[Glomuvenous malformation: a clinicopathological analysis of 31 cases].

Objective: To investigate the clinicopathological features of glomuvenous malformation (GVM). Methods: Thirty-one cases of GVM diagnosed at the Henan Provincial People's Hospital from January 2011 to December 2021 were collected. Their clinical and pathological features were analyzed. The expression of relevant markers was examined using immunohistochemistry. The patients were also followed up. Results: There were 16 males and 15 females in this study, with an average age of 11 years (range, 1-52 years). The locations of the disease included 13 cases in the limbs (8 cases in the upper limbs, 5 cases in the lower limbs), 9 cases in the trunks, and 9 cases in the foot (toes or subungual area). Twenty-seven of the cases were solitary and 4 were multifocal. The lesions were characterized by blue-purple papules or plaques on the skin surface, which grew slowly. The lumps became larger and appeared to be conspicuous. Microscopically, GVM mainly involved the dermis and subcutaneous tissue, with an overall ill-defined border. There were scattered or clustered irregular dilated vein-like lumens, with thin walls and various sizes. A single or multiple layers of relatively uniform cubic/glomus cells were present at the abnormal wall, with scattered small nests of the glomus cells. The endothelial cells in the wall of abnormal lumen were flat or absent. Immunohistochemistry showed that glomus cells strongly expressed SMA, h-caldesmon, and collagen IV. Malformed vascular endothelial cells expressed CD31, CD34 and ERG. No postoperative recurrence was found in the 12 cases. Conclusions: GVM is an uncommon type of simple venous malformation in the superficial soft tissue and different from the classical glomus tumor. Morphologically, one or more layers of glomus cells grow around the dilated venous malformation-like lumen, which can be combined with common venous malformations.

[Clinicopathologic analysis of micronodular thymoma with lymphoid stroma].

Objective: To investigate the clinicopathologic features of micronodular thymoma with lymphoid stroma(MNT). Methods: Five cases of MNT diagnosed from January 2007 to December 2016 in Henan Provincial People's Hospital were collected.Hematoxylin-Eosin staining and immunohistochemistry were used to evaluate the histological and immunophenotypic characteristics in 5 MNT cases. Epstein-Barr virus (EBV) status was detected by in situ hybridization for EBV-encoded small RNA (EBER). Polymerase chain reaction was used to detect the rearrangement of immunoglobulin genes. Results: Five cases were MNT, including 3 male and 2 female patients, mean aged 59 years (from 43 to 63 years). All patients had ananterior mediastinal mass, with no myasthenia gravis and autoimmune diseases, and underwent surgical resection.Half to ten years follow-up showed no recurrence.Grossly, the tumors were solid in 4 cases, and cystic and solid in 1 case; the border was clear. Histologically, the tumors presented as a distribution of micronodules separated by abundant lymphoid stroma with prominent germinal centers. The nodules were composed of neoplastic spindle, oval cells containing bland, oval nuclei.Immunohistochemical study showed strong positivity of the tumor cells for CKpan, CK19, CK5/6 and p63. Stains for EMA, CD117, calretinin, TTF1 were negative in the tumor cells.Scattered CD3, CD1a, and TdT positive immature T lymphocytes were noted in and around tumor nodules. Many lymphocytes in the stroma, including germinal centers, were positive for CD20.The bcl-2 was also detected in lymphocytes in the stroma, mantle and marginal zone of lymphoid follicles, and in part of tumor cells. Tumor cells and lymphocytes were negative for EBER. Immunoglobulin genes rearrangement analysis showed that B lymphocytes were polyclonal. Conclusions: MNT is a rare thymoma, which occurs in the elderly and has no obvious symptom. After complete resection, the prognosis is very good. The diagnosis should be based on a combination of clinicopathologic features, and other types of thymoma should be excluded.

[The early changes of respiratory system resistance and γδT lymphocytes infiltrated in graft after lung transplantation of mouse].

Objectives: To generate an orthotopic left lung transplantation model in mice, and to observe the early changes of respiratory system resistance and γδT lymphocytes infiltrated in grafts. Methods: The research time was from March 2014 to May 2015. The male C57BL/6 mice (n=35) and BALB/c mice (syngenic group, n=10) were randomly divided into five groups. Control group (n=5): wild C57BL/6 mice; syngenic transplant group (n=10): C57BL/6→C57BL/6; allogenic transplant group(allogenic group, n=10): BALB/c→C57BL/6; each transplant group was randomly divided into 3-day and 7-day subgroups (n=5). Respiratory system resistance and histological features of grafts were assessed, and differences in graft infiltrating γδT lymphocytes and mRNA expression of interleukin (IL)-17A were quantified on 3 and 7 days after transplantation. Multiple comparisons were performed using one-way analysis of variance and least significant difference analysis. Results: (1) The respiratory system resistance of syngenic group and allogenic group were (2.61±0.59) cmH2O·s/ml and (2.84±0.31) cmH2O·s/ml 3 days post-operation, both of them increased compared to control group (1.39±0.17) cmH2O·s/ml (1 cmH2O=0.098 kPa) (P=0.001, 0.000). The respiratory system resistance of allogenic group were (4.33±0.67) cmH2O·s/ml 7 days post-operation, which was significantly higher than that of syngenic 7-day subgroup (1.87±0.27) cmH2O·s/ml and control group (1.39±0.17) cmH2O·s/ml (P=0.000, 0.000). (2) The isografts of syngenic group showed a relatively normal histological appearance with minimal infiltration of inflammatory cells, and the allografts of allogenic group infiltrated apparently by inflammatory cells, especially 7-day subgroup showed acute cellular rejection. (3) The percentage of γδT lymphocytes infiltrated in isografts and allografts were 3.90%±0.86% and 4.40%±0.57%, respectively, which were significantly increased compared to that of control lungs 2.00%±0.23% 3 days post-operation(P=0.000, 0.000); The percentage of γδT lymphocytes infiltrated in 7 days allografts was 5.40%±0.98% , which was higher compared to that of 7 days isografts 2.60%±0.54% and control lungs 2.00%±0.23% (P=0.000, 0.000). (4) IL-17A mRNA expression levels were 3.37±0.55 and 5.23±1.50 in isografts and 6.77±0.93 and 27.32±4.20 in allografts, on postoperative day 3 and 7 respectively. All of them were significantly upregulated compared to that of control lungs 0.99±0.08 (P=0.000, 0.000), and allografts exhibited significantly greater IL-17A transcript levels compared to isografts on postoperative day 3 and 7 (P=0.000, 0.000). Conclusion: The rise of respiratory system resistance of lung grafts after transplantation may relate to the increased IL-17A-producing γδT lymphocytes infiltrated in the grafts.

Sex identification based on AMEL gene PCR amplification from blue sheep (Pseudois nayaur) fecal DNA samples.

The use of noninvasive genetic sampling to identify the sex of wild animals is an extremely valuable and important tool in molecular ecology and wildlife conservation. Sex determination using the amelogenin gene has been conducted in many species because only a single pair of primers is required to amplify both X- and Y-linked alleles. However, this method has not been used in field research with the feces of wildlife. In this study, we applied this method to 222 fecal samples from wild blue sheep (Pseudois nayaur) using amelogenin primers (SE47/SE48) after testing the effectiveness of sex determination using tissue samples and fecal samples from blue sheep of known sex. We found this method to be highly reliable (80.2%) for blue sheep. Amelogenin can be used to identify the sex of wild animals using fecal samples.

Direct comparison of the dynamics of IL-25- and 'allergen'-induced airways inflammation, remodelling and hypersensitivity in a murine asthma model.

BACKGROUND: Interleukin-25 has been implicated in the pathogenesis of asthma from studies on human asthmatics and in murine asthma models. OBJECTIVES: In this study, we hypothesized that chronic exposure of the airways to IL-25 alone is able to induce pathogenic changes observed in animal models of asthma. METHODS: We performed a detailed comparison of the dynamics of development of cellular infiltration, cytokine expression and airways remodelling and hyperresponsiveness in mice sensitized and challenged with OVA, a classical model of allergic asthma and those exposed to IL-25 alone. RESULTS: Intranasal challenge of BALB/c mice with IL-25 alone induced a delayed (compared with OVA-challenge), predominantly eosinophilic and lymphocytic infiltration into the airways lumen, along with increased production of Th2-type cytokines, chemokines and collagen, secretion of epithelial mucus, goblet cell hyperplasia, deposition of subepithelial collagen, airways smooth muscle cell hyperplasia and angiogenesis. Correspondingly, IL-25 as well as OVA challenge both induced airways hyperresponsiveness and increased lung tissue damping. In contrast, IL-25 exposure did not increase IgE or IgG1 production. CONCLUSIONS AND CLINICAL RELEVANCE: The data suggest that chronic airways exposure to IL-25 alone is sufficient to induce allergen- and IgE-independent, asthma-like airways inflammation, remodelling and hyperresponsiveness in mice. Thus, IL-25 is a key molecular target in asthma, irrespective of the coexistence of IgE-dependent mechanisms.

Apparent diffusion coefficient measurements of bilateral kidneys at 3 T MRI: effects of age, gender, and laterality in healthy adults.

AIM: To investigate the effects of age and gender on apparent diffusion coefficient (ADC) measurements of bilateral kidneys at 3 T MRI, and compare the ADC values of left and right kidneys. MATERIALS AND METHODS: In all, 137 healthy participants (mean age 42.8 ± 14.7 years; age range 16-75 years) comprising 68 male and 69 female participants were enrolled. Three Tesla echo-planar diffusion-weighted imaging (DWI) of bilateral kidneys was performed and ADC values were measured in the cortex, medulla, and whole parenchyma. Pearson correlation analysis and linear regression were performed to determine the associations between the ADC values in each region and age. Effects of age and gender on ADC values were analysed using two-factor analysis of variance (ANOVA). The paired-samples t-test was established to compare the ADC values between left and right kidneys. RESULTS: ADC values were significantly higher in the young group (≤50 years) than in the old group (>50 years), and correlated inversely with the age in all regions. Male participants had higher ADC values than female participants in all regions except left medulla. Two-factor ANOVA of age × gender showed no significant interactions between the variables age and gender were found. No significant differences in ADC values between left and right kidneys were observed. CONCLUSION: Renal ADC values are age- and gender-dependent, and show no significant difference between left and right kidneys. Age- and gender-related effects should be taken into consideration in future renal DWI studies when using normal ADC values from health controls.

[Abdominal function and appearance of patients after repairing the extensive skin and soft tissue defects in the limbs with two types of lower abdominal tissue flaps].

Objective: To study the abdominal function and appearance of patients after repairing the extensive skin and soft tissue defects in the limbs with two types of lower abdominal tissue flaps. Methods: A retrospective clinical controlled study was conducted. From June 2016 to October 2022, 17 patients with extensive skin and soft tissue defects in the limbs who met the inclusion criteria were admitted to the Department of Bone Hand Microsurgery of Shandong Wendeng Orthopedic Hospital, including 2 males and 15 females, aged 21-60 years, with a defect ranging from 15.0 cm×10.0 cm to 23.0 cm×15.0 cm. According to the applied repair method, the patients were divided into deep inferior epigastric perforator (DIEP) flap group (9 cases) with the defect wound being repaired by the DIEP flap and muscle sparing transverse rectus abdominis myocutaneous (MS-TRAM) flap group (8 cases) with the defect wound being repaired by the MS-TRAM flap. On post surgery day (PSD) 1, 3, 5, 7, and 14, the blood supply of the tissue flaps was evaluated using a self-made tissue flap blood supply evaluation scale. At 12 months after surgery, the patients' satisfaction with the efficacy of tissue flap repair was evaluated using the satisfaction score standard for flap efficacy. Before surgery and at 3 and 12 months after surgery, a self-made abdominal wall strength evaluation scale was used to evaluate the strength of abdominal wall. At 12 months after surgery, a self-made abdominal appearance evaluation scale was used to evaluate the condition of abdominal scars, degree of abdominal symmetry, the appearance and restoration of umbilicus, abdominal protrusion during dressing, and formation of folds on both sides of the abdomen. Data were statistically analyzed with analysis of variance for repeated measurement, independent sample t test, paired sample t test, and Fisher's exact probability test. Results: On PSD 1, 3, 5, 7, and 14, there was no significant change in the blood supply score of tissue flaps of patients in the two groups, and there was no statistically significant difference between the two groups (P>0.05). At 12 months after surgery, the satisfaction ratio of patients in DIEP flap group with tissue flap repair efficacy was 8/9, which was close to 7/8 in MS-TRAM flap group (P>0.05). The preoperative abdominal wall strength of patients between the two groups was similar (P>0.05), while the abdominal wall strength of patients in DIEP flap group was significantly stronger than that in MS-TRAM flap group at 3 and 12 months after surgery (with t values of 3.09 and 3.02, respectively, P<0.05). Compared with the preoperative strength within each group, the abdominal wall strength of patients in DIEP flap group at 3 months after surgery and in MS-TRAM flap group at 3 and 12 months after surgery decreased significantly (with t values of 6.04, 9.71, and 2.91, respectively, P<0.05), which did not change significantly in DIEP flap group at 12 months after surgery (P>0.05). At 12 months after surgery, the scores of abdominal scars, degree of abdominal symmetry, the appearance and restoration of umbilicus, abdominal protrusion during dressing, and formation of folds on both sides of the abdomen of patients were similar between the two groups (P>0.05). Conclusions: Free transplantation of DIEP flap and MS-TRAM flap to repair the extensive skin and soft tissue defects in the limbs can achieve good repair results, including good blood supply of tissue flap and abdominal shape, and the patients' high degree of satisfaction with the efficacy of tissue flap repair. However, DIEP flap is superior to MS-TRAM flap in terms of long-term postoperative abdominal wall strength recovery, showing a broader prospect of application.

Red wine inhibits monocyte chemotactic protein-1 expression and modestly reduces neointimal hyperplasia after balloon injury in cholesterol-Fed rabbits.

BACKGROUND: Wine consumption decreases the risk of myocardial infarction. Intimal hyperplasia contributes to restenosis after angioplasty. Local ethanol delivery inhibits intimal hyperplasia after balloon injury in rabbit iliac and pig coronary arteries. The effects of wine consumption on intimal response and monocyte chemotactic protein-1 (MCP-1) expression were studied in cholesterol-fed rabbits. METHODS AND RESULTS: Male rabbits were fed a 2% cholesterol diet together with red wine (12.5% vol, 5 mL/kg body wt per day; n=7), white wine (13.3% vol, 5 mL/kg body wt per day; n=7), or no wine as a control (n=8) for 6 weeks. A balloon injury of the abdominal aorta was performed at the end of the third week. Abdominal aortas were harvested at the end of 6 weeks. Neointimal hyperplasia was measured morphometrically. MCP-1 expression was determined by Northern blot, in situ hybridization, and immunohistochemistry. Rabbits fed red wine had significantly less neointimal hyperplasia than did control rabbits (intima/media area ratio 0.59+/-0.05 [red wine group] versus 0.79+/-0.07 [control group], P<0.05). However, rabbits fed white wine showed a trend (but not significant) toward less intimal response compared with control rabbits (intima/media area ratio 0.65+/-0.04 [white wine group] versus 0.79+/-0.07 [control group], P=0.165). Both red wine and white wine significantly reduced MCP-1 mRNA and protein expression in the aorta. CONCLUSIONS: Long-term consumption of red wine and white wine inhibits MCP-1 expression, and in the small number of animals studied, red wine modestly reduces neointimal hyperplasia. Since red wine exhibits higher antioxidant capacity than does white wine, the decreased intimal response might be partly attributed to its antioxidant effects.

Bioconcentration, elimination and metabolism of 2,4-dinitrotoluene in carps(Cyprinus Carpio L.).

Bioconcentration curves of 2,4-dinitrotoluene(2,4-DNT) in carps (whole fish, liver, intestine and muscle) were investigated using semistatic system. For whole fish, its curve could be described as a gentle peak which began with a rise in concentration to summit or steady state, then declined and reached lower level followed by another steady state. For liver and intestine, their curves both contained two successive peaks, with the second peak followed by slight fluctuation. Bioconcentration factors of 2,4-DNT in whole fish during the first and second steady state were 9.15 and 4.15,(97.86 and 44.39, based on lipid content), respectively. By logarithmic plotting, two straight-lines with different slopes(3.6 and 0.1 d-1) were measured for elimination. According to peaky curves of 2,4-DNT in whole fish, liver and intestine, smaller BCFs than calculated BCFs based on the regression equations for inert chemicals, and large rate constants of elimination, biotransformation was inferred to have happened in tissues such as liver, intestine, and other tissues. Two metabolites were separated from liver and identified as 4-amino-2-nitrotoluene(4A2NT) and 2,4-diamino-toluene(2,4-DAT) on HPLC, their retention times were 23.1 and 8.8 min, respectively. In bioconcentration test of 2,4-DNT in liver, two metabolites and parent were determined at the same time at intervals, higher concentrations of 4A2NT and 2,4-DAT were found when level of 2,4-DNT declined. Such results demonstrated our inference that metabolism caused the declines in bioconcentration curves. A one-compartment model was set up to simulate the bioconcentration, in which biotransformation adhered to Delayed Enzyme-Catalytic Logarithmic Kinetics. Good fit of model curves with measured values could be observed.

[Antibodies to Klebsiella pneumoniae in ankylosing spondylitis].

This study was performed to evaluate the involvement of Klebsiella pneumoniae (Kp) in ankylosing spondylitis. Serum IgA, IgG and IgM antibodies to Kp were measured with ELISA in 60 patients with ankylosing spondylitis (AS), 28 patients with rheumatoid arthritis (RA) and 45 healthy individuals. A marked elevation of IgA antibody to Kp was detected in the sera of patients with AS, compared to that in patients with RA (P < 0.02) and healthy controls (P < 0.001). The positive rate of antibodies to Kp was 55% in patients with active AS, significantly higher than that in patients with inactive AS (16.7%, P < 0.01), patients with RA (17.8%, P < 0.05) and healthy controls (4.4%, P < 0.001). Stool culture for Kp was carried out in 15 of the 60 patients with AS simultaneously, 3 (20%) of them were positive. Our results are in line with the previously published findings suggesting that Kp may play a role in the pathogenesis of AS.

[Serum anti-polytene chromosomes of Drosophila melanogaster antibody (AchrA) and systemic lupus erythematosus].

The determination of serum AchrA in patients with SLE(43) and other rheumatic diseases (ODRs, 109) and in 42 normal individuals was measured by indirect immunofluorescence assay (IIF) using the polytene chromosomes of the third instar larva of Drosophila melanogaster as the substrate. The results showed that the serum AchrA was negative in all of the 42 normal individuals and the 109 patients with ORDs and the AchrA was positive in 19 (44%) of the patients with SLE. The patients with active SLE were found in 16 (84%) of the 19 AchrA positive group and 13 (54%) of the 24 AchrA negative group. The incidence of arthritis/arthralgia, photosensitivity, glomerulonephritis and anemia in the SLE patients were higher in the AchrA positive group than those in the AchrA negative group. In contrast, the patients with nephrotic syndrome were more common in the AchrA negative group than in the AchrA positive group. It is suggested that serum AchrA is extremely specific and more sensitive for SLE and that the finding of positive AchrA are usually associated with activity of SLE and renal involvement.

Expression of human beta E-globin gene with erythroid enhancer in transgenic mice.

The human beta E-globin gene from HbE (beta 26 Glu-->Lys, G-->A) homozygote, a common hemoglobinopathy in China, was injected into the pronuclei of fertilized mouse eggs to prepare transgenic mice. A transgenic mouse bearing 16 copies of construct 5'.HS2 beta E has characteristics of typical transgenic mice. It has been verified that the presence of erythroid enhancer 5'HS2 is necessary for the high level expression of human beta E-globin gene in transgenic mice, indicating that the cis-element 5'HS2 is effective for abnormal beta-globin gene as well. Although the expression level of beta-globin gene was copy number-dependent as reported in previous studies, the average expression level per gene copy (12.1%) in transgenic mice bearing many copies of 5'HS2 beta E (16 copies) was significantly lower than that (79.7%) in transgenic mice bearing fewer copies of the gene (2 copies). The possible mechanisms for this decrease of expression are discussed. Novel hemoglobin tetramers which presumably consist of human beta E-globin chains and mouse endogenous alpha-globin chains have been assembled in transgenic mice.

Effects of hyperlipidemia on aortic endothelial cell turnover and transendothelial macromolecular transport in cholesterol-fed rats.

BACKGROUND: Hyperlipidemia, hypertension, cigarette smoking and diabetes are some major risk factors for atherosclerosis and cardiovascular disease. Repeated endothelial injury and enhanced focal intimal influx of plasma lipoproteins are the pivotal mechanisms involved in atherogenesis. We previously demonstrated that the endothelial cell turnover and associated endothelial permeability were significantly increased in the aorta of spontaneously hypertensive rats, chronic oral nicotine-treated rats, and streptozotocin-diabetic rats. In the present investigation, we examined the effects of hyperlipidemia on arterial endothelial cell turnover and transendothelial macromolecular transport in cholesterol-fed rats. METHODS: Sixteen male Sprague-Dawley rats were fed a diet containing 5% cholesterol for 6 weeks. A group of 14 agematched rats fed a regular diet and maintained over the same time period, were served as the controls. In en face preparations of the thoracic aorta, mitotic endothelial cells were identified by hematoxylin staining, IgG-containing dead endothelial cells were identified by an indirect immunoperoxidase method, and endothelial leakage to Evans blue-albumin complexes was quantified by fluorescence microscopy. RESULTS: The results showed that plasma cholesterol and triglyceride levels were higher in cholesterol-fed rats. The hyperlipidemic rats, compared to control rats, had higher values for the frequency of endothelial cell death (1.08 +/- 0.28% vs 0.75 +/- 0.16%), the frequency of endothelial cell mitosis (0.015 +/- 0.005% vs 0.013 +/- 0.003%) and the number density of Evans blue-albumin leaky foci (6.19 +/- 0.64/mm2 vs 5.23 +/- 0.76/mm2) in the aorta. CONCLUSIONS: Similar to the situations in hypertension, nicotine consumption and diabetes, the observed trend of increases in the frequency of endothelial cell turnover and endothelial permeability to large molecules in the aorta of cholesterol-fed rats suggested that these changes may contribute to accelerated atherogenesis in hyperlipidemia. However, since rat is not a favored animal model for studies of dietinduced hyperlipidemia and atherosclerosis, further investigations using other animal models such as rabbit, are needed to verify these observations.

Biological monitoring of deltamethrin in sprayers by HPLC method.

Using HPLC, the authors had investigated the three metabolites of deltamethrin (DM) in the urine of spraymen and one suicide, namely: dibromovinyl-dimethylcyclopropane carboxylic acid (Br2A), 3-phenoxybenzyl-hydroxy-ethyl acetate (PHE) and 3-phenoxyl-benzoic acid (BA). Br2A was chosen as the biological monitoring parameter for DM exposed people, and the urine samples of one suicide and 11 farmers sprayed DM or DM plus methamidophos were examined for Br2A quantitatively which was detected in 8 of 11 sprayers and in the suicide case.

Two monoclonal antibody lines directed against subunit IV of cytochrome oxidase: a study of opposite effects.

Two monoclonal lines of antibodies were isolated with specificities against the amino half of Subunit IV of beef heart cytochrome oxidase. The lines had nonoverlapping epitopes. Both bound to the matrix face of membranous oxidase, neither bound to the cytoplasmic face. One line (QA4/C4) stimulated electron transfer in soluble or membranous oxidase, while the other (QA4) inhibited that activity by both oxidase preparations. These effects on electron transfer activity were not altered by the inclusion or omission of detergent. ATP depressed the binding of either antibody to either soluble or membranous oxidase. In the absence of ATP, QA4/C4 stimulated electron transfer only in the high affinity phase of cytochrome c oxidation (with decreased KM and increased Vmax), causing slight inhibition in the low affinity phase (with decreased KM). In the presence of ATP, QA4/C4 abolished the high affinity phase, but did not alter the ATP influence on the low affinity phase. In the absence of ATP, antibodies of line QA4 abolished the low affinity phase, leaving a high affinity phase similar to that induced by ATP. In the presence of ATP, QA4 abolished the high affinity phase, leaving a low affinity phase similar to that seen with ATP alone. This behavior is consistent with the dissection of two catalytic sites for cytochrome c and more than one ATP affector site.

Role of endothelial cell mitosis in transendothelial transport of low density lipoprotein in hypercholesterolemic and normal rabbits.

BACKGROUND: Atherosclerosis is characterized by focal areas of lipid accumulation and intimal smooth muscle cell proliferation in large arteries. It has been suggested that the permeability of arterial endothelium to lipid is an important factor in the initiation and progression of atherosclerosis. The mechanism by which macromolecules such as low density lipoprotein (LDL) enter the arterial wall, however, is still not completely understood. Our previous studies have demonstrated that there is close association of endothelial cell turnover with transendothelial macromolecular transport in normal rat aorta. Because hypercholesterolemia has been well documented as one of the major risk factors for atherosclerosis, we explore the relationship between endothelial cell mitosis and transendothelial transport of LDL in hypercholesterolemic rabbits. METHODS: The present study is designed to perform on thoracic aortae from 30 male New Zealand white rabbits fed with either 1% cholesterol-enriched diet (HC group; n = 15) or normal diet (NC group; n = 15). The concentrations of serum cholesterol and triglycerides from two groups were measured by enzymatic procedures using commercial kits. The aortae of hypercholesterolemic and normocholesterolemic rabbits underwent perfusion-fixation 10 min following the intravenous injection of low density lipoprotein conjugated with Lucifer yellow (LY-LDL) for fluorescence microscopy. En face preparations of the thoracic aortae stained with hematoxylin allowed the identification of ECs in mitosis. The relationship between LY-LDL leakage and endothelial cell mitosis was determined. RESULTS: Although endothelial cell mitosis is infrequent (NC: 0.0022 +/- 0.0007%; HC: 0.0004 +/- 0.0001%) in the thoracic aorta of New Zealand white rabbits, 68.2 +/- 8.4% (NC) or 74.3 +/- 9.0% (HC) of dividing cells in the M phase were associated with LYLDL leakage. These dividing cells accounted for 65.0 +/- 9.2% (NC) or 64.4 +/- 11.3% (HC) of all LY-LDL leaky spots. CONCLUSIONS: Thus, this study not only confirmed the close association of EC mitosis with macromolecular permeability in normal group, but also demonstrated that the same relationship existed in hypercholesterolemic rabbits. These observations lend support to the theory that transiently open junctions surrounding the endothelial cells undergoing cell turnover provide pathways through which LDL enters the subendothelial space, resulting in lipid accumulation and atherosclerosis.