Chinese expert consensus on imaging diagnosis of drug-resistant pulmonary tuberculosis

Tuberculosis (TB) remains one of the major infectious diseases in the world with a high incidence rate. Drug-resistant tuberculosis (DR-TB) is a key and difficult challenge in the prevention and treatment of TB. Early, rapid, and accurate diagnosis of DR-TB is essential for selecting appropriate and personalized treatment and is an important means of reducing disease transmission and mortality. In recent years, imaging diagnosis of DR-TB has developed rapidly, but there is a lack of consistent understanding. To this end, the Infectious Disease Imaging Group, Infectious Disease Branch, Chinese Research Hospital Association; Infectious Diseases Group of Chinese Medical Association of Radiology; Digital Health Committee of China Association for the Promotion of Science and Technology Industrialization, and other organizations, formed a group of TB experts across China. The conglomerate then considered the Chinese and international diagnosis and treatment status of DR-TB, China's clinical practice, and evidence-based medicine on the methodological requirements of guidelines and standards. After repeated discussion, the expert consensus of imaging diagnosis of DR-PB was proposed. This consensus includes clinical diagnosis and classification of DR-TB, selection of etiology and imaging examination [mainly X-ray and computed tomography (CT)], imaging manifestations, diagnosis, and differential diagnosis. This expert consensus is expected to improve the understanding of the imaging changes of DR-TB, as a starting point for timely detection of suspected DR-TB patients, and can effectively improve the efficiency of clinical diagnosis and achieve the purpose of early diagnosis and treatment of DR-TB.

[Classification, diagnosis and treatment status of pulmonary hypertension from 2012 to 2019: a single center study in Yunnan province]

Objective: To analyze the classification, diagnosis and treatment status of patients with pulmonary hypertension (PH) in Yunnan province. Methods: This was a retrospective study. Hospitalized patients with PH at Yan'an Affiliated Hospital of Kunming Medical University from January 2012 to December 2019 were enrolled. The clinical data of enrolled patients, including demographic data, comorbidities, targeted drug therapy, echocardiography and right heart catheterization results, were obtained through the electronic medical record system. The composition ratio of PH, diagnosis and treatment were analyzed. Results: A total of 13 590 patients with PH were enrolled, accounting for 3.09% (13 590/440 056) of the total number of hospitalizations during the same period. The composition of PH was predominantly pulmonary arterial hypertension (PAH) (55.50% (7 542/13 590)), followed by pulmonary hypertension (PH) caused by left heart disease (24.16% (3 284/13 590)). Among them, PAH could be subdivided into four types: idiopathic pulmonary arterial hypertension (IPAH), PAH associated with connective tissue disease, PAH associated with portal hypertension, and PAH associated with congenital heart disease (CHD-PAH), with CHD-PAH as the predominating type (98.09% (7 398/7 542). Patients with PAH were predominantly adolescents. In hospitalized patients with PH, from 2012 to 2019, the proportion of children and adolescents showed a decreasing trend from year to year, and the proportion of middle-aged and older adults showed a significant increasing trend, and the proportion of female patients showed a gradual decreasing trend, and the proportion of patients with comorbid hypertension, diabetes mellitus, coronary artery disease, arrhythmia, and pneumonia showed an increasing trend. A total of 1 034 patients (7.61% (1 034/13 590)) underwent right heart catheterization. The concordance rate between echocardiographic and right heart catheterization findings was (86.98% (875/1 006)). A total of 2 574 (18.94%) of PH patients were treated with PAH targeted drugs, of which 58.16% (1 497/2 574) were treated with monotherapy. Among the PH patients treated with PAH targeted drugs, the majority of patients were PAH patients (86.44% (2 225/2 574)), and 83.53% (2 150/2 574) patients treated with PAH targeted drugs were CHD-PAH. Conclusions: Hospitalized PH patients in our center between 2012 and 2019 are predominantly CHD-PAH, and the proportion of patients receiving right heart catheterization and targeted drug therapy is relatively low. The percentage of middle-aged and elderly PH patients shows an increasing trend from year to year, as well as the percentage of those with concomitant comorbidities.

Differences in Clinical and Imaging Features between Asymptomatic and Symptomatic COVID-19 Patients

OBJECTIVES

The clinical and imaging features of asymptomatic carriers of severe acute respiratory syndrome coronavirus 2 and symptomatic COVID-19 patients.

METHODS

The clinical and chest computed tomography imaging data of 47 asymptomatic carriers and 36 symptomatic COVID-19 patients were derived. All patients underwent 4-6 CT scans over a period of 2-5 days.

RESULTS

The bulk of asymptomatic carriers who developed symptoms and most of the COVID-19 patients were older than 18 years of age with a decreased lymphocyte count, abnormal hepatic and renal function, and increased D-dimer and C-reactive protein. In the early stage, the pulmonary lesion involved mostly 1-2 lobes at the peripheral area in asymptomatic carriers but more than three lobes at both the central and peripheral areas in COVID-19 patients. In the progression stage, the lesion of asymptomatic carriers extended from the peripheral to the central area, and no significant difference was found in the lesion range compared with the symptomatic control group. In early improvement stage, the lesion was rapidly absorbed, and lesions were located primarily at the peripheral area in asymptomatic carriers; contrastingly, lesions were primarily located at both the central and peripheral areas in symptomatic patients. Asymptomatic carriers reflected a significantly shorter duration from disease onset to peak progression stage compared with the symptomatic.

CONCLUSIONS

Asymptomatic carriers are a potential source of transmission and may become symptomatic COVID-19 patients despite indicating less severe pulmonary damage, earlier improvement, and better prognosis. Early isolation and intervention can eliminate such carriers as potential sources of transmission and improve their prognosis.

Dynamic Imaging Changes of COVID-19 Pneumonia at Different Stages

PURPOSE

To investigate the Computed Tomography (CT) imaging characteristics and dynamic changes of COVID-19 pneumonia at different stages.

METHODS

Forty-six patients infected with COVID-19 who had chest CT scans were enrolled, and CT scans were performed 4-6 times with an interval of 2-5 days.

RESULTS

At the early stage (n=25), ground glass opacity was presented in 11 patients (11/25 or 44.0%) and ground glass opacity mixed with consolidation in 13 (13/25 or 52.0%) in the lung CT images. At the progressive stage (n=38), ground glass opacity was presented in only one patient (1/38 or 2.6%) and ground glass opacity mixed with consolidation in 33 (33/38 or 86.8%). In the early improvement stage (n=38), the imaging presentation was ground glass opacity alone in three patients (3/38 or 7.9%) and ground glass opacity mixed with consolidation in 34 (34/38 or 89.5%). In the late improvement (absorption) stage (n=33), the primary imaging presentation was ground glass presentation in eight patients (8/33 or 24.2%) and ground glass opacity mixed with consolidation in 23 (23/33 or 69.7%). The lesion reached the peak at 4-16 days after disease onset, and 26 (26/38 or 68.4%) patients reached the disease peak within ten days. Starting from 6 to 20 days after onset, the disease began to be improved, with 30 (30/38 or 78.9%) patients being improved within 15 days.

CONCLUSION

COVID-19 pneumonia will progress to the peak stage at a mediate time of seven days and enter the improvement stage at twelve days. Computed tomography imaging of the pulmonary lesion has a common pattern from disease onset to improvement and recovery and provides important information for evaluation of the disease course and treatment effect.

Anti-IFN-γ autoantibodies underlie disseminated Talaromyces marneffei infections

Talaromyces marneffei causes life-threatening opportunistic infections, mainly in Southeast Asia and South China. T. marneffei mainly infects patients with human immunodeficiency virus (HIV) but also infects individuals without known immunosuppression. Here we investigated the involvement of anti-IFN-γ autoantibodies in severe T. marneffei infections in HIV-negative patients. We enrolled 58 HIV-negative adults with severe T. marneffei infections who were otherwise healthy. We found a high prevalence of neutralizing anti-IFN-γ autoantibodies (94.8%) in this cohort. The presence of anti-IFN-γ autoantibodies was strongly associated with HLA-DRB1*16:02 and -DQB1*05:02 alleles in these patients. We demonstrated that adult-onset acquired immunodeficiency due to autoantibodies against IFN-γ is the major cause of severe T. marneffei infections in HIV-negative patients in regions where this fungus is endemic. The high prevalence of anti-IFN-γ autoantibody-associated HLA class II DRB1*16:02 and DQB1*05:02 alleles may account for severe T. marneffei infections in Southeast Asia. Our findings clarify the pathogenesis of T. marneffei infection and pave the way for developing novel treatments.

Clinical and imaging features of pediatric COVID-19

BACKGROUND

Pediatric COVID-19 is relatively mild and may vary from that in adults. This study was to investigate the epidemic, clinical, and imaging features of pediatric COVID-19 pneumonia for early diagnosis and treatment.

METHODS

Forty-one children infected with COVID-19 were analyzed in the epidemic, clinical and imaging data.

RESULTS

Among 30 children with mild COVID-19, seven had no symptoms, fifteen had low or mediate fever, and eight presented with cough, nasal congestion, diarrhea, headache, or fatigue. Among eleven children with moderate COVID-19, nine presented with low or mediate fever, accompanied with cough and runny nose, and two had no symptoms. Significantly (P < 0.05) more children had a greater rate of cough in moderate than in mild COVID-19. Thirty children with mild COVID-19 were negative in pulmonary CT imaging, whereas eleven children with moderate COVID-19 had pulmonary lesions, including ground glass opacity in ten (90.9%), patches of high density in six (54.5%), consolidation in three (27.3%), and enlarged bronchovascular bundles in seven (63.6%). The lesions were distributed along the bronchus in five patients (45.5%). The lymph nodes were enlarged in the pulmonary hilum in two patients (18.2%). The lesions were presented in the right upper lobe in two patients (18.1%), right middle lobe in one (9.1%), right lower lobe in six (54.5%), left upper lobe in five (45.5%), and left lower lobe in eight (72.7%).

CONCLUSIONS

Children with COVID-19 have mild or moderate clinical and imaging presentations. A better understanding of the clinical and CT imaging helps ascertaining those with negative nucleic acid and reducing misdiagnosis rate for those with atypical and concealed symptoms.

[Treatment of Chilomastix mesnili infection with traditional Chinese medicine: a case report]

This paper reports a case with Chilomastix mesnili infections, and summarizes the diagnosis and treatment with traditional Chinese medicine.

[Association between fatty liver and type 2 diabetes in the baseline population of Jinchang Cohort]

Objective: To explore the association between fatty liver and type 2 diabetes mellitus (T2DM) in the baseline-population of Jinchang cohort study. Methods: Data from all the participants involved in the baseline-population of Jinchang cohort study was used, to compare the risks of T2DM in fatty liver and non fatty liver groups and to explore the interaction between family history or fatty liver of diabetes and the prevalence of T2DM. Results: Among all the 46 861 participants, 10 574 were diagnosed as having fatty liver (22.56%), with the standardized rate as 20.66%. Another 3 818 participants were diagnosed as having T2DM (8.15%) with standardized rate as 6.90%. The prevalence of T2DM increased in parallel with the increase of age (trend χ(2)=2 833.671, trend P<0.001). The prevalence of T2DM in the fatty liver group was significantly higher than that in the non-fatty liver group, both in men or women and in the overall population. Compared with the group of non-fatty liver, the risks of T2DM in fatty liver group were seen 1.78 times higher in males, 2.33 times in women and 2.10 times in the overall population, after adjustment for factors as age, levels of education, smoking, drinking, physical exercise, BMI, family history of diabetes and some metabolic indicators (pressure, TC, TG, uric acid, ALT, AST, gamma-glutamyl transferase). Date from the interaction model showed that fatty liver and family history of diabetes present a positive additive interaction on T2DM (RERI=1.18, 95%CI: 0.59-1.78; AP=0.24, 95%CI: 0.14-0.34; S=1.43, 95%CI: 1.21-1.69). Conclusions: Fatty liver could significantly increase the risk of T2DM and a positive additive interaction was also observed between fatty liver and family history of diabetes on T2DM. It was important to strengthen the prevention program on T2DM, in order to effectively control the development of fatty liver.

Prognostic value of miR-141 downregulation in gastric cancer

Previous research has shown that microRNA-141 (miR-141) expression levels are associated with survival in several types of cancer. In the present study, we investigated the clinical significance and prognostic value of miR-141 in gastric cancer. Paired tissue specimens (tumor and adjacent normal mucosa) from 95 patients with gastric cancer were obtained at the Department of General Surgery, Xiangya Hospital, Central South University from March 2009 to February 2014. The levels of miR-141 in cancerous and corresponding non-cancerous tissues were detected by quantitative reverse transcription-polymerase chain reaction. Associations between clinicopathological parameters and miR-141 expression were evaluated using chi-square tests. Overall survival was calculated and survival curves were plotted using the Kaplan-Meier method; differences between groups were compared using log-rank tests. Compared to the matched normal gastric mucosa, gastric cancer tissues had significantly lower miR-141 expression levels (P < 0.001). This decreased miR-141 expression was significantly associated with tumor differentiation (P = 0.044), positive lymph node metastasis (P = 0.010), distant metastasis (P < 0.001), and advanced tumor-node-metastasis (TNM) stage (P < 0.001). Furthermore, a significant relationship was found between miR-141 expression and overall survival (P = 0.012, log-rank test). Cox regression analysis revealed that lymph node metastasis (P = 0.003), distant metastasis (P = 0.001), TNM stage (P < 0.001), and miR- 141 expression (P = 0.007) were independent prognostic factors in patients with gastric cancer. Our data provide evidence that the downregulation of miR-141 may contribute to the aggressive progression and poor prognosis of human gastric cancer.

HAMI 3379, a CysLT2R antagonist, dose- and time-dependently attenuates brain injury and inhibits microglial inflammation after focal cerebral ischemia in rats

Cysteinyl leukotrienes (CysLTs) induce inflammatory responses by activating their receptors, CysLT1R and CysLT2R. We have reported that CysLT2R is involved in neuronal injury, astrocytosis, and microgliosis, and that intracerebroventricular (i.c.v.) injection of the selective CysLT2R antagonist HAMI 3379 protects against acute brain injury after focal cerebral ischemia in rats. In the present study, we clarified features of the protective effect of intraperitoneally-injected HAMI 3379 in rats. We found that HAMI 3379 attenuated the acute brain injury 24 h after middle cerebral artery occlusion (MCAO) with effective doses of 0.1-0.4 mg/kg and a therapeutic window of ∼1h. It attenuated the neurological deficits, and reduced infarct volume, brain edema, and neuronal loss and degeneration 24 and 72h after MCAO. RNA interference with i.c.v. injection of CysLT2R short hairpin RNA (shRNA) attenuated the acute injury as well. Also, HAMI 3379 inhibited release of the cytokines IL-1β, interferon-γ (IFN-γ), and tumor necrosis factor-α (TNF-α) into the serum and cerebrospinal fluid 24h after MCAO. Moreover, HAMI 3379 ameliorated the microglial activation and neutrophil accumulation in the ischemic regions, but did not affect astrocyte proliferation 72h after MCAO. In comparison, the CysLT1R antagonist pranlukast did not affect microglial activation and IFN-γ release, but inhibited astrocyte proliferation and reduced serum IL-4. Thus, we conclude that HAMI 3379 has a protective effect on acute and subacute ischemic brain injury, and attenuates microglia-related inflammation. CysLT2R antagonist(s) alone or in combination with CysLT1R antagonists may be a novel class of therapeutic agents in the treatment of ischemic stroke.

The new P2Y-like receptor G protein-coupled receptor 17 mediates acute neuronal injury and late microgliosis after focal cerebral ischemia in rats

G protein-coupled receptor 17 (GPR17), the new P2Y-like receptor, is phylogenetically related to the P2Y and cysteinyl leukotriene receptors, and responds to both uracil nucleotides and cysteinyl leukotrienes. GPR17 has been proposed to be a damage sensor in ischemic stroke; however, its role in brain inflammation needs further detailed investigation. Here, we extended previous studies on the spatiotemporal profiles of GPR17 expression and localization, and their implications for brain injury after focal cerebral ischemia. We found that in the ischemic core, GPR17 mRNA and protein levels were upregulated at both 12-24 h and 7-14 days, but in the boundary zone the levels increased 7-14 days after reperfusion. The spatiotemporal pattern of GPR17 expression well matched the acute and late (subacute/chronic) responses in the ischemic brain. According to previous findings, in the acute phase, after ischemia (24 h), upregulated GPR17 was localized in injured neurons in the ischemic core and in a few microglia in the ischemic core and boundary zone. In the late phase (14 days), it was localized in microglia, especially in activated (ED1-positive) microglia in the ischemic core, but weakly in most microglia in the boundary zone. No GPR17 was detectable in astrocytes. GPR17 knockdown by a small interfering RNA attenuated the neurological dysfunction, infarction, and neuron loss at 24 h, and brain atrophy, neuron loss, and microglial activation at 14 days after reperfusion. Thus, GPR17 might mediate acute neuronal injury and late microgliosis after focal cerebral ischemia.

Effects of methylprednisolone and aprotinin on phospholipase D activity of leukocytes in systemic inflammatory response induced by cardiopulmonary bypass

AIM

To investigate the role of leukocyte phospholipase D (PLD) in systemic inflammatory response induced by cardiopulmonary bypass (CPB) and the effects of methylprednisolone and aprotinin on leukocyte PLD activity.

METHODS

Forty-two patients who received CPB open heart surgery were divided into 3 groups: methylprednisolone group, aprotinin group, and control group. Arterial blood (10 mL) was collected for assay of leukocyte PLD activity, myeloperoxidase (MPO) activity, and CD11b expression at 8 different time points in perioperative period. Plasma IL-6, IL-8, and C-reactive protein levels were also determined.

RESULTS

At the time point of ascending aorta declamped, leukocyte PLD activity for control group was (18 +/- 8) nmol choline . h-1 . mg-1, which was higher than that of pre-CPB (P < 0.01); the PLD activity for methylprednisolone group was (10 +/- 6) nmol choline . h-1 . mg-1 that was lower than control (P < 0.05), while it had no statistical difference compared with that of pre-CPB. In methylprednisolone group, PLD activity elevation was postponed to the time point of CPB stopped. There was no statistical difference in PLD activity between aprotinin group and control (P > 0.05). After administration of methylprednisolone or aprotinin, leukocyte CD11b expression, plasma IL-6, IL-8, C-reactive protein levels, and MPO activity decreased by different extent.

CONCLUSION

Leukocyte PLD activity was elevated significantly in systemic inflammatory response induced by CPB and methylprednisolone partially blunted the CPB-induced inflammatory response by inhibiting PLD activity.

[Role of phospholipase D in phagocytosis and exocytosis]

Mammalian phospholipase D(PLD) is a very important enzyme in the cellular signalling pathways. More and more lines of evidences suggest that PLD may be pivotal on multiple specialized steps in receptor-mediated phagocytosis and exocytosis. In this review, we will explore the recent advances on the role and the mechanism of PLD in phagocytosis and exocytosis.

MyoD-dependent induction during myoblast differentiation of p204, a protein also inducible by interferon

p204, an interferon-inducible p200 family protein, inhibits rRNA synthesis in fibroblasts by blocking the binding of the upstream binding factor transcription factor to DNA. Here we report that among 10 adult mouse tissues tested, the level of p204 was highest in heart and skeletal muscles. In cultured C2C12 skeletal muscle myoblasts, p204 was nucleoplasmic and its level was low. During myoblast fusion this level strongly increased, p204 became phosphorylated, and the bulk of p204 appeared in the cytoplasm of the myotubes. Leptomycin B, an inhibitor of nuclear export that blocked myoblast fusion, inhibited the nuclear export signal-dependent translocation of p204 to the cytoplasm. The increase in the p204 level during myoblast fusion was a consequence of MyoD transcription factor binding to several MyoD-specific sequences in the gene encoding p204, followed by transcription. Overexpression of p204 (in C2C12 myoblasts carrying an inducible p204 expression plasmid) accelerated the fusion of myoblasts to myotubes in differentiation medium and induced the fusion even in growth medium. The level of p204 in mouse heart muscle strongly increased during differentiation; it was barely detectable in 10. 5-day-old embryos, reached the peak level in 16.5-day-old embryos, and remained high thereafter. p204 is the second p200 family protein (after p202a) found to be involved in muscle differentiation. (p202a was formerly designated p202. The new designation is due to the identification of a highly similar protein-p202b [H. Wang, G. Chatterjee, J. J. Meyer, C. J. Liu, N. A. Manjunath, P. Bray-Ward, and P. Lengyel, Genomics 60:281-294, 1999].) These results reveal that p204 and p202a function in both muscle differentiation and interferon action.

Bronchodilating effects of bambuterol on bronchoconstriction in guinea pigs

AIM

To study the effects of bambuterol (Bam) on bronchoconstriction in guinea pigs.

METHODS

Bronchospasm induced by histamine aerosol, lung resistance (RL) and dynamic lung compliance (Cdyn) changes induced by ovalbumin aerosol in vivo, isolated resting lung parenchyma strips, and carbamylcholine-induced tracheal constriction in vitro in guinea pig were investigated.

RESULTS

Bam dose-dependently prolonged the time to histamine-induced collapse, ED50 values (95% confidence limits) of Bam intragastric gavage (i.g.) after 1 h, 4 h, and 24 h were 0.74 (0.60-0.91), 0.75 (0.61-0.91) and 1.00 (0.77-1.30) mg.kg-1, respectively. Bam 2 or 10 mg.kg-1 i.g. 2 h before ovalbumin aerosol partly or almost completely inhibited bronchial challenge of ovalbumin-induced change of RL and Cdyn. Bam 0.1-1.0 mumol.L-1 gave a weak relaxation on isolated tracheal strips induced by carbamylcholine and failed to relax the isolated resting lung parenchyma strips in guinea pig.

CONCLUSION

Bam showed a long-acting bronchodilation by its slow metabolism in vivo.

Mechanistic studies of initiator-initiator interaction and replication initiation

Unlike the chromosome of Escherichia coli that needs only one replication initiator protein (origin recognition protein) called DnaA, many plasmid replicons require dual initiators: host-encoded DnaA and a plasmid-encoded origin recognition protein, which is believed to be the major determinant of replication control. Hitherto, the relative mechanistic roles of dual initiators in DNA replication were unclear. Here, we present the first evidence that DnaA communicates with the plasmid-encoded pi initiator of R6K and contacts the latter at a specific N-terminal region. Without this specific contact, productive unwinding of plasmid ori gamma and replication is abrogated. The results also show that DnaA performs different roles in host and plasmid replication as revealed by the finding that the ATP-activated form of DnaA, while indispensable for oriC replication, was not required for R6K replication. We have analyzed the accessory role of the DNA bending protein, integration host factor (IHF), in promoting initiator-origin interaction and have found that IHF significantly enhances the binding of DnaA to its cognate site. Collectively, the results further advance our understanding of replication initiation.

[Rolipram reversed salbutamol tolerance in guinea pig trachea]

Studies were carried out to examine the role of phosphodiesterase(PDE) III and PDE IV in the development of tachyphylaxis of isolated guinea pig trachea to beta 2 adrenoceptor agonists. Treating trachea with salbutamol(SB) 1 mumol.L-1 for 1 h produced a 5-fold rightward shift of the SB concentration-response curve for the spasmolytic effect against methacholine-induced bronchocontraction and decreased the maximum SB-induced relaxation by 30%, i.e. induced tolerance of airway response of SB in vitro. The PDE IV inhibitor rolipram (Rol, 1 mumol.L-1, IC50), but not the PDE III inhibitor siguazodan (SK&F 94836, 1 mumol.L-1, IC50), reversed the SB tolerance. However, the protein synthesis inhibitor cycloheximide(10 mumol.L-1) did not abolish the SB tolerance. These results indicate that the SB tolerance may be related to increase in PDE IV activity.

Direct physical interaction between DnaG primase and DnaB helicase of Escherichia coli is necessary for optimal synthesis of primer RNA

The primase DnaG of Escherichia coli requires the participation of the replicative helicase DnaB for optimal synthesis of primer RNA for lagging strand replication. However, previous studies had not determined whether the activation of the primase or its loading on the template was accomplished by a helicase-mediated structural alteration of the single-stranded DNA or by a direct physical interaction between the DnaB and the DnaG proteins. In this paper we present evidence supporting direct interaction between the two proteins. We have mapped the surfaces of interaction on both DnaG and DnaB and show further that mutations that reduce the physical interation also cause a significant reduction in primer synthesis. Thus, the physical interaction reported here appears to be physiologically significant.

Release of glutamate and aspartate from CA1 synaptosomes: selective modulation of aspartate release by ionotropic glutamate receptor ligands

Synaptosomes prepared from area CA1 of the rat hippocampus were used to determine (a) whether Schaffer collateral-commissural-ipsilateral associational terminals release both aspartate and glutamate in a Ca(2+)-dependent manner when reuptake of released glutamate is minimal and (b) whether autoreceptor mechanisms described in CA1 or hippocampal slices could reflect direct actions of glutamate receptor ligands on the synaptic terminal. When challenged for 1 min with either 25 mM K+ or 300 microM 4-aminopyridine, CA1 synaptosomes released both glutamate and aspartate in Ca(2+)-dependent manner. The glutamate/aspartate ratio was approximately 5:1 in each case. K(+)-evoked glutamate release was unaffected by ligands active at NMDA or (RS)-alpha-amino-3-hydroxy-5-methyl-4- isoxazolepropionate (AMPA) receptors. Unlike glutamate release, the release of aspartate was enhanced by NMDA, and this effect was blocked by D-2-amino-5-phosphonovalerate (D-AP5). Kainate selectively depressed and 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) selectively increased the K(+)-evoked release of aspartate. AMPA enhanced aspartate release, like the antagonist CNQX. When applied in the presence of diazoxide, which blocks the desensitization of AMPA receptors, AMPA and kainate both depressed aspartate release. These findings support the view that Schaffer collateral-commissural-ipsilateral associational terminals release aspartate as well as glutamate and that these two release processes are regulated by different autoreceptor mechanisms.

In vivo glycation of aldehyde reductase, a major 3-deoxyglucosone reducing enzyme: identification of glycation sites

We have reported that the enzyme which reduces 3-deoxyglucosone (3-DG), a major intermediate and a potent cross-linker in the Maillard reaction, is identical with aldehyde reductase [Takahashi, M., Fujii, J., Teshima, T., Suzuki, K., Shiba, T., & Taniguchi, N. (1993) Gene 127, 249-253]. The enzyme purified from normal rat liver was found to be partially glycated as judged by binding to a boronate column and reactivity to anti-epsilon-hexitol lysine IgG. Sites of in vivo glycation of rat liver aldehyde reductase were identified by sequencing of digested peptides labeled with NaB[3H]4 and by mass spectrometry. The major glycated sites were lysines 67, 84, and 140. The glycated enzyme had low catalytic efficiency (kcat/Km) as compared to the nonglycated form. In streptozotocin-induced diabetic rats, the glycated form was significantly increased in kidneys. Because the enzyme plays a role in detoxifying 3-DG formed through the Maillard reaction in vivo, glycation of aldehyde reductase and reduction of its activity may result in the metabolic imbalance under diabetic conditions.

[Effects of compatibility of radix Ginseng with faeces Trogopterori on toxicity in experimental animals]

The acute toxicity test in mice revealed no toxic effects after oral administration with mixed decoction of Radix Ginseng and Faeces Trogopterori. But a tendency of increasing toxicity was found with intraperitoneal injection. The subacute toxicity test in rats showed no obvious effect on white blood cell count (WBC), differential count (DC), platelet count (Pt), hemoglobin amount (Hb), serum glutamic pyruvic transaminase (SGPT), blood urea nitrogen (BUN), body weight (BW), and so on after oral administration with the above-said mixed decoction.