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Biomedical subjects

J Mei

Publications and source records attributed to J Mei.

At least 73 records · Page 4Linked to original sources
PubMed1993

Percutaneous balloon mitral valvuloplasty for mitral stenosis with and without associated aortic regurgitation.

Between November 1985 and December 1991, percutaneous balloon mitral valvuloplasty (PBMV) with the Inoue balloon catheter (Toray Marketing & Sales [America], Inc., New York, N.Y.) was performed in 53 patients with rheumatic mitral stenosis and associated mild to moderate aortic regurgitation. Mean left atrial pressure was 22.5 +/- 8.6 mm Hg and 9.7 +/- 5.5 mm Hg before and after PBMV, respectively (p < 0.001). The mean diastolic mitral gradient as determined by the catheter method decreased from 18.7 +/- 11.4 mm Hg to 2.1 +/- 3.1 mm Hg (p < 0.001). The echocardiographic mitral valve area was 1.0 +/- 0.2 cm2, 2.0 +/- 0.6 cm2, and 1.9 +/- 0.5 cm2, before and after PBMV and at follow-up (p < 0.001 before PBMV vs after PBMV and at follow-up). The mean diastolic mitral gradient as determined by two-dimensional and Doppler echocardiography was 19.3 +/- 8.4 mm Hg, 5.2 +/- 4.1 mm Hg, and 6.6 +/- 3.3 mm Hg, before and after PBMV and at follow-up, respectively (p < 0.001). The phonocardiographic interval between the Q wave and the mitral component of the first heart sound was 85.2 +/- 15.2 msec, 74.2 +/- 13.4 msec, and 72.3 +/- 15.7 msec before and after PBMV and at follow-up (p < 0.001 before PBMV vs after PBMV and at follow-up). The phonocardiographic interval between the aortic second sound and opening snap was 73.4 +/- 18.1 msec, 88.7 +/- 9.6 msec, and 92.1 +/- 11.7 msec before and after PBMV and at follow-up (p < 0.001 before PBMV vs after PBMV and at follow-up). The voltage of P loop in the frontal plane of the vectorcardiogram was 0.25 +/- 0.04 mV, 0.21 +/- 0.04 mV, and 0.20 +/- 0.03 mV before and after PBMV and at follow-up (p < 0.001 before PBMV vs after PBMV and at follow-up). The New York Heart Association classification improved from class II in 26 patients and class III in 27 patients before PBMV to class I in 48 patients and class II in five patients after PBMV. These hemodynamic, noninvasive, and clinical results were not significantly different from those that were obtained in 112 patients with mitral stenosis without associated aortic regurgitation, who were studied during the same period in our cardiac catheterization laboratory. It was concluded that patients with rheumatic mitral stenosis are suitable candidates for PBMV whether or not they have associated aortic regurgitation of mild to moderate degree.

Adolescent↗
PubMed1993

Enterostatin: a gut-brain peptide regulating fat intake in rat.

The effect of enterostatin on high-fat food intake has been investigated. After 18 h of food deprivation, rats were injected intravenously with enterostatin (VPGPR). A dose of 38 nmol of enterostatin gave a significant inhibition of high-fat food intake, while at a higher dose of 76 nmol the inhibiting effect was lost. During the first hour, after injection of enterostatin, there was even a slight increase in food intake. Binding studies of tritiated enterostatin to crude brain membranes indicated one binding site with high affinity (Kd = 0.5 nM) and one with low affinity (Kd = 170 nM). The two dissociation constants suggest different receptor subtypes and could explain why enterostatin both can inhibit and, at high doses, stimulate fat intake in rats.

Animals↗
PubMed1993

Identification of enterostatin, the pancreatic procolipase activation peptide in the intestine of rat: effect of CCK-8 and high-fat feeding.

Enterostatin, the procolipase activation peptide, has been suggested in previous studies to act as a satiety signal for food intake, with a specificity for fat intake. In this study, by use of a competitive enzyme-linked immunosorbent assay with a detection limit of 4.115 nmol/L and within 6% intra- and interassay variation, the immunoreactive and chromatographic characterization of enterostatin in intestinal content was undertaken in Sprague-Dawley rats. Following intravenous infusion of cholecystokinin octapeptide (CCK-8; 200 pmol/kg/h) for 60 min, the concentration of intestinal enterostatin increased from a basal level of 2.0 +/- 0.7 microM to 5.64 +/- 1.1 microM at time point 60 min. The enterostatin level remained at 4.24 +/- 0.54 microM for 120 min after the CCK infusion had ceased. Pancreatic lipase and colipase activities in rat intestinal content also increased during the CCK-8 infusion. The enzyme activities reached the maximal level after 30 min of CCK infusion and thereafter progressively decreased to basal levels, remaining there during the following 2 h. The basal level of intestinal enterostatin in rats fed with standard pellets was found to be increased from 1.42 +/- 0.14 to 3.86 +/- 0.4, 3.17 +/- 0.54, and 5.02 +/- 1.6 microM on days 1, 3, and 7, respectively, after high-fat feeding. Parallel to the increase in intestinal enterostatin, there was a significant increase in pancreatic lipase and colipase activities in the intestine during the ingestion period of high-fat diet as compared with the control group. The estimated molecular mass of enterostatin immunoreactivity of intestinal content was similar to that of the synthetic pentapeptide. These results suggest that immunoreactive enterostatin (Val-Pro-Gly-Pro-Arg) is normally present in rat intestinal content, is significantly increased after stimulation with CCK-8, and is also increased after prolonged high-fat feeding.

Amino Acid Sequence↗
PubMed1993

Enterostatin--its ability to inhibit insulin secretion and to decrease high-fat food intake.

Enterostatin is a peptide which has been found to decrease food intake with a specificity for the fat contained in the food. In this work we have investigated the effect of enterostatin (Val-Pro-Asp-Pro-Arg) and its proteolytic fragments, des-arg-enterostatin (Val-Pro-Asp-Pro) and the tripeptide Asp-Pro-Arg, on insulin secretion. It was found that enterostatin and desarg-enterostatin inhibited insulin secretion from isolated rat islets by 55.3% (P < 0.05) and 53.6% (P < 0.05) at 1.6 x 10(-4) M concentration, while the tripeptide Asp-Pro-Arg at 1.6 x 10(-4) M concentration had no significant effect and increased insulin secretion by 33.0%. Enterostatin at 200 ng after intraventricular administration was found to inhibit the intake of a high-fat diet by 45.0%, while des-arg-enterostatin (200 ng) had no effect, in agreement with previous findings. The tripeptide Asp-Pro-Arg (200 ng) had no effect on the intake of a high-fat diet compared to saline injection. The ability of enterostatin to inhibit high-fat food intake and decrease insulin secretion may be important for the prevention of obesity and type II diabetes, conditions linked through hyperinsulinemia.

Amino Acid Sequence↗
PubMed1993

[An investigation on smoking situation among middle school students in Japan and in Jiangxi, China].

The past smoking rate among middle school students in Jiangxi was 30.5%, which was higher than that in Japan (25.4%). However, the present smoking rate and the frequent smoking rate among middle school students in Jiangxi are 5.8% and 1.1%, respectively, which are far lower than those in Japan (8.7% and 5.3%). The past smoking rate among boy students at each academic year in Jiangxi was higher than that in Japan, but the statistical indices of the present smoking rate and of the frequent smoking rate among boy students and among girl students at each academic year are lower than those in Japan. In Japan, the smoking rate among middle school students in cities was higher than that in the countryside, but vice versa in Jiangxi. The average number of cigarettes consumed per day in Japan was higher than that in Jiangxi. This investigation indicates that the smoking rate among middle school students was much influenced by their friends and relatives, health education in schools, self-feelings about school life and attitude towards smoking, etc.

Adolescent↗
PubMed1992

Long-term results of percutaneous mitral valvuloplasty with the Inoue balloon catheter.

The initial 85 patients who successfully underwent percutaneous mitral valvuloplasty (PMV) with the Inoue balloon catheter at the Guangdong Cardiovascular Institute between November 1985 and November 1988 had a mean follow-up period of 5 +/- 1 year (range 43 to 79 months). Before and after PMV and at follow-up, mean diastolic mitral gradients by the catheter method were 17.5 +/- 6.2, 3.1 +/- 3.3 and 3.3 +/- 3.4 mm Hg, respectively (p < 0.001 before vs after PMV and before vs follow-up; and p > 0.05 after PMV vs follow-up). Mean diastolic mitral gradients by the Doppler method were 18 +/- 6, 8 +/- 5 and 9 +/- 5 mm Hg, respectively (p < 0.001 before vs after PMV and before vs follow-up; and p > 0.05 after PMV vs follow-up). Mean diastolic mitral gradients by the Doppler method were 18 +/- 6, 8 +/- 5 and 9 +/- 5 mm Hg, respectively (p < 0.001 before vs after PMV and before vs follow-up; and p > 0.05 after PMV vs follow-up). Mitral valve areas by the echo-Doppler method were 1.1 +/- 0.3, 2.0 +/- 0.4 and 1.8 +/- 0.5 cm2, respectively (p < 0.001 before vs after PMV and before vs follow-up; and p > 0.05 after PMV vs follow-up). Phonocardiographic and vectorcardiographic studies, and cardiopulmonary exercise testing showed significant improvement after PMV and at follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Effect of enterostatin given intravenously and intracerebroventricularly on high-fat feeding in rats.

The effect of enterostatin, the amino-terminal pentapeptide of pancreatic procolipase, on high-fat food intake has been investigated after intracerebroventricular as well as after intravenous injection. After an overnight fast enterostatin given i.c.v. at doses of 167 pmol and 333 pmol produced a significant and dose-dependent reduction in high-fat food intake, while a higher dose of 667 pmol had no effect. Following intravenous injection of enterostatin the intake of high-fat food was suppressed at doses of 8.3 nmol and 16.7 nmol, while no effect was observed at higher doses. The inhibition of feeding started 3 h after the initiation of feeding and persisted to the end of the test period (6 h). Enterostatin at a dose of 16.7 nmol gave no sign of aversion in an aversion test comparing the effect of enterostatin, lithium chloride and saline on liquid intake. The data suggest that enterostatin may exert its satiety effect on high-fat feeding by being absorbed into the bloodstream.

Animals↗
PubMed1992

Differential inhibition of fat intake in two strains of rat by the peptide enterostatin.

The effect of enterostatin, the amino-terminal pentapeptide of pancreatic procolipase, on food intake was investigated in two strains of rat, the dietary fat-sensitive Osborne-Mendel (OM) rat and the dietary fat-resistant S5B/Pl rat. After an overnight fast, enterostatin inhibited intake of high-fat (HF) but not low-fat (LF) diets in OM rats, but had no effect in S5B/Pl rats. When fed a macronutrient three-choice diet, OM rats selected fat preferentially, whereas S5B/Pl rats selected carbohydrate. Enterostatin specifically inhibited the intake of fat in OM rats but not S5B/Pl rats fed a three-choice macronutrient diet. The activity of pancreatic colipase was increased in S5B/Pl rats on both HF and LF diets compared with OM rats. Pancreatic colipase activities were negatively related to the voluntary intake of fat on three-choice macronutrient diets. The data support the hypothesis that enterostatin may control the intake of dietary fat.

Animals↗
PubMed1992

[Inhibition of dopamine on WDR neurons of dorsal horn not antagonized by phentolamine and naloxone in rats].

The inhibitory effects of dopamine (DA) applied spinally on the wide dynamic range (WDR) neurons of dorsal horn in rats were studied with extracellular recording technique. 54 WDR units were tested from 43 rats. With a dosage of DA from 0.26 x 10(-6) to 1.58 x 10(-6) mol/kg, the inhibitory effect of the neurotransmitter on the responses of dorsal horn neurons to noxious transcutaneous electrical stimulation exhibited a gradual increase. After DA (0.52 x 10(-6) mol/kg) administration, the inhibitory effect of DA began to appear in 5 min and reach to maximum in 15 min, whereupon the maximum level could be maintained for about 25 min. This effect of DA could be reversed completely by dopaminergic receptor antagonist, droperidol (0.66 x 10(-6) mol/kg) but not by 2.65 x 10(-6) mol/kg phentolamine or 1.37 x 10(-6) mol/kg naloxone. The results of the present investigation suggest that DA may be involved in the modulation of nociception at the spinal level as an independent neurotransmitter.

Animals↗
PubMed1991

Pancreatic procolipase propeptide, enterostatin, specifically inhibits fat intake.

Pancreatic procolipase is activated by trypsin forming colipase, a cofactor for pancreatic lipase involved in intestinal fat digestion and a pentapeptide named enterostatin. Enterostatin with the sequence Val-Pro-Asp-Pro-Arg (VPDPR) was previously shown to decrease food intake in rats both after peripheral and central injection. In this work enterostatin has been shown to reduce specifically the consumption of a high-fat diet as opposed to a low-fat diet after central injection of Sprague-Dawley rats. After starvation for 18 hours the rats were given a free choice of a low-fat diet (5.2% fat by weight; 14.1% by energy) and a high-fat diet (17.8% fat by weight; 32.8% by energy) in separate containers. After injection of 200 ng of VPDPR into the lateral ventricle, the rats selectively decreased the intake of the high-fat diet by 45% (p less than 0.005), while the intake of the low-fat diet was unaffected compared to saline injection. VPDP after intracerebroventricular injection had totally lost the selective effect on the consumption of a high- fat and a low-fat diet. It is suggested that enterostatin formed during fat digestion from pancreatic procolipase may provide a feed-back signal for the intake of lipid.

Animals↗
PubMed1990

Percutaneous mitral valvuloplasty with a single rubber-nylon balloon (Inoue balloon): long-term results in 71 patients.

The first 71 patients with rheumatic mitral stenosis who successfully underwent single rubber-nylon balloon (Inoue balloon) percutaneous mitral valvuloplasty (PMV) from November 1985 to August 1988 had a mean follow-up period of 27.1 +/- 11.6 months (range, 14 to 48 months). Functional status before PMV was New York Heart Association (NYHA) functional class IV in two, class III in 38, and class II in 31. Pre and post PMV and follow-up mean diastolic mitral gradient by catheter method was 17.5 +/- 6.9, 2.7 +/- 3.5, and 3.3 +/- 3.4 mm Hg (p less than 0.001 pre versus post PMV and pre PMV versus follow-up; and p greater than 0.005 post PMV versus follow-up). By Doppler method the mean diastolic gradient was 17.4 +/- 5.5, 8.5 +/- 4.7, and 9.2 +/- 4.1 mm Hg, respectively (p less than 0.001 pre versus post PMV and pre PMV versus follow-up; and p greater than 0.05 post PMV versus follow-up). Mitral valve area was 1.12 +/- 0.26, 2.04 +/- 0.41, and 1.92 +/- 0.45 cm2, respectively (p greater than 0.001 pre versus post PMV and pre PMV versus follow-up; and p less than 0.05 post PMV versus follow-up). The phonocardiographic and vectorcardiographic studies and cardiopulmonary exercise testing showed significant improvement after PMV and at follow-up. At follow-up the NYHA functional class was 1 in 57 patients, class II in 13, and class III in one patient with severe mitral valve calcification and subvalvular fusion, in whom restenosis occurred 18 months after PMV.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗