Risk of allergic rhinitis in patients with inflammatory bowel disease: A systematic review and meta-analysis

BACKGROUND

Numerous parallels exist between inflammatory bowel disease (IBD) and allergic rhinitis (AR), which include risk factors (such as environmental and genetic factors), pathogenesis (immune disorders, epithelial cell barriers, etc.), and treatment (immunosuppressants and immunomodulators, such as cyclosporine and steroids). However, the risk of AR in IBD patients is unknown.

OBJECTIVE

In this systematic review and meta-analysis, patients with IBD are examined for their risk of AR.

METHODS

Several databases are accessible in both Chinese and English, including PubMed, BioRXiv, WanFang, the China National Knowledge Infrastructure (CNKI), Web of Science, METSTR, and MedRxiv. Findings presented at allergy, rhinology, thoracic, and gastrointestinal conferences were analyzed. Based on the inclusion and exclusion criteria, two evaluators independently retrieved data, read the literature, and evaluated bias risk. The data analysis was conducted using RevMan 5.4. Case-control and cohort studies were eligible study designs for this research.

RESULTS

There were 10 case-control studies and 1 cohort study included in the meta-analysis. The experimental group consisted of 65,687 IBD patients, of whom 5838 had AR. A total of 345,176 participants without IBD were included in the control group, of whom 24,625 developed AR. The outcomes demonstrated that IBD patients had a higher risk of developing AR (odds ratio [OR] = 1.48, 95% confidence interval [CI] [1.12, 1.95], Z = 2.78, P = 0.005) than those without IBD.

CONCLUSION

The risk of AR is higher in IBD patients. Further investigation is required to determine the mechanism behind the association between AR and IBD.

Quality Evaluation of Volatile Oil in Yanyangke Mixture (YM) Based on GC-MS Fingerprint, GC Multicomponent Quantitative Analysis and Chemical Pattern Recognition Analysis

Yanyangke mixture (YM) is composed of 12 kinds of traditional Chinese medicine (TCM) used for the treatment of patients with cough, dry throat and other diseases caused by acute or chronic pharyngitis or patients with difficulty in expectoration. With the wide application of YM in clinical practice, its quality control has attracted huge attention. Based on the multi-component characteristics of Chinese herbal medicines, it is pertinent to establish a quality evaluation system. A new idea is to adopt gas chromatography-mass spectrometry (GC-MS) chemical composition identification, GC-MS fingerprint, and GC content determination as a potential quality control index of the volatile oil in YM. In this study, the volatile oil of YM was extracted by steam distillation, and the chemical components of the volatile oil were analyzed by GC-MS, and 43 chemical components were identified. The fingerprint of the volatile oil from YM was established and the similarity evaluation was performed. Combined with chemometric methods, such as cluster analysis, principal component analysis and partial least squares analysis, the chemical composition differences of the volatile oil from different batches of YM were compared and the symbolic components affecting the quality of the volatile oil from different batches of YM were excavated. Finally, three components were selected as the potential active component markers of YM and the GC content determination method of these three components was established. A rapid, reasonable, and effective quality evaluation and control method of YM volatile oil was established, which provided a reference for further development and research on YM, as well as a new idea for research on other TCM prescriptions.

The association between 5-HT1A binding and temporal lobe epilepsy: A meta-analysis of molecular imaging studies

BACKGROUND

Studies have shown conflicting results in the correlation between serotonin-1A (5-HT1A) receptor binding levels in the brain and temporal lobe epilepsy (TLE). There is a need to systematically evaluate the correlation between the 5-HT1A binding level and TLE from the perspective of the brain using molecular imaging.

METHODS

Chinese and English databases, such as the China National Knowledge Infrastructure (CNKI), the China Science and Technology Journal Database (VIP), WanFang, the Chinese Biomedical Literature Service System (SinoMed), PubMed and Web of Science, were searched.

RESULTS

Two evaluators independently screened the literature, extracted data, and evaluated the risk of bias in the included studies according to the inclusion and exclusion criteria. RevMan 5.4.1 was used to analyze the data. A total of 196 participants were included; of these, 95 had TLE and 131 were healthy controls who had never had a seizure before participating in the study. Meta-analysis results suggested that 1) decreased 5-HT1A binding was found on the affected side of patients with TLE (standard mean difference (SMD) = -1.45, 95% confidence interval (CI) [-2.27, -0.64], Z = 3.48, P = 0.0005); 2) decreased 5-HT1A binding was found in the ipsilateral hippocampus of patients with TLE (SMD = -1.76, 95% CI [-2.51, -1.00], Z = 4.57, P＜0.00001); 3) decreased 5-HT1A binding was found in the ipsilateral temporal lobe cortex of patients with TLE (SMD = -0.46, 95% CI [-0.80, -0.12], Z = 2.66, P = 0.008); 4) decreased 5-HT1A binding was found in the ipsilateral amygdala in patients with TLE (SMD = -1.36, 95% CI [-2.48, -0.23], Z = 2.37, P = 0.02); and 5) decreased 5-HT1A binding was found in the frontal lobe of patients with TLE(SMD = -0.75, 95% CI [-1.29, -0.20], Z = 2.67, P = 0.008).

CONCLUSION

A reduction in 5-HT1A binding in the hippocampus, temporal cortex, amygdala, and frontal lobe was observed on the affected side of patients with TLE. The decrease in 5-HT1A binding can be considered related to TLE. Potentially relevant factors should be considered in future molecular imaging studies.

Is depression in patients with temporal lobe epilepsy related to hippocampal sclerosis? A meta-analysis

OBJECTIVE

To systematically evaluate the association between hippocampal sclerosis (HS) and depression in patients with temporal lobe epilepsy (TLE) through a meta-analysis.

METHODS

Chinese and English databases, such as the China National Knowledge Infrastructure (CNKI), Chinese Scientific Journals (VIP), WanFang, the Chinese Biomedical Literature Service System (SinoMed), PubMed and the Web of Science, were searched.

RESULTS

Two evaluators independently screened the literature, extracted data and evaluated the risk of bias in the included studies in accordance with the inclusion and exclusion criteria. RevMan 5.1 was used to analyze the data. A total of 786 patients with epilepsy were included in the study, including 82 depressive patients with HS and 64 depressive patients without HS. The results showed that the TLE patients with HS were more likely to develop depression than those without HS (odds ratio (OR)= 2.14, 95% confidence interval (CI) [1.45, 3.16], Z = 3.85, p = 0.0001).

CONCLUSION

HS can be considered a high-risk factor for depression in patients with TLE, and the correlation is significant. However, the sample size included in the study was small; additional high-quality studies are needed in the future.

Maternal anti-HBVs suppress the immune response of infants to hepatitis B vaccine

It is still controversial whether maternal anti-HBV antibodies (anti-HBVs) affect the infants' immune response to hepatitis B virus (HBV) vaccination. This multicentre study aims to address this question. First, we determined whether the transplacental transfer of maternal anti-HBVs occurs by measuring the titres of 90 anti-HBVs-positive pregnant women and their newborns. The anti-HBVs-positive rates of newborns ranged from 89.7% to 100.0%, depending on the maternal anti-HBVs titres. Secondly, we investigated the effects of maternal anti-HBVs on the immune response of infants to HBV vaccination. A total of 1063 mother-and-infant pairs were enrolled and divided into three groups with maternal anti-HBVs titres of <10 IU/L (negative - 37.9%), 10-499 and ≥500 IU/L. The infants' anti-HBVs-positive rate and titres were negatively correlated with maternal anti-HBVs titres: the anti-HBVs-positive rate of infants were 88.9% (360/405), 84.5% (381/451) and 77.3% (160/207) in mothers with low, intermediate and high antibody titres, respectively, P<.0001. Median titres of anti-HBVs (IU/L) among infants were 169.1, 141.0 and 79.4, respectively, P=.020. One hundred and sixty-two infants were negative for anti-HBVs after the standard vaccination, and 120 of 131 of these infants (91.6%) reached anti-HBVs positivity after the first "booster" dose. The maternal anti-HBVs titres did not significantly affect infant response to this booster. In summary, transplacental transfer of anti-HBVs occurs and high titres of maternal anti-HBVs may suppress the immune response of infants to the standard HBV vaccination. The current schedule of the 0, 1 and 6 month may not be the optimal choice of infants with anti-HBVs-positive mothers.

White Matter Development is Potentially Influenced in Adolescents with Vertically Transmitted HIV Infections: A Tract-Based Spatial Statistics Study

BACKGROUND AND PURPOSE

Convergent evidence indicates that HIV is associated with abnormal WM microstructure in adults. However, little is known about whether HIV affects WM development in adolescents. In this study, we used DTI to investigate the integrity of WM microstructure in adolescents with vertically transmitted HIV infections.

MATERIALS AND METHODS

Fifteen HIV-positive adolescents with vertically transmitted infections and 26 HIV-negative controls participated in this study. Whole-brain analysis of fractional anisotropy was performed by Tract-Based Spatial Statistics to localize abnormal WM regions between groups. VOI analysis was further performed to explore the changes in diffusivity indices in the regions with fractional anisotropy alterations. Correlation analyses were used to assess the relationship between fractional anisotropy alterations and clinical measures within the HIV-positive group.

RESULTS

Relative to HIV-negative controls, HIV-positive adolescents demonstrated significantly reduced fractional anisotropy in the corpus callosum, superior and posterior corona radiata, frontal and parietal WM, pre-/postcentral gyrus, and superior longitudinal fasciculus. In the affected regions, fractional anisotropy reductions were caused by an increase in radial diffusivity, and no changes were observed in axial diffusivity. Moreover, fractional anisotropy values in the bilateral frontal WM were negatively correlated with the duration of highly active antiretroviral therapy and were positively associated with the age at onset of highly active antiretroviral therapy.

CONCLUSIONS

These findings suggest that early HIV infections may affect WM development, especially in the frontal WM, corpus callosum, and corona radiata in adolescents, which may be associated with hypomyelination and demyelination. Moreover, WM integrity may serve as a potential new treatment target.

Ileocaecal junction carcinoma: a clinicopathological study of 199 cases

AIM

The ileocaecal junction (ICJ) region is an epithelial transition zone in which carcinomas are frequently diagnosed. However, it is currently unknown whether ICJ carcinomas (ICJ-CAs) have distinctive features. This study aimed to characterize the clinicopathological features of ICJ-CAs.

METHOD

All ileal and colorectal resections for carcinoma, performed in Calgary, Canada between January 2009 and June 2012, were reviewed. Carcinomas in which the epicentre was within 5 cm of the ileocaecal valve (ICV) were defined as ICJ-CAs. Of 1003 carcinomas studied, 199 (19.8%) were ICJ-CAs, including 93 (9.3%) that crossed the ICV. Comparison of clinicopathological features with carcinomas of the other ileo-colorectal regions was made. Survival was also assessed.

RESULTS

Clinically, ICJ-CAs were more common in female than male patients (56.3% female) compared with left-colonic (42.9% female) and rectal (37.9% female) carcinomas, and were more common in older age-groups of patients (71.8 ± 12.7 years) compared with appendiceal (62.6 ± 11.3 years), left-colonic (69.4 ± 12.3 years) and rectal (67.1 ± 11.9 years) carcinomas. Macroscopically, ICJ-CAs were similar to other colorectal carcinomas and were mostly described as ulcerated (63.3%). Histologically, ICJ-CAs had more mucinous, signet-ring cell and/or neuroendocrine features (39.7%, 8.0% and 7.5%, respectively) than did carcinomas of the left colon (16.8%, 1.6% and 1.1%, respectively) and the rectum (14.1%, 1.0% and 0.0%, respectively). They were higher grade (20.1% were high grade) than those of the left-colon (10.3%) and the rectum (9.8%). ICJ-CAs presented at a higher T-stage (25.6% were T4) compared with rectal carcinomas (11.6%). Most significantly, ICJ-CAs presented at a higher N-stage (25.6% were N2) than did right-colonic (14.1%) and rectal (16.2%) carcinomas. Although survival of patients with ICJ-CAs did not differ from those with right-colonic carcinomas, those with carcinomas directly involving the ICV did show a significantly decreased survival.

CONCLUSION

ICJ-CAs display several distinct clinicopathological features that may require special diagnostic, prognostic and management attention.

Endogenous neurotensin facilitates visceral nociception and is required for stress-induced antinociception in mice and rats

Central neurotensin (NT) administration can both facilitate and inhibit somatic and visceral nociception, depending on the dose and administration site. NT microinjection in the rostroventral medulla facilitates nociception at low doses, while NT antagonist microinjection can markedly attenuate nociception, supporting the hypothesis that endogenous NT facilitates nociception. However, higher doses of NT produce a mu-opioid receptor-independent analgesia, similar to that resulting from various intense stressors. Furthermore, intense stress results in increased NT expression in several hypothalamic nuclei that have been implicated in stress-induced antinociception (SIAN); however, there is little direct evidence that endogenous NT is required for SIAN. We have investigated the role of endogenous NT in both basal visceral nociception and SIAN using both NT knockout mice and pharmacological approaches in rats. Visceral nociception was monitored by measuring visceromotor responses during colorectal distension both prior to and following water avoidance stress. Visceral nociception was significantly attenuated in both NT knockout mice and rats pre-treated with the NT antagonist SR 48692. Disruption of NT signaling also blocked SIAN, revealing a novel stress-induced hyperalgesic response that was significantly greater in female than in male rats. NT was also required for acetic acid-induced hyperalgesia. These results indicate that endogenous NT normally facilitates visceral pain responses, is required for irritant-induced hyperalgesia, and plays a critical role in SIAN.

Endogenous neurotensin facilitates enterohepatic bile acid circulation by enhancing intestinal uptake in rats

Initial studies on the digestive hormone neurotensin (NT) showing that intestinal NT mRNA expression and blood levels were altered in rats fed chow containing bile acid (BA) and the BA chelator cholestyramine led us to investigate the role of NT in the enterohepatic circulation of BA. In fasted, anesthetized rats with common bile ducts cannulated for bile collection, intravenous NT infusion (10 pmol. kg(-1). min(-1)) enhanced BA output relative to control over 3 h in animals administered donor bile into the duodenum (30 microl/min). This suggested that the effect of NT was on the return of BA from the intestine to the liver, which is rate determining in the normal process. In rats prepared as described above and administered [(3)H]taurocholate ([(3)H]TC; 5 mM, 1 ml) duodenally, NT infusion (3-10 pmol x kg(-1) x min(-1)) increased the [(3)H]TC recovery rate in bile approximately twofold, whereas sulfated CCK-8 (12-50 pmol x kg(-1) x min(-1)) had no effect. To investigate the roles of endogenous NT and CCK, we administered [(3)H]TC into the rat duodenum or lower jejunum and tested the effect of the NT antagonist SR-48692 (2 nmol x kg(-1) x min(-1)) or CCK-A antagonist lorglumide (100 nmol x kg(-1) x min(-1)). SR-48692 reduced the [(3)H]TC recovery rate by congruent with 50% and congruent with 24% in the duodenum and jejunum, respectively, whereas lorglumide had no effect. These results suggest that NT or a similar peptide is an endogenous regulator of enterohepatic BA cycling, which acts by enhancing BA uptake in the intestine.

Epidemiological investigation of Histoplasma capsulatum infection in China

OBJECTIVE

To provide reliable information concerning the presence or the absence of Histoplasma capsulatum (H. capsulatum) infection in China, and data concerning this respect.

METHODS

Three hundred normal people and 435 hospitalized patients, who lived in Hunan and Jiangsu provinces, and the Xinjiang Autonomous Region, were tested with yeast-phase histoplasmin (ALK/Berkerley Biologicals Laboratories, USA) and human pure protein derivative of tuberculin (PPD) on the volar surface of the forearm. Any reaction to the antigens over 5.0 mm in diameter of induration at 48-72 hours was considered positive.

RESULTS

A total of 138 subjects (18.8%) in 735 patients reacted to histoplasmin with 5.0-45.0 (9.1 +/- 4.3) mm indurations. Significant differences of positive skin reaction rates in normal subjects were found in Hunan, Jiangsu and Xinjiang (8.9% vs 15.1% vs 2.1%). The overall positive rate of patients was 25.5%. Patients with tuberculosis [31.7% (78/246)] had a significantly higher positive skin reaction rate in comparison with those suffering from pneumonia [17.7% (11/62)], lung cancer [20.9% (9/43)], chronic obstructive pulmonary disease [17.3% (9/52)] and other diseases [12.5% (4/32)] (P < 0.01). Of 562 cases, 292 cases (52.0%) reacted to PPD with indurations of 5-50 (13.7 +/- 4.9) mm in diameter, 63 cases (11.2%) reacted to both histoplasmin and PPD, while 38 cases (6.9%) reacted to histoplasmin but not to PPD.

CONCLUSIONS

The data suggest that there is H. capsulatum herd infection in China. The infection rate in Southeast China is higher than that in the Northwest, and the infection rate of patients with pulmonary tuberculosis is higher than that of normal persons and other pneumonopathy patients.

[A study on the resistance of Staphylococcus aureus and the mechanisms of its resistance to fluoroquinolone]

OBJECTIVE

To investigate the resistance of Staphylococcus aureus(SA) and the mechanisms of its resistance to fluoroquinolones (FQ).

METHODS

The susceptibility of SA (200 strains) to 12 antibiotics was detected by disc diffusion, The minimal inhibitory concentrations (MICs) of 52 strains to three FQ were determined by agar dilution method. 52 strains resistant to ciprofloxacin (MIC> or =4 mg/L) were studied for the presence of point mutations in the gyrA gene and grlA gene by polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP) method and for the expression of norA gene by reserpine reverse test respectively.

RESULTS

34% of the strains were resistant to oxacillin(methicillin resistant Staphylococcus aureus, MRSA) and other antimicrobials as well, but no vancomycin resistant strain was found. The resistance rate of MRSA to ciprofloxacin was 79.4% and cross-resistance existed. It was found that 42 strains (80.8%) had a mutation at gyrA codon 84 (TCA-->TTA or GCA). Mutations at grlA codon 80 (TCC-->TAC or TTC) and codon 84 (GAA-->AAA)were observed in 10 (19.2%) and 14 strains(26.9%) respectively.Strains containing mutations in gyrA or both gyrA and grlA gene showed a higher level of ciprofloxacin resistance than those with alternation in grlA gene but with wild type gyrA or non-gyrA mutants (P < 0.01). Decreased MICs to ciprofloxacin, norfloxacin and levofloxacin in reserpine reverse test indicated the presence of norA phenotype.

CONCLUSIONS

It is clear that emergence of resistant SA strains will continue to be a problem, especially in MRSA which was resistant to most of the antibiotics. Fluoroquinolones are not the choice for MRSA now. The resistance to fluoroquinolones in clinical isolates of SA are due to the mutations of the gyrA and grlA gene encoding the target enzyme of fluoroquinolones and cell membrane resistance. Mutations of grlA gene may differ in different districts.

Enhancement of jejunal absorption of conjugated bile acid by neurotensin in rats

BACKGROUND & AIMS

Release of neurotensin (NT) from intestines is markedly stimulated by ingested fat, and NT may facilitate lipid digestion and absorption through various actions that are not fully understood. Our recent finding that NT stimulates hepatic output of bile acids only when bile delivery to the intestine is maintained has led us to investigate the effects of NT on bile acid absorption in the rat small intestine.

METHODS

We measured the effects of intravenous infusion of NT (3-10 pmol x kg(-1) x min(-1)) on biliary recovery of (3)H-taurocholate ((3)H-TC) and (3)H-cholate administered into proximal and distal intestines or into isolated intestinal segments in situ in biliary fistula rats. To further understand the underlying mechanisms involved, the effects of NT on intestinal absorption of (3)H-D-glucose, (3)H-leucine, (14)C-antipyrine, and (51)Cr-EDTA were investigated by monitoring the absorption of radioactivity into superior mesenteric venous blood.

RESULTS

Infusion of NT, at doses that caused near physiologic increases in blood NT levels, increased biliary recovery of (3)H-TC from the jejunum (3.4-fold) and ileum (1.7-fold), but did not enhance absorption of (3)H-cholate. NT also facilitated transcellular uptake of (3)H-glucose and (3)H-leucine and increased paracellular uptake to (51)Cr-EDTA and (3)H-mannitol, but did not alter the absorption rate for (14)C-antipyrine.

CONCLUSIONS

These results indicate that NT can exert a facilitative effect on intestinal bile acid absorption and return to liver. This effect of NT may involve increases in paracellular absorption and carrier-mediated transport by mechanisms not yet identified.

Neurotensin elevates hepatic bile acid secretion in chickens by a mechanism requiring an intact enterohepatic circulation

Neurotensin (NT), given intravenously at 10-50 pmol/kg per min to anesthetized female chickens equipped with a bile duct fistula, dose-dependently elevated hepatic bile flow and bile acid output but only when the enterohepatic circulation was maintained by returning the bile to the intestinal lumen. Infusion of NT at 10 and 50 pmol/kg per min increased the average hepatic bile acid output over a 30-min period to 138 +/- 11 and 188 +/- 13% of control, respectively. During infusion of NT, plasma levels of immunoreactive NT (iNT) increased in time from the basal level (14 +/- 1.3 pM) to reach steady state at 30 min. There was a near linear relationship between the dose of NT infused and the increment in plasma iNT. In addition, infusion of NT at 40 pmol/kg min gave a plasma level of iNT (approximately/= 88 pM) which was within the range of those observed during duodenal perfusion with lipid (54-300 pM) and near to that measured in hepatic portal blood from fed animals (52 +/- 5 pM). Perfusion of duodenum with lipid released endogenous NT and increased the rate of hepatic bile flow. When NT antagonist SR48692 was given, bile flow rate decreased to the basal level. These results suggest that intestinal NT, released by lipid, may participate in the regulation of hepatic bile acid output by a mechanism requiring an intact enterohepatic circulation.

[Clinical analysis of 96 cases with pulmonary disease caused by nontuberculous mycobacteria]

OBJECTIVE

To study the clinical characteristics of nontuberculous mycobacteria (NTM) pulmonary disease.

METHODS

Ninety-six out of 173 cases with NTM pulmonary disease diagnosed through identification of mycobacterium strains isolated from 5,592 sputum acid-fast staining positive cases from 1981-1996 were selected, and a retrospective analysis was made.

RESULTS

According to Runyon classification, there were 14 cases with M. kansasii and 1 with M. marinum in type I, 4 with M. scrofulsceum in type II, 23 with M. intracellulare or M. avium in type III, 24 with M. chelonae and 30 with M. fortuitumin in type IV. Cases whose courses of disease were more than 10 years accounted for 31%. Main clinical symptoms included cough (78%), expectoration (71%), haemoptysis (58%) and fever (26%). Fifty-seven percent cases in X-ray chest film were seen lesions bilaterally, 42% in one side, 27% in the right and 15% in the left. One percent showed no obvious lesion in X-ray chest film. Excluding one case with incomplete data, the total resistance rate of NTM was 96% in other 95 cases, 93% in type I, 50%, 100% and 100% in type II, III, IV respectively. After antituberculous chemotherapy, sputum negative conversion was seen in 14 of 15 cases with type I NTM, 6 of 23 with type III and 14 of 54 with type IV, while definite data in 4 cases with type II were not available.

CONCLUSIONS

NTM pulmonary disease is characterized by long course of disease, nonspecific symptoms, high resistance rate and unsatisfactory therapeutic efficacy.

[Influence of processing methods on alkaloid, toxicity and effect of Strychnos nux-vomica L]

Determination has been made on the contents of strychnine, brucine and ephedrin in different processed products of Strychnos nux-vomica. The acute toxicity, analgesic and antiphlogistic actions of these products have also been detected. The result shows that the product processed with Ephedra sinica can reduce toxicity and promote curative effect. Among the different processing methods the preparation with Ephedra and Liqorice root and the preparation with Ephedra and alcohol appear better and thus useful in practical application.

[Potential role of gut peptides in stress-induced colonic motor disorder]

OBJECTIVE

To explore the potential role of gut peptide in stress-induced colonic motor disorder.

METHODS

In 9 conscious Wistar rats pre-equipped with strain-gauge transducers on ascending and descending colon, colonic motility was recorded before, during and after stress. And colonic transit was evaluated by instilling Cr into the cecum through chronically implanted cannula in each group of 16 rats with or without stress, and then calculating the geometric center (GC) of radioactivity. The contents of VIP, SP, NT, SST, MOT and Leu-ENK in plasma, colonic mucosa and muscle layer were assessed in 16 stressed and 16 control rats. Exogenous peptides (VIP, SP, SST, NT) were intravenously administered in 9 rats to determine the colonic motor response. Also, the effects of peptides on colonic circular muscle strips were investigated.

RESULTS

Motor activity was increased after stress, whereas colonic transit was delayed. In the stressed rats, plasma levels of VIP and Leu-ENK were higher than those in controls. The content of Leu-ENK in muscle tissue decreased. Both in vivo and in vitro studies showed that SP and NT excited, whereas VIP and SST inhibited colonic motor activity.

CONCLUSION

Release of certain peptides is altered by stress. Increased release of ENK and VIP may be involved in stress-induced colonic motor disorder and in the regulation of "stress hormone" release.

Effect of sevoflurane on hypoxic pulmonary vasoconstriction in the perfused rabbit lung

BACKGROUND

In vitro studies have shown that isoflurane, enflurane, and halothane inhibit the hypoxic pulmonary vasoconstriction (HPV) with essentially the same potency. The aim of this study is to compare the effects of sevoflurane and isoflurane on HPV in constant-flow perfused rabbit lungs.

METHODS

Constant-flow perfused lungs from Japanese white rabbits were tested. The lungs were divided into three groups: isoflurane alone (n = 6), sevoflurane alone (n = 6), and sevoflurane with ibuprofen pretreatment (n = 6). Baseline HPV responses were measured as the pulmonary arterial pressure increased after changing inspired oxygen concentration from 95% for 15 min to 3% (with 5% CO2) for 5 min without anesthetic administration. Next, three different concentrations of anesthetics were added to the inspired gas for 15 min in random order. The HPV response in the presence of anesthetic was expressed as a percentage of the pressor response in the absence of anesthetics, and dose-response relationships were calculated using the nonlinear least-squares method.

RESULTS

Isoflurane and sevoflurane both depressed the HPV response in a dose-related manner. The half-inhibition values (ED50) of HPV with isoflurane and sevoflurane were 0.85 +/- 0.22 MAC and 1.00 +/- 0.12 MAC (mean +/- SD), respectively, and were not statistically different. Ibuprofen pretreatment did not alter ED50 and slope of dose-response curve, although the absolute value of pressor response in the sevoflurane group with ibuprofen pretreatment was greater than that in the sevoflurane alone group at every concentration of sevoflurane.

CONCLUSIONS

Sevoflurane inhibits the HPV response in a dose-related manner, and its potency is similar to that of isoflurane in vitro. Cyclooxygenase products do not mediate the inhibition of HPV by sevoflurane.

Effect of cyclosporin A on murine natural killer cells

In mice, cyclosporin A decreased the natural killer cell-enhancing effect of two interferon inducers, infective murine cytomegalovirus and nonreplicating Newcastle disease virus. It also inhibited murine cytomegalovirus replication at doses greater than 20 mg/kg, but it did not significantly inhibit interferon induction by Newcastle disease virus. In cell culture, cyclosporin A had no direct effect on the natural killer activity of spleen mononuclear cells derived from normal or murine cytomegalovirus-infected animals. However, at 50 micrograms/ml it significantly reduced the ability of interferon to enhance the natural killer activity of normal spleen cell suspensions. The inhibitory effect of cyclosporin A on natural killer cell activity in infected mice may be partly explained by its ability to block the action of interferon.