[Different methods in predicting mortality of pediatric intensive care units sepsis in Southwest China]

Objective: To investigate the value of systemic inflammatory response syndrome (SIRS), pediatric sequential organ failure assessment (pSOFA) and pediatric critical illness score (PCIS) in predicting mortality of pediatric sepsis in pediatric intensive care units (PICU) from Southwest China. Methods: This was a prospective multicenter observational study. A total of 447 children with sepsis admitted to 12 PICU in Southwest China from April 2022 to March 2023 were enrolled. Based on the prognosis, the patients were divided into survival group and non-survival group. The physiological parameters of SIRS, pSOFA and PCIS were recorded and scored within 24 h after PICU admission. The general clinical data and some laboratory results were recorded. The area under the curve (AUC) of the receiver operating characteristic curve was used to compare the predictive value of SIRS, pSOFA and PCIS in mortality of pediatric sepsis. Results: Amongst 447 children with sepsis, 260 patients were male and 187 patients were female, aged 2.5 (0.8, 7.0) years, 405 patients were in the survival group and 42 patients were in the non-survival group. 418 patients (93.5%) met the criteria of SIRS, and 440 patients (98.4%) met the criteria of pSOFA≥2. There was no significant difference in the number of items meeting the SIRS criteria between the survival group and the non-survival group (3(2, 4) vs. 3(3, 4) points, Z=1.30, P=0.192). The pSOFA score of the non-survival group was significantly higher than that of the survival group (9(6, 12) vs. 4(3, 7) points, Z=6.56, P<0.001), and the PCIS score was significantly lower than that of the survival group (72(68, 81) vs. 82(76, 88) points, Z=5.90, P<0.001). The predictive value of pSOFA (AUC=0.82) and PCIS (AUC=0.78) for sepsis mortality was significantly higher than that of SIRS (AUC=0.56) (Z=6.59, 4.23, both P<0.001). There was no significant difference between pSOFA and PCIS (Z=1.35, P=0.176). Platelet count, procalcitonin, lactic acid, albumin, creatinine, total bilirubin, activated partial thromboplastin time, prothrombin time and international normalized ratio were all able to predict mortality of sepsis to a certain degree (AUC=0.64, 0.68, 0.80, 0.64, 0.68, 0.60, 0.77, 0.75, 0.76, all P<0.05). Conclusion: Compared with SIRS, both pSOFA and PCIS had better predictive value in the mortality of pediatric sepsis in PICU.

[Association between physical exercise and non-alcoholic fatty liver disease in people infected with hepatitis B virus]

Objective: To investigate the association between physical exercise and non-alcoholic fatty liver disease (NAFLD) in people infected with HBV. Methods: The information about the 3 813 participants infected with HBV, including the prevalence of NAFLD, prevalence of physical exercise and other covariates, were collected from the National Science and Technology Major Project of China during 2016-2020. The logistic regression model was used to evaluate the association between physical exercise and NAFLD in HBV infected patients, and subgroup analysis was performed to identify the effect modifiers. Results: A total of 2 259 HBV infected participants were included in the final analysis and 454 (20.10%) had NAFLD. After adjusting for covariates, we found that moderate physical exercise was a protective factor for NAFLD (OR=0.66, 95%CI: 0.46-0.94). Subgroup analysis suggested that the protective effect of moderate physical exercise on NAFLD might be stronger in women (OR=0.61, 95%CI: 0.36-1.01), those <45 years old (OR=0.24, 95%CI: 0.06-0.80), those who had low education level (OR=0.16, 95%CI: 0.04-0.49), those who had low annual income (OR=0.39, 95%CI: 0.16-0.89 for <30 000 yuan RMB; OR=0.64, 95%CI: 0.40-1.00 for 30 000-80 000 yuan RMB), those who had hypertension (OR=0.45, 95%CI: 0.21-0.88), those with BMI ≥24.0 kg/m² (OR=0.66, 95%CI: 0.43-1.01), those who had more daily fruit or vegetable intake (OR=0.61, 95%CI: 0.38-0.97), those who had more daily meat intake (OR=0.49, 95%CI: 0.23-0.97), and those who had no smoking history (OR=0.66, 95%CI: 0.45-0.95) or passive smoking exposure (OR=0.61, 95%CI: 0.37-0.97). Conclusions: Among HBV infected patients, moderate physical exercise was negatively associated with the prevalence of NAFLD. Women, young people, those who had low education level, those who had low annual income, those with hypertension, those with high BMI, those who had more daily fruit or vegetable and meat intakes, and those who had no smoking history or passive smoking exposure might be more sensitive to the protective effect.

Chemical profiling of Fritillariae thunbergii Miq prepared by different processing methods reveals two new quality markers: Zhebeininoside and imperialine-3-β-D-glucoside

ETHNOPHARMACOLOGICAL RELEVANCE

Fritillariae thunbergii Miq (FTM)exhibit versatile biological activities including the significant antitussive and expectorant activities. As a herbal medicine, the therapeutic effects of FTM may be expressed by multi-components which have complicated integration effects on multi-targets. With the time going, the different processing methods of FTM has been changed a lot. Thus，the study described the effect of processing methods to FTM and its quality.

MATERIAL AND METHOD

Studies were undertaken by using UHPLC-LTQ Orbitrap MS and pharmacodynamic models. All reagents were involved of analytical grade. While a HPLC-ELSD's method has been developed and validated, a certified Quality System is conformed to ICH requirements. The experimental animals followed the animal welfare guidelines.

AIM OF THE STUDY

We aimed to found the differences after the different processing methods of FTM, and to demonstrate the changes could be selected as quality control indicators, and established a method for simultaneous determination of these for quality control.

RESULTS

we have previously found two new steroidal alkaloids: zhebeininoside and imperialine-3-β-D-glucoside from the different processing methods of FTM, which is the difference between the different processing methods of FTM, mainly on the steroidal alkaloids. The activity analysis of zhebeininoside, imperialine-3-β-D-glucoside, verticine and verticinone showed that the mouse model of cough expectorant has antitussive effect. The positive drug selected was dextromethorphan syrup. The positive group showed biological activity, but the blank group showed nothing. The model group showed illness which means that the model was effective. There are two ways of the mechanism of action of the expectorant action which can make sputum thin, reduce its viscosity, and be easy to cough up, or can accelerate the movement of mucous cilia in the respiratory tract and promote the discharge of sputum. In our study, the content of phenol red was significantly reduced in the administration group.

CONCLUSIONS

To sum up, our results suggest that zhebeininoside and other three components cloud be selected as quality control indicators, and a method for simultaneous determination of zhebeininoside and other three components was established for quality control.

[Treatment of PTA Wastewater by Modified Anode Microbial Fuel Cell]

The purpose of this study was to investigate the effect of different modified anodes on the microbial fuel cell(MFC) and the effect of MFC on the treatment of refractory wastewater. Based on a single room air cathode, the anode of MFC was modified by 0.10 g of tourmaline, 75% manganese bioxide/halloysite nanotube(MnO₂/HNT) and multi-walled carbon nanotube-carboxyl(MWCNT-COOH), respectively. The results showed that, the removal rate of purified terephthalic acid(PTA) was higher than 70%, and the chemical oxygen demand(COD) removal rate was more than 79% in MFC with different modified anodes. Compared with others, MFC with MWCNT-COOH modified anode obtained the maximum output voltage and maximum power density, which were 529 mV and 252.73 mW·m^-2, respectively.

Effects of vitamin D or its analogues on the mortality of patients with chronic kidney disease: an updated systematic review and meta-analysis

The objective of this study was to assess whether vitamin D (VD) treatment alters the overall all-cause and cardiovascular mortalities in a chronic kidney disease (CKD) population. We systematically searched PubMed, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials without language restriction, until the publication date of 22 February 2016. All related literatures that compared VD treatment with non-VD treatment and reported the mortality of patients with CKD (including those undergoing dialysis) were identified. Pooled risk ratios (RR) and 95% confidence intervals (CI) were calculated by using the random- and fixed-effects models. Randomised controlled trials (RCTs) that used the intention-to-treat principle and observational studies (OSs) were analysed separately. For this study, 38 studies involving 223 429 patients (17 RCTs, n=1819 and 21 OSs, n=221610) were included. In the OSs, VD treatment was significantly associated with reductions in both all-cause and cardiovascular mortalities; however, such significant association was not found in the RCTs. The existing RCTs do not provide sufficient or precise evidence that VD supplementation affects the mortality of patients with CKD, although subsets of patients that could potentially benefit from VD treatment can be identified by using the existing data from the RCTs. Nevertheless, large-size RCTs are needed in the future to assess any potential differences in survival prospectively.

Combined promoting effects of low-Pd-containing and Cu-doped LaCoO3 perovskite supported on cordierite for the catalytic combustion of benzene

The catalytic activities for benzene oxidation and resistance to SO2 poisoning were tested for a series of Pd/La-Cu-Co-O/cordierite catalysts, which were prepared using a multiple-step impregnation method. The XRD, SEM, and IR characterization techniques were performed to investigate the relationship between the catalytic performance and its physicochemical properties. When Pd/La-Cu-Co-O/cordierite catalysts with Pd loadings of 0.06 and 0.08 % were prepared at a calcination temperature of 500 °C for 5 h, they exhibited similar catalytic activity and sulfur resistance. When the concentration of benzene was 1500 ppm and the GHSV was 20000 h(-1), the benzene conversion was above 95 % at a reaction temperature of 350 °C in SO2 existing at 100 ppm. These results were mainly attributed to the cooperation between La-Cu-Co-O perovskite and the noble metal Pd. Specifically, the addition of copper can strengthen the catalytic activity of La-Co-O/cordierite catalysts by decreasing the crystalline size of the active ingredients. A moderate Pd addition can drastically improve the sulfur resistance and further improve the catalytic activity of the La-Cu-Co-O/cordierite catalyst.

Telmisartan inhibited angiotensin II-induced collagen metabolic imbalance without directly targeting TGF-β 1/Smad signaling pathway in cardiac fibroblasts

AIM

Cardiac fibrosis is an important pathological process of cardiac remodeling. A large number of studies have shown that telmisartan can attenuate cardiac fibrosis through acting on angiotensin II 1 receptor (AT1R), and TGF-β 1/Smad signaling molecule is an important pathway to achieve this effect. The aim of the study was to clarify whether, with excessive activation of RAAS system, telmisartan could also directly target TGF-β 1/Smad signaling pathway to have the function of anti-cardiac fibrosis.

METHODS

In this study, neonatal rat cardiac fibroblasts were cultured and AngII or TGF-β 1 was administered for treatment or pre-incubation, and then telmisartan was used for 24 hours' incubation. Western blot and enzyme-linked immunosorbent assay (ELISA) tests were performed to detect protein expressions.

RESULTS

The results showed that telmisartan could inhibit collagen synthesis and collagen metabolic imbalance under the effect of Ang II, but telmisartan could not have such function in TGF-β 1-induced cardiac fibroblasts. It was further confirmed by western blot method that telmisartan could inhibit TGF-β 1/Smad signaling molecule expression under the effect of Ang II, but telmisartan had no effect on TGF-β 1-induced Smad signaling molecule expression.

CONCLUSION

According to the present study telmisartan played a role of anticardiac fibrosis without directly targeting TGF-β 1/Smad signaling pathway molecule.

Epsilon-aminocaproic acid improves postrecirculation hemodynamics by reducing intraliver activated protein C consumption in orthotopic liver transplantation

BACKGROUND

Activated protein C (APC) is related to regulating the inflammatory response and hemodynamic stability upon reperfusion in cardiac operations and orthotopic liver transplantation (OLT). Epsilon-aminocaproic acid (EACA) is frequently used to treat fibrinolysis during OLT. It also has inhibitory effects related to the inflammatory response. However, it remains to be determined whether EACA can attenuate intraliver APC consumption and improve hemodynamic stability after reperfusion during OLT.

METHODS

Fifty-nine recipients were randomized to receive either EACA (150 mg kg(-1) given intravenously prior to incision, followed by 15 mg kg(-1) h(-1) infusion until 2 h after the graft reperfusion) or the same volume of saline. Blood samples to assess plasma APC and protein C were obtained immediately before and after reperfusion from the inferior caval effluent or the portal veins for calculation of transliver differences (Δ). Hemodynamics and vasoactive medication use during the reperfusion period were observed in both groups.

RESULTS

No transhepatic changes in protein C were found in either group. Immediately after reperfusion, a marked intraliver consumption of APC was noted in all recipients (P < 0.001), and intraliver consumption of APC in the control group was greater than that in the EACA-treated group (P < 0.05). Fewer requirements for vasoactive medication use after reperfusion and better initial graft function were noted in the EACA-treated group (P < 0.05).

CONCLUSIONS

EACA can attenuate intraliver APC consumption and improve hemodynamic stability after reperfusion and initial graft function during OLT.

Role of anhepatic time in endothelial-related coagulation in liver transplantation

BACKGROUND

Disturbances in coagulation homeostasis are common in patients undergoing orthotopic liver transplantation (OLT) and anhepatic period is one of the important factors related to the coagulation abnormalities. The endothelium can regulate hemostasisby producing substances such as thrombomodulin (TM). The primary aim was to evaluate the effect of an hepatic time on the thrombomodulin-protein C system in patients undergoing OLT.

METHODS

Fifty patients undergoing OLT were stratified in two groups: anhepatic time ≥ 60 min (N.=18) or anhepatic stage <60 min (N.=32). TM, protein C, activated protein C (APC) and (free) protein S plasma concentrations were measured by enzymelinked immunosorbent assays (ELISA) at the start of the surgery (To); immediately before the anhepatic period (A1); immediately before reperfusion (A2); 5 minutes; 15 minutes; 30 minutes after reperfusion of the graft (R1; R2; R3); at the end of operation (R4); the first day after operation (R5).

RESULTS

Blood loss and transfusion were significantly greater in patients whose anhepatic time ≥ 60 min during the operation. TM levels increased most in patients whose anhepatic time ≥ 60 min. Protein C levels remained low throughout the surgery and decreased significantly at other points compared with To (P<0.05). There were no differences in protein C levels between groups except R5. The ratio of circulating APC activity to protein C antigen (APC/PC) increased significantly during the surgery. APC/PC ratio in the neohepatic stage increased significantly in patients whose anhepatic time ≥ 60 min (P<0.05).

CONCLUSION

Patients with prolonged anhepatic time had greater changes in the thrombomodulin-protein C system.

High NH(4)(+)-N concentration wastewater treatment by shortcut nitrification-denitrification using a system of A/O inner loop fluidized bed biofilm reactors

In this experiment, a rapid mass-transfer inner loop fluidized bed biofilm reactor (ILFBBR) was employed to treat synthetic high ammonia nitrogen-containing (NH(4)(+)-N) wastewater by shortcut nitrification-denitrification. The reactor operation was stable after a short start-up period. Ammonia oxidizing bacteria (AOB) were predominant and 65% nitrite (NO(2)(-)-N/NO(x)(-)-N) levels were achieved. During the nitrification-denitrification period, the removal rates of NH(4)(+)-N and total nitrogen (TN) reached 94 and 82%, respectively. From the material balance, it was indicated that 87% of NH(4)(+)-N was removed by shortcut nitrification. The features of ILFBBR and the benefits of shortcut nitrification were combined in this experiment, and showed an excellent removal of NH(4)(+)-N from high-concentration NH(4)(+)-N wastewater.

A cascade of anoxic and oxic fluidized bed biofilm reactors for treatment of synthetic municipal wastewater

In this study, a cascade of anoxic and oxic fluidized bed biofilm reactors system was carried out to treat synthetic municipal wastewater. The parameters of the influent flow rates and C/N ratios were discussed. System performance was acceptable for chemical oxygen demand (COD), ammonia, and total nitrogen removal. A decrease of ammonia and total nitrogen removal efficiencies, however, was observed when the influent flow rates increased to 5.04 and 6.12 1 h(-1). Total nitrogen removal decreased at the influent C/N ratio of 3:1. The measured ratios of COD reduction in the anoxic column to nitrogen removal through nitrification-denitrification were 3.7, 3.5, 3.3, and 3.1 g COD/g(-1) N on average when the influent C/N ratios changed from 6:1 to 3:1. The observed sludge yield (Yobs) was 0.169 g VSS g COD(-1) because of perfect denitrification in the anoxic column and the relatively long solids retention time.

Sevoflurane protects against acute kidney injury in a small-size liver transplantation model

BACKGROUND

Living donor liver transplantation (LDLT) patients run the risk of developing acute kidney injury (AKI) and subsequent chronic kidney disease, affecting morbidity and mortality. Sevoflurane has anti-inflammation properties, and renal ischemia/reperfusion under sevoflurane anesthesia resulted in drastic improvements in renal function. Extrahepatic metabolism of sevoflurane has been reported in patients undergoing liver transplantation, and might lead to nephrotoxicity. However, whether sevoflurane anesthesia is safe with regard to renal function in small-size liver transplantation needs further investigation. As neutrophil gelatinase-associated lipocalin (NGAL) is an early predictive biomarker of AKI, we looked at the renal effects of sevoflurane in a rat liver transplantation model using small-for-size grafts to investigate the changes of NGAL level and kidney histology.

METHODS

Sixty male Sprague-Dawley rats were randomly divided into 2 groups after 50% size liver transplantation. Rats were anesthetized with chloral hydrate or with sevoflurane and subjected to liver transplantation. Twelve rats in each group were used for the survival study and 6 rats were used for the hemodynamic study. Six rats in each group were sacrificed 2 or 24 h after reperfusion. We harvested kidneys and serum for further analysis, including histological and functional parameters; TNF-α, IL-6 and NGAL immunoassay; expressions of myeloperoxidase (MPO) activity; and NF-κB in renal tissues.

RESULTS

Rats in the sevoflurane group had significantly lower Scr 24 h after reperfusion compared with those in the chloral hydrate group. Rats in the sevoflurane group demonstrated significantly reduced NGAL concentrations compared with rats in the chloral hydrate group 2 h after reperfusion. Epithelial necrosis in the chloral hydrate group (3.2 ± 0.8) was greater than that in the sevoflurane group (1.5 ± 1.1; p < 0.05). Sevoflurane anesthesia resulted in significantly lower plasma TNF-α and IL-6 concentrations and reduced MPO concentrations 2 h after reperfusion (p < 0.05). NF-κB protein levels 2 h after reperfusion increased by at least 110% in the chloral hydrate group relative to the sevoflurane group 2 h after reperfusion (p < 0.05). However, the urine inorganic fluoride concentrations increased significantly (p < 0.001) 2 h after reperfusion in the sevoflurane group (6.1 ± 1.5 μmol·l⁻¹) compared with the chloral hydrate group.

CONCLUSIONS

Sevoflurane anesthesia can attenuate renal injury and modulate inflammatory cascades in small-size liver transplantation using rat models.

[Electricity generation using high concentration terephthalic acid solution by microbial fuel cell]

The high concentration terephthalic acid (TA) solution as the substrate of microbial fuel cell (MFC) was studied to generate electricity. The open circuit voltage was 0.54 V after inoculating for 210 h with anaerobic activated sludge, which proved that TA can be the substrate of microbial fuel cell to generate electricity. The influence of pH and substrate concentration on generating electricity was studied deeply. The voltage output of external resistance (R = 1,000 Omega) was the highest when pH was 8.0. It increased as the substrate concentration increasing and tended towards a maximum value. The maximum voltage output Umax was 0.5 V and Ks was 785.2 mg/L by Monod equation regression. When the substrate concentration (according to COD) was 4000 mg/L, the maximum power density was 96.3 mW/m2, coulomb efficiency was 2.66% and COD removal rate was 80.3%.

[Influences of inorganic anions on oxidation of phenol by CuO-H2O2]

Phenol was selected as a model pollution substrate. The influences and mechanism of inorganic anions on its oxidation were investigated in neutral solution at low temperature and atmospheric pressure. Results showed that phenol could be removed efficiently by CuO and H2O2 with 94.7% removal rate in 10 min, which followed hydroxyl radical oxidation mechanism. Inorganic anions influenced the oxidation with different mechanisms. Higher concentration would lead to more significant influences. HCO3(-) accelerated the inefficient decomposing of H2O2. The decomposing rate constants increased from 0.3738 min(-1) at concentration of 0 mmol x L(-1) to 0.5347 min(-1) at concentration of 20 mmol x L(-1). The TOC removal rate constants decreased from 0.267 min(-1) to 0.0194 min(-1) correspondingly. HPO4(2-) retarded the H2O2 decomposing and inhibited the phenol oxidation. The decomposing rate constants of H2O2 and the removal rate constants of TOC decreased from 0.3738 min(-1), 0.267 min(-1) to 0.0338 min(-1), 0.0338 min(-1) respectively. Cl(-) was good at H2O2 decomposing and phenol removal with simultaneously increasing the H2O2 decomposing rate constants and the TOC removal rate constants from 0.3738 min(-1), 0.267 min(-1) to 0.6040 min(-1), 0.3879 min(-1) respectively. NO3(-) and SO4(2-) had few influences on H2O2 decomposing and phenol removal.

Sensitivity and specificity of bispectral index for classification of overt hepatic encephalopathy: a multicentre, observer blinded, validation study

BACKGROUND

The severity of hepatic encephalopathy is currently graded clinically using West Haven criteria and psychometric tests.

OBJECTIVE

To assess the discriminative power of the bispectral index (BIS) monitor to classify the degree and progression of hepatic encephalopathy.

DESIGN

A consecutive, multicentre, observer blinded validation study.

SETTING

Medical University of Graz (Graz, Austria), Zhejiang University First Affiliated Hospital (Hang Zhou, China), and Cairo University (Cairo, Egypt).

PATIENTS

28 consecutive patients with hepatic encephalopathy were first enrolled at Medical University of Graz as a test set. The estimated BIS cut off values were subsequently tested in a validation set of 31 patients at Zhejiang University First Affiliated Hospital and 26 patients at Cairo University; 18 patients were reassessed later in a longitudinal study. Fifteen of 85 patients (18%) were excluded from the final analysis (11 became too agitated with high electromyographic activity; four fell asleep during the recording).

RESULTS

Applying the Austrian BIS cut off values of 85, 70, and 55 for discriminating West Haven grades 1 to 4 yielded agreement between BIS classification and West Haven grades in 40 of the 46 validation patients (87%), and in 16 of the 18 follow up patients (89%). Mean (SD) BIS values differed significantly between patients with West Haven grade 1 (90.2 (2.5)), grade 2 (78.4 (6.6)), grade 3 (63.2 (4.8)), and grade 4 (45.4 (5.0)).

CONCLUSIONS

BIS is a useful measure for grading and monitoring the degree of involvement of the central nervous system in patients with chronic liver disease.

Family-based association study of Epsin 4 and Schizophrenia

Recently, Pimm et al. identified Epsin 4 on chromosome 5q33 as a susceptibility gene for schizophrenia in the British population, based on linkage and association evidence. In Pimm's case-control study, both the single polymorphisms and the individual haplotypes at the 5' end of the gene showed genetic association with schizophrenia. Here, we report the first study evaluating the relevance of Epsin 4 and schizophrenia outside the British population. Markers showing positive results in the original work as well as two additional polymorphisms were genotyped in 308 Han Chinese family trios. Transmission disequilibrium analysis was used to test for association of single-locus markers and multi-locus haplotypes with schizophrenia. Although no individual marker was significant at the P=0.05 level, the haplotypes detected in our samples, different from those previously reported, showed strong evidence of association (most significant global P=0.0021). Our results indicate the presence of a locus near the 5' end of Epsin 4 conferring susceptibility to the disease and provide further support for Epsin 4 as an important potential contributor to genetic risk in schizophrenia.

Plasma propofol concentrations during orthotopic liver transplantation

OBJECTIVE

The aim of this study was to investigate the changes in plasma concentrations of propofol in three phases (the paleohepatic, anhepatic, and neohepatic phases) during orthotopic liver transplantation (OLT) using target-controlled infusion (TCI).

METHODS

Ten patients undergoing OLT without venovenous bypass were studied (age 29-53 years, weight 56-79 kg). After intubation, a non-hypnotic target concentration of propofol 0.5 microg ml(-1) using a Diprifusor pump (Zeneca Pharmaceuticals, Macclesfield, UK) was administered as a supplement anesthesia throughout the procedure. Plasma samples were obtained in each phase for propofol assay, respectively. Performance parameters for the Diprifusor system in each phase, the percentage median performance error (MDPE), the percentage median absolute performance error (MDAPE), and the percentage median absolute constancy error (MDACE) were evaluated.

RESULTS

In all patients, measured plasma propofol concentrations were several times higher than Diprifusor values in each phase during the procedure. In nine patients, propofol concentrations in the anhepatic phase were higher than those in the paleohepatic or neohepatic phase (P < 0.05). There were no significant differences between the paleohepatic and neohepatic phases. Interindividual variation of the plasma propofol concentrations was significant (P < 0.05). Percentage median performance error of Diprifusor in each phase, as well as MDAPE, was large (>300%) and was significantly higher in the anhepatic phase (P < 0.01), whereas MDACE was relatively small and there was no significant difference between phases.

CONCLUSIONS

Models used by Diprifusor are not suitable for liver transplantation patients. A further study should be performed in order to determine all pharmacokinetic parameters of propofol in these patients.

A family-based and case-control association study of the NOTCH4 gene and schizophrenia

Recently a strong positive association between schizophrenia and Notch4 has been reported. Both individual markers and haplotypes showed association with the disease, with five markers (three microsatellites and two SNPs) being tested. In order to test this finding we genotyped these markers in the Han Chinese population using a sample of 544 cases and 621 controls as well as >300 trios. Analysis of allele, genotype and haplotype frequencies in both samples showed no association between the markers and the disease. Our results would indicate that a significant role for the Notch4 gene in schizophrenia can be ruled out in the Han Chinese. However, similar studies are necessary in the Caucasian population as linkage disequilibrium arrangements and founder effects may differ between these two populations.

Direct coronary artery perfusion from the left ventricle

OBJECTIVES

Trends in coronary bypass surgery require less invasive techniques and more conduits. We investigated the ability of direct coronary perfusion from the left ventricle to support regional and global cardiac function.

METHODS

A conduit was established between the left ventricle and left anterior descending coronary artery (n = 6) with an interposed Starling resistor that allowed for graded regulation of backward flow. Changes of coronary flow, regional function in the territory of the left anterior descending coronary artery, and reactive hyperemia were studied. In 3 separate dogs, functional tolerance to increased heart rate was tested. In another 3 dogs, left ventricle-left anterior descending and left ventricle-left circumflex coronary artery conduits were established simultaneously (double conduit), and global function was tested.

RESULTS

Without flow regulation, flow through the left ventricle-left anterior descending conduit exhibited high peaking (102 +/- 35 mL/min), midsystolic forward flow, and large pandiastolic backward flow (peaking at -47 +/- 22 mL/min). Mean coronary flow and regional function were maintained at 46.0% +/- 7.1% (35.8%-54.2%) and 45.3% +/- 29.1% (-1.8%-74.2%) of their respective normal values. When the Starling resistor was used to regulate backward flow, these values increased to 70.8% +/- 12.5% (56.8%-90.4%) and 70.2% +/- 27.8% (23.6%-107.7%), respectively. Coronary and functional reserve with a left ventricle-left anterior descending conduit were not observed. With the double conduit, global ventricular contractility indexed by end-systolic pressure-volume relation averaged 46% +/- 35% of its normal value.

CONCLUSIONS

A left ventricle-coronary artery conduit supplied approximately 45% of normal blood flow and regional function, and both were improved by regulation of backward flow. Therefore, a conduit from the left ventricle to an epicardial vessel could serve as a rapidly deployable means of revascularizing totally occluded coronary vessels for which suitable natural conduits are not available.

The role of angiotensin II AT1 receptor in the maintenance of hemodynamics in a canine model of coronary microembolization-induced heart failure

The purpose of this study was to determine whether Angiotensin II (Ang II) contributes to the regulation of resting hemodynamics via Ang II type 1 (AT1) receptors in awake dogs with coronary microembolization-induced heart failure. Six dogs were surgically instrumented for measurement of systemic hemodynamics and for coronary microembolization. The acute hemodynamic effects of a selective AT1-receptor antagonist, GR138950 (1 mg/kg, i.v.), were determined before and after congestive heart failure (CHF). GR138950 had no effects on hemodynamics before CHF Daily coronary microembolizations (through the previously implanted coronary catheter) resulted in CHF, as documented by hemodynamic measurements, a slight but significant increased Ang II plasma level (17.4 +/- 1.6 vs. 23 +/- 1.0 pg/ml; p < 0.05), and characteristic clinical signs of CHF. After CHF, GR138950 significantly increased left ventricular dP/dt(max) (LVdP/dt(max)) from 1,754 +/- 68 to 2,347 +/- 114 mm Hg/s and decreased LV systolic pressure (LVSP) from 118 +/- 5 to 101 +/- 7 mm Hg; meanwhile, heart rate (from 132 +/- 4 to 102 +/- 6 beats/min) and LV end-diastolic pressure (LVEDP; from 17 +/- 3 to 9 +/- 1.5 mm Hg) were significantly decreased. Mean arterial pressure (MAP) was not affected. The peak effects occurred 90 min after administration. Thus Ang II contributes significantly to resting hemodynamics via AT1 receptors in this CHF model; that is, the specific AT1 blocker inhibits the negative inotropic actions of Ang II in the CHF state.

Hemodynamic effects of a calcium channel promoter, BAY y 5959, are preserved after chronic administration in ischemic heart failure in conscious dogs

BAY y 5959 is a dihydropyridine derivative that binds to L-type calcium channels in a voltage-dependent manner and promotes calcium entry into the cell during the plateau of the action potential by influencing mean open time. Because myofilament responsiveness to calcium is preserved in congestive heart failure (CHF), the inotropic responsiveness to this compound should be preserved in CHF, and tolerance should not develop despite long-term treatment. To test these hypotheses, CHF was induced in 14 chronically instrumented dogs by daily (30 +/- 5 days) intracoronary microsphere injections. The effects of BAY y 5959 (2-h i.v. infusions of 3 microg/kg/min and 10 microg/kg/min) were determined before heart failure, after heart failure was established and then 2 h after the end of a 5-day continuous BAY y 5959 intra-atrial infusion. Before CHF, the positive inotropic effect of BAY y 5959 at a dose of 10 microg/kg/min [left ventricular dP/dt (LVdP/dt) increased from 2955 +/- 132 mmHg to 4897 +/- 426 mmHg, P < .05] was associated with bradycardia (HR decreased from 92 +/- 4 to 78 +/- 6 b/min, P <.05), slight increases in mean arterial pressure (it increased from 100 +/- 2 mmHg to 113 +/- 5 mmHg, P <.05) and did not alter left ventricular end-diastolic pressure. In CHF, BAY y 5959 continued to induce dose-dependent increases in left ventricular systolic pressure, LVdP/dt and mean arterial pressure, as well as causing bradycardia and a significant decrease in left ventricular end-diastolic pressure. After a 5-day infusion of BAY y 5959, base-line LVdP/dt and left ventricular end-diastolic pressure improved. The responses of LVdP/dt and mean arterial pressure to BAY y 5959 were similar to those of the control state. The sustained responses in CHF and after long-term infusion suggest that BAY y 5959 may be an effective and potent inotropic agent for treatment of CHF that does not lead to tolerance to its positive inotropic effects.

Effect of BAY y 5959 on myocardial function and metabolism in normal and failing hearts

BAY y 5959 is a dihydropyridine derivative with positive inotropic actions mediated by a direct increase in intracellular calcium. We characterized the direct myocardial actions of this new agent in hearts isolated from seven normal dogs and from five dogs with repeated coronary microembolization-induced heart failure. Inotropic actions of BAY y 5959 were accompanied by little effect on duration of contraction and by prolongation of the monophasic action potential (MAP); in contrast, isoproterenol decreased contraction and MAP durations. Whereas inotropic responsiveness to isoproterenol was blunted in embolized hearts, these actions of BAY y 5959 were relatively preserved in the heart failure state. Isoproterenol increased heart rate, whereas BAY y 5959 had little effect. Changes in coronary vascular resistance also decreased similarly for isoproterenol and BAY y 5959. Finally, for comparable inotropy, increases in myocardial oxygen consumption were similar for isoproterenol and for BAY y 5959. In summary, preserved inotropic responsiveness and lack of positive chronotropic actions are two clinically favorable features of this type of inotropic agents compared with a typical beta-adrenergic agonist.

p53 mutations in esophageal tumors from a high incidence area of China in relation to patient diet and smoking history

Esophageal tumors from 29 patients residing in Guangzhou, China were examined for mutations in exons 5-8 of the p53 tumor suppressor gene and for p53 protein accumulation in tumor cell nuclei. Anamnestic data for each patient, which included information on family history of cancer, tobacco smoking, drinking of alcoholic beverages, and dietary habits such as consumption of pickled vegetables, were recorded. Screening of DNA from tumor cells microdissected from biopsies was performed by PCR amplification of p53 gene exons 5-8, denaturing gradient gel electrophoresis analysis, and DNA sequencing. Mutations were identified in 20 of 29 tumors (69%). All tumors harboring a missense mutation in the p53 gene also showed nuclear accumulation of the tumor suppressor protein by immunohistochemistry. The most common p53 mutations in these tumors were guanine to adenine (G-->A) transitions (10 of 20 tumors; 50%). We did not find multiple mutations at codon 176, in contrast to Lung et al. in their recent study of esophageal cancer patients from Guangzhou (M. L. Lung et al., Cancer Epidemiol. Biomark. Prev., 5: 277-284, 1996). The mutation prevalence was high both in smokers (13 mutations in 20 smokers; 65%) and in nonsmokers (7 of 9 tumors with mutations; 78%), an observation that differs from that of studies in European and North American patients, which demonstrate a much higher prevalence of p53 mutations in smokers than in nonsmokers (reviewed in R. Montesano et al., Int. J. Cancer Predict. Oncol., 69: 225-235, 1996.). Our findings in this pilot study of tumor suppressor gene mutations in patients from Guangzhou support a large body of epidemiological observations pointing to dietary mutagenic carcinogens peculiar to populations in China at high risk of esophageal cancer.

Functional consequences of acute collagen degradation studied in crystalloid perfused rat hearts

OBJECTIVES

The impact of acute collagen disruption by the disulfide donor, 5,5'-dithio-2-nitrobenzoic acid (DTNB) on ventricular properties was tested in rat hearts.

METHODS

Collagen was degraded acutely in 13 isolated, isovolumically contracting rat hearts by perfusion with 1 mM DTNB added to Krebs-Henseleit solution for 1 hour followed by 2-hour perfusion with normal solution. Another 13 hearts were perfused with normal solution for 3 hours (Control).

RESULTS

Collagen content was 3.5 +/- 0.5% of ventricular dry weight in control group compared with 2.1 +/- 0.4% in DTNB group (decrease by 40%, p < 0.01). Scanning electron micrographs revealed loss of the delicate collagen network surrounding muscle fibers in DTNB treated hearts. Developed pressure at a fixed volume decreased to 86 +/- 17% of the baseline value after 3-hour perfusion in the control group, whereas in DTNB treated hearts developed pressure fell to 68 +/- 13% (p < 0.01). End-diastolic pressure was set at 5 mmHg at the beginning of the experiment and rose to 15 +/- 8 mmHg in control and 30 +/- 13 mmHg (p < 0.01) in the treated hearts. Concomitantly, wet-to-dry weight ratio increased from 5.63 +/- 0.26 in control to 6.07 +/- 0.11 (p < 0.05) in the DTNB treated hearts. A separate set of experiments on isolated myocytes excluded the possibility of a direct effect of DTNB on myocyte contractile function.

CONCLUSIONS

These data suggested that with 40% collagen disruption by DTNB there is a significant increase in tissue edema that results in a decrease in chamber capacitance; in addition, there is a significant decrease in systolic performance which reflects the combined effect of edema and loss of collagen.

Physiology, histology, and 2-week morphology of acute transmyocardial channels made with a CO2 laser

BACKGROUND

Transmyocardial revascularization with a CO2 laser appears to improve symptoms in patients with refractory angina. However, it remains controversial as to whether blood flow through the channels is the mechanism of benefit, especially in the acute setting.

METHODS AND RESULTS

Three protocols were used to test whether blood flows through transmyocardial CO2 laser revascularization channels. First, channels were made in excised, cross-perfused dog hearts (n = 5) using a CO2 laser (The Heart Laser; PLC Systems Inc, Milford, MA; 40 J/pulse) followed by ligation of the proximal left anterior descending coronary artery. Colored microspheres injected into the left ventricular chamber failed to detect any significant transmyocardial blood flow. In the second protocol (n = 4), laser channels were created in the left anterior descending artery territory, the left anterior descending artery was ligated, and the hearts were excised after 24 hours. Triphenyltetrazolium chloride staining revealed that no viable myocardium was detected around the laser channels in the ischemic myocardium. Finally, channels examined 2 weeks after creation in normal (n = 6) or ischemic (n = 4) myocardium did not maintain their original caliber but were invaded by granulation tissue, which included a large amount of smaller vascular spaces and vessels of various sizes.

CONCLUSIONS

Transmyocardial laser revascularization channels made with this CO2 laser did not provide acute myocardial perfusion or preserve myocardial viability in the face of acute ischemia. Channel morphology changes dramatically within the first 2 weeks. To the degree that these findings pertain to human myocardium, the results suggest that transmyocardial blood flow may not be the mechanism of benefit of this procedure, particularly in the acute setting.

Blood flow capacity via direct acute myocardial revascularization

The concept of direct myocardial revascularization, achieving myocardial perfusion through means other than the normal coronary vasculature, has a long history with the most widely investigated technique being the Vineberg procedure; current interest centers around the encouraging preliminary clinical results obtained with transmyocardial laser revascularization. Despite significant previous research, the acute blood flow potential through the direct myocardial route remains unknown. Nontransmural laser channels were made in the distal LAD territory from the epicardial surface of 5 mongrel dogs to which an internal mammary artery was connected. A flow probe was placed on the distal most portion of the artery and an intercostal branch was cannulated for infusion of colored microspheres. Measurements were taken under baseline conditions and following LAD and epicardial collateral ligation. Under all conditions, blood flow pattern was of a to-and-fro nature. At baseline, there was an average 0.60 +/- 0.24 ml/min net flow into the myocardium which was all contained within 0.5 cm of the central channel with a final myocardial perfusion of 0.011 +/- 0.016 ml/min/g. Following induction of ischemia average flow increased to 1.41 +/- 0.51 ml/min which extended as far as 1 cm from the channel with a final myocardial perfusion of 0.22 +/- 0.19 ml/min/g. In conclusion, a limited amount of acute myocardial perfusion can be achieved by the present technique of direct myocardial revascularization and the amount of flow is highly dependent upon the amount of flow through the native circulation.

Circulating anti-p53 antibodies in esophageal cancer patients are found predominantly in individuals with p53 core domain mutations in their tumors

Serum antibodies reacting with the tumor suppressor protein p53 have been detected previously in cancer patients with a variety of neoplasms. Two initial (although insufficient) prerequisites for a B-cell response to occur have been proposed: p53 protein accumulation in the tumor or a mutant p53 gene, or both. We have examined 65 esophageal cancer cases (42 from Guangzhou and Shenyang, People's Republic of China, and 23 from Paris, France) to obtain a prevalence estimate of anti-p53 antibodies for this type of cancer and to define the relationship of p53 tumor status to B-cell immune response. Sera were analyzed in a triplicate assay (enzyme-linked immunoassay, immunoprecipitation, and immunoblot) for anti-p53 antibodies. Tumor DNA was screened for mutations in exons 5-8, and tumor tissue was examined by immunohistochemistry for abnormal p53 protein accumulation. p53 mutations were found in 36 (58%) of 62 cases analyzed. Sixteen patients (25%) had circulating antibodies to the tumor suppressor protein. All but two (88%) of the tumors from seropositive cases had a mutation in the DNA binding region of the p53 gene, and with one exception, these tumors also showed nuclear accumulation of the p53 protein. In contrast, tumor mutations were found in just 22 (46%) of the 48 individuals in whom we did not detect anti-p53 antibodies. Among the 22 seronegative cases for which we found no tumor mutations, 11 revealed p53 protein accumulation by immunohistochemical analysis. Thus, circulating anti-p53 antibodies may be present in one-fourth of esophageal cancer patients, most of whom also would be expected to have a p53 gene mutation in their tumors. Patients without such mutations appear considerably less likely to mount a B-cell response to the p53 tumor suppressor protein than those that do (P < 0.01).

Does blood flow through holmium:YAG transmyocardial laser channels?

BACKGROUND

Early reports indicate that transmyocardial laser revascularization improves symptoms in patients with refractory angina. However, there is little experimental evidence of whether blood flow through channels is the mechanism of action.

METHODS

Endocardial channels were made in the distribution of the left anterior descending coronary artery in canine hearts (n = 5) using a holmium:yttrium-aluminum garnet laser. Hearts were excised acutely while perfused in a retrograde fashion from a second dog so that the aortic valve always remained closed. The proximal left anterior descending coronary artery was ligated. To measure direct transmyocardial blood flow, colored microspheres were injected into the left ventricular chamber.

RESULTS

The number of spheres per gram of tissue in the channel region was significantly higher than in the control region (low load, 302.5 +/- 169.0 versus 41.8 +/- 59.4; high load, 208.4 +/- 138.3 versus 5.8 +/- 11.7; both, p < 0.05). However, the estimated regional blood flow through the channels was extremely low (<0.01 mL/g/min. In the chronic setting (n = 4) (2-week survival), no flow as detected through the channels, and the endocardial entry points were closed.

CONCLUSIONS

Transmyocardial blood flow does not appear to occur through channels made with the holmium:yttrium-aluminum garnet laser. It remains to be determined whether this is the case with other types of lasers.

[Role of nucleus accumbens in cardiovascular activities and its relationship with opioid peptides in rats]

In this study, electrical stimulation and microinjection in nucleus accumbens in urethane-anesthetized rats were conducted to observe the effect of electrical stimulation of nucleus accumbens on blood pressure and heart rate. The following results were observed: (1) Electrical stimulation of the nucleus accumbens of rat resulted in significant hypotension and bradycardia. (2) Kainic acid microinjected into the nucleus accumbens, could abolish the effects mentioned above. (3) Naloxone administered to the nucleus accumbens could block the cardiovascular inhibitory effect evoked by electrical stimulation of nucleus accumbens. The intra-accumbens injection of mu-receptor agonist, DAGO could also elicit hypotension and bradycardia to an extent comparable to that of the effect due to electrical stimulation, whereas kappa-receptor agonist, U-50 had no such an effect. (4) When the cardiovascular inhibitory effect elicited by electrical stimulation of the nucleus accumbens was observed, the discharge activity in locus ceruleus was also decreased. (5) Bilateral vagotomy could abolish the change in heart rate elicited by the electrical stimulation of nucleus accumbens, but not the hypotension. It is suggested that the mu-opioid receptors of neurons in nucleus accumbens are involved in cardiovascular activity.

The intrastriatal 6-hydroxydopamine model of hemiparkinsonism: quantitative receptor autoradiographic evidence of correlation between circling behavior and presynaptic as well as postsynaptic nigrostriatal markers in the rat

Unilateral injections of 6-hydroxydopamine into the striatum resulted in almost immediate ipsilateral amphetamine (AMPH)- and delayed contralateral apomorphine (APO)-induced circling behavior in rats. APO-induced rotation correlated positively with that caused by AMPH. In these animals, there was an almost complete disappearance of dopamine uptake sites as well as increases in DA D2 receptors in specific subdivisions of the ipsilateral caudate-putamen (CPu). Both the rate of AMPH- and APO-induced rotation correlated with the percentage of DA terminal loss in the total aspect and in various quadrants of the striatum. In contrast, AMPH- and APO-induced rotation correlated with the percentage increase in striatal D2 receptors only in the dorsolateral (DL) aspect of the CPu. These results indicate that both AMPH- and APO-induced rotation can be used to determine the extent of DA terminal loss in the rat basal ganglia. The positive correlation of circling behavior to only changes in DA D2 receptors observed in the DL striatal subdivision provides further evidence for the heterogeneity of the basal ganglia. This model of hemiparkinsonism in the rat which uses a distant intrastriatal approach to the destruction of nigral DA cell bodies may be a more appropriate model to study the regenerative properties of the nigrostriatal DA system. This approach could also be used to more specifically localize peptidergic receptors on midbrain dopamine cell bodies.

p53 mutation and protein accumulation during multistage human esophageal carcinogenesis

Preinvasive lesions of squamous cell carcinoma are well defined morphologically and provide a model for multistage carcinogenesis. Since alterations in the p53 tumor suppressor gene occur frequently in invasive esophageal squamous cell carcinoma, we examined a set of preinvasive lesions to investigate the timing of p53 mutation. Surgically resected tissues from nine patients with esophageal squamous cell carcinoma contained precursor lesions which had not yet invaded normal tissues. Immunohistochemistry showed high levels of p53 protein in both preinvasive lesions and invasive carcinomas in six cases; sequence analysis of all invasive tumors identified p53 missense mutations in two cases. Preinvasive lesions from both tumors with mutations plus one wild-type tumor were microdissected and sequenced. In one patient there were different mutations in the invasive carcinoma (codon 282, CGGarg > TGGtrp) and a preinvasive lesion (codon 272, GTGval > T/GTGleu/val). In a second case, an invasive carcinoma had a mutation in codon 175 (CGCarg > CAChis), and adjacent preinvasive lesions contained a wild-type sequence. A carcinoma and preinvasive lesion from the third case contained high levels of protein and a wild-type DNA sequence. Therefore, p53 mutation may precede invasion in esophageal carcinogenesis, and multifocal esophageal neoplasms may arise from independent clones of transformed cells. The timing of p53 protein accumulation is favorable for an intermediate biomarker in multistage esophageal carcinogenesis.

Implantation of genetically modified mesencephalic fetal cells into the rat striatum

Transplantation of dopamine (DA) cells into the rat model of hemiparkinsonism induced by intranigral 6-hydroxydopamine (6-OHDA) injections has so far focused mainly on DA replacement via a pump-like mechanism. In the present study, we employed a model of hemiparkinsonism that uses an intrastriatal approach to lesioning the nigrostriatal DA pathway to assess the possibility of using cell transplantation to cause regeneration of that system. Toward that end, we transplanted two types of cells on the side of the 6-OHDA-induced lesions: 1) nonmodified fetal mesencephalic cells and 2) fetal mesencephalic cells that have been infected with a retrovirus vector containing a PKC beta 1 cDNA. Both types of cells cause behavioral improvement although the changes were more prominent and occurred earlier in the PKC-modified groups. Tyrosine hydroxylase (TH) immunocytochemistry revealed significantly cell survival in both groups of animals; in situ hybridization studies confirmed the continuous expression of TH mRNA in both groups. Interestingly, long TH-positive axons were observed only in the striata of animals implanted with PKC-modified cells. More importantly, surviving endogenous nigral TH-positive cell bodies were found only on the lesioned side in the latter group. The observations in these animals were associated with significantly smaller decreases in [3H]mazindol-labeled DA uptake sites in both the striata and substantia nigra pars compacta on the side ipsilateral to the 6-OHDA-induced lesions. Furthermore, immunohistochemical studies revealed increased gliosis in the striata of animals grafted with the PKC-modified cells. When taken together, these results indicate that transplantation of normal fetal mesencephalic cells can cause behavioral improvement by providing DA to the host striata whereas PKC-modified cells can, in addition, prevent the progressive degeneration of or cause regeneration of the dying nigrostriatal DA neurons in this model of hemiparkinsonism. These results are discussed in terms of their support for a role for second messenger systems and glial cells, as well as extracellular matrix molecules in the regeneration of the CNS.

Quantitative in situ hybridization evidence for differential regulation of proenkephalin and dopamine D2 receptor mRNA levels in the rat striatum: effects of unilateral intrastriatal injections of 6-hydroxydopamine

Nigrostriatal (NS) dopaminergic (DA) neurons are thought to exert an inhibitory influence on striatal enkephalinergic systems through their DA D2 receptors. In order to investigate the effects of partial lesions of the NS DA on striatal proenkephalin (PEK) and D2 receptor mRNAs, animals were allocated to High, Intermediate, and Low rotators on the basis of amphetamine-induced rotation observed after intrastriatal injections of 6-hydroxydopamine (6-OHDA). On the ipsilateral side of the lesions, there were significant increases in PEK mRNA in the total aspect of the caudate-putamen (CPu) of the High (+204%), the Intermediate (+125%), and of the Low (+67%) rotation groups in comparison to controls; these changes correlated positively with increases in rotation rate. Unexpectedly, there were also significant increases in striatal PEK mRNA on the contralateral side although these changes were much less prominent than those observed on the side of the lesions. Conversely, only the High rotation group showed significant increases (+112%) in D2 receptor mRNA which occurred only on the lesioned side. Interestingly, the low rotation group actually showed some non-significant decreases (-25%) on the side of the lesions. These results indicate that partial lesions of the NS DA projections are sufficient to cause substantial increases in PEK mRNA but not in D2 receptor mRNA. These data also provide evidence that the two nigrostriatal DA projections and the systems which they modulate might be under interdependent sets of controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Intrastriatal implants of fetal mesencephalic cells attenuate the increases in striatal proenkephalin mRNA observed after unilateral 6-hydroxydopamine-induced lesions of the striatum

Unilateral injections of 6-hydroxydopamine (6-OHDA) cause significant bilateral increases in striatal proenkephalin (PEK) mRNA in rat brain. We have tested the possibility that implantation of fetal mesencephalic cells can normalize these changes. Two types of grafts were used: 1) embryonic day-15 mesencephalic cells and 2) embryonic day-15 cells which have been modified with a retroviral vector containing a cDNA for protein kinase C (PKC). At two months after grafting, both cell types cause significant attenuation of the increases which occurred on the side of the lesion. However, only the PKC-modified cells cause normalization of the changes on the contralateral side. These observations indicate that, in addition to normalizing supersensitive striatal dopamine (DA) D2 receptors, embryonic cells can also attenuate the alterations in PEK mRNA observed after lesions of the nigrostriatal DA system. The finding that the PKC-modified cells caused bilateral effects in the striatum suggests that second messenger systems may play a role in the bilateral improvement reported in parkinsonian patients who had gotten unilateral intrastriatal transplants.

Archival analysis of p53 genetic and protein alterations in Chinese esophageal cancer

A strategy and methods for archival analysis of genetic and protein alterations in the p53 tumor-suppressor gene are presented. The tumor series includes 43 paraffin-embedded esophageal carcinomas from two high-incidence regions in the People's Republic of China. More than half contained elevated p53 protein levels which were detected by a high-titer polyclonal antiserum and a sensitive immunohistochemical method. To estimate the frequency of underlying mutations, DNA was isolated from conventional paraffin sections, amplified by the polymerase chain reaction, and examined by dideoxy termination sequencing. Analysis of exons 5-8 in a subset of 10 tumors revealed mis-sense point mutations in 4 out of 5 immunostain-positive tumors and a mutation encoding a stop codon in 1 of 5 immunostain-negative tumors. In this report of archival material, we conclude that detectable levels of p53 protein correlate closely with the occurrence of mis-sense mutations. Furthermore, these methods render large repositories of paraffin-embedded tumor and non-tumor tissues accessible to analysis. Immunohistochemical screening for elevated protein levels followed by sequence analysis represents an efficient strategy for the evaluation of the p53 mutational spectrum.

Long-term culture of human esophageal explants and cells

Human esophageal epithelium obtained from intermediate autopsies (less than 12 h) was maintained as cell and explant cultures. In order to develop a serum-free, defined media culture model, several medias and additives were evaluated. The viability and differentiation of the epithelial cells cultured with serum-free, Keratinocyte Growth Media (KGM, Clonetics Co., San Diego, CA) was improved over that of esophageal cells and explants cultured in either serum-supplemented CMRL 1066 (OCM), serum-free additive-supplemented CMRL 1066, or cimetidine-supplemented CMRL 1066. The KGM component EGF was determined to be trophic for esophagus cells on the basis of findings of increased 3H-TdR labelling in KGM cultures when compared to control cells grown in KGM without EGF (KBM). The morphologic pattern of the cytoskeletal proteins actin, keratin, and vimentin were characterized in isolated cell populations. The intermediate filaments, keratin, and vimentin were co-expressed in these epithelial cells. Esophageal explant viability, differentiation, and outgrowth from 15 cases were also evaluated in dishes coated with basement membrane associated proteins. Explants cultured in these dishes were equally well-preserved and differentiated. There were no significant differences in the explant histology when there was protein coating of the culture dishes, although one case showed improved outgrowth with laminin coating. A main advantage for using this culture system is that the same medium (KGM) can be used for both the culture of explants and isolated epithelial cells. Future applications of this model include determining: (1) the effect different concentrations of EGF and calcium in the media will have on esophageal proliferation and differentiation, and (2) the role of different basement membrane associated proteins on the plating efficiency of either isolated or outgrowth epithelial esophageal cells.

Development of a human stomach explant organ culture system to study the pathogenesis of Helicobacter pylori

These studies were undertaken to define conditions under which Helicobacter (formerly Campylobacter) pylori and viable human gastric mucosa could coexist in tissue culture with the ultimate goal of developing an in vitro experimental model which could be used to study interactions between H. pylori and gastric epithelium. Antral gastric biopsies obtained at upper endoscopy were placed in culture in either CMRL-1066 or keratinocyte growth media and incubated at 37 degrees C in either an oxygen-enriched environment (45% O2, 50% N2, 5% CO2) or a standard oxygen environment (95% air, 5% CO2). Without selective antibiotics to suppress growth of non-H.-pylori organisms, H. pylori could not be isolated from most initially positive tissue even after only 2 h in tissue culture; however, when selective antibiotics were utilized in the tissue culture media, H. pylori was isolated from 9 of 14 initially positive cases after 24-72 h in tissue culture. There was little difference in the morphology of either surface or glandular epithelium in H.-pylori-negative explants between time zero and 48-hour cultures. However, H.-pylori-positive explants after 48 h in tissue culture showed a significant increase in injury to both surface and glandular epithelium when compared to time zero specimens. These data demonstrate that viable H. pylori and human gastric epithelium can be maintained in explant organ culture and suggest that this gastric mucosal explant culture system may be useful in studying the significance of H. pylori infection of human gastric epithelia.

Hemorrheological investigation on healthy natives and immigrants at 3658 M above sea level in Lhasa

A hemorrheologic investigation on 186 healthy native and immigrants at an altitude of 3,658 M above sea level revealed that hemorrheologic indexes are statistically higher in males than in females irrespective of natives or immigrants, except that hemoglobin in male immigrants is higher than in male natives. For females, all indexes in immigrants are higher than in natives. In addition, the difference between males and females may be related to the function of androgen in polycythemia due to oxygen shortage.