[A comparative study of artificial intelligence nasal polyp classification based on whole-slide imaging and JESREC diagnostic criteria].

Objective: To explore the types and clinical characteristics of chronic rhinosinusitis with nasal polyps (CRSwNP) based on artificial intelligence and whole-slide imaging (WSI), and to explore the consistency of the diagnostic criteria of the Japanese epidemiological survey of refractory eosinophilic chronic rhinosinusitis (JESREC) in Chinese CRSwNP patients. Methods: The data of 136 patients with CRSwNP (101 males and 35 females, aging 14 to 70 years) who underwent endoscopic sinus surgery from 2018 to 2019 in the Department of Otorhinolaryngology Head and Neck Surgery, the Third Affiliated Hospital of Sun Yat-sen University were analysed retrospectively. The preoperative clinical characteristics of patients were collected, such as visual analogue scale (VAS) of nasal symptoms, peripheral blood inflammatory cell count, total immunoglobulin E (IgE), Lund-Kennedy score and Lund-Mackay score. The proportion of inflammatory cells such as eosinophils, lymphocytes, plasma cells and neutrophils were calculated on the WSI of each patient through artificial intelligence chronic rhinosinusitis evaluation platform 2.0 (AICEP 2.0), and the specific type of nasal polyps was then obtained as eosinophilic CRSwNP (eCRSwNP) or non-eosinophilic CRSwNP (non-eCRSwNP). In addition, the JESREC diagnostic criteria was used to classify the nasal polyps, and the classification results were compared with the current gold standard for nasal polyps diagnosis (pathological diagnosis based on WSI). The accuracy, sensitivity and specificity of the diagnostic criteria of JESREC were evaluated. The data were expressed in M (Q1, Q3) and statistically analyzed by SPSS 17.0. Results: There was no significant difference between eCRSwNP and non-eCRSwNP in age distribution, gender, time of onset, total VAS score, Lund-Kennedy score or Lund-Mackay score. However, there was a significant difference in the ratio of nasal polyp inflammatory cells (eosinophils 40.5% (22.8%, 54.7%) vs 2.5% (1.0%, 5.3%), neutrophils 0.3% (0.1%, 0.7%) vs 1.3% (0.5%, 3.6%), lymphocytes 49.9% (39.3%, 65.9%) vs 82.0% (72.8%, 87.5%), plasma cells 5.1% (3.6%, 10.5%) vs 13.0% (7.4%, 16.3%), χ2 value was 9.91, 4.66, 8.28, 5.06, respectively, all P<0.05). In addition, eCRSwNP had a significantly higher level of proportion of allergic symptoms (nasal itching and sneezing), asthma, peripheral blood eosinophil and total IgE (all P<0.05). The overall accuracy, sensitivity and specificity of the JESREC diagnostic criteria was 74.3%, 81.3% and 64.3%, respectively. Conclusions: The eCRSwNP based on artificial intelligence and WSI has significant high level of allergic symptoms, asthma, peripheral blood eosinophils and total IgE, and the percentages of inflammatory cells in nasal polyps are different from that of non-eCRSwNP. The JESREC diagnostic criteria has good consistency in our research.

[Efficacy of endovascular treatment of distal aortic dissection involving abdominal visceral segment with bare-metal stents related technique].

Objective: To investigate the effect of bare-metal stent related technique on distal aortic dissection involving abdominal visceral segment. Methods: A retrospective analysis was performed on clinical data of 33 patients with distal aortic dissection involved abdominal visceral segment, who hospitalized in the Vascular Surgery Department of Shanghai Changhai Hospital from July 2012 to September 2019. The effect of the treatment was evaluated according to the clinical and preoperative, intraoperative and follow-up imaging data derived from (aorta computed tomography angiography (CTA) and digital subtraction angiography (DSA)) as well as the changes of the maximal diameter of the aorta and the thrombosis of the false lumen of the dissection. The criteria were as follows: the maximum diameter change of aortic dissection<5 mm was defined as stable; the maximum diameter decrease of aortic dissection≥5 mm was defined as effective reduction; the maximum diameter increase of aortic dissection≥5 mm was defined as expansion; the definition of diameter change of false lumen was the same as above. The hospital complications, clinical symptoms and survival were recorded. Results: There were 28 male patients in this cohort, the mean age was (57.6±4.9) years old. Twenty-one patients were treated with bare-metal stent and coils technique, of which 8 patients were jointly treated with stent grafts. Twelve patients were treated with multi-layer bare-metal stent technique, of which 4 patients were jointly treated with stent grafts. Intraoperative DSA image results showed that the visceral arteries were patent during the treatment, and the blood flow velocity of the false lumen was reduced in all 33 patients. There were no adverse events such as distal outflow tract embolism and coil displacement during the operation. During the period of hospitalization, one patient developed intimal rupture of subrenal abdominal aortic dissection on the fourth day after operation and emergency endovascular graft exclusion was performed for abdominal aortic dissection, and the patient recovered well from the emergency operation. The follow-up time was (16.7±14.0) months. One patient died 1 year after surgery due to non-disease-related factors. Follow-up CTA imaging results showed that the maximum diameter of the aorta in abdominal visceral segment tended to be smaller ((39.1±13.4) mm vs. (41.3±11.9) mm, P=0.469), and the maximum diameter of the false lumen was significantly reduced ((16.2±12.9) mm vs. (23.5±10.7) mm, P=0.014). The maximum diameter of the aortic dissection was reduced in 12 cases, stable in 19 cases, expanded in 2 cases. The maximum diameter of the false lumen was effectively reduced in 22 cases, stable in 10 cases, and expanded in 1 case. Four patients developed small endoleak in the false lumen, one of them was nearby the renal artery stent, and the remaining patients experienced complete thrombosis of the false lumen. Conclusions: Endovascular treatment of distal aortic dissection involving abdominal visceral segment with bare-metal stents related technique could promote the shrink and the thrombosis of the false lumen, and slow down the blood flow from the tear into the false lumen in the setting of patency of visceral arteries.

[Using the big data of internet to understand the characteristics of coronavirus disease 2019: a big data study].

Objective: To analyze the symptom characteristics of Coronavirus Disease 2019(COVID-19) and to improve its prevention by using big data. Methods: Using Baidu Index Platform (http://index.baidu.com) and the website of Chinese Center for Disease Control and Prevention as data resources, we obtained the search volume (SV) of keywords for symptoms associated with COVID-19 from January 1 to February 20 in each year from 2017 to 2020, in Hubei province and other top 10 impacted provinces in China and the epidemic data. Data of 2020 were compared with the previous three years. Data of Hubei province were compared with confirmed cases. The differences and characteristics of the SV of COVID-19-related symptoms, and the correlation between the SV of COVID-19 and new confirmed or suspected cases were analyzed and the hysteresis effects were discussed. R3.6.2 software was used to analyze the data. Results: Compared the data from January 1 to February 20, 2020, with the SV for the same period of previous three years, Hubei's SV for cough, fever, diarrhea, chest tightness, dyspnea and other symptoms were significantly increased. The total SV of lower respiratory symptoms was significantly higher than that of upper respiratory symptoms (P<0.001). The SV of COVID-19 in Hubei province was significantly correlated with new confirmed or suspected cases (r(confirmed)=0.723, r(suspected)=0.863, all P<0.001). The results of the distributed lag model suggested that the patients who retrieved relevant symptoms on the internet may begin to see a doctor in 2-3 days later and be diagnosed in 3-4 days later. Conclusions: The total SV of lower respiratory symptoms is higher than that of upper respiratory symptoms, and the SV of diarrhea also increases significantly. It warns us to pay attention to not only the symptoms of lower respiratory tract, but also the gastrointestinal symptoms, especially diarrhea in patients with COVID-19. There is a relationship between internet retrieval behavior and the number of new confirmed or suspected cases. Big data have a certain role in the early warning of infectious diseases.

Di-2-ethylhexyl phthalate (DEHP) exposure disturbs lipid metabolism in juvenile yellow catfish Tachysurus fulvidraco.

This study was conducted to determine the mechanism by which di-2-ethylhexyl phthalate (DEHP) exposure influences lipid metabolism of juvenile yellow catfish Tachysurus fulvidraco. Fish were exposed to three DEHP concentrations (0, 0·1 and 0·5 mg l-1 DEHP) for 8 weeks. Fatty acid synthase (FAS) activity significantly decreased with increasing DEHP concentrations, the highest value was in the Tween control group, whereas the lowest activities of carnitine palmitoyltransferase (CPT) and lipoprotein lipase (LPL) were in this group. The messenger (m)RNA levels of 6-phospho-gluconate dehydrogenase (6PGD), FAS and acetyl-CoA carboxylase a (ACCa) significantly increased with increasing DEHP concentration, the highest values were in the 0·5 mg l-1 DEHP group. The mRNA level of peroxisome proliferator-activated receptor γ (PPARγ) was lower in Tween control than in fish exposed to 0·1 and 0·5 mg l-1 DEHP. The highest mRNA level of ACCb was in the 0·1 mg l-1 DEHP group. These results indicate that DEHP exposure can disturb lipid metabolism at the enzymatic and mRNA levels in Pelteobagrus fulvidraco.

The Unhealthy Lifestyle Factors Associated with an Increased Risk of Poor Nutrition among the Elderly Population in China.

OBJECTIVES: The associations between nutritional status and lifestyle factors have not been well established. This study aimed to investigate the prevalence of poor nutrition and to examine the relationships between nutritional status and unhealthy lifestyle and other related factors among the elderly. METHODS: This cross-sectional study was conducted in Liaobu Town, Dongguan city, China. A total of 708 community-dwelling older adults aged ≥60 years were recruited by stratified random sampling. Data on sociodemographic characteristics, health and lifestyle factors, and the Mini Nutritional Assessment (MNA) scores were collected using structured questionnaires via face-to-face interviews. A multivariate logistic regression model was constructed to identify the risk factors of poor nutrition. RESULTS: The prevalence of malnutrition among the elderly adults in this study was 1.3%, and 24.4% were at risk of malnutrition (RM). Poor nutrition was significantly associated with female gender, older age, lower education, a high number of self-reported chronic diseases, and hospitalization in the last year. Unhealthy lifestyle factors associated with poor nutrition included current smoking status, higher alcohol consumption, lack of physical activity, longer duration of sitting, negative attitude towards life, and a poor family relationship. CONCLUSIONS: While the prevalence of malnutrition was low, RM was high in the elderly population in China. The determinants of malnutrition were explored and the relationships between nutritional status and unhealthy lifestyle factors were examined. The results of this study provide information for future longitudinal studies with multi-factorial interventional design in order to determine the effects of the causal relationships.

Assessment of genetic relationship among Rhododendron cultivars using amplified fragment length polymorphism and inter-simple sequence repeat markers.

Genetic relationships of 17 Rhododendron cultivars, China, were assessed using inter-simple sequence repeat (ISSR) and amplified fragment length polymorphism (AFLP) markers. A total of 133 bands were obtained using nine selected ISSR primers, 129 (96.99%) of which were polymorphic; 267 bands were amplified by four AFLP primer pairs, 251 (94.01%) of which exhibited polymorphism. Based on these polymorphic products, a cluster analysis revealed similarities between the results of the ISSR and AFLP. All of the cultivars were clustered into two major branches; one branch contained the same four cultivars, and the other cultivars were separated into different groups in the other branch. The cluster results showed that the genetic relationships of the 17 cultivars were partly related to their morphological characteristics, particularly the flowering phase. Therefore, the results of this study support the classification of Rhododendron cultivars according to flowering phase. In addition, the cluster results can be used to select suitable parents for breeding.

An association analysis of the rs1572931 polymorphism of the RAB7L1 gene in Parkinson's disease, amyotrophic lateral sclerosis and multiple system atrophy in China.

BACKGROUND AND PURPOSE: Recently, the rs1572931 single-nucleotide polymorphism (SNP) of the putative promoter of the member RAS oncogene family-like 1 (RAB7L1) gene was reported to be associated with reduced risk for Parkinson's disease (PD) in the Ashkenazi Jewish population. Ethnic-specific effects are an important consideration in genome-wide association studies. Considering that the clinical manifestations and pathological characteristics overlap between PD, amyotrophic lateral sclerosis (ALS) and multiple system atrophy (MSA), the possible associations between the rs1572931 SNP and these three diseases were studied in the Chinese population. METHODS: A total of 1011 PD patients, 778 sporadic ALS (SALS) patients, 264 MSA patients and 516 healthy controls (HC) were included in this study. All subjects were genotyped for the rs1572931 SNP by using polymerase chain reaction and direct sequencing. RESULTS: Significant differences were observed in the genotype and minor allele frequency (MAF) of rs1572931 between PD and HC (P = 0.0001 and P = 1.08E-04, respectively) and between late-onset PD and matched controls (P = 0.0011 and P = 0.0002, respectively). However, no differences were observed between early-onset PD and HC. The number of minor allele carriers was significantly lower in PD patients than in HC (P = 2.96E-05, odds ratio 0.63, 95% confidence interval 0.51-0.78). No differences were observed between groups with respect to sex, onset symptoms, absence or presence of cognition impairment, anxiety or depression. In addition, no differences were found in the genotype and MAF of rs1572931 between SALS and HC or between MSA and HC. CONCLUSION: Our results suggest that rs1572931 decreases the risk for PD but not for ALS and MSA in the Chinese population. However, the polymorphism is unlikely to be a common cause of SALS and MSA in the Chinese population.

Expression patterns and predictive value of phosphorylated AKT in early-stage breast cancer.

BACKGROUND: AKT phosphorylation is a critical step in the activation of growth factor receptors and can mediate tumor resistance to anthracyclines. We evaluated the expression patterns and predictive value of phosphorylated AKT (pAKT) in breast cancer tissues. PATIENTS AND METHODS: pAKT expression was assessed by immunohistochemistry in 823 tumors from patients with early breast cancer enrolled in two randomized trials. The distribution of pAKT expression was correlated with HER2 and epidermal growth factor receptor (EGFR) expression. The predictive value of pAKT for the efficacy of adjuvant chemotherapy was determined by test for interaction. RESULTS: pAKT, EGFR, and HER2 were expressed in 119 of 781 (15%), 118 of 758 (16%), and 99 of 775 (13%) assessable tumors. Staining was positive for pAKT in 28 of 99 (28%) and 90 of 676 (13%) HER2+ and HER2- tumors (P < 0.001). pAKT was expressed in 15 of 94 (16%) and 75 of 563 (13%) HER2-/EGFR+ and HER2-/EGFR- tumors, respectively (P = 0.49). A positive staining for pAKT did not correlate with prognosis (P = 0.94), and did not predict the resistance to anthracyclines (test for interaction, P = 0.70). CONCLUSIONS: AKT phosphorylation is associated with HER2 expression but not EGFR expression in patients with early breast cancer. pAKT is not predictive for the efficacy of anthracycline-based adjuvant chemotherapy.

Effects of omeprazole and ascorbate on gastric emptying and antioxidant levels in a mouse model of glutathione depletion.

Increased free radical production with depletion of the antioxidant, glutathione, is a suggested mechanism for the development of ulcer disease in patients with Helicobacter pylori. The effects of ascorbate and omeprazole as potential gut antioxidants are incompletely understood. We hypothesized that as antioxidants, ascorbate and omeprazole protect against glutathione depletion. This study was designed to determine the effects of ascorbate and omeprazole on gastric emptying and gastric antioxidant levels in a mouse model of glutathione depletion. In an acute (10-day) mouse model, glutathione depletion was induced by inhibiting the rate limiting enzyme, gamma-glutamylcysteine synthetase. Enzymatic blockade produced depletion of gastric glutathione (P < 0.05) without increasing gastric lipid hydroperoxides. Glutathione depletion was associated with accelerated liquid gastric emptying. These effects were not prevented by supplementation with ascorbate or omeprazole. Omeprazole induced increased (P < 0.05) gastric and colonic total antioxidant capacity. One of the beneficial effects of omeprazole in patients may involve increased total antioxidant capacity.

Total antioxidant capacity of colon in patients with chronic ulcerative colitis.

It has been proposed that oxidative stress is involved in the pathophysiology of ulcerative colitis. We have reported the depletion of the nonenzymatic antioxidant, glutathione, in colon from active and inactive ulcerative colitis. The colon contains several biochemically linked antioxidant systems. We hypothesized that diminished total antioxidant capacity in active ulcerative colitis would be associated with increased colonic lipid peroxidation. This study was designed to determine total antioxidant capacity and lipid hydroperoxide levels using colon obtained at surgery from controls (N = 16; 4 females, 12 males; mean age 70 years), and active and inactive ulcerative colitis (N = 15; 3 females, 12 males; mean age 39). Total antioxidant capacity of control colon was higher in muscularis externa compared to the mucosal-submucosal layer (P < 0.05). There were no differences in colonic total antioxidant capacity or lipid hydroperoxide levels comparing control colon to inactive and active ulcerative colitis. The results did not support depletion of tissue total antioxidant capacity by free radicals. Depletion of glutathione in ulcerative colitis may be a specific disorder rather than a secondary defect attributable to global oxidative stress. Nonspecific antioxidant supplements appear unlikely to be beneficial in the treatment of ulcerative colitis.

[Comparison of genetic diversity among maize inbred lines based on RFLPs, SSRs, AFLPs and RAPDs].

RFLPs, SSRs, AFLPs and RAPDs were used to detect the genetic diversity among 15 maize inbred lines. A total of 56 probe enzyme combinations, 66 SSR primers, 20 RAPD primers and 9 AFLP primer combinations were identified with polymorphism among the entries, which produced 167, 201, 180 and 87 alleles respectively. SSR markers have the highest polymorphism information content (PIC, 0.47) and AFLP markers have the lowest value (0.36), while AFLP markers possess the highest assay efficiency index (Ai, 32.4). A comparison of genetic similarity matrices revealed that the estimates of correlation coefficients based on RFLPs, SSRs, AFLPs and RAPDs were significantly correlated, but the correlation of RAPD maker data with other markers was lower. These inbred lines were classified into five groups based on four molecular markers data, which are Tangsipingtou, Luda Red Cob, Lancaster, Reid, and PN group. They are consistent with the grouping based on the available pedigree data. Based on the results, we recommend RFLPs and SSRs for genetic diversity analysis among maize germplasm.

Effect of ozone treatment on airway reactivity and epithelium-derived relaxing factor in guinea pigs.

Ozone (O(3)) is toxic to respiratory epithelium and causes airway inflammation and hyperreactivity. To evaluate the role of the epithelium in the development of hyperreactivity, we examined in guinea pigs the effects of inhaled O(3) (3 ppm for 1 h; 0-24 h after exposure) on 1) reactivity to inhaled methacholine (MCh), 2) reactivity of the isolated, perfused trachea (IPT) to MCh, 3) epithelium-derived relaxing factor (EpDRF)-mediated relaxations of IPT induced by mucosal hyperosmolar solutions, 4) neurogenic contraction and relaxation responses, 5) transepithelial potential difference, and 6) microscopic analysis of nitrotyrosine immunofluorescence, substance P fiber density, and tracheal morphology. At 0 h, O(3) caused hyperreactivity to inhaled MCh and mucosally but not serosally applied MCh in IPT (only in the presence of the epithelium) and a decrease in transepithelial potential difference. Inhibition of EpDRF-induced relaxation responses occurred at 2 h. All of these changes returned to control by 12 to 18 h. O(3) had no effect on neurogenic responses. Nitrotyrosine immunofluorescence appeared in the trachea at 0 h in detached epithelial cell ghosts and in intrapulmonary airways by 6 h. Substance P fiber density was elevated in smooth muscle at 0 and 18 h but not in epithelium or lamina propria of intrapulmonary and extrapulmonary bronchi. Loss of cilia and mucosubstances in the mucosa occurred at 0 h; the epithelium became markedly attenuated over 12 to 24 h. A reversible increase in epithelial permeability and a decrease in EpDRF production may contribute to O(3)-induced hyperreactivity to MCh.

Induction of enlarged intestinal lymphoid aggregates during acute glutathione depletion in a murine model.

Glutathione is a nonenzymatic antioxidant synthesized by most animal cells and is depleted in inflammatory bowel disease. The effects of glutathione depletion on intestinal histology and inhibitory neurochemicals was examined in a mouse model. Glutathione depletion in A/J mice involved inhibition of gamma-glutamylcysteine synthetase using L-buthionine-(S,R)-sulfoximine (BSO) for 10 days. Ileum and colon were obtained from saline-control mice, BSO-treated mice, and BSO-treated mice receiving ascorbate or glutathione monoethylester. Glutathione, lipid peroxides, and nicotineamide adenine dinucleotide phosphate diaphorase activity were measured by colorimetric assays. Vasoactive intestinal peptide was measured by radioimmunoassay. Glutathione depletion induced enlargement of mucosal-submucosal lymphoid aggregates without germinal centers in ileum and colon. These aggregates were prevented by supplementation with glutathione monoethylester but not ascorbate. Tissue levels of inhibitory neurochemicals were unchanged. Depletion of glutathione appears to induce enlarged lymphoid aggregates by recruitment of lymphocytes from the peripheral circulation. A component of the inflammation that develops in inflammatory bowel disease could be related to depletion of tissue levels of glutathione.

Osmotic regulation of airway reactivity by epithelium.

Inhalation of nonisotonic solutions can elicit pulmonary obstruction in asthmatic airways. We evaluated the hypothesis that the respiratory epithelium is involved in responses of the airways to nonisotonic solutions using the guinea pig isolated, perfused trachea preparation to restrict applied agents to the mucosal (intraluminal) or serosal (extraluminal) surface of the airway. In methacholine-contracted tracheae, intraluminally applied NaCl or KCl equipotently caused relaxation that was unaffected by the cyclo-oxygenase inhibitor, indomethacin, but was attenuated by removal of the epithelium and Na+ and Cl- channel blockers. Na+-K+-2Cl- cotransporter and nitric oxide synthase blockers caused a slight inhibition of relaxation, whereas Na+,K+-pump inhibition produced a small potentiation. Intraluminal hyperosmolar KCl and NaCl inhibited contractions in response to intra- or extraluminally applied methacholine, as well as neurogenic cholinergic contractions elicited with electric field stimulation (+/- indomethacin). Extraluminally applied NaCl and KCl elicited epithelium-dependent relaxation (which for KCl was followed by contraction). In contrast to the effects of hyperosmolarity, intraluminal hypo-osmolarity caused papaverine-inhibitable contractions (+/- epithelium). These findings suggest that the epithelium is an osmotic sensor which, through the release of epithelium-derived relaxing factor, can regulate airway diameter by modulating smooth muscle responsiveness and excitatory neurotransmission.

Nitric oxide synthase inhibitor and lipopolysaccharide effects on reactivity of guinea pig airways.

The in vivo and in vitro effects of nitric oxide (NO) synthase inhibitors and lipopolysaccharide (LPS) on reactivity of guinea pig airways were examined. In isolated, perfused tracheas from untreated animals, the NO synthase inhibitors, N omega-nitro-L-arginine methyl ester (L-NAME; 10(-4)M), NG-methyl-L-arginine (L-NMMA; 10(-4) M) and aminoguanidine (10(-4) M) had no effect or inhibited reactivity to extraluminally (EL) or intraluminally (IL) applied methacholine and histamine. L-NMMA (10(-4) M) did not appreciably contract resting or metacholine-contracted preparations (+/- 3 x 10(-4) M L-arginine) and L-arginine only weakly relaxed contracted tracheas (+/- L-NMMA). Sodium nitroprusside and S-nitroso-N-penicillamine elicited relaxant responses and were more potent extraluminally than intraluminally. Methylene blue (10(-5) M) antagonized relaxation to sodium nitroprusside. Incubation with Escherichia coli LPS (10 micrograms/ml; 30 min incubation) alone in the EL and IL baths depressed methacholine and histamine concentration-response curves. In the presence of LPS, L-NAME potentiated responses to intraluminally applied methacholine but did not affect responses to extraluminally added methacholine. Four days after i.p. injection of animals with LPS (4 mg/kg), L-NAME potentiated responses to IL methacholine, and L-arginine acquired greater relaxant activity. LPS injection increased sensitivity to intraluminally added but not extraluminally added isoproterenol. LPS given by i.p. injection or by inhalation did not affect basal specific airway resistance of conscious animals or reactivity to methacholine aerosol during a postexposure period of 6 to 72 h. NO seems to have little role in regulating reactivity of guinea pig airways to bronchoconstrictor agonists, except after in vitro or in vivo exposure to LPS. After LPS injection the in vitro changes suggestive of NO synthase induction are not associated with altered airway reactivity to inhaled methacholine.

Polarized effects of amiloride and 4,4'-diisothiocyano-stilbene-2,2'-disulfonic acid on ATP-induced contraction of trachea.

Polarity in the effects of amiloride and 4,4'-diisothiocyano-stilbene-2,2'-disulfonic acid (DIDS) in the guinea-pig isolated, perfused trachea was investigated to evaluate the roles of epithelial and airway smooth muscle Na+ and Cl- channels in the development of contractile responses to ATP. The blockers were applied to the mucosal (intraluminal) perfusing solution or to the serosal (extraluminal) bath before the second of two challenges with ATP (10(-4) M), which was added to the same bath as the blocker, or to the abluminal bath. In epithelium-intact tracheas, amiloride (10(-4) M) added to the extraluminal or intraluminal bath rapidly (1 min) and extensively inhibited contractions to extraluminally applied ATP (10(-4) M). In contrast, contractions to intraluminally applied ATP (10(-4) M) were relatively resistant to extraluminal and intraluminal amiloride (10(-4) M), in terms of the degree and onset of the inhibition. DIDS (10(-4) M) present in the extraluminal or intraluminal baths caused a slowly developing elevation of baseline tone. After a 30 min incubation, extraluminal DIDS potentiated responses to extraluminally added ATP, but intraluminal DIDS inhibited contractions to ATP added to the extraluminal and intraluminal baths. In contrast to the intact tracheas where there was no difference, the second response of epithelium-denuded preparations to intraluminally administered ATP was diminished. In rubbed tracheas the response to intraluminally added ATP was inhibited further by intraluminal amiloride but was potentiated by intraluminal DIDS. The results suggest that the effects of amiloride and DIDS were polarized across the tracheal wall and involved epithelial and smooth muscle ion channels.

Contractile effects of nucleotides in guinea pig isolated, perfused trachea: involvement of respiratory epithelium, prostanoids and Na+ and Cl- channels.

ATP and UTP contracted guinea pig isolated, perfused trachea and were more potent when applied to the mucosal (intraluminal, IL) surface than when applied to the serosal (extraluminal, EL) surface. IL ATP and IL UTP were equipotent (ATP approximately UTP); EL ATP was 7-fold more potent than EL UTP (ATP > UTP). beta, gamma-Methylene ATP was nearly devoid of activity. Epithelium (Epi) removal decreased IL ATP potency and EL and IL maximum response magnitude, but elevated the IL UTP maximum response. In the presence of EL and IL indomethacin (3 x 10(-6) M; +/- Epi) to inhibit cyclo-oxygenase, or beta, gamma-methylene ATP (10(-4) M) to desensitize receptors, contractions to ATP were abolished, but those to UTP were not. Cl- channel blockade with 4,4'-diisothiocyano-2,2'-stilbene disulfonate (DIDS; 10(-4) M; +/- Epi) and sodium channel blockade with amiloride (10(-4) M; +/- Epi) antagonized contractions to EL and IL ATP and UTP. DIDS and amiloride did not inhibit contractions to methacholine; IL reactivity to methacholine was potentiated by indomethacin and Epi removal. Our findings indicate that the Epi facilitates contraction to ATP, which involves an atypical P2 purinoceptor, prostanoids, and Na+ and Cl- channels. Contractile responses to UTP involve a different receptor, and are neither facilitated by the Epi nor mediated by prostanoids, but involve these channels.

Relaxant effects of nucleotides in guinea pig isolated, perfused trachea: lack of involvement of prostanoids, Cl- channels and adenosine.

In higher concentrations (> 3 x 10(-4) M) than those causing contractile responses. ATP relaxed the smooth muscle of the guinea pig perfused trachea. Here we examined the relaxant effects of nucleotides. ATP and its nonhydrolyzable congener, beta, gamma-methylene ATP (APPCP), were approximately 4- and approximately 117-fold, respectively, more potent when applied separately to the serosal (extraluminal, EL) surface compared to the mucosal (intraluminal, IL) surface of methacholine (3 x 10(-7) M; EL)-contracted tracheae. APPCP was orders of magnitude more potent than ATP in both EL and IL compartments. EL UTP did not cause relaxation; IL UTP was nearly devoid of activity. The order of EL and IL activity (APPCP >> ATP) was unusual for nucleotide-induced relaxation of smooth muscle. Relaxation to ATP was not inhibited by the Cl- channel blocker 4,4'-diisothiocyano-2,2'-stilbene disulfonate (10(-4) M) or by the cyclo-oxygenase inhibitor indomethacin (3 x 10(-6) M), in contrast to the inhibitory effects of these drugs on contraction to ATP. The adenosine receptor antagonist 8-phenyltheophylline (10(-6) M) had no effect on relaxation to ATP or APPCP. Our findings indicate that Cl- channels, prostaglandins and adenosine are not involved in relaxation to adenine nucleotides.

Effects of intracerebroventricular captopril on angiotensin-converting enzyme and angiotensinogen mRNA levels in rat brain.

The effects of intracerebroventricular (i.c.v.) infusion of the angiotensin-converting enzyme (ACE) inhibitor captopril on angiotensin-induced drinking, brain ACE activity, and ACE and angiotensinogen (A-ogen) mRNA levels were examined. I.c.v. infusion of captopril at a rate of 1 microgram/microliter per h for 7 days resulted in a 60% reduction in brain ACE activity and an 80% reduction in the drinking response to i.c.v. angiotensin I. Quantitative solution hybridization experiments indicated that brain ACE mRNA levels were decreased by 40%, whereas brain A-ogen mRNA levels were unchanged. These results suggest that ACE and A-ogen mRNA levels are regulated differently in the brain than in the peripheral renin-angiotensin system.