Exploring functional genes' correlation with (S)-equol concentration and new daidzein racemase identification.

With its estrogenic activity, (S)-equol plays an important role in maintaining host health and preventing estrogen-related diseases. Exclusive production occurs through the transformation of soy isoflavones by intestinal bacteria, but the reasons for variations in (S)-equol production among different individuals and species remain unclear. Here, fecal samples from humans, pigs, chickens, mice, and rats were used as research objects. The concentrations of (S)-equol, along with the genetic homology and evolutionary relationships of (S)-equol production-related genes [daidzein reductase (DZNR), daidzein racemase (DDRC), dihydrodaidzein reductase (DHDR), tetrahydrodaidzein reductase (THDR)], were analyzed. Additionally, in vitro functional verification of the newly identified DDRC gene was conducted. It was found that approximately 40% of human samples contained (S)-equol, whereas 100% of samples from other species contained (S)-equol. However, there were significant variations in (S)-equol content among the different species: rats > pigs > chickens > mice > humans. The distributions of the four genes displayed species-specific patterns. High detection rates across various species were exhibited by DHDR, THDR, and DDRC. In contrast, substantial variations in detection rates among different species and individuals were observed with respect to DZNR. It appears that various types of DZNR may be associated with different concentrations of (S)-equol, which potentially correspond to the regulatory role during (S)-equol synthesis. This enhances our understanding of individual variations in (S)-equol production and their connection with functional genes in vitro. Moreover, the newly identified DDRC exhibits higher potential for (S)-equol synthesis compared to the known DDRC, providing valuable resources for advancing in vitro (S)-equol production. IMPORTANCE: (S)-equol ((S)-EQ) plays a crucial role in maintaining human health, along with its known capacity to prevent and treat various diseases, including cardiovascular diseases, metabolic syndromes, osteoporosis, diabetes, brain-related diseases, high blood pressure, hyperlipidemia, obesity, and inflammation. However, factors affecting individual variations in (S)-EQ production and the underlying regulatory mechanisms remain elusive. This study examines the association between functional genes and (S)-EQ production, highlighting a potential correlation between the DZNR gene and (S)-EQ content. Various types of DZNR may be linked to the regulation of (S)-EQ synthesis. Furthermore, the identification of a new DDRC gene offers promising prospects for enhancing in vitro (S)-EQ production.

Clinical outcomes of endoscopic versus laparoscopic resection for senile patients with gastric gastrointestinal stromal tumours (2 to 4 cm) originating from the muscularis propria layer.

Introduction: Currently, there still are no selection criteria for endoscopic resection (ER) versus laparoscopic resection (LR) of gastric gastrointestinal stromal tumours (GIST) (2 to 4 cm) originating from the muscularis propria layer (MP-GISTs). Aim: To investigate and compare the long-term prognosis of ER and LR for resecting gastric MP-GISTs, with at least 5 years of follow-up. Material and methods: Between January 2010 and December 2015, 134 patients with gastric MP-GISTs were consecutively enrolled in this study. The main comparison measurements included the short-term and long-term outcomes between the ER group (n = 89) and the LR group (n = 45). Results: In this study, there were no significant differences in the rates of complete resection (p = 0.220) and short-term complications (p = 0.663) between the ER group and the LR group. The ER group had a shorter operation time (50.1 ±18.2 min vs. 120.6 ±32.5 min, p < 0.001), shorter hospital stays (5.1 ±1.9 days vs. 6.4 ±3.7 days, p = 0.026), and lower hospitalization costs (16639.5 ±5091.3 CNY vs. 24030.4 ±6803.1 CNY, p < 0.001) than the LR group. The ER group had a lower rate of long-term complications than the LR group (p = 0.001) during the follow-up period (84.2 ±17.9 months vs. 89.0 ±16.8 months, p = 0.207). Conclusions: Our results showed that ER was a more feasible treatment approach than LR when the gastric MP-GIST was located in or near the cardia/pylorus. ER also had several other advantages over LR, such as a shorter procedure time, shorter hospital stay, and lower hospitalization costs.

[Research progress on chemical constituents and quality control methods of Succus Bambusae].

Through the investigation of a large number of both domestic and overseas literatures and related quality standards, chemical compositions, quality evaluation system and quality control methods of Succus Bambusae were systematic summarized in this study. There were abundant chemical constituents in Succus Bambusae, mainly including volatile ingredients, amino acids, flavonoids, trace elements and vitamins, with high medicinal and edible value. The quality control methods involved traditional morphological identification, spectroscopy, chromatography and other techniques. However, the current quality standards of Succus Bambusae are relatively low, lacking safety indicators, and cannot effectively ensure its quality, seriously affecting the safety and effectiveness of its clinical use. Therefore, it is particularly important to establish a set of highly sensitive and specific quality evaluation system for Succus Bambusae. In this paper, the current research status of the chemical compositions and quality standards of Succus Bambusae were reviewed, with the purpose of providing a basis for further improvement of its quality evaluation system.

[Research progress of pesticide residues in Chrysanthemum].

Chrysanthemum is widely used as a type of edible flower and also considered as the important materials of many beverages in China. Due to the occurrence of diseases and pests, and the lack of regulations for species, frequency, dose of pesticides in Chrysanthemum, pesticides have become one of the main pollutants in Chrysanthemum. The pesticide residues in Chrysanthemum were detected frequently and worth noting. This paper focused on the types of pesticides, pesticide residue detection techniques, and risk assessment methods for Chrysanthemums on the basis of relevant literatures. The pesticide residues of traditional Chinese medicine are mainly organochlorines, organophosphorus and pyrethroids, and the detection techniques include gas chromatography(GC), liquid chromatography(LC) or both combined with mass spectrometry(MS). With the increasing use of traditional Chinese medicine, Chrysanthemum is widely circulated in the market. Therefore, it is important to understand the current situation of pesticide residues in different varieties of Chrysanthemum, so as to provide theoretical reference for the control of quality and safety of Chrysanthemum and the formulation of the maximum residue limit.

The Effects of Sidt2 on the Inflammatory Pathway in Mouse Mesangial Cells.

In patients with chronic kidney disease, the abnormal activation of inflammatory pathways is usually an important factor leading to renal fibrosis and further deterioration of renal function. Finding effective intervention targets of the inflammatory signaling pathway is an important way to treat chronic kidney disease. As a newly discovered lysosomal membrane protein, the correlation between SID1 transmembrane family member 2 (Sidt2) and the inflammatory signaling pathway has not been reported. The aim of this study was to investigate the effect of Sidt2 on inflammation by inhibiting the expression of the Sidt2 gene in a mouse mesangial cell line mediated by a lentiviral CRISPR/Cas9 vector. Hematoxylin and eosin staining and microscopy found that the mesangial cells lost their normal morphology after inhibiting the expression of Sidt2, showing that the cell body became smaller, the edge between the cells was unclear, and part of the nucleus was pyknotic and fragmented, appearing blue-black. The expressions of IKK ß, p-IKK α/ß, NF-κB p65, p-NF-κB p65, p-IκBα, IκBα, and TNF-α in the NF-κB pathway of the Sidt2 -/- group were higher than those of the Sidt2 +/+ group. p-Jak2 and IL6 increased in the Jak/Stat pathway, and p-ERK and p-P38 increased in the MAPK pathway. The expressions of IKK ß, p-IKK α/ß, NF-κB p65, p-NF-κB p65, p-IκBα, IκBα, and TNF-α in the NF-κB pathway of the Sidt2 +/++LPS group were significantly higher than those in the Sidt2 +/+ group. The expressions of IKK ß, p-IKK α/ß, NF-κB p65, p-NF-κB p65, p-IκBα, IκBα, and TNF-α in the Sidt2 -/-+LPS group were higher than those in the Sidt2 -/- group. The expressions of p-IKK α/ß, NF-κB p65, p-NF-κB p65, p-IκBα, IκBα, and TNF-α in the Sidt2 -/-+LPS group were higher than those in the Sidt2 +/++LPS group. In the Jak/Stat pathway, the protein expressions of p-Jak2 and IL6 in the Sidt2 +/++LPS group were higher than those in the Sidt2 +/+ group. The expressions of p-Jak2 and IL6 in the Sidt2 -/-+LPS group were higher than those in the Sidt2 -/- group. The expressions of p-Jak2 and IL6 in the Sidt2 -/-+LPS group were higher than those in the Sidt2 +/++LPS group. The expressions of p-JNK, p-ERK, p-P38, and ERK in the MAPK pathway in the Sidt2 +/++LPS group were higher than those in the Sidt2 +/+ group. The expressions of p-JNK, p-ERK, p-P38, and ERK in the Sidt2 -/-+LPS group were higher than those in the Sidt2 -/- group. The expressions of p-JNK, p-ERK, p-P38, and ERK in the Sidt2 -/-+LPS group were higher than those in the Sidt2 +/++LPS group. These data suggested that deletion of the Sidt2 gene changed the three inflammatory signal pathways, eventually leading to the damage of glomerular mesangial cells in mice.

Morphological features of complex congenital cardiovascular anomalies in fetuses: as evaluated by cast models.

Accurate prenatal diagnosis of complex congenital cardiovascular anomalies, vascular ones in particular, is still challenging. A fetal cardiovascular cast model can provide a copy of the cardiac chambers and great vessels with normal or pathological structures. This study was aimed to demonstrate three-dimensional anatomy of complex congenital cardiovascular anomalies in fetuses by means of corrosion casting. Twenty fetuses with prenatal-ultrasound-diagnosed complex cardiovascular anomalies were enrolled in this study (19 to 35 gestational weeks). Fetal cardiovascular cast models were made by a corrosion casting technique. The specimens were injected with casting material via the umbilical vein, and then immersed in strong acid after casting fluid was solidified, to disclose the geometries of cardiovascular cavities. Nineteen cast models were successfully made from 20 specimens. The casts distinctly showed the morphological malformations and spatial relationship between cardiac chambers and great vessels. One hundred and eleven abnormalities were revealed by casting in the 19 specimens, including 34 abnormalities located in the cardiac chambers (3, 4 and 27 anomalies in the atria, atrioventricular valves and ventricles, respectively), and 77 in the great vessels (28, 20, 24 and 5 anomalies in the aorta and its branches, the pulmonary artery, the ductus arteriosus and the major veins, respectively). Corrosion casting can display three-dimensional anatomy of fetal complex cardiovascular anomalies. This improves our understanding of related pathomorphology and prenatal diagnosis.

Identification of Bacterial Surface Antigens by Screening Peptide Phage Libraries Using Whole Bacteria Cell-Purified Antisera.

Bacterial surface proteins can be good vaccine candidates. In the present study, we used polyclonal antibodies purified with intact Erysipelothrix rhusiopthiae to screen phage-displayed random dodecapeptide and loop-constrained heptapeptide libraries, which led to the identification of mimotopes. Homology search of the mimotope sequences against E. rhusiopthiae-encoded ORF sequences revealed 14 new antigens that may localize on the surface of E. rhusiopthiae. When these putative surface proteins were used to immunize mice, 9/11 antigens induced protective immunity. Thus, we have demonstrated that a combination of using the whole bacterial cells to purify antibodies and using the phage-displayed peptide libraries to determine the antigen specificities of the antibodies can lead to the discovery of novel bacterial surface antigens. This can be a general approach for identifying surface antigens for other bacterial species.

Morphological Features of Complex Congenital Cardiovascular Anomalies in Fetuses: as Evaluated by Cast Models / 华中科技大学学报（医学）（英德文版）

Accurate prenatal diagnosis of complex congenital cardiovascular anomalies,vascular ones in particular,is still challenging.A fetal cardiovascular cast model can provide a copy of the cardiac chambers and great vessels with normal or pathological structures.This study was aimed to demonstrate three-dimensional anatomy of complex congenital cardiovascular anomalies in fetuses by means of corrosion casting.Twenty fetuses with prenatal-ultrasound-diagnosed complex cardiovascular anomalies were enrolled in this study (19 to 35 gestational weeks).Fetal cardiovascular cast models were made by a corrosion casting technique.The specimens were injected with casting material via the umbilical vein,and then immersed in strong acid after casting fluid was solidified,to disclose the geometries of cardiovascular cavities.Nineteen cast models were successfully made from 20 specimens.The casts distinctly showed the morphological malformations and spatial relationship between cardiac chambers and great vessels.One hundred and eleven abnormalities were revealed by casting in the 19 specimens,including 34 abnormalities located in the cardiac chambers (3,4 and 27 anomalies in the atria,atrioventricular valves and ventricles,respectively),and 77 in the great vessels (28,20,24 and 5 anomalies in the aorta and its branches,the pulmonary artery,the ductus arteriosus and the major veins,respectively).Corrosion casting can display three-dimensional anatomy of fetal complex cardiovascular anomalies.This improves our understanding of related pathomorphology and prenatal diagnosis.

Cardiovascular cast model fabrication and casting effectiveness evaluation in fetus with severe congenital heart disease or normal heart.

To investigate the application and effectiveness of vascular corrosion technique in preparing fetal cardiovascular cast models, 10 normal fetal heart specimens with other congenital disease (control group) and 18 specimens with severe congenital heart disease (case group) from induced abortions were enrolled in this study from March 2013 to June 2015 in our hospital. Cast models were prepared by injecting casting material into vascular lumen to demonstrate real geometries of fetal cardiovascular system. Casting effectiveness was analyzed in terms of local anatomic structures and different anatomical levels (including overall level, atrioventricular and great vascular system, left-sided and right-sided heart), as well as different trimesters of pregnancy. In our study, all specimens were successfully casted. Casting effectiveness analysis of local anatomic structures showed a mean score from 1.90±1.45 to 3.60±0.52, without significant differences between case and control groups in most local anatomic structures except left ventricle, which had a higher score in control group (P=0.027). Inter-group comparison of casting effectiveness in different anatomical levels showed no significant differences between the two groups. Intra-group comparison also revealed undifferentiated casting effectiveness between atrioventricular and great vascular system, or left-sided and right-sided heart in corresponding group. Third-trimester group had a significantly higher perfusion score in great vascular system than second-trimester group (P=0.046), while the other anatomical levels displayed no such difference. Vascular corrosion technique can be successfully used in fabrication of fetal cardiovascular cast model. It is also a reliable method to demonstrate three-dimensional anatomy of severe congenital heart disease and normal heart in fetus.

Characterization of Seven New Polystyrene Plates Binding Peptides from a Phage-Displayed Random 12-Peptide Library.

A random 12-peptide library was screened against Erysipelothrix rhusiopthiae and porcine circovirus 2 recombinant Cap protein and the selected peptides were used for detecting the corresponding pathogens quickly and effectively. To our surprise, seven peptides, P1 (WHWNAP WWNGVY), P2 (FHWTWQFPYTST), P3 (GAMHLPWHMGTL), P4 (HWNIWWQHHPSP), P5 (HFFKWHTRTNDQ), P6 (HFFRWHPSAHLG) and P7 (HFAYWWNGVRGP) with the characteristics of polystyrene plate (PS) binding target-unrelated peptides (TUPs), were selected from the library. It has been found that P2 and P4 shared common motif of plastic binding peptide, moreover, P2, P3, P5 and P7 have been isolated repeatedly in other research groups using different targets. Then, the seven peptide phage clones were identified as the PS binding TUP phages by phage-ELISA and elution titration, particularly, P1 and P2 showed strong PS binding affinity which can not be inhibited by usual blocking buffers. In addition, all of the phages were not propagation-related TUP, but P3 showed the similar propagation rate with M13KE (vector phage). We also found that the seven PS-TUPs are rich in W, H, F, P and G, particularly, both W and H are contained in all PS-TUPs. It deduced that they may play a potential role in peptide binding to plastic. Although it is difficult to eliminate the TUP phages in phage display completely, these PS-TUPs can be used to exclude the false positive peptides rapidly and effectively and help us to obtain truly interesting peptides more accurately.

[Effects of biochar on CO2 and N2O emissions and microbial properties of tea garden soils].

To clarify the effects of biochar addition (0.5%, 1.5%, 2.5%, 3.5%) on the emission of carbon dioxide (CO2) and nitrous oxide (N2O), pH and microbial communities of the tea garden soil, an indoor incubation experiment was conducted using the acidulated tea-planted soil. Results showed that the emissions of CO2 and N2O and the rate of C, N mineralization were increased in a short term after the addition of biochar compared with the control, while the promoting effect was weakened along with increasing the addition of biochar. The pH, dehydrogenase activity and microbial biomass carbon were increased in the biochar treatments. Phospholi-pid fatty acid (PLFA) with different markers was measured and the most PLFA was detected in the group in the 1.5% biochar treatment with significant differences (P<0.05) compared with the control. In addition, the higher levels of 16:0, 14:0 (bacteria), 18:lω9c (fungi), l0Me18:0 (actinomycetes) groups were observed and there were significant differences (P <0.05) in individual phospholipid fatty acid among the different treatments. Taken together, the acidulated tea-planted soil, soil microbial biomass and microbial number were improved after addition of biochar.

[Toxoplasma gondi Antibody Profile in Patients with Leukemia or Lymphoma].

Blood samples were collected from patients with leukemia (n = 150) or lymphoma (n = 150) in the Cancer Hospital from March to September 2014. The specific antibodies (IgG, IgM) to, and circulating antigens (CAg) of Toxoplasma gondii were determined by ELISA. A 529 bp specific sequence was amplified by PCR from the genomic DNA of T. gondii. T. gondii-specific IgG positive rate in patients with leukemia and lymphoma were 16.0% (24/150) and 20.0% (30/150), respectively, which were significantly higher than that of healthy persons (6.4%, 7/110) (P < 0.05). IgM positive rate of the leukemia patients, lymphoma patients, and healthy persons was 2.7% (4/150), 1.3% (2/150), and 0.9% (1/110) (P > 0.05), respectively. No significant difference was found in IgM and CAg positive rate among leukemia patients, lymphoma patients, and healthy persons (P > 0.05). No specific band (529 bp) was detected in all samples.

Epitope screening of the PCV2 Cap protein by use of a random peptide-displayed library and polyclonal antibody.

Capsid protein (Cap), the only structural protein of porcine circovirus 2 (PCV2), is involved in the host protective response and is a target for vaccine development. To find a rapid and easy way to fully map the antigenic epitopes of Cap, purified Cap-specific polyclonal antibodies were used to screen a random heptapeptide phage display library. After three rounds of screening, twenty phage clones that had binding activity to Cap-specific antibodies (tested by phage ELISA) were sequenced. When the inserted amino acid sequences were aligned with the Cap protein sequence, eight core regions in Cap ((50)SRTFGYT(56), (62)VRTPSW(67), (68)AVDMMR(73), (79)FLPPGG(84), (86)SNPRSVPF(93), (102)KVEFWP(107), (119)GSSXXXLDDN(128) and (229)PPLNP(233)) were identified, three of which ((50)SRTFGYT(56), (86)SNPRSVPF(93) and (102)KVEFWP(107)) for the first time. Nine phagetopes representing the eight regions were chosen to immunize Kunming mice. All except minotopes (50)SRTFGYT(56) and (229)PPLNP(233) induced antibodies against PCV2 when injected into Kunming mice.

Phylogenetic analysis using E2 gene of classical swine fever virus reveals a new subgenotype in China.

Outbreaks of classical swine fever (CSF) have caused serious economic consequences in China. Phylogenetic analysis based on full-length E2 gene sequences showed that five classical swine fever virus (CSFV) isolates collected from Hunan province in 2011 and 2012, together with seven other isolates from neighboring provinces, Guangdong (5) and Guangxi (2), could be classified as a new subgenotype 2.1c, which may have been endemic in the south of China for at least fourteen years. Subgenotype 2.1c isolates share 90.2-94.9% and 89.9-93.8% nucleotide sequence similarity separately with those of subgenotype 2.1a and 2.1b in E2 gene, which are lower than the nucleotide identities between subgenotype 2.1a and 2.1b (91.1-95.7%). Further analysis based on a partial E2 gene sequence (216 nt) indicated that subgenotype 2.1c isolates are also circulating in Thailand. Alignment of E2 amino acid sequences showed that subgenotype 2.1c isolates exhibit a SPA → TPV substitution at positions 777 and 779 compared with subgenotypes 2.1a and 2.1b.

Complete genome sequences of classical Swine Fever virus isolates belonging to a new subgenotype, 2.1c, from hunan province, china.

Two isolates of a new classical swine fever virus (CSFV) subgenotype, 2.1c (HNLY-2011 and HNSD-2012), were recently isolated from pigs in Hunan Province, China. The most significant difference in the amino acid sequences of the polyproteins from subgenotypes 2.1a and 2.1b is an SPA → TPV amino acid substitution at positions 777 and 779 in the E2 protein.

2,4-Dichloro-7-fluoro-quinazoline.

The mol-ecule of the title compound, C(8)H(3)Cl(2)FN(2), is essentially planar, with a maximum deviation of 0.018 (2) Å. In the crystal, π-π stacking is observed between parallel quinazoline moieties of adjacent mol-ecules, the centroid-centroid distance being 3.8476 (14) Å.

[Reconstruction of rabbit urethra using urethral extracellular matrix].

OBJECTIVE: To evaluate the feasibility of reconstruction of rabbit urethra using urethral extracellular matrix. METHODS: Extracellular matrix was obtained from the urethra of 20 donor New Zealand rabbits. In experimental group, 20 rabbits underwent segmental urethral resection (about 1.0 to 1.5 cm in length) and the defects were replaced by a tube of extracellular matrix. The serum TNFalpha was detected by ELISA to assess the immunity response preoperatively and 12, 24, 48 h postoperatively. The regenerated urethral segments were taken for histologic and pathologic study 10 days, 3 weeks, 6 weeks and 24 weeks after operation. The urodynamics, urethroscopy and urethrography were also performed. RESULTS: The serum TNFalpha in experiment group slightly rised, with no significant difference when compared with that in control group. 10 days after operation, epithelial cell migrated into the extracellular matrix from two ends, and small vessels were also found. 3 weeks later, several layers of urothelium covered the whole surface of the matrix tube. 6 weeks later, the irregularly arranged smooth muscle fibers were fist observed by Van Gieson staining. 24 weeks after operation, the smooth muscle cells increased, the appearance of the regenerated urethra segments were very similar to normal urethral wall components. The urethrography and urodynamic evaluation revealed no difference between the normal and the regenerated urethral tube. CONCLUSIONS: The urethral extracellular matrix might be an ideal replacement material for urethral defect.

Curative effect and histocompatibility evaluation of reconstruction of traumatic defect of rabbit urethra using extracellular matrix.

OBJECTIVE: To investigate the curative effect and histocompatibility of reconstruction of traumatic urethral defect of rabbit using urethral extracellular matrix (ECM). METHODS: Urethral ECM was obtained by excision of the urethra in 20 donor rabbits. In experimental group, 20 rabbits were resected a 1.0 cm-1.5 cm segment of the urethra and artificially made a model of traumatic urethral defect, then reconstructed by the urethral extracellular matrix of the same length. The rabbit immunity response was assessed by lymphocyte transformation test and serum TNF-alpha level. The reconstructed urethral segments were stained with hematoxylin-eosin and Van Gieson stain and observed by histological examination postoperatively. The urethrography, urethroscopy and urodynamic examinations were performed. RESULTS: There was no significant difference in stimulative index of lymphocyte transformation between ECM group and control group. The serum TNF-alpha levels of ECM group slightly rose, but the increase was not significant as compared with control group. On postoperative day 10, epithelial cell had migrated from each side and small vessels were found in the extracellular matrix. In the 3rd week, several layers of urothelium covered the whole surface of the matrix tube. In the 6th week, the disorganized arrangements of smooth muscle fibers were firstly observed by Van Gieson staining. In the 24th week, the smooth muscle cells increased and the matrix tube appeared fairly similar to normal urethral wall components. The urethroscopy and urodynamic evaluation revealed that the surface of reconstructed urethra was smooth and emiction was unobstructed. CONCLUSION: The urethral extracellular matrix might be an ideal and safe biomaterial for the reconstruction of urethral traumatic defect.

Reconstruction of rabbit urethra using urethral extracellular matrix.

BACKGROUND: Urethral reconstruction for both congenital and acquired etiologies remains a challenge for most urologic surgeons. Tissue engineering has been proposed as a strategy for urethral reconstruction. The purpose of this study was to determine whether a naturally derived extracellular matrix substitute developed for urethral reconstruction would be suitable for urethral repair in an animal model. METHODS: A urethral segmental defect was created in 20 male rabbits. The urethral extracellular matrix, obtained and processed from rabbit urethral tissue, was trimmed and transplanted to repair the urethral defect. Then, the regenerated segment was studied histologically by haematoxylin-eosin staining and Van Gieson staining at 10 days, 3 weeks, 6 weeks, and 24 weeks postoperation. Retrograde urethrography was used to evaluate the function of the regenerated urethras of 4 rabbits 10 and 24 weeks after the operation. The urodynamics of 4 rabbits from the experimental group and control group I were assessed and compared. In addition, 4 experimental group rabbits were examined by a urethroscope 24 weeks after the operation. RESULTS: At 10 days after operation, epithelial cells had migrated from each side, and small vessels were observed in the extracellular matrix. The matrix and adjacent areas of the host tissue were infiltrated with inflammatory cells. The epithelium covered the extracellular matrix fully at 3 weeks postoperation. Well-formed smooth-muscle cells were first confirmed after 6 weeks, at which point the inflammatory cells had disappeared. At 24 weeks postoperation, the regenerated tissue was equivalent to the normal urethra. Urethrography and urodynamic evaluations showed that there was no difference between normal tissue and regenerated tissue. CONCLUSIONS: Urethral extracellular matrix appears to be a useful material for urethral repair in rabbits. The matrix can be processed easily and has good characteristics for tissue handling and urethral function.