Distributions of different types of nociceptive neurons in thalamic mediodorsal nuclei of anesthetized rats

Mediodorsal thalamic nucleus (MD) is a critical relay of nociception. This study recorded responses of MD neurons to noxious mechanical and thermal stimuli in isoflurane anesthetized rats. We found the threshold of noxious mechanical stimulation was 141 gw and that of noxious heat stimulation was 46 °C. A significantly higher percentage of noxious inhibitory neurons were found in the medial and central part of the MD, whereas a higher percentage of noxious excitatory neurons were found in the lateral part of the MD and adjacent intralaminar nuclei. The differential distribution of excitatory and inhibitory neurons implies functional differentiation between the medial and lateral part of the MD in nociception processing. Furthermore, by an analysis of the stimulus-response function (SRF), we found 80% of these excitatory neurons had a step-function or hat-shape-like SRF. This suggests that most of the MD neurons may serve as a system to distinguish innocuous versus noxious stimuli.

Motor function in an animal model with ouabain-induced bipolar disorder and comorbid anxiety behavior

In a clinical setting, anxiety disorder is highly correlated with bipolar I disorder in humans. However, the comorbidity of anxiety behavior and bipolar disorder still remains unclear in an animal model. This study utilized an ouabain-induced animal mode to examine anxiety and mania in an open field test. In the present study, 5 µl of artificial cerebrospinal fluid (aCSF) or ouabain (10^-5, 10^-4, and 10^-3 M) were administered into the left ventricle. The animals' motor functions and anxiety behaviors were measured for 15 min. The results showed that 10^-3 M ouabain significantly increased the animal's total distance traveled, average speed, and maximum speed compared to the control group. The time spent inside (i.e., how much time rats spent in the center of the square) and the inside-outside times of the central square (i.e., how many times rats ran across the center square) of the higher-concentration groups (10^-4 M and 10^-3 M) were significantly decreased. Therefore, a high concentration of ouabain may induce hyperactivity. The 10^-4 M and 10^-3 M ouabain groups exhibited more anxiety behaviors. The study is the first model to examine comorbid anxiety behaviors and bipolar disorder in an animal model. The study provides some insights for comorbid anxiety and bipolar disorder in clinics.

NMR-based metabolomics for the environmental assessment of Kaohsiung Harbor sediments exemplified by a marine amphipod (Hyalella azteca)

Inflow of wastewater from upstream causes a large flux of pollutants to enter Kaohsiung Harbor in Taiwan daily. To reveal the ecological risk posed by Kaohsiung Harbor sediments, an ecological metabolomic approach was employed to investigate environmental factors pertinent to the physiological regulation of the marine amphipod Hyalella azteca. The amphipods were exposed to sediments collected from different stream inlets of the Love River (LR), Canon River (CR), Jen-Gen River (JR), and Salt River (SR). Harbor entrance 1 (E1) was selected as a reference site. After 10-day exposure, metabolomic analysis of the Hyalella azteca revealed differences between two groups: {E1, LR, CR} and {JR, SR}. The metabolic pathways identified in the two groups of amphipods were significantly different. The results demonstrated that NMR-based metabolomics can be effectively used to characterize metabolic response related to sediment from polluted areas.

Social factors affect motor and anxiety behaviors in the animal model of attention-deficit hyperactivity disorders: A housing-style factor

The present study examines whether housing style (e.g., single housing, same-strain-grouped housing, and different-strain-grouped housing) and rat strain (e.g., spontaneous hypertension rats [SHR] and Wistar-Kyoto rats [WKY]) mediate motor function and anxiety behavior in the open field task. From week 4 through week 10 following birth, the rats were measured 30min for locomotor activity and anxiety once per week in the open field task. The SHR rats exhibited hyperactivity in total distance traveled and movement time to form the animal model of ADHD. The SHR rats spent more time inside the square and crossed the inside-outside line more often than the WKY rats, indicating the SHR rats exhibited less anxiety behavior. The different-strain-grouped housing style (but neither the same-strain-grouped housing style nor the single housing style) decreased total distance traveled and facilitated anxiety behavior. The motor function was negatively correlated with anxiety behavior for SHR rats but not for WKY rats. Housing styles had a negative correlation between motor function and anxiety behavior. The present findings provide some insights regarding how social factors (such as housing style) affect motor function and anxiety behavior related to ADHD in a clinical setting.

Transparent Memory For Harsh Electronics

As a new class of non-volatile memory, resistive random access memory (RRAM) offers not only superior electronic characteristics, but also advanced functionalities, such as transparency and radiation hardness. However, the environmental tolerance of RRAM is material-dependent, and therefore the materials used must be chosen carefully in order to avoid instabilities and performance degradation caused by the detrimental effects arising from environmental gases and ionizing radiation. In this work, we demonstrate that AlN-based RRAM displays excellent performance and environmental stability, with no significant degradation to the resistance ratio over a 100-cycle endurance test. Moreover, transparent RRAM (TRRAM) based on AlN also performs reliably under four different harsh environmental conditions and 2 MeV proton irradiation fluences, ranging from 10¹¹ to 10¹⁵ cm^-2. These findings not only provide a guideline for TRRAM design, but also demonstrate the promising applicability of AlN TRRAM for future transparent harsh electronics.

Abstract P5-16-21: The association of higher tumor HER2 load with treatment response to neoadjuvant therapy in HER2 positive breast cancer patients

Background: Neoadjuvant therapy for HER2 positive invasive breast cancer is used to downstage tumor prior to surgery, objectively measure response, and evaluate novel therapies in clinical trials. Residual Cancer Burden (RCB) established by pathologic evaluation of post-treatment surgical specimens is a marker of tumor response to chemotherapy as well as predictor of recurrence-free survival in HER2 positive breast cancer. The relationship between the HER2 tumor load and the response to chemotherapy in not known.

Specific Aims: To evaluate RCB after neoadjuvant chemotherapy and HER2-targeted treatment for HER2-positive breast cancer, and to determine clinicopathologic factors associated with treatment response as represented by RCB.

Methods: This retrospective chart review included all HER2-positive breast cancer patients, stage I – III, receiving neoadjuvant chemotherapy and HER2-targeted therapy with post-treatment surgical resection at an Allina Health hospital from 2013-2016. Review of clinicopathologic variables included HER2/CEP17 ratio, HER2 absolute copies, ER/PgR status (using the H score calculation), patient age, baseline tumor size, and gross and microscopic pathology review of breast tissue specimens with RCB evaluation completed by breast pathologists. To compare factors related to response, chi-square with Monte-Carlo simulation was used to analyze dichotomous variables, and Mann Whitney U-tests were used for continuous variables.

Findings: The study included 97 patients. Upon surgical resection, complete pathologic response (RCB-0) was found in 47% (46/97 patients), and partial pathologic response (RCB-I) in 15% (15/97 patients). As compared to non-responders (RCB-2 and RCB-3) the complete and partial responders (RCB-0 and RCB-1) were associated with greater HER2/CEP17 ratios (10.2 vs. 6.5; p=0.003), and greater HER2 absolute copies (25 vs. 15.8; p <0.001). Complete responders were associated with lower ER expression (H scores of 89.2 vs. 171.8; p=0.005) than non-responders, with RCB-1 responders associated with ER H-scores between RCB-0 and non-responders (H score=145.9). No significant differences were noted between responders and non-responders on age at diagnosis, pre-treatment tumor size, PgR expression, or the percentage of tumor infiltrating lymphocytes.

Conclusions: The majority of patients with HER2 positive tumors show considerable benefit with neoadjuvant chemotherapy and HER2-targeted treatment (63% in our study) based on RCB assessment. Predictors of response as measured by RCB include high HER2/CEP17 ratios, high absolute copies of HER2 signals by FISH, and lower ER expression.

Citation Format: Lillemoe TJ, Susnik B, Grimm E, Kang S-HL, Swenson KK, Krueger JL, Finkelstein MJ, Tsai ML. The association of higher tumor HER2 load with treatment response to neoadjuvant therapy in HER2 positive breast cancer patients [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-16-21.

Abstract P3-02-02: Predictive value of breast MRI in detecting mammographically occult contralateral breast cancer: Can we target women more likely to have contralateral breast cancer based on primary tumor clinicopathologic factors?

Background: Use of preoperative magnetic resonance imaging (MRI) staging in newly diagnosed breast cancer increases detection of synchronous contralateral breast cancer (CBC) over other screening modalities; however, it is associated with a high false positive rate, additional biopsies, extensive surgical procedures, and possibly increased psychological morbidity.

Specific Aims: To determine predictors of synchronous, mammographically-occult but MRI-detected CBC in women newly diagnosed with breast cancer.

Methods: We performed a retrospective review of patients at Allina Health, Abbott Northwestern Hospital who had preoperative breast MRI prior to surgical resection of their breast cancer from 2010–2014. We collected patient demographic and clinicopathologic data. To determine the association between MRI-detected CBC versus benign findings based on clinicopathologic data, we performed univariate analysis (p<0.05). Multivariate Logistic Regression was used to adjust for covariates and factors predictive of CBC. Area under the Receiver Operating Characteristic Curve provided a measure of model accuracy.

Findings: 1894 patients had pre-operative MRI during the study period. Of those, 201 had suspicious findings on contralateral breast MRI requiring biopsy (table 1). Overall 3% (60/1894) had synchronous CBC (invasive carcinoma or DCIS) detected on MRI. The majority of CBCs (n=60) were stage 0 or IA (85%), ER/PgR+ (98%), HER2- (89%), and low/intermediate grade (80%). Women more likely to have mammographically-occult CBC were older (p<0.001), had lobular versus ductal index cancer (p=0.03), and had ER positive (p=0.027) or PgR positive (p=0.002) tumors. On multivariate logistic regression analysis (ROC area=0.75), PgR positive status (p=0.022), and older age (p=0.004) were predictive of CBC. With each year of additional age, odds of CBC increased by 5%. No CBC was identified in women < age 45 with high risk index cancers (ER- or HER2 +). CBC was 11 times more likely when PgR status was positive versus negative. CBCs were diagnosed significantly more frequently in patients with index cancers that were hormone receptor positive and HER2 negative compared to HER2 positive or triple negative invasive index cancers (Fisher's exact test; p=0.041).

Risk of CBC by Index Cancer TypeIndex CancerCBC n (%)DCIS (n=51)15 (29)Invasive carcinoma (n=150)45 (30)ER+/HER2- (n=121)41 (34)HER2 positive (n=18)3 (17)Triple Negative (n=11)1 (9)Total (n=201)60 (30)

Conclusions: Preoperative MRI is effective in detecting mammographically-occult early stage, hormone receptor positive CBC in older women. MRI-detected CBC is more common in patients originally presenting with hormone receptor positive and HER2 negative index cancers. Our results suggest that it may be possible to determine a subset of patients who are less likely to benefit from a preoperative breast MRI, an important implication in an era of increasing healthcare cost utilization awareness.

Citation Format: Susnik B, Lillemoe TJ, Swenson KK, Tsai ML, Finkelstein MJ, Schneider L, Braatz CM, Krueger JL, Rueth N. Predictive value of breast MRI in detecting mammographically occult contralateral breast cancer: Can we target women more likely to have contralateral breast cancer based on primary tumor clinicopathologic factors? [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-02-02.

Spatiotemporal Changes of Neuronal Responses in the Primary Somatosensory Cortex to Noxious Tail Stimulation in Awake and Pentobarbital-Anesthetized Rats

Primary somatosensory cortex (SI) is a key area in the processing of nociceptor inputs to our consciousness. To clarify the columnar and laminar organization of SI for pain processing, we compared spatiotemporal changes in neuronal activities of the primary sensorimotor cortex (SmI) of the rat in response to noxious laser heat stimulation applied to the mid-tail. Longitudinal and vertical array microelectrodes were chronically implanted in the cerebral cortex. Evoked neuronal activities, including intracortical local field potentials (LFP) and ensemble single-unit activity (SU) around SmI were simultaneously recorded. The effect of pentobarbital on the neuronal responses was evaluated in comparison with the neuronal responses in conscious animals to explore the potential substrate of nociceptive processing in the conscious state. The results from the experiment with longitudinal microelectrode arrays indicated that noxious stimulation induced a neuronal response which was spread widely around the SmI of the conscious rat, and the range of neuronal responses was limited to the tail region of the SmI under anesthesia. The results from the experiment with vertical microelectrode arrays showed the universal neuronal responses through all cortical layers of the SmI in conscious rats, and sodium pentobarbital suppressed these neuronal responses in the supragranular layers significantly relative to the deeper layers and basal activity. These results imply that a wider range of cortical activation, both in the horizontal or vertical dimension, might be important for nociceptive processing in the conscious state.

Plasticity of cerebellar Purkinje cells in behavioral training of body balance control

Neural responses to sensory inputs caused by self-generated movements (reafference) and external passive stimulation (exafference) differ in various brain regions. The ability to differentiate such sensory information can lead to movement execution with better accuracy. However, how sensory responses are adjusted in regard to this distinguishability during motor learning is still poorly understood. The cerebellum has been hypothesized to analyze the functional significance of sensory information during motor learning, and is thought to be a key region of reafference computation in the vestibular system. In this study, we investigated Purkinje cell (PC) spike trains as cerebellar cortical output when rats learned to balance on a suspended dowel. Rats progressively reduced the amplitude of body swing and made fewer foot slips during a 5-min balancing task. Both PC simple (SSs; 17 of 26) and complex spikes (CSs; 7 of 12) were found to code initially on the angle of the heads with respect to a fixed reference. Using periods with comparable degrees of movement, we found that such SS coding of information in most PCs (10 of 17) decreased rapidly during balance learning. In response to unexpected perturbations and under anesthesia, SS coding capability of these PCs recovered. By plotting SS and CS firing frequencies over 15-s time windows in double-logarithmic plots, a negative correlation between SS and CS was found in awake, but not anesthetized, rats. PCs with prominent SS coding attenuation during motor learning showed weaker SS-CS correlation. Hence, we demonstrate that neural plasticity for filtering out sensory reafference from active motion occurs in the cerebellar cortex in rats during balance learning. SS-CS interaction may contribute to this rapid plasticity as a form of receptive field plasticity in the cerebellar cortex between two receptive maps of sensory inputs from the external world and of efference copies from the will center for volitional movements.

Collateral projections from vestibular nuclear and inferior olivary neurons to lobules I/II and IX/X of the rat cerebellar vermis: a double retrograde labeling study

Axon collateral projections to various lobules of the cerebellar cortex are thought to contribute to the coordination of neuronal activities among different parts of the cerebellum. Even though lobules I/II and IX/X of the cerebellar vermis are located at the opposite poles in the anterior-posterior axis, they have been shown to receive dense vestibular mossy fiber projections. For climbing fibers, there is also a mirror-image-like organisation in their axonal collaterals between the anterior and posterior cerebellar cortex. However, the detailed organisation of mossy and climbing fiber collateral afferents to lobules I/II and IX/X is still unclear. Here, we carried out a double-labeling study with two retrograde tracers (FluoroGold and MicroRuby) in lobules I/II and IX/X. We examined labeled cells in the vestibular nuclei and inferior olive. We found a low percentage of double-labeled neurons in the vestibular nuclei (2.1 ± 0.9% of tracer-labeled neurons in this brain region), and a higher percentage of double-labeled neurons in the inferior olive (6.5 ± 1.9%), especially in its four small nuclei (18.5 ± 8.0%; including the β nucleus, dorsal cap of Kooy, ventrolateral outgrowth, and dorsomedial cell column), which are relevant for vestibular function. These results provide strong anatomical evidence for coordinated information processing in lobules I/II and IX/X for vestibular control.

Salivary proteomics in bisphosphonate-related osteonecrosis of the jaw

OBJECTIVE

The objective of this study was to identify differentially expressed salivary proteins in bisphosphonate-related osteonecrosis of the jaw (BRONJ) patients that could serve as biomarkers for BRONJ diagnosis.

SUBJECTS AND METHODS

Whole saliva obtained from 20 BRONJ patients and 20 controls were pooled within groups. The samples were analyzed using iTRAQ-labeled two-dimensional liquid chromatography-tandem mass spectrometry.

RESULTS

Overall, 1340 proteins were identified. Of these, biomarker candidates were selected based on P-value (<0.001), changes in protein expression (≥1.5-fold increase or decrease), and unique peptides identified (≥2). Three comparisons made between BRONJ and control patients identified 200 proteins to be differentially expressed in BRONJ patients. A majority of these proteins were predicted to have a role in drug metabolism and immunological and dermatological diseases. Of all the differentially expressed proteins, we selected metalloproteinase-9 and desmoplakin for further validation. Immunoassays confirmed increased expression of metalloproteinase-9 in individual saliva (P = 0.048) and serum samples (P = 0.05) of BRONJ patients. Desmoplakin was undetectable in saliva. However, desmoplakin levels tended to be lower in BRONJ serum than controls (P = 0.157).

CONCLUSIONS

Multiple pathological reactions are involved in BRONJ development. One or more proteins identified by this study may prove to be useful biomarkers for BRONJ diagnosis. The role of metalloproteinase-9 and desmoplakin in BRONJ requires further investigation.

High-voltage thin-film GaN LEDs fabricated on ceramic substrates: the alleviated droop effect at 670 W/cm(2)

High-voltage thin-film GaN LEDs with the emission wavelength of 455 nm were fabricated on ceramic substrates (230 W/m · K). The high-voltage operation was achieved by three cascaded sub-LEDs with dielectric passivation and metal bridges conformally deposited on the side walls. Under the driving power of 670 W/cm(2), the high-voltage LEDs exhibit much alleviated efficiency droop and the operative temperature below 80 °C. The excellent performances were attributed to the improved current spreading within each sub-LED and the superior heat sinking of the ceramic substrate.

Effects of spike sorting error on the Granger causality index

Accurately sorting individual neurons is a technical challenge and plays an important role in identifying information flow among neurons. Spike sorting errors are almost unavoidable and can roughly be divided into two types: false positives (FPs) and false negatives (FNs). This study investigates how FPs and FNs affect results of the Granger causality (GC) analysis, a powerful method for detecting causal interactions between time series signals. We derived an explicit formula based on a first order vector autoregressive model to analytically study the effects of FPs and FNs. The proposed formula was able to reveal the intrinsic properties of the GC, and was verified by simulation studies. The effects of FPs and FNs were further evaluated using real experimental data from the ventroposterior medial nucleus of the thalamus. Some practical suggestions for spike sorting are also provided in this paper.

Temporal and spatial temperature distribution in the glabrous skin of rats induced by short-pulse CO2 laser

Pain is a natural alarm that aids the body in avoiding potential danger and can also present as an important indicator in clinics. Infrared laser-evoked potentials can be used as an objective index to evaluate nociception. In animal studies, a short-pulse laser is crucial because it completes the stimulation before escape behavior. The objective of the present study was to obtain the temporal and spatial temperature distributions in the skin caused by the irradiation of a short-pulse laser. A fast speed infrared camera was used to measure the surface temperature caused by a CO2 laser of different durations (25 and 35 ms) and power. The measured results were subsequently implemented with a three-layer finite element model to predict the subsurface temperature. We found that stratum corneum was crucial in the modeling of fast temperature response, and escape behaviors correlated with predictions of temperature at subsurface. Results indicated that the onset latency and duration of activated nociceptors must be carefully considered when interpreting physiological responses evoked by infrared irradiation.

Acute ethanol exposure increases firing and induces oscillations in cerebellar Golgi cells of freely moving rats

BACKGROUND

Alcohol is a widely abused substance and is responsible for significant morbidity and mortality worldwide. The precise mechanisms underlying ethanol (EtOH)'s actions in the central nervous system (CNS) remain elusive. In vitro studies suggest that GABAergic interneurons are important targets of EtOH action in the CNS. Although EtOH generally acts to inhibit CNS neurons, it appears to cause an increase in GABAergic interneuron excitability. However, it has yet to be demonstrated that EtOH produces this effect in the brain of behaving animals. Here, we demonstrate for the first time that acute EtOH exposure excites a subtype of GABAergic interneuron (cerebellar Golgi cell [GoC]) in a freely moving animal.

METHODS

Electrophysiological recordings were made from microwire arrays implanted in the anterior cerebellum of freely moving rats.

RESULTS

Cerebellar GoCs display a slow, irregular, spontaneous action potential firing pattern under control conditions. EtOH caused dramatic and consistent increases in the rate and regularity of GoC discharges, including a redistribution of the power in the GoC spike train, such that power became concentrated in the 26.7 ± 7.3 Hz region.

CONCLUSIONS

Taken together with our previous findings, these data suggest that a major mechanism of EtOH actions on cerebellar function is an EtOH-induced de-afferentation at the input stage of the cerebellar cortex in the form of granule cell inhibition, and that this inhibition is caused by an increase in GoC firing. It is likely that GoCs may play a significant role both in the gating of information transmission to granule cells and in the modulation of the overall excitability of the cerebellum by tonically controlling granule cell activity.

Frequency ranges of heart rate variability related to autonomic nerve activity in the mouse

Mice have gained more and more attention in recent years and been widely used in transgenic experiments. Although the number of researches on the heart rate variability (HRV) of mice has been gradually increasing, a consensus on the frequency ranges of autonomic modulation has not been established. Therefore, the main purpose of this study was to find a HRV "prototype" for conscious mice in the state of being motionless and breathing regularly (called "genuinely resting"), and to determine the frequency ranges corresponding to the autonomic modulation. Further, whether these frequencies will change when the mice move freely was studied to evaluate the feasibility of the HRV spectrum as an index of the autonomic modulation of mice. The recording sites were specially arranged to simultaneously obtain the electrocardiography and electromyography data to be provided for the use of HRV analysis and motion monitoring, respectively. The states of being motionless and breathing regularly as judged from the electromyography results were selected as a genuine resting state of a conscious mouse. The frequencies related to autonomic modulation of HRV were determined by comparing the spectrum changes before and after blockades of the autonomic tone by different pharmaceutical agents in both the genuine resting state and freely moving states. Our results showed that the HRV of mice is not suitable for indexing sympathetic modulation; however, it is possible to use the spectral power in the frequency range between 0.1 and 1 Hz as an index of parasympathetic modulation.

An infrared range camera-based approach for three-dimensional locomotion tracking and pose reconstruction in a rodent

We herein introduce an automated three-dimensional (3D) locomotion tracking and pose reconstruction system for rodents with superior robustness, rapidity, reliability, resolution, simplicity, and cost. An off-the-shelf composite infrared (IR) range camera was adopted to grab high-resolution depth images (640×480×2048 pixels at 20Hz) in our system for automated behavior analysis. For the inherent 3D structure of the depth images, we developed a compact algorithm to reconstruct the locomotion and body behavior with superior temporal and solid spatial resolution. Since the range camera operates in the IR spectrum, interference from the visible light spectrum did not affect the tracking performance. The accuracy of our system was 98.1±3.2%. We also validated the system, which yielded strong correlation with automated and manual tracking. Meanwhile, the system replicates a detailed dynamic rat model in virtual space, which demonstrates the movements of the extremities of the body and locomotion in detail on varied terrain.

Involvement of the Cav3.2 T-type calcium channel in thalamic neuron discharge patterns

Background

Mice that have defects in their low-threshold T-type calcium channel (T-channel) genes show altered pain behaviors. The changes in the ratio of nociceptive neurons and the burst firing property of reticular thalamic (RT) and ventroposterior (VP) neurons in Cav3.2 knockout (KO) mice were studied to test the involvement of thalamic T-channel and burst firing activity in pain function.

Results

Under pentobarbital or urethane anesthesia, the patterns of tonic and burst firings were recorded in functionally characterized RT and VPL neurons of Cav3.2 KO mice. Many RT neurons were nociceptive (64% under pentobarbital anesthesia and 50% under urethane anesthesia). Compared to their wild-type (WT) controls, fewer nociceptive RT neurons were found in Cav3.2 KO mice. Both nociceptive and tactile RT neurons showed fewer bursts in Cav3.2 KO mice. Within a burst, RT neurons of Cav3.2 KO mice had a lower spike frequency and less-prominent accelerando-decelerando change. In contrast, VP neurons of Cav3.2 KO mice showed a higher ratio of bursts and a higher discharge rate within a burst than those of the WT control. In addition, the long-lasting tonic firing episodes in RT neurons of the Cav3.2 KO had less stereotypic regularity than their counterparts in WT mice.

Conclusions

RT might be important in nociception of the mouse. In addition, we showed an important role of Cav3.2 subtype of T-channel in RT burst firing pattern. The decreased occurrence and slowing of the bursts in RT neurons might cause the increased VP bursts. These changes would be factors contributing to alternation of pain behavior in the Cav3.2 KO mice.

Striatal volume changes in a rat model of childhood attention-deficit/hyperactivity disorder

Attention-deficit/hyperactivity disorder (ADHD) is one of the most common childhood neuropsychiatric disorders. Based on neuroimaging studies, the striatum is reported to be abnormal in size, but it is still not clear how they change during developmental stages. Spontaneously hypertensive rats (SHRs) are the commonly used animal model for ADHD. We investigated volume differences of the striatum at various ages before puberty in SHRs versus a control strain, Wistar-Kyoto rats (WKYs). Volumes of the bilateral striatum were measured using micrographs of Nissl-stained serial sections in both strains of rats at the ages of 4, 5, 6, 7, 8, 9, and 10weeks (n=4, each strain at each age). The results demonstrated that the age of a significant striatal volume difference between SHRs and WKYs was 5weeks; however, there was no significant difference for the corresponding total brain volume at each matched age. It suggested that the timing for striatal abnormalities in ADHD occurs during an early stage of childhood.

The correlation of mean sympathetic activity with low-frequency blood pressure and sympathetic variability

The low-frequency (0.2-0.8 Hz) component of blood pressure (BP) variability (LF(BP)) is used as an index of the low-frequency variability of sympathetic nerve activity (SNA) (LF(SNA)) in rats. It is unclear whether the LF(BP) can be used as an index of the mean SNA (mSNA). We investigated the correlation of the LF(BP) with different levels of the mSNA in this study to evaluate if it is a feasible tool for detecting differences in mSNA under physiological conditions. Correlation of the LF(SNA) with different mSNA levels was also investigated. The BP and renal SNA of rats were recorded in a nonanesthetized state. Values of the mSNA obtained from 531 recording epochs in six rats were graded into 30 levels with a bin resolution of 0.05 normalized units. A linear regression analysis showed that the correlation between the mSNA and LF(SNA) was higher than that between the mSNA and LF(BP). The mSNA was well correlated with the LF(SNA) over a wider mSNA range, while it was correlated with the LF(BP) only in a restricted range. These results demonstrated a restricted condition under which measuring the LF(BP) can be a definitive index of the mSNA, and further suggest the possibility of using the weighted LF(BP) as an index of the mSNA via intermediation by the LF(SNA) for a wider mSNA range.

Intravenous paclitaxel against metastasis of human gastric tumors of diffuse type

PURPOSE

Gastric cancer is one of the leading cancerous diseases worldwide. It is diagnosed often at the advanced stage for which chemotherapy is the main treatment option. The prognosis remains poor for metastatic, especially the diffuse type, gastric cancers. We investigated the efficacy of intravenously administered paclitaxel treating metastases of locally disseminated gastric tumors of diffuse type.

METHODS

Transfection of green fluorescent proteins (GFP)-expressing plasmid into human gastric cancer MKN45 cells of diffuse type was performed, and MKN45-GFP cells constitutively expressing GFP were isolated. The MKN45-GFP cells were orthotopically inoculated into the mouse peritoneal cavity, and tumor growth and organ metastases were monitored. Liver metastases were harvested, re-inoculated, monitored for liver metastases again, and harvested for further inoculation. This in vivo selection procedure was repeated to isolate a subline with high metastatic abilities demonstrated by in vitro invasion abilities using Transwell((R)) system. By visualizing the GFP-expressing tumors, the effects of intravenously administered paclitaxel against the growing peritoneally disseminated and metastasized tumors in nude mice without laparotomy were measured.

RESULTS

An in vivo selected gastric cancer cell line MKN45-GFP-ip4 with high metastatic ability was established. Its invasion ability was inhibited by paclitaxel treatments in vitro. The growths of metastatic and intraperitoneally disseminated MKN45-GFP-ip4 tumors were significantly suppressed by intravenous paclitaxel treatments in nude mice.

CONCLUSIONS

We found that intravenous paclitaxel is active against the metastases of human gastric cancer of peritoneal diffuse type, which warrants further investigations on optimizing the perioperative regimens with intravenous paclitaxel therapy for gastric cancer in patients.

Correlation of discharges of rostral ventrolateral medullary neurons with the low-frequency sympathetic rhythm in rats

The rostral ventrolateral medulla (RVLM) is critically important in the generation of sympathetic activity. The purpose of this study was to investigate whether discharges of RVLM neurons contribute to low-frequency (LF) sympathetic rhythms. Blood pressure (BP), renal sympathetic nerve activity (SNA), and neuronal activity in the RVLM were simultaneously recorded in seven anesthetized, paralyzed, and artificially ventilated rats. Fifty-one RVLM neurons were recorded and classified into three differential functional groups according to their activities related to baroreceptor input. Those in the category of spike firing inhibited by a BP increase (BP(I)) and which excited sympathetic discharges was the most abundant (24%). Coherence analysis was used to examine the relationship of the firing frequency of RVLM neurons with the LF (0.2-0.8Hz) rhythm of SNA. Forty-one percent of RVLM neurons showed a significant correlation to LF rhythms, and BP(I) neurons with sympathoexcitatory properties were the major contributors. In another 4 baroreceptor-denervated rats, 36 RVLM neurons were recorded. In these rats, RVLM neuronal activities no longer changed with BP fluctuations. Nevertheless, more than 40% of RVLM neurons were sympathoexcitatory, and 36% of RVLM neurons were still correlated with the LF SNA rhythm. Our results suggest that there are RVLM neurons involved in generating the LF rhythm in SNA and that the baroreflex can induce the participation of more neurons in LF rhythm generation.

Spike sorting by a minimax reduced feature set based on finite differences

Spikes are classified according to their finite differences in various orders. The fundamental idea that makes it work is that finite differences can extract and isolate features from spikes. This method showed better sorting quality and involved less labor than the methods of principal component analysis, original reduced feature set, and wavelet-based spike classifiers.

Frequency response characteristic of sympathetic mediated low-frequency blood pressure fluctuations in conscious rats

A quantitative relationship between power densities of blood pressure (PBP) and sympathetic nerve activity (PSNA) in a low-frequency range (LF, 0.016-0.85 Hz), expressed as PSNA=PBPxax10bx(frequency) was proposed in pentobarbital-anesthetized rats. For evaluating the general applicability of this equation, the quantitative relationship of power density ratio Hf=PBP/PSNA across frequency was tested in a conscious state. Wistar rats were chronically instrumented with a femoral artery catheter and recording electrode around the renal sympathetic nerve. The blood pressure and renal sympathetic nerve activity were monitored both under pentobarbital anesthesia and in a conscious state. Linear regression analysis of the relationship between the frequency and logarithmic magnitude of the power density ratio in the LF range revealed excellent fit in both conditions (r=-0.96+/-0.01 and -0.93+/-0.01 for anesthetized and conscious rats, respectively). Comparing the regression lines, rats under pentobarbital anesthesia had significantly larger values for the y-intercept and slope compared to rats in a conscious state (y-intercepts: 0.80+/-0.09>0.53+/-0.08; slopes: -2.86+/-0.26>-1.62+/-0.21). Our results demonstrate that it is also feasible to use the weighted PBP in LF as a quantitative index of sympathetic variability in conscious rats, but the evaluation of possible complications controlling the regression parameters is called for.

Differential morphine effects on short- and long-latency laser-evoked cortical responses in the rat

Evoked potential and ensemble neuronal activities were used to study the responses of the primary sensorimotor cortex (SmI) to noxious CO(2) laser irradiation of the middle part of the tail in conscious behaving rats. The hypothesis that systemic morphine treatment preferentially attenuates the longer-latency laser-evoked cortical responses was also tested. Laser-evoked potentials (LEPs) and multiple single-unit (SU) activities were, respectively, recorded from chronically implanted stainless-steel screws and microwire electrodes. When examined individually, many SmI neurons showed either short-latency (<100 ms) or long-latency (300-500 ms) responses to laser irradiation. These neurons are widely dispersed in the tail region and hind limb region of the SmI, and also in the forelimb and head regions of the primary motor cortex (MI). Quantitatively, a higher percentage of neurons in the SmI tail region responded with shorter latencies compared to those in the SmI hind limb region or in the MI. When responses of many simultaneously recorded SU were examined together, short-latency and long-latency SmI ensemble activities matched the LEP1 and LEP2, respectively. Systemic morphine significantly attenuated the long-latency but not the short-latency component in both LEPs as well as ensemble neuronal activity in the tail region of the SmI. These effects were blocked by naloxone pretreatment.

Wavelet-based analysis of low-frequency fluctuations of blood pressure and sympathetic nerve activity in rats

Biorthogonal wavelets were employed to quantify the relationship of fluctuations between blood pressure (BP) and sympathetic nerve activity (SNA). We forced the SNA to fluctuate by electrical stimulation the medulla in anesthetized, paralyzed, vagotomized, cardiac sympathetic-blocked, baroreceptor-denervated, and angiotensin II-converting enzyme-inhibited rats. Although spectral analysis showed a close coupling between fluctuations of BP and SNA at the stimulating frequencies, only the fluctuations of SNA in frequencies of 0.25 to approximately 0.4 Hz were proportional to BP fluctuations over the course of time. The results suggest that fluctuations transmitted from SNA to BP were uniform without shifting due to the nature of vasculature or the lagging of sympathetic action in frequencies of 0.25 to approximately 0.4 Hz, and support the possibility of using low-frequency variabilities of BP to quantitatively estimate fluctuations of SNA at time domain.

A simple method for fabricating horizontal and vertical microwire arrays

Microwire array electrodes are important in multi-site, multiple single-unit recording experiments. A simple method is described herein for the construction of microwire arrays consisting of evenly spaced insulated microwires in either horizontal or vertical orientations. Several key steps in the fabrication of a good microwire array electrode are made easier with this method. These steps include (1) arranging microwires into a desirable configuration, (2) keeping track of microwire sequences, and (3) soldering microwires to closely packed slots. This method needs only general mechanical tools and is relatively simple even for inexperienced workers.

The differential effects of tamoxifen and ICI 182,780 on the reduction of Na+/K+ ATPase activity and spontaneous oscillations by 17beta-estradiol

A prolonged treatment with 17beta-estradiol reduces the frequency of spontaneous oscillations and the Na+/K+ ATPase activity in rat uteri. Acute inhibition of Na+/K+ ATPase activity by a Na+/K+ ATPase inhibitor, ouabain, decreases the frequency of oxytocin-induced oscillations in uteri. Therefore, the purpose of this study was to examine whether the prolonged inhibition of Na+/K+ ATPase activity by 17beta-estradiol was estrogen receptor (ER)-dependent. The uterine explants from ovariectomized rats were cultured in vitro as our experimental model to compare the effect of two antiestrogenic compounds (ICI 182,780 and tamoxifen) on the Na+/K+ ATPase activity and the frequency of spontaneous oscillations. ATPase assay and a standard muscle bath apparatus were to measure the activity and the contraction. When compared with the control, a 2-day treatment with 17beta-estradiol in vivo or in vitro decreased the activity and the frequency. ICI 182,780 lowered the activity but tamoxifen did not. ICI 182,780 did not decrease the frequency but tamoxifen did. Even the reversal effects of these antiestrogenic compounds on the reduced activity and the frequency by 17beta-estradiol were different. Tamoxifen elicited a greater reversal effect on the reduced activity but ICI 182,780 did not. In contrast, ICI 182,780 elicited a greater reversal effect on the reduced frequency but tamoxifen did not. Prolonged inhibition of Na+/K+ ATPase activity by K+-free solution suppressed the frequency with the elevation of basal tension. Addition of KCl at lower concentrations (0.3-1.2 mM) induced oscillatory contraction after reducing the basal tension. As our data suggest, the prolonged effect of 17beta-estradiol may decrease uterine the activity through ER dependent and independent pathways. The reduction of uterine Na+/K+ ATPase activity by estrogens may increase the basal tension after each oscillatory cycle, which, in part, contributes to the reduced frequency of spontaneous oscillations.

Clinical and electroencephalographic findings in early and late onset benign childhood epilepsy with occipital paroxysms

Twenty-six patients were studied who had the clinical and electroencephalographic features of benign childhood epilepsy with occipital paroxysms (BCEOP) as defined by the Commission of the International League Against Epilepsy (ILAE). Twelve patients were characterized as having early-onset benign childhood occipital seizures (EBOS) susceptible syndrome, as described by Panayiotopoulos, and 14 patients had late onset childhood idiopathic occipital seizures (LOS). Patients with symptomatic epilepsy and whose EEGs exhibited occipital spikes were excluded. The age of onset of the EBOS group ranged from 2.6 to 9.4 years (mean: 4.9+/-1.7 years), which was significantly younger than the LOS group (range: 4-12 years, mean:8.4+/-2.5 years). Both sexes were equally affected. The patients in the EBOS group had less frequent and longer seizures, ictal vomiting, more frequent deviation of the eyes, adversive seizures and more frequent nocturnal and secondary generalized seizures (P<0.05). By comparison, patients in the LOS group had a higher incidence of seizures, shorter duration of seizures and more frequent diurnal onset (P<0.01); also, although not statistically significant, the LOS group had more frequent visual hallucinations and headaches. The EEG topography in both groups showed at either side of occipital area typical paroxysms that were unilateral or bilaterally synchronous. Neither group had dipoles according to scalp voltage mapping. The clinical prognoses were favorable for both groups. To distinguish EBOS from LOS, detailed description of the age of onset, motor symptoms, visual symptoms, presence of eye deviation and diurnal or nocturnal occurrence are essential.

Effect of antenatal dexamethasone on the expression of endothelial nitric oxide synthase in the lungs of postnatal pups

Activities of endothelial nitric oxide synthase (eNOS) are developmentally regulated and its presence at birth may play a role in the transition of cardiopulmonary circulation. Antenatal dexamethasone (Dex) therapy accelerates fetal lung maturation. We speculate that Dex therapy may enhance pulmonary eNOS protein expression in the newborn. This article examines whether antenatal Dex therapy affected the expression of eNOS in the lungs of rat pups in the postnatal period. Time-dated pregnant Wistar rats were subjected to 2 doses of Dex (0.8 mg/kg, intramuscularly, daily) or equivalent volume of normal saline at the 18th and 19th gestational day and delivered naturally. The newborn pups were randomly assigned to 4 groups by age: days 1, 3, 5, and 7. After homogenization, abundance of eNOS protein in lungs was determined by Western blot analysis. There were 7 dams in each group. Mean body weights of the pups in the Dex group were lighter than those in the control at birth and remained stunted up to day 7 (5.68+/-0.47 g v 6.34+/-0.47 g, P <.01). However, there were no differences in wet lung weights and lung/body weight ratios between both groups in the study period. Abundance of eNOS protein expression decreased in both the control and Dex groups (P < .01). Pups that received antenatal Dex had 39% more in abundance of eNOS protein expression in lungs when compared to the control on day 1 (P < .05) but there were no differences between both groups from day 3 to 7. We conclude that antenatal Dex therapy enhances the abundance of eNOS protein expression in the lung at birth and could be a factor in improving respiratory functions in infants who received antenatal steroid therapy.

The spectrum of postinfectious encephalomyelitis

The medical records of 52 consecutive patients diagnosed with postinfectious encephalitis/encephalomyelitis during the period from 1980 to 1998, including 29 males and 23 females, were reviewed. These patients were divided into three groups according to their clinical and neurodiagnostic characteristics: (1) group I: postinfectious encephalitis, 38 patients; (2) group II: acute disseminated encephalomyelitis (ADEM), 13 patients; (3) group III: multiphasic disseminated encephalomyelitis (MDEM), one patient. Fever, headache/vomiting, seizure and disturbance of consciousness were common clinical features in all patients, while pictures of pyramidal, extrapyramidal, brainstem, and spinal cord lesions were more often found in the group II and group III patients than in the group I patients. Magnetic resonance imaging (MRI) revealed abnormal lesions in six (60%) of ten group I patients, but all group II (n=7) and group III (n=1) patients who received MRI study showed abnormal signals in various regions of the brain including the cerebral hemisphere, basal ganglia, brainstem and cerebellum. Patients with ADEM and MDEM had a longer clinical course and more neurological sequelae than group I patients. This study demonstrates the breadth of the clinical spectrum of postinfectious encephalomyelitis. Thorough clinical observations and appropriate neurodiagnostic studies such as MRI are crucial for the diagnosis.

The inhibitory effects of lead on steroidogenesis in MA-10 mouse Leydig tumor cells

Lead is an environmental and occupational pollutant. It has been reported that lead affects the male reproductive system in humans and animals. However, the cellular mechanism of the adverse effect of lead on Leydig cell steroidogenesis remains unknown. To clarify whether lead has a direct effect on Leydig cells and how lead affects Leydig cells, MA-10 cells, a mouse Leydig tumor cell line, were exploited in this study. Lead acetate significantly inhibited hCG- and dbcAMP-stimulated progesterone production in MA-10 cells at 2 h. Steroid production stimulated by hCG or dbcAMP were reduced by lead. The mechanism of lead in reducing MA-10 cell steroidogenesis was further investigated. The expression of Steroidogenic Acute Regulatory (StAR) protein and the activities of P450 side-chain cleavage (P450scc) and 3beta-hydroxysteroid dehydrogenase (3beta-HSD) enzymes were detected. Cells were treated with dbcAMP, 22R-hydroxycholesterol or pregnenolone alone or in combination with lead acetate ranging from 10(-8) to 10(-5) M for 2 h. The expression of StAR protein stimulated by dbcAMP was suppressed by lead at about 50%. Progesterone productions treated with 22R-hydroxycholesterol or pregnenolone were reduced 30-40% in lead-treated MA-10 cells. These data suggest that lead directly inhibited steroidogenesis by decreasing StAR protein expression and the activities of P450scc and 3beta-HSD enzymes with a dose-response trend in MA-10 cells. Moreover, cadmium, a calcium channel blocker, abolished inhibitory effect of lead on MA-10 cell steroid production. This indicates that lead might act on calcium channel to regulate MA-10 cell steroidogenesis.

Postinfectious encephalomyelitis: etiologic and diagnostic trends

Fifty cases of postinfectious encephalomyelitis admitted to our Pediatric Department during the period 1980 to 1997 were consecutively collected and reviewed. There were 28 males and 22 females. The age of onset ranged from 9 months to 14 years. The antecedent infections included measles (6 cases), rubella (5 cases), mumps (4 cases), chicken pox (4 cases), Epstein-Barr virus infection (11 cases), mycoplasma infection (6 cases), and unknown etiology (14 cases). The cessation of measles, rubella, and mumps as causes for encephalomyelitis in our patients corresponds with the introduction of a measles-mumps-rubella nationwide vaccination program in Taiwan commencing in 1992. The main clinical symptoms were fever, headache, and/or vomiting, seizure, and motor weakness. The presenting signs included altered consciousness, meningeal signs, cranial nerve palsy, brainstem signs, involuntary movement, and cerebellar signs. Computed tomography scans were abnormal for 14 (56%) of 25 patients studied, whereas magnetic resonance imaging (MRI) disclosed lesions in 14 (82%) of 17 patients, with abnormal signals in various parts of the cerebral hemisphere, as well as in the basal ganglion, diencephalon, midbrain, brain stem, and cerebellum. Of the three patients with negative MRI findings, an abnormal finding on somatosensory evoked potential was noted for one patient, and a focal decrease in tracer uptake on single photon emission computed tomography (SPECT) was found for the other two patients. This study demonstrates that the causative agents of postinfectious encephalomyelitis in Taiwan have changed from those of traditional exanthematous diseases to nonspecific respiratory infections and suggests that this may also be the case in other parts of the world. MRI remains the imaging method of choice, whereas other neurofunctional studies such as evoked potentials and SPECT are complementary for the diagnosis.

Epstein-Barr virus encephalitis in children

Fourteen children with Epstein-Barr virus (EBV) encephalitis admitted to our pediatric department during the period 1988 to 1998 were collected and reviewed to characterize the clinical, laboratory and neuroradiological findings. There were 7 boys and 7 girls. The age of onset ranged from 10 months to 14 years. Among them, 5 patients belonged to Alice in Wonderland syndrome, 5 were diagnosed as acute viral encephalitis, 1 presented with acute meningoencephalitis followed by cerebellitis, the remaining 3 cases attributed to acute disseminated encephalomyelitis. The main symptoms were fever (43%), seizure (36%), bizarre behavior (31%), headache (21%) and metamorphopsia (36%). The presenting signs included altered consciousness (50%), meningeal sign (14%), bulbar sign (14%), cerebellar sign (7%), and cranial nerve palsy (7%). Classic findings of infectious mononucleosis were obscure. The laboratory data showed the existence of atypical lymphocyte in only one case but positive serology for EBV infection in all patients. Pleocytosis was found in 3 (30%) of 10 patients examined. Eight (67%) of 12 patients had nonspecific electroencephalographic changes in the acute stage. Computed tomography (CT) scans were abnormal in 2 (40%) of 5 patients tested; while magnetic resonance image (MRI) disclosed lesions in 5 (56%) of 9 patients, with abnormal signals in various parts of the brain. Single photon emission computed tomography (SPECT) brain scan showed abnormal perfusion lesions in 3 (75%) of 4 patients studied. The results demonstrate the diversity of neurological manifestations of EBV encephalitis. EBV should be considered in any acute neurological illness of uncertain etiology in the pediatric population. While MRI remains the image of choice in EBV encephalitis, SPECT detects the abnormal perfusion more precisely in a substantial number of patients.

Preferential reduction of Na+/K+ ATPase alpha3 by 17beta-estradiol influences contraction frequency in rat uteri

One beta1 and two alpha (alpha1 and alpha3) isoforms of Na+/K+-ATPase exist in rat uteri. Previous immunocytochemistry studies have suggested that the alpha3 isoform may be involved in calcium regulation indirectly. Estrogens are known to both modulate Na+/K+-ATPase activities in non-uterine tissues and suppress spontaneous uterine contractions in rats. Thus the purpose of this study was to examine the correlation between estrogens-modulated uterine contraction and the expression of Na+/K+-ATPase alpha3 isoform in rats. After 1-, 2-, and 4- day treatments with 17beta-estradiol (E2, 5 microg/ml/kg, s.c., daily), the diameter of uterine horn was measured. The contraction force of uterine strips was measured by standard muscle bath apparatus. The protein abundance and enzyme activity of Na+/K+-ATPase in rat uteri were measured by Western blot analysis and ATPase assay, respectively. One day of E2 decreased both contraction frequency and alpha3-protein expression without the change in uterine diameter, enzyme activity or other isoforms. Two days of E2 reduced contraction frequency, the enzyme activity, as well as alpha3- and beta1- protein abundance but increased alpha1-protein and uterine diameter. Four days of E2 elicited similar effects as two days of E2, but did not affect alpha1-protein abundance. In conclusion, E2 elicits differential effects on isoform expression. After 1-day treatment with 17beta-estradiol, the decrease in the expression of alpha3 and beta1 without a change in Na+/K+-ATPase activity suggests that some isoform other than beta1 exist in rat uteri. The positive correlation between the reduction of alpha3-and the decrease of contraction frequency suggests the involvement of alpha3 isoform in uterine oscillation.

In vivo exposure to carbon disulfide increases the contraction frequency of pregnant rat uteri through an indirect pathway

Exposure to CS2, an organic solvent, is associated with an increased rate of abnormal labor or dysmenorrhea. Contraction of quiescent uteri during pregnancy can cause preterm labor. We wish to know the effects of in vivo and in vitro exposures to CS2 on uterine contractions of mid-gestation rats. After 10-d exposure to 300 or 600 mg/kg CS2, uteri of pregnant rats were measured for contractile responses to various stimuli, such as KCl, oxytocin, carbachol or A23187, a calcium ionophore, using standard muscle bath apparatus. CS2 treatment significantly increased the contractile response to KCl, carbachol, and A23187. The increase to A23187 was the greatest. In contrast, in vitro exposure to CS2 immediately suppressed carbachol-induced contraction but did not affect spontaneous and KCl-induced contractions. Results showed the pregnant uterus of the rat is susceptible to CS2. The influence of in vivo exposure to CS2 on uterine contraction was opposite to that in vitro. The increased response of CS2-treated uteri to A23187 suggests that in vivo exposure to CS2 may sensitize contraction machinery to calcium through indirect pathways.

Effects of Fructus schizandrae on cycloheximide-induced amnesia in rats

The effects of Fructus Schisandrae (Schizandra Chinensis, (FS) on cycloheximide (CXM)-induced amnesia by using a passive avoidance task were studied in rats. FS at 0.25 and 0.75 g/kg administered for 1 week significantly prolonged the CXM-shortened step-through latency (STL). Of the fractions (n-hexane, chloroform and water), only the water fraction at 25 mg/kg administered for 1 week prolonged the CXM-shortened STL. These results suggest that the water fraction is the main active fraction of FS.

Effects of Fructus schizandrae on cycloheximide-induced amnesia in rats

The effects of Fructus Schisandrae (Schizandra Chinensis, (FS) on cycloheximide (CXM)-induced amnesia by using a passive avoidance task were studied in rats. FS at 0.25 and 0.75 g/kg administered for 1 week significantly prolonged the CXM-shortened step-through latency (STL). Of the fractions (n-hexane, chloroform and water), only the water fraction at 25 mg/kg administered for 1 week prolonged the CXM-shortened STL. These results suggest that the water fraction is the main active fraction of FS.

Quantitative relationship between fluctuations of blood pressure and sympathetic nerve activity in pentobarbital anesthetized rats

Transfer function analysis was used to examine the coupling between the sympathetic nerve activity (SNA) and the blood pressure (BP) fluctuations. In pentobarbital anesthetized Wistar rats, linear regression of the relationship between frequency (X-axis) and the logarithmic transfer magnitude, i.e. log (BP power density/renal SNA power density) (Y-axis), in the low frequency range (0.016-0.85 Hz) revealed an excellent fit (r = 0.97-0.98). Comparing the regression lines, rats under large dose of pentobarbital anesthesia (40 mg/kg, i.v. single dose) had significantly smaller intercept and slope values compared to rats under small dose of pentobarbital anesthesia (12.5 mg/kg). When intercept and slope values were compared between intact and acutely sinoaortic denervated rats, no significant difference were found. The results suggest that sympathetic modulation of vasomotor tone may be a major factor in generating BP fluctuations between 0.016 and 0.85 Hz in rats. Furthermore, these results support the possibility of using low frequency spectral power of BP to quantitatively estimate the fluctuations of SNA for rats under pentobarbital anesthesia if anesthetic depth is controlled.

Effect of U-995, a potent shark cartilage-derived angiogenesis inhibitor, on anti-angiogenesis and anti-tumor activities

BACKGROUND

A potent angiogenesis inhibitor, U-995, has been purified from the cartilage of the blue shark (Prionace glauca). U-995 is composed of two single peptides with molecular mass of 10 and 14 kDa, respectively.

MATERIALS AND METHODS

U-995 was designed to study human umbilical vein endothelial cell (HUVEC) migration and proliferation in vitro and angiogenesis induced by TNF alpha in chicken chorioallantoic membrane (CAM). Furthermore, we determined the ability of U-995 to inhibiting tumor cell growth and metastasis.

RESULTS

U-995 (15 and 30 micrograms/ml) markedly inhibited HUVEC migration and, at 15-50 micrograms/ml produced a dose-dependent decline in [3H]-thymidine incorporation. 30 and 50 micrograms/ml of U-995, when added to TNF alpha-induced angiogenesis caused discontinuous and disrupted blood vessels. Moreover, U-995 (30 micrograms/ml) markedly prevented collagenase-induced collagenolysis. In addition, when 200 micrograms U-995 was injected i.p. into mice it suppressed sarcoma-180 cell growth and B16-F10 mouse melanoma cell metastasis in vivo.

CONCLUSIONS

These results suggest that the anti-angiogenic effects of U-995 may be be due to interference with the proliferation and migration of HUVECs as well as inhibition of collagenolysis, thereby leading to inhibition of both angiogenesis and tumor cell growth.

Acute inhibition of spontaneous uterine contractions by an estrogenic polychlorinated biphenyl is associated with disruption of gap junctional communication

An estrogenic polychlorinated biphenyl, 4-hydroxy-2',4', 6'-trichlorobiphenyl (4-OH-TCB), inhibits oscillatory uterine contractions immediately. Because increased gap junction formation is associated with the development of synchronized uterine contractions at term, we examined whether the inhibitory effect of 4-OH-TCB on spontaneous oscillatory contractions was due to the disruption of gap junctional communication. The effect of 4-OH-TCB on gap junctional communication was determined by intercellular Lucifer yellow dye transfer in primary cultures of myometrial myocytes isolated from midgestation rats. Intercellular dye transfer was inhibited by 4-OH-TCB or 17beta-estradiol in a concentration-dependent manner. The inhibitory effect of 4-OH-TCB on intercellular dye transfer was reversed by tetraethylammonium (TEA). To examine effects on uterine contraction, longitudinal uterine strips were excised from midgestation rats and placed in muscle baths for isometric force measurement. Spontaneous uterine oscillation was suppressed by 4-OH-TCB or 17beta-estradiol. The inhibitory effects of 4-OH-TCB and 17beta-estradiol on spontaneous oscillations were counteracted by TEA but were not affected by a calcium ionophore (A23187) or a calcium-dependent potassium channel blocker (apamin). These results suggest that the acute inhibition of spontaneous oscillatory contractions by an estrogenic polychlorinated biphenyl may result from the disruption of intercellular communication.

Attenuation of cardiac but not vascular component in baroreflex of spontaneously hypertensive rats

The cardiac and vascular components of the baroreceptor reflex in spontaneously hypertensive rat (SHR) and stroke-prone spontaneously hypertensive rat (SHRSP) were compared against their counterparts in normotensive Wistar Kyoto rat (WKY). SHR, SHRSP and WKY of 12-16 weeks old were chronically instrumented for intra-arterial recording of blood pressure. Intravenous injections of phenylephrine and nitroprusside were used to challenge their baroreflex. The products of blood pressure change and the half time required for the pressure to return to the control value were used as the quantitative estimation of the blood pressure stabilizing capability. The cardiac component of the baroreflex was obtained from the change in the blood pressure stabilizing capability after blockade of beta and muscarinic receptors by atenolol and atropine, respectively. The vascular component was obtained by subtracting the cardiac component from the total stabilizing capability which was the difference after blockade with a ganglionic transmission blocker, hexamethonium. We found the cardiac component of the baroreflex of the hypertensive rats was significantly less sensitive than that of the WKY. In contrast, the vascular component of the baroreflex of the three strains did not differ significantly. Therefore, we concluded that the 12-16 week old SHRs were able to maintain a stable blood pressure due to the intact vascular component of the baroreflex.

Evidence of independent origin of multiple tumors from patients with prostate cancer

BACKGROUND

In men with prostate cancer, the gland usually contains two or more widely separate tumors. A critical issue of prostatic carcinogenesis is whether these multiple tumors are independent in origin. Molecular analysis of microsatellite (i.e., highly repeated, short nucleotide sequences) alterations in the DNA from separate tumors in the same prostate can be used to determine whether or not these separate tumors arise independently.

METHODS

Four microsatellite polymorphic markers (D8S133, D8S136, and D8S137, for a putative tumor suppressor gene on chromosome 8p, and D17S855, for the BRCA1 gene on chromosome 17q) were used to examine the pattern of allelic loss in prostate cancer from 19 patients who had two or more distantly separate tumors (i.e., located on contralateral sides or separated by at least half the anterior-posterior diameter of the prostate). Forty distantly separate tumors were microdissected, DNA samples were prepared from formalin-fixed, paraffin-embedded wholemount prostate tissue section, and the overall frequencies of loss of heterozygosity at the four loci were determined.

RESULTS

The pattern of allelic loss was compatible with independent tumor origin in 15 of 18 informative cases. A random discordant pattern of allelic deletion was observed in distantly separate tumors, whereas the same allele was consistently lost in cells from different regions of the same tumor. For three patients, the results were compatible with either intraglandular dissemination or independent origin of prostate cancer.

CONCLUSIONS

Our data suggest that multiple tumors in some patients with prostate cancer have independent origin.

Topographic mapping and clinical analysis of benign childhood epilepsy with centrotemporal spikes

We studied the topographic mapping of the electroencephalography (EEG) of 47 children whose clinical history and course were compatible with typical benign childhood epilepsy with centrotemporal spikes (BCECT). Twenty-nine (62%) patients showed typical dipole fields, with a negative potential field in the centrotemporal region and a positive field in the frontal region. Eighteen children did not demonstrate the typical dipole field. Their non-dipole rolandic discharges were localized in small fields of centrotemporal region. The patients with dipole fields in BCECT had significantly less frequent seizures than patients without dipole fields. Twelve of the 47 patients with BCECT (26%) had more than one EEG focus. The clinical courses of patients with multiple foci were not worse than those of patients with a single focus. We conclude that EEG topographic mapping is helpful in identifying typical or atypical EEG topographic patterns in patients with clinically diagnosed BCECT. We also conclude that the presence of dipole field usually indicates a better clinical course of epilepsy and multiple foci do not mean a poor clinical course.