Coexistence of autonomic and somatic mechanisms in the pressor areas of medulla in cats.

The effects of electrical stimulation and microinjection of sodium glutamate (0.5 M) in the sympathetic pressor areas of the dorsal medulla (DM), ventrolateral medulla (VLM), and parvocellular nucleus (PVC) on the knee jerk, crossed extension, and evoked potential of the L5 ventral root produced by intermittent electrical stimulation were studied in 98 adult cats anesthetized with chloralose and urethane. During electrical and glutamate stimulation of these pressor areas, in addition to the rise of systemic arterial blood pressure marked inhibition of the spinal reflex was produced, indicating presence of neuronal perikarya responsible for these actions. Mild to moderate augmentation of spinal reflexes was also observed during brain stimulation but only in a few cases. The magnitude of the somatic effects among the pressor areas of the VLM, DM, and PVC subsequent to glutamate activation was about the same. Induced spinal reflex inhibition, independent from the baroreceptor and vagal influence, remained essentially unaltered after acute midcollicular decerebration. The inhibition was also observed in cats decerebellated 8-10 days in advance. The inhibition was not affected after bilateral electrolytic- or kainic-acid-induced lesions in the paramedian reticular nucleus (PRN). On the contrary, PRN-induced spinal reflex inhibition was attenuated after bilateral lesions in the DM or VLM. Data suggest that there coexists neuronal subpopulations in the VLM, DM, and PVC that can affect both the sympathetic pressor systems and spinal reflexes.     

The nNOS/cGMP signal transducing system is involved in the cardiovascular responses induced by activation of NMDA receptors in the rostral ventrolateral medulla of cats

The potential neuroprotective effects of the novel nitro-derivate of aspirin (NCX4016) on permanent focal cerebral ischemia in spontaneously hypertensive rats (SHRs) was investigated. Reference compounds were acetylsalicilic acid (ASA) and FK506 (tacrolimus). Ten minutes after surgery, SHRs were randomly divided into four groups of ten, pharmacologically treated and sacrificed 24 h after treatment. Brains were removed and processed to measure infarct volume, 70 kDa heat shock protein (hsp70), glial fibrillary acidic protein (GFAP) and vimentin (Vim) immunoreactivity (IR), and apoptosis using terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-digoxigenin nick end-labeling (TUNEL) assay. NCX-4016 significantly reduced total infarct volume compared to ASA (-20%, P < 0.05), FK506 (-18%, P < 0.05) and vehicle treatment (-20%, P < 0.05). Experimental groups did not differ in hsp70-IR and GFAP-IR. Conversely, hyperplastic astrocytes, measured by Vim-IR, were significantly lower in NCX-4016 than in the vehicle group (-36%, P<0.01). TUNEL assay indicated a significantly lower degree of apoptosis in NCX-4016 group than vehicle in both the homolateral (-27%, P < 0.01) and contralateral hemisphere (-29%, P < 0.05). These findings indicate that NO release associated with aspirin confers neuroprotective effects against ischemic injury.     

Immunohistochemical localization of apolipoproteins A-I and B in human carotid arteries

Decreased plasma levels of apolipoprotein A-I (apo A-I) and increased plasma levels of apolipoprotein B (apo B) have been shown to correlate with increased risk of atherosclerosis. While many studies have investigated the plasma levels of these apolipoproteins with regard to their value as predictors of cardiovascular disease, comparatively little is known about their precise tissue localization in atherosclerotic plaques. The purpose of this study was to determine the tissue localization of apo A-I and apo B in atherosclerotic segments of human carotid arteries through the use of immunohistochemical techniques. With tissue samples obtained from surgery and autopsy, apo A-I and apo B were found to be present in atherosclerotic plaques and absent in normal arterial tissue. In the plaques, both apo A-I and apo B were found extracellularly, primarily in the lipid core, but also in connective tissue. In addition, both apo A-I and apo B were found intracellularly in foam cells. This similar intracellular and extracellular distribution of apo A-I and apo B was unexpected, in view of their differing associations with atherosclerosis.     

Therapeutic potential of chlorotoxin-like neurotoxin from the Chinese scorpion for human gliomas

Chlorotoxin, one of the key toxins in scorpion Leiurus quinquestriatus venom, has been shown to bind specifically to glioma cell surface as a specific chloride channel blocker. In this study, a purified, recombinant chlorotoxin-like peptide from the scorpion Buthus martensii Karsch (named rBmK CTa) was characterized by in vivo and in vitro studies. The results from cell proliferation assay with human glioma (SHG-44) cells showed that rBmK CTa inhibits the growth of glioma cells in a dose-dependent manner, with an IC₅₀ value of approximately 0.28 μM. Under the same conditions, the IC₅₀ value for normal astrocytes increased to 8 μM. This clearly indicated that rBmK CTa had specific toxicity against glioma cells but not astrocytes. Results from whole-cell patch-clamp recording showed that chloride current in SHG-44 was inhibited by rBmK CTa in a voltage-dependent manner and percent inhibitions for the blocking action of rBmK CTa (0.07 and 0.14 μM) on I_Cl was 17.64 ± 3.06% and 55.86 ± 2.83%, respectively. Histological analysis of rBmK CTa treated mice showed that brain, leg muscle and cardiac muscle were the target organs of this toxin. These results suggest that rBmK CTa may have potential therapeutic application in clinical treatment of human glioma. It represents an approach for developing a novel therapeutic agent.     

Timing of odontogenic neural crest cell migration and tooth-forming capability in mice.

The mammalian tooth develops through sequential and reciprocal interactions between cranial neural crest (CNC)- derived ectomesenchymal cells and the stomadial epithelium. Classic tissue recombination studies demonstrated that premigratory CNC cells and CNC-derived ectomesenchymal cells possess odontogenic capacity and can respond to oral epithelial signals to form a tooth, suggesting that the CNC cells contributing to odontogenic tissue are not prespecified. Here we show that, in mice, CNC cells have populated the forming first branchial arch before the 9-somite stage and continue to migrate into the arch by the 13-somite stage. Grafts of the first arch from the 10-somite embryo or earlier yielded membranous bone and cysts but no teeth after subrenal culture. However, grafts of the first arch with its dorsally adjacent tissue containing migrating neural crest cells from the same age embryos gave rise to teeth. In contrast, teeth formed in first arch grafts that do not contain migrating neural crest cells from embryos with 12 or more somites. Interestingly, the acquisition of tooth forming capability in the first arch coincides with the onset of Fgf8 expression in the oral epithelium. These results suggest that there exists a population of odontogenic neural crest cells that migrates into the first arch between the 10- and 12-somite stages. These cells either possess odontogenic potential and are able to initiate tooth development, or can respond to odontogenic signals derived from the oral epithelium to support tooth formation.     

Comparison of local risk factors for children's atopic symptoms in Hanoi, Vietnam

BACKGROUND: A 1999 study in Hanoi, Vietnam using the International Study on Asthma and Allergies in Childhood (ISAAC) questionnaire showed a high prevalence of atopic symptoms. Identifying risk factors for symptoms in these children may help in understanding the causes for these high estimates. METHODS: An ISAAC questionnaire with supplemental questions on environmental variables was distributed to 5495 school children in Hanoi and a suburban district, Dong Anh. The response rate was 65.7%. RESULTS: In Dong Anh, the following were among the significant age and gender adjusted associations: pig ownership [odds ratio (OR) (95% confidence interval), OR = 1.79 (1.18-2.70) for doctor-diagnosed asthma (DDA), OR = 1.72 (1.08-2.78) for doctor diagnosed hay fever (DDHF)] and farming [OR = 1.67 (1.27-2.19) for ever asthma, OR = 1.51 (1.09-2.09) for DDHF]. In multivariate models, tuberculosis (TB) was a significant predictor of atopic symptoms [Hanoi: OR = 3.09 (1.10-8.70) for DDA, Dong Anh: OR = 3.71 (1.40-9.84) for DDA, OR = 4.66 (1.88-11.57) for DDHF]. CONCLUSIONS: These findings are contrary to the "hygiene hypothesis". Recent immunologic and epidemiologic studies refute the inverse association between allergy and TB and may be one explanation for the positive association in this study. The positive association with pig ownership and farming may be because of exposures on farms in a developing country that may be different from exposures in farms of developed countries.     

阿苯达唑乳治疗包虫病及犬用长效缓释驱虫剂的研究

包虫病是流行于我国西部地区的一种严重的人畜共患寄生虫病。全国有22个省、市和自治区有本病发生,垒1990年底止仅西部6个省     

Outcomes and complications of naftopidil versus tamsulosin for elderly men with lower urinary tract symptoms secondary to benign prostatic hyperplasia: A systematic review and meta-analysis

We conducted a systematic review and meta-analysis to assess the outcomes and complications of naftopidil in treating elderly men with lower urinary tract symptoms secondary to benign prostatic hyperplasia and compared them with those administered with tamsulosin. A literature review was performed to identify the available randomised controlled trials concerning the comparison between naftopidil and tamsulosin for men with LUTS/BPH. We searched the following databases: the Cochrane Library Database, PubMed, Embase and Web of Science. Eleven publications involving 1,114 men (557 in the naf group and 557 in the tam group) were pooled in our analysis. We found no significant differences in the total IPSS, IPSS storage score, IPSS voiding score, quality of life index, peak urinary flow rate, average flow rate and post-void residual volumes. We assessed cardiovascular and sexual adverse events, acute urinary retention, surgical intervention, withdrawals due to any reason and withdrawals due to adverse events. The incidence of adverse events was similar among patients in naf and tam groups. In conclusion, naftopidil shared comparable efficacy and similar incidence of adverse events with tamsulosin and appears to be a promising agent for and alternative to tam. However, more prospective trials with high quality and long-term treatment duration are needed to verify this observation.