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Biomedical subjects

J J Wei

Publications and source records attributed to J J Wei.

16 recordsLinked to original sources
PubMed2002

Onset of Asian desertification by 22 Myr ago inferred from loess deposits in China.

The initial desertification in the Asian interior is thought to be one of the most prominent climate changes in the Northern Hemisphere during the Cenozoic era. But the dating of this transition is uncertain, partly because desert sediments are usually scattered, discontinuous and difficult to date. Here we report nearly continuous aeolian deposits covering the interval from 22 to 6.2 million years ago, on the basis of palaeomagnetic measurements and fossil evidence. A total of 231 visually definable aeolian layers occur as brownish loesses interbedded with reddish soils. This new evidence indicates that large source areas of aeolian dust and energetic winter monsoon winds to transport the material must have existed in the interior of Asia by the early Miocene epoch, at least 14 million years earlier than previously thought. Regional tectonic changes and ongoing global cooling are probable causes of these changes in aridity and circulation in Asia.

Journal Article↗
PubMed2001

ECG data compression using truncated singular value decomposition.

The method of truncated singular value decomposition (SVD) is proposed for electrocardiogram (ECG) data compression. The signal decomposition capability of SVD is exploited to extract the significant feature components of the ECG by decomposing the ECG into a set of basic patterns with associated scaling factors. The signal informations are mostly concentrated within a certain number of singular values with related singular vectors due to the strong interbeat correlation among ECG cycles. Therefore, only the relevant parts of the singular triplets need to be retained as the compressed data for retrieving the original signals. The insignificant overhead can be truncated to eliminate the redundancy of ECG data compression. The Massachusetts Institute of Technology-Beth Israel Hospital arrhythmia database was applied to evaluate the compression performance and recoverability in the retrieved ECG signals. The approximate achievement was presented with an average data rate of 143.2 b/s with a relatively low reconstructed error. These results showed that truncated SVD method can provide an efficient coding with high-compression ratios. The computational efficiency of the SVD method in comparing with other techniques demonstrated the method as an effective technique for ECG data storage or signals transmission. Index Terms-Data compression, electrocardiogram, feature extraction, quasi-periodic signal, singular value decomposition.

Algorithms↗
PubMed1995

[Influence of the 2nd and 3rd grade abstracts from scorpion venom of Buthus martensii Karsch on action potentials of fast response myocardiocytes].

AIM: To screen the active components of sodium channel blockade action from Buthus martensii Karsch (BMK) scorpion venom. METHODS: Myocardiocytes of mice were cultured. Action potentials of fast response myocardiocytes were recorded. The effects of 22 contents of BMK scorpion venom in a concentration of 3 mg.L-1 were tested and compared with that of TTX 2.5 mg.L-1, nimodipine (Nim) 3 mg.L-1 and BaCl2 24.4 mg.L-1. RESULTS: BMK-1 and other 19 contents significantly decreased depolarization parameters Vmax, APA, OS, and MDP, which was similar to that of TTX and different from that of Nim and BaCl2. CONCLUSION: The variations in the action potentials of fast response myocardiolcytes indicated that 20 contents of BMK scorpion venom had sodium channel blockade action.

Action Potentials↗
PubMed1994

cDNA approaches to isolation of the mouse mutant weaver gene.

The mouse autosomal recessive mutant gene weaver (wv) results in abnormalities in cerebellum, substantia nigra and testis. Although a substracted cDNA library prepared by removing P31 (wv/wv) sequences from a P1 (wv/+) library should contain mainly nonrepetitive neonatal sequences, unfortunately, repetitive sequences still appear during screening. Two clones, one repetitive, the other not, are used to illustrate the problems encountered in attempting to isolate the weaver gene from a substrated cDNA library.

Amino Acid Sequence↗
PubMed1994

Experimental study on pulmonary injury related to oxygen-derived free radicals in acute necrotizing pancreatitis in dogs.

It is postulated the pulmonary injury in acute necrotizing pancreatitis could be due to oxygen-derived free radicals released during the attack of acute pancreatitis. To elucidate the relationship between oxygen-derived free-radicals and the degree of pulmonary injury in acute necrotizing pancreatitis, lipid peroxide (LPO) in lung tissues, bronchoalveolar lavage fluid and serum were measured in 10 adult Mongrel dogs with acute necrotizing pancreatitis induced by injection of 5% sodium taurocholate into the pancreatic duct. Compared with the controls (n = 10), the weight of lung was increased (241.2 +/- 33.7 g vs 121.2 +/- 51.4 g, P < 0.05). LPO of bronchoalveolar lavage fluid (BALF) was higher (3.56 +/- 1.64 mumol/L vs 0.75 +/- 0.31 mumol/L, P < 0.05), LPO in peripheral and portal vein 10 hours after induction of acute pancreatitis was also significantly increased. The LPO content of lung tissue was not higher than that of the control group, but hemorrhage within alveolar space and infiltration by polymorphonuclear and phagocytic cells was seen on histological examination. In conclusion, lipid peroxidation could be an important cause of pulmonary injury in acute necrotising pancreatitis.

Acute Disease↗
PubMed1993

[Sodium channel blocking effect of scorpion venom on cultured mouse myocardiocytes].

Myocardiocytes of mice were cultured. Action potentials were recorded with microelectrodes inside the cells. Scorpion venom from Buthus martensii Karsch 3.75 or 7.5 micrograms.ml-1 decreased the duration of action potential and all of the depolarization concerned parameters of myocardiocytes. The Vmax, TP, APA behaved apparently in a dosage-dependent way. Restoration happened after washing out. Tetrodotoxin 2.5 micrograms.ml-1 acted in a similar way. Nimodipine 3.0 micrograms.ml-1 led to a decrease in action potential duration. BaCl2 0.1 mmol.L-1 elongated the action potential duration, while decreased the parameters concerned with depolarization. These results indicate that the scorpion venom has Na+ channel blocking action.

Action Potentials↗
PubMed1991

[Screening and isolation of the cerebellar specific expressed mRNA in mouse: subtractive hybridization by phenol emulsion reassociation technique].

There are extremely complicated and numerous gene expressions in mammalian brains. Each region of the brain contains a set of mRNA expressed only in that region and these mRNA would be related to presumed region of specific function. Genes preferentially expressed in cerebellum (CB) are therefore the reasonable candioate genes for site of genetic lesions in CB neurodegenerative disorders. In this study, the subtractive hybridization was introduced into screening and isolating CB specific mRNA. Testing CB and front cortex (CTX) cDNA libraries were built, which covered most low abundantly expressed mRNA. By applying over 100 fold excessive CTX and liver single strand cDNA to the CB double strand cDNA, subtractive hybridization was carried out by phenol-emulsion-reassociation-technique (PERT), in which the common expressed housekeep genes would be eluted by restrict site ligation, and CB specific cDNA flanking with EcoRI site in both ds cDNA ends could be cloned into lamda gill phage. PERT subtraction reduced CB cDNA libraries from initial 5.15 x 10(6) to remaining 2.5 x 10(3) recombinants, which were most likely CB specific expressed cDNA. Random Twenty recombinants (over 2 kb inserts) were amplified randomly by polymerase chain reaction (PCR) and were hybridized with CB cDNA and liver cDNA probes in dot blot. 14 inserts positively hybridized with CB cDNA probe and only 3 inserts showed signals with liver cDNA probe. Colony blot presented similar results. 10 cDNA clones which affinited to CB cDNA probe were selected for the Northern blot. In five tissures, 2 cDNA clones binded only in CB mRNA channel, 6 were proved preferential expression in CB and low abundant expression in 4 other tissues, 1 clone was a housekeep gene and 1 could not be detected in all tissues. The partially sequencing of clone PC7 and PD8 were introduced into Computer Gene Bank Data Base. No homologous complements were found between these two clones and over ten thousands genes that have been sequenced. The two clones were newly reported. According to our experiment, we believe that: 1) CB specifically expressed mRNAs are much less than expected comparing with other brain regions; 2) most of CB mRNA expressions are in a preferential way other than unique expression.

Animals↗
PubMed1991

[Purification and identification of red ginseng polypeptides].

Two new polypeptides named RGPI and RGPII were isolated from the Chinese drug red ginseng for the first time. They were identified as propadecopeptide and pentadecopeptidex on the basis of analysis of amino acid composition and determination of molecular weight. Further-more, the effects of RGPs on the content of polysaccharides and the activity of succinodehydrogenase in the 2BS cells of the lung of human embryo were studied.

Amino Acids↗
PubMed1990

Omental autotransplantation in treatment of thromboangiitis obliterans.

From 1981 to 1985, omental autotransplantation was performed for 28 patients with thromboangiitis obliterans on the left lower extremities in 16 patients, the right ones 11, and the right upper limb 1. The early results in all patients were satisfactory. In 19 patients followed up from 1 to 4 years, the results were encouraging, with the improvement of symptoms after operation. In 18 patients, digital ulcers healed within 2-4 weeks. Doppler and electrical impedance plethysmography examinations showed the blood circulation of affected extremities was markedly improved in the 18 patients except one who had the recurrence of digital ulcer 2 years later. In one of the 19 patients the disease recurred one month after the operation, and a lumbar sympathectomy was performed. The indications, the operative technique, and the mechanism of this operation are discussed.

Adult↗
PubMed1984

Weight gain and feed efficiency of chicks fed sucrose fatty acid esters.

Day-old Hubbard X Hubbard broilers (mixed sexes) were fed for 2 weeks with a basal diet containing 5% experimental carbohydrate. The experimental carbohydrates were one of the following: sucrose fatty acid esters (SFE)-high monoesters (SFE 1670), SFE-low monoesters (SFE 370), sucrose, glucose, or cellulose. Feed efficiency, weight gain, and growth performance were compared among treatments. Chicks fed 5% SFE 1670 showed significantly less (P less than .01) weight gain and feed efficiency than chicks fed other experimental carbohydrates. There were no significant differences (P less than .01) in weight gain and feed efficiency among groups of chicks fed SFE 370, sucrose, glucose, or cellulose. Most of the chicks fed SFE 1670 were small in size, had poor feathering, and excreted reddish-brown droppings. The appearance and droppings obtained from chicks fed SFE 370 were similar to the appearance and droppings from chicks fed sucrose, glucose, and cellulose. The SFE that contained a large proportion of monoesters (SFE 1670) resulted in poor growth of chicks, whereas SFE containing a small proportion of monoesters (SFE 370) resulted in growth performance similar to chicks on control diets.

Animals↗
PubMed1983

Effect of intravenous infusion on development of pulmonary oedema after inhalation injury.

Last year, after a systematic search of pathological and patho-physiological changes of inhalation injury in dogs, we recorded severe pulmonary oedema as early as 2 h postburn (the earliest monitoring time designed in experiment) on dogs inflicted with both body surface and severe respiratory burns without any fluid replacement during the whole course of experiment. In an analysis of cases admitted into our burn centre in the past ten years, we also found that there was no definite relationship between the incidence and severity of pulmonary oedema occurring in severe burn patients and the amount of fluid infused in the early burn phase. These facts led us to the following experiment designed to study the effect of intravenous infusion on development of pulmonary oedema after severe burns complicated with inhalation injuries.

Animals↗