer. PATIENTS AND METHODS: In this multicenter, open-label phase II study, patients with operable, locally advanced, or inflammatory breast cancer were randomized 1 : 1 : 1 to receive six neoadjuvant cycles q3w (Arm A: 5-fluorouracil, epirubicin, cyclophosphamide [FEC] + H + P ×3 → docetaxel [T] + H + P ×3; Arm B: FEC ×3 → T + H + P ×3; Arm C: T + carboplatin + H [TCH]+P ×6). pCR was assessed at surgery and adjuvant therapy given to complete 1 year of H. RESULTS: Two hundred twenty-five patients were randomized. During neoadjuvant treatment, two patients (2.7%; Arm B) experienced symptomatic left ventricular systolic dysfunction (LVSD) and 11 patients (Arm A: 4 [5.6%]; Arm B: 4 [5.3%]; Arm C: 3 [3.9%]) had declines in left ventricular ejection fraction of ≥10% points from baseline to <50%. Diarrhea was the most common adverse event. pCR (ypT0/is) was reported for 61.6% (Arm A), 57.3% (Arm B), and 66.2% (Arm C) of patients. CONCLUSION: The combination of P with H and standard chemotherapy resulted in low rates of symptomatic LVSD.

Decreased expression of PIAS1 and PIAS3 in essential thrombocythemia patients.

Gain of function mutation of Janus kinase 2 (JAK2V617F) has been identified in Philadelphia-negative myeloproliferative diseases; about half of essential thrombocythemia (ET) patients harbor this mutation. The activated JAK-STAT pathway promotes cell proliferation, differentiation and anti-apoptosis. We studied the role of negative regulators of the JAK-STAT pathway, PIAS, and SOCS in ET patients. Twenty ET patients and 20 healthy individuals were enrolled in the study. Thirteen of the ET patients harbored the JAK2V617F mutation based on mutation analysis. Quantitative-PCR was applied to assay the expression of SOCS1, SOCS3, PIAS1, PIAS3. The expression levels of PIAS1 and PIAS3 were significantly lower in ET groups than that in normal individuals. There was no significant difference between JAK2V617F (+) and JAK2V617F (-) patients. SOCS1 and SOCS3 expression did not differ between ET patients and normal individuals, or between JAK2V617F (+) and JAK2V617F (-) patients. We suggest that failed negative regulators of the JAK-STAT pathway take part in the pathomechanism of ET.

Right- and left-subclavian vein port-a-cath systems: comparison of complications.

BACKGROUND: Central venous access systems are frequently used for delivery of medications; however, few studies have compared surgical and postoperative complications of right versus left access via the subclavian vein (SCV). The aim of this study was to compare the surgical and postoperative complications associated with Port-A-Cath system insertion via the right and left SCV. METHODS: The medical records of patients who received Port-A-Cath insertion via the SCV for parenteral chemotherapy between August 2004 and July 2008 were reviewed. The incidence of surgical and postoperative complications was compared between patients who received right- versus left-SCV Port-A-Cath insertion. RESULTS: A total of 1,848 patients were included in the study. Right-SCV catheterization was attempted in 1,029 (55.7%) patients and was successful in 866 (84.2%). Left-SCV catheterization was attempted in 819 (44.3%) patients and was successful in 651 (79.5%). The mean length of postoperative follow-up was 417.3 ± 401.3 and 396.7 ± 379.9 days for the right- and left-SCV groups, respectively. The incidence of SCV puncture failure was significantly lower in the right-SCV group (12.3%) compared with the left-SCV group (16.8%, p = 0.006). The incidence of catheter knotting at the ipsilateral brachiocephalic vein was also significantly lower in the right-SCV group (0.0%) compared with the left-SCV group (0.5%, p = 0.038), as was the incidence of catheter occlusion (1.0% for right SCV vs. 3.5% for left SCV, p = 0.001). CONCLUSION: These findings suggest that the right-SCV approach is superior to the left-SCV approach for Port-A-Cath insertion.

Impact of breast cancer patients' awareness on attendance at screening.

AIM: The purpose of this study is to investigate the impact of breast cancer awareness on the attendance for screening among women with breast cancer prior to diagnoses of breast cancer. BACKGROUND: Breast cancer is the most commonly diagnosed cancer for women in Taiwan and its incidence rate continues to increase. However, screening for breast cancer is still not common even if the incidence rate has topped the list from 2003 to 2010. METHODS: A cross-sectional study was conducted among women diagnosed with breast cancer. Subjects (535 women) were recruited from two medical centres in central Taiwan. Information on attendance for breast cancer screening was collected by self-report. Chi-square test and logistic regression were utilized to analyse the relationships between awareness of breast cancer and attendance at screening. FINDINGS: The results indicated that pre-diagnostic awareness of 'the concept of early treatment relating to higher cure rate'[odds ratio (OR): 4.09; 95% confidence interval (CI): 1.12-14.9], 'various breast cancer screening methods' (OR:3.00; 95% CI: 1.23-7.30), 'the coverage of breast cancer screening programme in the National Health Insurance' (OR:1.76; 95% CI: 1.03-3.02) and 'breast self-examination after each menstrual cycle' (OR:3.42; 95% CI: 1.99-5.87) were all significantly associated with the screening procedures performed. CONCLUSIONS: Findings of this study indicated that particular attention should be paid towards enhancement of women's knowledge for prevention and early detection of breast cancer through educational efforts by nurse professionals, medical institutions and/or civil organizations.

Surgical treatment of 26 patients with necrotizing pneumonia.

BACKGROUND: This study aimed to review the outcome of patients treated with surgical resection for necrotizing lung infection with various co-morbidities and complications. METHODS: The records of 26 patients treated with pulmonary resection for necrotizing pneumonia between July 2004 and January 2010 were retrospectively reviewed. Surgical procedures included large wedge resection (n = 1), lobectomy (n = 19) and bilobectomy (n = 6). RESULTS: The study cohort consisted of 21 men and 5 women aged 35-85 years (mean 64.7 ± 15.0 years). Twenty-three (88.5%) patients had underlying risk factors. At surgical consultation, 17 patients presented with progressive respiratory distress; 6 required ventilatory support; 12 had empyema, and in 5 patients the conditions were complicated by bronchopleural fistula. Four patients had septic shock requiring vasopressor support. Three patients developed hemoptysis. Two patients had bilateral diffuse pneumonia. Klebsiella pneumoniaeand Streptococcusviridans were the most common pathogens. The right lower (n = 13) and right middle lobes (n = 10) were the most frequently affected. Four deaths (15.4%) occurred: 3 due to perioperative progressing pulmonary infection/inflammation and 1 due to hepatorenal failure. Postoperative empyema occurred in 3 patients. One patient became ventilator dependent. CONCLUSION: Pulmonaryresection for necrotizing pneumonia is a feasible treatment option in patients with progressive pulmonary sepsis.

Prevalence, correlates, and self-management of HIV-related depressive symptoms.

Depressive symptoms are highly prevalent yet undertreated in people living with HIV/AIDS (PLHAs). As part of a larger study of symptom self-management (N=1217), this study examined the prevalence, correlates, and characteristics (intensity, distress, and impact) of depressive symptoms, and the self-care strategies used to manage those symptoms in PLHAs in five countries. The proportion of respondents from each country in the total sample reporting depressive symptoms in the past week varied and included Colombia (44%), Norway (66%), Puerto Rico (57%), Taiwan (35%), and the USA (56%). Fifty-four percent (n=655) of the total sample reported experiencing depressive symptoms in the past week, with a mean of 4.1 (SD 2.1) days of depression. Mean depression intensity 5.4 (SD 2.7), distressfulness 5.5 (SD 2.86), and impact 5.5 (SD 3.0) were rated on a 1-10 scale. The mean Center for Epidemiologic Studies Depression Scale score for those reporting depressive symptoms was 27 (SD 11; range 3-58), and varied significantly by country. Respondents identified 19 self-care behaviors for depressive symptoms, which fell into six categories: complementary therapies, talking to others, distraction techniques, physical activity, medications, and denial/avoidant coping. The most frequently used strategies varied by country. In the US sample, 33% of the variance in depressive symptoms was predicted by the combination of education, HIV symptoms, psychological and social support, and perceived consequences of HIV disease.

HIV illness representation as a predictor of self-care management and health outcomes: a multi-site, cross-cultural study.

Research has shown that the perceptions that form the cognitive representation of an illness (illness representation) are fundamental to how persons cope with illness. This study examined the relationship of illness representation of HIV with self-care behavior and health outcomes. Data were collected at 16 sites in the United States, Taiwan, Norway, Puerto Rico and Colombia via survey. HIV seropositive participants (n = 1,217, 31% female, 38% African-American/Black, 10% Asian/Pacific Islander and 26% White/Anglo) completed measures of illness representation based on the commonly accepted five-component structure: identity, time-line, consequences, cause, and cure/controllability (Weinman et al. 1996, Psychology and Health, 11, 431-445). Linear regression analyses were conducted to investigate relationships among illness representation, self-care behaviors and quality-of-life outcomes. Components of illness representation were associated with self-care and health outcomes, indicating that the cognitive representation of HIV has consequences for effective illness management. For example, perception that there is little that can be done to control HIV was significantly associated with fewer and less effective self-care activities (F = 12.86, P < .001) and poorer health function in the domain of quality-of-life (F = 13.89, P < .001). The concept of illness representation provides a useful framework for understanding HIV symptom management and may be useful in directing development of effective patient-centered interventions.

Sexual motivation is demasculinized, but not feminized, in prenatally stressed male rats.

Sexual motivation and copulation in male rats are associated with dopamine release in the nucleus accumbens. Demasculinized copulatory behavior has been demonstrated in prenatally stressed adult male rats. We have previously reported that approximately 80% of prenatally stressed male rats do not exhibit copulation and that no significant changes in nucleus accumbens dopamine release are seen during exposure to estrous females. In the present study, we investigated whether prenatal stress affects sexual motivation in these animals as adults. Pregnant Wistar rats were subjected to immobilization stress for two hours daily from day 15-19 of gestation. The prenatally stressed male offspring at the age of 3 months were allowed contact with receptive female rats for a 30 min period per week for 10 weeks; then, between the age of 5 and 6 months, their sexual motivation and copulatory activity were measured. Sexual motivation was measured in terms of sexual partner preference. The number of visits and the duration of each visit to an estrous female (stimulus female) or to a sexually active male rat (stimulus male) were recorded. Compared with control males, prenatally stressed male rats showed a significantly lower number of visits and a shorter duration of each visit to stimulus females. Prenatally stressed males showed no preference for male or female stimulus rats in terms of the number of visits and the duration of each visit, whereas control rats showed a significantly higher number of visits and duration of visits to female stimulus rats than male stimulus rats. A significant decrease in copulatory activity was observed in the prenatally stressed male offspring compared with control male rats, with most of the prenatally stressed males failing to show copulation. In vivo microdialysis experiments were performed on the nucleus accumbens with concurrent observation of sexual behavior. The prenatally stressed rats that did not exhibit copulation showed no significant changes in nucleus accumbens dopamine release during exposure to a stimulus male behind a wire-mesh barrier and the amount of dopamine release remained at the basal levels during actual physical contact. These results, combined with those of our previous report, indicate that sexual motivation in prenatally stressed male rats is demasculinized, but not feminized.

Pulse Oximeter-Derived Pleth Variability Index is a Reliable Indicator of Cardiac Preload in Patients Undergoing Liver Transplantation.

BACKGROUND: Accurate estimation of cardiac preload during liver transplantation is essential. The right ventricular end-diastolic volume index (RVEDVI) is recognized as a good preload indicator in patients undergoing liver transplantation. Recently, dynamic variation parameters including pleth variability index (PVI) have been used as predictors of fluid responsiveness. However, the correlation between PVI and preload status has not been well studied. We evaluated the relationship between PVI and RVEDVI during liver transplantation. METHODS: Eighteen patients undergoing liver transplantation were enrolled in this study. Data of hemodynamic parameters including PVI derived by Masimo Rainbow SET Pulse CO-Oximeter, central venous pressure (CVP), pulmonary arterial occlusion pressure (PAOP), and RVEDI were obtained at 10 defined time points throughout liver transplantation. The correlation between RVEDVI and CVP, PAOP, and PVI was analyzed using Spearman rank test. We also investigated the ability of PVI to accurately differentiate RVEDVI <123 or >142 mL/m(2) using receiver operating characteristic (ROC) analysis. RESULTS: There was fair to good correlation between PVI and RVEDVI (correlation coefficient = -0.492, P < .001). The correlation coefficient between CVP, PAOP, and RVEDVI was 0.345 and 0.463, respectively. A 13.5% cutoff value of PVI estimated the RVEDVI <123 mL/m(2) (area under the curve [AUC] = 0.762). A 12.5% cutoff value of PVI estimated the RVEDVI >142 mL/m(2) (AUC = 0.745). CONCLUSIONS: PVI presented as a reliable estimate of preload status and may be a useful predictor of fluid responsiveness in patients undergoing liver transplantation.

Accuracy and Trending of Continuous Noninvasive Hemoglobin Monitoring in Patients Undergoing Liver Transplantation.

BACKGROUND: Shift in large fluid volumes and massive blood loss during liver transplantation frequently leads to rapid changes in hemoglobin (Hb) concentration; thus, to ensure adequate tissue oxygenation, accurate and rapid determination of Hb concentration is essential in transplant recipients. The Radical-7 Pulse CO-Oximeter provides a noninvasive and continuous way to monitor Hb concentration (SpHb) in real time and is an ideal candidate for use during liver transplantation. In this study, we assessed the relationship between SpHb and total Hb (tHb) obtained from arterial blood samples during surgery. METHODS: Forty patients undergoing liver transplantation were enrolled in this study. tHb and time-matched SpHb were measured at 5 different phases throughout surgery. Paired SpHb and tHb levels were assessed using linear regression, Bland-Altman analysis, and the Critchley polar plot method. RESULTS: A total of 161 paired measurements with sufficient signal quality were analyzed. The correlation between SpHb and tHb was 0.59 (P < .001). Bland-Altman analysis revealed that a bias between SpHb and tHb was 2.28 g/dL, and limits of agreement (LoA) were from -0.78 to 5.34 g/dL. Trending analysis showed that 87% of data were located within the acceptable trending area, indicating that the trending ability was not satisfied. CONCLUSIONS: The Radical-7 Pulse CO-Oximeter was not sufficient to monitor Hb levels and trends during liver transplantation surgery in our cohort. In particular, in critical patients and in those with low Hb levels, invasive Hb measurement should be used for assessment.

Cardiac Output Assessed by the Fourth-Generation Arterial Waveform Analysis System Is Unreliable in Liver Transplant Recipients.

BACKGROUND: Liver transplant recipients often have violent hemodynamic fluctuation during surgery that may be related to perioperative and postoperative morbidity. Because there are some considerations for the risk of the pulmonary arterial catheter (PAC), the conventional invasive device for cardiac output (CO) measurement, a reliable and minimally invasive alternative is required. We validated the reliability of CO measurements with the use of a minimally invasive FloTrac system with the latest fourth-generation algorithm in liver transplant recipients. METHODS: Forty liver transplant recipients without atrial fibrillation, valvular pathology, or intracardiac shunt were recruited in this prospective, observational study. CO values measured by use of PAC with continuous thermodilution method (COTh) and FloTrac devices (COFT) were collected simultaneously throughout the operation for reliability validation. RESULTS: Four hundred pairs of CO data points were collected in total. The linear regression analysis showed a high correlation coefficient (73%, P < .001). However, the percent error between COTh and COFT was 42.2%, which is worse than the established interchangeability criterion of 30%. The concordance rates were calculated at 89% and 59% by 4-quadrant plot and polar plot analysis, respectively. Neither met the preset validation criteria (>92% for the 4-quadrant plot and >90% for polar plot analyses). CONCLUSIONS: Our study demonstrates that the CO measurements in liver transplant recipients by the latest FloTrac system and the PAC do not meet the recognized interchangeability criterion. Although the result showed improvement in linear regression analysis, it failed to display a qualified trending ability.

The detection of the HLA-B27 antigen by immunomagnetic separation and enzyme-linked immunosorbent assay-comparison with a flow cytometric procedure.

The HLA-B27 antigen is an important genetic marker in ankylosing spondylitis (AS). Methods for the detection of B27 include the microlymphocytotoxicity test and, more recently, flowcytometry (FC). Here, we describe a new method, IMS-ELISA, for measuring the B27-antigen. It combines immunomagnetic separation (IMS), to obtain B27-positive cells from whole blood samples, with an enzyme-linked immunosorbent assay (ELISA) as a read-out. IMS-ELISA was tested on 367 samples obtained from five different hospitals in Taiwan. The sensitivity, specificity and accuracy of the method were compared with FC. Any conflicting data between IMS-ELISA and FC was confirmed by HLA-DNA typing via PCR-SSP (polymerase chain reaction-sequence specific primers). Overall, the results for sensitivity, specificity and accuracy obtained by IMS-ELISA and FC did not show any significant difference (p>0.05). However, when considering laboratory time, cost, ease of operation and the screening of large samples for HLA-B27, the IMS-ELISA was superior to the FC method. We conclude that IMS-ELISA may be used as a fast screening method for HLA B27 detection.

Effects of food restriction on mechanical properties of arterial system in adult and middle-aged rats.

The effects of food restriction on the mechanical properties of the vasculature were determined in Long-Evans male rats with different ages. Rats that began food restriction at the ages of 6 months and 12 months were fed on alternate days for 6 months. Rats at the ages of 12 and 18 months were referred to as adult and middle-aged rats and were anesthetized and thoracotomized. The exponentially tapered T-tube model was employed to relate pulsatile pressure and flow signals measured in the ascending aorta. In each age group, food restriction elicited a decrease in body weight as well as basal heart rate but showed no significant change in cardiac output. Arterial blood pressure, total peripheral resistance, and aortic characteristic impedance were not affected by food restriction in middle-aged rats. However, adult food-restricted rats exhibited lower mean arterial blood pressure (99.1 +/- 3.1 mmHg) than did adult ad libitum-fed rats (110.7 +/- 3.0 mmHg). Total peripheral resistance was reduced from 0.645 +/- 0.045 mmHg-min-kg/ml in adult ad libitum-fed rats to 0.492 +/- 0.030 mmHg-min-kg/ml in adult food-restricted rats. Moreover, aortic characteristic impedance of adult food-restricted rats (0.014 +/- 0.001 mmHg-min-kg/ml) was lower than that of adult ad libitum-fed rats (0.024 +/- 0.002 mmHg-min-kg/ml). Neither age nor diet exerted effects on wave transit time and produced no changes in aortic distensibility. In conclusion, food restriction may elicit significant changes in the mechanical properties of both Windkessel vessels and resistance arterioles in adult rats, but not in middle-aged rats.

Age-related changes of arterial mechanical properties in rats: analysis using exponentially tapered T-tube model.

This study was designed to explore the changes of mechanical properties in the rat's arterial system at different ages by using the exponentially tapered T-tube model. Long-Evans male rats at the ages of 6, 12, and 18 months were anesthetized and thoractomized. Rats at the ages of 6, 12, and 18 months were individually referred to as young, adult, and middle-aged rats. The pulsatile pressure and flow signals in the ascending aorta were measured by a high-fidelity pressure sensor and electromagnetic flow probe, respectively. Model parameters, such as aortic characteristic impedance, vascular tapering index, wave transit time, and arterial load compliance, were inferred from the aortic pressure and flow signals to describe the pulsatile nature of blood flows in the vasculature. The static hemodynamic condition in those animals with different ages was characterized by (i) no change in cardiac output and (ii) a decrease in heart rate, arterial blood pressure, as well as total peripheral resistance. As for the pulsatile nature of the arterial system, the wave transit time remained unaltered, indicating there was no change in the aorta's distensibility of rats at those three different ages. The arterial load compliance, which describes the buffering nature of a hollow vessel, also remained unchanged. On the contrary, there was a significant fall in aortic characteristic impedance in those age-related rats. The decline of aortic characteristic impedance without a significant change in arterial distensibility suggests that lumen growth of the aorta and large arteries may occur in rats up to middle age.

Comparison of brain dopamine depletion induced by low-dose 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) in young and aged rats.

Effects of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) on dopamine levels in the striatum (ST), substantia nigra (SN), olfactory tubercle (OT), ventral tegmental area (VTA) and nucleus accumbens (NA) were studied in young (1 month) and old (21 months) male Long-Evans rats. Following repeated treatment with MPTP at low dose (3 mg/kg i.p. daily for 8 days) both young and old rats showed a marked depletion of dopamine (DA) concentrations in the ST compared to those of age-matched saline-treated controls. However, a significant reduction in DA levels was observed in the OT and NA of old but not young rats treated with MPTP. In contrast, no changes in 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) levels in these three regions were seen in either young or old MPTP-treated rats. However, the ratio of DOPAC/DA and HVA/DA in the ST and NA were significantly higher in old MPTP-treated rats than those in old controls. The concentrations of DA, DOPAC and HVA remained unchanged in the SN and VTA of both young and old rats after MPTP treatment. These results indicate that multiple treatment of low-dose MPTP selectively causes more widespread damage to dopaminergic neurons in old rats than in young ones, and further support the view that effects of MPTP on the dopaminergic system in rats may depend on age.

In vitro electro-pharmacological and autoradiographic analyses of muscarinic receptor subtypes in rat hypothalamic ventromedial nucleus: implications for cholinergic regulation of lordosis.

Muscarinic agonists can act through the hypothalamic ventromedial nucleus (VMN) to facilitate lordosis. To elucidate the neuronal mechanism(s) underlying this muscarinic facilitation, effects of muscarinic agents on the single-unit activity of VMN neurons recorded in brain tissue slices of estrogen-primed female rats were analyzed. All the agonists tested, including acetylcholine (ACh), oxotremorine-M (OM), carbachol (CCh) and McN-A-343 (McN), evoked primarily excitation (80-100%), some inhibition (0-20%) and occasional biphasic responses (0-8%). By comparing the response magnitude and the effectiveness in evoking a response, the rank order for evoking excitation, the primary response, was found to be: OM > CCh > ACh approximately McN, which is consistent with that (OM > CCh > McN) for facilitating lordosis reported by others. This consistency and the frequency of its occurrence suggest that the excitatory electric action of the muscarinic agonists is related to their facilitatory behavioral effect. Experiments with antagonists selective for M1 (pirenzepine), M2 (AF-DX 116) and M3 (4-DAMP and p-F-HHSiD) indicate that muscarinic excitations are mediated by M1 and/or M3, but not M2. Since M1 receptors have been shown to be neither sufficient nor necessary to mediate the muscarinic facilitation, M3 receptor may be crucially involved in this behavioral effect. Autoradiographic assays of binding to [3H]4-DAMP with or without pirenzepine and AF-DX 116, also indicate the presence of M3 receptors in the VMN. Quantitative analyses show that the M3 binding was not affected by the in vivo estrogen priming required to permit muscarinic agonists to facilitate lordosis. Thus, while the excitation mediated by M3 is likely to be involved in muscarinic facilitation of lordosis, the regulation of M3 receptor density does not seem to be involved in the permissive

Blockade of in vivo binding of 125I-labeled 3-iodobenzamide (IBZM) to dopamine receptors by D2 antagonist and agonist.

The in vivo binding of [125I]3-iodobenzamide (IBZM), a substituted benzamide, to DA receptor binding sites in the caudate nucleus, nucleus accumbens, and olfactory tubercle was investigated by using ex vivo autoradiography. The in vivo binding of IBZM seems to be selective to D2 dopamine receptors, since the binding was blocked by pretreatment of animals with D2 agonist LY-171555 or antagonist YM-09151-2. Furthermore, in vitro binding assays in striatal membranes confirmed that IBZM binding was highly selective to D2 sites. Thus, IBZM, when labeled with 123I (T1/2: 13h; 159 kev), could be a potential ligand for imaging D2 dopamine receptors by single photon emission computerized tomography procedures.

Recovery of high potassium-evoked dopamine release after depolarization challenge in the striatum of young and old male rats.

The aim of this study was to assess the recovery of high potassium-evoked dopamine (DA) release after depolarization challenge in young (3-4 months) and old (21-25 months) male Wistar rats. Recovery of DA release was evaluated by comparison of the peak responses of DA release induced by two serial high potassium stimulations. Concentric microdialysis probes were stereotaxically implanted in the lateral striatum of rats, and microdialysis was commenced 24 h after surgery. Using a low flow rate of perfusion (1 microl/min), all rats received 2 x 20 min infusions of 100 mM potassium solution separated by either 60 or 140 min. No difference in the basal DA concentration or the potassium-evoked DA release or its recovery was seen between the two groups. Our results suggest that the vesicular DA store recovers rapidly after high potassium challenge in both young and old rats.