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Biomedical subjects

H Lan

Publications and source records attributed to H Lan.

At least 37 records · Page 2Linked to original sources
PubMed1998

Local regulation of macrophage subsets in the adult rat testis: examination of the roles of the seminiferous tubules, testosterone, and macrophage-migration inhibitory factor.

In the adult rat testis, macrophages belong to one of two subsets differentiated by expression or lack of expression of the resident macrophage surface antigen recognized by monoclonal antibody ED2. Local regulation of the testicular macrophage subsets was investigated in normal and 4-wk experimentally cryptorchid adult rats with and without s.c. testosterone implants (T-implants). Macrophage subsets ED2(+) (resident-type) and ED2(-) (monocyte-like) were identified immunohistochemically and counted in perfusion-fixed frozen testis sections. Depletion of the spermatogenic cells by cryptorchidism had no effect on testicular macrophage numbers. Inhibition of Leydig cell and seminiferous tubule function by low-dose (3 cm) T-implants caused a 40% reduction in ED2(+) resident macrophages in both scrotal and abdominal testes. High-dose (24 cm) T-implants, which inhibit Leydig cell function while maintaining normal seminiferous tubule function, also reduced the number of resident macrophages by approximately 40%, although this reduction was at least partially prevented in the abdominal testes. In the scrotal testis only, the ED2(-) monocyte/macrophage subset was significantly reduced in number by low-dose, but not high-dose, T-implants. The concentration of the Leydig cell-secreted cytokine macrophage-migration inhibitory factor (MIF) in testicular fluid was reduced by cryptorchidism, but not by the T-implants. When data from all experimental groups were combined, ED2(+) resident macrophage numbers showed a significant positive correlation with parameters of Leydig cell function (serum LH and testicular testosterone levels) but a negative correlation with MIF levels. This study indicates that Leydig cells regulate testicular macrophage numbers directly, rather than via an effect upon the seminiferous epithelium, in the adult rat testis. The data also suggest that testosterone and MIF play only a minor role, if any, in this regulation.

Animals↗
PubMed1998

Transurethral prostate vaporization using an oval electrode in 82 cases of benign prostatic hyperplasia.

OBJECTIVE: To present our initial experience in transurethral vaporization of the prostate (TVP) using an oval electrode for the treatment of benign prostatic hyperplasia (BPH). METHODS: A total of 82 patients underwent TVP procedures with the oval electrode. The newly designed oval-shaped electrode can work with a High Frequency Electrosurgery Unit. Prostate gland tissue was vaporized through an Fr 24 percutaneous nephroscope transurethrally. The operation procedure was similar to transurethral resection of the prostate (TURP) or transurethral laser prostatectomy (TULP). Power setting ranged from 240 W to 320 W. Local vaporization temperature reached 120 degrees C. RESULTS: Urination was recovered in all 82 patients after TVP. Mean post-treatment International Prostate Symptom Score (I-PSS) reduced from 27.10 to 5.05; mean bladder residual urine volume dropped from 147.71 ml to 33.2 ml; and mean urine flow rate (MFR) increased from 4.45 ml/s to 14.57 ml/s (P < 0.01). The initial results of short-term follow-up were excellent. CONCLUSIONS: TVP with the oval electrode is easy to perform and causes less hemorrhage and few complications. It especially benefits elderly and/or critically-ill patients. We believe that TVP with our oval electrode is feasible with low risk.

Aged↗
PubMed1997

Experimental study on the effects of aprotinin on myocardial ischemia and reperfusion.

Direct effects of a high-dose aprotinin on the normally perfused hearts and the myocardial protection after ischemia and reperfusion were investigated in an isolated working rat heart model. In trial I, hearts had no ischemia and were perfused with either K-H solution or the K-H solution containing aprotinin (200 KIU/ml) for 55 min. No statistically significant difference was observed in hemodynamics between the two groups. In trial II, hearts were exposed to 150 min period of global ischemia at 15 degrees C with 4 degrees C multidose St. Thomas' II solution (STS). The control group I received normal K-H solution; the group II was treated with the solution with aprotinin added. The group III was similar to the group I and received the STS enriched with aprotinin. On reperfusion, the recovery of hearts in group III was significantly better than those of the group I and II, as reflected by better hemodynamics and myocardial ATP levels and milder myocardial ultrastructural injury. There was no difference between the group I and II. These results suggest that the aprotinin a dose of 200 KIU/ml has no harmful effects on normally perfused hearts and has a marked myocardial protective effect on the prolonged myocardial ischemia when used in cold crystalloid cardioplegia.

Animals↗
PubMed1997

Experimental study on modified treatment and endothelialization of bovine pericardial valves.

The purpose of this study were to confirm whether the modified treatment with L-glutamic acid could attenuate the calcification of the GA-fixed valves and improve its biocompatibility. Pericardial valves were routinely treated with GA and valves were treated with GA and 8% L-glutamic acid. The valves treated with these methods were implanted subcutaneously in rats. Calcium deposits of the valves collected at the 7th, 21st, 60th, 90th day were assessed by atomic absorption spectroscopy, and the pathologic changes were examined by light and electron microscopy. Cultured endothelial cells (ECs) were seeded onto the valves. The cell counts were determined at the 1st, 4th, 7th, 10th day after seeding. PGI2 in culture medium was tested at the 10th day. Transmission and scanning electron microscopy were used to observe the growth of ECs on the valves. Results showed that subsequent treatment with L-glutamic acid could significantly mitigate calcification of bovine pericardial valves as compared with simple GA-fixed valves (P < 0.01). ECs seeded on the GA treated valves died within 4 days. On the valves treated by modified method, ECs could proliferate and release PGI2. It is concluded that treatment with L-glutamic acid can markedly inhibit the calcification and improve the biocompatibility of bioprosthetical valves.

Animals↗
PubMed1997

Effect of amino acid cardioplegia on myocardial metabolism and function of ischemic canine heart.

To evaluate the effect of amino acid cardioplegia on myocardial metabolism and function of ischemic canine heart, canine cardiopulmonary bypass (CPB) model was established and the dog heart was subjected to a 120 min ischemic arrest. Animals were divided into 3 groups, group 1: warm blood cardioplegia induction and terminal perfusion plus 4 C ST. Thomas hospital solution (STS) during ischemia; group 2: warm blood cardioplegia enriched with amino acid (L-asparte and L-glutamate 13 mmol/L each) and STS without amino acid (A. G.) and group 3: both warm blood cardioplegic solution and STS enriched with A. G. . The result demonstrated that the cardiac function of animals in group 2 and 3 had a significantly better recovery after ischemic-re-perfusion. By the end of ischemia the content of myocardial ATP in group 3 was distinctly higher than that in group 1 (P < 0.05), with the release of cardiac enzyme being the least. Myocardial ultra-structure almost remained intact before and after ischemia. Our experiment suggests that the cardioplegia arrest with warm blood and cold crystalloid solution enriched with amino acids could diminish the ischemia-re-perfusion injuries of the heart and enhance the effect of myocardial protection.

Amino Acids↗
PubMed1997

[Genetic diversity and phylogenetic relationships among Chinese Macacas based on protein electrophoresis].

In this paper, using protein electrophoresis method, we studied proteinpolymorphism and genetic divergence of 5 species in Genus Macaca: M. mulatta, M. arctoides, M. assamensis, M. thibetana, M. fascicularis. A total of 30 genetic loci were analyzed for 29 individuals, including 4 Nycticebus pygmaeus as outgroup. For the 19 M. mulatta, 9 loci were found to be polymorphic. Accordingly, the percentage of polymorphic loci, P = 0.3; the mean number of alleles, A = 1.4, and the mean heterozygosity, H = 0.1045, indicating a rather high level of genetic diversity in this species. Furthermore, 10 loci showed polymorphic among the 5 species, which can be used as information loci for phylogenetic reconstruction. Three programs (conml, neighbor, fitch) in PHYLIP 3.5 c were chosen to construct phylogenetic trees. All of the three trees show support a close relationship between M. mulatta and M. fascicularis. However, two trees have the same topology, suggesting that M. arctoides belongs to an independent species group, while M. assamensis and M. thibetana are closely related and belong to another species group, and the other tree gives a different topology which implies that M. arctoides, M. assamensis and M. thibetana belong to one species group.

Animals↗
PubMed1996

Surgical treatment of ascending aortic dissecting aneurysm--clinical application of modified Cabrol's operation.

This paper reported 3 cases of ascending aortic dissecting aneurysm treated by modified Cabrol's operation. An 8 mm Gore-Tex connected with coronary arteries was employed to prevent high tension, intimal tearing and bleeding of anastomosis. Unremoved aneurysmal wall used as a sac for enclosing conduit graft could minimize the bleeding and oozing so that leaked blood can be drained to right atrium via a bypass.

Adult↗
PubMed1996

The observation of complement activation and polymorphonuclear neutrocytopenia during cardiopulmonary bypass.

By determining the plasma levels of C2, C4, factor B and polymorphonuclear neutrophils (PMNs) of the patients who received CPB, the path of complement activation and changes of PMNs were studied. The results suggest that complement system was activated through alternative pathway during CPB and was activated through classic pathway after CPB. The anaphylatoxin, the products of complement activation may be responsible for the polymorphonuclear neutrocytopenia.

Adolescent↗
PubMed1996

Skeletal muscle lymphoma: observations at MR imaging.

We present the MR appearances of three patients with biopsy-proven primary lymphoma of skeletal muscle. In each case lymphoma resulted in bulky expansion of the involved muscle, homogeneously isointense to skeletal muscle on T1-weighted images, homogeneously hyperintense to skeletal muscle on T2-weighted images and diffusely enhancing following intravenous administration of gadopentate dimeglumine.

Adult↗
PubMed1996

[Phylogenetic relationships among six species of Macaca inferred from ribosomal DNA variations].

Restriction maps of ribosomal DNA repeating units of six species of Macaca (M. mulatta, M. facsicularis, M. arctoides, M. assamensis, M. thibetana, M. nemestrina) and two outgroup species, Rhinopithecus bieti and Hylobates leucogenys, were constructed with 15 restriction endonucleases and 28S, 18S rDNA probes cloned from human, M. arctoides shares a common restriction map with M. assamensis. Phylogenetic tree derived from the neighbor-joining was somewhat different that derived from the maximum likelihood methods using the NEIGHBOR and RESTML program in PHYLIP version 3.5c. However, the consensus of our phylogenetic trees supports the viewpoint that M. facsicularis and M. mulatta were maybe diverged first in the genus Macaca. Further studies using DNA sequencing method are required to resolve the phylogeny of the genus Macaca.

Animals↗
PubMed1995

Phylogeny of Muntiacus (Cervidae) based on mitochondrial DNA restriction maps.

Mitochondrial DNA restriction maps for 12 restriction enzymes of four species of muntjacs--Indian muntjac (M. muntjak), Gongshan muntjac (M. gongshanensis), black muntjac (M. crinifrons), and Chinese muntjac (M. reevesi)--were compared to estimate the phylogenetic relationships among them. Phylogenetic trees were constructed by both distance and parsimony methods. The two resulting trees share a similar topology, which indicates that the black muntjac and the Gongshan muntjac are closely related, followed by the Chinese muntjac; the Indian muntjac is the sister taxon to all the other muntjacs.

Animals↗
PubMed1995

The application of skin external expander to postburn advanced scar contracture.

In recent years, the universally used internal expansion by implanting a silicone elastomer balloon into the soft tissue under the skin has shown certain disadvantages, i.e., certain complications associated with the operation, high cost, and the fact that the materials cannot be recycled. That the materials are used only once adds to the operating cost. In view of these disadvantages, we have designed and developed a kind of mechanical external skin expander, which is composed of (1) an adjustable tractor, (2) preserving splints, and (3) a traction frame. The tractor is used to grip the contracted skin in order to make the soft tissue of the skin expand with the lapse of time and increase in traction weight. The external skin expansion has the following advantages compared with internal expansion: avoiding the complications caused by implanting the soft-tissue expander beneath the skin; simplicity and efficiency of operation; and the fact that the equipment can be reused, reducing the operating which is suitable for these basic units. The data of the expanded skin area can be calculated through the computer. Since June of 1993, a satisfactory curative effect has been obtained in 44 patients suffering from advanced postburn scars. Thirty-two patients among them were treated for more than half a year, with the scar becoming normal in both appearance and function. External skin expansion provides a new method for expansion of skin soft tissue. It has a bright future in its clinical application.

Adolescent↗
PubMed1995

Phylogenetic relationships among two species of golden monkey and three species of leaf monkey inferred from rDNA variation.

Restriction maps of rDNA repeats of five species of Colobinae and three outgroup taxa, Hylobates leucogenys, Macaca mulatta, and Macaca irus, were constructed using 15 restriction endonucleases and cloned 18S and 28S rRNA gene probes. The site variation between Rhinopithecus roxellana and Rhinopithecus bieti is comparable to that between Presbytis françoisi and Preshytis phayrei, implying that R. bieti is a valid species rather than a subspecies of R. roxellana. Phylogenetic analysis on the 47 informative sites supports the case for Rhinopithecus being an independent genus and closely related to Presbytis. Furthermore, branch lengths of the tree seem to support the hypothesis that the leaf monkeys share some ancestral traits as well as some automorphic characters.

Animals↗
PubMed1995

[The mitochondrial DNA diversity of pigs in southwest China].

Twenty restriction endonucleases, ApaI, AvaI, BamHI, BclI, BglI, BglII, ClaI, EcoRI, EcoRV, HindIII, HpaI, KpnI, PstI, PvuII, SacI, SalI, ScaI, SmaI, XbaI, XhoI were used to investigate the mitochondrial DNA polymorphism of pigs from 11 localities in southwest China. Among the 28 animals analyzed, 27 restriction morphs were detected, which can be sorted into 6 haplotypes. The average genetic distance among haplotypes (P) is 0.004, and the value of average sequence variation in pig population (pi) is 0.122%. Our results suggest that the genetic diversity within the pigs is remarkably scarce. The pigs in southwest China may have origineted from a late common ancester, and were likely impacted by the founder effect.

Animals↗
PubMed1995

[Surgical treatment of ascending aortic dissecting aneurysm with Cabrol's operation in 3 patients].

Form Mar. 1993 to Dec. 1994, 3 patients with ascending aortic dissecting aneurysm underwent aneurysmal incision, artificial vessel interposition, aortic valvular replacement and coronary artery transposition as Cabrol's operation. All recovered health discussed. The procedures and techniques were modified on the Cabrol's. Anastomosis of coronary openings with 8 mm Gore-tex tube obtained good match, little tension, and avoided intimal tear around coronary ostia and blood leakage of the anastomosis. We have created a self blood infusion system to stop hemorrhage of vessel graft or anastomosis by a bypass between right atrium and aneurysmal sac around the dacron graft.

Adult↗
PubMed1994

Multiple genotypes of mitochondrial DNA within a horse population from a small region in Yunnan Province of China.

mtDNA genotypes of six domestic horses (three adult short horses whose heights are under 1 m and three common domestic horses) from a small region of 15 km2 in Malipo county of Yunnan province of China were investigated by the technique of restriction fragment length polymorphism (RFLP) with 16 restriction endonucleases which recognize 6-bp sequences. An average of 56 fragments for an individual was obtained. Unlike other domestic animals, this population of horses exhibits high mtDNA genetic diversity. Each of the six horses has a specific mtDNA genotype showing a pattern of multiple maternal origins, as suggested by fossil and literature records. We think the population of horses is an amazing seed-resource pool of horses and hence deserves to be paid more attention from the view of conservation genetics. However, it is also remarkable that we did not find any typical mtDNA genetic markers which would discriminate between short horses and common domestic horses.

Animals↗
PubMed1993

The origin and genetic differentiation of native breeds of pigs in southwest China: an approach from mitochondrial DNA polymorphism.

Mitochondrial DNA (mtDNA) of six breeds of native domestic pigs from Yunnan province, southwest China, and two wild boars obtained from Sichuan, China, and Vietnam was analyzed using 20 restriction endonucleases that recognize six nucleotides. Restriction maps were made by double-digestion methods and polymorphic sites were located on the map. According to their mtDNA restriction types, all the breeds were classified into six groups. Genetic distances among groups were calculated to define their phylogenetic relationships. The relationship between the Sichuan wild boar and domestic pigs is close, while the Vietnamese wild boar is relatively far from them, so the domestic pigs in southwest China are likely to have originated from a wild pig which distributed in west China. We compare our results with previous reports in literature and discuss the relationship among Chinese pigs, Japanese pigs, and European pigs. The mtDNA cleavage pattern of the Mingguang pig digested by EcoRV was identical to that of Duroc; mutations at the EcoRI site, detected in the mtDNA of two Dahe pigs, are the same as in the Vietnamese wild boar, suggesting that mutational hot spots exist in the mtDNA of pigs.

Animals↗