[Differentiation of temporal lobe epilepsy and temporal plus epilepsy using radiomics nomogram based on MPRAGE images].

A total of 82 patients with temporal lobe epilepsy (TLE) and temporal plus epilepsy (TPE)admitted in Xuanwu Hospital from January 1, 2019, to January 1, 2021 were restrospectively analyzed, including 41 males and 41 females, aged 2 to 52 (24±10) years. The patients were randomly divided into the training set (58 cases) and test set (24 cases) by Python. FreeSurfer software was used to segment the cortex of the affected hemisphere, defining 33 regions of interest (ROIs), and radiomics features were extracted by Python. After selecting features using the filter-based feature selection method, a radiomics model was constructed with a logistic regression classifier, and radiomics scores were calculated. Combining clinical characteristics with radiomics scores, a nomogram model was constructed using R software, the predictive accuracy of the model was assessed with the concordance index (C-index), and the model's goodness-of-fit was tested with the Hosmer-Lemeshow method. The results showed statistically significant differences between TLE and TPE patients in disease duration, intracranial electrode implantation, and hippocampal sclerosis (both P<0.05). The accuracy of the radiomics model in the training set and the test set was 91.4% and 87.5%, respectively. The nomogram model uses C-index to predict accuracy. Hosmer-Lemeshow method was used to test the goodness of fit, with AUCs of 0.95 (95%CI: 0.853-0.991) in the training set and 0.84 (95%CI: 0.676-0.999) in the test set. The study indicates that the radiomics nomogram model based on MPRAGE sequences can effectively differentiate TLE from TPE, providing reference for the development of personalized treatment plans in clinical practice.

[The prevalence of HIV, hepatitis C virus and syphilis and related factors among cross-border couples in Mangshi county, Dehong Dai and Jingpo Autonomous Prefecture of Yunnan province from 2017 to 2019].

Objective: To understand the prevalence of HIV, hepatitis C virus (HCV) and syphilis and related factors among cross-border couples in Mangshi county, Dehong autonomous prefecture, Yunnan province. Methods: From May, 2017 to April, 2019, 2 500 couples with 5 000 cross-border marriages were selected by using cluster sampling method. The demographic characteristics, AIDS-related health services, HIV, HCV, syphilis infection and other information were collected through questionnaires and laboratory tests. The influencing factors of HIV, HCV and syphilis infection were analyzed by multivariate logistic regression model. Results: A total of 2 500 couples with cross-border marriage were investigated, among which 2 438 (97.5%) couples were Chinese men with Myanmar women. The average age of 5 000 participants was (34.16±9.00) years. Most of them were minority groups (59.9%), farmers (98.5%), education years ≤6 years (81.4%), marriage years>3 years (80.0%), and from mountainous areas (61.7%). The HIV prevalence of Chinese and Myanmar populations was 1.7% (43/2 500) and 2.0% (49/2 500), respectively. The HCV infection rates were 2.0% (49/2 500) and 1.3% (32/2 500), respectively and the infection rates of syphilis were 0.4% (10/2 500) and 0.2% (4/2 500), respectively. There were no statistically significant differences in the prevalence of three diseases among Chinese and Myanmar populations (P>0.05). The multivariate analysis showed that compared with those aged ≤ 30 years, having lower AIDS awareness, never receiving HIV testing, without HCV and syphilis infection, HIV prevalence was higher among those aged>30 years (OR=3.21, 95%CI: 1.80-5.73), having higher AIDS awareness (OR=17.41, 95%CI: 4.27-70.91), receiving HIV testing (OR=4.93, 95%CI: 2.72-8.92), with HCV infection (OR=5.64, 95%CI: 2.72-11.70) and syphilis infection (OR=8.37, 95%CI: 1.63-43.08). Compared with those aged ≤ 30 years, having marriage years ≤ 3 years, and with HIV negatives, HCV infection rate was higher among those age>30 years (OR=3.02, 95%CI: 1.69-5.38), having marriage years>3 years (OR=2.24, 95%CI: 1.34-3.74), and with HIV positives (OR=6.69, 95%CI: 3.29-13.59). Compared with those having HIV negatives, the syphilis infection rate was relatively higher among participants with HIV positives (OR=9.07, 95%CI: 2.00-41.10). Conclusion: The prevalence of HIV, HCV, and syphilis among cross-border couples in Mangshi county, Dehong autonomous prefecture of Yunnan province is relatively high. Age, AIDS awareness, HIV testing history, and the length of marriage are associated with the HIV, HCV, and syphilis infection.

[Early mortality and risk analysis in adult patients with maintenance hemodialysis].

Objective: To retrospectively analyze the early mortality and related risk factors in adult patients with maintenance hemodialysis (MHD). Methods: Adult MHD patients from 2008 to 2018 were enrolled and divided into training data group and validation data group. In training data group, multivariate logistic regression was used to analyze the risk factors of early death within 120 days after hemodialysis and establish a prediction model. The receiver operating characteristic (ROC) curve was applied to evaluate the prediction ability of the model. Results: A total of 4 885 patients were included. The cumulative mortality within 120 days was 20.97/100 person years, and that within 365 days was 12.25/100 person years. A total of 3 603 patients in the training data group were analyzed. The following risk factors were correlated with early mortality (all P<0.05), including age at start of dialysis over 60 years old (OR=1.792), non-chronic glomerulonephritis (OR=2.214), cardio-cerebrovascular disease (OR=2.695), plasma albumin less than 35 g/L (OR=1.358), platelet count less than 120×109/L (OR=2.194), serum creatinine less than 600 µmol/L (OR=1.652), blood urea nitrogen over 30 mmol/L (OR=1.887), blood phosphorus less than 1.13 mmol/L (OR=1.783), pulse pressure over 55 mmHg(1 mmHg=0.133 kPa) (OR=1.656), low density lipoprotein less than 1.5 mmol/L (OR=1.873), and blood calcium over 2.5 mmol/L (OR=1.876). Risk prediction model was established. The other 1 282 cases in the validation data group were verified. The area under ROC curve was 0.810, with sensitivity 85.7%, and specificity 62.5%. Conclusion: The mortality rate of adult MHD patients within 120 days after dialysis is high. The established prediction model can effectively predict the risk of early death.

Antioxidant and Hypoglycemic Activities of Exopolysaccharide by Submerged Culture of Inocutus Hispidus.

This work was to investigate the hypoglycemic and antioxidant activities of the exopolysaccharides produced in a stirred-tank bioreactor by Inocutus hispidus. The exopolysaccharides showed significant antioxidant activities, up to 70.7±2.5% inhibition of hydroxyl radicals, 50% inhibition of 2,2-diphenyl-1-picrylhydrazyl radicals, and a Trolox equivalent antioxidant capacity of 3.3 mM. The exopolysaccharide also showed notable hypoglycemic effects in streptozotocin-induced diabetic mice, reducing the plasma glucose, total cholesterol and triacylglycerol concentrations by 18.2±1.5, 20.9±0.8 and 14.4±0.4, respectively. The results demonstrated the potential of this EPS for human health protection against oxidative damage and hyperglycemia.

Effect of chemoradiotherapy and neoadjuvant chemoradiotherapy in resectable pancreatic cancer: a systematic review and meta-analysis.

OBJECTIVE: Controversy remains existed whether chemoradiotherapy (CRT), especially neoadjuvant chemoradiotherapy (neoadjuvant CRT) achieves a significant benefit in resectable pancreatic cancer (PC) treatment. In this meta-analysis, we aimed to clarify the benefits of CRT and neoadjuvant CRT in resectable PC. METHODS: Eligible trials were identified from MEDLINE, EMBASE, Cochrane center, China National Knowledge Internet and Wanfang database since their inception to July 31, 2013. Only patients with resectable PC, who underwent tumor resection and received CRT and/or neoadjuvant CRT, were enrolled. The treatment outcomes were overall survival (OS) and progression-free survival (PFS). Hazard ratio (HR) with a 95% confidence interval (CI) was used to measure the pooled effect according to a fixed-effects model. The statistical heterogeneity between trials was detected by χ(2) and I (2) test. Sensitivity analyses were also carried out. RESULTS: A total of 28 studies were identified as relevant, but only 17 studies with a total of 3,088 patients were included in the comparison between CRT versus non-CRT, and a total number of three studies with 189 patients included in the comparison between neoadjuvant CRT versus postoperative CRT. The comparison between CRT and non-CRT showed that the overall pooled HR for death was 0.96 (95% CI 0.89-1.03; P = 0.28). The HR for progress was 0.83 (95% CI 0.68-1.03, P = 0.09). Comparison between neoadjuvant CRT and adjuvant CRT revealed a pooled HR of 0.93 (95% CI 0.69-1.25; P = 0.62). CONCLUSIONS: This meta-analysis showed that CRT showed no significant effect on OS and PFS when compared to non-CRT. Neoadjuvant CRT showed no significant effect over postoperative adjuvant CRT.

Impact of clinical condition at restarting dialysis on outcome after kidney allograft loss: a single-center experience.

BACKGROUND: The purpose of this paper was to determine the impact of the clinical condition of the patient at the restart of dialysis on long-term survival after renal graft loss. METHODS: We performed an analysis of 110 patients with renal allograft failure compared with 115 hemodialysis patients without kidney transplantation. RESULTS: There was a relatively high glomerular filtration rate, low serum albumin, and greater prevalence of infection among graft loss patients compared with the never-transplanted patients. Patient survival after allograft loss was significantly lower than that of never-transplanted patients (P = .024) with 63.4% patients succumbing in the first 3 months. Serum hepatitis B virus (HBV) positivity, cardiovascular disease (CVD) and malnutrition were independent risk factors for graft loss patient upon COX regression analysis. CONCLUSIONS: Serum HBV positive, complicated with CVD and malnutrition were independent risk factors for the graft loss among patients who restarted hemodialysis. More attention should be paid to treat complications of transplant recipients in K/DOQI 4 and 5 stages.

Glioblastoma stem cells produce vascular endothelial growth factor by activation of a G-protein coupled formylpeptide receptor FPR.

Glioma stem cells (GSCs), or stem cell-like glioma cells, isolated from malignant glioma cell lines, were capable of producing vascular endothelial growth factor (VEGF). However, the exact role of such tumour cells in angiogenesis remains unknown. In this study, we isolated a small proportion of CD133+ GSCs from the human glioblastoma cell line U87 and found that these GSCs possessed multipotent differentiation potential and released high levels of VEGF as compared with CD133(-) tumour cells. The CD133+ GSCs also formed larger xenograft tumours that contained higher VEGF immunoreactivity and denser microvessels. Moreover, GSCs expressed a functional G protein-coupled formylpeptide receptor FPR, which was activated by a chemotactic peptide ligand, N-formylmethionyl-leucyl-phenylalanine (fMLF), to mediate calcium flux and the production of VEGF by GSCs. Our results indicate that FPR expressed by human GSCs may play an important role in glioma angiogenesis.

Rapid detection of H5 avian influenza virus by TaqMan-MGB real-time RT-PCR.

AIMS: Real-time reverse transcription-polymerase chain reaction (RT-PCR) assay based on a TaqMan-minor groove binder (MGB) probe was developed for the rapid detection of avian influenza virus subtype H5. METHODS AND RESULTS: Conserved regions in the haemagglutinin genes of avian influenza viruses subtype H5 served as targets for the primers and TaqMan-MGB probe design. Concentrations of primers and probe were optimized to improve the sensitivity and specificity of the reactions. A plasmid containing the haemagglutinin gene was constructed and in vitro transcribed for a quantitative assay of copy numbers of the target gene. The results revealed that the optimal concentration of primers and probe was 640 and 480 nmol l(-1), respectively. The threshold of 100 copies of target molecules could be detected. The linear range for detection was determined as 10(2) to 10(8) molecules in reaction. CONCLUSIONS: It took less than 3 h to complete the detection from viral RNA extraction, with good sensitivity and repeatability. SIGNIFICANCE AND IMPACT OF THE STUDY: Real-time RT-PCR assay with MGB probe was an effective means for quick and quantitative laboratory detection and monitoring of H5 avian influenza viruses.

Morphological and rheological properties of the three different species of basidiomycetes Phellinus in submerged cultures.

AIMS: The objective of this work was to investigate the morphological and rheological properties in submerged culture of the three different basidiomycetes Phellinus (P. baumii, P. gilvus and P. linteus) that produce pharmacologically important exopolysaccharides (EPS). METHODS AND RESULTS: In flask cultures, pH proved to be a critical factor affecting mycelial growth, morphological change and EPS production. The macroscopic morphologies observed under different pHs in flask cultures were also comparable: i.e. starfish-like pellets with a lesser extent of free mycelium appeared in P. baumii, whereas smooth pellets with higher amounts of free mycelium were observed in P. gilvus and P. linteus. The pelleted fermentations were further characterized in a 5-l stirred-tank fermenter by image analysis with respect to mean diameter, core area and pellet circularity. Phellinus baumii showed the largest pellet size (5.2 mm in diameter), whereas P. linteus had extremely small and spherical pellets. The culture broth of P. baumii and P. gilvus yielded extremely high apparent viscosities, ranging from 5 to 7 Pa s. CONCLUSIONS: Three important species of Phellinus showed significantly different morphological and rheological properties. The morphological variation of the three Phellinus species was closely linked to EPS productivity and the apparent viscosity of the whole broth. SIGNIFICANCE AND IMPACT OF THE STUDY: The morphological change in the three species of Phellinus was a good indicator for identifying cell activity for EPS production. Our finding may be beneficial for further optimization of other fungal fermentation processes for large-scale production of EPS.

Effect of aeration and agitation on the production of mycelial biomass and exopolysaccharides in an enthomopathogenic fungus Paecilomyces sinclairii.

AIMS: The objective of the present study was to investigate the influence of aeration rate and agitation intensity on the production of mycelial biomass and exopolysaccharide (EPS) in Paecilomyces sinclairii. METHODS AND RESULTS: The P. sinclairii was cultivated under various aeration and agitation conditions in a 5 l stirred-tank bioreactor. The highest mycelial biomass (30.5 g l-1) and EPS production (11.5 g l-1) were obtained at a high aeration rate (3.5 v.v.m.) and at a high agitation speed (250 rev min-1). The apparent viscosities (6000-8000 cP) of fermentation broth increased rapidly towards the end of fermentations at high aeration and agitation conditions. CONCLUSIONS: The high level of dissolved oxygen achieved at a high aeration rate (3.5 v.v.m.) associated with higher hyphal density eventually resulted in enhanced EPS production. Agitation intensity was also proved to be a critical factor influencing on both the mycelial biomass and EPS production: high agitation speeds up to 250 rev min-1 were preferred to the yields of biomass and EPS production. SIGNIFICANCE AND IMPACT OF THE STUDY: The critical effects of aeration and agitation in the culture process of P. sinclairii were found, which is widely applicable to other kinds of basidiomycetes or ascomycetes in their submerged culture processes.

Production and molecular characteristics of four groups of exopolysaccharides from submerged culture of Phellinus gilvus.

AIMS: The objective of the present study was to determine the optimal culture conditions for the production of four groups of exopolysaccharides (EPSs) in Phellinus gilvus by submerged culture and to investigate their molecular properties by multi-angle laser-light scattering (MALLS) analysis. METHODS AND RESULTS: The optimal temperature and initial pH for the production of both mycelial biomass and EPSs in P. gilvus by submerged flask cultures were found to be 30 degrees C and pH 9.0, respectively. Glucose and corn steep powder were the most suitable carbon and nitrogen source for both mycelial biomass and EPS production. Optimal medium composition was determined to be glucose 30 g l-1, corn steep powder 5 g l-1, MgSO4 1.23 g l-1, KH2PO4 0.68 g l-1, and K2HPO4 0.87 g l-1. Four groups of EPSs (Fr-I, II, III, and IV) were obtained from the culture filtrates by gel filtration chromatography on Sepharose CL-4B and characterized by size exclusion chromatography (SEC) coupled with MALLS. The weight average molar mass (Mw) of Fr-I, Fr-II, Fr-III and Fr-IV were determined to be 8.628 x 106 (+/-129 420), 1.045 x 106 (+/-19 855), 61.09 x 104 (+/-1244), and 33.55 x 104 (+/-134) g mol-1, respectively. CONCLUSIONS: Under optimal culture conditions, the maximum EPS production in a 5-l stirred fermenter indicated 5.3 g l-1 after 11 days of fermentation. The SEC/MALLS analysis revealed that Fr-I, which has extremely high molecular weight, was presumably an aggregate of complex polysaccharides forming a compact globular shape; whereas Fr-II was nearly spherical, Fr-III and Fr-IV were rod-like chains in an aqueous solution. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report on the production of high amounts of EPSs from liquid-culture of the basidiomycete, P. gilvus. The SEC/MALLS approach used in this study could be useful in providing greater insight into the characterization of the mushroom polysaccharides without carrying out elaborate fractionation procedures prior to analysis.

Optimization of submerged culture process for the production of mycelial biomass and exo-polysaccharides by Cordyceps militaris C738.

AIMS: The objective of the present study was to determine the optimal culture conditions for mycelial biomass and exo-polysaccharide (EPS) by Cordyceps militaris C738 in submerged culture. METHODS AND RESULTS: The optimal temperatures for mycelial biomass and EPS production were 20 degrees C and 25 degrees C, respectively, and corresponding optimal initial pHs were found to be 9 and 6, respectively. The suggested medium composition for EPS production was as follows: 6% (w/v) sucrose, 1% (w/v) polypeptone, and 0.05% (w/v) K2HPO4. The influence of pH on the fermentation broth rheology, morphology and EPS production of C. militaris C738 was carried out in a 5-l stirred-tank fermenter. The morphological properties were comparatively characterized by pellet roughness and compactness by use of image analyser between the culture conditions with and without pH control. The roughness and compactness of the pellets indicated higher values at pH-stat culture (pH 6.0), suggesting that larger and more compact pellets were desirable for polysaccharide production (0.91 g g(-1) cell d(-1). CONCLUSIONS: Under the optimized culture conditions (with pH control at 6), the maximum concentration of biomass and EPS were 12.7 g l(-1) and 7.3 g l(-1), respectively, in a 5-l stirred-tank fermenter. SIGNIFICANCE AND IMPACT OF THE STUDY: The critical effect of pH on fungal morphology and rheology presented in this study can be widely applied to other mushroom fermentation processes.

Influence of nutritional conditions on the mycelial growth and exopolysaccharide production in Paecilomyces sinclairii.

AIMS: The objective of the study was to optimize the submerged culture conditions for the production of exopolysaccharide from Paecilomyces sinclairii. METHODS AND RESULTS: The optimal temperature and initial pH for exopolysaccharide production by Paecilomyces sinclairii in shake flask culture were found to be 30 degrees C and 6.0, respectively. Sucrose (60 g l(-1)) and corn steep powder (10 g l(-1)) were the most suitable carbon and nitrogen source for exopolysaccharide production. CONCLUSIONS: Under optimal culture medium, the maximum exopolysaccharide concentration in a 5-l stirred-tank fermenter indicated 7.4 g l(-1), which was approximately three times higher than that in basal medium. The maximum specific growth rates (micro max) and yield coefficient (Y(P/S)) in the optimal culture medium was 0.16 h(-1) and 0.19, respectively. SIGNIFICANCE AND IMPACT OF THE STUDY: The optimal culture conditions reported in this article can be widely applied to the processes for submerged cultures of other mushrooms.

Molecular therapy with recombinant antisense c-myc adenovirus for human gastric carcinoma cells in vitro and in vivo.

BACKGROUND AND AIMS: This study used a recombinant antisense c-myc adenovirus (Ad-ASc-myc) to evaluate how alterations of c-myc expression in the SGC7901 human gastric carcinoma cells could influence the proliferation, apoptosis and the growth of human gastric tumors in nude mice. METHODS: The human gastric carcinoma cell line, SGC7901, treated with Ad-ASc-myc or adenovirus recombinants carrying LacZ gene (Ad-LacZ) were analyzed by using X-gal stain, MTT, DNA ladder, TUNEL assay, flow cytometric analysis, polymerase chain reaction and western blot in vitro. The tumorigenicity and experimental therapy in nude mice models were assessed in vivo. RESULTS: The Ad-ASc-myc could strongly inhibit cell growth and induce apoptosis in SGC7901 cells. The proliferation of the Ad-ASc-myc-infected SGC7901 cells was reduced by 44.1%. The mechanism of killing gastric carcinoma cells by Ad-ASc-myc was found to be apoptosis, which was detected by the use of a DNA ladder, TUNEL and flow cytometric analysis. Infection of Ad-ASc-myc in nude mice showed that all three mice failed to form tumors from the 7 to 30 day period, compared with injection of Ad-LacZ and parent SGC7901 cells. Experimental therapy on the nude mice bearing subcutaneous tumors of SGC7901 cells showed that intratumor instillation of Ad-ASc-myc inhibited the growth of the tumors. Recombinant antisense c-myc adenovirus-treated tumors were inhibited by 68.9%, compared with tumors injected with Ad-LacZ and control (LacZ and phosphate-buffered saline). CONCLUSION: The expression of Ad-ASc-myc can inhibit growth and induce apoptosis of gastric cancer cells in vitro and in vivo and thus is a potential clinical utility in gene therapy for the treatment of gastric carcinoma.

Differential north to south gastric cancer-duodenal ulcer gradient in China. China Ulcer Study Group.

There are suggestions that duodenal ulcer protects individuals from gastric cancer and that rice is ulcerogenic while wheat is gastro-protective. We aimed to examine the relationship of gastric cancer, duodenal and gastric ulcers in different geographical regions in China and identified dietary risk factors for duodenal ulcer and gastric cancer. The prevalence of peptic ulcer and gastric cancer among symptomatic patients in eight major cities, four each from the north and the south representing all the six defined regions of China were studied. Endoscopy and case records over a 10 year period were reviewed and cases of confirmed duodenal and gastric ulcer and gastric cancer, together with the total number of endoscopies performed per year, were recorded. Rates were expressed as cases/1000 endoscopies. Results were compared to another epidemiological study on diet and mortality in the same regions in China conducted at the same time. Duodenal ulcer rates were 2.4-fold higher in southern China than northern China, whereas gastric cancer rates were 1.6-fold higher in the north than in the south. Correlation studies showed for the first time an inverse linear relationship between the gastric cancer rates and the duodenal ulcer rates (r=-0.8076, P=0.015), as well as the duodenal ulcer: gastric ulcer ratios (r=-0.9133, P=0.002). Gastric ulcer rates were higher in southern China but did not correlate with the gastric cancer rates (r=0.1455, P=0.731). Duodenal ulcer rates were found to be related to daily rice intake (r=0.8554, P=0.029) and inversely related to daily wheat flour intake (r=-0.8472, P=0.033). Gastric cancer rates were not related to any dietary risk factors tested. We concluded there was an inverse relationship between gastric cancer rates and duodenal ulcer rates. Although duodenal ulceration and gastric cancer are both linked to Helicobacter pylori infection, the findings of this study indicate independent additional aetiological factors for the pathogenesis of these conditions. Dietary factors such as rice or wheat intake may play a role.

Mechanical functional role of non-atherosclerotic intimal thickening.

Arteries adjust to alterations in wall shear stress or tensile stress by changes in diameter, wall thickness, structure and composition. The intima participates in these adaptive reactions, particularly when changes in mechanical stresses are imposed after physiologic stress levels have been established during growth. Decreased wall shear stress due to decreased flow, flow separation or complex flow patterns, or increases in tensile stress due to increases in pressure or radius stimulate non-atherosclerotic intimal proliferation. Intimal fibrocellular hypertrophy (IFH), in the form of compact fibrocellular layers resembling the media, stabilizes when the lumen diameter is reduced sufficiently or wall thickness is increased sufficiently to restore baseline wall shear or tensile stress. Reactive-adaptive intimal proliferation is not necessarily self-limiting and may continue in the form of intimal hyperplasia (IH) which is relatively matrix-free and poorly organized. If mural and intimal changes do not result in restoration of baseline wall shear and tensile stress, IH may proceed to further narrowing and stenosis. Identification of the cellular and molecular mechanisms which underly the responses which link flow to diameter, diameter and pressure to mural restructuring, and mural restructuring to intimal thickening should provide new insights into the nature of vessel adaptations in the absence or presence of atherogenesis.

A clinical, endoscopic and pathological study of ulcer-carcinoma: report of 210 cases.

A multicentre retrospective study of ulcer-carcinoma was carried out in 16 hospitals in China, with the aim of examining the correlation between pre-cancerous lesions and malignant change associated with benign gastric ulcer. Malignant change occurred at 2% over a variable period of 6 months to 15 years. About two-thirds of the ulcer cancers were found to be tubular adenocarcinoma.

Aneurysmal enlargement of the aorta during regression of experimental atherosclerosis.

We explored the relationship between regression of diet-induced atherosclerosis and aneurysmal enlargement of the aorta in cynomolgus monkeys. Atherosclerotic plaques were induced in 17 monkeys by feeding them a diet containing 2% cholesterol and 25% peanut oil for 6 months (group I, n = 6; group III, n = 6) or 12 months (group II, n = 5). Regression was induced in group III by feeding a regression diet consisting of 0.25% cholesterol and 15% corn oil in a standard chow diet, for 6 months after the 6-month induction period. Serum cholesterol was 788 +/- 80 mg/dl after 6 months of induction, 508 +/- 53 mg/dl after the 12-month induction period, and 198 +/- 15 mg/dl in the regression group at 12 months. Aortas were fixed in situ under conditions of controlled pressure perfusion, and transverse sections of the unopened vessels were taken at standard levels in the midthoracic and abdominal aortic segments. The area encompassed by the internal elastic lamina was taken as a measure of artery size. Plaques were abundant in abdominal and thoracic sections after the 6- and 12-month induction periods, and no significant difference was observed in lumen area or artery size between the groups. The ratio of abdominal to thoracic aortic plaque area was markedly reduced in the regression group (0.3 +/- 0.2 for regression compared with 0.6 +/- 0.3 for 6-month induction and 1.3 +/- 0.2 for 12-month induction animals; p less than 0.05 for both). A twofold increase was observed in abdominal aortic lumen area in the regression group (10.0 +/- 1.5 mm2 for regression compared with 5.6 +/- 0.7 mm2 for the 6-month and 4.2 +/- 0.7 mm2 for the 12-month induction groups; p less than 0.05 for both) as well as a twofold increase in internal elastic lamina area (10.5 +/- 1.5 mm2 compared with 6.0 +/- 0.7 mm2 for the 6-month and 5.9 +/- 0.8 mm2 for the 12-month induction group; p less than 0.05 for both). Aortic enlargement in the regression group was accompanied by a reduction in media thickness in the abdominal aorta. No significant vessel enlargement or alteration in media thickness occurred in the thoracic aorta. One of six regression animals (17%) had a threefold enlargement of the abdominal aorta and was thought to have a manifest aneurysm.(ABSTRACT TRUNCATED AT 400 WORDS)

Hypertension sustains plaque progression despite reduction of hypercholesterolemia.

To assess the effect of hypertension on diet-induced coronary artery plaques after a return to a nonatherogenic diet, 10 cynomolgus monkeys were fed an induction regimen containing 2% cholesterol and 25% peanut oil for 6 months and then were subjected to midthoracic aortic coarctation to induce hypertension. The animals were then fed a nonatherogenic "prudent" ration for 6 additional months (hypertension-regression group). Twelve additional monkeys were fed the atherogenic diet for 6 months; six were killed (lesion-induction control group) and six were changed to the prudent diet for 6 additional months without coarctation (normotension-regression control group). At the end of the induction period, cholesterol levels averaged 744 +/- 178 mg/dl for the 22 animals and were similar for the three groups throughout the induction period. For the animals restored to the nonatherogenic diet (hypertension-regression and normotension-regression groups), serum cholesterol levels fell to 486 +/- 252 mg/dl at 1 month, to 341 +/- 162 mg/dl at 2 months, and to 234 +/- 78 mg/dl at 6 months. There was no significant difference between the hypertensive and normotensive animals. Six months after coarctation, blood pressure proximal to the coarctations for the hypertension-regression group ranged from 100/60 to 220/145 mm Hg with a mean of 166/103 +/- 36/28 mm Hg. Cross-sectional area of coronary plaques was somewhat lower for the normotension-regression control group compared with the lesion-induction control group, but the difference was not significant. Plaque area was, however, markedly greater in the hypertension-regression group than in either the lesion-induction or the normotension-regression groups (p less than 0.05 for each) despite progressive reduction in hyperlipidemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Limited effects of hyperlipidemia on the arterial smooth muscle response to mechanical stress.

Arteries respond to long-term changes in flow rate by alterations in caliber that tend to restore wall shear stress to normal baseline levels. Changes in radius, pressure, or geometric configuration elicit changes in structure and composition of the media in keeping with the altered level and distribution of tensile stresses. Similar stabilizing adaptations occur in the presence of conditions that induce the formation of atherosclerotic plaques, but the ultimate effectiveness of these reactions is variable. Several recent experiments provide information on the possible effects of hyperlipidemia on the smooth muscle cell (SMC) response to normal or increased levels of mechanical stress: (a) Normolipemic serum increases collagen synthesis by SMCs grown on purified elastin membranes compared to synthesis in serum-free medium, but synthesis is not further enhanced by cyclic stretching of the cells. Collagen production increase is less marked in hyperlipemic serum, but cyclic stretching raises synthesis to a degree comparable to that noted for serum-free medium. (b) The increase in artery diameter in response to increased flow rate and the elaboration of media components in relation to the increase in diameter are not hampered by hyperlipidemia. (c) The compensatory enlargement of arteries in response to plaque formation is not prevented by hyperlipidemia even in the presence of hypertension. (d) The healing of a transmural necrotizing injury of the media is, however, retarded and incomplete in the presence of hyperlipidemia. These findings indicate that hyperlipidemia per se does not necessarily interfere with the SMC response to mechanical stimuli. The usual adaptive reactions remain intact.(ABSTRACT TRUNCATED AT 250 WORDS)