Long-Term Outcomes of Stereotactic Body Radiation Therapy with or without PD-1 Inhibitors in Metastatic Nasopharyngeal Carcinoma

PURPOSE/OBJECTIVE(S)

Data on the benefit of stereotactic body radiation therapy (SBRT) in patients with metastatic nasopharyngeal carcinoma (mNPC) remain limited. The purpose of this study is to assess the outcomes of mNPC treated with SBRT and programmed death-ligand 1 (PD-1) inhibitors.

MATERIALS/METHODS

We reviewed all SBRT performed in patients with mNPC during the period of 2013-2022 in our institution. Treatments carried out with ablative intent in stereotactic conditions with dose/fraction ≥ 5 Gy were considered. The local control (LC), overall survival (OS), and progression-free survival (PFS) rates were calculated using Kaplan-Meier analyses. Risk factors were assessed through univariate and multivariate analysis by Cox regression.

RESULTS

A total of 55 patients with 77 metastatic lesions treated with SBRT were analyzed. All of these patients received systemic treatment, either chemotherapy alone (n = 34) or chemotherapy with PD-1 inhibitors (n = 21). 28 patients (50.9%) had ≤ five metastatic lesions in the metastatic sites. The number of irradiated tumors ranged from 1 to 6, and 36 patients (65.5%) with 47 lesions received a physical dose ≥48 Gy (BED≥75Gy, α/β = 10). After a median follow-up of 43.6 months (range 1.9-115.3 months), 20 patients (36.4%) experienced local recurrence after completion of SBRT for metastatic lesions. The 1- and 3-year LC rates were 76.9% and 61.9%, respectively. The 1- and 3-year OS rates were 84.4% and 58.2%, and the 1- and 3-year PFS rates were 50.0% and 29.9%, respectively. Patients with ≤ 2 metastatic lesions (n = 24, 43.6%) had significant better LC (HR 0.11, 95% CI 0.036-0.313, p<0.001), OS (HR 0.24, 95% CI 0.08-0.74, p = 0.013) and PFS (HR 0.16, 95% CI 0.063-0.42, p<0.001) than patients with>2 metastatic lesions. Total dose≥48 Gy was also found to be a significant prognostic factor for better OS (HR 0.44, 95% CI 0.18-1.09, p = 0.044) and PFS (HR 0.42, 95% CI 0.17-0.88, p = 0.005), but not LC (HR 0.84, 95% CI 0.36-1.97, p = 0.678). In addition, adding PD-1 inhibitors to SBRT showed a significant benefit, improving the 2-year LC to 87.7% vs. 50.6% for SBRT (HR 0.27, 95% CI 0.18 - 0.41, p = 0.002). No patients experienced grade 4 or 5 toxicity.

CONCLUSION

SBRT is an effective and safe treatment option for mNPC patients. Adding PD-1 inhibitors to SBRT offers a benefit in LC. Additional studies exploring the clinical benefit and predictive biomarkers of combined SBRT and PD-1 directed immunotherapy are warranted.

Tumor Treatment Response Assessed During the Concurrent Chemoradiotherapy for Nasopharyngeal Patients

PURPOSE/OBJECTIVE(S)

To evaluate intratumoral treatment response distribution with using FDG-PET/CT during the chemoradiotherapy of nasopharyngeal patients (NPC).

MATERIALS/METHODS

A total of 5 of 30 patients with stage III-IVA NPC were enrolled in the institutional protocol for induction/concurrent chemoradiotherapy with radiation dose of 70 Gy in 33 fractions. For each patient, a pre-radiation treatment FDG-PET/MRI image (SUV0) and a mid-treatment image (SUVm) at the treatment dose of 31.8 Gy were obtained. Followed by deformable PET/MRI registration between SUV0 and SUVm, the tumor voxel SUV reduction ratio was obtained to construct a tumor dose response matrix (DRM). Tumor SUVavid was also constructed by limiting tumor voxel SUVm > a given value. Spatial correlations of the tumor SUV0, SUVm, SUVavid and DRM were determined.

RESULTS

The mean and coefficient variation (CV) of the SUV0, SUVm and DRM for all tumors were 5.05 (52%), 2.72 (49%) and 0.64 (63%) (Table contains the individual data), which were smaller than those on the SUVs of head-n-neck HPV+ patients reported previously due to the induction chemotherapy, but had much larger DRM mean and CV. The inter-tumoral CVs of SUV0 and DRM were 29% and 27%, which were much lower than those of the intra-tumoral CVs 43% and 57%. Meanwhile, the intra-tumoral variations on SUV0 was smaller than the one of head-neck HPV+ patients, but the DRM intra-variation was much larger. There was a weak correlation between SUV0 and SUVm with the correlation coefficient 0.13, a medium correlation of -0.55 between SUV0 and DRM, but a strong correlation, 0.72, between SUVm and DRM. However, the spatial correlation between tumor DRM and SUVavid was getting weaker as the SUVavid value increasing and equal 0.47 with SUVavid value > 3.

CONCLUSION

The spatial dose response DRM for NPC in the concurrent chemoradiotherapy was relatively high, while had relatively low baseline tumor metabolic activity SUV0. It was most likely due to the induction chemotherapy. In addition, the tumor dose response showed vary large intra-tumoral variation. The high correlations between DRM and SUVm imply that SUVavid could be used partially to guide adaptive modification of NPC treatment with carefully selected boundary value.

[Examining fermented mustard brine in terms of traditional Chinese medicine]

Fermented mustard brine was a unique liquid fermented with mustard long used in traditional Chinese medicine. It was previously known as Ji Shui, which refered to the yellow salty water after vegetables were fermented. Fermented mustard brine was not established in TCM until the Ming Dynasty. It was found that the original plant of ancient mustard was Brassica juncea (L.) Czern et Coss. var. juncea, and the origin of the mustard used in mustard brine mainly refereed to the cultivated species of Brassica (Brassica juncea var. multiceps Tsen et Lee) in the Brassica branch of the Cruciferae family, which belonged to the mustard leaf class in tillering mustard. Fermented mustard brine tasted spicy and salty and was considered as a feature of cold, and went to the lung meridian. Its effects were of clearing heat and reducing phlegm, calming coughing and expelling pus. It was mainly used for the treatment of lung carbuncle, and also for diseases such as lung impotence, laryngeal tinea, wheezing, coughing, vomiting pus and blood, and facial swelling. The ways to use it involved taking it directly (or taking it warm), taking it with hot soybean milk, having it with food, mixing it with decoction, and mixing it with houttuynia cordata juice. It was mainly produced in the Jiaxing area of Zhejiang province, especially famous for the collection by the Tianning Temple in Tianning in Jiashan, not the Tianning Temple in Changzhou.

[Application of augmented reality and mixed reality navigation technology in laparoscopic limited right hepatectomy]

Objective: To investigate the application effect of augmented reality and mixed reality navigation technology in three-dimensional(3D) laparoscopic narrow right hepatectomy(LRH). Methods: A retrospective analysis was performed on the clinical data of 5 patients with hepatic malignancy admitted to the First Department of Hepatobiliary Surgery,Zhujiang Hospital,Southern Medical University from September 2020 to June 2021,all of whom were males,aged from 42 to 74 years.Preoperative evaluation was performed using the self-developed 3D abdominal medical image visualization system; if all the 5 patients were to receive right hemihepatectomy,the remnant liver volume would be insufficient,so LRH were planned.During the operation,the independently developed 3D laparoscopic augmented reality and mixed reality surgical navigation system was used to perform real-time multi-modal image fusion and interaction between the preoperative 3D model and 3D laparoscopic scene.Meanwhile,intraoperative ultrasound assisted indocyanine green fluorescence was used to determine the surgical path.In this way,the LRH under the guidance of augmented reality and mixed reality navigation was completed.The predicted liver resection volume was evaluated before surgery,actual resected liver volume,surgical indicators and postoperative complications were analyzed. Results: All the 5 patients completed LRH under the guidance of augmented reality and mixed reality navigation technology,with no conversion to laparotomy.The median operative time was 300 minutes(range:270 to 360 minutes),no intraoperative blood transfusion was performed,and the median postoperative hospital stay was 8 days(range:7 to 9 days).There were no perioperative deaths,or postoperative complications such as liver failure,bleeding,or biliary fistula. Conclusion: For patients who need to undergo LRH,the use of augmented and mixed reality navigation technology can safely and effectively guide the implementation of surgery,retain more functional liver volume,improve surgical safety,and reduce postoperative complications.

Fluxes of Atmospheric Greenhouse-Gases in Maryland (FLAGG-MD): Emissions of Carbon Dioxide in the Baltimore, MD-Washington, D.C. area

To study emissions of CO2 in the Baltimore, MD-Washington, D.C. (Balt-Wash) area, an aircraft campaign was conducted in February 2015, as part of the FLAGG-MD (Fluxes of Atmospheric Greenhouse-Gases in Maryland) project. During the campaign, elevated mole fractions of CO2 were observed downwind of the urban center and local power plants. Upwind flight data and HYSPLIT (Hybrid Single Particle Lagrangian Integrated Trajectory) model analyses help account for the impact of emissions outside the Balt-Wash area. The accuracy, precision, and sensitivity of CO2 emissions estimates based on the mass balance approach were assessed for both power plants and cities. Our estimates of CO2 emissions from two local power plants agree well with their CEMS (Continuous Emissions Monitoring Systems) records. For the 16 power plant plumes captured by the aircraft, the mean percentage difference of CO2 emissions was -0.3 %. For the Balt-Wash area as a whole, the 1σ CO2 emission rate uncertainty for any individual aircraft-based mass balance approach experiment was ±38 %. Treating the mass balance experiments, which were repeated seven times within nine days, as individual quantifications of the Balt-Wash CO2 emissions, the estimation uncertainty was ±16 % (standard error of the mean at 95% CL). Our aircraft-based estimate was compared to various bottom-up fossil fuel CO2 (FFCO2) emission inventories. Based on the FLAGG-MD aircraft observations, we estimate 1.9±0.3 MtC of FFCO2 from the Balt-Wash area during the month of February 2015. The mean estimate of FFCO2 from the four bottom-up models was 2.2±0.3 MtC.

[Application of augmented-reality surgical navigation technology combined with ICG molecular fluorescence imaging in laparoscopic hepatectomy]

Objective: To study the application value of augmented-reality (AR) surgical navigation technology combined with indocyanine green (ICG) molecular fluorescence imaging in three-dimensional (3D) laparoscopic hepatectomy. Methods: The clinical data of forty-eight patients who had undergone 3D laparoscopic hepatectomy for hepatocellular carcinoma at First Department of Hepatobiliary Surgery, Zhujiang Hospital, Southern Medical University from January 2018 to April 2019 were retrospectively analyzed.The patients were divided into two groups: the group of 3D laparoscopic hepatectomy navigated by augment reality technology combined with ICG molecular fluorescence imaging (Group A) , and group of conventional 3D laparoscopic hepatectomy (Group B) . Patients in Group A (n=23) underwent 3D laparoscopic hepatectomy using augmented-reality technology combined with ICG molecular fluorescence imaging. In this group, the self-developed three-dimensional laparoscopic augmented-reality surgical navigation system (No. 2018SR840555) was operated to project the preoperative three-dimensional model to the surgical field, and the use of this system in combination with ICG molecular fluorescence imaging navigated laparoscopic hepatectomy. No surgical navigation technology was applied in Group B (n=25) . All patients signed the informed consent, which were in accordance with the requirements of medical ethics (Ethics No.: 2018-GDYK-003) . The preoperative data, surgical indicators and postoperative complications between the two groups were compared and analyzed. Results: The median amount of intraoperative blood loss of Group A was 250 (200) ml (M (Q(R)) ) , which was significantly lower than that of Group B (300 (150) ml) (Z=-2.307, P=0.021) .The transfusion rate of Group A was 13.0% (3/23) , which was significantly lower than that of Group B (40.0%, 10/25) (χ(2)=4.408, P=0.036) .The median postoperative hospitalization time of Group A was 8 (2) d, which was significantly shorter than that of Group B (11 (6.5) d) (Z=-2.694, P=0.007) . There were no serious complications and perioperative death in both groups.The incidence of postoperative complications in Group A was 17.4% (4/23) , which was not significantly different from that in group B (28%, 7/25) (χ(2)=0.763, P=0.382) . Conclusion: Augmented-reality surgical navigation technology combined with ICG molecular fluorescence imaging has better effect in 3D laparoscopic hepatectomy.

[Regulation mechanism of E2F1 transcription factor on M2 macrophages in full-thickness skin defect wounds of mice]

Objective: To explore the regulatory mechanism of E2F1 transcription factor on M2 macrophages in full-thickness skin defect wounds of mice. Methods: E2F1 gene knockout heterozygotes C57BL/6 mice and wild-type C57BL/6 mice were introduced and self-reproduced. Two weeks after birth, E2F1 gene knockout homozygotes mice and wild-type mice were identified by polymerase chain reaction (PCR). Twelve identified 6-8 weeks old male E2F1 gene knockout homozygotes C57BL/6 mice and wild-type C57BL/6 mice were selected respectively according to the random number table and set as E2F1 gene knockout group and wild-type group. A full-thickness skin defect wound was made on the back of each mouse. On post injury day (PID) 2 and 7, 6 mice in each group were selected according to the random number table and sacrificed, and the wound tissue was excised. The expression of CD68 and CD206 double positive M2 macrophages was observed by immunofluorescence method, and the percentage of CD206 positive cells was calculated. The protein expression of CD206 was detected by Western blotting. The mRNA expression of arginase 1 was detected by real-time fluorescent quantitative reverse transcription PCR (RT-PCR). Wound tissue specimens of the two groups on PID 7 were obtained, and the protein and mRNA expressions of peroxisome proliferator-activated receptor gamma (PPAR-γ) were detected by Western blotting and real-time fluorescent quantitative RT-PCR respectively. The above-mentioned experiments were repeated four times. Three specimens of wound tissue of mice in wild-type group on PID 7 were obtained to detect the relationship between E2F1 and PPAR-γ by co-immunoprecipitation and Western blotting, and this experiment was repeated two times. Data were processed with unpaired t test. Results: The size of PCR products of E2F1 gene knockout homozygotes C57BL/6 mice and wild-type C57BL/6 mice were 227 and 172 bp respectively, which were the same as those of the designed DNA fragments. On PID 2 and 7, the number of CD68 and CD206 double positive M2 macrophages in the wound tissue of mice in E2F1 gene knockout group was more than that of wild-type group, and the percentages of CD206 positive cells in the wound tissue of mice in E2F1 gene knockout group were (0.234±0.032)% and (0.584±0.023)% respectively, which were significantly higher than (0.129±0.017)% and (0.282±0.071)% of wild-type group (t=3.29, 3.54, P<0.05). On PID 2 and 7, the protein expression of CD206 in the wound tissue of mice in E2F1 gene knockout group were 1.00±0.23 and 1.63±0.26 respectively, which were significantly higher than 0.43±0.06 and 0.97±0.08 of wild-type group (t=2.41, 2.45, P<0.05). On PID 2 and 7, the mRNA expressions of arginase 1 in the wound tissue of mice in E2F1 gene knockout group were 0.482±0.105 and 0.195±0.031 respectively, which were significantly higher than 0.163±0.026 and 0.108±0.017 of wild-type group (t=3.04, 2.86, P<0.05). On PID 7, the protein and mRNA expressions of PPAR-γ in the wound tissue of mice in E2F1 gene knockout group were 0.61±0.12 and 0.51±0.13 respectively, which were significantly higher than 0.20±0.04 and 0.20±0.04 of wild-type group (t=3.36, 2.86, P<0.05). On PID 7, detection of the wound tissue of mice in wild-type group showed that PPAR-γ had unidirectional effect on E2F1. Conclusions: E2F1 transcription factor affects the polarization of M2 macrophages by inhibiting the expression of PPAR-γ, thereby inhibiting the healing process of full-thickness skin defect wounds in mice.

Regulation of Amino Acid Transporters and Sensors in Response to a High protein Diet: A Randomized Controlled Trial in Elderly Men

BACKGROUND

The mammalian target of rapamycin complex 1 (mTORC1) is fundamental for many cellular processes, yet it is often dysregulated with aging. Increased amino acid (AA) availability is correlated with the expression of AA transporters (AAT) and mTORC1 activity. Although many AA sensors and mediators have been proposed to relay the AA signal to mTORC1, it has not yet been determined if chronic dietary intervention affects the expression of AAT, sensors and mediators and their relationships with mTORC1 activity.

OBJECTIVE AND DESIGN

This study investigated whether the consumption of a diet containing either the current recommended daily allowance (RDA) of protein intake (0.8 g/kg/d) or twice the RDA (2RDA) for ten weeks affected the expression of targets associated with AA transport, sensing and mTORC1 regulation in 26 older men (70-81 years).

METHOD

Muscle biopsies were collected before and after the intervention under fasting conditions. Diets were controlled by providing fully prepared meals and snacks. Western blot and quantitative polymerase chain reaction were used to measure protein and gene expression respectively.

RESULTS

Consumption of 2RDA reduced the protein expression of L-type amino acid transporter 1 (LAT1). However, plasma leucine concentration and basal mTORC1 activity were unaltered. The downregulation of LAT1 did not affect the expression of AA sensors and mediators, including leucyl tRNA synthetase (LRS), cytosolic arginine sensor for mTORC1 (CASTOR1), Sestrin2 and Rag proteins. Instead, total ribosomal protein S6 (RPS6) was upregulated with 2RDA.

CONCLUSION

Ten weeks of 2RDA diet did not affect the fasting mTORC1 signaling, but increased total RPS6 might suggest improved muscular translational capacity to maintain muscular mass.

Association of serum galectin-3 with risks of death and vascular events in acute ischaemic stroke patients: the role of hyperglycemia

BACKGROUND AND PURPOSE

Whether the association between galectin-3 and stroke outcome is modified by fasting plasma glucose (FPG) is unknown. The aim was to evaluate the prognostic effect of galectin-3 amongst ischaemic stroke patients stratified by FPG.

METHODS

In all, 3082 ischaemic stroke patients were included in this study and serum galectin-3 was tested at baseline. The primary outcome was a composite outcome of death and vascular events, and secondary outcomes were death, stroke recurrence and vascular events within 1 year after stroke.

RESULTS

Increased galectin-3 was significantly associated with the primary outcome, stroke recurrence and vascular events in the patients with hyperglycemia but not in those with normoglycemia (P for interaction < 0.05 for all). The multivariate-adjusted hazard ratios (95% confidence intervals) were 1.72 (1.05-2.84), 2.64 (1.14-6.12) and 2.68 (1.33-5.38) for the primary outcome, stroke recurrence and vascular events, respectively. A linear association between galectin-3 and the primary outcome was observed in hyperglycemic patients (P for linearity = 0.007).

CONCLUSION

Increased galectin-3 was associated with the primary outcome, stroke recurrence and vascular events within 1 year after stroke in the patients with hyperglycemia, suggesting that galectin-3 may be an important prognostic factor for ischaemic stroke patients with hyperglycemia.

[The construction of three-dimensional visualization platform and its application in diagnosis and treatment for hilar cholangiocarcinoma]

OBJECTIVE

To explore the construction and clinical efficacy of three-dimensional(3D) visualization platform about diagnosis and treatment of hilar cholangiocarcinoma.

METHODS

From January 2009 to December 2015, a total of 32 patients with hilarcholangiocarcinoma treated in Zhujiang Hospital of Southern Medical University were analyzed.There were 20 male and 12 female patients aged from 40 to 85 years. Bismuth-Corlette 3D visualization type: 2 cases with type Ⅰ, 5 cases with type Ⅱ, 10 cases with type Ⅲa, 11 cases with type Ⅲb, 4 cases with type Ⅳ.Among 32 cases, there were 5 cases who were established liver 3D printing models to guide intraoperative real-time navigation.The clinical effect of this platform was evaluated by the operation time, intraoperative blood loss, laboratory test and postoperative complications.The 3D visualization platform consists of the preoperative surgical planning with the aid of virtual 3D reconstruction technology and intraoperative real-time navigation with 3D printing models.

RESULTS

The liver 3D models for all patients were constructed successfully, they could clearly show intrahepatic pipeline, size and location of tumors, relationship between tumor and intrahepatic pipeline.The 3D printing models could accomplish real-time intraoperative navigation surgery with strong stereoscopic sense.According to Bismuth classification 3D visualization type, 2 patients with type Ⅰ received local excision of tumor and choledochojejunostomy; 5 patients with type Ⅱ received resection of segment Ⅰ, Ⅳb and partial Ⅴ combined with choledochojejunostomy; 10 patients with type Ⅲa received right semi-hepatectomy combined with resection of segment Ⅰ and choledochojejunostomy; 11 cases with type Ⅲb received left semi-hepatectomy combined with resection of segment Ⅰ and choledochojejunostomy; 4 cases with type Ⅳ received resection of segment Ⅳb and Ⅴ combined with choledochojejunostomy.The operation time was 270-660 minutes; the mean intraoperative blood loss was 588 ml; the mean postoperative hospital stay was 25 days.The bilirubin level three day after operation was 233 μmol/L.There was 1 case presented biliary fistula and cured by conservative treatment; there was no incision infection, no liver failure and no perioperative deaths occurred.

CONCLUSION

The 3D visualization is valuable for optimizing the operation scheme preoperatively and navigating surgery accurately intraoperatively in real-time which may improve the precision of the operation and achieve better the recovery.

Uncertainty in the response of terrestrial carbon sink to environmental drivers undermines carbon-climate feedback predictions

Terrestrial ecosystems play a vital role in regulating the accumulation of carbon (C) in the atmosphere. Understanding the factors controlling land C uptake is critical for reducing uncertainties in projections of future climate. The relative importance of changing climate, rising atmospheric CO2, and other factors, however, remains unclear despite decades of research. Here, we use an ensemble of land models to show that models disagree on the primary driver of cumulative C uptake for 85% of vegetated land area. Disagreement is largest in model sensitivity to rising atmospheric CO2 which shows almost twice the variability in cumulative land uptake since 1901 (1 s.d. of 212.8 PgC vs. 138.5 PgC, respectively). We find that variability in CO2 and temperature sensitivity is attributable, in part, to their compensatory effects on C uptake, whereby comparable estimates of C uptake can arise by invoking different sensitivities to key environmental conditions. Conversely, divergent estimates of C uptake can occur despite being based on the same environmental sensitivities. Together, these findings imply an important limitation to the predictability of C cycling and climate under unprecedented environmental conditions. We suggest that the carbon modeling community prioritize a probabilistic multi-model approach to generate more robust C cycle projections.

[Application of indocyanine green-fluorescent imaging technique in planning resection line and real-time surgical navigation in small hepatocellular carcinoma]

Objective: To explore the value of near-infrared technology guided by indolecyanine green(ICG) in planning resection line and real-time surgical navigation in small liver cancer. Methods: From March to September 2015, 11 patients with hepatic tumors received hepatectomy were treated in First Department of Hepatobiliary Surgery, Zhujiang Hospital, Southern Medical University.There were 5 male and 6 female patients with average age of (55±10)years (range 39-70 years). Among whom, there were 9 cases with hepatocellular carcinoma and 2 cases with colorectal cancer. A near-infrared light camera system was used to detect the liver surfaces before resection, and to plan resection line and surgical specimens. A student's t test was used to compare continuous parametric variables. Results: The ICG-fluorescent imaging and histological examination had been used in the 15 lesions of the 11 patients. Among the 15 lesions, 7 lesions were detected by visual inspections, palpation and ICG-fluorescent imaging, 6 lesions were identified only by ICG-fluorescent imaging, 2 lesions were detected only by ICG-fluorescent imaging after resection.Results of pathologic examination indicated that the total fluorescent type include 5 well differentiated hepatocellular carcinoma and 2 cirrhotic nodule; the partial fluorescent type include 3 moderately differentiated hepatocellular carcinomas and 1 well differentiated hepatocellular carcinomas; the rim fluorescent type included 2 liver metastatic carcinoma and 2 poorly differentiated hepatocellular carcinomas. The average diameter of the tumor size measured by CT was (1.7±0.2)cm, while the average diameter measured by ICG-fluorescent imaging was (1.7±0.3)cm(t=-0.188, P>0.05). Conclusion: Near-infrared technology guided by ICG has important value in planning resection line and real-time surgical navigation in small liver cancer.

Increased expression of LncRNA BANCR and its prognostic significance in human epithelial ovarian cancer

PURPOSE

Long non-coding RNAs (lncRNAs) have been proved to play important roles in the tumorigenesis and development of human epithelial ovarian cancer (EOC). The aim of the present study was to investigate the expression and clinical value of BRAF-activated non-coding RINA (BANCR) in EOC patients.

MATERIALS AND METHODS

BANCR expression was detected in 84 EOC and 36 normal ovarian epithelial tissue samples. Association between BANCR levels and clinicopathological factors and patient prognosis was also analyzed.

RESULTS

BANCR expression was increased in EOC compared with normal ovarian epithelial tissues. Moreover, high expression of BANCR was closely correlated with advanced FIGO stage, higher serum, CAI125 expression level, and lymph node metastasis. Multivariate regression analysis identified BANCR overexpression as an independent unfavorable prognostic factor in EOC patients.

CONCLUSIONS

These findings suggested that BANCR may act as a tumor promoter in EOC and would be a novel diagnostic and prognostic marker for this disease.

Radiofrequency-induced thermal inactivation of Toxoplasma gondii oocysts in water

Toxoplasma gondii, a ubiquitous parasitic protozoan, is emerging as an aquatic biological pollutant. Infections can result from drinking water contaminated with environmentally resistant oocysts. However, recommendations regarding water treatment for oocyst inactivation have not been established. In this study, the physical method of radiofrequency (RF) power was evaluated for its ability to inactivate T. gondii oocysts in water. Oocysts were exposed to various RF energy levels to induce 50, 55, 60, 70 and 80 degrees C temperatures maintained for 1 min. Post-treatment oocyst viability was determined by mouse bioassay with serology, immunohistochemistry and in vitro parasite isolation to confirm T. gondii infections in mice. None of the mice inoculated with oocysts treated with RF-induced temperatures of > or =60 degrees C in an initial experiment became infected; however, there was incomplete oocyst activation in subsequent experiments conducted under similar conditions. These results indicate that T. gondii oocysts may not always be inactivated when exposed to a minimum of 60 degrees C for 1 min. The impact of factors such as water heating time, cooling time and the volume of water treated must be considered when evaluating the efficacy of RF power for oocyst inactivation.

Real-time quantitative polymerase chain reaction (qPCR) analysis with fluorescence resonance energy transfer (FRET) probes reveals differential expression of the four ERBB4 juxtamembrane region variants between medulloblastoma and pilocytic astrocytoma

AIMS

We report a comparative study on the mRNA expression of ErbB receptor tyrosine kinases, and in particular ERBB4 transcript variants, in two common paediatric brain tumours: medulloblastoma (MB) and pilocytic astrocytoma (PA).

METHODS

While the conventional real-time quantitative polymerase chain reaction was used to measure the expression of ERRBs and ErbB4-processing protease genes, the LightCycler fluorescence resonance energy transfer probes were specifically designed to investigate all of the known ERBB4 juxtamembrane (JM) and cytoplasmic transcript variants.

RESULTS

The overall expression of ERBBs suggests that ErbB2/ErbB4 heterodimers and ErbB4 homodimers may be major functional units of the ErbBs in MB, while ErbB2/ErbB3 heterodimers may play a more prominent role in addition to ErbB4-containing dimers in PA. Different expression patterns of ERBB4 JM transcripts in MB, PA and normal brain were observed. The JM-d variant was only detected in MBs, while JM-c was present in MB and PA but was not identified in normal brain. The expression of cleavable ERBB4 transcript variants was elevated in PAs and MBs compared with normal brain, while mRNA levels of ErbB4-processing proteases were similar in both tumour types and normal brain. This suggests that proteolytic cleavage of ErbB4 may be more common in MB and PA, which leads to signalling events divergent from those in normal brain.

CONCLUSION

Taken together, these results suggest that ErbB4 processing and function may be altered in brain tumours, such as MB and PA, via differential expression of JM transcript variants.

Different actions of secretin and Gly-extended secretin predict secretin receptor subtypes

Only one secretin receptor has been cloned and its properties characterized in native and transfected cells. To test the hypothesis that stimulatory and inhibitory effects of secretin are mediated by different secretin receptor subtypes, pancreatic and gastric secretory responses to secretin and secretin-Gly were determined in rats. Pancreatic fluid secretion was increased equipotently by secretin and secretin-Gly, but secretin was markedly more potent for inhibition of basal and gastrin-induced acid secretion. In Chinese hamster ovary cells stably transfected with the rat secretin receptor, secretin and secretin-Gly equipotently displaced (125)I-labeled secretin (IC(50) values 5.3 +/- 0.5 and 6.4 +/- 0.6 nM, respectively). Secretin, but not secretin-Gly, caused release of somatostatin from rat gastric mucosal D cells. Thus the equipotent actions of secretin and secretin-Gly on pancreatic secretion appear to result from equal binding and activation of the pancreatic secretin receptor. Conversely, secretin more potently inhibited gastric acid secretion in vivo, and only secretin released somatostatin from D cells in vitro. These results support the existence of a secretin receptor subtype mediating inhibition of gastric acid secretion that is distinct from the previously characterized pancreatic secretin receptor.

Regulation of parietal cell calcium signaling in gastric glands

The ligands interacting with enterochromaffin-like (ECL) and parietal cells and the signaling interactions between these cells were investigated in rabbit gastric glands using confocal microscopy. Intracellular calcium concentration ([Ca(2+)](i)) changes were used to monitor cellular responses. Histamine and carbachol increased [Ca(2+)](i) in parietal cells. Gastrin (1 nM) increased [Ca(2+)](i) in ECL cells and adjacent parietal cells. Only the increase of [Ca(2+)](i) in parietal cells was inhibited by H(2) receptor antagonists (H(2)RA). Gastrin (10 nM) evoked an H(2)RA-insensitive [Ca(2+)](i) increase in parietal cells. Carbachol produced large H(2)RA- and somatostatin-insensitive signals in parietal cells. Pituitary adenylate cyclase-activating peptide (PACAP, 100 nM) elevated [Ca(2+)](i) in ECL cells and adjacent parietal cells. H(2)RAs abolished the PACAP-stimulated [Ca(2+)](i) increase in adjacent parietal cells. Somatostatin did not inhibit the increase of [Ca(2+)](i) in parietal cells stimulated with histamine, high gastrin concentrations, or carbachol but abolished ECL cell calcium responses to gastrin or PACAP. Hence, rabbit parietal cells express histaminergic, muscarinic, and CCK-B receptors coupled to calcium signaling but insensitive to somatostatin, whereas rabbit and rat ECL cells express PACAP and CCK-B calcium coupled receptors sensitive to somatostatin.

Local pH elevation mediated by the intrabacterial urease of Helicobacter pylori cocultured with gastric cells

Helicobacter pylori resists gastric acidity by modulating the proton-gated urea channel UreI, allowing for pH(out)-dependent regulation of urea access to intrabacterial urease. We employed pH- and Ca(2+)-sensitive fluorescent dyes and confocal microscopy to determine the location, rate, and magnitude of pH changes in an H. pylori-AGS cell coculture model, comparing wild-type bacteria with nonpolar ureI-deletion strains (ureI-ve). Addition of urea at pH 5.5 to the coculture resulted first in elevation of bacterial periplasmic pH, followed by an increase of medium pH and then pH in AGS cells. No change in periplasmic pH occurred in ureI-deletion mutants, which also induced a slower increase in the pH of the medium. Pretreatment of the mutant bacteria with the detergent C(12)E(8) before adding urea resulted in rapid elevation of bacterial cytoplasmic pH and medium pH. UreI-dependent NH(3) generation by intrabacterial urease buffers the bacterial periplasm, enabling acid resistance at the low urea concentrations found in gastric juice. Perfusion of AGS cells with urea-containing medium from coculture at pH 5.5 did not elevate pH(in) or [Ca(2+)](in), unless the conditioned medium was first neutralized to elevate the NH(3)/NH(4)(+) ratio. Therefore, cellular effects of intrabacterial ammonia generation under acidic conditions are indirect and not through a type IV secretory complex. The pH(in) and [Ca(2+)](in) elevation that causes the NH(3)/NH(4)(+) ratio to increase after neutralization of infected gastric juice may contribute to the gastritis seen with H. pylori infection.

[The recognition of the epidemic area of tsutsugamushi disease on Nan Peng Lie Island in China and the strategy of prevention]

OBJECTIVE

To investigate the region for the epidemic area of tsutsugamushi disease.

METHODS

Epidemiological studies, Orientia tsutsugamushi isolation, and preventive measures were used.

RESULTS

The region belonged to epidemic area of south subtropical zone. The main host was found Rattus norvegicu. The main biological vector was Leptotrombidium deliens. The seasonal trends of the quantity of Rattus norvegicu and Leptotrombidium deliens were consistent with the incidence change of the disease in the region. Orientia tsutsugamushi has been isolated from Rattus norvegicu and Leptotrombidium deliens. Data showed that Orientia tsutsugamushi isolated strains mainly belongs to Karp. Sero-epidemiological data showed that antibodies of Orientia tsutsugamushi are 100.0% positive in the residents of the region and 4.0% in army men. After taking comprehensive preventive measures, the incidence was descending.

CONCLUSION

Nan Peng Lie island was proved an epidemic area of tsutsugamushi disease.

Role of neuropeptide-sensitive L-type Ca(2+) channels in histamine release in gastric enterochromaffin-like cells

Peptides release histamine from enterochromaffin-like (ECL) cells because of elevation of intracellular Ca(2+) concentration ([Ca(2+)](i)) by either receptor-operated or voltage-dependent Ca(2+) channels (VDCC). To determine whether VDCCs contribute to histamine release stimulated by gastrin or pituitary adenylate cyclase-activating polypeptide (PACAP), the presence of VDCCs and their possible modulation by peptides was investigated in a 48-h cultured rat gastric cell population containing 85% ECL cells. Video imaging of fura 2-loaded cells was used to measure [Ca(2+)](i), and histamine was assayed by RIA. Cells were depolarized by increasing extracellular K(+) concentrations or by 20 mM tetraethylammonium (TEA(+)). Cell depolarization increased transient and steady-state [Ca(2+)](i) and resulted in histamine release, dependent on extracellular Ca(2+). These K(+)- or TEA(+)-dependent effects on histamine release from ECL cells were coupled to activation of parietal cells in intact rabbit gastric glands, and L-type channel blockade by 2 microM nifedipine inhibited 50% of [Ca(2+)](i) elevation and histamine release. N-type channel blockade by 1 microM omega-conotoxin GVIA inhibited 25% of [Ca(2+)](i) elevation and 14% of histamine release. Inhibition was additive. The effects of 20 mM TEA(+) were fully inhibited by 2 microM nifedipine. Both classes of Ca(2+) channels were found in ECL cells, but not in parietal cells, by RT-PCR. Nifedipine reduced PACAP-induced (but not gastrin-stimulated) Ca(2+) entry and histamine release by 40%. Somatostatin, peptide YY (PYY), and galanin dose dependently inhibited L-type Ca(2+) channels via a pertussis toxin-sensitive pathway. L-type VDCCs play a role in PACAP but not gastrin stimulation of histamine release from ECL cells, and the channel opening is inhibited by somatostatin, PYY, and galanin by interaction with a G(i) or G(o) protein.

[Detection of C gene mutation strain in vertical transmission of hepatitis B virus and its significance]

OBJECTIVE

This study aims at detecting C gene mutation strain in vertical transmission of hepatitis B virus (HBV).

METHODS

HBV C gene nt 2,022 - 2,321 was directly sequenced.

RESULTS

Homology of HBV nucleotide sequence and amino acid sequence in mothers, fathers and their fetus was 100%. Mutation of 2,189 and 2,288 nucleotide of C gene resulted in substitution at the 97th and 130th amino acids.

CONCLUSION

C gene mutation strain is present in vertical transmission of HBV. Presence of mutation strain may be the cause of failure in vaccination.

Enhancement of Interdecadal Climate Variability in the Sahel by Vegetation Interaction

The role of naturally varying vegetation in influencing the climate variability in the West African Sahel is explored in a coupled atmosphere-land-vegetation model. The Sahel rainfall variability is influenced by sea-surface temperature variations in the oceans. Land-surface feedback is found to increase this variability both on interannual and interdecadal time scales. Interactive vegetation enhances the interdecadal variation substantially but can reduce year-to-year variability because of a phase lag introduced by the relatively slow vegetation adjustment time. Variations in vegetation accompany the changes in rainfall, in particular the multidecadal drying trend from the 1950s to the 1980s.

PACAP type I receptor activation regulates ECL cells and gastric acid secretion

Pituitary adenylate cyclase activating polypeptide (PACAP) is present in gastric nerves, and PACAP receptors (PAC1) are found on gastric enterochromaffin-like (ECL) cells. Expression of PAC1 splice variants in purified ECL cells was determined by RT-PCR. PACAP effects on ECL cells were analyzed by video imaging of [Ca(2+)](i) and histamine release; its effects on gastric glands were examined by confocal microscopy of [Ca(2+)](i) in ECL and parietal cells. PACAP action on D cells was measured by [Ca(2+)](i) and radioimmunoassay. PACAP effects on acid secretion were determined in fistula rats with or without neutralizing anti-somatostatin antibodies. All splice variants of PAC1 were found, but vasoactive intestinal polypeptide (VIP) receptor (VPAC) products were absent. PACAP-27 and -38 dose-dependently raise [Ca(2+)](i) in ECL cells, and stimulated histamine release. VIP had a much lower affinity, which demonstrates the presence of PAC1 but not VPAC. PACAP elevated [Ca(2+)](i) in ECL and parietal cells of superfused gastric glands, but only the parietal cell signal was inhibited by ranitidine, showing the absence of PAC1 on parietal cells, and demonstrating functional coupling between the cell types. PACAP and VIP stimulated calcium signaling and somatostatin release from D cells with almost equal efficacy. Acid secretion was stimulated after intravenous injection of PACAP into rats treated with somatostatin antibody. PACAP is a candidate as a mediator of neural regulation of acid secretion.

[Experimental studies on antioxidative effect of tongcao and xiao-tongcao polysaccharides]

OBJECTIVE

To observe the antioxidative effect of four kinds of Tongcao and Xiao-Tongcao polysaccharides.

METHOD

Aged mice (nine months) were abdominal administrated with four kinds of polysaccharides (Tongtuomu, Ximashanjingjiehua, Xinanxiuqiu, Ditanghua) at dosages of 160 mg/kg and 80 mg/kg for 45 days.

RESULT

Four kinds of polysaccharides could obviously decrease the content of serum and liver lipoperoxide(LPO) as well as the content of lipofuscin(LF) in brain and cardiac muscle of aged mice, and also increase the activity of superoxide dismutase(SOD) of red cells in aged mice.

CONCLUSION

The polysaccharide components of Tongtuomu and three kinds of Xiao-Tongcao have antioxidative effect, suggesting that these substances have antiageing function.

The pituitary adenylate cyclase activating polypeptide type 1 receptor (PAC1-R) is expressed on gastric ECL cells: evidence by immunocytochemistry and RT-PCR

The current study was undertaken to determine the presence and distribution of PAC1-Rs within the gastric mucosa. Polyclonal antibodies to the carboxyl terminus of the rat PAC1-R were generated and shown to be specific against the PAC1-R expressed in NIH 3T3 cells. Western blot analysis using isolated (approximately 85% pure) ECL cell membranes identified a 48 kD protein consistent with the calculated molecular mass of the cloned PAC1-R. RT/PCR performed using specific primers for the PAC1-R confirmed the presence of splice variants of the rat PAC1-R, but not VPAC1-R or VPAC2-R. These data provide the first direct evidence for the existence of functional PACAP Type I receptors on ECL cells of the gastric mucosa and suggest a potential role for PACAP in the stimulation of gastric acid secretion and in the regulation of the growth of ECL cells.

[Preliminary studies on pharmacological actions of tongca and xiao-tongcao polysaccharides]

OBJECTIVE

To study and compare the immunologic function and antioxidative effect of Tongcao(Tongtuomu) and Xiao-Tongcao(Ximashanjingjiehua, Xinanxiuqiu, Ditanghua) polysaccharides.

METHOD

Mice were abdominally administrated with four kinds of polysaccharides at dosages of 80 mg/kg and 40 mg/kg for 7-10 days.

RESULT

Four kinds of polysaccharides could increase the serum-lysozyme activity, phagocytic function of MPS and the serum hemolysin-antibody level in mice, inhibit the delayed hypersensitivity induced by DNCB in mice and raise the serum-catalase activity in mice.

CONCLUSION

Four kinds of Tongcao or Xiao-Tongcao polysaccharides have immunoregulative function and antioxidative effect. The results could enrich the contents of "A Study on Species-Sorting and Quality of Tongcao-Xiao-Tongcao Crude Drugs".

[Experimental studies on anti-inflammatory, antipyretic and diuretic effects of several species of tongcao and xiao-tongcao]

OBJECTIVE

To observe and compare the anti-inflammatory, antipyretic and diuretic effects of three kinds of Tongcao(Tongtuomu, Panyezhangyeshu and Luosan) and seven kinds of Xiao-tongcao(Ximashanjinjiehua, Xinanxiuqiu1. 2., Ditanghua, Suixuezhangcai, Qingjiaye and Zhongguo jinjiehua).

METHOD

Decoctions prepared from the above kinds of Tongcao and Xiao-tongcao crude drugs were given to rats at dosages of 8 g/kg and 4 g/kg by ig. Pharmacological actions were observed by means of carrageenan-induced swelling paws, fever models induced by beer-yeast or carrageenan and metabolic cage method in rats.

RESULT

All the experimental decoctions could inhibit carrageenan-induced swelling of rat paws in different degrees and exerted anti-pyretic effect on rat fever models induced by beer-yeast or carrageenan. Three kinds of Xiaotongcao(Ximashanjingjiehua, Xinanxiuqui2., Zhongguojinjiehua) had obvious diuretic effect on rats.

CONCLUSION

Decoctions of different species of Tongcao and Xiao-tongcao all have anti-inflammatory, antipyretic and diuretic effects, thus providing some pharmacologic basis for the efficacy assay, clinical application, species collation and quality study of Tongcao and Xiao-tongcao.

Galanin inhibition of enterochromaffin-like cell function

BACKGROUND & AIMS

Galanin, a 29-amino acid neuropeptide found in the gastric mucosa, inhibits basal and pentagastrin-stimulated acid secretion. Its cellular target is unknown. The aim of this study was to determine whether galanin inhibits Ca2+ signaling and histamine release in enterochromaffin-like (ECL) cells.

METHODS

Isolated rat ECL cells were purified to 85% homogeneity by a combination of elutriation, density gradient centrifugation, and 48-hour culture. Intracellular calcium concentration ([Ca2+]i) was determined using video imaging with Fura-2 in a 37 degreesC superfusion chamber. Histamine was measured by radioimmunoassay.

RESULTS

Reverse-transciption polymerase chain reaction of the ECL cell RNA showed a galanin type I receptor subtype. Galanin inhibited gastrin, Bay K8644, and K+ depolarization-induced calcium mobilization and entry as well as reduced basal calcium levels. Pretreatment with pertussis toxin decreased the effect of galanin. Galanin inhibited basal and gastrin-stimulated histamine release by approximately 60% with a median effective concentration of 1.10(-10) mol/L. The inhibitory actions of galanin on histamine release and Ca2+ influx could be reduced by a galanin antagonist, galantide.

CONCLUSIONS

Galanin's inhibition of acid secretion can be explained in part by inhibition of calcium signaling and histamine release from the ECL cells due to activation of a Gi,o protein-coupled receptor.

Properties of isolated gastric enterochromaffin-like cells

The gastric enterochromaffin-like cell (ECL) has been studied in gastric fundic glands by confocal microscopy and as a purified cell preparation by video imaging of calcium signaling and measurements of histamine release. Regulation of gastric acid secretion is largely due to alterations of histamine activation of the H2 receptor on the parietal cell and can be divided into central neural regulation, with direct actions of neuronally released mediators and into peripheral regulation by substances released from other endocrine cells. Gastric neuronal stimulation of acid secretion by alteration of ECL cell function is probably mediated by pituitary adenylate cyclase activating peptide (PACAP) receptors on the ECL cell, which activate calcium signaling and histamine release. Peripheral stimulation of acid secretion via the ECL cell is largely mediated by gastrin stimulation of calcium signaling and histamine release. Gastric neuronal inhibition of ECL cell function is probably mediated by galanin inhibition of calcium signaling, and histamine release and peripheral inhibition of ECL cell function is mainly due to somatostatin release from D cells.

Two functional forms of vascular endothelial growth factor receptor-2/Flk-1 mRNA are expressed in normal rat retina

Vascular endothelial growth factor (VEGF) is an important mediator of ocular neovascularization by exerting its endothelial specific mitogenic effects through high affinity tyrosine kinase receptors. By screening a rat retina cDNA library, we have isolated a clone encoding the full-length prototypic form of the rat VEGF receptor-2/Flk-1, as well as a short form of the mRNA that encodes the complete seven N-terminal immunoglobulin-like extracellular ligand-binding domains, transmembrane region, NH2-terminal half of the intracellular kinase domain, and kinase insert domain but does not encode the COOH-terminal half of the intracellular kinase domain and carboxyl-terminal region. Both forms of mRNA are detected in rat retina, although the short form is expressed at a lower level. VEGF induced a biphasic increase of cytoplasmic calcium with both forms in HK 293 transfected cells, indicating that both forms of the VEGF receptor-2/Flk-1 are functional and that the COOH-terminal half of the intracellular kinase domain and carboxyl region of VEGF receptor-2/Flk-1 are not strictly necessary for either ligand binding or this biological activity.

First intracellular loop of the human cholecystokinin-A receptor is essential for cyclic AMP signaling in transfected HEK-293 cells

Cholecystokinin (CCK)-A and CCK-B receptors are highly homologous members of the seven transmembrane domain G-protein-coupled receptor superfamily. Genes of both receptors contain five exons and share a similar exon-intron organization. To determine the structural basis of CCK-A receptor (CCK-AR) functionally coupled to Gs, a series of chimeric mutants were constructed by replacing exons of human CCK-B receptor (CCK-BR), from the second to the fifth (last) exon, with human CCK-AR counterparts. Binding and signal transduction properties of wild-type and chimeric receptors were examined in stably transfected HEK-293 cells. Chimeric receptors that maintained high affinity binding to CCK exhibited dose-dependent increases in intracellular calcium mobilization similar to both wild-type receptors. However, only the wild-type CCK-AR and chimeric mutants containing the second exon of CCK-AR were able to mediate significantly greater increases in intracellular cAMP content and adenylyl cyclase activity compared with wild-type CCK-BR. A CCK-BR mutant was further constructed by replacing five amino acids, Gly-Leu-Ser-Arg-(Arg)-Leu, in the first intracellular loop with the corresponding five CCK-AR specific amino acids, Ile-Arg-Asn-Lys-(Arg)-Met. The resultant receptor maintained high affinity binding to both CCK and gastrin and dose-dependent calcium responses similar to wild-type CCK-BR. However, this first intracellular loop mutant also gained positive cAMP responses to both sulfated CCK-8 and gastrin-17 with EC50 values of 8.5 +/- 1 nM and 23 +/- 7 nM, respectively. These data suggest that the first intracellular loop of CCK-AR is essential for coupling to Gs and activation of adenylyl cyclase signal transduction cascade.

[Antioxidative effect of constituents of herba Epimedii (ESPS)]

Herba Epimedii is a traditional Yang invigorating Chinese herb widely used in clinic. The experimental results have shown that ESPS obviously increases superoxide dismutase(SOD) activity of red cells and liver in aged mice and rats, and increases glutathione peroxidase(GSH-Px) activity of red cells in aged mice. On the other hand, ESPS obviously helps to reduce the content of serum and liver lipoperoxide(LPO) in aged mice and rats, as well as the content of lipofuscin(LF) in cardiac muscle of aged mice. The results suggest that being helpful in increasing SOD and GSH-Px activities and inhibiting the formation of LPO and LF, ESPS may be a good antiageing agent.

Physiology of isolated gastric endocrine cells

The regulation of gastric acid secretion is achieved in the periphery by interplay between three major gastric endocrine cells: the enterochromaffin-like (ECL) cell, the gastrin or G cell, and the somatostatin or D cell. Regulation of these cells is via stimulatory or inhibitory paracrine, endocrine, and neural pathways. Upregulation of ECL function is determined by activation of CCK-B receptors, by gastrin, and by activation of beta-adrenergic receptors, as well as by acetylcholine in some (10-29%) of the cells. Gastrin and acetylcholine produce typical biphasic calcium signals. Inhibition of ECL cell histamine release and calcium signaling is produced by somatostatin acting at a type 2 receptor, histamine acting at a histamine-3 receptor, and by peptide PYY. Stimulation of ECL cells results in activation of chloride channels, and there is evidence that voltage-dependent calcium channels, along with the receptor-operated calcium channels, also are responsible for elevation of [Ca]i. Depolarization-activated K+ channels presumably restore the potential after depolarization by activation of the chloride channel. The D cell is activated by either gastrin or CCK and appears to be inhibited by acetylcholine and somatostatin. The G cell is activated by acetylcholine and gastrin-releasing peptide (GRP) and is inhibited by somatostatin. The functional integration of these three cell types is the primary determinant of the degree of stimulation of the parietal cell.

Peptide YY inhibition of rat gastric enterochromaffin-like cell function

BACKGROUND & AIMS

The cellular target for peptide YY (PYY) inhibition of gastric acid secretion is unknown. The aim of this study was to determine whether PYY inhibits histamine release from isolated enterochromaffin-like (ECL) cells by stimulation of a selective Y receptor.

METHODS

Isolated rat gastric ECL cells were analyzed in short-term culture for histamine release and for changes in intracellular calcium concentration using video imaging.

RESULTS

Gastrin-stimulated histamine release was inhibited with a 50% inhibiting concentration of 2.10(-9) mol/L. Inhibition of histamine release and of calcium entry by PYY and [Pro34]PYY and no effect of PYY(3-36) characterizes an inhibitory Y1 receptor subtype. Reverse-transcription polymerase chain reaction of ECL cell RNA showed that the receptor was the nontruncated Y1 isoform. The inhibitory action of PYY and related peptides on gastrin-stimulated histamine release and calcium signaling was eliminated by pretreatment with 200 ng/mL pertussis toxin. Additive but not synergistic inhibitory effects of PYY and somatostatin on gastrin-stimulated histamine release were observed.

CONCLUSIONS

Activation of a Y1 inhibitory receptor subtype present on the gastric ECL cell that inhibits gastrin-induced ECL cell histamine release and Ca2+ entry by activation of a Gi or G(o) class of protein may account for inhibition of gastric acid secretion by PYY released from the small intestine.

[Effect of active constituents of Herba Epimedii on hypothalamic monoamine neurotransmitters and other brain functions in aging rats]

The active constituents of Herba Epimedii can raise the hypothalamic monoamine neurotransmitters levels in aging male rats and improve the learning and memory in aging rats and mice. It can also inhibit the activities of AchE both in brain tissues and whole blood in mice.

The study of DNA oxidative damage in benzene-exposed workers

Peripheral blood lymphocyte 8-hydroxy-2-deoxyguanosine (8-OHdG), were detected in 87 benzene-exposed and 30 control subjects by high performance liquid chromatograph coupled with an electrochemical detector system (HPLC-EC). The air concentration of benzene and its homologes in the workplace, urinary trans,trans-muconic acid (TTMA) as an internal dose of benzene exposure, were examined. The lymphocyte micronuclei (MN) as genotoxic and white blood cell (WBC) count as well as the myelotoxic markers of benzene were examined. Exposure to low, medium and high concentrations of benzene resulted in increased levels of 8-OHdG, which were 4.67, 26.12 and 29.89/10(5) dG, respectively, However, the 8-OHdG level observed in the control group was 3.738/10(5) dG). A good correlation between 8-OHdG formation and the groups exposed to external and internal benzene was observed (r = 0.77, 0.64, respectively). There was also a correlation between 8-OHdG and MN formation (r = 0.50). WBC levels were within normal range in all benzene-exposed subjects. It may be concluded that: benzene induced DNA oxidative damage in occupational exposure workers. The major factors influencing blood the 8-OHdG level were sex and toluene.

Selective ligand-induced intracellular calcium changes in a population of rat isolated gastric endocrine cells

BACKGROUND & AIMS

Peripheral regulation of acid secretion depends mainly on stimulation or inhibition of the three major gastric endocrine cells (enterochromaffin-like, gastrin, and somatostatin). The aim of this paper was to define physiological responses of enterochromaffin-like, gastrin, and somatostatin cells in a mixed endocrine cell population by measuring ligand-selective changes of intracellular calcium ([Ca2+]i) in individual cells.

METHODS

Endocrine cells were enriched from a rat gastric cell suspension by elutriation, a density-gradient fractionation, and a 48-hour short-term culture. [Ca2+]i responses of individual cells to various ligands such as gastrin/carboxy-terminal cholecystokinin octapeptide and selective cholecystokinin antagonists, carbachol, and gastrin-releasing peptide were monitored using video imaging in a perfusion chamber. Characteristic [Ca2+]i changes distinguished the three cell types, confirmed by immunostaining.

RESULTS

All enterochromaffin-like cells respond to cholecystokinin-B receptor stimulation, but only a few respond to carbachol. Gastrin cells respond to both gastrin-releasing peptide and carbachol but not to cholecystokinin-receptor agonists. Somatostatin cells have both stimulatory cholecystokinin-A and cholecystokinin-B receptors and inhibitory muscarinic receptors. All cells have inhibitory somatostatin receptors.

CONCLUSIONS

Calcium-signaling responses of gastric endocrine cells are distinctive. This allows individual cell types in a mixed population to be characterized and permits an analysis of the hormones and transmitters that act directly on a specific cell type.

[Determination of plasma level of platelet activating factor in cirrhotic patients and its relation to endotoxemia]

The plasma levels of platelet activating factor (PAF) were measured in 27 decompensated cirrhotic patients and 11 controls, using platelet aggregation bioassay. At the same time, the levels of endotoxin were also measured. The results showed that the levels of plasma PAF in decompensated cirrhotic patients were higher than those in the controls (5.34 +/- 1.94 ng/ml:1.18 +/- 0.24 ng/ml, P less than 0.01), and were higher in the cirrhotic patients with endotoxemia than in those without endotoxemia (6.19 +/- 2.21 ng/ml:3.89 +/- 0.92 ng/ml, P less than 0.01). The level of plasma PAF is related significantly to the level of endotoxin (r = 0.67, P less than 0.01)). We conclude that plasma PAF is increased in cirrhotic patients, especially in those with endotoxemia, and PAF could be involved in the pathophysiological changes in endotoxemia and other complications of cirrhosis.