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.

A microwave applicator for uniform irradiation by circularly polarized waves in an anechoic chamber

Microwave applicators are widely employed for materials heating in scientific research and industrial applications, such as food processing, wood drying, ceramic sintering, chemical synthesis, waste treatment, and insect control. For the majority of microwave applicators, materials are heated in the standing waves of a resonant cavity, which can be highly efficient in energy consumption, but often lacks the field uniformity and controllability required for a scientific study. Here, we report a microwave applicator for rapid heating of small samples by highly uniform irradiation. It features an anechoic chamber, a 24-GHz microwave source, and a linear-to-circular polarization converter. With a rather low energy efficiency, such an applicator functions mainly as a research tool. This paper discusses the significance of its special features and describes the structure, in situ diagnostic tools, calculated and measured field patterns, and a preliminary heating test of the overall system.

Stroke volume variation derived by arterial pulse contour analysis is a good indicator for preload estimation during liver transplantation

BACKGROUND

Accurate determination of preload during liver transplantation is essential. Continuous right ventricular end diastolic volume index (RVEDVI) has been shown to be a better preload indicator during liver transplantation than the filling pressures. However, recent evidence has shown that dynamic variables, in this case stroke volume variation (SVV), are also good indicators of preload responsiveness. In this study, we evaluated the correlation between SVV, which we derived from arterial pulse contour analysis and RVEDVI.

METHODS

In this study, we looked for possible relationships between SVV obtained through FloTrac/Vigileo monitor, central venous pressure (CVP), pulmonary arterial occlusion pressure (PAOP), and RVEDVI in 30 patients undergoing liver transplantation. Measurements were taken at 11 defined points during different phases across liver transplantation. Each set of measurement was taken during a steady state, which means at least 15 minutes elpased after any changes occured in either the infusion rate of catecholamines or ventilator settings. Pearson's test was used for correlation estimation.

RESULTS

There was a statistically significant (P<.01) relationship between SVV and RVEDVI with a correlation coefficient of -0.87. The correlations between CVP (r=0.42), PAOA (r=0.46), and RVEDVI were less strong.

CONCLUSION

We conclude that SVV is a good indicator for preload estimation during liver transplantation. A higher SVV value is associated with a more hypovolemic fluid status.

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.

Effects of internal medicine residency training in AIDS care in Taiwan

Having contact and interacting with HIV/AIDS patients has long been recognized as a means for improving AIDS-related knowledge and attitudes among physicians and hence for increasing their intention to provide AIDS care. To investigate the impact of one-month residency training in an AIDS inpatient unit on internal medicine residents, this quasi-experimental, pre-post, two-group study, conducted from April 2000 to April 2001, used questionnaires. At follow-up, residents who received training in the AIDS unit (experimental group) were significantly more knowledgeable about HIV/AIDS, had more positive attitudes and greater intention to care for HIV-infected patients than residents who did not receive this training (control group). Results suggest that a one-month AIDS residency training intervention can effectively enhance residents' HIV-related knowledge, attitudes and intention to care for patients infected with HIV.

Left cervical aortic arch with aneurysm and obstruction: three-dimensional computed tomographic angiography and magnetic resonance angiographic appearance

Cervical arch is a rare congenital anomaly presumed to result from persistence of the third aortic arch and regression of the normal fourth arch. Rather rare is cervical aortic arch associated with aneurysm and obstruction, with eight known cases reported. Definitive diagnosis with a noninvasive imaging modality is desirable and very important to prevent the need for disaster intervention. We present two cases of a pulsatile mass in the left supraclavicular region. Three-dimensional computed tomographic angiography and magnetic resonance angiography clearly showed a left-sided cervical aortic arch (Haughton type D) with arch aneurysm and coarctation (pseudocoarctation).

Hypotensive effects of captopril on physical properties of the arterial system in young and adult rats

We determined the acute effects of the angiotension converting enzyme inhibitor captopril on the arterial mechanics in rats at different ages, based on the exponentially tapered T-tube model. Male Wistar-Kyoto rats aged 4 and 12 months were individually referred to as young (n = 8) and adult rats (n = 8) and were anesthetized and thoractomized. The pulsatile aortic pressure and flow signals before and after the administration of captopril (20 mg/kg, i.p.) were measured by a high-fidelity pressure sensor and an electromagnetic flow probe, respectively. In each age group, captopril showed little change in basal heart rate as well as cardiac output. However, captopril produced a drop of 15% in mean aortic pressure in young and a fall of 12% in adult rats. In addition. captopril reduced total peripheral resistance by 21% in young and by 23% in adult animals. As for the pulsatile nature of the arterial system, captopril had increased wave transit time of the lower body circulation of 10% in young and of 12% in adult rats. By contrast, captopril reduced wave reflection factor by 22% in young and by 25% in adult animals. In conclusion, the converting enzyme inhibitor captopril has a stiffness-decreasing effect on Windkessel vessels and a dilated effect on resistance arterioles in either young or adult rats. No age dependence of vascular response and reflex tachycardia to captopril has been found in rats between 4 and 12 months.

Comparison of transcranial color-coded sonography and magnetic resonance angiography in acute ischemic stroke

BACKGROUND AND PURPOSE

This study was designed to assess the accuracy of transcranial color-coded sonography (TCCS) as compared to magnetic resonance angiography (MRA) for detecting intracranial arterial stenosis in patients with acute cerebral ischemia.

METHODS

The authors prospectively identified 120 consecutive patients admitted with acute ischemic stroke and performed both TCCS and MRA with a mean interval of 1 day. TCCS data (sampling depth, peak systolic and end diastolic angle-corrected velocity, mean angle-corrected velocity, and pulsatility index) for middle cerebral arteries (MCAs) were compared to MRA data and classified into 4 grades: normal (grade 1): normal caliber and signal; mild stenosis (grade 2): irregular lumen with reduced signal; severe stenosis (grade 3): absent signal in the stenotic segment (flow gap) and reconstituted distal signal; and possible occlusion (grade 4): absent signal. The cutoffs were chosen to maximize diagnostic accuracy.

RESULTS

Interobserver agreement for MRA grading resulted in a weighted-kappa value of 0.776. The rate of poor temporal window was 37% (89/240). Doppler signals were obtained in 135 vessels, and the angle-corrected velocities (peak systolic, end diastolic, mean) were significantly different (P = .001, P = .006, and P < .001) among the MRA grades: grade 1 (100, 47, 68 cm/s), grade 2 (171, 72, 110 cm/s), grade 3 (226, 79, 134 cm/s), grade 4 (61, 26, 39 cm/s). Additionally, an angle-corrected MCA peak systolic velocity > or = 120 cm/s correlates with intracranial stenosis on MRA (grade 2 or worse) with high specificity (90.5%; 95% confidence interval = 78.5%-96.8%) and positive predictive value (93.9%) but relatively low sensitivity (66.7%; 95% confidence interval = 61.2%-69.5%) and negative predictive value (55.1%).

CONCLUSION

Elevated MCA velocities on TCCS correlate with intracranial stenosis detected on MRA. An angle-corrected peak systolic velocity > or = 120 cm/s is highly specific for detecting intracranial stenosis as defined by significant MRA abnormality.

Intention of residents in internal medicine to care for patients infected with HIV at a university hospital in Taiwan

The purpose of this study was to investigate internal medicine residents' HIV-related knowledge and their attitudes towards caring for HIV-infected patients, and determine the extent to which these variables influence their care-providing intention. A cross-sectional survey was conducted in 56 internal medicine residents at a university hospital in Taiwan. Results showed residents' lack of sufficient knowledge was reflected by their inaccurate assessment of HIV-associated risk and their tendency to overuse protective gear in unnecessary situations. In general, residents expressed slightly positive attitudes with a neutral intention to care for HIV-infected patients. Knowledge and attitudes were significantly correlated with intention. The use of stepwise regression analysis revealed attitudes accounted for 59% of the variance in intention. Future efforts should focus on designing, implementing, and evaluating educational programmes that address residents' needs to ensure a solid HIV-related knowledge base, support their positive attitudes, address their ambivalent feelings toward providing HIV care, and enhance their intention to care for HIV-infected patients.

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.

Catecholamines in hyperpnoea-induced airway constriction of guinea pigs

1. We found previously that propranolol augments hyperpnoea-induced bronchoconstriction (HIB). This study was performed to investigate the underlying mechanism of this aug- menting action of propranolol. 2. In the first series, 45 young Hartley guinea-pigs were divided into five groups: control; propranolol; adrenalectomy; metoprolol and reserpine. Each animal underwent three periods: baseline, hyperpnoea, and recovery. For each animal 1 ml of arterial blood was sampled during the baseline and recovery periods. 3. Treatments of propranolol, metoprolol, and reserpine caused significant decreases in both dynamic respiratory compliance (Crs) and forced expiratory volume in 0.1 s (FEV0.1) during the baseline period. Hyperpnoea caused slight but not significant decreases in Crs, FEV0.1, and maximal expiratory flow at 50% total lung capacity (TLC) (V(max50)) during the recovery period in the control group. Propranolol, but not other treatments, significantly augmented these decreases (indicating HIB). Plasma noradrenaline and adrenaline levels in the reserpine group were not detectable. The above treatments or hyperpnoea did not induce any significant effect on the plasma noradrenaline level. Plasma adrenaline level of the control group was higher than that of either adrenalectomy or reserpine group during the baseline and the recovery periods. 4. In the second series, we avoided repeated blood samplings. Forty-eight animals were evenly divided into two groups: control and propranolol. Each group was again evenly divided into three subgroups: baseline; hyperpnoea, and recovery. Five minutes into the recovery period, we demonstrated HIB in the control group. In terms of V(max50), this HIB was significantly augmented by propranolol. Plasma noradrenaline and adrenaline levels, however, were not significantly altered by either hyperpnoea or propranolol. 5. Taken together, these data suggest that propranolol-augmented HIB has no direct relationship with decreased catecholamine activity.

Taiwanese nurses' attitudes about taking a sexual history

The purposes of this study were to explore Taiwanese nurses' beliefs, attitudes, and values about sexuality and to determine the extent to which these variables influence their attitudes toward taking a sexual history. A total of 391 nurses voluntarily participated in this study. The results of this study revealed that Taiwanese nurses hold moderate positive beliefs and slight positive attitudes and values about sexuality. They also expressed slight positive attitudes about taking a sexual history. The use of a regression analysis revealed that these nurses' beliefs, attitudes, and values about sexuality accounted for 9% of the variance in attitudes about taking a sexual history. Only beliefs and attitudes about sexuality were significant predictors of attitudes towards taking a sexual history. Strategies to change Taiwanese nurses' beliefs and attitudes about sexuality should be an essential nursing issue in practice and education.

Attenuation of paraquat-induced dopaminergic toxicity on the substantia nigra by (-)-deprenyl in vivo

(-)-Deprenyl (DEP) had been shown to slow of progression of Parkinson's disease (PD). The present study sought to determine whether DEP would attenuate the nigrostriatal system damage induced by intranigral administration of the herbicide paraquat (PQ) as a model of parkinsonism in vivo. Neurochemical and behavioral observations of Wistar rats were the focus of our study. In the neurochemical observation, the PQ injected in the rats caused dose-dependent depletion of dopamine (DA) in the ipsilateral striata. The coadministration of DEP with PQ partially increased the striatal DA level. The prediction of the striatal DA levels was calculated by regression coefficients obtained from multiple linear regression (r(2) = 0.82): DA level (% of control) = 103.34 - 9.58 PQ (nmol) + 0.79 DEP (nmol). It was demonstrated that the high dose of 20 nmol DEP could significant attenuate the PQ (5 nmol)-elicited dopaminergic toxicity (p < 0.05). In the behavioral observation, the intranigral injection of PQ into the rats caused a rotation behavior contralateral to the lesioned side in response to apomorphine administration (0.5 mg/kg, sc). This apomorphine-induced rotational behavior could also be attenuated significantly by coadministration of DEP (20 nmol) and PQ (5 nmol) compared with PQ-treated (5 nmol) animals (p < 0.05). The above observations indicate that DEP could provide a protective effect on the moderate injury elicited by PQ toxicity of the nigrostriatal dopaminergic system. DEP might be a useful therapeutic agent in treating patients with early-stage PD.

Involvement of apoptosis during deciduomal regression in pseudopregnant hamsters effect of progesterone

We determined whether fragmentation of genomic DNA, apoptosis, occurs during deciduomal regression in pseudopregnant hamsters and the effect of progesterone on the apoptotic processes. Artificially induced deciduoma were obtained on different days of pseudopregnancy and separated into mesometrial and antimesometrial tissues. The deciduomal cell cycle progression and population profiles of both sides were compared by flow cytometry. The proportion of sub-G1 peak, which was correlated with the apoptotic cells, were about 10% on day 8 and reached to 40% in both tissues on day 10. Exogenous progesterone treatment by daily injection (2 mg; s.c.) on and after day 8 reduced the percentage of low molecular weight DNA in both tissues on day 10 and day 12 as compared to the nontreated control one, respectively. The appearance of DNA ladder was also delayed at least 24 h by progesterone administration. The intensity of DNA fragmentation was more pronounced in antimesometrial deciduoma. In situ 3'-end labeling of apoptotic cells further substantiated the apoptotic process. The apoptotic cells first appeared in the luminal region in antimesometrial deciduoma on day 8 and spreaded all over the entire deciduomal tissue on day 10. Progesterone treatment stimulated deciduomal proliferating cell nuclear antigen (PCNA) expression, maintained deciduoma until day 14 and retarded the differentiation and regeneration of the uterine epithelium.

Esophageal varices in congenital heart disease with total anomalous pulmonary venous connection

Total anomalous pulmonary venous connection (TAPVC) is an uncommon congenital anomaly in which the anatomical presentations vary widely among patients. We hereby present two newborns with TAPVC associated with asplenia syndrome; both had severe esophageal varices due to infradiaphragmatic pulmonary venous drainage. Ultrafast computed tomography (CT) scanning was superior to color Doppler echocardiography and cardiac catheterization as it provided a detailed portrait of the pulmonary drainage. The remarkable radiographic manifestations are presented.

Striatal glutamate release during novelty exposure-induced hyperactivity in olfactory bulbectomized rats

Striatal glutamate release during novelty exposure-induced hyperactivity was studied by microdialysis in freely-moving olfactory bulbectomized (OBX) rats. After collecting three 10 min basal striatal dialysate samples, the animals were transferred to an open-field apparatus (novelty) and locomotor activity recorded for 60 min. OBX rats showed significantly more locomotor activity (1210+/-270 cm) than sham-operated rats (420+/-70 cm), but only in the first 10 min after exposure to the novel environment. During the same period, striatal glutamate levels increased to 163+/-21% of the basal value in OBX rats, while no changes were seen in the striatum of sham-operated controls. These findings suggest that olfactory bulbectomy results in an increased response of the striatal glutamatergic system to novelty stress, and may consequently cause hyperactivity.

Stressors of living with HIV/AIDS: patients' perspectives

With the prospect of increasing numbers of patients with human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS), healthcare professionals (professionals) need to be better informed about patients' perspectives in order to provide efficacious, compassionate, and efficient care to patients. In Taiwan, the biomedical research and healthcare professionals' perspectives have dominated research related to HIV/AIDS. The purpose of the study was to investigate the stressors experienced by patients which have, thus far, been under-explored. This study used a phenomenological approach to gain insight into the patients' experience. In-depth, open-ended interviews were used to collect data. Interviews were tape recorded and transcribed verbatim to maintain data integrity and to reduce perceptual bias. The open coding procedure was used to analyze the interview transcripts. Study participants were 14 male patients with an average age of 35.71 year-old, who had known their positive HIV status for an average of 24.9 months. Patients experienced multiple stressors because of having the life threatening illness of HIV/AIDS. Their stressors were identified as follows: being confronted with the diagnosis, fear of disclosure, unpredictability of their physical condition, hypervigilance toward physical symptoms, emotional upheaval, and constrained life planning. The findings of this study form the basis for professionals to design services particularly addressed to patients' needs, for example, informed testing, and pre- and post-counseling. Further efforts could focus on developing systemic intervention programs to help patients better cope with the challenges of living with HIV/AIDS.

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.

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.

Falls in a psychiatric unit

The purposes of this descriptive study were to document the prevalence of previously identified risk factors for falls in a group of acutely ill psychiatric patients, to determine if patients who fell differed from nonfallers with respect to risk factors, and to describe the circumstances surrounding falls that occurred on an inpatient unit. All patients admitted to an acute psychiatric unit during a 7-month period were entered into the study (N = 197). Twice a day, nurses who worked on the unit completed a fall-risk factors checklist for each patient. When a fall occurred, an additional instrument designed to measure circumstances associated with the fall was completed. The most frequently occurring risk factors were clinical diagnoses of depression and confusion or disorientation. Seventeen patients fell during their hospitalization. Compared with nonfallers, patients who fell were more likely to have a previous history of falls, generalized weakness, confusion or disorientation, difficulty with mobility or walking, elimination problems, and temperature elevation. Analysis of circumstances surrounding falls showed that the majority of falls occurred when patients were attempting to get out of bed, walk to the bathroom at night, or change from a sitting to a standing position. Findings from this research can be used to identify psychiatric patients who are at risk for falls during their hospitalization.

Male sexual behavior is associated with LHRH neuron number in middle-aged rats

LHRH administration is reported to facilitate male sexual behavior. The aim of the present study was to investigate whether male sexual behavior is associated with the number of LHRH neurons in the forebrain in middle-aged rats. Male Long-Evans rats (18-19 months) were assigned to three groups on the basis of sexual performance: (1) group MEI consisted of rats showing complete copulatory patterns, including mounts, intromissions and ejaculations, (2) group MI was composed of rats showing mounts and intromissions, but no ejaculation and (3) group NC were non-copulators, i.e. they did not show any copulatory behavior. Young adult rats (4-5 months), displaying sexual behavior, were used as controls. Following the sexual behavior tests, the number of LHRH neurons in the medial septum (MS), organum vasculosum of the lamina terminalis (OVLT), preoptic area (POA) and anterior hypothalamus (AH) was determined by immunocytochemistry. No difference was seen in the total number of LHRH neurons in these combined brain areas between group MIE and young controls. In the three middle-aged groups, the total number of LHRH neurons was greatest in group MIE, less in group MI, and lowest in group NC. In general, a similar trend was seen separately in the MS, OVLT and POA. These results suggest that changes in the number of LHRH neurons in the forebrain, in most cases, are age-related, at least in the middle-aged rats, but they also seem to be associated with male sexual performance.

Restoration of sexual behavior in aged male rats by intracerebral grafts of fetal preoptic area neurons

A decline in sexual arousal and copulatory activity has been observed in male rats with advancing age. Grafting of fetal hypothalamic tissue into the third ventricle of aged male rats restores sexual behavior. This study investigated the effects of grafting fetal preoptic area (POA) neurons into the POA of aged male rats exhibiting decreased sexual behavior. We grafted suspensions of fetal POA neurons into the POA of 20 aged (19 to 24 months old) male rats that displayed no ejaculation. From 2 weeks after grafting, one or more series of male copulatory activity and sexual motivation tests were performed at intervals of 3 to 4 weeks. Three behavioral tests given 5 days apart were repeated for each animal in each series. Among the 20 aged rats with the fetal grafts, 15 showed improved sexual motivation, and 14 of these had copulatory activity restored to levels comparable with those of young males. Among these 14 rats, eight ejaculated during copulation. Copulatory behavior was restored between 21 and 45 days after grafting and persisted until the end of observation (2-4.5 months). Sexual performance did not improve in control aged male rats grafted with either fetal cerebral cortex neurons into the POA or POA, neurons into the ventromedial hypothalamus. The rats that received grafts of fetal POA neurons into the POA and recovered sexual performance also showed improvement or recovery to levels comparable to those in young males of serum testosterone concentrations, serum luteinizing hormone levels after castration, and the post-castration rise in luteinizing hormone. These results indicate that decreases in copulatory activity, sexual motivation, and some neuroendocrine functions in aged male rats are at least partially due to dysfunction of the POA.

Effects of paraquat on the substantia nigra of the wistar rats: neurochemical, histological, and behavioral studies

Effects of paraquat on the substantia nigra of the male Wistar rats we re studied pharmacologically by a intracerebral injection of paraquat. The neurochemical, morphological, and behavioral changes observed after a unilateral intranigral injection of paraquat (1-5 microgram) were as follows: (1) neurochemically, paraquat caused dose-dependent depletion of dopamine in the ipsilateral striatum starting 2 weeks after treatment; this effect was long-lasting and irreversible. The ipsilateral striatal dopamine level in animals treated with 3 microgram paraquat was even decreased by 91.5%. (2) Morphologically, 2 microgram of paraquat produced marked loss of Nissl substances and prominent glial reaction in the substantia nigra, while 3 microgram of paraquat caused a severe loss of neurons. (3) Behaviorally, paraquat caused a vigorous rotational behavior in rats contralateral to the lesioned side in response to apomorphine administration (0.5 mg/kg, sc). This effect was dose-dependent and lasted for the entire 16-week experimental period. Taken together, these data indicate that intranigrally injected paraquat may possess marked neurotoxicity and induce degeneration of the rat nigrostriatal dopaminergic system.

Dopamine release in the nucleus accumbens during sexual behavior in prenatally stressed adult male rats

In vivo microdialysis experiments were performed on the nucleus accumbens (NAc) during observation of sexual behavior (including motivation and copulation) to determine if there were any changes in NAc dopamine (DA) transmission in prenatally stressed (PS) adult male rats. Approximate 37% of control males and 83% of PS males did not exhibit copulation during the sexual behavior tests and no significant changes in NAc DA release were seen during exposure to estrous females. In contrast, both control and PS males that displayed copulatory behavior showed a marked increase in NAc DA release when presented with a sexually receptive female behind a screen and this increased further during actual copulation. The increase in DA release in copulatory PS males was not significantly different from that in sexually active control males. In addition, a similar extent in DA release induced by high potassium perfusate was observed in all rats. These results suggest that prenatal stress may result in a deficit in DA neurotransmission in the NAc and this deficit may possibly cause impaired male sexual behavior in rats.

Effects of age on dopamine release in the nucleus accumbens and amphetamine-induced locomotor activity in rats

The effects of age on dopamine (DA) release in the nucleus accumbens (NAc) and on amphetamine (AMPH)-induced locomotor activity were studied by microdialysis in freely-moving young (5 month) and old (24 month) rats. Both basal extracellular DA and 3,4-dihydroxyphenylacetic acid (DOPAC) release and that following intra-accumbens perfusion of AMPH (1-10 microM) were significantly lower in old rats. After intraperitoneal injection of AMPH (1.5 mg/kg), no age-related change in DA release was seen in the NAc, but locomotor activity was found to increase much more in young rats than in old ones. These results indicate that (1) old rats show decreased extracellular DA and DOPAC release, both in the basal state and following intra-accumbens infusion of AMPH, and (2) the age-related locomotor activity induced by systemic injection of AMPH is not paralleled by changes in DA release in the NAc.

Predictors of Taiwanese nurses' intention to care for patients who are HIV positive

The purpose of this research was to explore the knowledge of, attitudes toward, and intention to care for HIV-positive patients among 223 Taiwanese nurses. They worked in many different settings and had a variety of levels of exposure to HIV-positive patients. The findings of this research revealed that most Taiwanese nurses lacked sufficient knowledge to prevent themselves from becoming infected in the workplace. Their attitude about giving care to HIV-positive patients was generally negative; most nurses stated that they did not intend to care for these patients. A regression analysis revealed that knowledge was not a significant predictor of intention. Attitudes about societal treatment of HIV-positive people and nursing care were significant predictors of intention. Implications for practice and education of Taiwanese nurses are discussed.

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

Effects of fetal brain grafting on adult behavioral masculinization and defeminization in neonatally androgenized female rats

Treatment of neonatal female rats with androgen results not only in decreased female sexual behavior but also in enhanced male sexual behavior examined in adulthood. The effects of grafting fetal preoptic area (POA) neurons into the POA, and fetal hypothalamic (HPT) neurons into the ventromedial hypothalamus (VMH), were tested in neonatally androgen-sterilized rats (ASR). The rats were injected subcutaneously with 80 micrograms testosterone propionate within the 24 hours after birth to see if sexual behavior could be normalized by fetal brain grafts. In repeated tests on ASR grafted with fetal HPT into the VMH, the lordotic response was seen to increase to the level seen in non-ASR controls, while the increase in mounting behavior in ASR was suppressed following grafting of fetal POA or cerebral cortex into the POA. These results suggest that there are dysfunctions of POA and VMH in ASR, and that the dysfunctions revealed by sexual behavior can be overcome by fetal POA or HPT grafting.

Age-related changes in the pattern of luteinizing hormone release induced in female rats by male rat urine

The release of luteinizing hormone (LH) in young (3-4 months) and aged (24-25 months) ovariectomized female Sprague-Dawley rats, s.c. implanted with a 17 beta-estradiol benzoate silastic capsule, was studied in the presence and absence of stimulation by exposure to male rat urine. After taking an initial blood sample at 12:00 (reference sample), either urine, collected from young adult male rats, or distilled water was poured into the female's cage. Blood samples were then collected hourly up to 18:00 via a catheterized jugular cannula. The concentration of LH in the plasma was measured by RIA. The basal plasma LH level in young control rats was found to increase significantly at 16:00 compared with the 12:00 reference sample while no statistically significant change in plasma LH concentration occurred in old controls over the same period. Male rat urine caused a significantly earlier (at 15:00) and prolonged (from 15:00 to 18:00) elevation of plasma LH in young rats compared with young controls. In contrast, exposure of old female rats to male rat urine resulted in no marked change in plasma LH levels. These results suggest that both basal LH release and the response to pheromonal stimulation by male rat urine may be modified with increasing age in female rats.

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.

[Bronchopleural fistula in a newborn: report of one case]

Persistent pneumothorax is infrequently seen in the neonate. Persistent pneumothorax with a large air leak and empyema may indicate the presence of a bronchopleural fistula which often results in mortality in infants requiring ventilator support. A ten-day-old female neonate with meconium aspiration syndrome was found to have respiratory distress after birth. During ventilator therapy, persistent pneumothorax with a large air leak from the chest tube was found. Empyema occurred three days later. Despite insertion of multiple chest tubes and use of bronchial balloon occlusion, a large air leak and empyema still were noted. Following thoracotomy and suture of the bronchopleural fistula, the air leak stopped. The patient was smoothly weaned from the ventilator. She was able to be discharged in good condition six weeks later. In management of the bronchopleural fistula, bronchial balloon occlusion enabled the patient to be maintained until more specific therapy could be attempted. Thoracotomy is definite therapy for selected infants requiring ventilator support who demonstrate a large air leak, persistent pneumothorax, and progressive hypoxia which is unresponsive to chest tube insertion.

Changes in sleep patterns by intralaminar thalamic microinjection of fluoxetine in rats

Sleep patterns were investigated in rats by analysis of EEG recorded for 6 hours following fluoxetine or saline (control) microinjection into the centromedial intralaminar thalamus (CIT) at either 9:30 AM or 1:30 PM, 4 or 8 hours after lights on, respectively. The treatment of fluoxetine at 9:30 AM did not affect any sleep patterns. In contrast, fluoxetine significantly suppressed total paradoxical sleep (PS) time and the number of PS episodes during the second and third hour after administration at 1:30 PM. In addition, microinjection of fluoxetine produced an apparent enhancement of the duration of slow wave sleep (SWS) episodes and a small non-significant increase in total SWS time. On the other hand, no obvious changes in the basal sleep-wakefulness pattern were found between the two saline-treated control groups. These results indicate that CIT microinjection of fluoxetine at different time points acts differentially in sleep patterns and suggest that CIT may be one of the action sites for peripherally administered fluoxetine to alter sleep patterns.

Age-related effects of MPTP on norepinephrine concentrations of various areas of rat brains

The effects of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) on the norepinephrine (NE) levels of 11 areas of rat brains were investigated. Male Long-Evans rats, aged 4 weeks (young group) and 21 months (old group), were injected intraperitoneally (i.p.) with MPTP (3 mg/kg) daily for 8 days. Control rats received an i.p. injection of saline. Rats were sacrificed 24 h after the last injection. NE in various brain areas were assayed by high pressure liquid chromatography with electrochemical detection. Multidose treatment of MPTP caused no alteration of levels of NE in any brain area of young rats. In contrast, a marked increase in concentration of NE was found in locus coeruleus, dorsal raphe nuclei and amygdala of old rats. These results indicate that MPTP selectively causes lesions in the noradrenergic system of rats and that the neurotoxic effects of MPTP in rats may depend on age.

Age-related changes in locomotor behavior induced by MPTP in rats

Effect of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) on gait was studied in young (4 weeks) and old (21 months) male rats. No significant alteration in stride length (SL) or stride width (SW) was observed 30 min after single dose MPTP treatment (3 mg/kg, i.p.) in both young and old rats. Multidose treatment with MPTP (3 mg/kg, i.p. daily for 8 days) resulted in a marked decrease in SL in old rats compared to that of old control group, while an increase in SL was found in both MPTP-treated and control young rats. In contrast, multidose MPTP administration caused no changes in SW in either young or old rats. The present result of behavioral analysis suggests that multidose MPTP neurotoxic effect on locomotor activity may be age dependent in rats and that the old rat is an appropriate model for MPTP studies.

Effects of male rat urine on norepinephrine levels in the accessory olfactory bulb of young and aged female rats

Norepinephrine (NE) concentrations in the accessory olfactory bulbs (AOB) of young (4-5 months) and old (25-26 months) ovariectomized Sprague-Dawley rats, which were implanted with a 17 beta-estradiol silastic capsule and then exposed to male rat urine, were studied. The unilateral vomeronasal organ was removed in all rats one week before exposure to the urine stimulation. The NE level in the AOB of this surgical side served as the control. Urine collected from young adult male rats was poured into the female's cage at 12:00h and the animals were sacrificed before and 1, 2, or 3 hours after the male urine was given. The NE basal levels in the AOB of young rats decreased significantly at 14:00h compared to those at 12:00h, while no obvious changes in the NE concentrations were observed in the AOB of old rats during the same period. Two hours after continuous exposure to male urine, the NE concentrations in the AOB of young rats markedly increased, but no similar response occurred in the old rats. These data suggest that the noradrenergic functions in the AOB under basal conditions as well as in response to pheromonal stimulation may be modified with increasing age.

Norepinephrine levels in the vomeronasal system and their responses to male urine in young and aged female rats

Norepinephrine (NE) levels in brain areas of the vomeronasal system in young (4-5 months) and aged (25-26 months) ovariectomized Sprague-Dawley rats, which were implanted with a 17 beta-estradiol silastic capsule and then exposed to male rat urine, were investigated. The unilateral vomeronasal organ was removed in all rats one week before exposure to urine stimulation. NE levels in the medial nucleus of the amygdala (MA), medial preoptic area (MPOA), ventromedial nucleus of hypothalamus (VMH) and bed nucleus of stria terminalis (BST) were measured. NE concentrations in these brain areas of the surgical side served as the control. Urine collected from young adult male rats was poured into the female's cage at 12:00h and the animals were sacrificed before and 1, 2, or 3 hours after the male urine was given. The NE basal levels in the MA and MPOA of young rats decreased significantly from 13:00h to 15:00h, and those in young rat VMH declined markedly from 13:00h to 14:00h compared to those at 12:00h. No marked alterations in NE basal levels in young rat BST were found. In contrast, no obvious changes in the NE concentrations were observed in these brain areas of old rats. Continuous exposure to male urine did not affect the NE levels in any of these brain areas of young and aged rats. We concluded that (1) the time-dependent fluctuation of the NE basal levels in some brain areas of the vomeronasal system in female rats is age-related, and (2) the NE in all these nuclei of the vomeronasal system is not involved in pheromone-induced effects.

Effects of long-term dietary restriction on body temperature are modified with increasing age

Effects of long-term dietary restriction on body temperature and its circadian changes were investigated in 3.5- and 14.5-month-old male Long-Evans rats. Animals were either fed and libitum or kept on a restricted diet for 8 weeks. Purina Lab Chow was constantly available to the ad libitum-fed groups, while half portions of their daily food consumption were given to age-matched diet-restricted groups every day. A highly significant lowering of body temperature in middle-aged diet-restricted (MR) rats was not observed until their food intake had been restricted for 5 weeks compared with that of the middle-aged ad libitum-fed (MA) group as well as that of the young diet-restricted (YR) rats. Eight weeks after diet restriction, both the circadian pattern of body temperature and its diurnal peak-trough difference remained almost unchanged in all four groups, while the average body temperature of MR rats was greatly lower than that of the YR group and that of MA animals. No significant difference in average body temperature was found between the young ad libitum-fed (YA) rats and the MA group. These data suggest that the average body temperature and its circadian changes in ad libitum-fed rats, at least before the age of 14.5 months, is not age-related, while the effect of dietary restriction on body temperature may be modified with increasing age.

Influence of long-term continuous illumination on the nuclear volume of hypothalamic neurons in female rats

A light microscopic quantitative analysis was performed for studying the effects of long-term exposure to continuous illumination on hypothalamic morphology in female rats. Nuclear volumes of neurons in the suprachiasmatic nucleus, paraventricular nucleus, ventromedial nucleus and preoptic area were measured in 16-18 month-old Long-Evans female rats which had been exposed to continuous light for 11 months. Significant nuclear volume shrinkage could be observed in all investigated regions except for the preoptic area in these animals when compared to that of control rats kept under a photoperiod of 14h light and 10h dark. The relationship between morphological changes of hypothalamic neurons and the marked alteration of melatonin and estrogen levels induced by long-term exposure to continuous light is discussed.

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.

In vitro binding properties and autoradiographic imaging of 3-iodobenzamide ([125I]-IBZM): a potential imaging ligand for D-2 dopamine receptors in SPECT

The in vitro binding properties of the [125I] labeled benzamide (S(-)-N-[(1-ethyl-2-pyrrolidinyl)-methyl]-2-hydroxy-3-iodo-6-methoxy- benzamide, IBZM) were determined in bovine and mouse caudate membrane homogenates and by autoradiography of mouse brain slices. [125I]-IBZM binding is saturable and reversible with a Bmax of 373 +/- 51 fmol/mg protein and a Kd of 3.1 +/- 0.62 nM (mean +/- SD, Scatchard analyses) and 0.56 nM as calculated by association and dissociation time constants. In competition experiments, Ki values for the D-2 antagonists YM-09151-2 and spiperone are 4 orders of magnitude lower than the Ki value for the D-1 antagonist SCH-23390 and S(-)-IBZM is ten-fold more potent than R(+)-IBZM. [125I]-IBZM has a low affinity for serotonin S-2 and for alpha receptors. Therefore, it is a highly selective ligand for dopamine D-2 receptors. Autoradiographic images of brain sections incubated with [125I]-IBZM show the dopamine D-2 receptors of the striatum, nucleus accumbens and olfactory tubercle with a high ratio of specific to nonspecific binding. Thus, S(-)-IBZM, when labeled with [123I], may be useful for in vivo imaging of dopamine D-2 receptors by single photon emission computerized tomography (SPECT).