Nonlinearity vs nonlocality with emphasis on bandwidth broadening in semiconductor-based 1d metamaterials

The physics of nonlinear optical materials is incredibly versatile, with the design of novel materials and structures offering numerous degrees of freedom. Nevertheless, weak inherent nonlinearity of conventional optical materials continues to hinder the progress of a number of important applications. In this study, we delve into the realm of broadband enhancement of nonlinearity within one-dimensional (1d) plasmonic metamaterials, exploring its intricate connection with nonlocality. Specifically, we introduce a phenomenological framework for quantifying the effective third-order nonlinear susceptibility of 1d multiphase plasmonic nanostructures, utilizing heavily doped semiconductors, and subsequently applying this approach using realistic material parameters. Both direct and inverse problems of nonlinearity enhancement have been addressed. Our findings demonstrate a remarkable capability to significantly augment the third-order nonlinear susceptibility across a defined frequency range, while concurrently gauging the impact of nonlocality on this enhancement.

Automated Detection, Segmentation, and Tracking of Brain Metastases in Repeated Courses of Stereotactic Radiosurgery Using Integrated Artificial Intelligence

PURPOSE/OBJECTIVE(S)

Salvage stereotactic radiosurgery (SRS) for distant brain metastases has been demonstrated as a safe and effective approach for intracranial recurrences after initial SRS. However, accurate tumor detection and segmentation among responding tumors within the irradiated parenchyma can be challenging. The requirement for the registration and reference to the previous course of SRS is very time-consuming and suffers significant inter and intra-reader variability. Artificial intelligence (AI)-assisted system has been proven to improve the accuracy and efficiency in the clinical flow of de-novo SRS. We hypothesize that an integrated AI system can facilitate an automated tumor contouring process for repeated SRS.

MATERIALS/METHODS

Three patients who underwent their third course of SRS to brain metastases were selected for the pioneering works. They have had two sessions of SRS with a mean lesion number of 4 and 3.7, respectively. VBrain, an FDA-approved brain tumor management AI platform, was used to co-registered serial MR scans and automatically identify, track, and contour brain metastases for each course of SRS. The AI also indicated new lesions and treated lesions for each course. Three radiation oncologists experienced in brain SRS contoured the gross tumor volumes (GTVs) of the third course of SRS in two reader modes (assisted then unassisted) with a memory washout period of one week between each section. The segmentation ground truth was established through consensus among the three experts. Lesion-wise sensitivity, contouring accuracy, and consuming time were compared between the two contouring modes.

RESULTS

In each patient, there were 15, 11, and 9 metastases, with a median diameter of 4.72 (95% CI: 4.05, 6.91) mm. The mean lesion-wise sensitivity was 96.96±2.47% with AI assistance and 76.90 ± 7.10% without assistance. There were two false-positive lesions in the assisted read, resulting in a low average false-positive rate of 0.67 per patient, while no false positive for the unassisted mode. AI assistance improved contouring accuracy. The median Dice similarity coefficient (DSC) was 0.71 (95% CI: 0.55, 0.87) for assisted contouring and 0.65 (95% CI: 0.46, 0.85) for unassisted contouring. We also use average Hausdorff distance (HD) to measure segmentation results. The mean HD was 0.72± 0.13 mm versus 0.73±0.08 mm for the two contouring modes (p = 0.02) Furthermore, the median contouring time per case was significantly shorter with AI assistance than without assistance (20.8 minutes vs. 29.8 minutes; p < 0.001), corresponding to a 43.2% time-saving.

CONCLUSION

Our results suggest that the integration of an AI-based system into repeated brain SRS can significantly improve the accuracy and efficiency of tumor detection and segmentation. This approach has the potential to streamline the treatment planning process for salvage SRS.

[Changes of BK(Ca) on vascular striaepericytes of D-galactose-induced aging model in guinea pigs]

Objective: The aging model of guinea pigs induced by D-galactose was set up to investigate the changes of BK(Ca) expression and function on cochlear pericytes and their relationship with age-related hearing loss. Methods: Thirty healthy 8-week-old guinea pigs were randomly divided into three groups, with 10 in each group: D-galactose aging model group, subcutaneous injection of D-galactose (500 mg/kg) daily for 6 weeks; saline control group, the same amount of saline was injected into the neck of the aging model group for 6 weeks; the blank control group, no treatment was performed. The threshold of auditory brainstem response (ABR) was detected. The content of BK(Ca) in the perivascular cells of the guinea pig cochlear cells was detected by immunofluorescence technique. The changes of peripheral current density and BK(Ca) current were detected by patch clamp technique. The data were analyzed by GraphPad Prism software. Results: Compared with the saline group and the control group, the ABR threshold and the amplitude of the wave I were significantly decreased in the aging model group, and the difference was statistically significant (P<0.01). Compared with the control group, the expression of BK(Ca) in the vascular pericytes of guinea pigs in the aging model group was significantly reduced (1.00±0.08 vs 0.27±0.03,the difference was statistically significant P<0.01), and the cell current density and BK(Ca) net current value were also significantly reduced with statistically significant (P<0.01). Conclusions: D-galactose can successfully induce guinea pig aging model, in which BK(Ca) expression decreases and net current value decreases in pericytes of cochlear striavascularis, and changes in BK(Ca) expression and function may be related to age-related hearing loss.

Periorbital erythema and swelling as a presenting sign of lupus erythematosus in tertiary referral centers and literature review

Background Cutaneous lupus erythematosus (CLE) includes a broad range of dermatologic manifestations. Periorbital involvement, however, is a relatively rare clinical presentation of CLE. Objectives This clinical study aimed to investigate the characteristics of this unique presentation of CLE in tertiary medical centers. Methods We enrolled patients with periorbital erythema and swelling as the presenting sign of lupus erythematosus, from January 2003 to November 2017, using the data of 553 pathologically proven CLE cases from the registration database of the Chang Gung Memorial Hospitals in Taiwan. Results We enrolled a total of 25 patients. The mean age was 46.7 years and 68% of the patients were female. Most of the patients (84.0%) presented with unilateral involvement, with the left orbit involved in 15 patients (60%); the upper eyelid was the most frequently involved (72%). Mean duration between the onset of clinical manifestations and the diagnosis of CLE was approximately 59 weeks. Nineteen patients had been previously misdiagnosed. All patients had features compatible with CLE on histopathological examination. In contrast, laboratory analysis of the autoimmune profile often revealed negative results, including those for antinuclear antibodies (25%). Notably, anti-SSA/SSB (45.5%) showed the highest positive rate. During follow-up, six patients developed systemic lupus erythematosus (SLE) and two patients developed Sjögren syndrome. Conclusions The diagnosis of CLE presenting as periorbital erythema and swelling is often delayed because of clinical mimicry and the high proportion of negative results on autoantibody tests. Increased clinical suspicion and prompt histopathological examination are crucial for early diagnosis. Moreover, one-fourth of the patients ultimately developed SLE, which highlights the importance of clinical awareness.

Meta-analysis of cardiovascular toxicity risks in cancer patients on selected targeted agents

PURPOSE

The purpose was to estimate the risk and severity of cardiovascular toxicities associated with selected targeted agents.

METHODS

We searched English-language literature for randomized clinical trials published between January 1, 2000 and November 30, 2013 of targeted cancer therapy drugs approved by the FDA by November 2010. One hundred ten studies were eligible. Using meta-analytic methods, we calculated the relative risks of several cardiovascular toxicities [congestive heart failure (CHF), decreased left ventricular ejection fraction (DLVEF), myocardial infarction (MI), arrhythmia, and hypertension (HTN)], adjusting for sample size using the inverse-variance technique. For each targeted agent and side effect, we calculated the number needed to harm.

RESULTS

Regarding CHF, trastuzumab showed significantly greater risk of all-grade and high-grade CHF. There was significant increased risk of all-grade DLVEF with sorafenib, sunitinib, and trastuzumab and high-grade DLVEF with bevacizumab and trastuzumab. Sorafenib was associated with significant increased all-grade risk of MI based on one study. None was associated with high-grade risk of MI or increased risk of arrhythmia. Bevacizumab, sorafenib, and sunitinib had significant increased risk of all-grade and high-grade HTN.

CONCLUSIONS

Several of the targeted agents were significantly associated with increased risk of specific cardiovascular toxicities, CHF, DLVEF, and HTN. Several had significant increased risk for high-grade cardiovascular toxicities (CHF, DLVEF, and HTN). Patients receiving such therapy should be closely monitored for these toxicities and early and aggressive treatment should occur. However, clinical experience has demonstrated that some of these toxicities may be reversible and due to secondary effects.

An energy adjustable linearly polarized passively Q-switched bulk laser with a wedged diffusion-bonded Nd:YAG/Cr⁴⁺:YAG crystal

An energy adjustable passively Q-switched laser is demonstrated with a composite Nd:YAG/Cr⁴⁺:YAG crystal by applying a wedged interface inside the crystal. The theoretical model of the monolithic laser resonator is explored to show the energy adjustable feature with different initial transmissions of the saturable absorber at the horizontal axis. By adjusting the pump beam location across the Nd:YAG crystal, the output pulse energy can be flexibly changed from 10.9 μJ to 17.6 μJ while maintaining the same output efficiency. The polarization state of the laser output is found to be along with the polarization of the C-mount pump diode. Finally, the behavior of the multi-transverse-mode oscillation is also discussed for eliminating the instability of the pulse train.

YM155 down-regulates survivin and XIAP, modulates autophagy and induces autophagy-dependent DNA damage in breast cancer cells

BACKGROUND AND PURPOSE

The aim of this study was to determine the potency and molecular mechanism of action of YM155, a first-in-class survivin inhibitor that is currently under phase I/II clinical investigations, in various drug-resistant breast cancers including the oestrogen receptor positive (ER(+) ) tamoxifen-resistant breast cancer and the caspase-3-deficient breast cancer.

EXPERIMENTAL APPROACH

The potency of YM155 in SK-BR-3, MDA-MB-231, MCF7 and its tamoxifen-resistant sublines, TamR6, TamR7, TamR8, TamC3 and TamC6, were determined by MTT assay. Western blot analysis, flow cytometric analysis, reverse transcription-PCR, fluorescent microscopy and comet assay were used to determine the molecular mechanism of action of YM155 in different breast cancer cell lines.

KEY RESULTS

YM155 was equally potent towards the parental ER(+) /caspase-3-deficient MCF7 breast cancer cells and its tamoxifen-resistant sublines in vitro. The ER(-) /HER2(+) SK-BR-3 breast cancer cells and the triple-negative/caspase-3-expressing metastatic aggressive MDA-MB-231 breast cancer cells were also sensitive to YM155 with IC50 values in the low nanomolar range. Targeting survivin by YM155 modulated autophagy, induced autophagy-dependent caspase-7 activation and autophagy-dependent DNA damage in breast cancer cells. Interestingly, YM155 also induced XIAP degradation and the degradation of XIAP might play an important role in YM155-induced autophagy in breast cancer cells.

CONCLUSIONS AND IMPLICATIONS

YM155 is a potent survivin inhibitor that has potential for the management of various breast cancer subtypes regardless of the expression of ER, HER2 and caspase-3. Importantly, this study provides new insights into YM155's molecular mechanism of action and therapeutic potential in the treatment of tamoxifen-resistant breast cancer.

Evaluation of the effects of nanoscale zero-valent iron (nZVI) dispersants on intrinsic biodegradation of trichloroethylene (TCE)

In this study, the biodegradability of nanoscale zero-valent iron (nZVI) dispersants and their effects on the intrinsic biodegradation of trichloroethylene (TCE) were evaluated. Results of a microcosm study show that the biodegradability of three dispersants followed the sequence of: polyvinyl alcohol-co-vinyl acetate-co-itaconic acid (PV3A) > polyoxyethylene (20) sorbitan monolaurate (Tween 20) > polyacrylic acid (PAA) under aerobic conditions, and PV3A > Tween 20 > PAA under anaerobic conditions. Natural biodegradation of TCE was observed under both aerobic and anaerobic conditions. No significant effects were observed on the intrinsic biodegradation of TCE under aerobic conditions with the presence of the dispersants. The addition of PAA seemed to have a slightly adverse impact on anaerobic TCE biodegradation. Higher accumulation of the byproducts of anaerobic TCE biodegradation was detected with the addition of PV3A and Tween 20. The diversity of the microbial community was enhanced under aerobic conditions with the presence of more biodegradable PV3A and Tween 20. The results of this study indicate that it is necessary to select an appropriate dispersant for nZVI to prevent a residual of the dispersant in the subsurface. Additionally, the effects of the dispersant on TCE biodegradation and the accumulation of TCE biodegrading byproducts should also be considered.

A semi-automated vascular access system for preclinical models

Murine models are used extensively in biological and translational research. For many of these studies it is necessary to access the vasculature for the injection of biologically active agents. Among the possible methods for accessing the mouse vasculature, tail vein injections are a routine but critical step for many experimental protocols. To perform successful tail vein injections, a high skill set and experience is required, leaving most scientists ill-suited to perform this task. This can lead to a high variability between injections, which can impact experimental results. To allow more scientists to perform tail vein injections and to decrease the variability between injections, a vascular access system (VAS) that semi-automatically inserts a needle into the tail vein of a mouse was developed. The VAS uses near infrared light, image processing techniques, computer controlled motors, and a pressure feedback system to insert the needle and to validate its proper placement within the vein. The VAS was tested by injecting a commonly used radiolabeled probe (FDG) into the tail veins of five mice. These mice were then imaged using micro-positron emission tomography to measure the percentage of the injected probe remaining in the tail. These studies showed that, on average, the VAS leaves 3.4% of the injected probe in the tail. With these preliminary results, the VAS system demonstrates the potential for improving the accuracy of tail vein injections in mice.

A fractal dimensional approach to successful evaluation of apical healing

AIM

To evaluate whether the initial healing of apical radiolucencies 1 year after root canal treatment could be quantitatively identified by the change in fractal dimension (FD) values for the eventually completely healed cases.

METHODOLOGY

Twenty-six patients with successful root canal treatment were recruited. All teeth were associated with complete healing either before or at 1 year following treatment (six of 26) or still undergoing healing at 1 year after treatment but completely healed thereafter (20 of 26). Two radiographs were selected for the same patient, one taken before treatment and the other taken 1 year after treatment. Eight regions of interests (ROIs) were selected from each radiograph, two as the experimental group located close to the infected root apex, two as the control group in the healthy bone and the other four in the healthy bone ensuring the image quality.

RESULTS

Based on the FD values of the four ROIs in the healthy bone, the two radiographs were confirmed to have been taken with similar projection angles and exposure. The FD values were shown to significantly increase (P = 0.006) and decrease (P = 0.000) around the root apex and the neighbouring region of the apical lesion, respectively.

CONCLUSION

Changes in fractal dimension values may serve as a necessary condition to quantitatively indicate the initial healing status 1 year after root canal treatment.

Difficulties in organ procurement and transplantation in the aboriginal minority people in Taiwan

BACKGROUND

Aboriginal people (AP) are a minority group in Taiwan. Little information on their perspectives on organ transplantation (OT) is available. Their rights for organ donation (OD) and as OT recipients (OTR) are constrained as a vulnerable population in society. This research sought to explore various Highland Aborigine Tribes beliefs systems and concepts related to OT.

METHODS

We employed a qualitative design on a purposive sample including seven categories of Taiwanese AP. Data collected by face-to-face interviews were evaluated by content analysis.

RESULTS

Seventy-five informants (45 female and 30 males) of 18 to 82 years from seven tribes completed interviews: Bunun (n = 20), Shao (n = 18), Tsou (n = 15), Amis (n = 12), Truku (n = 4), Rukai (n = 3), and Puyuma (n = 3). Of there, 33% had no idea of OT. All informants reported lack of knowledge of OD, organ procurement, and OTR. Eighty percent (45-82 years) had no willingness for OD or OTR; others might consult family members and health professionals (HP) to learn about OT. Seven hindering factors were identified: (1) having no background of OT; (2) limited impressions obtained from television news reports; (3) negative concepts of donating one's organs to others; (4) OT concepts contrast with cultural meanings of death; (5) possibility of being stigmatized; (6) fear of being rejected by others; and (7) HP had never mentioned OT.

CONCLUSIONS

Taiwan APs' perspectives of OT concepts showed the majority to be unfamiliar with the concept and benefits of OT. Future research is necessary to explore the possible avenues to facilitate communications between HP and AP leaders, as well as elders in each AP category in Taiwan.

Homeobox genes in obsessive-compulsive disorder

BACKGROUND

Despite evidence that obsessive-compulsive disorder (OCD) is a familial neuropsychiatric condition, progress aimed at identifying genetic determinants of the disorder has been slow. The OCD Collaborative Genetics Study (OCGS) has identified several OCD susceptibility loci through linkage analysis.

METHODS

In this study we investigate two regions on chromosomes 15q and 1q by first refining the linkage region using additional short tandem repeat polymorphic (STRP) markers. We then performed association analysis on single nucleotide polymorphisms (SNP) genotyped (markers placed every 2-4 kb) in the linkage regions in the OCGS sample of 376 rigorously phenotyped affected families.

RESULTS

Three SNPs are most strongly associated with OCD: rs11854486 (P = 0.00005 [0.046 after adjustment for multiple tests]; genetic relative risk (GRR) = 11.1 homozygous and 1.6 heterozygous) and rs4625687 [P = 0.00007 (after adjustment = 0.06); GRR = 2.4] on 15q; and rs4387163 (P = 0.0002 (after adjustment = 0.08); GRR = 1.97) on 1q. The first SNP is adjacent to NANOGP8, the second SNP is in MEIS2, and the third is 150 kb between PBX1 and LMX1A.

CONCLUSIONS

All the genes implicated by association signals are homeobox genes and are intimately involved in neurodevelopment. PBX1 and MEIS2 exert their effects by the formation of a heterodimeric complex, which is involved in development of the striatum, a brain region involved in the pathophysiology of OCD. NANOGP8 is a retrogene of NANOG, a homeobox transcription factor known to be involved in regulation of neuronal development. These findings need replication; but support the hypothesis that genes involved in striatal development are implicated in the pathogenesis of OCD.

Lifetime exposure to cigarette smoking and the development of adult-onset atopic dermatitis

BACKGROUND

Adult-onset atopic dermatitis (AD) has recently been recognized as a distinct disease entity, but its risk factors have not yet been clearly defined. Although gestational and perinatal exposure to tobacco smoking may be associated with the development of classic AD, the association between active/passive smoking and adult-onset AD remains controversial.

OBJECTIVES

To determine if exposure to smoking, including environmental tobacco smoke (ETS), is associated with the risk of adult-onset AD.

METHODS

Tobacco smoking and exposure to ETS were measured in a case-control association analysis in 83 patients with physician-diagnosed adult-onset AD and 142 age- and sex-matched controls.

RESULTS

Multiple logistic regression analyses showed that, among the potential environmental risk factors, both current and ever smoking were significant risk factors for adult-onset AD [odds ratio (OR) 4·994 and 3·619, respectively], compared with never smoking. Also, packs per year was significantly associated with adult-onset AD (OR 1·058, 95% confidence interval 1·028-1·089), suggesting a lifelong cumulative risk in current smokers. Moreover, nonsmokers with adult-onset AD reported significantly more exposure to ETS.

CONCLUSIONS

Early and/or current exposure to cigarette smoking may contribute cumulatively to the development of adult-onset AD. Exposure to ETS in childhood is associated with the development of adult-onset AD. Adults should be discouraged from smoking to prevent adult-onset AD in themselves and their family members.

The origin of the white Roman goose

In order to avoid interference from nuclear copies of mitochondrial DNA (numts), mtDNA of the white Roman goose (domestic goose) was extracted from liver mitochondria. The mtDNA control region was amplified using a long PCR strategy and then sequenced. Neighbor-joining, maximum parsimony, and maximum-likelihood approaches were implemented using the 1,177 bp mtDNA control region sequences to compute the phylogenetic relationships of the domestic goose with other geese. The resulting identity values for the white Roman geese were 99.1% (1,166/1,177) with western graylag geese and 98.8% (1,163/1,177) with eastern graylag geese. In molecular phylogenetic trees, the white Roman goose was grouped in the graylag lineage, indicating that the white Roman goose came from the graylag goose (Anser anser). Thus, the scientific name of the white Roman goose should be Anser anser 'White Roman.'

Lack of association between AKT1 variances versus clinical manifestations and social function in patients with schizophrenia

The elucidation of genotype-phenotype relationships in psychiatric research is at an early stage. V-akt murine thymoma viral oncogene homolog 1 (AKT1) is a serine/threonine kinase known as protein kinase B. Emerging studies have implicated the role of AKT1 in pathogenesis of schizophrenia; however, the findings have not been consistent. This study aims to examine the association of AKT1 polymorphisms with drug-free and post-treatment symptomatology and social function in patients with schizophrenia. One hundred and twenty newly hospitalised patients with acutely exacerbated schizophrenia who had never been treated by atypical antipsychotics were recruited. They received optimal treatment of risperidone for up to 42 days in the inpatient research unit. Clinical manifestations were monitored by Positive and Negative Syndrome Scale (PANSS) and social function by Nurses' Observation Scale for Inpatients Evaluation (NOSIE). Patients were genotyped for eight AKT1 Single Nucleotide Polymorphism (SNPs), which have been previously investigated for association with schizophrenia. At drug-free status and after best possible treatment of risperidone, genotypes of each SNP did not influence performances in NOSIE, PANSS-total, -positive, -negative and -general psychopathology profiles. These results suggest that AKT1 does not play a significant role in clinical and functional manifestations in patients with schizophrenia who receive risperidone treatment. Future research should also focus on the relationships between genotypes of other susceptibility genes and phenotypes or functional outcomes of schizophrenia.

Intra-articular magnesium sulfate (MgSO4) reduces experimental osteoarthritis and nociception: association with attenuation of N-methyl-D-aspartate (NMDA) receptor subunit 1 phosphorylation and apoptosis in rat chondrocytes

OBJECTIVE

To study the effects of intra-articular injection of magnesium sulfate (MgSO(4)) on the development of osteoarthritis (OA) and to examine concomitant changes in the nociceptive behavior of rats.

METHODS

OA was induced in Wistar rats with intra-articular injection of collagenase (500 U) in the right knee; the left knee was left untreated. In the OA+MgSO(4) group (n=7), the treated knee was injected with 500-microg (0.1-ml) MgSO(4) twice a week for 5 consecutive weeks starting at 1 week after collagenase injection; in the OA group (n=7), the same knee was injected with the same amount of physiological normal saline. In the MgSO(4) group (n=6), naïve rats received only MgSO(4) injections; in the control group (n=6), naïve rats received only physiological normal saline injections. Nociceptive behavior (mechanical allodynia and thermal hyperalgesia) on OA development was measured before and at 1, 2, 4, 6, and 8 weeks after collagenase injection, following which the animals were sacrificed. Gross morphology and histopathology were examined in the femoral condyles, tibial plateau, and synovia. Immunohistochemical analysis was performed to examine the effect of MgSO(4) on N-methyl-D-aspartate (NMDA) receptor subunit 1 phosphorylation (p-NR1) and apoptosis in the articular cartilage chondrocytes.

RESULTS

OA rats receiving intra-articular MgSO(4) injections showed a significantly lower degree of cartilage degeneration than the rats receiving saline injections. MgSO(4) treatment also suppressed synovitis. Mechanical allodynia and thermal hyperalgesia showed significant improvement in the OA+MgSO(4) group as compared to the OA group. Moreover, MgSO(4) attenuated p-NR1 and chondrocyte apoptosis in OA-affected cartilage.

CONCLUSIONS

Our results indicate that local intra-articular administration of MgSO(4) following collagenase injection in an experimental rat OA model (1) modulates chondrocyte metabolism through inhibition of cell NMDA receptor phosphorylation and apoptosis, (2) attenuates the development of OA, and (3) concomitantly reduces nociception.

Gender differences in genetic linkage and association on 11p15 in obsessive-compulsive disorder families

Several clinical and genetic studies have reported gender differences in obsessive-compulsive disorder (OCD). Previously, we conducted a linkage genome scan using multipoint allele-sharing methods to test for linkage in 219 families participating in the OCD Collaborative Genetics Study. When these families were stratified by proband's gender, suggestive linkage to chromosome 11p15 at marker D11S2362 (KAC(all) = 2.92, P = 0.00012) was detected in families with male probands, but not in the ones with female probands. We have since conducted fine mapping with a denser microsatellite marker panel in the region of 11p15, and detected a significant linkage signal at D11S4146 (KAC(all) = 5.08, P < 0.00001) in the families of male probands. Subsequently, 632 SNPs were genotyped spanning a 4.0 Mb region of the 1 LOD unit interval surrounding the linkage peak in the original families and an additional 165 families. Six SNPs were associated with OCD (P < 0.001): two SNPs were identified when all the families were included, and four SNPs only in male proband families. No SNP showed significant association with the OCD phenotype only in the families with a female proband. The results suggest a possible gender effect in the etiology of OCD.

Aligned Er-doped ZnO nanorod arrays with enhanced 1.54 microm infrared emission

Vertically aligned Er-doped ZnO nanorod arrays with sharp and intense 1.54 microm infrared emission have been fabricated on Si substrates through a well controlled spin-coating and annealing process. The synthesis method is advantageous for synthesizing ZnO nanostructures free from structural defects, capability for large-scale production, minimum equipment requirement and product homogeneity. Er atoms were found to incorporate into ZnO lattice from XRD, ESCA, TEM, STEM/EDS and PL measurements. The single-crystal Er-doped nanorods maintained their high microstructural quality after annealing for 4 hr at 800 degreesC. The intensity of 1.54 microm infrared emission was found to be correlated with the deep level green emission. The enhanced luminescence intensity and best ever narrow wavelength distribution of Er-doped ZnO nanorod arrays at 1.54 microm emission will be conductive to applications in optoelectronic devices and optical communications.

Broadband and omnidirectional antireflection employing disordered GaN nanopillars

Disordered GaN nanopillars of three different heights: 300, 550, and 720 nm are fabricated, and demonstrate broad angular and spectral antireflective characteristics, up to an incident angle of 60? and for the wavelength range of lambda=300-1800 nm. An algorithm based on a rigorous coupled-wave analysis (RCWA) method is developed to investigate the correlations between the reflective characteristics and the structural properties of the nanopillars. The broadband and omnidirectional antireflection arises mainly from the refractive-index gradient provided by nanopillars. Calculations show excellent agreement with the measured reflectivities for both s- and p- polarizations.

Complete dechlorination of tetrachloroethylene by use of an anaerobic Clostridium bifermentans DPH-1 and zero-valent iron

A laboratory test was conducted to examine the combined effect of an anaerobic Clostridium bifermentans DPH-1 and addition of zero-valent iron (Fe0) on the reductive dechlorination of tetrachloroethylene (PCE). In addition, the dechlorination of cis-1,2-dichloroethylene (cDCE) produced from PCE was examined using Fe0. The cDCE produced was completely dechlorinated to non-toxic end products, mostly, ethylene by a subsequent chemical reductive process. Production of ethylene was dramatically increased with increase of initial cDCE concentration in the range of 10.3 microM to 928 microM (1.0-90 mg l(-1)) and the velocity constant was calculated to be 0.38 day(-1). On the other hand, the combined use of strain DPH-1 and Fe0 showed the most significant effect on the initial PCE dechlorination, but cohesion of Fe0 was found to inhibit the dechlorination rate of PCE. It is thought that phosphoric acid iron contained in a medium forms film on the surface of iron particle, so oxidation of iron is inhibited.

Outcome of antenatally diagnosed cardiac rhabdomyoma: case series and a meta-analysis

OBJECTIVES

Rhabdomyoma, the most common primary fetal cardiac tumor, is often associated with tuberous sclerosis (TS). We aimed to evaluate outcome in cases diagnosed with fetal cardiac rhabdomyoma.

METHODS

This study presents 11 cases with fetal cardiac rhabdomyoma. In addition, all relevant published cases of antenatally diagnosed cardiac rhabdomyoma since 1982 were identified from MEDLINE. We evaluated the following risk factors associated with clinical impact and perinatal outcome: family history of TS, gestational age at diagnosis, tumor size, site and number of tumors, tumor progression, and associated intracardiac and extracardiac anomalies.

RESULTS

In this meta-analysis, 138 cases, including nine newly added by us, were categorized into Group A (107 live babies) and Group B (16 neonatal deaths and 15 intrauterine fetal deaths). Univariate analysis showed that large cardiac tumors (P < 0.0001), fetal dysrhythmia (P < 0.0001) and hydrops (P < 0.0001) were strong predictors of neonatal outcome. Tumor size >or= 20 mm (relative risk (RR), 20.6; 95% CI, 2.2-195.9; P = 0.009) and fetal dysrhythmia (RR, 13.6; 95% CI, 2.9-62.3; P = 0.001) were significantly associated with neonatal morbidity. TS, present in 85/133 (63.9%) cases, was significantly associated with multiple cardiac tumors (P < 0.0001) and family history of TS (P = 0.02).

CONCLUSIONS

Large tumor size and hydrops are significantly associated with poor neonatal outcome, whereas family history of TS and multiple fetal cardiac tumors are associated with TS. Any sonographic detection of a fetal cardiac tumor should warrant further investigation for the possible presence of associated disorders.

Comparison of two-phase (201)Tl SPECT with chest CT to differentiate thoracic malignancies from benign lesions

AIM

This study was conducted to compare the performance of (201)Tl single photon emission computed tomography ((201)Tl SPECT) with chest computed tomography (CT) in differentiating thoracic malignancies from benign lesions.

METHODS

One hundred and seventy patients with confirmed diagnostic thoracic lesions found in chest radiographs were prospectively examined by (201)Tl SPECT. The performance of (201)Tl SPECT in differentiating thoracic malignancies from benign lesions was evaluated in 161 patients with a measurable retention index (RI), using the region-of-interest method. Chest CT scans were retrospectively collected from 165 patients and were interpreted by two independent observers.

RESULTS

The areas under the receiver operating characteristics curves were 0.85 using the RI value to differentiate thoracic malignancies from benign lesions. The sensitivity, specificity, and accuracy were 71.9%, 83.1%, and 76.4%, respectively, with a cutoff level for the RI set at 20%. Similarly, the sensitivity, specificity and accuracy of chest CT scans to differentiate malignancies from benign lesions were 78.2%, 69.7% and 74.9%, respectively. Focusing on patients with concordant results in both (201)Tl SPECT and chest CT scans, we can differentiate thoracic malignancies from benign lesions with a sensitivity of 89.1%, a specificity of 90%, and an accuracy of 89.4%.

CONCLUSION

Both (201)Tl SPECT and chest CT scans are useful imaging tools in differentiating thoracic malignancies from benign lesions, with an accuracy of around 75%. By combining these two image modalities, the accuracy improves to 89.4%, which may circumvent the need for invasive procedures for certain equivocal cases, using either single image alone.

Diode-pumped, actively internal-Q-switched Nd:MgO:PPLN laser

We demonstrated a laser-diode-pumped, electro-optically internal-Q-switched laser system radiating at 1.085 mum fabricated using a periodically poled Nd:MgO:LiNbO3 (Nd:MgO:PPLN) crystal. The Nd:MgO:PPLN is 17-mm long and has a 12-mm long, 13.6-mum period polarization-mode quasi-phase-matching (PM QPM) grating section functioning as the Q-switch of the laser system. When the Nd:MgO:PPLN Q-switch was driven by a 260-V voltage pulse train at 5 kHz, we obtained laser pulses of pulse energy >2.45 muJ and a pulse width of ~28 ns, corresponding to a laser peak power of ~88 W, from this internal-Q-switched laser system with 2% output coupling at an absorbed diode pump power of 0.61 W.

Fourier analysis of surface plasmon waves launched from single nanohole and nanohole arrays: unraveling tip-induced effects

The authors report the investigation of surface plasmon waves (SPW) generated by single nanohole and nanohole arrays. Scattering-type scanning near-field microscopy is used to directly observe near-field distribution. The images after Fourier transformation display characteristic patterns that match with the derived analytic formula. The correspondence helps to identify the role of the scanning tip in generating SPW, making possible of the removal of this tip-induced effect. This study provides a means to perform in-depth investigation on surface plasmon polaritons.

Enhancing intensity of emitted light from a ring by incorporating a circular groove

We fabricated a ring containing a single circular groove (RCG) on silver film and which was supported on a glass substrate. We found that by changing the mean radius of the circular groove, the light intensity emitted from the RCG can be modulated by using the scattering light from the circular groove. In addition, we also fabricated circular grooves with the same depth but of different widths so that we could examine the scattering light behavior of the grooves. Herein, we propose a theoretical model which takes into account the amplitude modulation of the cylindrical waves. Our results showed that our proposed model agreed well with the experimental results.

Prednisolone oral solution plus inhaled procaterol for acute asthma in children: a double-blind randomized controlled trial

BACKGROUND

To evaluate the efficacy of prednisolone sodium phosphate oral solution plus inhaled procaterol in the treatment of acute asthma in children.

METHODS

Forty-three patients aged 6 to 12 years with an acute exacerbation of asthma were double-blind randomized into one of two treatment groups in a 1:1 ratio:1) prednisolone oral solution +placebo tablets + procaterol MDI or 2) prednisolone tablets +placebo oral solution + procaterol MDI, all given three times daily for 7 days. Peak expiratory flow rate (PEFR), 24-hour reflective asthma symptom scores, spirometry and pulmonary index score (PIS) were recorded before and after treatment. Net changes in PEFR, symptom score, PIS, Forced Expiratory Volume in the first second (FEV1), FEV1/forced vital capacity (FVC), forced expiratory flow between 25 and 75 percent of the forced vital capacity (FEF(25-75%)) (before and after treatment) and global assessment by the investigator and the subjects or their parents were analyzed.

RESULTS

The two groups were statistically similar at baseline values of these parameters. After a 7-day course of treatment, the net change of PEFR before and after treatment was significantly improved in both groups, but there was no significant difference in the net change of PEFR between the two groups (57.27+/-31.44 L/min vs. 54.29 +/-30.04 L/min, difference 2.99 +/-30.76 L/min, mean +/-SD, P=0.752). The net change in PIS and total symptom score did not differ between the two groups (P=0.091 and 0.827, respectively). Similarly, the FEV1, FEV1/FVC and FEF25-75% all improved with either treatment, and neither group was significantly superior to the other group (P=0.162, 0.48 and 0.081, respectively). Global assessment by the investigator and the subjects or their parents at the end of study indicated an essentially comparable result.

CONCLUSIONS

Prednisolone sodium phosphate oral solution plus inhaled procaterol is as efficacious as prednisolone tablets plus inhaled procaterol in the management of acute asthma in children.

Factors influencing the successful treatment of infectious pulmonary tuberculosis

SETTING

Achieving successful treatment of infectious pulmonary tuberculosis (PTB) could reduce the spread of tuberculosis (TB) and the emergence of multidrug resistance.

OBJECTIVE

To explore factors associated with successful treatment for sputum-positive PTB.

DESIGN

This study used a population-based retrospective cohort design. All PTB patients residing in southern Taiwan recorded in the tuberculosis registry from 1 January to 30 June 2003 were identified. Each patient's medical record was requested from treating hospitals and retrospectively reviewed for 15 months after the date PTB was confirmed.

RESULTS

There were 399 PTB patients included in the study. Factors significantly associated with successful treatment included treatment by pulmonologists (OR 1.93), receiving directly observed therapy (DOT) (OR 1.76) and receiving treatment at the chest hospital (OR 5.41). Patients of advanced age were less likely to achieve treatment success (OR 0.97). Among patients treated by pulmonologists, those treated at the chest hospital had a significantly higher treatment success rate than those treated at other institutions (94.1% vs. 69.9%).

CONCLUSIONS

Patients treated with DOT and by pulmonologists, especially at the chest hospital, had a higher treatment success rate. DOT and training of care professionals and institutions are therefore important factors that affect the successful treatment of TB.

The Impact of Arteriovenous Malformation Radiosurgery on the Brain: From Morphology and Perfusion to Neurocognition

The therapeutic aims of brain arteriovenous malformation (AVM) radiosurgery are multiple. Protecting patients from rebleeding is the prime goal. Among the others, hemodynamics, perfusion and neurocognition recovery are interesting and important. Anatomically AVM contains an abnormal cluster of vascular networks (nidus) between arteries and veins. Hemodynamically the nidus contains a low resistance and causes high-flow transnidal shunts between both sides of the nidus. The shunts cause hypotension in the neighboring arteries and diversion of blood from the adjacent brain tissues. The diversion disturbs brain hemodynamics. Radiosurgery, by eliminating the nidus, reconstitutes normal brain hemodynamics. From the early stage after radiosurgery, the abnormal transnidal flows gradually decrease, and the adjacent hemodynamics recovers toward normal. For nonhemorrhagic AVM, improvement of seizure control and stable or improved neurological status are observed clinically. The radiosurgical effects are also reflected in the recovery of metabolism in the adjacent brain and neurocognitive function paralleling the hemodynamic normalization. Morphological cure of AVM and the associated recovery of brain hemodynamics, metabolism and neurocognitive function form the therapeutic rationale of AVM radiosurgery.

CPS1, a homolog of the Streptococcus pneumoniae type 3 polysaccharide synthase gene, is important for the pathobiology of Cryptococcus neoformans

The polysaccharide capsule is known to be the major factor required for the virulence of Cryptococcus neoformans. We have cloned and characterized a gene, designated CPS1, that encodes a protein containing a glycosyltransferase moiety and shares similarity with the type 3 polysaccharide synthase encoded by the cap3B gene of Streptococcus pneumoniae. Cps1p also shares similarity with hyaluronan synthase of higher eukaryotes. Deletion of the CPS1 gene from a serotype D strain of C. neoformans resulted in a slight reduction of the capsule size as observed by using an India ink preparation. The growth at 37 degrees C was impaired, and the ability to associate with human brain endothelial cells in vitro was also significantly reduced by the deletion of CPS1. Using site-specific mutagenesis, we showed that the conserved glycosyltransferase domains are critical for the ability of the strain to grow at elevated temperatures. A hyaluronan enzyme-linked immunosorbent assay method demonstrated that CPS1 is important for the synthesis of hyaluronan or its related polysaccharides in C. neoformans. Comparisons between the wild-type and the cps1Delta strains, using three different transmission electron microscopic methods, indicated that the CPS1 gene product is involved in the composition or maintenance of an electron-dense layer between the outer cell wall and the capsule. These and the virulence studies in a mouse model suggested that the CPS1 gene is important in the pathobiology of C. neoformans.

Similarities and differences for light-induced surface plasmons in one- and two-dimensional symmetrical metallic nanostructures

Two types of double-sided nanostructure, one possessing a slit aperture with parallel grooves and the other possessing a circular aperture with concentric grooves, were fabricated to examine the similarities and differences of their diffraction behavior in one-dimensional (1-D) and two-dimensional (2-D) nanostructures. Based on the projection-slice theory, we conjecture that the surface plasmons in these two different nano-scale grooves possess similar modes. A localized surface plasmon (LSP) was used to examine the transmission characteristics induced by the apertures. The transmission characteristics of the slitted nanostructure and the circular nanostructure aperture were then measured. We coupled the transmission spectra measured from these two apertures with a 1-D parallel groove transmission curve simulated by a 1-D rigorous coupled wave analysis. Measured spectra results show reasonable agreement with the simulated data. We propose that the apparent blueshift observed in the peak frequency of a 2-D nanostructure is due to the difference in the shape of the aperture and the spot transmission characteristics of 1-D and 2-D systems as induced by a LSP.

Systemic Herpes Simplex Virus Infection Following Cadaveric Renal Transplantation: A Case Report

Herpes simplex virus (HSV) infection usually occurs in immunocompromised or severely debilitated patients. It is not so common in patients with renal transplants. The diagnosis can only be made histologically. It usually occurs during or shortly after treatment of graft rejection with high-dose steroids. We have recently experienced a case of HSV esophagitis and nephropathy in the renal allograft biopsy, which was identified by histology, immunostaining, and electron microscopy. A 43-year-old woman underwent cadaveric renal transplantation with cyclosporine and prednisolone treatment. Twelve months later, she developed renal insufficiency and proteinuria. Allograft renal biopsy showed some evidence of acute rejection. She was treated with 3 successive days of methylprednisolone (1.0 g/d) intravenously and continued tapering of steroids. Three weeks after steroid pulse therapy, she had throat pain, oral cavity ulcer, dysphagia, and febrile sensation. Esophagoscopy revealed multiple confluent ulcers in the whole esophagus, and biopsy showed enlarged epithelial cells with prominent nuclei. Immunohistochemically, the epithelial cells were positive with a monoclonal antibody to HSV type 1. She was started on acyclovir intravenously, which was continued for a week. After a week, her symptoms began to improve and repeat endoscopy showed no residual esophagitis. A renal allograft infection with HSV can persist in heavily immunosuppressed patients with recurrent rejection episodes. HSV mainly affects tubular cells causing necrosis, a major reason for functional deterioration. A biopsy is required for diagnosis.

On-Line HPLC-UV/Nano-TiO2-ICPMS System for the Determination of Inorganic Selenium Species

We have developed an UV/nano-TiO2 vapor generation (VG) device that when coupled between a chromatographic column and an ICP mass spectrometer provides a simple and sensitive hyphenated method for the determination of Se(IV) and Se(VI) without the need to use conventional chemical VG techniques. Because our proposed VG device allows both Se(IV) and Se(VI) species in the column effluent to be converted on-line into volatile Se products, which are then measured directly by the ICPMS, the safety risks and the probability of contamination arising from the use of additional chemicals are both low. To achieve the maximum signal intensity, we optimized a number of the operating parameters of the UV/nano-TiO2 VG device, including the acidity, the amounts of TiO2 and formic acid, and the length of the reaction coil, with respect to their effects on the reduction efficiency of the analyte species. This hyphenated method achieves excellent detection limits-0.06 and 0.03 ng mL(-1) for Se(IV) and Se(VI), respectively-because of the high efficiencies of the conversions of Se(IV) and Se(VI) to their respective volatile products and the lower blank level achieved, relative to those of other traditional systems. In addition, because the conversion efficiency of the analyte selenium species reached its maximum level within 36 s of irradiation, the working time (approximately 12 min) was limited primarily by time required for the chromatographic separation. A series of validation experiments-analysis of the 1643e Standard Reference Material and natural water samples-indicated that our proposed methods can be applied satisfactorily to the determination of inorganic selenium species in water samples.

Strategic analysis for sustainable urban river aquatic environment using the system dynamic approach

A sustainable aquatic environment, which relates to the issues of pollution mitigation and ecological restoration, is one of the important indicators of the vitality and prosperity of a city. Traditionally, resort to engineering efforts is always the first priority in dealing with such problems. Nevertheless, treated as an integrated system, the nature of the problem should involve many aspects including economic, ecological, environmental, and engineering factors. Meanwhile, the special feature of the time-dependent state has also made such a system a dynamic and complex problem. The current research has employed the concepts of integrated assessment trying to aggregate related studies and tackling the problem as a complete system. With the aid of the system dynamic modeling tool, which is capable of dealing with dynamic and complex problems, the simulation model was formulated following the macrostructure of system behavior. Various strategies for improving the sustainability of the aquatic environment in Love River, Kaohsiung, Taiwan have been evaluated. The decision makers are therefore allowed to choose more effective strategies based on the integrated perspectives.

DiGeorge syndrome associated with solitary median maxillary central incisor

DiGeorge syndrome is a primary immunodeficiency disease characterized by dysgenesis of the thymus and parathyroid glands, conotruncal cardiac anomalies, and other dysmorphic features. Although most patients have a common microscopic deletion in chromosome 22q11.2, marked clinical variability exists. A solitary median maxillary central incisor (SMMCI) is a rare dental anomaly which may be an isolated occurrence or associated with congenital nasal airway abnormalities or holoprosencephaly. We report a patient with DiGeorge syndrome who was diagnosed at nearly 1 month of age and was later found to have a solitary median central incisor. Initially, the patient presented with recurrent episodes of respiratory distress attributed to partial airway obstruction, one of the phenotypic features of SMMCI. A fluorescence in situ hybridization study showed a chromosome 22q11.2 deletion.

Transcription factor decoy for AP-1 reduces mesangial cell proliferation and extracellular matrix production in vitro and in vivo

Diabetic nephropathy is characterized by an expansion of glomerular mesangium, caused by mesangial cell proliferation and excessive accumulation of extracellular matrix (ECM) proteins, which eventually leads to glomerulosclerosis and renal failure. Activator protein-1 (AP-1), a transcription factor, is implicated in the transcriptional regulation of a wide range of genes participating in cell proliferation and ECM production. This investigation was undertaken to test the hypothesis that AP-1 plays an important role in ECM gene expression, and to develop a molecular therapeutic strategy based on decoy oligodeoxynucleotides (ODN). In this report, we show that transfection with AP-1 decoy ODN strongly inhibits high glucose- and angiotensin II-induced cell proliferation and expression of ECM genes in cultured mesangial cells in vitro. Administration of AP-1 decoy ODN into streptozotocin-induced diabetic rat kidney in vivo using the hemagglutinating virus of Japan (HVJ)-liposome method virtually abolished TGF-beta1 and plasminogen activator inhibitor-1 expression. Our results collectively indicate that AP-1 activation is crucial for mesangial cell proliferation and ECM production in response to high glucose and angiotensin II. Moreover, use of stable AP-1 decoy ODN combined with the highly effective HVJ-liposome method provides a novel potential molecular therapeutic strategy for the prevention of diabetic nephropathy.

Haploid fruiting in Cryptococcus neoformans is not mating type alpha-specific

Under appropriate conditions, haploid Cryptococcus neoformans cells can undergo a morphological switch from a budding yeast form to develop hyphae and viable basidiospores, which resemble those produced by mating. This process, known as haploid fruiting, was previously thought to occur only in MATalpha strains. We identified two new strains of C. neoformans var. neoformans serotype D that are MATa type and are able to haploid fruit. Further, a MATa reference strain, B-3502, also produced hyphae and fruited after prolonged incubation on filament agar. Over-expression of STE12a dramatically enhanced the ability of all MATa strains tested to filament. Segregation analysis of haploid fruiting ability confirmed that haploid fruiting is not MATalpha-specific. Our results indicate that MATa cells are intrinsically able to haploid fruit and previous observations that they do not were probably biased by the examination of a small number of genetically related isolates that have been maintained in the laboratory for many years.

Striatal formation of 6-hydroxydopamine in mice treated with pargyline, pyrogallol and methamphetamine

Formation of 6-hydroxydopamine (6-OHDA) has been posited in the striatum following methamphetamine treatment and plays a critical role in methamphetamine-induced nigrostriatal dopaminergic toxicity. We used high performance liquid chromatography electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS) to determine the formation of 6-OHDA by the treatments of methamphetamine combined with pargyline, a monoamine oxidase inhibitor, and pyrogallol, a catechol-O-methyl-transferase inhibitor, in female C57BL/6J mouse striatum. A substantial amount of 6-OHDA (9.9 +/- 0.7 pg/mg wet tissue) was detected in mice treated with pargyline (100 mg/kg) and pyrogallol (25 mg/kg) in combination. Greater striatal 6-OHDA levels were observed in mice treated with combined pargyline, pyrogallol and methamphetamine (50 mg/kg) as compared to mice treated with combined pargyline and pyrogallol. However, mice treated with pargyline and pyragollol in combination followed by one and two doses of methamphetamine exhibited comparable striatal 6-OHDA levels (23.2 +/- 4.3, 27.3 +/- 1.3 pg/mg wet tissue) in our protocol. We conclude that blockade of the primary metabolic pathways of dopamine by inhibiting both monoamine oxidase and catechol-O-methyl-transferase activities is sufficient to induce 6-OHDA formation in the striatum. Acute 6-OHDA accumulation in the striatum can be potentiated by methamphetamine, a potent dopamine releaser, administration following such metabolic inhibitions.

Adaptive phase field simulation of dendritic growth in a forced flow at various supercoolings

An efficient finite volume method is developed for the phase-field simulation of two-dimensional dendritic growth in a forced flow at various supercoolings. The adaptive nature of the method allows the dendrite in a large domain to evolve secondary structures, even at low supercoolings. In addition to good agreement with previous calculations on the tip shape and speed, the effects of forced flow at various supercoolings are investigated and compared with the Oseen-Ivantsov solution and good agreement is found. The steady dendrite shape in all cases continues to have a self-affine nature and the invariant scaling parameters are in good agreement with the estimation.

The design of a web-based decision support system for the sustainable management of an urban river system

The effects of urbanization on the aquatic environment, and solutions to the deterioration of water quality and stream ecology in the Love River have long been the main focus of environmental management in southern Taiwan. Apart from choosing the regular strategies of installing an intercept and sewer system, coastal wastewater treatment plant, and ocean outfall pipe, a new opportunity for improving the overall managerial efficiency is to design and implement a web-based Decision Support System (DSS). This DSS must be capable of managing storm water impacts when overflow is inevitable, river water quality variations loading to influences on the ecosystem, and changing land use programs along river corridors and adjacent urban areas simultaneously. This paper presents a new design framework for building such a DSS. By using the advanced information technology in the "Internet" environment, the proposed DSS may perform normal queries and statistical analyses in a web-enabled database, spatial analysis via the use of a Geographic Information System (GIS) in the Internet environment, and essential data warehousing/data mining. Possible linkage with various analytical models is anticipated. Such a DSS must be helpful for achieving the rehabilitation of the estuarine ecosystem and satisfying the goals for sustainable management in a regional sense.

The relationship between FTL and NA, DMV or CVLM in central cardiovascular control

The aim of the present study was to examine the relationship between the lateral tegmental field (FTL), a cardioinhibitory area, with other cardioinhibitory areas, i.e., the ambiguus nucleus (NA) and the dorsal motor nucleus of vagus (DMV) and the caudal ventrolateral medulla (CVLM), a vasopressor inhibitory area. In 55 cats anesthetized with chloralose (40 mg/kg) and urethane (400 mg/kg), the cardiovascular responses of heart rate (HR), systemic arterial blood pressure (SAP) and vertebral nerve activity (VNA) were recorded. The FTL, NA, DMV and CVLM were identified first by stimulation (rectangular pulses in 80 Hz, 0.5 ms, 50-100 microA) and then confirmed by microinjection of sodium glutamate (Glu, 0.25M, 70 nl). In studying the influence of NA, DMV, or CVLM lesion on the Gluinduced responses in FTL, kainic acid (KA, 24 mM, 100 nl) was microinjected into the NA, DMV or CVLM. FTL stimulation produced an average decrease of HR by 55%. After KA lesioning of the ipsilateral NA or the DMV, the decreased HR induced by FTL was significantly diminished. After subsequent lesion of the contralateral DMV or NA, the bradycardia of FTL was abolished. The reduction of resting HR was more intense after lesioning the NA than DMV and with the left side more than that of the right side. These studies suggest that the cardioinhibitory responses of FTL are mediated through both NA and DMV with predominance of the former, while the hypotensive effect of FTL is mediated through CVLM. The precise pathway responsible for the FTL-induced bradycardia and hypotension is to be determined.