General Carbon-Supporting Strategy to Boost the Oxygen Reduction Activity of Zeolitic-Imidazolate-Framework-Derived Fe/N/Carbon Catalysts in Proton Exchange Membrane Fuel Cells

The oxygen reduction reaction (ORR) activity of the Fe/N/Carbon catalysts derived from the pyrolysis of zeolitic-imidazolate-framework-8 (ZIF-8) has been still lower than that of commercial Pt-based catalysts utilized in the proton exchange membrane fuel cells (PEMFCs) due to low density of accessible active sites. In this study, an efficient carbon-supporting strategy is developed to enhance the ORR efficiency of the ZIF-derived Fe/N/Carbon catalysts by increasing the accessible active site density. The enhancement lies in (i) improving the accessibility of active sites via converting dodecahedral particles to graphene-like layered materials and (ii) enhancing the density of FeN_x active sites via suppressing the formation of nanoparticles as well as providing extra spaces to host active sites. The optimized and efficient Fe/N/Carbon catalyst shows a half-wave potential (E_1/2) of 0.834 V versus reversible hydrogen electrode in acidic media and produces a peak power density of 0.66 W cm^-2 in an air-fed PEMFC at 2 bar backpressure, outperforming most previously reported Pt-free ORR catalysts. Finally, the general applicability of the carbon-supporting strategy is confirmed using five different commercial carbon blacks. This work provides an effective route to derive Fe/N/Carbon catalysts exhibiting a higher power density in PEMFCs.

[Study on mechanisms of Th17/Treg imbalance in patients with cystic echinococcosis based on miRNA expression profiles]

OBJECTIVE

To investigate the serum microRNA (miRNA) expression and examine the impact of miRNA expression profiles on T helper type 17 (Th17)/regulatory T cells (Treg) imbalance among patients with cystic echinococcosis, so as to provide insights into the illustration of the mechanisms underlying chronic Echinococcus granulosus infections, and long-term pathogenesis.

METHODS

Total RNA was extracted from the sera of cystic echinococcosis patients and healthy controls, and subjected to high-throughput sequencing with the Illumina sequencing platform. Known miRNAs were annotated and new miRNAs were predicted using the miRBase database and the miRDeep2 tool, and differentially expressed miRNAs were identified. The target genes of differentially expressed miRNAs were predicted using the software miRanda and TargetScan, and the intersection was selected for Gene Ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Among the differentially expressed miRNAs with the 20 highest fold changes, miRNAs that targeted genes relating to key transcription factors RORC and FOXP3 that determine the production of Th17 and Treg cells or their important regulatory pathways (PI3K-Akt and mTOR pathways) were matched.

RESULTS

A total of 53 differentially expressed miRNAs were screened in sera of cystic echinococcosis patients and healthy controls, including 47 up-regulated miRNAs and 6 down-regulated miRNAs. GO enrichment analysis showed that these differentially expressed miRNA were involved DNA transcription and translation, cell components, cell morphology, neurodevelopment and metabolic decomposition, and KEGG pathway analysis showed that the differentially expressed miRNA were mainly involved in MAPK, PI3K-Akt and mTOR signaling pathways. Among the differentially expressed miRNAs with the 20 highest fold changes, there were 3 miRNAs that had a potential for target regulation of RORC, and 15 miRNAs that had a potential to target the PI3K-Akt and mTOR signaling pathways.

CONCLUSIONS

Significant changes are found in serum miRNA expression profiles among patients with E. granulosus infections, and differentially expressed miRNAs may lead to Th17/Treg imbalance through targeting the key transcription factors of Th17/Treg or PI3K-Akt and mTOR pathways, which facilitates the long-term parasitism of E. granulosus in hosts and causes a chronic disease.

[Analysis on incidence trend of liver cancer in China, 2005-2016]

Objective: To understand the incidence trend of liver cancer in China from 2005 to 2016, and explore the correlation between the incidence trend of liver cancer and the incidence trend of hepatitis B. Methods: The incidence data of liver cancer in China from 2005 to 2016 were collected from the Annual Report of Cancer Registry in China. The incidence data of hepatitis B were collected from China Public Health Science Data Center. World standardized incidence rate (WSR) was calculated according to the World Segi's population. Joinpoint regression model was used to analyze the trend of WSR of liver cancer [measured by average annual percentage change (AAPC)]. The age-period-cohort model was fitted to analyze the age, period and cohort effects in people aged 20- years and above. Pearson correlation coefficient was used to explore the correlation between the incidence of liver cancer and the incidence of hepatitis B. Results: The crude incidence of liver cancer in China showed a trend of first increase before 2009 and then relatively stable. The world standardized morbidity rate of liver cancer in China decreased from 19.11 per 100 000 in 2005 to 17.74 per 100 000 in 2016 (AAPC=-0.5%, 95%CI: -1.3%-0.3%, P=0.240). The incidence of liver cancer in male decreased significantly (AAPC=-1.0%, 95%CI: -1.5%--0.5%, P=0.001). The incidence of liver cancer in women increased from 2005 to 2010 [annual percentage change (APC)=1.7%, 95%CI: -0.1%-3.4%, P=0.059] but showed a significant decrease trend from 2010 to 2016 (APC=-1.6%, 95%CI: -2.3%--1.0%, P=0.001). From 2005 to 2016, the incidence of liver cancer showed a decreasing trend in urban areas (AAPC=-0.3%, 95%CI: -0.8%-0.3%, P=0.316) and rural areas (AAPC=-3.9%, 95%CI: -4.4%--3.3%, P<0.001). Risk for liver cancer increased with age, while the period effect showed a trend of first increase then decrease and cohort effect showed a decrease trend. The morbidity rates of both hepatitis B and liver cancer showed decrease trends from 2009 to 2016, and there was a significant correlation (r=0.71, 95%CI: 0.01-0.94, P=0.048). Conclusions: From 2005 to 2016, the morbidity rate of liver cancer in China showed a decrease trend, and there were significant gender and urban-rural area specific differences. Age effect had a great impact on the risk for liver cancer. With the progress of population aging in China, liver cancer is still a public health problem, to which close attention needs to be paid.

[Factors affecting the near-infrared autofluorescence intensity of parathyroid glands and intraoperative identification of parathyroid glands]

Objective: To evaluate the potential factors influencing the parathyroid autofluorescence intensity of near-infrared fluorescent (NIRF) and further value of NIRF in identifying the parathyroid during surgery. Methods: The clinical data of 51 patients who underwent thyroid or parathyroid surgery in the Department of Thyroid Surgery, the First Affiliated Hospital of Zhengzhou University from April to June 2019 were retrospectively analyzed, including 16 males and 35 females, aged 18 to 74 years.The fluorescence intensity (FI) of the parathyroid glands, thyroid glands and background, and the number of parathyroid glands detected by NIRF and white light were measured. Variance analysis, two independent samples t test and Spearman rank correlation analysis were used to analyze the relationship between standardized parathyroid FI and clinical variables. Chi square test was used to analyze the difference of parathyroid detection rate between NIRF and white light. Results: In the 51 patients, the mean standardized parathyroid FI was greater than the standardized thyroid FI (1.72 ± 0.68 vs. 1.25 ± 0.40, t=6.555, P<0.001). The standardized parathyroid FI was not associated with gender, age, operation type, BMI, preoperative serum Ca(2+), parathyroid hormone and calcitonin (all P>0.05), but it was associated with disease type (F=2.636, P<0.05). The mean standardized parathyroid FI of SHPT was lower than that of PTC, PTC with nodular goiter or NG(0.70±0.28 vs. 1.86±0.70, 1.69±0.49, 1.64±0.44, t value was 3.023, -1.129,-2.019, respectively, all P<0.05). There was no difference in the standardized parathyroid FI between SHPT and PHPT (1.34±0.18, t=1.218, P>0.05). There was no difference in standardized parathyroid FI between PHPT, PTC, NG, and PTC with NG(all P>0.05). Except for 3 cases of SHPT, 117 parathyroid glands were detected by NIRF and 101 parathyroid glands were detected by white light. The detection rate of parathyroid glands detected by NIRF was higher than that detected by white light (98.32% vs. 84.87%, χ(2)=13.974, P<0.001). In SHPT, the detection rate of parathyroid gland by NIRF was 25.00%. Conclusions: Except SHPT, parathyroid FI is not affected by other clinical variables. NIRF can improve the detection rate of parathyroid glands during operation.

Novel abdominal negative pressure lavage-drainage system for anastomotic leakage after R0 resection for gastric cancer

BACKGROUND

Anastomotic leakage (AL) is a severe complication associated with high morbidity and mortality after radical gastrectomy (RG) for gastric cancer (GC). We hypothesized that a novel abdominal negative pressure lavage-drainage system (ANPLDS) can effectively reduce the failure-to-rescue (FTR) and the risk of reoperation, and it is a feasible management for AL.

AIM

To report our institution’s experience with a novel ANPLDS for AL after RG for GC.

METHODS

The study enrolled 4173 patients who underwent R0 resection for GC at our institution between June 2009 and December 2016. ANPLDS was routinely used for patients with AL after January 2014. Characterization of patients who underwent R0 resection was compared between different study periods. AL rates and postoperative outcome among patients with AL were compared before and after the ANPLDS therapy. We used multivariate analyses to evaluate clinicopathological and perioperative factors for associations with AL and FTR after AL.

RESULTS

AL occurred in 83 (83/4173, 2%) patients, leading to 7 deaths. The mean time of occurrence of AL was 5.6 days. The AL rate was similar before (2009-2013, period 1) and after (2014-2016, period 2) the implementation of the ANPLDS therapy (1.7% vs 2.3%, P = 0.121). Age and malnourishment were independently associated with AL. The FTR rate and abdominal bleeding rate after AL occurred were respectively 8.4% and 9.6% for the entire period; however, compared with period 1, this significantly decreased during period 2 (16.2% vs 2.2%, P = 0.041; 18.9% vs 2.2%, P = 0.020, respectively). Moreover, the reoperation rate was also reduced in period 2, although this result was not statistically significant (13.5% vs 2.2%, P = 0.084). Additionally, only ANPLDS therapy was an independent protective factor for FTR after AL (P = 0.04).

CONCLUSION

Our experience demonstrates that ANPLDS is a feasible management for AL after RG for GC.

Hsa_circ_0000467 promotes cancer progression and serves as a diagnostic and prognostic biomarker for gastric cancer

BACKGROUND

Emerging evidence indicates that dysregulation of circular RNAs (circRNAs) is implicated in the development of malignancies. However, the diagnostic value and functional role of circRNAs in gastric cancer (GC) remain largely elusive.

METHODS

Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was performed to detect the expression of hsa_circ_0000467 in tissues, cell lines, and plasma. A receiver operating characteristic (ROC) curve was constructed to estimate the diagnostic value of hsa_circ_0000467. The association between the expression level of hsa_circ_0000467 and the clinicopathological features was analyzed. Moreover, cell functional assays were performed.

RESULTS

Hsa_circ_0000467 was significantly upregulated in GC tissue compared to adjacent nontumor tissue (n = 51, P < 0.05). Similar results were detected in the HGC-27, MGC-803, AGS, NUGC-3, GES-1 cell lines (n = 15, P < 0.001), and in the plasma samples from GC patients (n = 20, P < 0.05). The area under the ROC curve of hsa_circ_0000467 was 0.790, which is superior to commonly used biomarkers including CEA and CA-724. We found that the expression levels of hsa_circ_0000467 in the same patient were significantly lower after surgery (n = 20, P < 0.05). Moreover, the hsa_circ_0000467 expression level is closely associated with TNM stage. Additionally, Cox multivariate analysis showed that hsa_circ_0000467 is a novel independent prognostic factor. Furthermore, in vitro experiments demonstrated that knockdown of hsa_circ_0000467 markedly inhibited the proliferation, migration, and invasion of GC cells. Moreover, hsa_circ_0000467 silencing increased tumor apoptosis in vitro.

CONCLUSION

Hsa_circ_0000467 can act as a novel noninvasive biomarker for the diagnosis and prognosis of GC and may be a potential therapeutic target for GC.

CDK5 suppresses the metastasis of gastric cancer cells by interacting with and regulating PP2A

Several previous studies have demonstrated that cyclin‑dependent kinase (CDK)‑5 expression serves an important role in promoting the development of malignant tumours. We have previously reported that CDK5 suppresses gastric tumourigenesis. The aim of the present study was to investigate the mechanistic basis of CDK5. The results of immunoprecipitation and western blot analysis demonstrated that CDK5 could interact with serine/threonine‑protein phosphatase 2A (PP2A). The use of an inhibitor of PP2A in CDK5‑overexpressing gastric cancer (GC) cell lines antagonized CDK5‑mediated suppression in GC cells. Further analysis revealed that PP2A expression was downregulated in GC and patients with low levels of PP2A had worse survival outcomes than those with high levels of PP2A (P=0.035). Therefore, the present study provided a novel mechanism for CDK5‑mediated tumour suppression, suggesting that CDK5 may be an attractive target for future therapeutic strategies for treating GC. In addition, low levels of PP2A may indicate a tendency for poor prognosis in patients with GC.

[Progress in the diagnosis of florid cemento-osseous dysplasia]

Florid cemento-osseous dysplasia (FLCOD) is a rare, extensive bone metabolism disorder, which occurs only in the jaw bone. It is usually asymptomatic for a long time and discovered incidentally during a radiological examination. The characteristics of FLCOD in the initial stages are similar to those of periapical granuloma or jaw cyst, which may lead to misdiagnosis. After the lesion is mature, the imaging findings show that radiopaque with a thin radiolucent peripheral halo, which is crucial for the diagnosis of FLCOD, but other jaw lesions have similar imaging findings. Due to the poor blood supply of the lesion, the alveolar bone of root apices of vital teeth is slow to heal after trauma, increasing the chance of infection, which can lead to the osteomyelitis of the jaws and emerge sequestrum. This paper reviews the aspects of pathogenesis, clinical characteristics, diagnosis, differential diagnosis and treatment.

CDK5RAP3 suppresses Wnt/β-catenin signaling by inhibiting AKT phosphorylation in gastric cancer

BACKGROUND

CDK5RAP3 was initially isolated as a binding protein of the CDK5 activator p35. Although CDK5RAP3 has been shown to negatively regulate the Wnt/β-catenin signaling pathway in gastric cancer by repressing GSK-3β phosphorylation, its in-depth mechanism has not been determined.

METHODS

Following CDK5RAP3 overexpression or knock down, CDK5RAP3 signaling pathways were investigated in gastric cancer cells by Western Blotting. Cell growth, invasion and migration were also evaluated in gastric cancer cell lines. We analyzed CDK5RAP3, AKT, p-AKT (Ser473), GSK-3β and p-GSK-3β (Ser9) expression in gastric tumor samples and adjacent non-tumor tissues from 295 patients using immunohistochemistry and Western Blotting. The prognostic significance of CDK5RAP3 and p-AKT (Ser473) was confirmed by a Log-rank test.

RESULTS

Our study demonstrated that the expression of p-AKT (Ser473) and p-GSK-3β (Ser9) was negatively correlated with CDK5RAP3 in stable gastric cancer cell lines. CDK5RAP3 repressed AKT phosphorylation, which promoted GSK-3β phosphorylation, thereby suppressing β-catenin protein expression and, consequently, gastric cancer. The protein level of CDK5RAP3 was markedly decreased in most gastric tumor tissues compared with adjacent non-tumor tissues, and the levels of p-AKT (Ser473) and p-GSK-3β (Ser9) were also negatively correlated with those of CDK5RAP3. The prognostic value of CDK5RAP3 for overall survival was found to be dependent on AKT phosphorylation.

CONCLUSION

Our results demonstrated that CDK5RAP3 negatively regulates the Wnt/β-catenin signaling pathway by repressing AKT phosphorylation, which leads to better survival of patients with gastric cancer.

Promoting Ethylene Selectivity from CO2 Electroreduction on CuO Supported onto CO2 Capture Materials

Cu is a unique catalyst for CO₂ electroreduction, since it can catalyze CO₂ reduction to a series of hydrocarbons, alcohols, and carboxylic acids. Nevertheless, such Cu catalysts suffer from poor selectivity. High pressure of CO₂ is considered to facilitate the activity and selectivity of CO₂ reduction. Herein, a new strategy is presented for CO₂ reduction with improved C₂ H₄ selectivity on a Cu catalyst by using CO₂ capture materials as the support at ambient pressure. N-doped carbon (N_x C) was synthesized through high-temperature carbonization of melamine and l-lysine. We observed that the CO₂ uptake capacity of N_x C depends on both the microporous area and the content of pyridinic N species, which can be controlled by the carbonization temperature (600-800 °C). The as-prepared CuO/N_x C catalysts exhibit a considerably higher C₂ H₄ faradaic efficiency (36 %) than CuO supported on XC-72 carbon black (19 %), or unsupported CuO (20 %). Moreover, there is a good linear relationship between the C₂ H₄ faradaic efficiency and CO₂ uptake capacity of the supports for CuO. The local high CO₂ concentration near Cu catalysts, created by CO₂ capture materials, was proposed to increase the coverage of CO intermediate, which is favorable for the coupling of two CO units in the formation of C₂ H₄ . This study demonstrates that pairing Cu catalysts with CO₂ capture supports is a promising approach for designing highly effective CO₂ reduction electrocatalysts.

MAPK pathway regulated the cardiomyocyte apoptosis in mice with post-infarction heart failure

BACKGROUND

To explore the role of the MAPK signaling pathway in the cardiomyocyte apoptosis of mice with post-infarction heart failure (HF).

METHODS

Mice were divided into sham and myocardial infarction (MI) groups. Before surgery, the MI group was divided into SB203580 and PBS subgroups. A post-infarction HF model was established by ligating the left anterior descending coronary artery. Ventricular dilatation and cardiac function were observed by small animal echocardiography. The growth of primary cardiomyocytes was observed under an inverted phase contrast microscope. The mRNA and protein expressions of endoplasmic reticulum stress (ERS) markers, GRP78 and CHOP, were detected by qRT-PCR and immunofluorescence assay, respectively.

RESULTS

The MI group had enlarged left ventricle and decreased cardiac function. GRP78 and CHOP protein expressions in myocardial tissues, especially those of SB203580 subgroup, significantly increased (p < 0.05). The expressions of p-JNK and cleaved caspase 12 proteins, especially those of SB203580 subgroup, were significantly up-regulated. Cardiomyocytes of MI group were significantly more prone to apoptosis (p < 0.05), with SB203580 subgroup being more obvious.

CONCLUSION

MI was accompanied by ERS, probably involving the MAPK signaling pathway. SB203580, a specific inhibitor of this pathway, can relieve cardiomyocyte apoptosis and protect the myocardium by suppressing such stress (Tab. 3, Fig. 7, Ref. 20).

Effect of total peony glucoside pretreatment on NF-κB and ICAM-1 expression in myocardial tissue of rat with myocardial ischemia-reperfusion injury

Early recovery of myocardial perfusion is beneficial for myocardial ischemia. However, ischemia-reperfusion (I/R) may exacerbate myocardial injury. Research shows that total peony glucoside (TPG) can inhibit ischemic myocardial cell apoptosis. However, whether it can ameliorate I/R injury remains poorly understood. This study explored the effect of TPG pretreatment on I/R, through nuclear factor-kappa B (NF-κB) and intercellular adhesion molecule-1 (ICAM-1) expressions in I/R-affected myocardium. Healthy 7-week-old male Sprague Dawley rats were randomly categorized into sham operation (A), modeling (B), and 100, 200, and 400 mg/kg TPG pretreatment groups (C, D, and E, respectively), with 20 rats in each group. I/R rat models were designed by ligating left anterior descending coronary artery for 30 min to induce ischemia and for 120 min to induce reperfusion. Serum interleukin 6 (IL-6) and interleukin 8 (IL-8) levels were measured using enzyme linked immunosorbent assay. NF-κB and ICAM-1 mRNA and protein expressions were detected through RT-PCR and western blot analysis, respectively. Compared to group A, serum IL-6 and IL-8 levels of group B elevated significantly (P < 0.05), whereas NF-κB and ICAM-1 mRNA and protein expressions increased in the myocardium (P < 0.05). Serum IL-6 and IL-8 levels, and NF-κB and ICAM-1 mRNA and protein expressions, in myocardium of TPG groups reduced in a dose-dependent manner. Therefore, TPG pretreatment could alleviate myocardium reperfusion injury in I/R rat models by reducing NF-κB and ICAM-1 mRNA and protein expressions and cytokine secretions. This mechanism could be associated with the inhibition of NF-κB activation and downregulation of ICAM-1 expression.

Accurate high level ab initio-based global potential energy surface and dynamics calculations for ground state of CH2(+)

A global many-body expansion potential energy surface is reported for the electronic ground state of CH2 (+) by fitting high level ab initio energies calculated at the multireference configuration interaction level with the aug-cc-pV6Z basis set. The topographical features of the new global potential energy surface are examined in detail and found to be in good agreement with those calculated directly from the raw ab initio energies, as well as previous calculations available in the literature. In turn, in order to validate the potential energy surface, a test theoretical study of the reaction CH(+)(X(1)Σ(+))+H((2)S)→C(+)((2)P)+H2(X(1)Σg (+)) has been carried out with the method of time dependent wavepacket on the title potential energy surface. The total integral cross sections and the rate coefficients have been calculated; the results determined that the new potential energy surface can both be recommended for dynamics studies of any type and as building blocks for constructing the potential energy surfaces of larger C(+)/H containing systems.

A double-blind, placebo-controlled trial of extract of Ginkgo biloba added to haloperidol in treatment-resistant patients with schizophrenia

BACKGROUND

Many studies have indicated that excess free radical formation may be involved in the pathogenesis of patients with schizophrenia. Some investigators suggested that the use of free radical scavengers might provide improvement in schizophrenia. The aim of this study was to determine the effectiveness and to evaluate the side effects of extract of Ginkgo biloba (EGb) plus haloperidol in chronic, treatment-resistant inpatients with schizophrenia.

METHOD

One hundred nine patients meeting DSM-III-R criteria for schizophrenia completed a double-blind, placebo-controlled, parallel-group study of EGb plus haloperidol. Fifty-six of the patients were randomly assigned to receive a fixed dose of 360 mg/day of EGb plus a stable dose of haloperidol, 0.25 mg/kg/day, and 53 were assigned to receive placebo plus the same dose of haloperidol for 12 weeks. Patients were assessed using the Brief Psychiatric Rating Scale (BPRS), the Scale for the Assessment of Negative Symptoms (SANS), and the Scale for the Assessment of Positive Symptoms (SAPS) at baseline, week 6, and week 12 and the Treatment Emergent Symptom Scale (TESS) for side effects at week 12.

RESULTS

There was a significant reduction in both groups in BPRS total score after 12 weeks of treatment (p < .05). However, a significant reduction in total SAPS and SANS scores was noted in the EGb group (p < .05), but not in the placebo group. There was a lower SAPS total score in the EGb group than in the placebo group at the end of 12 weeks of treatment (p < .05). Of those treated with EGb plus haloperidol, 57.1% were rated as responders as compared with only 37.7% of those receiving placebo plus haloperidol when assessed by the SAPS (chi2 = 4. 111, p = .043). After 12 weeks of treatment, TESS subscore 1 (behavioral toxicity) and subscore 3 (symptoms of nerve system) were significantly decreased in the EGb group compared with the placebo group (p < .05).

CONCLUSION

EGb treatment may enhance the effectiveness of antipsychotic drugs and reduce their extrapyramidal side effects.

Risperidone versus haloperidol in the treatment of acute exacerbations of chronic inpatients with schizophrenia: a randomized double-blind study

The purpose of this study was to compare the efficacy and safety of risperidone and haloperidol in treatment-resistant chronic schizophrenic patients. Subjects (n = 78) who met DSM-III criteria for schizophrenia were randomly assigned to receive 6 mg/day of risperidone or 20 mg/day of haloperidol for 12 weeks. Clinical efficacy was determined using the Positive and Negative Syndrome Scale (PANSS), and side-effects with the Treatment Emergent Symptom Scale (TESS). Risperidone produced a mean 39.8 +/- 24.1% reduction in total PANSS score compared to a mean 28.3 + 19.4% reduction in the haloperidol group (P < 0.05). Analysis of changes for the three subscores of the PANSS revealed that the general psychopathology and negative subscores were significantly improved in the risperidone group compared to the haloperidol group. As for the side-effects, the risperidone group showed a significantly lower TESS total score, as well as nervous system symptoms subscore and cardiovascular symptoms subscore, compared to the haloperidol group. Risperidone appears to be a more effective and better tolerated antipsychotic drug in treatment-refractory Chinese schizophrenia than haloperidol.

Topiramate as a neuroprotectant in a rat model of global ischemia-induced neurodegeneration

The neuroprotective properties of topiramate were evaluated in a rat model of stroke in which neurodegeneration was induced by temporary global ischemia. In this model, the ischemia resulted from 11 min of cardiac arrest during atraumatic chest compression. Resuscitated rats exhibit a characteristic neurological syndrome characterized by sound-induced convulsions, specific motor and behavioral deficits, and death of hippocampal CA1 pyramidal neurons. Topiramate, when administered i.v. 30 min after resuscitation, reduced the degree of motor impairment (P< 0.05 vs control at doses of 10 and 20 mg/kg) and seizure severity (P< 0.05 vs control at a dose of 10 mg/kg on the fifth recovery day). The highest dose of topiramate (20 mg/kg i.v.) eliminated nearly all histologic signs of hippocampal ischemic neuronal injury (P< 0.001). Phenytoin at 20 mg/kg i.v. exhibited neuroprotectant effects similar to those observed for topiramate at 20 mg/kg i.v.. In normal rats, neither topiramate nor phenytoin at 20 mg/kg i.v. induced any apparent neurological impairment; however, at 40 and 60 mg/kg i.v. both induced a mild impairment typical of most anticonvulsants. The results of this study support the concept that topiramate possesses neuroprotective properties.

The effect of extract of ginkgo biloba added to haloperidol on superoxide dismutase in inpatients with chronic schizophrenia

The purpose of the study was to evaluate the effect of the classic antipsychotic haloperidol plus extract of ginkgo biloba (EGb) on treatment-resistant chronic schizophrenia and on blood superoxide dismutase (SOD) levels. Eighty-two patients with chronic refractory schizophrenia were studied. Forty-three patients were treated with haloperidol plus extract of ginkgo biloba (group 1), and 39 received haloperidol plus placebo (group 2). SOD levels of these patients were measured before and after treatment and were compared with SOD levels of 30 healthy volunteers. Therapeutic efficiency was equated with a change in clinical rating scores assessed by standardized measurement tools that included the Scale for the Assessment of Positive Symptoms and the Scale for the Assessment of Negative Symptoms (SANS) over this period. Patients in group 1 improved significantly as demonstrated by scores from these two assessment instruments; those in group 2 improved significantly only as shown by scores on SANS. SOD levels before treatment in all patients were significantly higher than those in healthy controls; after treatment, the SOD level decreased significantly in group 1 but not in group 2. These results suggest that EGb may enhance the efficiency of the classic antipsychotic haloperidol in patients with schizophrenia, especially on their positive symptoms, and that EGb may work through an antioxidant effect that is involved in the therapeutic mechanism in patients with chronic refractory schizophrenia.

[Determination of vitamin D2 included with beta-cyclodextrin complex in "longmu zhuanggu chongji" by HPLC]

In order to enhance the stability of vitamin D2(VD2), the inclusion complex of VD2 with beta-cyclodextrin(beta-CD) was added in "Longmu Zhuanggu Chongji", a medicine of children for the prevention and cure of rickets. The VD2 in beta-CD-VD2 inclusion complex was satisfactorily determined by both reversed-phase high performance liquid chromatography(HPLC) and ultraviolet spectrometry(UV). The experimental results from UV were in well consistent with those from HPLC. The accuracy and recovery of HPLC measurement were analyzed, and their relative standard deviation(RSD) were given to be 0.63% and 1.54%, indicating the method is quite correct and reliable, and the linear regression equation is reasonable. The "Longmu Zhuanggu Chongji" containing beta-CD-VD2 inclusion complexes was saponified by a mixture of KOH, vitamin C (VC) and alcohol-water(1:2, V/V) at 70 degrees C, then extracted with petroleum ether. An accurate content of the VD2 product was obtained by HPLC. A simple and rapid HPLC method, which can detect VD2 in the inclusion complex and in "Longmu Zhuanggu Chongji", has been established in this work.

Does dual infection by hepatitis B and C viruses play an important role in the pathogenesis of hepatocellular carcinoma in Japan?

BACKGROUND

There are contradictory data concerning the synergistic effect of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection on the progression from chronic hepatitis to hepatocellular carcinoma (HCC).

METHODS

To clarify the role of coinfection with HBV and HCV in the progression and pathogenesis of HCC, viral and clinicopathologic features were studied in 368 consecutive HCC patients at the University of Tokyo from 1991-1995.

RESULTS

Approximately 83% of patients (305 patients) were seropositive for the HCV antibody ("C-viral") and approximately 10% (37 patients) were positive for the hepatitis B surface antigen ("B-viral"). Positivity for both (dual infection) was found in only 2% of patients, and negativity for both in 5%. The incidence of dual infection in HCC patients was Similar to that in 549 patients with chronic hepatitis (1%) and 119 patients with cirrhosis (1%). Of the six HCC patients with dual infection, five patients were positive for the HBV early antigen and HBV DNA was less than measurable, whereas HCV RNA was detected and ranged from 10(3)-10(6) copies/50 microL of serum by competitive reverse transcriptase-polymerase chain reaction, and the clinical features resembled those of "C-viral" HCC. The remaining patient was early antigen positive and had HBV DNA by slot blot analysis, but the serum HCV RNA level was less than measurable. These data indicate that mutually exclusive viral replication occurred in patients with persistent coinfection. To further clarify further the possible involvement of HBV infection in "C-viral" HCC, HBV core antibody (HBcAb) was tested in 192 patients and was found to be positive in 111 and negative in 81. The serum HCV RNA level and clinicopathologic features (such as age and the severity of liver disease) were similar among the "C-viral" HCC patients irrespective of the presence or absence of HBcAb.

CONCLUSIONS

Based on these results, coinfection was found to be much less prevalent than generally is claimed, and even in a few HCC patients with the coinfection the mutually exclusive viral replication was noted, suggesting that coinfection plays little if any role in the development of HCC.

Further investigation on the role of selenium deficiency in the aetiology and pathogenesis of Keshan disease

Selenium supplements were not able to restore the ultrastructural changes in the myocardium of latent Keshan disease patients taken by using cardiac catheter endomyocardial biopsy. Observations on the changes of selenium status and the incidence of Keshan disease showed that new latent and naturally-occurring chronic cases were found in the endemic area even after selenium levels had been elevated in the residents to the levels typical in the non-endemic area. These results indicate that although selenium deficiency might be a primary pathogenetic geogen in the occurrence of Keshan disease, it is rather a conditional predisposing factor than a specific or initiative aetiologic factor for the occurrence of Keshan disease. Selenium supplementation could apparently alleviate the higher platelet responsiveness of residents in the endemic area, which might contribute to eliminating the basis for the occurrence of the multifocal perivascular necroses in myocardium of acute and subacute Keshan disease.

Outcome effects of different protective hypothermia levels during cardiac arrest in rats

BACKGROUND

Although hypothermia is widely used to protect the brain during cardiac and neurologic surgery, the optimal level of cooling has not been established. This study examined the protective effect of graded levels of surface cooling on cerebral function in rats after complete global cerebral ischemia.

METHODS

Groups of ketamine-anesthetized rats (13 animals in each group) were cooled to cranial temperatures of 34, 30, 27, 24, or 22 degrees C before circulatory arrest. Also a normothermic (37 degrees C) group was tested. After cooling, an 11-min circulatory arrest was produced by atraumatic chest compression. Circulatory arrest was followed by cardiopulmonary resuscitation and rewarming without postischemic intensive care. On the fifth postinsult day, neurologic outcome was scored on a 50-point neurodeficit scale (NDS 0 = normal). The percent of ischemic pyramidal neurons in the CA1 hippocampal region was also determined.

RESULTS

There were no survivors in the normothermic group. Neurologic recovery was enhanced with 30 degrees C cranial temperature, as compared to outcome in the 34 degrees C group. Further cooling did not change outcome. The neurodeficit scales were significantly lower in all other groups compared to the 34 degrees C group on the fifth postinsult day. The percent of ischemic neurons did not change significantly as a function of cooling, but the lowest count appeared at 27 degrees C.

CONCLUSION

In this model, moderate (30 degrees C) cooling improved neurologic outcome. There was no additional benefit from more extreme hypothermia.

Anticonvulsant activity of topiramate and phenytoin in a rat model of ischemia-induced epilepsy

Topiramate, a structurally novel anticonvulsant, and phenytoin were evaluated in a rat model of ischemia-induced epilepsy. In this model a transient global cerebral ischemia is induced by cardiac compression. By precisely controlling the experimental conditions the procedure causes reproducible neurological deficits that include audiogenic epileptic seizures. The seizures can be broadly separated into three types reflecting the degree of severity: wild running, clonic seizures, and tonic extension seizures of the forelimbs and hindlimbs. Topiramate and phenytoin blocked all three types of seizures. Calculated ED50 values for topiramate 1 hr after oral administration were 8.2, 13.0 and 36.1 mg/kg for blockade of tonic extension seizures, clonic seizures and wild running, respectively. Corresponding ED50 values for phenytoin were 5.0, 10.8 and 20.7 mg/kg. These results support the concept that the anticonvulsant activity of these drugs is due primarily to an ability to block the spread of seizures.

Detection of pulmonary and extrapulmonary tuberculosis patients with the 38-kilodalton antigen from Mycobacterium tuberculosis in a rapid membrane-based assay

A rapid membrane-based serologic assay using the 38-kDa antigen from Mycobacterium tuberculosis for the diagnosis of tuberculosis (TB) was evaluated with 201 patients with pulmonary TB, 67 patients with extrapulmonary TB, 79 Mycobacterium bovis BCG-vaccinated healthy controls, and 77 non-TB respiratory patients. The overall sensitivities, specificities, and positive and negative predictive values were, respectively, 92, 92, 84, and 96% for sputum-positive TB patients; 70, 92, 87, and 79% for sputum-negative TB patients; and 76, 92, 80, and 90% for extrapulmonary-TB patients. Only 2% (1 of 44) of the healthy control BCG-vaccinated subjects gave weak positive signals in the assay, indicating that this rapid serological assay is a valuable aid in clinical diagnosis for both pulmonary and extrapulmonary TB.

[Protection against experimental hepatic injury by fengxiang yigankang capsule]

Protective effect of Fengxiang Yigankang (FXYGK) capsule against hepatotoxicity induced by CCl4 and acetaminophen (AAP) was studied. It was found that the FXYGK capsule inhibited markedly malonic aldehyde (MDA) formation of liver induced by CCl4 and AAP. It blocked also depletion of reduced form of glutathione (GSH) of damaged liver induced by AAP. In addition, FXYGK could decrease serum alanine aminotransferase levels induced by CCl4 (P < 0.05). The results of histopathological examination showed that the FXYGK capsule (0.45, 0.9 and 1.8 g/kg) could also reduce significantly fatty degeneration of liver (P < 0.05).

Alteration of arteriolar responses to serotonin by two intravenous anesthetics

The effects of serotonin (5-HT) on the microvasculature of cremaster muscles were compared in decerebrate, ketamine- and pentobarbital-anesthetized rats. 5-HT-induced constriction of large distributing arterioles was enhanced in the ketamine- and pentobarbital-anesthetized rats. Precapillary arterioles of pentobarbital-anesthetized animals were more sensitive to 5-HT-induced dilation than either decerebrate or ketamine-anesthetized animals. The response of vessels to two 5-HT receptor antagonists (methysergide and LY53857) were unchanged by the anesthetics. Our findings suggest that both ketamine and pentobarbital enhance the microvascular response to 5-HT, but that these changes are not due to an alteration of receptor sensitivity.

[Effects of 4-(4"-(2",2",6",6"-tetramethyl-1"-pipe-ridinyloxy) amino)-4'-demethylepipodophyllotoxin on nucleic acids, proteins, and DNA strand of L7712 cells in vitro]

The antitumor activity of GP-7, a new spin-labeled epipodophyllotoxin, was studied by liquid scintillation spectrometry. There were many similarities between GP-7 and etoposide. Both GP-7 and etoposide inhibited the incorporation of [3H]TdR, [3H]UR, and [3H]Leu into DNA, RNA, and protein synthesis in leukemia 7712 cells. The inhibition correlated with drug concentration and duration. IC50 of GP-7 and etoposide on DNA synthesis at 24 h were 0.21 and 0.37 micrograms.ml-1, respectively. The inhibition of GP-7 or etoposide on DNA synthesis retained even after the drug were washed out for 3 h. GP-7 and etoposide caused DNA single-strand breaks, with a well concentration-response relationship. These data suggest that the inhibition of DNA synthesis by GP-7 or etoposide is likely due to the damage of DNA template and breaking of single-strand DNA.

Prostaglandin-related microvascular dilation in pentobarbital- and etomidate-anesthetized rats

Etomidate is characterized by minimal systemic cardiovascular effects, but its effect on the microvasculature has not been assessed. We compared the microvasculature of etomidate-anesthetized animals to that of animals anesthetized with pentobarbital, since its effects on the microvasculature are known. Male Sprague-Dawley rats were anesthetized with etomidate or pentobarbital. The cremaster muscle was prepared for microscopic viewing, leaving the neural and vascular supply intact. Small arterioles were near their maximal diameters in etomidate-anesthetized rats, whereas the pentobarbital group had a large dilator capacity (maximal diameter-basal diameter/basal diameter). The effect on resting arteriolar diameters of endothelium-derived relaxing factor (EDRF) and prostaglandin synthesis inhibitors was tested. Dilator capacity was not affected by the EDRF inhibitor nitro-L-arginine, but it was significantly increased by mefenamic acid and ibuprofen in etomidate-anesthetized animals. To test whether dilator and constrictor mechanisms were normal, serotonin concentration-response curves were obtained in pentobarbital and etomidate-anesthetized animals with and without mefenamate or ibuprofen present. The dilation of small arterioles to serotonin in the etomidate groups with mefenamate or ibuprofen was not significantly different from that of the pentobarbital groups. Serotonin produced a comparable constriction of large arterioles in both anesthetic groups. The topical application of etomidate to the cremaster muscle did not affect arteriolar diameters. Thus, etomidate appears to trigger the release of dilator prostaglandins in striated muscle through a central or indirect mechanism.

Halothane attenuates small arteriole vasodilation to serotonin (5-HT) in skeletal muscle

Inhaled anesthetics may have an effect on the microcirculation through selective alteration of receptor-mediated control. Halothane was chosen because its actions in the microcirculation have been determined previously. Serotonin has received recent attention as a potential mediator of vascular changes in a number of disease states. We obtained concentration-response curves for serotonin-induced constriction of large arterioles and dilation of small arterioles (less than 60 microns diameter) in the cremaster muscle of halothane-anesthetized and decerebrate rats. Cremaster muscles were prepared for microscopic viewing, leaving the neural and vascular supply intact. Serotonin concentration-response curves were obtained before and after receptor antagonist application. Large arteriole constriction was not affected by halothane. Dilation of small arterioles was decreased in halothane-anesthetized animals but enhanced in the presence of methysergide, a nonspecific antagonist. These data indicate that halothane interferes with occupancy of 5-hydroxytryptamine receptors.

Comparative evaluation of nine different methods for detecting enterotoxin of Escherichia coli

Nine different methods for detecting enterotoxin of Escherichia coli were studied and compared. We found rabbit ileal-loop test and suckling mouse assay were both quite accurate and reliable for detecting heat labile toxin (LT) and heat stable toxin (ST) of enterotoxigenic Escherichia coli (ETEC). Mouse ileal-loop test was simple, but its sensitivity and specificity were comparatively low. CHO cell-culture assay might be more sensitive and specific. LT-DNA probe was the most sensitive and specific method. In practical application, PIHT (plate immunohemolytic test), Biken's, SPA-CoA and ELISA methods are recognized as simple, rapid, sensitive and specific methods for detecting ETEC-LT. These methods can be selected for use in clinical laboratory.

[Antitumor activity of 4-(4''-(2'',2'',6'',6''-tetramethyl-1''-piperidinyoxy)amino)-4'- demethyl epipodophyllotoxin in vitro]

The antitumor activity of a new podophyllotoxin spin-labeled derivative, 4-(4''-(2'',2'',6'',6''-tetramethyl-1''-+piperidinyoxy)amino)-4'- demethylepipodophyllotoxin (GP-7) First synthesized by us, was studied in vitro. It was found that the proliferation of SGC-7901 cells was markedly inhibited by GP-7 depending the concentration and exposure time. At concentration of 0.04-100 mg/L, the inhibition rates were 15.5-92.6% ID50 was 0.42 mg/L. After exposure to GP-7 greater than 0.5 mg/L for 24, 48, 72 and 96 h, the inhibition rates of cells were 25.1, 49.0, 71.4 and 84.9% respectively. The dose-response curve of GP-7 on SGC-7901 cell was similar to that of etoposide (VP-16). The colony formation of SGC-7901 cell was also inhibited by GP-7 in a concentration dependent fashion with ID50 1.63 mg/L. At concentrations of 0.1-0.5 mg/L, the inhibitory effects were stronger than that of VP-16. GP-7 decreased the mitotic index (MI) of SGC-7901 cell and had no effect on microtubule assembly and disassembly in vitro, which suggested that GP-7 did not act on M phase.

[Podophyllic acid piperidyl hydrazone nitroxide radical and etoposide on nucleic acids and protein metabolism of leukemia L7712 cells in vitro]

Podophyllic acid piperidyl hydrazone nitroxide radical (GP-1) and etoposide (VP-16), derivatives of podophyllotoxin, inhibited DNA, RNA, protein and ATP synthesis of leukemia L7712 cells at a concentration of 5 micrograms/ml. Inhibitory extents were dependent on the exposure time from 3 to 24 h. The inhibitory rates of both drugs were about 15-66%. ID50 of GP-1 and VP-16 on the synthesis of L7712 cells at 24 h were 0.16 and 0.38 micrograms/ml, respectively. The dose-response curve of GP-1 was a parabolic one, while that of VP-16 was a straight line. The inhibition of GP-1 or VP-16 on DNA synthesis existed also after cells washing. It is suggested that the antitumor effects of GP-1 and VP-16 seem to be related to the damage of DNA template.

Anticancer drugs. II. Synthesis and biological evaluation of spin labeled derivatives of podophyllotoxin

The spin labeled derivatives of podophyllotoxin, 4-[4''-(2'',2'',6'',6''-tetramethyl-l''-piperidinyloxy)amino] -4'-demethylepipodophyllotoxin(GP-7,3) and N-podophyllic acid-N''-[4-(2,2,6,6-tetramethyl-l-piperidinyloxy)] thiosemicarbazide(GP-4,5) were synthesized and tested for their anticancer activity against the mouse solid tumors S180 and HepA in vivo, and the mouse lymphocytic leukemia L1210 and human stomach carcinoma SGC-7901 cells in vitro. At equitoxic concentrations, the anticancer activity of GP-7(3) was found to be similar to that of the clinically used VP-16(2). The toxicity of GP-7(3) (LD50231.2 mg/Kg) is 3.3 times lower than that of VP-16 (LD50 69.5 mg/Kg). GP-7(3) exhibits low subchronic toxicity. The total chemical yield of GP-7 (26%) is 4 times higher than that of VP-16 (6%) (based on podophyllotoxin). Therefore, GP-7(3) seems to be a promising new entry into the podophyllotoxin class of anticancer drugs.

Endemic goitre in central China caused by excessive iodine intake

Thyroid status was examined in children from two villages in central China where the iodine concentrations in drinking water were 462.5 and 54 micrograms/l. Goitres were present in 65% (n = 120) and 15.4% (n = 51), respectively. All children in both groups were clinically euthyroid and neurologically normal. Growth measurements and intellectual performance were similar in the two groups. Children from the high-iodine village had a lower mean serum triiodothyronine and higher serum free thyroxine and serum thyroid-stimulating hormone concentrations than the children from the control village. 2 cases of overt hypothyroidism were detected in the high-iodine village.