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Biomedical subjects

C M Zhang

Publications and source records attributed to C M Zhang.

14 recordsLinked to original sources
PubMed2000

Suitability of immobilized metal affinity chromatography for protein purification from canola.

This work demonstrates that proper selection of a metal ion and chelating ligand enables recovery of a his(6)-tagged protein from canola (Brassica napus) extracts by immobilized metal affinity chromatography (IMAC). When using Co(2+) with iminodiacetate (IDA) as the chelating ligand, beta-glucuronidase-his(6) (GUSH6) can be purified from canola protein extract with almost homogeneous purity in a single chromatographic step. The discrimination with which metal ions bound native canola proteins followed the order Cu(2+) < Ni(2+) < Zn(2+) < Co(2+) in regard to elimination of proteins coeluted with the fusion protein. IDA- and nitrilotriacetate (NTA)-immobilized metal ions showed different binding patterns, whose cause is attributed to a more rigid binding orientation of the his(6) in forming a tridentate with Me(2+)-IDA than in forming a bidentate with Me(2+)-NTA. The more flexible binding allows for multisite interactions over the protein.

Brassica↗
PubMed2000

[Comparison of several rib rings with intercostal muscles for tracheal replacement in dogs].

OBJECTIVE: To compare the effect of several types of rib rings with intercostal muscles for the replacement of trachea in thorax. METHODS: The surface layer of the third rib of dogs were ripped off and curved into triangular, quadrilateral and polygonal form. These three types of rib rings with intercostal muscles were used to replace a segment of trachea in thorax. RESULTS: The stability of triangular rib ring was very well, but stricture of ring were often happened because of its smaller internal diameter. These stability of quadrilateral rib ring was the worst. The polygonal rib ring presented the biggest diameter and good stability compared to the other two kinds of rings. If silicone tube was supplemented in the polygonal rib ring, the quality of artificial trachea was excellent. CONCLUSION: The rib rings with intercostal muscles are successfully used for replacing the defect of trachea in canine thorax. The polygonal rib rings have the best quality in the three types of rib ring for tracheal replacement.

Animals↗
PubMed1999

[Enzymehistochemical and immunohistological changes of skeletal muscle motor end-plates and muscle fibers and their relation to the time of death].

In order to investigate the relationship between the retrograde changes of the skeletal muscle and the time of death in various postmortem intervals (PMI), a systemic study of the enzymehistochemical activity of AChE, SDH, LDH, Ca(2+)-ATPase and the immunohistochemical reaction of SYN in motor end-plates and muscle fibers was conducted in rats under different temperatures and at various PMI. The results were analyzed and compared by an image processing system. It was found that these changes were related to the PMI, especially AChE changes. The AChE could be used as a sign-enzyme of skeletal muscle to date death.

Acetylcholinesterase↗
PubMed1997

Minimally invasive cryosurgery--technological advances.

The technological advances which have caused renewed interest in cryosurgery are the development of intraoperative ultrasound to monitor the therapeutic process and the development of new cryosurgical equipment designed to use supercooled liquid nitrogen. The thin, highly efficient probes, available in several sizes, can be placed in diseased sites via endoscopy or percutaneously in minimally invasive procedures. The manner of use is to place the probe in the desired location in the diseased tissue with ultrasound guidance. If required by the size or location of the tumor, as many as five probes can be inserted and cooled to -195 degrees C simultaneously. The process of freezing is monitored by ultrasound which displays a hypoechoic (dark) image when the tissue if frozen. Rapid freezing, slow thawing, and repetition of the freeze/thaw cycle are standard features of technique. Clinical applications which have become common in the past 4 years include the treatment of prostatic cancer and liver tumors. The cases selected for cryosurgery are generally those for which no conventional treatment is possible. However, especially in prostatic cancer, the operative morbidity is so low and the results of therapy are sufficiently good in the short term to merit consideration of use in earlier stages of the disease. Diverse tumors in other sites, such as the brain, bronchus, bone, pancreas, kidney, and uterus, have also been treated in small numbers by cryosurgery. Judging from this experience, further expansion in the use of cryosurgical techniques seems certain.

Cryosurgery↗
PubMed1995

[Clinical and experimental study of yangxueshengru oral liquor in promoting puerperal breast milk secretion].

Applying Yangxueshengru Oral Liquor (YXSR) to treat 103 cases of puerperal insufficient lactation. Six hours after delivery, the parturient took YXSR, its effective rate was 98.06%. The results revealed that it could improve breast milk secretion significantly and increase daily lactation amount of parturient, insufficient lactation rate was reduced. The content of protein and trace elements (Fe, Zn and Mn, etc) in colostrum increased, the difference between medicated group and control group was significant (P < 0.05-0.001). Animal experiment showed that YXSR could increase the response of prolactin (PRL) level of model rats (P < 0.01), the serum, PRL and cortisol level of the rats were also raised significantly (P < 0.01).

Adult↗
PubMed1994

Chromatin and nucleosome organizations and DNA replication of nucleus reassembled in vitro using purified exogenous DNA and Xenopus egg extracts.

It has been demonstrated in the last ten years that the nuclear reassembly may occur in the cell-free systems from frog egg extracts added with exogenous naked DNA. However, there remains an open question: is the cell-free reassembled nucleus structurally similar to the nucleus in the intact cell? That is, does the cell-free reassembled nucleus contain nucleosomes and chromatin? For this issue, we have designed experiments for identifying the internal structures of the cell-free reassembled nucleus. These experiments show that the nucleus reassembled in vitro also contains chromatin which is composed of typical 10 nm nucleosome fibers of "beads-on-a-string", 30 nm filaments and the next higher-order structures. The digestion experiment with the enzyme micrococcal nuclease has demonstrated that the DNA in the nucleosome of the reconstituted chromatin is about 200 base pairs (bp) in length, of which 165 bp may be in the nucleosome particle, and 35 bp may be in the linker between two particles. Prolonging digestion of the 165-bp particle DNA fragment will yield a 146-bp fragment, which may be wounded in the nucleosome core. Experiments also provide evidence that the chromatin reconstitution in the cell-free reassembled nucleus is a progressive process, and that the nucleus can replicate its DNA. Based on these observations, we suppose that the chromatin of the cell-free reassembled nucleus may be structurally and functionally similar to the chromatin of the intact cells.

Animals↗
PubMed1994

[Nuclear reconstitution around purified HeLa chromosomes in a cell-free system from Xenopus eggs].

Activated Xenopus egg extracts are capable of reconstituting nucleus around the added DNA or chromatin. To understand better the nuclear reconstitution process and the structure of the assembled nucleus, we have developed a cell-free system using activated Xenopus egg extracts and metaphase chromosomes of HeLa cells. We demonstrate that the extracts are efficient promoting the decondensation of the metaphase chromosomes and the nuclear reconstitution around the chromosomes, and that the nuclear reconstitution is a precise process. The reassembled nucleus possesses a typical nuclear envelope, pore complexes, nuclear lamina, nuclear matrix, chromatin, etc., as shown by electron microscopy, embedment and embedment-free electron microscopy, and immunofluorescence method. We also found that the annulate lamellae directly take part in nuclear envelope and pore complex reconstitution by fusing with the double membrane, having reassembled on the surface of chromatin/chromosomes.

Animals↗
PubMed1993

[Repair of ruptured aneurysm of aortic sinus by sandwiching technique].

Nine cases of ruptured aneurysm of aortic sinus were successfully repaired by sandwiching technique. The abnormalities consisted of VSD (7 patients) and moderate aortic regurgitation (2). Their cardiac chest ratio was > 65%, and cardiac function was III-IV (NYHA). Follow-up showed that their cardiac murmur and thrill disappeared and cardiac function increased to I-II (NYHA). This technique is superior to others.

Adult↗
PubMed1989

[Surgical treatment of Kashin-Beck's disease of the ankle: results of long-term follow-up].

31 cases with Kashin-Beck's disease of ankle had been surgically treated by thorough debridement and were kept under observation for a period of 5 years and 10 months on average (ranging 3 years to 8 years and 9 months.). The excellent and good results were 81.81%. To achieve satisfactory result, efforts should be made to reach the goal of restoring normal relationship between the joint lines and the weight-bearing surfaces, in addition to thorough debridement, synovectomy and elimination of any impediment to motion. post-operative early movement of the ankle joint can never be over emphasized. Causes of the unsatisfactory results of the rest cases were discussed.

Adolescent↗
PubMedDate not supplied

Characteristics and developmental changes of some plasma nutrition metabolites in neonatal lambs.

Twelve spontaneously delivered Hu sheep neonatal lambs with a birth weight of 1.5-4.5 kg were used to study the characteristics and developmental changes of plasma nutrition metabolites during postnatal period in 7 days of age. The results showed that plasma glucose (Glu) concentration rose significantly within 4 h after lambing and then maintained a fluctuent upward tendency until day 7 of age. Fructose (Fru) and lactic acid (LA) concentrations were highest at 1 h after birth, tended to drop thereafter, and remained relatively stable levels after day 3 of age. Free fatty acid (FFA) tended to increase within 12 h after birth, followed by keeping comparatively high levels although decreasing fluctuently. An obvious increase of total protein (TP) occurred within 8 h after birth and then remained a relatively high concentration until day 7 of age. a-Amino nitrogen (a-NH2N) tended to rise by 4 h and fell slightly thereafter, urea nitrogen (UN) had an elevated concentration from birth to 8 h and then dropped obviously. Both a-NH2N and UN appeared to be fairly stable during the first week of age in neonatal lambs.

Amides↗