[Effects of estrone on transmission at neuromuscular junction of the toad]

The effects of estrone on neuromuscular transmission were studied intracellularly at the muscle fiber endplate in isolated sciatic nerve-sartorius muscle preparations of the toad (Bufo bufo gargarizans) in vitro. The results showed that estrone (10(-4) mol/L), added to bath medium, caused an increase in amplitudes of endplate potentials (EPP) both in 10 micrograms tubocurarine treated and 10 mmol/L MgCl2 treated preparations, but the increase was more prominent in the former, and that estrone, 30 min after being added to bath medium, caused clear increase both in frequency and amplitude of miniature endplate potentials (MEPP), but the wave form of MEPP remained unchanged and the resting membrane potentials were also unchanged. These results suggest that estrone can increase neuromuscular transmission, which seems to involve primarily the presynaptic mechanism.

[Divergence of VP7 gene and VP4 gene variable regions of G1 rotaviruses isolated from different geographic locations around the world]

Group A rotaviruses are the most important etiologic agents of severe gastroenteritis in children, and as a result, the development of an effective vaccine against severe rotavirus diarrhea is a top public health priority. Previous studies indicated that G1 rotavirus are much more common in most countries around the world and development of G1--specific vaccine may be important in protection against human illness. In this report, we analyzed the VP7 gene and VP4 gene variable regions of 36 G1 rotavirus community strains collected from different geographic locations worldwide. Comparative analysis of the VP7 sequences showed that most of the amino acid substitutions of global strains occurred in and around previously identified epitope regions VR3, VR4, and VR6, suggesting that there are slight antigenic differences among these strains. Growtree phylogram using the VP7 amino acid sequences as an index grouped all strains into three clusters. The VP7 sequence of each cluster possesses distinctive amino acid residues which are peculiar to most members of the same group at a most positions. These data will be essential to achieve a much better understanding of molecular epidemiologic characteristics of G1 rotavirus around the world.

[Characterization of volatile organic compounds from indoor materials]

Volatile organic compounds emitted from eight indoor materials including paint, wallpaper glue, maticolor coat, floorwax floor covering and air freshener and were analyzed by headspace GC-FID and GC-MS. About 3-30 organic compounds were detected from each material. It was shown that the emitted compounds and emission rate from different materials were different. The emitted compounds included paraffin, olefine, alcohol, aldehyde, ether, ester and aromatic compounds. The results of dynamic experiments in test chamber showed that the chamber concentration of volatile organic compounds from paint vs. time data follows a double exponent equation.

[Chemical constituents of the roots of Bupleurum longicaule Wall. ex DC. var. franchetii de Boiss and B. chaishoui Shan et Sheh]

From the roots of Bupleurum longicaule var. franchetii, B. chaishoui and the official species B. chinense, ten saikosaponins have been isolated and identified as saikosaponin a, saikosaponin d, saikosaponin c, saikosaponin e, saikosaponin b2, 2"-O-acetylsaikosaponin a, 3"-O-acetylsaikosaponin a, 3"-O-acetylsaikosaponin d, 6"-O-acetylsaikosaponin a and 6"-O-acetylsaikosaponin d respectively. It has been shown that the chemical constituents of these three Bupleurum plants are very similar, therefore, the medicinal value of B. longicaule var. franchetii and B. chaishoui is further verified.

[A preliminary study on the hormonal causes of seasonal change in miniature endplate potentials at the neuromuscular junctions of the toad]

The hormonal causes of seasonal change in amplitudes of miniature endplate potentials (MEPP) in the adult toad (Bufo bufo gargarizans) were studied with intracellular recordings of MEPP at the neuromuscular junction of sartorius muscle fiber in vitro by adding L-thyroxine sodium and estrone to the bath medium during spring and autumn respectively. The results showed that L-thyroxine sodium (50 mumol/ L) could not change the amplitude of MEPP, regardless of spring or autumn, but estrone (100 mumol/L) could cause a clear increase in MEPP amplitude in both seasons. From these results it was presumed that thyroxine might be less related to the seasonal changes in MEPP amplitude whereas the seasonal fluctuations of gonadal hormones in the body might play a role.

[Inhibitory effect of substance P of caudate nucleus on gastric motility via substantia nigra and dorsal vagal nucleus mediated by vagus nerve]

Effects of lesion of bilateral hypothalamus (LH), substantia nigra and dorsal vagal nucleus as well as their efferent pathway on the inhibition of gastric myoelectric fast wave and gastric motility due to injection of substance P (SP) to caudate nucleus were studied in rats. The experimental results showed that this induced inhibition was independent of the presence of intact LH but abolished by lesioning substantia nigra, dorsal vagal nucleus or vagus nerve. Depletion of sympathetic transmitter by reserpine did not affect the occurrence of the inhibition. Thus, it appears that the gastric inhibitory effect of caudate nucleus SP is mediated via substantia nigra and dorsal vagal nucleus to vagus nerve.

[Seasonal variation and circannual rhythm of miniature end-plate potentials recorded from the neuromuscular junctions of the adult toad (Bufo bufo gargarizans)]

The seasonal variations and circannual rhythm of miniature end-plate potentials (MEPP) recorded from the sartorius neuromuscular junctions (NMJ) of 66 female and 62 male adult toads (Bufo bufo gargarizans) were studied with intracellular microelectrode recording techniques of electrophysiology. The results revealed that the mean amplitude of MEPP in each month of a year showed clear seasonal variation with a nadir in September and October and a zenith in March and April. This seasonal variation in MEPP amplitude was proved to be a circannual rhythm by single cosinor analysis and zero amplitude test, and the three parameters of the rhythm, i.e. mesor, amplitude and acrophase were 0.29 +/- 0.05 mV, 0.25 mV and -97.17 degrees in female toad and 0.19 +/- 0.02 mV, 0.16 mV and -92.01 degrees in male toad, respectively; the circannual rhythm in female toad was more distinct than that in male. Neither seasonal variation nor circannual rhythm was statistically significant in the changes of frequency of MEPP, regardless of toad sexuality.

[Orthotopic heart transplantation: a case report]

In July 1994, we performed orthotopic heart transplantation for a patient with hypertrophic myocardiopathy, who had had open heart surgery enlarging the right ventricular outlet. The patient had an excellent postoperative result. He received triple-drug immunosuppressive therapy. Large dose of methyl-prednisolone was used successfully for his acute rejection reaction. At present, the patient is living well with good cardiac, hepatic and renal function. We described donor heart harvest, myocardial protection, operative procedure, immune monitoring, anti-rejection and anti-infectious therapy. We introduced the process of protecting donor heart on the way to hospital by retrograde perfusion with medium hypothermic oxygenated-blood combined with St. Thomas cardioplegia. Besides endomyocardial biopsy, other noninvasive examinations such as noninvasive cardiac output monitoring could be helpful to monitor acute rejection reaction.

[Participation of dopamine on the muscarinergic inhibitory effect of substance P on gastric myoelectric activity and motility]

Our previous study showed that microinjection of substance P (SP) into caudate nucleus inhibits gastric myoelectric fast wave and gastric motility, an effect mediated by muscarinic receptor. The present investigation showed that this effects of SP could be blocked by coinjected SP antiserum or SP antagonist [Arg6, D-Trip7,9, MePhe8]-SP6-11 or D2 dopamine antagonist haloperidol. In addition, microinjection of dopamine (DA) into caudate nucleus could also inhibit gastric fast wave and motility, an effect again being blockable by coinjected DA antagonist haloperidol or atropine. Thus, it appears that the muscarinergic inhibitory effect of SP on gastric fast wave and motility is mediated by D2 dopamine receptor.

[Studies on inhibitive effects of organic selenium on cell damage caused by SiO2]

Changes in potassium content of macrophage in guinea pigs and in membrane protein of erythrocytes in rats caused by quartz dust, and the effects of selenium-protein and selenium-containing polysaccharide of cell membrane on them were determined with atomic absorption spectrometry and electronic spin label. Results showed quartz could significantly decrease potassium content of macrophage with a dose-effect relationship. Potassium content in the exposed group could return to normal level as the control group by adding Se-protein into quartz dust. Rotational correlation times of the membrane protein in erythrocytes could be decreased by quartz dust, and Se-protein and Se-containing polysaccharide could make them normal. It suggested quartz could cause cell permeability significantly increased, cleavage of peptide-chain of membrane protein, degradation and cross-linkage of protein, and cell damage, but organic selenium could decrease cytotoxicity caused by quartz dust and protect cells from the damage.

Physical activity and cardiovascular risk factors in rural Shanghai, China

BACKGROUND

Data on the association between physical activity and cardiovascular risk factors among populations with a relatively high level of physical activity such as the Chinese, are sparse.

METHODS

In 1991, as part of the Sino-Shanghai Cardiovascular Disease Registry Project, a cross-sectional survey was performed in a random sample of 1206 residents, aged 35-64 years, living in rural Shanghai, China. Information on physical activity was obtained by questionnaire. The level of physical activity was categorized into low, moderate and high, based on the presence of a weekly frequency (< 1, 1-2, > or = 3) of periods of 20 minutes that cause shortness of breath, increase in pulse rate and perspiration. Body mass index (BMI), systolic (SBP) and diastolic blood pressure (DBP) level, serum lipids levels, smoking status and heart rate were assessed.

RESULTS

Across groups with low, moderate and high levels of physical activity, significant inverse trends were found for hypertension, total cholesterol, BMI and heart rate in men, and for hypertension, SBP and DBP, BMI and heart rate in women. High density lipoprotein cholesterol and current smoking were not related to physical activity. When differences in BMI were allowed for, the association between physical activity and hypertension and serum cholesterol in men, and with hypertension, SBP and DBP in women, were attenuated.

CONCLUSIONS

Our findings from a population-based survey in China suggest that a high level of physical activity is associated with favourable levels of some of the established cardiovascular risk factors in men and women.

[Inhibition of gastric myoelectric activity and gastric motility induced by microinjection of substance P into caudate nucleus in mouse]

Changes of gastric myoelectric fast wave, slow wave and gastric motility were studied after microinjection of substance P or ACh into caudate nucleus in an attempt to find the interaction between the two substances. Gastric myoelectric activity and motility were recorded by a RM-6200 four channel recorder and then delivered to a IBM-PC computer for analysis. After microinjection of SP or ACh into caudate nucleus, the gastric myoelectric fast wave and gastric motility were significantly suppressed, while the slow wave was not significantly changed.

The second dorsal metacarpal flap with vascular pedicle composed of the second dorsal metacarpal artery and the dorsal carpal branch of radial artery

A pedicle second dorsal metacarpal flap, comprising the second dorsal metacarpal artery, the partial carpal arterial arch of the dorsal hand, and the dorsal carpal branch of radial artery, was designed. The flap may be rotated through two axes of rotation, one at the entry of carpal branch of radial artery into the first dorsal interosseous muscle and one at the entry of the recurrent cutaneous branch arising from the second dorsal metacarpal artery into the skin. The method introduced can increase as much as possible the length of the vascular pedicle of the second dorsal metacarpal flap. Thus, it can cover a small defect at a more distant area. If the width of this flap is not more than 3 cm, the donor site can be closed directly. The flap had been used in five cases with no necrosis of the flap or complication of the donor site. In further investigation of the postoperative patients, no stiffness and tightness have been observed through a short period of rehabilitation of the hand. The results are satisfactory. The anatomy, the operative technique, and three selective cases are described here.

Free medial gastrocnemius myocutaneous flap transfer with neurovascular anastomosis to treat Volkmann's contracture of the forearm

Some articles have reported the use of medial gastrocnemius transfer to repair soft-tissue defects caused by trauma and inflammation (Morris, 1978; Feldman et al., 1978; Arnold and Mixter, 1983). However, we have not found any report describing the use of free medial gastrocnemius myocutaneous flap transfer with neurovascular anastomosis to treat Volkmann's contracture of the forearm. Since 1982, 20 cases of Volkmann's contracture of the forearm have been treated by transfer of medial gastrocnemius flap with neurovascular anastomosis. These 20 patients ranged in age from 6-18 years, with a mean of 10 years. There were 18 males and 2 females. All cases resulted from ischaemia of the extrinsic and intrinsic muscles of the forearm and hand. The most common causes were severe supracondylar fractures or, less frequently, fracture-dislocations of the elbow. Six to twenty months after operation, the transplanted muscles exhibited normal electromyographic potentials, good volume and contractile power with satisfactory functional recovery of the forearms. The deformities of the hand and wrist were also corrected. In this paper we describe the anatomy of the donor site and the operative procedure.