Frequency Variation of Ventricular Fibrillation May Help Predict Successful Defibrillation in a Rat Model of Cardiac Arrest

BACKGROUND

To evaluate whether the frequency variation of ventricular fibrillation (VF) helps to predict successful defibrillation in a rat model of cardiac arrest.

METHODS

VF was induced in rats followed by cardiopulmonary resuscitation and then defibrillation. The electrocardiographic signals of 30 rats with first-shock success were obtained from our previous animal experiments, and 300 rats without first-shock success were selected as control. The VF waveform immediately before the first defibrillation was analyzed.

RESULTS

Eighty-eight percentages of the frequency variations of an electrocardiogram (ECG) record falling in the range -9.5-9.5 Hz was selected with sensitivity of 0.8, specificity of 0.583, and area under curve (AUC) of 0.708. Compared with amplitude spectrum area (AMSA) (sensitivity = 0.767, specificity= 0.547, and AUC = 0.678), combining frequency variation and AMSA significantly increases the predictability with sensitivity of 0.933, specificity of 0.493, and AUC of 0.732 (p = 0.005).

CONCLUSIONS

The frequency variation of VF may serve a useful parameter to predict defibrillation success.

Novel non-contact control system of electric bed for medical healthcare

A novel non-contact controller of the electric bed for medical healthcare was proposed in this study. Nowadays, the electric beds are widely used for hospitals and home-care, and the conventional control method of the electric beds usually involves in the manual operation. However, it is more difficult for the disabled and bedridden patients, who might totally depend on others, to operate the conventional electric beds by themselves. Different from the current controlling method, the proposed system provides a new concept of controlling the electric bed via visual stimuli, without manual operation. The disabled patients could operate the electric bed by focusing on the control icons of a visual stimulus tablet in the proposed system. Besides, a wearable and wireless EEG acquisition module was also implemented to monitor the EEG signals of patients. The experimental results showed that the proposed system successfully measured and extracted the EEG features related to visual stimuli, and the disabled patients could operate the adjustable function of the electric bed by themselves to effectively reduce the long-term care burden.

A Wearable Channel Selection-Based Brain-Computer Interface for Motor Imagery Detection

Motor imagery-based brain-computer interface (BCI) is a communication interface between an external machine and the brain. Many kinds of spatial filters are used in BCIs to enhance the electroencephalography (EEG) features related to motor imagery. The approach of channel selection, developed to reserve meaningful EEG channels, is also an important technique for the development of BCIs. However, current BCI systems require a conventional EEG machine and EEG electrodes with conductive gel to acquire multi-channel EEG signals and then transmit these EEG signals to the back-end computer to perform the approach of channel selection. This reduces the convenience of use in daily life and increases the limitations of BCI applications. In order to improve the above issues, a novel wearable channel selection-based brain-computer interface is proposed. Here, retractable comb-shaped active dry electrodes are designed to measure the EEG signals on a hairy site, without conductive gel. By the design of analog CAR spatial filters and the firmware of EEG acquisition module, the function of spatial filters could be performed without any calculation, and channel selection could be performed in the front-end device to improve the practicability of detecting motor imagery in the wearable EEG device directly or in commercial mobile phones or tablets, which may have relatively low system specifications. Finally, the performance of the proposed BCI is investigated, and the experimental results show that the proposed system is a good wearable BCI system prototype.

Design of novel non-contact multimedia controller for disability by using visual stimulus

The design of a novel non-contact multimedia controller is proposed in this study. Nowadays, multimedia controllers are generally used by patients and nursing assistants in the hospital. Conventional multimedia controllers usually involve in manual operation or other physical movements. However, it is more difficult for the disabled patients to operate the conventional multimedia controller by themselves; they might totally depend on others. Different from other multimedia controllers, the proposed system provides a novel concept of controlling multimedia via visual stimuli, without manual operation. The disabled patients can easily operate the proposed multimedia system by focusing on the control icons of a visual stimulus device, where a commercial tablet is used as the visual stimulus device. Moreover, a wearable and wireless electroencephalogram (EEG) acquisition device is also designed and implemented to easily monitor the user's EEG signals in daily life. Finally, the proposed system has been validated. The experimental result shows that the proposed system can effectively measure and extract the EEG feature related to visual stimuli, and its information transfer rate is also good. Therefore, the proposed non-contact multimedia controller exactly provides a good prototype of novel multimedia controlling scheme.

The difference in myocardial injuries and mitochondrial damages between asphyxial and ventricular fibrillation cardiac arrests

INTRODUCTION

Ventricular fibrillation (VF) and asphyxia account for most cardiac arrests but differ in cardiac arrest course, neurologic deficit, and myocardial damage. In VF resuscitation, cardiac mitochondria were known to be damaged via excess generation of reactive oxygen species. This study evaluated the difference of cardiac mitochondrial damages between VF and asphyxial cardiac arrests.

METHODS

In the VF + electrical shock (ES) group, VF was induced and untreated for 5 minutes, followed by 1 minute of cardiopulmonary resuscitation (CPR) and 1 ES of 5 J. Animals were killed immediately after ES. In the asphyxia group, cardiac arrest was induced by airway obstruction, and then pulselessness was maintained for 5 minutes, followed by 1 minute of CPR. The animals were killed immediately after CPR. The histology and ultrastructural changes of myocardium and complex activities and respiration of mitochondria were evaluated. The mitochondrial permeability transition pore opening was measured based on mitochondrial swelling rate.

RESULTS

The histopathologic examinations showed myocardial necrosis and mitochondrial damage in both cardiac arrests. Instead of regional damages of myocardium in the VF + ES group, the myocardial injury in the asphyxia group distributed diffusely. The asphyxia group demonstrated more severe mitochondrial damage than the VF + ES group, which had a faster mitochondrial swelling rate, more decreased cytochrome c oxidase activity, and more impaired respiration.

CONCLUSIONS

Both VF and asphyxial cardiac arrests caused myocardial injuries and mitochondrial damages. Asphyxial cardiac arrest presented more diffuse myocardial injuries and more severe mitochondrial damages than VF cardiac arrest.

Idiopathic syringomyelia: case report and review of the literature

Syringomyelia is an uncommon disease that is caused most often by type I Chiari malformation, which develops in the hindbrain, and less frequently by other factors which are not limited to the hindbrain, including trauma, infection, or scoliosis. Idiopathic syringomyelia is rare. We present in this article a patient with idiopathic syringomyelia characterized by hypoesthesia and progressive weakness in the left lower limb. Decompression was attempted by means of laminectomy and a syringoarachnoid shunt. Motor, sensory, and bladder functions were monitored by the change in Japanese Orthopedic Association scores, which increased from 10 points preoperatively to 14 points 30 days postoperatively. This case demonstrates the effectiveness of surgical decompression in a patient with remarkable neurological deficit.

Microfluidic Flow Switching Design Using Volume of Fluid Model

In this study, a volume of fluid (VOF) model was employed for microfluidic switch design. The VOF model validity in predicting the interface between fluid streams with different viscosities co-flowing in a microchannel was first verified by experimental observation. It was then extended to microfluidic flow switch design. Two specific flow switches, one with a guided fluid to one of five desired outlet ports, and another with a guided fluid flows into one, two, or three outlet ports equally distributed along the outlet channel of a Y-shaped channel. The flow switching was achieved by controlling the flow rate ratios between tested and buffer fluids. The numerical results showed that the VOF model could successfully predict the flow switching phenomena in these flow switches. The numerical results also showed that the flow rate ratio required for flow switching depends on the viscosity ratio between the tested and buffer fluids. The numerical simulation was verified by experimental study and the agreement was good.

Stenotrophomonas maltophilia septicemia with pyomyositis in a chemotherapy-treated patient

Pyomyositis is a rare complication of chemotherapy. A 35-year-old male patient with myelodysplastic syndrome developed Stenotrophomonas maltophilia bacteremia shortly after chemotherapy, and Stenotrophomonas maltophilia-related pyomyositis was encountered after recovery from neutropenia. He recovered completely after surgical drainage and a protracted course of antibiotic treatment. It is postulated that subclinical myopathy, immunosuppression secondary to the malignancy, or chemotherapeutic drugs may predispose to pyomyositis. Early recognition of this unusual complication in a cancer patient undergoing chemotherapy can prevent further catastrophes.

Inhibition of melanoma growth and metastasis by combination with (-)-epigallocatechin-3-gallate and dacarbazine in mice

(-)-Epigallocatechin-3-gallate (EGCG), a major polyphenol in green tea, was shown to have cancer chemopreventive activity. In this study, we examined the antimetastatic effects of EGCG or the combination of EGCG and dacarbazine on B16-F3m melanoma cells in vitro and in vivo. First, the antimetastatic potentials of five green tea catechins were examined by soft agar colony formation assay, and the results show that EGCG was more effective than the other catechins in inhibiting soft agar colony formation. Second, EGCG dose-dependently inhibited B16-F3m cell migration and invasion by in vitro Transwell assay. Third, EGCG significantly inhibited the spread of B16-F3m cells on fibronectin, laminin, collagen, and Matrigel in a dose-dependent manner. In addition, EGCG significantly inhibited the tyrosine phosphorylation of focal adhesion kinase (FAK) and the activity of matrix metalloproteinase-9 (MMP-9). In animal experiments, EGCG alone reduced lung metastases in mice bearing B16-F3m melanomas. However, a combination of EGCG and dacarbazine was more effective than EGCG alone in reducing the number of pulmonary metastases and primary tumor growths, and increased the survival rate of melanoma-bearing mice. These results demonstrate that combination treatment with EGCG and dacarbazine strongly inhibits melanoma growth and metastasis, and the action mechanisms of EGCG are associated with the inhibition of cell spreading, cell-extracellular matrix and cell-cell interactions, MMP-9 and FAK activities.

A preliminary study on electrically enhanced crossflow microfiltration of CMP (chemical-mechanical polishing) wastewater

Chemical-mechanical polishing (CMP) is currently one of the main technologies used by wafer plants in the semiconductor industry. Normally, a large amount of de-ionized water should be used to wash out the abrasives adhered to the surface of wafers during the grinding process. Therefore, CMP wastewater not only has a great quantity but also contains very small size of suspended solids. Generally, these suspended solids would not settle. This phenomenon results in a low visibility of CMP wastewater. To solve this problem, a study on electrically enhanced crossflow microfiltration of CMP wastewater was conducted. Normally, the membrane of traditional dead-end filtration is easily blocked by the filter cake resulting in a small flux of filtrate. Therefore, the form of crossflow filtration (CFF) is used to reduce the blocking of the membrane. Furthermore, if CFF is accompanied by an external electric field, the negatively charged suspended solids in wastewater would move toward the positive electrode. Meanwhile, the flux of filtrate would increase. In this investigation, CMP wastewater was obtained from a wafer plant and characterized by various standard methods. Before testing, the CMP wastewater was pre-filtered using a 1.2 microm pore size filter. Then it was operated by a crossflow microfiltration (0.1 microm pore size) system under an appropriate crossflow velocity, filtration pressure, and electric potential. The filtrate was also characterized by various standard methods. Experimental results show that the filtrate has a turbidity of zero value. Thus, the filtrate could be reused for other purposes. However, the suspended solids of the CMP wastewater would be concentrated by this method. Therefore, the recovery of the suspended solids would be worth considering.

Outbreak of infection with multidrug-resistant Klebsiella pneumoniae carrying bla(IMP-8) in a university medical center in Taiwan

Klebsiella pneumoniae strains with the transferable carbapenem-hydrolyzing metallo-beta-lactamases, which include IMP- and VIM-type enzymes, remain extremely rare. To investigate whether IMP- or VIM-producing K. pneumoniae isolates had spread at a university medical center in Taiwan, a total of 3,458 clinical isolates of K. pneumoniae consecutively collected in 1999 and 2000 were tested by the agar diffusion method, colony hybridization, PCR, and nucleotide sequencing. A total of 40 isolates (1.2%), or 17 nonrepetitive isolates, from 16 patients were found to carry bla(IMP-8), a metallo-beta-lactamase gene recently identified from a K. pneumoniae strain in Taiwan. Carriage of bla(VIM) or other bla(IMP) genes was detected in none of the remaining isolates. Of the 17 nonrepetitive bla(IMP-8)-positive isolates, 15 isolates (88.2%) appeared susceptible to imipenem (MICs, <or=4 microg/ml) and meropenem (MICs, <or=1 microg/ml), indicating the difficulty in detecting bla(IMP-8) in K. pneumoniae by routine susceptibility tests; 14 isolates (82.4%) produced SHV-12 as well; and 14 isolates (82.4%) were also resistant to fluoroquinolones. The organisms caused wound infections in eight patients and bloodstream infections in three patients. They were not directly associated with the death of nine patients. Before the recovery of the bla(IMP-8)-positive isolates, all 16 patients had undergone various surgical procedures, and 15 patients had been admitted to the surgical intensive care unit, suggesting a nosocomial outbreak. Two major patterns were observed by pulsed-field gel electrophoresis for 14 of the 17 nonrepetitive isolates, indicating that the clonal spread was mainly responsible for the outbreak.

Results of 12-year clinical study of giant retinal tear

BACKGROUND

To evaluate the surgical results of scleral buckling alone on eyes with retinal detachment with giant retinal tears of less than 120 degrees, without inverted flap or proliferative vitreoretinopathy, and vitrectomy combined with scleral buckling with or without intraoperative usage of perfluorocarbon liquid (PFCL) in complicated cases.

METHODS

Retrospectively, we reviewed giant retinal tear cases treated at Chang Gung Memorial Hospital, Kaohsiung, Taiwan between January 1, 1989 and August 31,2000. The surgical techniques consisted of standard three-port pars plana vitrectomy combined with scleral buckling in complicated cases, PFCL used intraoperatively in later cases, and scleral buckling alone in minor cases.

RESULTS

A total of 47 consecutive eyes with giant retinal tears with retinal detachment in 45 patients with no previous history of ocular penetrating injury or vitreoretinal operations were enrolled in this study. The follow-up period was at least three months for all patients. Thirty-four eyes (72.3%) had giant retinal tears of less than 180 degrees, 12 eyes (25.5%) had tears between 180 degrees and 270 degrees, and one eye had two giant retinal tears. Scleral buckling combined with vitrectomy was performed in 36 complicated eyes (76.6%), PFCL was used intraoperatively later in 24 eyes, and scleral buckling was used alone in 11 minor cases (23.4%). Thirty eyes (63.8%) gained reattachment after the first surgery. Altogether, the retinas of 38 of 47 eyes (80.9%) remained attached at the last follow-up examination.

CONCLUSION

In minor cases of giant retinal tear, scleral buckling alone without vitrectomy may be considered the primary surgical procedure. In complicated cases, using PFCL intraoperatively not only affords many advantages during surgery, but also raises the retinal reattachment rate.

QT interval effects of cisapride in the clinical setting

PURPOSE

The clinical effect of cisapride on QT intervals was prospectively studied.

SUBJECTS

Consecutive adult patients were recruited in whom cisapride was indicated for gastroesophogeal reflux, gastric ulcer, duodenal ulcer, diabetic gastroparesis or chronic constipation refractory to laxatives. Exclusion criteria included disorders and medications affecting cardiac conduction, electrolyte homeostasis, drug clearance and membrane stability.

METHODS

Seventy-five patients were included and followed at 1 to 2 week intervals. Patients took cisapride 5 mg thrice daily for 1 to 4 weeks (lower dose stage), followed by 10 mg thrice daily for another 1 to 4 weeks (higher dose stage). Twelve-lead ECGs were performed before commencing cisapride (group B), at completion of the lower dose stage (group L) and at completion of the higher dose stage (group H).

RESULTS

No patients experienced presyncope or syncope. Seventeen patients failing to comply, and 7 complaining of abdominal discomfort or diarrhea were excluded, leaving 51 participants. Group H's corrected QT interval (QTc) was longer than group B's by 13+/-15 ms (P<0.001), and longer than group L's by 7+/-11 ms (P<0.001). Group L's QTc was longer than group B's by 7+/-21 ms (P<0.05). QT dispersion did not differ significantly among groups. Neither torsade de pointe nor ventricular tachycardia were noted in Holter monitoring of 33 patients during the higher dose stage.

CONCLUSION

cisapride dose-dependently prolongs the QT interval. Further study is needed to examine the arrhythmogenicity of cisapride in higher doses and for longer durations.

Suppression of Fas ligand expression on endothelial cells by arsenite through reactive oxygen species

Chronic exposure to arsenite is associated with vascular disease, such as arteriosclerosis. However, the cellular mechanisms for vascular disease in response to arsenic are not well known. The present study has demonstrated that arsenite not arsenate decreased the Fas ligand (FasL) expression on ECV304 cells through reactive oxygen species. Incubation of ECV304 cells with arsenite decreased the FasL expression and increased the intracellular peroxide levels. In addition, hydrogen peroxide was found to suppress FasL expression in a dose-dependent manner. The antioxidant, N-acetyl-cysteine, blocked the suppression of FasL expression in response to arsenite. These data suggested that arsenite initiates endothelium dysfunction, at least partly, by suppressing the FasL expression through activating reactive oxygen species sensitive endothelial cell signaling.

Choroidal masses: a fourteen-year analysis

BACKGROUND

Choroidal masses present much diversification in clinical features and incidence. The purpose of this study is to investigate the epidemiological and clinicopathological manifestations of different choroidal tumors in order to tabulate appropriate diagnostic approaches.

METHODS

A retrospective analysis of patients with choroidal masses was conducted, the analysis being based upon the review of our medical records from January 1986 to December 1999 inclusively. A definite diagnosis of choroidal mass was confirmed by at least two experienced ophthalmologists. For patients who were enrolled in this study, an ophthalmic examination was conducted and medical history was recorded. Some ancillary tests, such as indirect ophthalmoscopy, ultrasonography, fluorescein angiography, computed tomography, and magnetic resonance imaging, were used to support the accuracy of our diagnoses.

RESULTS

A total of 149 patients were enrolled in this study, of which 103 cases were excluded due to a loss of follow-up or incomplete medical records. Forty-six patients (51 eyes) included 12 cases (26%) of malignant metastases, 10 cases (22%) of hemangiomas, 2 cases (4%) of osteomas, 5 cases (11%) of melanocytomas, 8 cases (17%) of melanomas, and 9 cases (20%) of other melanocytic lesions. The male to female ratio was 21:25. The average length of follow-up was 20.5 months, and the average age of these patients was 42.8 years. Presenting with varied clinical incidence and pictures, each category of choroidal mass was investigated thoroughly.

CONCLUSION

With more clinical experience and a better understanding of choroidal masses, we are able to propose an early differential diagnosis and therapeutic approach to the effective management of them in order to minimize ocular morbidity and improve patients' survival and quality of life.

Metallo-beta-lactamases in clinical Pseudomonas isolates in Taiwan and identification of VIM-3, a novel variant of the VIM-2 enzyme

A total of 209 clinical isolates of Pseudomonas (193 Pseudomonas aeruginosa, 10 P. putida, 4 P. stutzeri, and 2 P. fluorescens isolates) with reduced susceptibilities to imipenem and/or ceftazidime were subjected to PCR assays with primers specific for bla(IMP-1), bla(IMP-2), bla(VIM-1), and bla(VIM-2) and sequence analysis to identify the metallo-beta-lactamases (MBLs) prevalent among these organisms in Taiwan; and 21 isolates gave positive results. Five isolates including two P. putida and three P. stutzeri isolates were found to carry bla(IMP-1), and six isolates including five P. putida and one P. stutzeri isolates harbored bla(VIM-2). The remaining 10 isolates were P. aeruginosa, and all were found to carry a novel variant of bla(VIM-2), designated bla(VIM-3). There are only two nucleotide differences between bla(VIM-2) and bla(VIM-3), leading to two amino acid alterations. Our findings indicate that VIM-2 and its variant have become the most prevalent metalloenzymes in Pseudomonas in Taiwan. Southern hybridization with the bla(VIM-2)-, bla(VIM-3)-, and bla(IMP-1 )-specific probes revealed that only two VIM-2-producing P. putida isolates appeared to carry the MBL gene on plasmids. Pulsed-field gel electrophoresis showed that six VIM-3-producing P. aeruginosa isolates and two IMP-1-producing P. stutzeri isolates were genetically related, suggesting that the spread of these MBL genes in Taiwan could be due to clonal dissemination as well as genetic exchange between different clones.

Suppression of inducible cyclooxygenase and nitric oxide synthase through activation of peroxisome proliferator-activated receptor-gamma by flavonoids in mouse macrophages

Peroxisome proliferator-activated receptor (PPAR)gamma transcription factor has been implicated in anti-inflammatory response. Of the compounds tested, apigenin, chrysin, and kaempferol significantly stimulated PPAR gamma transcriptional activity in a transient reporter assay. In addition, these three flavonoids strongly enhanced the inhibition of inducible cyclooxygenase and inducible nitric oxide synthase promoter activities in lipopolysaccharide-activated macrophages which contain the PPAR gamma expression plasmids. However, these three flavonoids exhibited weak PPAR gamma agonist activities in an in vitro competitive binding assay. Limited protease digestion of PPAR gamma suggested these three flavonoids produced a conformational change in PPAR gamma and the conformation differs in the receptor bound to BRL49653 versus these three flavonoids. These results suggested that these three flavonoids might act as allosteric effectors and were able to bind to PPAR gamma and activate it, but its binding site might be different from the natural ligand BRL49653.

Alternative activation of extracellular signal-regulated protein kinases in curcumin and arsenite-induced HSP70 gene expression in human colorectal carcinoma cells

We have investigated the regulation mechanism of chemical stress-induced HSP70 gene expression in human colorectal carcinoma cells (COLO205 and HT29). Our data show that chemical treatments including sodium arsenite and curcumin, induced significant synthesis of HSP70 and its mRNA. The induced HSP70 gene expression appears to be increased at the transcriptional level. The increase in HSP70 gene expression by both chemicals is associated with an increase in HSF binding to HSE and induction of HSF1 di- or trimerization. Phosphorylation and activation of extracellular signal-regulated proteins (ERK1/2) were detected in sodium arsenite-treated COLO205 and HT29 cells, and the free radical scavenger N-acetyl-L-cysteine (NAC) was able to inhibit this ERK1/2 activation and HSP70 gene expression. MAPK blockade by the specific MEK1 inhibitor (PD98059) decreased the ability of sodium arsenite to increase HSP70 gene expression in a dose-dependent manner along with dephosphorylation of ERK1/2 proteins. In contrast to arsenite treatment, activation of ERK1/2 was not detected in curcumin-treated colorectal carcinoma cells, and NAC and PD98059 did not show any inhibitory effect on HSP70 gene expression induced by curcumin. Overexpression of a dominant negative mutant of mitogen-activated protein kinase kinase kinase 1 (MEKK1-DN) prevents arsenite-induced ERK1/2 phosphorylation and HSP70 protein synthesis. These results indicated that the ERK signaling pathway can participate in HSP70 gene expression induced by the prooxidant sodium arsenite, but not by the antioxidant curcumin.

Dissemination of CTX-M-3 and CMY-2 beta-lactamases among clinical isolates of Escherichia coli in southern Taiwan

A total of 1,210 clinical isolates of Escherichia coli collected from a university hospital in southern Taiwan were screened for production of extended-spectrum beta-lactamases (ESBLs). Expression of classical ESBLs (resistant to extended-spectrum beta-lactam agents and susceptible to beta-lactam inhibitors) was inferred in 18 isolates by the phenotypic confirmatory test. These included 10 isolates producing CTX-M-3, 2 strains carrying SHV-12, 1 strain harboring SHV-5, 1 strain expressing TEM-10, and 4 strains producing unidentifiable ESBLs with a pI of 8.05, 8.0, or 7.4. Eighteen isolates that showed decreased susceptibilities to ceftazidime and/or cefotaxime, negative results for the confirmatory test, and high-level resistance to cefoxitin (MICs of >/=128 microg/ml) were also investigated. Five isolates were found to produce CMY-2 AmpC enzymes, one isolate carried both CTX-M-3 and CMY-2, and the remaining three and nine isolates expressed putative AmpC beta-lactamases with pIs of >9.0 and 8.9, respectively. Thus, together with the isolate producing CTX-M-3 and CMY-2, 19 (1.6%) isolates produced classical ESBLs. Pulsed-field gel electrophoresis revealed that all isolates carrying CTX-M-3 and/or CMY-2 were genetically unrelated, indicating that dissemination of resistance plasmids was responsible for the spread of these two enzymes among E. coli in this area. Among the 16 isolates expressing CTX-M-3 and/or CMY-2, 5 might have colonized outside the hospital environment. Our data indicate that CTX-M-3 and CMY-2, two beta-lactamases initially identified in Europe, have been disseminated to and are prevalent in Taiwan.

Prevalence of SHV-12 among clinical isolates of Klebsiella pneumoniae producing extended-spectrum beta-lactamases and identification of a novel AmpC enzyme (CMY-8) in Southern Taiwan

Twenty (8.5%) of 234 nonrepetitive clinical isolates of Klebsiella pneumoniae from southern Taiwan were found to produce extended-spectrum beta-lactamases (ESBLs): 10 strains produced SHV-12, 4 produced SHV-5, 2 produced a non-TEM non-SHV ESBL with a pI of 8.3, 3 produced a novel AmpC beta-lactamase designated CMY-8 with a pI of 8.25, and 1 produced SHV-12 and an unidentified AmpC enzyme with a pI of 8.2. The CMY-8 enzyme confers a resistance phenotype similar to CMY-1 and MOX-1, and sequence comparisons showed high homologies (>95%) of nucleotide and amino acid sequences among these three enzymes. Plasmid and pulse-field gel electrophoresis analyses revealed that all isolates harboring an SHV-derived ESBL were genetically unrelated, indicating that dissemination of resistance plasmids is responsible for the spread of SHV ESBLs among K. pneumoniae in this area. All three isolates carrying CMY-8 had identical genotypic patterns, suggesting the presence of an epidemic strain.

Comparison of the MB/BacT and BACTEC MGIT 960 system for recovery of mycobacteria from clinical specimens

A total of 543 specimens were cultured in parallel with the MB/BacT and BACTEC MGIT 960 systems and on the conventional solid media. Mycobacteria were identified from 95 (17.5%) specimens, including 63 (66.3%) Mycobacterium tuberculosis and 32 (33.7%) nontuberculous mycobacteria. The recovery rates for the MB/BacT, MGIT 960, and solid media were 91.6, 87.4, and 54.7%, respectively, for all mycobacteria; the recovery rates were 93.6, 88.9, and 63.4%, respectively, for M. tuberculosis complex alone, and 87.5, 84.4, and 37.5%, respectively, for all nontuberculous mycobacteria. The mean times to detection of all mycobacteria by individual systems were 13. 9, 8.7, 31.7 days for the MB/BacT, MGIT 960 and solid media, respectively, 13.9, 9.3, 32.9 days for M. tuberculosis alone, and 14. 1, 8.1, 27.2 days for all nontuberculous mycobacteria. The contamination rates of the MB/BacT and MGIT 960 were 10.2 and 5.4%, respectively. With regard to detection times and recovery rates, both automated systems are superior to the conventional media (all p < 0.005). As compared to the MB/BacT, the MGIT 960 detected mycobacterial growth more rapidly (p < 0.001), and had a lower contamination rate (p = 0.003); however, there was no statistically significant difference in recovery rates between these two systems. These results indicate that both MGIT 960 and MB/BacT systems are rapid, sensitive, and efficient methods for the recovery of mycobacteria from clinical specimens.

Ground-state degeneracy of Potts antiferromagnets on two-dimensional lattices: approach using infinite cyclic strip graphs

The q-state Potts antiferromagnet on a lattice Lambda exhibits nonzero ground-state entropy S0=kB ln W for sufficiently large q and hence is an exception to the third law of thermodynamics. An outstanding challenge has been the calculation of W(sq,q) on the square (sq) lattice. We present here an exact calculation of W on an infinite-length cyclic strip of the square lattice, which embodies the expected analytic properties of W(sq,q). Similar results are given for the kagomé lattice.

Suppression of inducible cyclooxygenase and inducible nitric oxide synthase by apigenin and related flavonoids in mouse macrophages

Prostaglandins biosynthesis and nitric oxide production have been implicated in the process of carcinogenesis and inflammation. In this study, we investigated the effect of various flavonoids and (-)-epigallocatechin-3-gallate on the activities of inducible cyclooxygenase (COX-2) and inducible nitric oxide synthase (iNOS) in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages. Apigenin, genistein and kaempferol were markedly active inhibitors of transcriptional activation of COX-2, with IC(50) < 15 microM. In addition, apigenin and kaempferol were also markedly active inhibitors of transcriptional activation of iNOS, with IC(50) < 15 microM. Of those compounds tested, apigenin was the most potent inhibitor of transcriptional activation of both COX-2 and iNOS. Western and northern blot analyses demonstrated that apigenin significantly blocked protein and mRNA expression of COX-2 and iNOS in LPS-activated macrophages. Transient transfection experiments showed that LPS caused an approximately 4-fold increase in both COX-2 and iNOS promoter activities, these increments were suppressed by apigenin. Moreover, electrophoretic mobility shift assay (EMSA) experiments indicated that apigenin blocked the LPS-induced activation of nuclear factor-kB (NF-kB). The inhibition of NF-kB activation occurs through the prevention of inhibitor kB (IkB) degradation. Transient transfection experiments also showed that apigenin inhibited NF-kB-dependent transcriptional activity. Finally, we showed that apigenin could inhibit the IkB kinase activity induced by LPS or interferon-gamma. The results of further studies suggest that suppression of transcriptional activation of COX-2 and iNOS by apigenin might mainly be mediated through inhibition of IkB kinase activity. This study suggests that modulation of COX-2 and iNOS by apigenin and related flavonoids may be important in the prevention of carcinogenesis and inflammation.

Suppression of TNFalpha-mediated NFkappaB activity by myricetin and other flavonoids through downregulating the activity of IKK in ECV304 cells

Flavonoids are a group of naturally-occurring phenolic compounds in the plant kingdom, and many flavonoids are found with vascular protective properties. Nevertheless how the protective response is exerted by flavonoids is not well characterized. In view of the nuclear factor-kappaB (NFkappaB) may play a central role in the initiation of atherosclerosis, prevention of the activation of NFkappaB represents an important role in protecting vascular injury. In this study, the effects of flavonoids on NFkappaB/inhibitor-kappaB (IkappaB) system in ECV304 cells activated with tumor necrosis factor-alpha (TNFalpha) were examined. We investigated the inhibitory action of six flavonoids on IkappaB kinase (IKK) activity, an enzyme recently found to phosphorylate critical serine residues of IkappaB for degradation. Of six flavonoids tested, myricetin was found to strongly inhibit IKK kinase activity, and prevent the degradation of IkappaBalpha and IkappaBbeta in activated endothelial cells. Furthermore, myricetin was also found to inhibit NFkappaB activity correlated with suppression of monocyte adhesion to ECV304 cells. Therefore we conclude that flavonoids may be of therapeutic value for vascular disease through down regulation of NFkappaB/IkappaB system.

Chemoprevention of cancer and cardiovascular disease by resveratrol

Resveratrol (trans-3,4',5-trihydroxystibene) is a phytopolyphenol isolated from the seeds and skins of grapes. Recent studies indicate that resveratrol can block the process of multistep carcinogenesis, namely, tumor initiation, promotion and progression. Resveratrol can also reduce the risk of cardiovascular disease in man. The molecular mechanisms of resveratrol in chemoprevention of cancer and cardiovascular disease are interesting and under intensive investigation. Resveratrol was found to strongly inhibit nitric oxide (NO) generation in activated macrophages, as measured by the amount of nitrite released into the culture medium, and resveratrol strongly reduced the amount of cytosolic inducible nitric oxide synthase (iNOS) protein. The activation of nuclear factor kappa B (NF kappa B) induced by lipopolysaccharide (LPS) was inhibited by resveratrol. The phosphorylation and degradation of nuclear factor inhibitor kappa B alpha (I kappa B alpha) were inhibited by resveratrol simultaneously. Reactive oxygen species (ROS) are regarded as having carcinogenic potential and have been associated with tumor promotion. Resveratrol may act as a reactive oxygen species scavenger to suppress tumor development. In addition, resveratrol may block multistep carcinogenesis through mitotic signal transduction blockade. Reactive oxygen species are pivotal factors in the genesis of heart disease. Meanwhile, efficient endogenous antioxidants, including superoxide dismutase (SOD), glutathione peroxidase (GSHPx), and catalase, are present in tissues. A fine balance between reactive oxygen species and endogenous antioxidants is believed to exist. Any disturbance of this balance in favor of reactive oxygen species causes an increase in oxidative stress and initiates subcellular changes, leading to cardiomyopathy and heart failure. The experimental results indicate that exogenous antioxidant resveratrol is of value in chemopreventing the development of heart disease. It is urgent that more efforts be made to investigate newer therapies employing antioxidants for the chemoprevention of cardiovascular disease and cancer.

Elevation of apoptotic potential by anoxia hyperoxia shift in NIH3T3 cells

Apoptosis has been hypothesized to be mediated through the induction of free radicals via oxidative pathway. In this study, we demonstrated the induction of cellular apoptosis by anoxia-hyperoxia shift, but not by anoxia or hyperoxia alone in NIH3T3 cells. The decrement of ROS by anoxia thus appears to be an essential early event leading to apoptosis. G1 arrest was detected in anoxia-treated cells, and postanoxic oxygen recovery could reverse this effect, and induce apoptosis. On analysis of the binding activity of AP-1, we found biphasic induction of binding ability in cells undergoing anoxia-hyperoxia shift. In the early stage of anoxia, a transitional increase of AP-1 binding activity was detected, which was reduced to the minimal levels after 24 h of anoxia. During the period of postanoxic hyperoxia treatment, the binding activity of AP-1 was reinduced and increased remarkably with time up to 24 h. These results were in accordance with the expressions of c-jun and c-fos proteins. Enhancement of poly(ADP-ribosyl)ation activities, especially ADP-ribosylation of histone H1 was detected in post-anoxic hyperoxia-treated cells, and cleavage of PARP and activation of caspase 3 were also observed in post-anoxic hyperoxia (recovery) treated cells, but not in anoxia-treated cells. We propose that the differential induction of c-jun/c-fos (AP-1) gene expressions and sequential activation of PARP activity are essential in anoxia/hyperoxia-induced apoptosis.

Theaflavin-3,3'-digallate from black tea blocks the nitric oxide synthase by down-regulating the activation of NF-kappaB in macrophages

Nitric oxide (NO) plays an important role in inflammation and also in multiple stages of carcinogenesis. We investigated the effects of various tea polyphenols, including theaflavin, a mixture of theaflavin-3-gallate and theaflavin-3'-gallate, theaflavin-3,3'-digallate, thearubigin, and (-)-epigallocatechin-3-gallate on the induction of NO synthase in lipopolysaccharide-activated murine macrophages, RAW 264.7 cells. Theaflavin-3,3'-digallate was found to be stronger than (-)-epigallocatechin-3-gallate in inhibiting NO generation and inducible NO synthase protein in activated macrophages, while theaflavin, a mixture of theaflavin-3-gallate and theaflavin-3'-gallate and thearubigin were less effective. Inhibition of NO production was observed when cells were cotreated with theaflavin-3,3'-digallate and lipopolysaccharide. Western blot and reverse transcriptase-polymerase chain reaction (RT-PCR) analyses demonstrated that significantly reduced 130-kDa protein and mRNA levels of inducible NO synthase were expressed in lipopolysacchride-activated macrophages with theaflavin-3,3'-digallate, compared to those without theaflavin-3,3'-digallate. Electrophoretic mobility shift assay (EMSA) indicated that theaflavin-3,3'-digallate blocked the activation of nuclear factor kappaB (NF-kappaB), a transcription factor necessary for inducible NO synthase induction. Theaflavin-3,3'-digallate also blocked phosphorylation of IkappaB from cytosolic fraction and reduced lipopolysacchride-induced nuclear accumulation of transcription factor NF-kappaB p65 and p50 subunits. These results suggest that theaflavin-3,3'-digallate decreases the protein levels of inducible NO synthase by reducing the expression of inducible NO synthase mRNA, and the reduction could be via preventing the activation of NF-kappaB, thereby inhibiting the induction of inducible NO synthase transcription. It was also demonstrated that the gallic acid moiety of theaflavin-3,3'-digallate is essential for their potent anti-inflammation activity.

Suppression of nitric oxide synthase and the down-regulation of the activation of NFkappaB in macrophages by resveratrol

Resveratrol, naringenin and naringin are naturally occurring flavonoids in grapes and grapefruits. The anti-inflammatory effects of these flavonoids have been well documented, but the mechanism is poorly characterized. High concentration of NO are produced by inducible NO synthase (iNOS) in inflammation, and the prevention of the expression of iNOS may be an important anti-inflammatory mechanism. In this study, the effects of these flavonoids on the induction of NO synthase (NOS) in RAW 264.7 cells activated with bacterial lipopolysaccharide (LPS, 50 ng ml(-1)) were investigated. Resveratrol was found strongly to inhibit NO generation in activated macrophages, as measured by the amount of nitrite released into the culture medium, and resveratrol strongly reduced the amount of cytosolic iNOS protein and steady state mRNA levels. However, the inhibitory abilities of naringenin were lower, and the inhibitory abilities of naringin were almost negligible. In electrophoretic mobility shift assays, the activation of NFkappaB induced by LPS for 1 h was inhibited by resveratrol (30 microM). Furthermore, in immunoblotting analysis, cells treated with LPS plus resveratrol showed an inhibition of phosphorylation as well as degradation of IkappaBalpha, and a reduced nuclear content of NFkappaB subunits. The flavonoids may be of value for inhibiting the enhanced expression of iNOS in inflammation through down-regulation of NFkappaB binding activity.

CT of gastritis cystica polyposa

Gastritis cystica polyposa (GCP) is an uncommon lesion that usually occurs at the gastroenterostomy site, although occasionally it can be found in an unoperated stomach. We present a rare case of GCP which presented as a large polypoid mass in the gastric fundus and contained cystic components demonstrable on preoperative computed tomography.

Development of cerebral arterial innervation: synchronous development of neuropeptide Y (NPY)- and vasoactive intestinal polypeptide (VIP)-containing fibers and some observations on growth cones

The pre- and postnatal development of sympathetic fibers containing neuropeptide Y (NPY) and parasympathetic fibers containing vasoactive intestinal polypeptide (VIP) supplying the cerebral arteries were studied with immunohistochemistry in rats. The innervation patterns and densities of NPY and VIP fibers were similar at all stages of development and similar to that previously reported for norepinephrine (NE). There was a striking reorganization of the innervation pattern of all three fiber systems between the first and second postnatal weeks. At all stages of development prior to the first postnatal week, growth cones were present on individual fibers at the distal part of major cerebral arteries and the middle segment of the basilar artery. The growth cones had a range of shapes from blunt to stellate, lanceolate or filiform. NPY and VIP immunoreactive granules were commonly present. The present results taken with our earlier developmental study of NE fibers (J. Comp. Neurol., 271 (1988) 435-444), demonstrate that: (1) both sympathetic and parasympathetic perivascular nerves on immature cerebral vessels develop with similar sequences: first longitudinal fibers and fiber bundles are present; these transform to a meshwork pattern and finally transform again into the mature, predominantly circumferential pattern; (2) both the classical (NE) and peptidergic transmitters (NPY) within the sympathetic system appear to develop identically in terms of time of appearance, innervation patterns, densities and reorganization.(ABSTRACT TRUNCATED AT 250 WORDS)

Spurious hyperchloremia and decreased anion gap in a patient with dextromethorphan bromide

Although cold syrup containing dextromethorpan bromide is widely administered, the bromism due to cold syrup has not been reported. We report a patient who had negative anion gap with hyperchloremia and conscious loss because of daily intake of cold complex syrup (containing dextromethorphan bromide 0.4 mg/ml, acetaminophen 8.33 mg/ml) for headache for 4-5 years. The bromide content in cold complex syrup resulted in serum levels of bromide that interfered with the automated analyzers for chloride content. When conscious change is due to bromism, hemodialysis instead of forced hydration and diuresis should be performed immediately. Therefore, patients with a markedly negative anion gap with hyperchloremia should be considered as having halide intoxication.

Retinopathy, neuropathy and nephropathy in non-insulin-dependent diabetic patients

In 1978, an epidemiological survey for adult diabetes was conducted in Taipei City. A total of 219 Chinese non-insulin-dependent diabetic patients were discovered and 217 of them were examined for retinopathy, neuropathy and nephropathy. Among the 110 men and 107 women studied, 63.1% were free of complications and the prevalences for retinopathy, nephropathy and neuropathy were 24.0%, 12.9% and 23.5%, respectively. The clinical and biochemical data of the patients were compared. For those with and those without complications, the diabetic duration (8.2 +/- 6.7 vs 4.1 +/- 2.7, years), percentage of insulin treatment (8.8% +/- 0.7%), percentage of hypertension (42.5% vs 26.3%), and the fasting plasma glucose (182.8 +/- 63.6 vs 135.0 +/- 44.6, mg/dl) were significantly different. Diabetic duration and glycemic control consistently correlated with retinopathy, nephropathy and neuropathy. Hypertension and insulin treatment were also associated positively with the complications. The more complications the diabetic patients had, the poorer the glycemic control, the longer the diabetic duration, a higher percentage of insulin treatment and hypertension were found.

The impact of dietary sodium, potassium and calcium on blood pressure

A blood pressure survey was conducted in 3,886 male Taiwanese workers of a single Fukien ethnic group. Their mean age was 34 years. Hypertension defined as a systolic blood pressure of greater than or equal to 140 and/or diastolic blood pressure of greater than or equal to 90 mmHg was present in 370 subjects (9.5%). The high ethnic homogeneity in the study population allowed for an examination on the relationship between diet and blood pressure. A case control study was conducted in 161 subjects with elevated blood pressure and 154 subjects with normal blood pressure, randomly selected in each group, to assess the effects of dietary sodium, potassium and calcium on blood pressure. A 24-hour dietary recall was collected independently by a nutritionist. Using regression analysis, a significant (p less than 0.01) positive association of sodium intake and blood pressure was noted independent of age, body mass index and alcohol intake. The risk of elevated blood pressure was 2.5 times greater in men with a daily sodium intake of greater than 15g compared with those whose daily sodium intake was less than 15g. A negative association of calcium and potassium with blood pressure was noted in a group who ingested potassium greater than 2g and calcium greater than 0.5g daily. However, a statistical significance was achieved for calcium (p less than 0.01) but not for potassium (p = 0.15). These results indicate that dietary sodium and calcium are related to blood pressure and hypertension status within a unique and culturally homogeneous male group of Fukien ethnicity.

Cerebral arterial innervation: II. Development of calcitonin-gene-related peptide and norepinephrine in the rat

The pre- and postnatal development of trigeminal calcitonin-gene-related peptide (CGRP)- and sympathetic norepinephrine (NE)-containing nerves supplying the cerebral arteries was studied with immunohistochemistry in rats. At 18-19 days in utero (E 18-19), CGRP fibers were present only as one or two longitudinal bundles zigzagging along the anterior cerebral artery and anterior communicating artery. Growth-cone-like swellings were found at the terminals of individual fibers. In contrast, at this same prenatal age NE fibers were present as a meshwork on all cerebral arteries. The density of NE fibers was higher in the rostral than in the caudal parts of the circle of Willis; growth cones were present on individual fibers at the middle segment of the basilar artery and distal parts of major cerebral arteries. At postnatal day 1-2 (PND 1-2; date of birth = PND 1), the outgrowth of CGRP axons extended along the walls of the middle cerebral and internal carotid arteries. These axons were relatively straight and unbranched. At the same time, NE fibers increased in number and density and continued to form the meshwork pattern on all cerebral arteries. At the end of the first postnatal week, all the longitudinal NE bundles on the rostral part of the circle of Willis began to form circular arborizations. At the end of the second postnatal week, the pattern of NE innervation had completely changed, consisting almost entirely of circumferential rather than tangential fibers. Beginning in the first postnatal week, CGRP fibers increased greatly in number and density and began to form a meshwork pattern. At the second postnatal week, the pattern of CGRP innervation, compared to the pattern at fetal and neonatal stages, had changed significantly, consisting predominantly of a meshwork pattern. By 4 weeks after birth, both the NE and CGRP fiber systems achieved adult densities and patterns. The present results demonstrate the following: 1) Both sympathetic-NE and trigeminal-CGRP innervation of cerebral arteries begin in utero; the NE system innervates corresponding parts of the vessels earlier than the CGRP system. 2) Both NE and CGRP fibers are more dense in the rostral than in the caudal segments of the circle of Willis; this rostrocaudal gradient is expressed in both density and pattern by the earliest fibers of both neurochemical systems and is maintained throughout all developmental stages.(ABSTRACT TRUNCATED AT 400 WORDS)

Primary mediastinal seminoma

Primary mediastinal seminoma is a rare neoplastic disease. Only 133 cases have been reported in the literature. Five patients with primary mediastinal seminoma had been treated at VGH from 1974 to 1986. All of them received exploratory thoracotomy but only two of them were resectable. Postoperative radiation therapy was given regardless of resection. One had additional chemotherapy due to nodal involvement. All five patients showed complete resolution and were alive and free of disease for an average follow-up period of 42.6 months (range, 5-82 months). So we conclude that mediastinal seminoma is a rare neoplastic disease and can be treated primarily by surgery. Irradiation can also induce complete remission and long term survival in those with unresectable tumors.

Cerebral arterial innervation by nerve fibers containing calcitonin gene-related peptide (CGRP): I. Distribution and origin of CGRP perivascular innervation in the rat

The origin, density and distribution of calcitonin gene-related peptide (CGRP) immunoreactivity in cerebral perivascular nerves and the trigeminal ganglion of rats were examined in this study. CGRP immunoreactive axons were abundant on the walls of the rostral circulation of the major cerebral arteries in the circle of Willis. The fibers form a grid- or meshwork of longitudinal and circumferential axons studded with numerous varicose swellings. The density of CGRP fibers was particularly high at the bifurcation of major arteries. A few CGRP fibers cross the midline to innervate arteries on the contralateral side of the arterial tree. The arteries of the caudal circulation were sparsely innervated by CGRP fibers. In the trigeminal ganglion, about 30% of the ganglion cells had CGRP immunoreactivity. The cell size of most (75%) of CGRP neurons was less than 30 micron in diameter. There was no significant difference in staining density between small and large CGRP neurons. Unilateral transection of the maxillary and mandibular divisions of the trigeminal nerve caused a substantial decrease of CGRP immunoreactivity in the ipsilateral dorsal two-thirds of the trigeminal nucleus and cervical spinal cord but did not noticeably change the diameter of the vascular lumen or the densities of CGRP fibers in the walls of the cerebral arteries. In contrast, unilateral transection that included the ophthalmic division eliminated CGRP fibers on the ipsilateral cerebral arteries and eliminated CGRP immunoreactivity throughout the trigeminal nucleus in the brainstem and rostral cervical cord. In addition, these lesions caused a significant reduction in the diameter of the denervated arteries. The present study demonstrates that CGRP, a putative neurotransmitter/neuromodulator, is especially abundant in the rostral cerebral circulation and is derived from the ipsilateral ophthalmic division of the trigeminal nerve. In addition, the loss of CGRP perivascular nerves is associated with a reduction of the arterial lumen. This suggests that CGRP is a strong candidate as a nerve-derived trophic factor at trigeminal terminals and provides additional evidence that CGRP is a component in the trigeminovascular system influencing vascular diameter.

Chest radiography in the emergency department

A review of the medical literature was carried out to determine guidelines for cost-effective and safe use of chest radiography in the emergency department. Screening radiographs are indicated in specific populations in the search for occult tuberculosis or carcinoma and in routine or preoperative cases. Radiography is clinically indicated in the asthmatic patient, the elderly patient, and the symptomatic patient, and its indications are modified by the patient's age and presenting signs and symptoms. Based on the information reviewed, rational guidelines for the use of chest radiography are presented.

Traumatic intracavernous carotid aneurysm with massive epistaxis

Five cases of traumatic intracavernous carotid aneurysm are presented. All of the patients were young men with a history of severe head injury. The clinical manifestations were massive epistaxis and an ipsilateral cavernous sinus syndrome. The diagnosis was made correctly by carotid angiography. All of the patients developed another episode of massive epistaxis after admission. Emergency trapping of the internal carotid artery was performed. An urgent rescue method was used in one of our patients to prevent exsanguination before definitive surgical treatment. One patient died of exsanguination in spite of emergency ligation of the internal carotid artery. In the other four patients, no epistaxis was experienced after the operation.

Spinal intramedullary pseudocyst. Case report

The authors describe a case of a spinal intramedullary pseudocyst at T-1 that did not communicate with the surrounding spaces. The cystic wall was composed of dense connective tissue without epithelial or neoplastic cells. The patient's condition improved dramatically after surgical removal of the cyst. The literature on spinal intramedullary cystic lesions is reviewed and the etiology of pseudocysts is discussed. This case is believed to be the first in which a pseudocyst has been demonstrated within the spinal cord.

Horseradish peroxidase localization of the sympathetic postganglionic neurons innervating the cat heart

The localization of the sympathetic postganglionic neurons innervating the cat heart has been investigated by using retrograde axonal transport of horseradish peroxidase (HRP). HRP was injected into the subepicardial layers of 4 different cardiac regions. The animals were sacrificed 72-96 h later and fixed by perfusion via the left ventricle. The paravertebral sympathetic ganglia from the superior cervical, middle cervical and stellate ganglia to T10 ganglia were removed and processed for HRP identification. Following injections of HRP into the apex of the heart, the sinoatrial (SA) nodal region and the ventral wall of the right ventricle, we observed that HRP-labeled sympathetic neurons were localized predominantly in the right stellate ganglia, and to a lesser extent, in the right superior and middle cervical ganglia, and left stellate ganglia. Fewer labeled cells were found in the right T4-T6. T8 and T9. After HRP injection into the dorsal wall of the left ventricle, HRP-labeled cells were present mainly in the left stellate ganglia.

Retrograde localization of the innervation of the middle cerebral artery with horseradish peroxidase in cats

The innervation of the middle cerebral artery (MCA) of the cat was studied by applying horseradish peroxidase (HRP) to the wall of the right MCA. After a survival period of 48 to 72 hours, the bilateral superior cervical ganglia, middle cervical ganglia, stellate ganglia, T-4 sympathetic paravertebral ganglia, geniculate ganglia, semilunar ganglia, nodose ganglia, and brain stem including midbrain, pons, and medulla oblongata were removed to be processed with tetramethyl benzidine. HRP-labeled neurons were found in the ipsilateral superior cervical ganglion, semilunar ganglion, and dorsal raphe nucleus. The other areas did not have HRP activity. The results suggest that the adrenergic nerves innervating the MCA originate in the ipsilateral superior cervical ganglion, the sensory nerves originate in the ipsilateral semilunar ganglion, and the serotonergic nerves originate in the ipsilateral dorsal raphe nucleus. Cerebral arterial constriction may relate to the intrinsic (intracerebral) neurogenic pathway involving the trigeminal nerve and the dorsal raphe nucleus.

Effects of brain epinephrine depletion on thermoregulation, reflex bradycardia, and motor activity in rats

Two hours after i.p. administration of 2-cyclooctyl-2-hydroxyethylamine (CONH), 1-aminomethylcycloundecanol (CUNH), 2,3-dichloro-alpha-methylbenzylamine (DCMB), or 7,8-dichloro-1,2,3,4-tetrahydroisoquinoline (SKF64139), the hypothalamic and brain stem epinephrine (EPI) contents of rat brain were decreased. Depletions of brain EPI with these phenylethanolamine N-methyltransferase (PNMT) inhibitors reduced the rectal temperatures of rats at ambient temperatures of 8 and 22 degrees C. The hypothermia in response to these PNMT inhibitors was due to decreased metabolism and cutaneous vasodilatation. The locomotor stimulant responses induced by thyrotropin-releasing hormone were also reduced by administration of any one of these PNMT inhibitors. On the other hand, acute administration of any of these PNMT inhibitors enhanced the reflex bradycardia induced by i.v. infusion of EPI. The data suggest that brain (particularly the hypothalamus and brain stem) EPI-containing neurons are involved in the regulation of body temperature, reflex bradycardia, and motor performance in the rat.

Cholecystokinin acts through catecholaminergic mechanisms in the hypothalamus to influence ingestive behaviour in the rat

Administration of cholecystokinin (CCK) (0.2 - 0.6 micrograms in a volume of 2 microliter) into the lateral cerebral ventricle caused a decrease in intake of food but a relative increase in intake of water (or water-to-food ratio) in rats. To determine whether the anorexic actions of CCK were mediated through the hypothalamic nuclei, rats were infused with CCK (0.02 - 0.12 microgram in a volume of 0.5 microliter) through previously implanted hypothalamic cannulae. Administration of CCK into the lateral hypothalamus, but not the anterior hypothalamus or ventromedial hypothalamus, caused decreased intake of food and a relative increased intake of water. In addition, the responses induced by injection of CCK into the hypothalamus were completely abolished by selective depletion of catecholamines in the hypothalamus (eg. noradrenaline and dopamine) with intra-hypothalamic injection of 6-hydroxydopamine. Intraperitoneal administration of 0.12 microgram of CCK had no effect on the intake of food and water in rats. The data indicate that CCK acts through catecholaminergic mechanisms in the hypothalamus to influence feeding behaviour.

Effects of pre-ganglionic decentralization or post-ganglionic excision of the superior cervical ganglia on brain edema and heat stroke in rats

The preventive effect of pre-ganglionic decentralization (Sympathetic trunk resectioN) or postganglionic excision (ganglionectomy) of the superior cervical ganglia on thermal injury induced brain edema or the development of heat stroke was assessed in rats. Brain edema was induced by cold or heat injury to the cortex in 24 rats. The results showed that decentralization, but not excision, of the superior cervical ganglia greatly inhibited the formation of brain edema which was subsequently induced. When heat stroke was induced by exposing 24 rats to an ambient temperature of 41 degree C, the latency for the onset of the heat stroke and the survival time after the heat stroke were greatly prolonged by the former surgical procedure, but shortened by the later one. The present study demonstrates the potential benefit to brain edema and heat stroke of the pretreatment with decentralization of the superior cervical ganglia.

Experimental study on the pathogenesis of heat stroke

A heat-balance study was carried out on conscious rabbits exposed to ambient temperatures (Ta) from 8 degrees to 40 degrees C. At Ta = 40 degrees C, heat gain exceeded heat loss and led to hyperthermia and heat stroke, and the latency for the onset of heat stroke was found to be around 87 minutes. At the onset of heat stroke, the comatose animals showed higher levels of rectal temperature, ear skin blood flow, respiratory evaporative heat loss, metabolic rate, intracranial pressure (ICP), and cerebral water content as compared to those of control animals (kept at an ambient temperature of 24 degrees C). Before the start of heat stress, the animals had an average mean arterial blood pressure (MABP) of 94 mm Hg and cerebral perfusion pressure (CPP) of 80 mm Hg. However, at the onset of heat stroke, the average MABP and CPP decreased to 67 and 19 mm Hg, respectively. The reduction in CPP at the onset of heat stroke was due to both a decrease in MABP and an increase in ICP. In addition, the comatose animals which received an intravenous infusion of 10% glycerol (3 ml/min) had a survival time (interval between onset of heat stroke and death) longer than that of the comatose animals which received the control-vehicle solution. The prolongation of survival time in the glycerol-treated animals may be due to lower rectal temperature, lower cerebral water content, or lower ICP during the development of heat stroke. The present data indicate that not only hyperthermia but also cerebral edema, intracranial hypertension, decreased MABP, and decreased CPP are the main causes of heat stroke. The therapeutic values of glycerol on heat stroke may be related to the depressant action on cerebral edema, intracranial hypertension, and body temperature.

Intracerebral hematoma simulating a new growth

Three cases of organized intracerebral hematomas presented slowly progressive neurological deficits and hence mimicked brain tumors. Computed tomography scanning revealed ring enhancement of intracerebral mass lesions with midline shift. Angiographic studies showed avascular mass lesions. Soft, well-encapsulated, organized, large intracerebral hematomas with feeding arteries on their capsules were removed surgically. The lesions contained fresh and old hemorrhages. It is presumed that the feeding artery caused slowly continuous bleeding, thus causing these intracerebral hematomas to grow in a manner that made their clinical picture simulate that of intracerebral neoplasms. Their pathogenesis is discussed.