Carbachol increases locus coeruleus activation by targeting noradrenergic neurons, inhibitory interneurons and inhibitory synaptic transmission

The locus coeruleus (LC) consists of noradrenergic (NA) neurons and plays an important role in controlling behaviours. Although much of the knowledge regarding LC functions comes from studying behavioural outcomes upon administration of muscarinic acetylcholine receptor (mAChR) agonists into the nucleus, the exact mechanisms remain unclear. Here, we report that the application of carbachol (CCh), an mAChR agonist, increased the spontaneous action potentials (sAPs) of both LC-NA neurons and local inhibitory interneurons (LC I-INs) in acute brain slices by activating M1/M3 mAChRs (m_1/3 AChRs). Optogenetic activation of LC I-INs evoked inhibitory postsynaptic currents (IPSCs) in LC-NA neurons that were mediated by γ-aminobutyric acid type A (GABA_A ) and glycine receptors, and CCh application decreased the IPSC amplitude through a presynaptic mechanism by activating M4 mAChRs (m₄ AChRs). LC-NA neurons also exhibited spontaneous phasic-like activity (sPLA); CCh application increased the incidence of this activity. This effect of CCh application was not observed with blockade of GABA_A and glycine receptors, suggesting that the sPLA enhancement occurred likely because of the decreased synaptic transmission of LC I-INs onto LC-NA neurons by the m₄ AChR activation and/or increased spiking rate of LC I-INs by the m_1/3 AChR activation, which could lead to fatigue of the synaptic transmission. In conclusion, we report that CCh application, while inhibiting their synaptic transmission, increases sAP rates of LC-NA neurons and LC I-INs. Collectively, these effects provide insight into the cellular mechanisms underlying the behaviour modulations following the administration of muscarinic receptor agonists into the LC reported by the previous studies.

Observation of a Strongly Isospin-Mixed Doublet in ^{26}Si via β-Delayed Two-Proton Decay of ^{26}P

β decay of proton-rich nuclei plays an important role in exploring isospin mixing. The β decay of ^{26}P at the proton drip line is studied using double-sided silicon strip detectors operating in conjunction with high-purity germanium detectors. The T=2 isobaric analog state (IAS) at 13 055 keV and two new high-lying states at 13 380 and 11 912 keV in ^{26}Si are unambiguously identified through β-delayed two-proton emission (β2p). Angular correlations of two protons emitted from ^{26}Si excited states populated by ^{26}P β decay are measured, which suggests that the two protons are emitted mainly sequentially. We report the first observation of a strongly isospin-mixed doublet that deexcites mainly via two-proton decay. The isospin mixing matrix element between the ^{26}Si IAS and the nearby 13 380-keV state is determined to be 130(21) keV, and this result represents the strongest mixing, highest excitation energy, and largest level spacing of a doublet ever observed in β-decay experiments.

Smartphone-Based Artificial Intelligence-Assisted Prediction for Eyelid Measurements: Algorithm Development and Observational Validation Study

BACKGROUND

Margin reflex distance 1 (MRD1), margin reflex distance 2 (MRD2), and levator muscle function (LF) are crucial metrics for ptosis evaluation and management. However, manual measurements of MRD1, MRD2, and LF are time-consuming, subjective, and prone to human error. Smartphone-based artificial intelligence (AI) image processing is a potential solution to overcome these limitations.

OBJECTIVE

We propose the first smartphone-based AI-assisted image processing algorithm for MRD1, MRD2, and LF measurements.

METHODS

This observational study included 822 eyes of 411 volunteers aged over 18 years from August 1, 2020, to April 30, 2021. Six orbital photographs (bilateral primary gaze, up-gaze, and down-gaze) were taken using a smartphone (iPhone 11 Pro Max). The gold-standard measurements and normalized eye photographs were obtained from these orbital photographs and compiled using AI-assisted software to create MRD1, MRD2, and LF models.

RESULTS

The Pearson correlation coefficients between the gold-standard measurements and the predicted values obtained with the MRD1 and MRD2 models were excellent (r=0.91 and 0.88, respectively) and that obtained with the LF model was good (r=0.73). The intraclass correlation coefficient demonstrated excellent agreement between the gold-standard measurements and the values predicted by the MRD1 and MRD2 models (0.90 and 0.84, respectively), and substantial agreement with the LF model (0.69). The mean absolute errors were 0.35 mm, 0.37 mm, and 1.06 mm for the MRD1, MRD2, and LF models, respectively. The 95% limits of agreement were -0.94 to 0.94 mm for the MRD1 model, -0.92 to 1.03 mm for the MRD2 model, and -0.63 to 2.53 mm for the LF model.

CONCLUSIONS

We developed the first smartphone-based AI-assisted image processing algorithm for eyelid measurements. MRD1, MRD2, and LF measures can be taken in a quick, objective, and convenient manner. Furthermore, by using a smartphone, the examiner can check these measurements anywhere and at any time, which facilitates data collection.

New α-Emitting Isotope ^{214}U and Abnormal Enhancement of α-Particle Clustering in Lightest Uranium Isotopes

A new α-emitting isotope ^{214}U, produced by the fusion-evaporation reaction ^{182}W(^{36}Ar,4n)^{214}U, was identified by employing the gas-filled recoil separator SHANS and the recoil-α correlation technique. More precise α-decay properties of even-even nuclei ^{216,218}U were also measured in the reactions of ^{40}Ar, ^{40}Ca beams with ^{180,182,184}W targets. By combining the experimental data, improved α-decay reduced widths δ^{2} for the even-even Po-Pu nuclei in the vicinity of the magic neutron number N=126 are deduced. Their systematic trends are discussed in terms of the N_{p}N_{n} scheme in order to study the influence of proton-neutron interaction on α decay in this region of nuclei. It is strikingly found that the reduced widths of ^{214,216}U are significantly enhanced by a factor of two as compared with the N_{p}N_{n} systematics for the 84≤Z≤90 and N<126 even-even nuclei. The abnormal enhancement is interpreted by the strong monopole interaction between the valence protons and neutrons occupying the π1f_{7/2} and ν1f_{5/2} spin-orbit partner orbits, which is supported by the large-scale shell model calculation.

Large Isospin Asymmetry in ^{22}Si/^{22}O Mirror Gamow-Teller Transitions Reveals the Halo Structure of ^{22}Al

β-delayed one-proton emissions of ^{22}Si, the lightest nucleus with an isospin projection T_{z}=-3, are studied with a silicon array surrounded by high-purity germanium detectors. Properties of β-decay branches and the reduced transition probabilities for the transitions to the low-lying states of ^{22}Al are determined. Compared to the mirror β decay of ^{22}O, the largest value of mirror asymmetry in low-lying states by far, with δ=209(96), is found in the transition to the first 1^{+} excited state. Shell-model calculation with isospin-nonconserving forces, including the T=1, J=2, 3 interaction related to the s_{1/2} orbit that introduces explicitly the isospin-symmetry breaking force and describes the loosely bound nature of the wave functions of the s_{1/2} orbit, can reproduce the observed data well and consistently explain the observation that a large δ value occurs for the first but not for the second 1^{+} excited state of ^{22}Al. Our results, while supporting the proton-halo structure in ^{22}Al, might provide another means to identify halo nuclei.

Inhibitory interneurons regulate phasic activity of noradrenergic neurons in the mouse locus coeruleus and functional implications

KEY POINTS

The locus coeruleus (LC) contains noradrenergic (NA) neurons that respond to novel stimuli in the environment with phasic activation to initiate an orienting response; phasic LC activation is also triggered by stimuli, representing the outcome of task-related decision processes, to facilitate ensuing behaviours and help optimize task performance. Here, we report that LC-NA neurons exhibit bursts of action potentials in vitro resembling phasic LC activation in vivo, and the activity is gated by inhibitory interneurons (I-INs) located in the peri-LC. We also observe that inhibition of peri-LC I-INs enhances prepulse inhibition and axons from cortical areas that play important roles in evaluating the cost/reward of a stimulus synapse on both peri-LC I-INs and LC-NA neurons. The results help us understand the cellular mechanisms underlying the generation and regulation of phasic LC activation with a focus on the role of peri-LC I-INs.

ABSTRACT

Noradrenergic (NA) neurons in the locus coeruleus (LC) have global axonal projection to the brain. These neurons discharge action potentials phasically in response to either novel stimuli in the environment to initiate an orienting behaviour or stimuli representing the outcome of task-related decision processes to facilitate ensuing behaviours and help optimize task performance. Nevertheless, the cellular mechanisms underlying the generation and regulation of phasic LC activation remain unknown. We report here that LC-NA neurons recorded in brain slices exhibit bursts of action potentials that resembled the phasic activation-pause profile observed in animals. The activity was referred to as phasic-like activity (PLA) and was suppressed and enhanced by blocking excitatory and inhibitory synaptic transmissions, respectively. These results suggest the existence of a local circuit to drive PLA, and the activity could be regulated by the excitatory-inhibitory balance of the circuit. In support of this notion, we located a population of inhibitory interneurons (I-INs) in the medial part of the peri-LC that exerted feedforward inhibition of LC-NA neurons through GABAergic and glycinergic transmissions. Selective inhibition of peri-LC I-INs with chemogenetic methods could enhance PLA in brain slices and increase prepulse inhibition in animals. Moreover, axons from the orbitofrontal and prelimbic cortices, which play important roles in evaluating the cost/reward of a stimulus, synapse on both peri-LC I-INs and LC-NA neurons. These observations demonstrate functional roles of peri-LC I-INs in integrating inputs of the frontal cortex onto LC-NA neurons and gating the phasic LC output.

[Blocking effects of serum antibodies against HBGA binding to norovirus GII.4 of population in oyster culture area of Guangdong Province]

Objective: Evaluate GII.4 norovirus infection and blocking effects of serum antibodies against HBGAs binding to GII.4 norovirus of population in oyster culture area, provide references for screening of fully human monoclonal antibody. Methods: Using a random survey method to collect blood and saliva samples in oyster culture area, select serum samples from the inland region of Guangdong as control group. Identification of salivary HBGA receptor phenotype and detection of serum antibody levels between two areas by ELISA. A vitro neutralization model was to determine the efficiency of serum antibodies blocking GII.4 norovirus and HBGA receptors binding. Results: The age were (50.68 ± 15.17), (52.52 ± 15.90) and (51.37 ± 13.32) years old of 2015, 2016 in experimental group, and in control group, respectively. Males accounted for 5.9% (70/195), 36.6%(60/164), 40.8% (69/169) (χ(2)=0.93, P=0.334). The mean value of serum antibodies Absorbance value was 2.521±0.05 of 2015 and was 2.583±0.045 of 2016 in oyster culture area, the mean value was 2.249±0.05 in control group, there was a statistical difference among three group (F=13.28, P<0.001). The antibody prevalence in the three groups was 100%. BT50 geometric mean titer (GMT) of oyster culture area in 2015 was 423.1±40.11, culture group was 248.2±25.63, there was a statistical difference (t=3.73, P<0.001). Conclusion: The population in oyster culture area does have more chance of exposure and infection GII.4 norovirus, Serum antibody of blocking ability in oyster culture areas is better than the general population in inland city. Suggesting that the population is more immunity resistant infected GII.4 norovirus.

Does the addition of hyperbaric oxygen therapy to conventional treatment modalities influence the outcome of soldiers with idiopathic sudden sensorineural hearing loss?

BACKGROUND

Idiopathic sudden sensorineural hearing loss (ISSNHL) is defined as a 30-decibel (dB) loss in hearing over three contiguous frequencies within 3 days. The cause remains unknown, and there is currently no consensus in the literature as to how it is best treated. Conventional treatment in our unit comprises steroids, pentoxyphiline and dextran, with the potential addition of hyperbaric oxygen therapy (HBOT).

METHODS

A prospective randomised trial was performed on all soldiers diagnosed with ISSNHL in our institution from 1 January 2007 to 31 December 2016. Participants were randomly allocated to one of two groups. Group A was treated with conventional treatment plus HBOT. Group B was treated with conventional treatment only. Data collection included age, gender, clinical symptoms, pure-tone audiometry results and treatment outcome.

RESULTS

60 participants were enrolled (53 male, 7 female) with ages ranging from 18 to 65 years (mean age of 30.3). No significant differences were observed in the baseline characteristics between the two groups, including gender, age, site, associated symptoms, duration of symptoms and severity of hearing loss. Hearing recovery using Siegel's criteria on days 8 and 13 showed no significant differences between treatment groups. However, the hearing recovery on day 180 was significantly better in those who received the conventional treatment plus HBOT (P<0.05). Additionally, no significant side effects were observed in either group.

CONCLUSIONS

HBOT plus existing conventional treatment was associated with a better outcome than conventional treatment alone. We would recommend the addition of HBOT is recommended as a first-line treatment modality for all soldiers presenting with ISSNHL.

[Technical guideline for human rabies prevention and control (2016)]

In order to promote the prevention and control programs on rabies in our country, to regulate the prevention and disposition of rabies and to reduce the deaths caused by rabies, the Chinese Center for Disease Control and Prevention has organized a panel of experts, in the reference with Guidelines issued by WHO, American Advisory Committee on Immunization Practices, and the latest research progress from home and abroad, and compiled this document-"Technical Guidelines for Human Rabies Prevention and Control (2016)". The Guidelines conducted a systematic review on the etiology, clinical characteristics, laboratory diagnosis, epidemiology of rabies and provided evidence on varieties, mechanisms, effects, side-effects and security of rabies vaccine, as well as on other preparations on passive immunity of its kind, on methods related to prevention and disposition of exposure etc, finally to have come up with the recommendation on the above mentioned various techniques. The guidelines will be used by staff working on prevention and control of rabies from the Center for Disease Control and Prevention at all levels, from the departments of outpatient and divisions of infection and emergency control in all the medical institutions. The guideline will be updated and revised, following the research progress from home and abroad.

GABAB receptor-mediated tonic inhibition regulates the spontaneous firing of locus coeruleus neurons in developing rats and in citalopram-treated rats

KEY POINTS

Noradrenaline (NA)-releasing neurons in the locus coeruleus (LC) provide NA to the forebrain and play important roles in regulating many brain functions. LC neurons are subject to tonic inhibition mediated by GABAB receptors (GABAB Rs) and that the extent of the effect varies with ambient GABA levels. GABAB R-mediated tonic inhibition can effectively tune the spontaneous firing rate (SFR) of LC neurons; it is developmentally regulated and is responsible for maintaining a constant SFR of LC neurons during development. In male, but not female rats, chronic perinatal treatment with citalopram, a selective serotonin reuptake inhibitor, results in downregulation of GABAB R-mediated tonic inhibition of LC neurons that partially accounts for increased SFR in male, but not female, rats receiving such treatment. Our results show that GABAB R-mediated tonic inhibition could be an important player in the development of normal and abnormal behaviours/brain functions associated with the LC-NA system. Noradrenaline (NA)-releasing neurons in the locus coeruleus (LC) provide NA to the forebrain. Their activity is believed to be a key factor regulating the wakefulness/arousal level of the brain. In this study, we found that the activity of NA-releasing neurons in the LC (LC neurons) was subject to γ-aminobutyric acid (GABA) tonic inhibition through GABAB receptors (GABAB Rs), but not GABAA receptors. The intensity of GABAB R tonic inhibition was found to depend on ambient GABA levels, as it was dramatically increased by blockade of GABA reuptake. It also varied with the function of GABAB Rs. The GABAB R activity on LC neurons was found to increase with postnatal age up to postnatal days 8-10, resulting in increased tonic inhibition. Interestingly, there was no significant difference in the spontaneous activity of LC neurons at different postnatal ages unless GABAB R tonic inhibition was blocked. These results show that, during postnatal development, there is a continuous increase in GABAB R tonic inhibition that maintains the activity of LC neurons at a proper level. In male, but not female, rats, chronic perinatal treatment with citalopram, a selective serotonin reuptake inhibitor, reduced GABAB R activity and tonic inhibition, which might result in the significantly higher spontaneous activity of LC neurons seen in these animals. In conclusion, our results show that GABAB R-mediated tonic inhibition has a direct impact on the spontaneous activity of LC neurons and that the extent of the effect varies with ambient GABA levels and functionality of GABAB R signalling.

Screening for Oral Cavity Cancer: A 1-year Experience of a Regional Hospital in Taiwan

INTRODUCTION

The purpose of this study was to analyze the risk factors affecting precancerous lesions, and cancer of oral cavity, and to assess efficacy of visual screening for oral mucosal lesions.

METHODS

The medical records of patients older than 30 years of age with history of habitual cigarette smoking or betel quid chewing that received screening for oral mucosal lesions between January 2012 and December 2012 were retrospectively reviewed. The patients' age, gender, risk factors, screening findings, and histopathology results of biopsy were included for further analysis.

RESULTS

A total of 1341 patients were enrolled in this study. There were 1080 males and 261 females ranging from 30 to 96 years of age, with a mean age of 53.9±13.6 years. After screening, 226 (16.9%) were found to be positive of oral lesions. Among these 226 patients, 69 (30.5%) underwent biopsy under local anesthesia, and the histopathology showed malignancy in 13 (5.8%). All of the confirmed malignant cases were squamous cell carcinoma. Among them, 12 received further staging examination and one was lost to follow-up resulting in unknown stage. The early stage oral cavity cancer (stage I and II) accounted for 84.6% (11/13).

CONCLUSIONS

The detection rate of early stage oral cavity cancer in our study was reasonable. Therefore, visual screening for oral cavity cancer is recommended for patients with habitual cigarette smoking or betel quid chewing.

A case of HIV-1 slow seroconversion: diagnostic implications

We report the case of a 30-year-old woman who failed to achieve diagnostic Western blot criteria for HIV-1 infection until 21 months after her initial presentation. This case highlights the importance of suspecting delayed HIV seroconversion in cases with persistently indeterminant Western blots.

The zona incerta modulates spontaneous spike-wave discharges in the rat

The contribution of the zona incerta (ZI) of the thalamus on spike-wave discharges (SWDs) was investigated. Chronic recordings of bilateral cortices, bilateral vibrissa muscle, and unilateral ZI were performed in Long-Evans rats to examine the functional role of SWDs. Rhythmic ZI activity appeared at the beginning of SWD and was accompanied by higher-oscillation frequencies and larger spike magnitudes. Bilateral lidocaine injections into the mystacial pads led to a decreased oscillation frequency of SWDs, but the phenomenon of ZI-related spike magnitude enhancement was preserved. Moreover, 800-Hz ZI microstimulation terminates most of the SWDs and whisker twitching (WT; >80%). In contrast, 200-Hz ZI microstimulation selectively stops WTs but not SWDs. Stimulation of the thalamic ventroposteriomedial nucleus showed no obvious effect on terminating SWDs. A unilateral ZI lesion resulted in a significant reduction of 7- to 12-Hz power of both the ipsilateral cortical and contralateral vibrissae muscle activities during SWDs. Intraincertal microinfusion of muscimol showed a significant inhibition on SWDs. Our present data suggest that the ZI actively modulates the SWD magnitude and WT behavior.

Laser-induced fluorescence of pyrene and other polycyclic aromatic hydrocarbons (PAH) in seawater

Polycyclic aromatic hydrocarbons (PAH) in the marine environment are currently of great concern due to their potential carcinogenicity. The standard methods of detection and quantification of PAH in seawater and sediments are costly, time-consuming and do not account for the heterogeneous nature of their distribution and sources. Laser-induced, time-resolved fluorescence spectroscopy may help to overcome these limitations. Several PAH have relatively long-lived stimulated fluorescence emissions, which allow them to be detected among a background of more intense but shorter-lived chromophores. Using time-delayed techniques we have shown an ability to detect PAH, principally pyrene, at environmental levels (ng l(-1)) both in the laboratory and in situ in Boston Harbor and other study areas. Further development may lead to the rapid determination of several PAH in typical near-shore marine environments.

Blood vessel epicardial substance (Bves) regulates epidermal tight junction integrity through atypical protein kinase C

Bves is widely observed in the cell junction of the skin, epicardium, intestine, and cornea of both developmental embryos and mature adults. However, it is not clear how Bves confers its role in intercellular adhesion. Here, we identified the zebrafish bves (zBves) and found that the epidermal barrier function could be disrupted after knockdown of Bves, and these zBves morphants were sensitive to osmotic stress. A loss of zBves would affect the partitioning defective protein (PAR) junctional complex identified by the rescue experiment with tjp-2/ZO-2 or the PAR complex (par-3, par-6, and prkci/atypical (a)PKC) mRNAs, in which the survival rate of embryos increased 11, 24, 25, and 28%, respectively, after injection with junctional components; the tjp-2 and aPKC mRNA-rescued embryos also had 24 and 45% decreases in the defective rate. Immunofluorescent studies demonstrated that the aggregation of aPKC around the cell junctions had disintegrated in zBves morphants. However, the expression and assembly of zBves were not influenced by aPKC-MO. These results indicate that a loss of zBves affects the proteins involved in the pathway of the PAR junctional complex, especially aPKC, and both aPKC and Bves are indispensable to claudin expression.

Protective effect of caffeic acid on paclitaxel induced anti-proliferation and apoptosis of lung cancer cells involves NF-κB pathway

Caffeic acid (CA), a natural phenolic compound, is abundant in medicinal plants. CA possesses multiple biological effects such as anti-bacterial and anti-cancer growth. CA was also reported to induce fore stomach and kidney tumors in a mouse model. Here we used two human lung cancer cell lines, A549 and H1299, to clarify the role of CA in cancer cell proliferation. The growth assay showed that CA moderately promoted the proliferation of the lung cancer cells. Furthermore, pre-treatment of CA rescues the proliferation inhibition induced by a sub-IC₅₀ dose of paclitaxel (PTX), an anticancer drug. Western blot showed that CA up-regulated the pro-survival proteins survivin and Bcl-2, the down-stream targets of NF-κB. This is consistent with the observation that CA induced nuclear translocation of NF-κB p65. Our study suggested that the pro-survival effect of CA on PTX-treated lung cancer cells is mediated through a NF-κB signaling pathway. This may provide mechanistic insights into the chemoresistance of cancer calls.

Mediation of vagal cardioinhibitory responses by glutamatergic receptors in the caudal medulla of turtles

Our previous studies showed that electrical stimulation of the nuclei ambiguous (NA) or dorsomotor nuclei of the vagus (DMV) complex in the brain stem of spontaneously breathing pond turtles (Cyclemys fiavomarginata), anesthetized with chloralose (4 mg/100 g) and urethane (40 mg/100 g), produced a marked slowing or even cessation of the heart rate, and resulted in an immediate fall of blood pressure. Results of the present study further demonstrated that the cardioinhibitory responses could also be elicited by microinjection of monosodium glutamate (0.2-20 nl, 50 mM) into the NA/DMV complex in turtles. A two-barrel glass micropipette held in a manipulator was connected to a pneumatic pressure pump for microinjection. The glutamate-induced cardioinhibitory responses could be significantly reduced in a dose-dependent manner by pretreatment with AP-5 (a NMDA receptor antagonist, at 1-8 nmole) or CNQX (a non-NMDA receptor antagonist; at 0.1-0.8 nmole) 20 min before glutamate administration. Histochemical verification by injecting horseradish peroxidase into the cervical vagus nerves revealed that retrogradely labeled glutamatergic neurons in the NA/DMV complex were observed. These results suggest that glutamatergic receptors in the caudal medulla may mediate vagal cardioinhibitory responses in the turtle.

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.

Distribution of large terminal inputs from the primary and secondary somatosensory cortices to the dorsal thalamus in the rodent

The present study was undertaken to determine the precise projection pattern from the primary (S1) and secondary (S2) somatosensory cortices to the posterior nuclear proper (POm) and ventroposterior thalamic nuclei (VP). The POm was previously shown to receive large boutons arising exclusively from layer V of the S1 barrel region. This descending input was proposed to play a key role, namely, as a driver, in shaping the receptive property of POm neurons. To determine whether other body parts and the S2 also contribute such unique inputs to the dorsal thalamus, anterograde neuroanatomical tracers were focally deposited in the S1 and S2 forepaw and whisker regions of rats and C57BL6-Tg (GFPm)/Thy1 transgenic mice. Our major findings were that, 1) irrespective of body representations, both the S1 and the S2 provided corticothalamic large terminals to the POm with comparable morphological characteristics and 2) descending large terminals were also noted in particular subzones within the VP, including boundary and caudal areas. We concluded, based on these findings, that the rodent VP has three partitions: the rostral VP innervated by small corticothalamic terminals, the caudal VP with both corticothalamic small and large terminals, and a surrounding shell region, which also contained large terminals. Furthermore, assuming that the large terminal has a driver's role, we propose that particular subzones in the VP may play a role as a multiple-order thalamic relay so that they can simultaneously coordinate with first- and higher-order relays in the thalamocortical circuitry for processing somatosensory information.

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.

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.

alpha-Phenyl-n-tert-butyl-nitrone attenuates lipopolysaccharide-induced brain injury and improves neurological reflexes and early sensorimotor behavioral performance in juvenile rats

Our previous study showed that treatment with alpha-phenyl-n-tert-butyl-nitrone (PBN) after exposure to lipopolysaccharide (LPS) reduced LPS-induced white matter injury in the neonatal rat brain. The object of the current study was to further examine whether PBN has long-lasting protective effects and ameliorates LPS-induced neurological dysfunction. Intracerebral (i.c.) injection of LPS (1 mg/kg) was performed in postnatal day (P) 5 Sprague Dawley rat pups and PBN (100 mg/kg) or saline was administered intraperitoneally 5 min after LPS injection. The control rats were injected (i.c.) with sterile saline. Neurobehavioral tests were carried out from P3 to P21, and brain injury was examined after these tests. LPS exposure resulted in severe brain damage, including enlargement of ventricles bilaterally, loss of mature oligodendrocytes, impaired myelination as indicated by the decrease in myelin basic protein immunostaining, and alterations in dendritic processes in the cortical gray matter of the parietal cortex. Electron microscopic examination showed that LPS exposure caused impaired myelination as indicated by the disintegrated myelin sheaths in the juvenile rat brain. LPS administration also significantly affected neurobehavioral functions such as performance in righting reflex, wire hanging maneuver, cliff avoidance, negative geotaxis, vibrissa-elicited forelimb-placing test, beam walking, and gait test. Treatment with PBN, a free radical scavenger and antioxidant, provided protection against LPS-induced brain injury and associated neurological dysfunction in juvenile rats, suggesting that antioxidation might be an effective approach for therapeutic treatment of neonatal brain injury induced by infection/inflammation.

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.

Neural and cardiac activities are altered by injection of picomoles of glutamate into the nucleus ambiguus of the rat

A quantitative evaluation of the thresholds of changes in the firing rate/pattern and depolarizing block of the neuron and the bradycardiac response by pressure microinjection of 10 mM glutamate (Glu) into the region of the nucleus ambiguus (NA) of the ventral medulla was performed in anesthetized rats. A change in neuronal activity was shown with injection of about 2 pmol of Glu. A depolarizing block of single-unit activity could be observed at 2.9 +/- 0.3 nl (approximately 30 pmol, n = 22). Maximal bradycardiac response (-50 +/- 5%) was elicited with 4.4 +/- 0.7 nl (approximately 50 pmol, n = 10), which is significantly smaller than the ranges used in previous studies. Based on these results, a safe and effective use of 10 mM Glu to induce neuronal or physiological response should be in the range of a few nanoliters and less than 100 pmol, especially for the NA.

Caffeine in Boston Harbor seawater

Caffeine has been detected in Boston Harbor seawater with concentrations ranging from 140 to 1600 ng l(-1), and in Massachusetts Bay seawater at concentrations from 5.2 to 71 ng l(-1). Sources of caffeine appear to be anthropogenic with higher concentrations in the seawater of Boston's inner harbor and in freshwater sources to the harbor. Charles River water and Deer Island sewage treatment plant effluent, the two major sources of freshwater to the harbor, contained 370 and 6700 ng l(-1) of caffeine, respectively, in 1998. Sewage influent and effluent concentrations appear to be consistent with consumption estimates of caffeinated beverages for the Boston area and total organic carbon removal targets for treated sewage. Caffeine was inversely correlated to salinity in a transect from the mouth of Boston Harbor to Stellwagen Basin, indicating it may be a useful chemical tracer of anthropogenic inputs to marine systems.

Extracorporeal shock wave promotes growth and differentiation of bone-marrow stromal cells towards osteoprogenitors associated with induction of TGF-beta1

Extracorporeal shock-wave (ESW) treatment has been shown to be effective in promoting the healing of fractures. We aimed to determine whether ESW could enhance the growth of bone-marrow osteoprogenitor cells. We applied ESW to the left femur of rats 10 mm above the knee at 0.16 mJ/mm2 in a range of between 250 and 2000 impulses. Bone-marrow cells were harvested after ESW for one day and subjected to assessment of colony-forming unit (CFU) granulocytes, monocytes, erythocytes, megakaryocytes (CFU-Mix), CFU-stromal cells (CFU-S) and CFU-osteoprogenitors (CFU-O). We found that the mean value for the CFU-O colonies after treatment with 500 impulses of ESW was 168.2 CFU-O/well (SEM 11.3) compared with 88.2 CFU-O/well (SEM 7.2) in the control group. By contrast, ESW treatment did not affect haematopoiesis as shown by the CFU-Mix (p = 0.557). Treatment with 250 and 500 impulses promoted CFU-O, but not CFU-Mix formations whereas treatment with more than 750 impulses had an inhibiting effect. Treatment with 500 impulses also enhanced the activity of bone alkaline phosphatase in the subculture of CFU-O (p<0.01), indicating a selective promotion of growth of osteoprogenitor cells. Similarly, formation of bone nodules in the long-term culture of bone-marrow osteoprogenitor cells was also significantly enhanced by ESW treatment with 500 impulses. The mean production of TGF-beta1 was 610 pg/ml (SEM 84.6) in culture supernatants from ESW-treated rats compared with 283 pg/ml (SEM 36.8) in the control group. Our findings suggest that optimal treatment with ESW could enhance rat bone-marrow stromal growth and differentiation towards osteoprogenitors presumably by induction of TGF-beta1.

Distribution and partitioning of polycyclic aromatic hydrocarbons (PAHs) in different size fractions in sediments from Boston Harbor, United States

The concentrations of 16 US EPA priority pollutant polycyclic aromatic hydrocarbons (PAHs) were analyzed in four size fractions (< 62, 62-125, 125-250, and > 250 microm) in three contaminated Boston Harbor sediments. Total PAH concentrations ranged from 7.3 to 358 microg/g dry wt. and varied largely among the different size fractions in these sediments. For all three sites, the highest PAH concentrations were associated with the large size (> 250 microm) fractions while the fine silt and clay fractions (< 62 microm) contained relatively low PAHs. Despite the great concentration differences, the composition of PAHs in the four size fractions of these sediments showed similar patterns dominated by PAHs with three or more rings. By examining the distribution patterns of selected alkyl homologs to parent compounds, the results indicate that the major PAHs contributing to the high contamination in the inner harbor sediments were from pyrogenic sources. A positive correlation between PAHs and sedimentary organic carbon exists for all size fractions in the sediments. Calculated organic carbon normalized partition coefficients (log K(oc)) for selected major PAHs indicate near-equilibrium partitioning of PAHs among the different size fractions despite their large concentration variations. Sedimentary organic matter associated with different size fractions was the controlling factor for the observed distribution differences of PAHs among the size fractions. Our results also suggest that sedimentary organic matter with different origins and maturities may have somewhat different PAH sorption characteristics. Particulate organic matter of charcoal, plant detritus and Capitella fecal pellets in the sediments appear to sorb PAHs more strongly than organic matter associated with clay minerals. The strong association of PAHs with these organic particles in sediments will have a great influence not only on their distribution but also on long-term environmental impact.

Physical shock wave mediates membrane hyperpolarization and Ras activation for osteogenesis in human bone marrow stromal cells

Physical shock wave (SW) has shown effectiveness on promotion of bone growth. We have recently demonstrated that SW could promote bone marrow stromal cell differentiation toward osteoprogenitor associated with induction of TGF-beta1. We have further demonstrated that SW-induced membrane hyperpolarization and Ras activation acted an early signal for the osteogenesis in human bone marrow stromal cells. An optimal dose of SW treatment at 0.16 mJ/mm(2) for 500 impulses induced a rapid membrane hyperpolarization in 5 min, activation of Ras in 30 min, and cell proliferation in 2 days. The SW-promoted cell growth was related to osteogenesis as demonstrated by increase of bone alkaline phosphatase activity in 6 days and osteocalcin mRNA expression in 12 days. In support that SW-induced Ras activation mediated osteogenesis of human bone marrow stromal cells, we further demonstrated that transfection of bone marrow stromal cells with a dominant negative Ras mutant (Asn-17 ras(H)) abrogated the SW enhancement of osteogenic transcription factor (CBFA1) activation, osteocalcin mRNA expression, and bone nodule formations. These results suggest that physical SW promotes bone marrow stromal cell differentiation toward osteogenic lineage via membrane hyperpolarization, followed by Ras activation and specific osteogenic transcription factor CBFA1 expression. A link between physical SW and biomembrane perturbation-mediated Ras activation may highlight how noninvasive physical agents could be used to promote fracture healing and to rescue patients with osteoporosis and osteopenic disorders in the future.

Dynamic changes of touch- and laser heat-evoked field potentials of primary somatosensory cortex in awake and pentobarbital-anesthetized rats

In this investigation, changes of mechanical- (MEP) and laser-evoked potentials (LEP) in rat primary somatosensory cortex during the course of pentobarbital (PB) anesthesia were examined. Temporal analysis of changes in the magnitude and latency of MEP and LEP, EEG activity, gross motor behaviors, and the tail flick response following laser stimulation before, during, and after PB administration (50 mg/kg, i.p.) was performed and correlated in chronically implanted rats. During the wakeful condition, there were two major cortical components each following mechanical stimulation (MEP1 and MEP2, n=17) and laser stimulation (LEP1 and LEP2, n=10), respectively. After PB administration, the positive peak in MEP1 was enhanced, and all other components disappeared. These components returned with different time courses. Two hours after PB administration, when the rat had spontaneous movements and flexor reflexes, LEP2 showed reversed polarity. MEP2 returned gradually 3 h after PB administration when the rat regained its ability to execute coordinated movements. After 4 h, LEP1 began to reappear and LEP2 returned to its negative polarity. We found that PB facilitated Abeta fiber-related cortical evoked potential (MEP1), while differentially inhibited Adelta and C fiber-related components (MEP2, LEP1 and LEP2). Characterization of these anesthesia-induced changes in cortical output may be useful in studying the neural basis of tactile and pain sensations.

Altered cellular but not humoral reactions in children with complicated enterovirus 71 infections in Taiwan

Enterovirus 71 (EV 71) infections have high neurovirulence and fatality. Immune responses were assessed in 78 patients with EV 71 infection. EV 71 meningoencephalitis occurred more frequently in younger children and in boys. C-reactive protein levels were not elevated, although total leukocyte counts were increased in these patients. The CD40-ligand expression on T cells significantly decreased in children with meningoencephalitis (P=.041). Polymorphism of the cytotoxic T lymphocyte antigen-4 (CTLA-4) at position 49 of exon 1 showed a higher frequency of G/G genotype in patients with EV 71 meningoencephalitis than in those without meningoencephalitis (18/31 vs. 14/47; P=.045) and in control subjects (18/31 vs. 25/93l; P=.007). Specific EV 71 neutralizing antibody titers were detectable but did not differ in children with and without meningoencephalitis in the acute and convalescent stages. Results from this study suggest that younger children with a certain CTLA-4 polymorphism and altered cellular but not humoral response may be linked to EV 71 meningoencephalitis.

Antibody-dependent enhancement of heterotypic dengue infections involved in suppression of IFNgamma production

Antibody-dependent enhancement has been implicated in some outbreaks of epidemic dengue hemorrhagic fever, however, the mechanism of antibody-dependent enhancement is not well known. This study was conducted to investigate the cross-protection and cross-enhancement of dengue-2 virus infections by dengue-1 immune sera. It was found that dengue-1 immune sera at 1:5 dilution (n = 12) could neutralize dengue-2 infections in BHK-21 cells, as assessed by a standard plaque-reduction neutralization assay. Two-thirds of the dengue-1 immune sera at 1:25 dilution demonstrated neutralizing effects for dengue-2 infections, whereas, non-immune sera revealed no neutralization for dengue-2 infections in BHK-21 cells. Human mononuclear leukocytes in response to dengue-2 infections elicited a T cell helper 1 (Th1) response revealing induction of IFNgamma but not IL-4 production. Dengue-1 immune sera did not neutralize dengue-2 infections in mononuclear leukocytes. Subneutralizing titers of dengue-1 immune sera at 1:250, but not at 1:10 dilution, enhanced dengue-2 infections in mononuclear leukocytes (1.2 +/- 0.7 x 10(4) vs. 2.8 +/- 0.3 x 10(2) PFU/ml). The enhancement of dengue-2 infections in mononuclear leukocytes by dengue-1 immune sera at 1:250 was associated with an increase in the lymphocyte proliferation index, and a decrease in IFNgamma production (56 +/- 24 vs. 12 +/- 3 pg/ml). The addition of IFNgamma (0.1 microg/ml) suppressed significantly the antibody-dependent enhancement induced by dengue-1 immune sera, whereas the presence of anti-IFNgamma F(ab)2 antibody augmented the antibody-dependent enhancement effect. Results from this study suggest that suppression of Th1 response may be involved in the antibody-dependent enhancement of heterotypic dengue infections. Better regulation of Th1/Th2 reactions may be useful for prevention of heterotypic immune enhancement of dengue infections.

A model of the real-time correlation of viral titers with immune reactions in antibody-dependent enhancement of dengue-2 infections

We simultaneously assessed dengue-2 virus (DEN-2) titers by real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR) and immune reactions including interleukin-4 (IL-4), interferon-gamma (IFN-gamma) and prostaglandin E(2) (PGE(2)) production by human mononuclear cells (MNLs) in a model of antibody-dependent enhancement (ADE). We found that DEN-1 immune sera at 1:100 and 1:250, but not those at 1:10 or control sera, enhanced DEN-2 infections in human MNLs as assessed by the fluorogenic RT-PCR technique. The enhanced profiles of DEN-2 infections determined by the RT-PCR in 6 h were reproducible by the standard plaque-forming unit (PFU) measurement established after 7 days. The ADE-enhanced DEN-2 titers determined by the RT-PCR were 5.5-33-fold higher than those detected by PFU assay, suggesting that total virions during infections were much higher than the viable ones detected by PFU assay. MNLs in response to DEN-2 infections had higher IFN-gamma and PGE(2) production. However, the enhancement of DEN-2 infections by DEN-1 immune sera in MNLs was not associated with further enhancement of IFN-gamma production. In contrast, the presence of subneutralizing DEN-1 immune sera that enhanced DEN-2 infections also enhanced PGE(2) but not IL-4 production. The results of this study suggest that ADE of DEN-2 infections associated with induction of immunosuppressive mediators such as PGE(2) and IL-4 can be simultaneously assessed in a real-time fashion.

Constrictive pericarditis associated with Marlex mesh. Two case reports

Two patients were referred to our hospital with constrictive pericarditis approximately 1 year after undergoing mitral valve repair at another institution. Both repairs had included the use of a pericardial substitute, Marlex mesh, to prevent adhesion and to facilitate possible reoperations. Computed tomography and cardiac catheterization were used to establish the diagnosis of constrictive pericarditis. During surgery, dense, thickened fibrous tissue, the result of a Marlex mesh-related reaction, was found tightly adhered to the epicardium in each of the patients. It appeared that the Marlex mesh, which had been inserted to facilitate reoperation, had contributed to the development of constrictive pericarditis.

A model to study antioxidant regulation of endotoxemia-modulated neonatal granulopoiesis and granulocyte apoptosis

Neonates with septicemia tend to develop granulocytopenia, which may, in part, be due to septic mediators such as oxygen free radicals and tumor necrosis factor alpha (TNF-alpha). Granulocytopenia may be caused by a decrease in granulocyte growth and/or an increase in granulocyte destruction. In the present study, we investigated antioxidant regulation of endotoxin-modulated neonatal granulopoiesis and granulocyte apoptosis. Using human umbilical cord blood (HUCB), we found that simulating endotoxemia in vitro elicited significant superoxide production within a few minutes. Endotoxin exposure suppressed colony-forming unit-granulocyte and monocyte formation in a dose-dependent fashion. Addition of antioxidants such as N-acetyl-cysteine could reverse the endotoxin suppression of colony-forming unit-granulocyte and monocyte formation (13 +/- 5 versus 75 +/- 5 colony-forming units/mL). Spontaneous in vitro granulocyte apoptosis in 6 h, as reflected by phosphatidylserine expression on the cell surface, was higher in granulocytes from HUCB than in those from adult blood (10.8 +/- 1.0% versus 5.6 +/- 1.2%). The addition of endotoxin or IL-8 to the cells in the in vitro model did not promote granulocyte apoptosis, but TNF-alpha, a major mediator of the effects of endotoxin, significantly induced granulocyte apoptosis in HUCB (control versus TNF-alpha: 8.9 +/- 1.2% versus 35.9 +/- 2.9%). Addition of the antioxidant N-acetyl-cysteine effectively blocked TNF-alpha-induced granulocyte apoptosis as demonstrated by DNA fragmentation. Results from these studies indicate that oxygen radicals are directly involved in endotoxin suppression of granulopoiesis, and indirectly promote granulocyte apoptosis, presumably through TNF-alpha-mediated action. Thus, under certain conditions, modulation of oxygen radical production in the blood may benefit neonates with granulocytopenia.

[Analysis of imidacloprid and damanlin by high performance liquid chromatography]

A new method for determination of imidacloprid and damanlin by using HPLC was established. It was carried out on a mu Bondapak C18 column (3.9 mm i.d. x 300 mm) with ACN-MeOH-H2O (60:10:30, V/V) as eluent and detected at 240 nm using photodiode array detector. The results of imidacloprid and damanlin were 3.71% and 15.65% respectively. The standard deviations for imidacloprid and damanlin were 0.88% and 0.76% respectively.

Algorithmic complexity as an index of cortical function in awake and pentobarbital-anesthetized rats

This study introduces algorithmic complexity to measure characteristics of brain functions. The EEG of the rat was recorded with implanted electrodes. The normalized complexity value was relatively independent of data length, and it showed a simpler and easier calculation characteristic than other non-linear indexes. The complexity index revealed significant differences among awake, asleep, and anesthetized states. It may be useful in tracking short-term and long-term changes in brain functions, such as anesthetized depth, drug effects, or sleep-wakefulness.

Comparison of touch- and laser heat-evoked cortical field potentials in conscious rats

Field potentials and multiunit activities from chronically implanted cortical electrodes were used to study tactile and nociceptive information processing from the tail of the rat. Fourteen stainless steel screws implanted in the skull were used as electrodes to record field potentials in different cortical areas. Electrical, mechanical, and laser pulses were applied to the tail to induce evoked cortical field potentials. Evoked responses were compared before and after sodium pentobarbital anesthesia (50 mg/kg, i.p.). In both electrical- and mechanical-evoked potential (EEP and MEP) studies, two major peaks were found in the conscious animal. The polarity of the late component was modified after pentobarbital anesthesia. In the laser-evoked potential (LEP) study, two distinct negative peaks were found. Both peaks were very sensitive to anesthesia. Following quantitative analysis, our data suggest that the first positive peak of EEP and MEP corresponded to the activation of the Abeta fiber, the second negative peak of MEP and the first peak of LEP corresponded to Adelta fiber activation, while the second peak of LEP corresponded to C fiber activation. The absolute magnitudes of all cortical components were positively related to the intensity of the stimulation. From spatial mapping analysis, a localized concentric source of field potential was observed in the primary somatosensory cortex (SI) only after activation of the Abeta fiber. Larger responsive cortical areas were found in response to Adelta and C fiber activation. In an intracortical recording experiment, both tactile and nociceptive stimulation evoked heightened unit activity changes at latencies corresponding to respective field potentials. We conclude that different cortical areas are involved in the processing of A and C fiber afferent inputs, and barbiturate anesthesia modifies their processing.

A multichannel system for recording and analysis of cortical field potentials in freely moving rats

A system has been developed to record and analyze the cortical electrical activity from 16 different sites in freely moving rats. The hardware includes a 16-channel amplifier system whose high input impedance, low noise, small size, light weight and shielded multistrand connecting cable allow high quality multichannel recording of field potentials. The software developed for this system consists of data acquisition, data analysis and topographic mapping of cortical-evoked potentials as well as electroencephalograms. Cortical field potentials evoked by CO2-laser stimulation were compared between wakeful and pentobarbital-treated conditions. To investigate the background interference produced by sleep spindle, three kinds of reference-free methods (the Wilson, local average and weighted average methods) were utilized to compare the coherence between field potentials obtained from two cerebral hemispheres using monopolar vs. reference-free recordings.

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.

Vagal innervation of the gastrointestinal tract arises from dorsal motor nucleus while that of the heart largely from nucleus ambiguus in the cat

The origin of medullary cells that form the cardiac vagal branch and the vagal branches in the lower thorax innervating the gastrointestinal (GI) tract was studied using horseradish peroxidase (HRP), a retrograde transport tracer in the cat. The distributions of parasympathetic postganglionic neurons of the heart were studied with acetylcholinesterase histochemistry. Intracardiac ganglionic neurons were found mainly in the connective tissue surrounding the base of the pulmonary arteries and in an area in and dorsal to the interatrial septum. Following injection of HRP into the subepicardum where most of the cardiac postganglionic neurons reside, 91% of the labelled neurons were found bilaterally distributed in the nucleus ambiguus (NA). A small population of labelled neurons was found in the dorsal motor nucleus of the vagus (DMV) and an intermediate zone (IZ) between the two nuclei. When HRP was injected into the left or right cardiopulmonary vagus branch, labelled neurons were found exclusively in the ipsilateral NA, DMV and IZ with a predominance in the NA. In the thorax, after they course around the heart, the left and right thoracic vagus nerves divides into a left and a right branch, respectively. The left branch of the left thoracic vagus joins the left branch of the right thoracic vagus to form the anterior vagus nerve at 3 cm above the diaphragm. The right branch of the right thoracic vagus nerve joins the right branch of the left thoracic vagus to form the posterior vagus nerve. After application of HRP into the right or the left branch of the left thoracic vagus, HRP labelled cells were found in the left DMV. Similarly, after application of HRP into the left or the right branch of the right thoracic vagus, labelled cells were found in the right DMV. On the other hand, when HRP was injected into the anterior vagus, labelled neurons were found bilaterally in the DMV. This suggests that all rostral branches of the thoracic vagus have their origin in the ipsilateral DMV, and intermixing occurs only at the caudal level near the diaphragm. Findings of the present experiments suggest that parasympathetic preganglionic neurons innervating the GI tract are located exclusively in the DMV while those of the heart are located mainly in the NA. Within the DMV, GI vagal neurons were found medially from the level 0-2.5 mm rostral to the obex. In contrast, cardiac vagal neurons were found in the lateral edge of the DMV at the level 0-1 mm rostral to the obex.

Effects of insulin on protein phosphorylation and protein kinase C activity in human malignant gliomas

Modulation of protein phosphorylation activities by insulin was investigated in glioma and normal glial cells. Insulin suppressed the in vitro protein phosphorylation of glioma cells in a dose-dependent manner while it stimulated that of meningiomas, neurilemmomas and glial cells. Although gliomas and glial cells contained different species of tyrosyl phosphoproteins before treatment, they expressed similar kinds of tyrosyl phosphoproteins in response to insulin. Insulin increased the activities of casein kinase II and total protein kinase C (PKC) in glioma and normal glial cells. The membrane-bound PKC activity in U373-MG cells was elevated by insulin. The PKC isozymes, including subtypes alpha, beta, delta, epsilon and gamma, were detected in gliomas, but few were found in glial cells. Insulin down regulated the cytosolic PKC-gamma and the membrane-bound PKC-epsilon proteins in gliomas. These results indicate that an altered insulin signaling pathway exists in human gliomas, which might involve differential regulation of PKC isozymes.

Transient induction of apoptosis in serum-starved glioma cells by insulin and IGF-1

Insulin has a wide variety of biological effects. One of them is a mitogen-like activity whereby cell proliferation is stimulated. In this study we found a heretofore unreported insulin-elicited transient apoptosis of glioma cells. When serum-starved glioma cells were fed with a fresh regular medium, in the 6- to 12-h post-starvation period, the growth rate as determined by cell number was significantly suppressed by insulin, although cell cycle progression and DNA synthesis were actually accelerated. Increase in apoptosis in those growth-retarded cultures was demonstrable by Hoechst staining, detection of histone-associated DNA fragment, and in situ cell death detection. Apoptosis occurred among cells in all stages of cell cycle. After 24 h post-starvation, insulin increased the total cell number like a typical growth-promoting mitogen. In this regard, IGF-1, but not EGF nor TGF-beta 1, behaved like insulin.

Metabolism of naphthalene, fluorene, and phenanthrene: preliminary characterization of a cloned gene cluster from Pseudomonas putida NCIB 9816

A modified cloning procedure was used to obtain large DNA insertions (20 to 30 kb) from Pseudomonas putida NCIB 9816 that expressed polycyclic aromatic hydrocarbon (PAH) transformation activity in Escherichia coli HB101. Four subclones (16 [in both orientations], 12, and 8.5 kb in size) were constructed from the initial clones. Naphthalene, fluorene, and phenanthrene transformations were investigated in these eight NCIB 9816 clones by a simple agar plate assay method, which was developed to detect and identify potential PAH metabolites. Results indicated that the necessary genes encoding the initial ring fission of the three PAHs in E. coli cells are located in an 8.5-kb EcoRI-XhoI portion, but the lower-pathway genes are not present in a 38-kb neighborhood region. These NCIB 9816 clones could transform naphthalene and phenanthrene to salicylic acid and 1-hydroxy-2-naphthoic acid, respectively. With the same clones, fluorene was degraded to 9-hydroxyfluorene, 9-fluorenone, and two unidentified compounds. Genetic similarity between the NAH7 upper-pathway genes and the cloned NCIB 9816 genes was confirmed by Southern blot DNA-DNA hybridization. In spite of this genetic similarity, the abilities of the two clusters to transform multiple PAHs were different. Under our experimental conditions, only the metabolites from naphthalene transformation by the NAH7 clone (pE317) were detected, whereas the NCIB 9816 clones produced metabolites from all three PAHs.

Weber syndrome caused by intracerebral hemorrhage in a hemophiliac boy

A rare occurrence of the Weber syndrome in childhood is reported. The patient was a 7-year-old hemophiliac with recurrent intracerebral bleeding into the right cerebral peduncle and pontine base. Left hemiparesis involving the face and tongue developed and was later accompanied by right oculomotor nerve palsy.