Biomedical subjects
Publications and source records attributed to Q Guo.
The results show that the following ecological requirements must be met for Pinellia ternata to grow well: warm climate (appropriately 10-27 degrees C), adequate humidity and scattering sunlight. Burning sunlight and high temperature, as well as waterlogging are harmful to its growth.
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PURPOSE: To determine levels of malate dehydrogenase (MDH), lactate dehydrogenase (LDH) and their isoenzymes in tears of normal Chinese subjects and patients with ocular surface disorders. METHODS: The age range of normal subjects was 10-88, with 136 male and 128 female subjects. 123 patients suffered from ocular surface disorders. Tears were collected from lower fornix on Xinghua filter disc (0.1mm thick, 5mm in diameter). The values of tear MDH and LDH were determined by MONARCH-2000 Analyzer (U. S. A.). Their isoenzymes were separated by acetate cellulose electrophoresis and were determined by Model CDS-200 light densitometer. RESULTS: The normal values of tear LDH and MDH were 45.51 + 23.00-81.35 + 37.84 umol.s-1/L and 11.00 + 5.33-19.50 + 9.17 umol.s-1/L respectively, disregarding sex or eye distriction (P > 0.05). The values of tear LDH and MDH in the group aged 10-19 were significantly lower than in another groups (P < 0.05). 95% normal ranges of tear MDH aged below 19 and above 20 were 3.63-19.90 umol.s-1/L and 4.20-36.64 umol s-1/L. 95% normal ranges of tear LDH aged below 19 and above 20 were 17.69-82.93 umol.s-1/L and 21.47-150.41 umol.s-1/L. The MDH isoenzymes comprised MDHs and MDHm, the former accounting for 80.0-89.1%. The LDH isoenzymes comprised 5 varieties, of which the ratio H/M of subunit H to subunit M was 0.196 + 0.02. Levels of tear LDH,MDH and their isoenzymes in different diseases were various. CONCLUSIONS: Tear LDH/MDH ratio reflected sensitively the metabolism of corneae and conjunctival epithelium. The changes in LDH isoenzymes were helpful to the differential diagnosis of external eye diseases, and the increase of MDHm reflected sensitively the degree of injury to the corneal epithelium.
The effect of Astragalus membranaceus (AM) on Ca2+ influx across the myocardial plasma membrane and coxsackie virus B3(CVB3)-RNA replication in cultured neonatal rat heart cells infected with CVB3 was investigated. It was found that the Ca2+ influx could be inhibited significantly (P < 0.01) by AM after infection of heart cells for 48 h. In addition, when the cultured heart cells infected with CVB3 and treated with AM for 48 h, the Ca2+ influx of infected heart cells also could be inhibited by AM (P < 0.05) and the amounts of CVB3-RNA in myocytes were significantly decreased than that in infected control group (P < 0.001). These phenomena suggested that AM could exert the effects of decreasing the secondary Ca2+ damages, and improving the abnormal myocardial electric activity, and inhibiting replication of CVB3-RNA in myocardium. Thus, it is a rational choice to treat patients with AM in viral myocarditis.
AIM: To study the changes of hippocampal quinolinic acid (QA) concentrations during acute and chronic seizures induced by ip injection of kainic acid (KA, 12 mg kg-1) in rats. METHODS: The extraction and measurement of QA in the hippocampus were performed using a gas chromatography-mass spectrometry method. RESULTS: When acute seizures were fully established 3 h after KA injection, no significant changes of hippocampal QA were found. During chronic seizures observed on d 30 after KA injection, there was even a 55 +/- 8% significant decrease. When neither acute nor chronic seizures were detectable but astroglial proliferation in the hippocampus and secondary neuronal degeneration in extrahippocampal regions became gradually prominent 2 d and 7 d after KA injection, there were 56 +/- 13% and 156 +/- 13% dramatic increases of hippocampal QA concentrations, respectively. CONCLUSION: The increase of hippocampal QA hardly plays any key role in the initiation of KA-induced seizures but may contribute to astroglial proliferation and neuronal degeneration by activation of N-methyl-D-aspartate receptors.
We previously reported that Qingyangshen (QYS), a traditional Chinese medicine with antiepileptic property, had therapeutic effect on kainic acid (KA) induced experimental seizures (see JTCM 13 (4): 281-286, 1993 for reference). To investigate the mechanisms underlying the anticonvulsant action of QYS, we analyzed the modulatory effect of QYS on rat hippocampal c-fos proto-oncogene expression during KA-induced epileptogenesis in this and the following paper. The expression of hippocampal c-fos gene during KA-induced seizures were examined first. Rats were intraperitoneally injected with kainic acid (KA, 12 mg/kg) and hippocampal c-fos mRNA level was determined by Northern blot analysis during both acute (within one day after KA injection) and chronic (15 days after KA treatment) seizures. A mild increase in hippocampal c-fos mRNA level was observed 30 min after KA injection (being 1.98 +/- 0.70 times of control level), which corresponded temporally to the occurrence of the first limbic seizures. There was an 11.02 +/- 3.33 fold maximal induction of c-fos mRNA at 2 h after KA administration, which remained relatively stable even when behavioral seizures continued to aggravate 4 h after KA treatment. Twelve hours after KA administration, c-fos mRNA in the hippocampus returned to control level when acute seizures began to gradually disappear. In contrast, the induction of hippocampal c-fos mRNA during chronic seizures was inhibited significantly, being reduced by 55.40% compared to control. This suggested that c-fos is in different functional states at acute and chronic stages of epileptogenesis induced by KA.
A monoclonal antibody AB-3 has been used immunohistochemically in a retrospective study of formalin-fixed paraffin embedded tissues of the salivary gland malignant pleomorphic adenomas (MPA). Positive staining was found in 25/60 (41.67%) of MPA. c-erbB-2 oncoprotein expression of the postoperative recurrent MPA group was higher than that of non-recurrent MPA group (P < 0.05). The postoperative 5-year survival rate of MPA with c-erbB-2 expression was considerably lower than that of without expression (P < 0.01). This observation indicates that c-erbB-2 oncoprotein expression may be an useful prognostic indicator in MPA.
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Group I introns are highly structured RNAs which catalyse their own splicing by guanosine-initiated transesterification reactions. Their catalytic core is generally stabilized by RNA-RNA interactions within the core and with peripheral RNA structures. Additionally, some group I introns require proteins for efficient splicing in vivo. The Neurospora CYT-18 protein, the mitochondrial tyrosyl-transfer RNA synthetase (mt TyrRS), promotes splicing of the Neurospora mitochondrial large ribosomal RNA (LSU) and other group I introns by stabilizing the catalytically active structure of the intron core. We report here that CYT-18 functions similarly to a peripheral RNA structure, P5abc, that stabilizes the catalytic core of the Tetrahymena LSU intron. The CYT-18 protein and P5abc RNA bind to overlapping sites in the intron core, inducing similar conformational changes correlated with splicing activity. Our results show that a protein can play the role of an RNA structure in a catalytic RNA, a substitution postulated for the evolution of nuclear pre-messenger RNA introns from self-splicing introns.
We developed segmental Lp-TAE, which is transcatheter hepatic sub-subsegmental, subsegmental, or segmental chemoembolization using Lipiodol introduced into the tumor-bearing hepatic sub-subsegment, subsegment, or segment as the target area. A total of 98 patients with nonresectable hepatocellular carcinoma (HCC) undergoing segmental Lp-TAE (Seg-Lp-TAE) were studied, and the relationship between the CT pattern observed after Seg-Lp-TAE (Seg-Lp-CT) and the therapeutic results obtained in those patients was evaluated. Seg-Lp-CT was classified into four types (type I, homogeneous; type II, defective; type III, inhomogeneous; and type IV, only slight accumulation, if any) according to the Lipiodol accumulation pattern observed after Seg-Lp-TAE. The cumulative nonrecurrence rates of type I were higher than those of types II-IV. The cumulative survival rates of type Ia, in which Lp accumulation is also seen around the main tumor, were the highest (93.8% at 1 year, 85.9% at 2 years, 85.9% at 3 years, and 57.3% at 4 years). The cumulative survival rates achieved with Seg-Lp-TAE were 89.2% at 1 year, 69.4% at 2 years, 58.9% at 3 years, 44.0% at 4 years, and 30.2% at 5 years, which were higher than those achieved with conventional Lp-TAE. Seg-Lp-TAE is very useful in the treatment of HCC limited to one sub-subsegment, subsegment, or segment, and it is important to choose sub-subsegmental, subsegmental, or segmental Lp-TAE on the basis of the size and site of the tumor as well as the type and the number of feeding arteries.
The CHO cell temperature-sensitive mutant ldlF exhibits two defects in membrane traffic at the nonpermissive temperature (39.5 degrees C): rapid degradation of LDL receptors, possibly caused by endocytic missorting, and disruption of ER-through-Golgi transport. Here, we show that at 39.5 degrees C, the Golgi in ldlF cells dissociated into vesicles and tubules. This dissociation was inhibited by AlF4-, suggesting trimeric G proteins are involved in the dissociation mechanism. This resembled the effects of brefeldin A on wild-type cells. We isolated a hamster cDNA that specifically corrected the ts defects of ldlF cells, but not those of other similar ts mutants (ldlE, ldlG, ldlH, and End4). Its predicted protein sequence is conserved in humans, rice, Arabidopsis, and Caenorhabditis elegans, and is virtually identical to that of bovine epsilon-COP, a component of the coatomer complex implicated in membrane transport. This provides the first genetic evidence that coatomers in animal cells can play a role both in maintaining Golgi structure and in mediating ER-through-Golgi transport, and can influence normal endocytic recycling of LDL receptors. Thus, along with biochemical and yeast genetics methods, mammalian somatic cell mutants can provide powerful tools for the elucidation of the mechanisms underlying intracellular membrane traffic.
PURPOSE: To evaluate the usefulness of percutaneous hot saline injection therapy (PSIT) in the treatment of hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Twenty patients with HCC (23 nodules) underwent PSIT. Mean tumor diameter was < or = 30 mm. PSIT was performed by injecting hot saline into the HCC. The therapeutic effect of PSIT was evaluated with computed tomography, angiography, measurement of alpha-fetoprotein levels, and histopathologic examination of needle biopsy and resected specimens. RESULTS: No complications were encountered, and a therapeutic effect was obtained in all cases. When the injected material cools, it becomes physiologic saline making it possible to inject relatively large volumes in a single session. CONCLUSION: PSIT has promise as a form of curative local therapy for small HCCs and is expected to exert a safe and favorable therapeutic effect on large HCCs as well.
BACKGROUND AND PURPOSE: We sought to examine the effect of moderate hypothermia (30 degrees C to 32 degrees C) initiated after resuscitation on the scavenging systems of free radicals and lipid peroxidation in canine brain tissue after cardiac arrest and resuscitation. METHODS: Twenty-one dogs were divided into four groups: group A, nonischemic controls (shams) (n = 4); group B, 15-minute cardiac arrest without reperfusion (n = 4); group C, 15-minute cardiac arrest and standard resuscitation (n = 6); and group D, 15-minute cardiac arrest and hypothermic resuscitation (n = 7). During the period of 10 to 120 minutes after resuscitation, brain temperature and core temperature in group D remained at 30 degrees C to 32 degrees C and were 4 degrees C to 5 degrees C lower than in group C. For each dog, a sample of right parietal cerebral cortex was obtained from group A, group B, or from group C and group D at 2 hours after resuscitation. The sample was assayed for tissue malondialdehyde (MDA), the content of reduced glutathione (GSH), and the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX). RESULTS: In group B, a 15-minute cardiac arrest induced an increase in MDA, a significant reduction of GSH, and no change in SOD and GSH-PX activities compared with group A. In group C, there were further increases in MDA and reductions in GSH content and GSH-PX activity compared with group A; SOD activity remained substantially unchanged. The content of MDA was higher in group D than in group A but less elevated in group D than in group C. The GSH content and SOD and GSH-PX activities were significantly higher in group D than in group C. CONCLUSIONS: Moderate hypothermia initiated after resuscitation can significantly inhibit the accumulation of lipid peroxidation products and the consumption of free radical scavengers in the brain tissue.
The purpose of this study was to confirm the relationship of T1 and T2 relaxation rate vs. pO2 in vivo of 19F MR signal measured from intracellular perflubron. Our work to date has demonstrated that 1/T2 is more sensitive to pO2 than 1/T1 in the in vitro environment. The advantage of 1/T2 vs. 1/T1 is the speed of measurement and sensitivity. Seven alternating T1 and T2 measurements were obtained during a continuous acquisition using the TTISS pulse sequence. An abscess model was used for the in vivo experiments where rabbits were infused with 5ml/kg Oxygent HT 10 days prior to scanning. The abscess model was used because it has been shown that perflubron accumulates in macrophages located in the abscess wall. This technique thus provided signal from the intracellular milieu. The results of this study proved that pO2 monitoring by measuring T2 of 19F is feasible and can be used in-lieu of the T1 measurement. Given that the T2 measurement is much more rapid than the T1 measurement and that T2 changes are more sensitive than T1 changes with alterations in pO2, T2 should prove to be practical and useful for monitoring transient rapid changes in pO2.
The association between Body Mass Index (BMI) and mortality from all causes was investigated in a cohort study of 15827 citizens (aged 35 and over) in Shanghai. During about 3-year follow up the person-year mortality for men and women were 1311.78/100000 and 1036.87/100000, respectively. Cox regression analysis was conducted in a lower and an upper range of BMI, respectively. The inverse association between BMI and mortality in the lower range was statistically significant for men and women. The positive association between BMI and mortality in the upper range was highly statistically significant for women but not for men. Logistic regression analysis conducted over the entire range of BMI showed that BMI and all-cause mortality association was significantly "L"-shaped distribution for men and women. The mortality or relative hazard curve can be fit with quadratic model (Y = a-bX + cX2) in different sex.
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