[Peroxidase assay over the course of dormancy relieving with low temperature in Fritillaria thunbergii Miq. by electrophoresis]

In order to study the physiological basis of dormancy relieving with low temperature in Fritillaria thunbergii, isoperoxidase changes of bud, adaxial epiderm and inner tissues in scale were assayed by means of electrophoresis over the course of dormancy relieving. All the patterns in bud and different parts of scale change at different stages, and the peroxidase activity in bud and adaxial epiderm is higher than that in the inner tissue of scale. These results indicate both bud and scale join in the dormancy relieving.

Calpain is a mediator of preservation-reperfusion injury in rat liver transplantation

Proteases as well as alterations in intracellular calcium have important roles in hepatic preservation-reperfusion injury, and increased calpain activity recently has been demonstrated in liver allografts. Experiments were designed to evaluate (i) hepatic cytosolic calpain activity during different periods of cold ischemia (CI), rewarming, or reperfusion, and (ii) effects of inhibition of calpain on liver graft function using the isolated perfused rat liver and arterialized orthotopic liver transplantation models. Calpain activity was assayed using the fluorogenic substrate Suc-Leu-Leu-Val-Tyr-7-amino-4-methyl coumarin (AMC) and expressed as mean +/- SD pmol AMC released/min per mg of cytosolic protein. Calpain activity rose significantly after 24 hr of CI in University of Wisconsin solution and further increased with longer preservation. Activity also increased within 30 min of rewarming, peaking at 120 min. Increased durations of CI preceding rewarming resulted in significantly higher activity (P < 0.01). Calpain activity increased rapidly upon reperfusion and was significantly enhanced by previous CI (P < 0.01). Calpain inhibition with Cbz-Val-Phe methyl ester significantly decreased aspartate aminotransferase released in the isolated perfused rat liver perfusate (P < 0.05). Duration of survival after orthotopic liver transplantation using livers cold-preserved for 40 hr was also significantly increased (P < 0.05) with calpain inhibitor. In conclusion, calpain proteases are activated during each phase of transplantation and are likely to play an important role in the mechanisms of preservation-reperfusion injury.

[Diastase and reducing sugar in Fritillaria thunbergii Miq. during the process of dormancy relieving with low temperature]

The changes of diastase's activity and reducing sugar's content in Fritillaria thunbergii were studied during the process of relieving dormancy with low temperature. The results showed that the metabolism in bud and scale was changed, the diastase's activity and reducing sugar's content of the adaxial epiderm were higher than those of the inner store tissue in the scale, but were approximate to those of the bud.

Messenger RNA release from ribosomes during 5'-translational blockage by consecutive low-usage arginine but not leucine codons in Escherichia coli

In '5'-translational blockage', significantly reduced yields of proteins are synthesized in Escherichia coli when consecutive low-usage codons are inserted near translation starts of messages (with reduced or no effect when these same codons are inserted downstream). We tested the hypothesis that ribosomes encountering these low-usage codons near the translation start prematurely release the mRNA. RNA from polysome gradients was fractionated into pools of polysomes and monosomes and a ribosome-free pool. New hybridization probes, called 'molecular beacons', and standard slot blots were used to detect test messages containing either consecutive low-usage AGG (arginine) or synonymous high-usage CGU insertions near the 5' end. The results show an approximately twofold increase in the ratio of free to bound mRNA when the low-usage codons were present in the message compared with when high-usage codons were present. In contrast, there was no difference in the ratio of free to bound mRNA when consecutive low-usage CUA or high-usage CUG (leucine) codons were inserted or when the arginine codons were inserted near the 3' end. These data indicate that at least some mRNA is released from ribosomes during 5'-translational blockage by arginine but not leucine codons, and they support proposals that premature termination of translation can occur in some conditions in vivo in the absence of a stop codon.

[Advancement on neurotransmitter transporters]

The neurotransmitter transporter (NTT), a kind of glycoprotein situating on the presynaptic membrane, glial membrane, or vesicle membrane, has become the focusing point of neuroscience research in recent years. They could combine selectively with transmitters released into synaptic cleft and carry them back into cells to aid the termination of synaptic transmission. In this way, NTT took an important part in modulation of information between neurons. Study on NTT has not been reported domestically. This article reviewed recent studies on molecular structure, classification, study methods, distribution, function, modulating factors and gene modulation, focus of study and also unresolved problems of NTT.

Development of the statocyst in the freshwater snail Biomphalaria glabrata (Pulmonata, Basommatophora)

The development of the statocyst of the freshwater snail Biomphalaria glabrata has been examined from embryo to adult. Special emphasis was put on the growth of the statoconia in the statocysts. In the statocysts of embryonic snails (90-120 h after oviposition) there is not a single statolith but an average of 40-50 statoconia per statocyst. The number of statoconia increases to 385-400 when the snails reach a shell diameter of 4 mm and remains relatively constant thereafter, irrespective of shell size. Small statoconia are found in supporting cells, which suggests that the statoconia are produced within these cells. The average diameter of statoconia and the total mass of statoconia increase with increasing shell diameter. The average number of large statoconia (diameter > 7 microm) per statocyst continues to increase from 2 to 10 mm animals while the number of small ones (diameter < 4 microm) initially rises and then decreases after 4 mm. These results demonstrate continuous growth of the statoconia in the cyst lumen of Biomphalaria. The single statoconia vibrate in a regular pattern in vivo, indicating beating of the statocyst cilia. The statoconia sink under the influence of gravity to load and stimulate receptor cells which are at the bottom. The length of cilia and the size of statocyst gradually increase as the animal grows. However, the increase in the volume of the statocyst is relatively small compared with the increase in body weight during normal development.

[Changes of soluble protein contents in Fritillaria thunbergii Miq. over the course of dormancy relieving with low temperature]

The changes of soluble protein contents in bud, adaxial cortex and inner tissue in the scale of Fritillaria thunbergii were assayed over the course of dormancy relieving with low temperature. There was a peak in each of the three diagrams at 25 days or 35 days treated with low temperature. All of the soluble protein contents of bud, adaxial cortex and inner tissue in scale tended to increased in the stage before dormancy relieving.

The structure of the statocyst of the freshwater snail Biomphalaria glabrata (Pulmonata, Basommatophora)

The structure of the statocyst of the freshwater snail Biomphalaria glabrata has been examined by light and electron microscopy. The two statocysts are located on the dorsal-lateral side of the left and right pedal ganglion. The statocysts are spherical, fluid-filled capsules with a diameter of approximately 60 microm for young and 110 microm for adult snails. The wall of the cyst is composed of large receptor cells and many smaller supporting cells. The receptor cells bear cilia which are evenly distributed on the apical surface. The cilia have the typical 9+2 internal tubule configuration. Striate rootlets originate from the base of the basal body and run downward into the cytoplasm. Side-roots arise from one side of the basal body and a basal foot from the other. For each receptor cell, the basal foot always points to the periphery of the surface, indicating that the receptor cell is non-polarized. The receptor cells contain cytoplasmic organelles such as mitochondria, ribosomes, rough and smooth endoplasmic reticulum, compact Golgi bodies and multivesicular bodies. Supporting cells bearing microvilli are interposed between the receptor cells. The junction complex between the supporting cells and the receptor cells is composed of adherens and septate junctions, while between supporting cells only the adherens junctions are present. The static nerve arises from the lateral side of the cyst and contains axons in which parallel neurotubules and mitochondria are found. The axons arise directly from the base of the receptor cells without synapse. In the cyst lumen there are unattached statoconia. The statoconia have a plate-like or concentric membranous ring structure. Based on the morphology, the function of the statocyst in Biomphalaria is discussed.

[Isoesterase assay over the course of dormancy relieving with low temperature in the seed of Fritillaria thunbergii Miq. by electrophoresis]

In order to study the physiological basis of dormancy relieving with low temperature in the seed of Frit-illaria thunbergii isoesterase patterns were assaved by means of electrophoresis over the courses of dormancy relieving at 8-10 degrees C and 3-5 degrees C. The changes of isoesterase patterns are similar at the two different temperatures. Over the courses of dormancy relieving, some new bands are detected and some original bands are enhanced. These results show that the physiological basis may be similar over the courses of dormancy relieving at 8-10 degrees C and 3-5 degrees C.

Reperfusion after liver transplantation in rats differentially activates the mitogen-activated protein kinases

The injury resulting from cold ischemia and warm reperfusion during liver transplantation is a major clinical problem that limits graft success. Kupffer cell activation plays a pivotal role in reperfusion injury, and Kupffer cell products, including free radicals and tumor necrosis factor alpha (TNF-alpha), are implicated as damaging agents. However, the second messengers and signaling pathways that are activated by the stress of hepatic ischemia/reperfusion remain unknown. The purpose of this study is to assess the activation of the three known vertebrate mitogen activated protein kinase (MAPKs) and the activating protein 1 (AP-1) transcription factor in response to ischemia and reperfusion in the transplanted rat liver. There was a potent, sustained induction of c-jun N-terminal kinase (JNK), but not of the related MAPKs extracellular signal-regulated kinases (ERK) or p38, upon reperfusion after transplantation. TNF-alpha messenger RNA (mRNA) levels and transcription factors AP-1 and nuclear factor-kappaB (NF-kappaB) were induced in the liver after 60 minutes of reperfusion. Finally, there was an elevation of ceramide, but not diacylglycerol or sphingosine, in the transplanted liver. Ceramide is a second messenger generated by TNF-alpha treatment and is an activator of JNK. Because JNK activation preceded the elevations in ceramide and TNF-alpha mRNA, these results suggest that increased hepatic TNF-alpha and ceramide may perpetuate JNK induction, but that they are not the initiating signals of JNK activation during reperfusion injury in the transplanted liver.

[Electrophoresis assay on isoperoxidase in the course of seed dormancy relieving for Fritillaria thunbergii Miq. at two different low temperatures]

The relieving of seed dormancy for Fritillaria thunbergii required 50 days at 8-10 degrees C and 80 days at 3-5 degrees C. During the relieving process, isoperoxidase pattern changes were studied by means of electrophoresis. The results showed that some new bands were detected, some original bands enhanced as the seeds were treated with a low temperature, and the changes of lsoperoxidase patterns were similar at two different low temperatures.

[Comparative study on the erect and fallen types of Platycodon grandiflorum (Jacq.) DC]

Based on botanica characters, phenophase, yield and content of active constituents, the erect and fallen types of platycodon grandiflorum were compared. The results show that the comprehensive characters of erect type are better than those of fallen type and the erect type is therefore good for popularization. Some specific characters of the fallen type are better than those of the erect type, and the fallen type is therefore to be preserved as one of the germ plasm resources.

Force-frequency response in isoproterenol-induced hypertrophied rat heart

Rate-dependent force production was investigated using small trabecular muscle from control and hypertrophied rat cardiac muscle. Cardiac hypertrophy was induced by daily subcutaneous injection of isoproterenol (0.3 mg/kg body weight) for 12 days. The force-frequency relationship, for the control rat myocardium, is clearly biphasic. A stepped increase in stimulation frequency from 0.1 to 0.5 Hz results in a decrease in contractile force (negative phase). However, at higher stimulation frequency above 0.5 Hz, an increased contractile force is revealed (positive phase). Membrane action potential duration (APD50) was used to reflect sarcolemmal Ca2+ influx. The frequency-dependent increase in APD50 and the ability of nifedipine, a sarcolemmal L-type Ca2+ channel blocker, to eliminate the positive-force frequency response, indicate that sarcolemmal Ca2+ influx is important for force development at high stimulation frequency. Relative Ca2+ content of sarcoplasmic reticulum is estimated from rapid cooling contractures. The parallel change of rapid cooling contractures and twitch force suggests that the sarcoplasmic reticulum Ca2+ content alters with varying frequencies of stimulation. Isoproterenol-induced hypertrophied muscle shows a greater contractile force, increased nifedipine-sensitive force development and prolonged APD50 compared to controls. These data suggest a greater availability of intracellular Ca2+ to activate contraction in hypertrophied muscle, possibly by amplified Ca2+ influx via L-type channel.

[Labour induction in women at term with mifepristone and misoprostol]

OBJECTIVE

To determine the efficacy of mifepristone (RU486) combined with misoprostol as an induction agent for the initiation of labour in women at term.

METHODS

Our study group contained 68 pregnant women at term (gestational age: 38-41 weeks) who had clear clinical indications for labour induction. They received mifepristone either 150 mg or 200 mg respectively in the first two or three days. The shortening of the cervical length, the change of Bishop score and the change of the blood serum in oestradiol (E2) concentration and progesterone (P) concentration were observed respectively before and after medication. On the fourth day, misoprostol was added from 100 micrograms to 300 micrograms successively. The outcome of labour induction in these women was recorded.

RESULTS

The cervical length of women who were given mifepristone was 1-3 cm shorter and Bishop score was 4-5 higher than those before treatment. The E2 concentration and the P concentration were significantly higher and lower respectively than those before treatment. The cervical ripening ratio was 100.00%. The incidence of the onset of labor was 93.00% and the incidence of vaginally delivery was 80.88% after misoproston was given.

CONCLUSION

Mifepristone combined with misoprostol is a safe, efficient, economical and convenient induction agent for initiation of labor in women at term.

Percutaneous balloon mitral valvuloplasty in patients with mitral restenosis after previous surgical commissurotomy. A matched comparative study

BACKGROUND

Although the efficacy of percutaneous balloon mitral valvuloplasty in patients with unoperated mitral stenosis has been well documented, there exists less clear-cut data on its effectiveness in patients with mitral restenosis after previous surgical commissurotomy. Accordingly, the purpose of this study was to evaluate our immediate and midterm results of balloon mitral valvuloplasty in this subset of patients with previous mitral surgery.

METHODS

Between October 1991 and August 1995, 29 consecutive patients with mitral restenosis after prior surgical commissurotomy (group 1) underwent Inoue balloon mitral valvuloplasty. They were matched on a patient-to-patient basis with regard to baseline mitral echocardiographic score mitral valve area, severity of angiographic mitral regurgitation and follow-up duration with 29 other patients with unoperated mitral stenosis (group 2) who underwent balloon mitral valvuloplasty during the same study period.

RESULTS

Balloon mitral valvuloplasty yielded identical improvements in transmitral gradient and mitral valve area (from 0.8 to 1.6 cm2) determined echocardiographically, and similar changes in the severity of mitral regurgitation in both groups of patients. All procedures were successfully completed without major cardiac complications. Follow-up echocardiographic assessment in 73% of patients revealed equal mitral valve area (1.6 cm2) and a restenosis rate of 17%, with no difference in the restenosis rate between the two groups.

CONCLUSION

Balloon mitral valvuloplasty in selected patients with mitral restenosis after past surgical commissurotomy can be performed safely and with similar immediate and midterm efficacy as in patients with de novo mitral stenosis.

Detection of alpha-hydroxyethyl free radical adducts in the pancreas after chronic exposure to alcohol in the rat

Chronic pancreatitis is characterized by inflammation and fibrosis leading to tissue destruction; in industrialized nations, alcohol abuse is the cause of 70-80% of cases of pancreatitis in adults. The purpose of the current work was to determine whether free radical adducts are produced by the pancreas during the early phases of chronic exposure to ethanol. Accordingly, rats were chronically fed ethanol using the model of continuous enteral infusion developed by Tsukamoto et al.[Am. J. Physiol. 247: R595-R599 (1984)]. Histological evaluation revealed only mild acinar steatosis and spotty necrosis after 4 weeks of alcohol treatment; the pancreatic enzymes lipase and amylase were not elevated. Furthermore, no fibrosis was detected, nor were there differences in pancreatic collagen alpha 1(l) mRNA levels between the dietary control and ethanol-treated groups. After 4 weeks, rats were injected with the spin trap alpha-(4-pyridyl-1-oxide)-N-tert-butylnitrone (1 g/kg intravenously), and pancreatic secretions were collected over a 4-hr period. A six-line free radical adduct spectrum indicative of a carboncentered free radical was detected in pancreatic secretions and in Folch extracts of pancreatic tissue by electron spin resonance spectroscopy. Control experiments ruled out ex vivo radical formation. This study represents the first detection of radical adducts in pancreatic secretions. When [13C]ethanol (3 g/kg intragastrically) was administered, a definitive 12-line spectrum was detected in pancreatic secretions, demonstrating that the alpha-hydroxyethyl radical adduct was formed in the pancreas from [13C]ethanol. Interestingly, only a six-line signal was detected in tissue extracts under these conditions. Free radicals, therefore, are formed in the pancreas during the early phases of chronic alcohol intake in rats before the development of overt pathology.

Destruction of Kupffer cells increases survival and reduces graft injury after transplantation of fatty livers from ethanol-treated rats

This study investigated the role of Kupffer cells on survival and graft injury in transplanted fatty livers from rats treated acutely with ethanol. Donor rats were given ethanol (5 g/kg, by mouth) 20 hours before explantation, and liver grafts were preserved in University of Wisconsin cold storage solution for 24 to 42 hours prior to implantation. Blood samples were taken from the inferior vena cava for 3 hours after implantation. During this time, serum aspartate transaminase levels increased gradually from 122 U/L to 597 U/L in control rats, while ethanol treatment elevated values to 2,278 U/L. Gadolinium chloride (20 mg/kg, given intravenously to recipients 24 hours before explantation), a selective inactivator of Kupffer cells, minimized the increase in aspartate transaminase levels significantly. After implantation of grafts cold-stored for 42 hours, survival rates were 88% in control rats but only 33% in ethanol-treated rats. Gadolinium chloride improved survival nearly to control values. Ethanol nearly doubled white blood cell adhesion, an effect also largely blocked by gadolinium chloride. Further, alpha-(4-pyridyl 1-oxid)-N-tert-butylnitrone radical adducts detected in the bile were increased twofold by ethanol treatment. This effect was also reversed by gadolinium chloride. Taken together, these data indicate that survival is poorer and graft injury is greater in fatty livers from ethanol-treated rats. Inactivation of Kupffer cells minimized graft damage, most likely by improving hepatic microcirculation and diminishing lipid peroxidation.

Safety and efficacy of percutaneous Inoue-balloon mitral commissurotomy

BACKGROUND

Although percutaneous transvenous mitral commissurotomy (PTMC) is currently accepted as the first-line treatment modality for selected patients with mitral stenosis, technical failures and the potential risk of inadvertent cardiac perforation with tamponade, resultant severe mitral regurgitation and death associated with the procedure continue to be important issues of concern.

OBJECTIVES

The purpose of this study was to assess the safety profile and acute results of Inoue-balloon PTMC in a consecutive series of 50 patients with symptomatic significant mitral stenosis who underwent the procedure between January 1993 and August 1994.

RESULTS

PTMC was successfully completed in all patients without encountering cardiac perforation, cardioembolism, severe (> or = grade 3+) angiographic mitral regurgitation or death. The mitral valve area increased from 0.8 +/- 0.2 cm2 to 1.7 +/- 0.4 cm2 (p = 0.0001) as assessed echocardiographically. Optimal results defined as a valve area improvement of > or = 50% and/or a final valve area of > or = 1.5 cm2 without significant mitral regurgitation (> or = 2 grade increase in mitral regurgitation or a final regurgitation > or = 3+) was obtained in 94% of patients.

CONCLUSION

We confirm that Inoue-balloon PTMC is a safe and highly effective procedure as reflected by the absence of cardiac perforation, cardioembolism, severe mitral regurgitation or death and the excellent enlargement in mitral valve area. Furthermore, in our study the clinical restenosis rate was low with the majority of patients maintaining their improved functional status over a 14-month follow-up period.

[Effect of escharectomy during burn shock stage on bacterial and endotoxic translocation from the gut]

120 SPF rats (Wistar) were randomly divided into 3 groups (1) simple skin grafting group (Group A). (2) Escharectomy during burn shock group (Group B). (3) Routine escharectomy group (Group C) Full-thickness burn of 30% TBSA was produced in Group B and Group C. One hour after scald intravenous fluid replacement was instituted. First stage escharectomy has been performed 24 hours after burn and 5 days postburn. The results demonstrated that the contents of both plasma LPS and TNF in Group B were significantly lower as compared with these in Group C. Our data indicated escharectomy during burn shock would effectively eliminate the effects of the endotoxemia. Endotoxin play an important role in the bacterial and endotoxic translocation.

Immediate and long-term results of percutaneous Inoue balloon mitral commissurotomy with use of a simple height-derived balloon sizing method for the stepwise dilation technique

OBJECTIVE

To assess the short- and long-term efficacy of Inoue balloon percutaneous transvenous mitral commissurotomy (PTMC) with use of our simple balloon sizing method based on patient height.

DESIGN

Data from 105 consecutive patients with symptomatic mitral stenosis who underwent 107 PTMC procedures between October 1991 and April 1995 at our hospital were analyzed.

RESULTS

All PTMC procedures were successfully completed with no instances of cardiac perforation, systemic embolism, severe mitral regurgitation (grade 3 or more angiographically), or death. The mean mitral valve area increased from 0.8 +/- 0.2 cm2 to 1.7 +/- 0.4 cm2 (P = 0.0001), as assessed echocardiographically. Optimal results -- defined as an improvement in valve area of 50% or more or a final valve area of 1.5 cm2 or more without significant mitral regurgitation (an increase in mitral regurgitation of two or more grades or a final regurgitation of grade 3 or more) -- were obtained in 96% of patients. At a mean follow-up interval of 20 months, symptomatic benefit was maintained in 97% of patients. Echocardiographic evidence of restenosis (loss of more than 50% initial gain in valve area, a valve area of less than 1.5 cm2, or both) was noted in 9.8%.

CONCLUSION

Inoue balloon PTMC with use of our simple balloon sizing method yielded excellent short- and long-term results in terms of mitral valve enlargement and sustained symptomatic benefit without the creation of severe mitral regurgitation.