[Patient-reported outcomes of locally advanced gastric cancer undergoing robotic versus laparoscopic gastrectomy: a randomized controlled study].

Objective: To compare the patient-reported outcomes and short-term clinical outcomes between robotic-assisted and laparoscopic-assisted radical gastrectomy for locally advanced gastric cancer. Methods: This single-center prospective randomized controlled trial was conducted in the Department of Gastrointestinal Surgery,Affiliated Hospital of Qingdao University from October 2020 to August 2022. Patients with locally advanced gastric cancer who were to undergo radical gastrectomy were selected and randomly divided into two groups according to 1∶1, and received robotic surgery and laparoscopic surgery, respectively. Patient-reported outcomes and short-term clinical outcomes (including postoperative complications, surgical quality and postoperative short-term recovery) were compared between the two groups by t test, Mann-Whitney U test, repeated ANOVA, generalized estimating equation, χ2 test and Fisher's exact test. Results: A total of 237 patients were enrolled for modified intention-to-treat analysis (120 patients in the robotic group, 117 patients in the laparoscopic group). There were 180 males and 59 females, aged (63.0±10.2) years (range: 30 to 85 years). The incidence of postoperative complications was similar between the robotic group and laparoscopic group (16.7% (20/120) vs. 15.4% (18/117), χ2=0.072, P=0.788). The robotic group had higher patient-reported outcomes scores in general health status, emotional, and social domains compared to the laparoscopic group, differences in time effect, intervention effect, and interaction effect were statistically significant (general health status: χ2 value were 275.68, 3.91, 6.38, P value were <0.01, 0.048, 0.041; emotional: χ2 value were 77.79, 6.04, 6.15, P value were <0.01, 0.014, 0.046; social: χ2 value were 148.00, 7.57, 5.98, P value were <0.01, 0.006, 0.048). However, the financial burden of the robotic group was higher, the differences in time effect, intervention effect and interaction effect were statistically significant (χ2 value were 156.24, 4.08, 36.56, P value were<0.01, 0.043,<0.01). Conclusion: Compared to the laparoscopic group, the robotic group could more effectively relieve postoperative negative emotions and improve recovery of social function in patients.

[Tumor necrosis factor-related apoptosis-inducing ligand gene polymorphism and its plasma phenotype in relation to Crohn's disease].

Objectives: To investigate the associations of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) gene polymorphism and plasma soluble TRAIL level (sTRAIL) with Crohn's disease (CD) and to retrospectively analyze the effects of TRAIL gene variants and plasma sTRAIL levels on clinical response to infliximab (IFX). Methods: From January 2012 to January 2021, 312 CD patients [205 males, 107 females, average age (33.9±9.8) years] and 514 age-and gender-matched healthy controls [304 males, 210 females, average age (34.9±9.4) years] were recruited from the Department of Gastroenterology, the Second Affiliated Hospital of Wenzhou Medical University. Among them, 72 patients with active CD who were ineffective or intolerant to traditional drug therapy regularly received IFX (5 mg/kg) treatment. According to the changes in the Harvey-Bradshaw index (HBI) and the Simplified Endoscopic Score for Crohn's Disease (SES-CD) in the 14th week, these patients were classified into response group (a decrease in HBI≥3 or a decrease in SES-CD≥50%) and non-response group. TRAIL (rs1131568) gene polymorphism was analyzed by matrix-assisted laser desorption/ionization time of flight mass spectrometry technique. The plasma sTRAIL level was examined by enzyme-linked immunosorbent assay (ELISA). Based on the Montreal CD classification criteria, all CD patients were divided into different subgroups. Finally, a comprehensive analysis was performed to investigate the relationship between TRAIL (rs1131568) gene polymorphism, the plasma sTRAIL level and the risk of CD, the clinicopathological characteristics of CD patients, and the clinical response to IFX. Results: The recessive model analysis showed that the homozygous variant genotype (CC) was more prevalent in patients with moderately to severely active CD than in those with mildly active CD (45.34% vs 29.23%, P=0.005). Both variant allele (C) and homozygous variant genotype (CC) in patients with stricturing and penetrating CD were more frequent than those in patients with non-stricturing and non-penetrating CD (65.48% vs 57.53%, P=0.046; 49.21% vs 31.18%, P=0.001). The dominant model analysis showed that variant allele (C) and variant genotype (TC+CC) was higher in CD patients with perianal lesions than in those without perianal lesions (66.83% vs 58.17%, P=0.037; 92.31% vs 78.37%, P=0.002). The average plasma sTRAIL level was higher in CD patients than in healthy controls [(243.04±42.74) ng/L vs (194.16±31.14) ng/L, P<0.001]. Compared with the patients with mildly active CD, the plasma sTRAIL level was increased in those with moderately to severely active CD [263.47(242.09, 281.91) ng/L vs 231.13(211.11, 247.11) ng/L, P<0.001]. The same conclusion was also drawn for the patients with stricturing and penetrating CD in contrast to those with non-stricturing and non-penetrating CD [266.18 (246.68, 289.91) ng/L vs 227.19 (204.57, 249.59) ng/L, P<0.001]. The plasma sTRAIL level was also higher in patients with perianal disease than in those without perianal disease [(261.40±41.51) ng/L vs (233.86±40.41) ng/L, P<0.001]. Multiple linear regression analysis further showed that disease activity (ß=22.640, P<0.001) and homozygous variant genotype (CC) (ß=16.814, P<0.001) may be positively related to the plasma sTRAIL level in CD patients independently. At the 14th week of IFX treatment, the plasma sTRAIL level in the response group was lower than that in the non-response group [205.98(190.72, 214.56) ng/L vs (238.33±29.38) ng/L, P<0.001]. Compared with week 0, the plasma sTRAIL level was decreased in the response group in the 14th week [(205.98 (190.72, 214.56) ng/L vs (239.89±42.43) ng/L, P<0.001]. Non-conditional logistic regression analysis showed that variant allele (C) and variant genotype (TC+CC) were less frequent in the response group than in the non-response group (53.33% vs 70.83%, P=0.037; 70.00% vs 91.67%, P=0.036). Conclusions: The increased plasma sTRAIL level may be a risk factor for CD. TRAIL (rs1131568) gene variation and the increase of plasma sTRAIL level may be associated with the increased disease activity of CD and may be the risk factors for stenosis, penetration, and perianal lesions in CD patients. In addition, TRAIL (rs1131568) gene variation or the increase of plasma sTRAIL level may be related to no response to IFX treatment in CD patients.

[A preliminary study on the improved efficacy of mesalazine combined with vitamin D3 in ulcerative colitis].

Objective: To analyze the influence of vitamin D3 supplementation on the clinical efficacy of mesalazine in patients with ulcerative colitis (UC). Methods: From January 2015 to December 2020, patients with mild-to-moderate active UC were retrospectively and continuously enrolled, who accepted mesalazine treatment for at least 12 months at the Second Affiliated Hospital of Wenzhou Medical University. According to simultaneous supplement of vitamin D3 (125 IU/d), the patients were divided into study group and control group. Demographic and disease characteristics, serum 25-hydroxyvitamin D[25(OH)D] levels and other information were collected through retrieving hospital database. Student's t-test, Mann-Whitney U test and Chi-square test were applied for comparison of disease characteristics. The changes of modified Mayo scores[ΔMayo] and 25(OH)D[Δ25(OH)D] were compared before and after treatment by paired t-test, Wilcoxon signed rank test and Chi-square test. Multiple linear regression model was used to analyze the independent factors affecting ΔMayo and Δ25(OH)D, and variables with P-values less than 0.20 in the univariate analysis were allowed for further multivariate analysis. Results: A total of 74 UC patients (44 males, 30 females), with median age (range) 39.5 (20-76) years old, were analyzed and respectively assigned into study group (n=36) and control group (n=38). In study group, the average level of serum 25(OH)D was significantly increased at month 12 compared with that at baseline [(22.87±7.30) µg/L vs. (18.15±7.48) µg/L,P<0.001]. However, no significant elevation of serum 25(OH)D was found in control group [(19.17±8.49) µg/L vs. (19.82±9.47) µg/L,P=0.466]. Furthermore, there was a significant decrease of modified Mayo score [-3(-4.75, -1.25) vs.-2(-3.25, 0), P=0.034] and a higher clinical remission rate (55.6% vs. 28.9%, P=0.020) at month 12 in study group than those in control group. In addition, according to the baseline level of serum 25(OH)D before mesalazine treatment, 74 UC patients were divided into vitamin D deficiency group (n=38, serum 25(OH)D<20 µg/L) and non-deficiency group (n=36, serum 25(OH)D≥20 µg/L). At month 12 in vitamin D deficiency group, patients with vitamin D3 supplementation had a greater decline in modified Mayo score [-4(-5.75, -2) vs.-2(-4, 0), P=0.048] and a higher clinical remission rate (60.0% vs. 22.2%, P=0.019) compared with those without. Conclusions: In patients with mild-to-moderate active UC receiving mesalazine treatment, vitamin D3 supplementation may improve the clinical efficacy, especially in patients with vitamin D deficiency.

[The effects of robotic-assisted versus laparoscopic-assisted radical right hemicolectomy on short-term outcome and long-term prognosis based on propensity score matching].

Objective: To compare the short-term and long-term outcomes between robotic-assisted and laparoscopic-assisted radical right hemicolectomy in patients with adenocarcinoma of the right colon. Methods: Retrospective review of a prospectively collected database identified 288 right colon cancer patients who underwent either robotic-assisted (n=57) or laparoscopic-assisted right hemicolectomy (n=231) between October 2014 and October 2020 at Department of Gastrointestinal Surgery, the Affiliated Hospital of Qingdao University. There were 161 males and 127 females, aging (60.3±12.8) years (range: 17 to 86 years). After propensity score matching as 1∶4 between robotic-assisted and laparoscopic-assisted right hemicolectomy, there were 56 cases in robotic group and 176 cases in laparoscipic group. Perioperative outcomes and overall survival were compared between the two groups using t test, Wilcoxon rank sum test, χ2 test, Fisher exact test, Kaplan-Meier method and Log-rank test, respectively. Results: The total operative time was similar between the robotic and laparoscopic group ((206.9±60.7) minutes vs. (219.9±56.3) minutes, t=-1.477, P=0.141). Intraoperative bleeding was less in the robotic group (50 (20) ml vs. 50 (50) ml, Z=-4.591, P<0.01), while the number of lymph nodes retrieved was significantly higher (36.0±10.0 vs. 29.0±10.1, t=4.491, P<0.01). Patients in robotic group experienced significantly shorter hospital stay, shorter time to first flatus, and defecation (t: -2.888, -2.946, -2.328, all P<0.05). Moreover, the overall peri-operative complication rate was similar between robotic and laparoscopic group (17.9% vs. 22.7%, χ²=0.596,P=0.465). The 3-year overall survival were 92.9% and 87.9% respectively and the 3-year disease-free survival rates were 83.1% and 82.6% with no statistical significance between the robotic and laparoscopic group (P>0.05). Conclusions: Compared to laparoscopic-assisted right hemicolectomy, robot-assisted right hemicolectomy could improve some short-term clinical outcomes. The two procedures are both achieving comparable survival.

[The effect of perioperative ERAS pathway management on short-and long-term outcomes of gastric cancer patients].

Objective: To compare postoperative short-term outcomes and long-term prognosis between perioperative Enhanced Recovery After Surgery (ERAS) and conventional pathways protocols in gastric cancer patients. Methods: This is a single institute retrospective cohort study, all patients were pathologically proved to be gastric adenocarcinoma, underwent standard radical gastrectomy with D2 lymphadenectomy during the period of 2007-2012. Total 2124 cases were eligible to be analysed and divided into ERAS groups and Non-ERAS group according to the different perioperative pathway protocol. Propensity score matching method (in SPSS, 24.0 version, IBM Company) was used to balance the baseline characteristics. Two groups were matched in a 1∶1 ratio. There were 521 cases per group after matched. The short-term clinical outcomes (postoperative complications, length of hospital stay, blood loss, 30-day re-admission rate, etc.) and overall 5-year survival rates were compared between the two groups. Results: The incidence of overall postoperative complications was similar between the two groups (ERAS group=18.4%, non-ERAS group=19.4%, P=0.69), including anastomotic leakage, abdominal hemorrhage, etc. But the incidence of SSI, atelectasis, and thromboembolic disease in ERAS group was significant lower than that in Non-ERAS group. The number of lymph node harvested, operation time, intraoperative blood loss, postoperative hospital and cost in ERAS group were better than those in non-ERAS group. There were no significant differences in unplanned reoperation (ERAS group=3.1%, non-ERAS group=2.1%, P=0.33), 30 day readmission rate of discharge (ERAS group=6.1%, non-ERAS group=5.6%, P=0.69) and postoperative mortality (ERAS group=0.4%, non-ERAS group=0.2%, P=0.56) between the two groups. The 5-year overall survival rates of non-ERAS group and ERAS group were 66.2% and 72.8% respectively (P=0.007). The subgroup analysis found that 5-year OS rates of stage I were 93.4% and 92.7% (P=0.73), these of stage Ⅱ and Ⅲ were 82.2% vs 75.2% (P=0.007) and 47.6% vs 35.7% (P=0.02) in ERAS group and non-ERAS group respectively. Conclusions: Perioperative ERAS pathway management is safe and feasible for patients with gastric cancer, without increasing the incidence of complications and 30-day readmission rate. This protocol can improve the prognosis of patients with gastric cancer.

[Impact of TRAIL deficiency on Th17 cells in the mice experimental colitis induced by dextran sodium sulphate].

Objective: To investigate the impact of TNF-related apoptosis-inducing ligand (TRAIL) gene knock-out (TRAIL(-/-)) on Th17 cells in the mice colitis induced by dextran sulphate sodium (DSS). Methods: Mice were randomly assigned to 4 subgroups: wild type (WT), TRAIL(-/-), WT colitis and TRAIL(-/-)colitis (n=6/group). Colitis was induced by oral administration of 3.5% DSS for 7 consecutive days. The severity of colitis in each mouse was scored both clinically and histopathologically. Flow cytometry was performed to assess Th17 cell population in peripheral blood mononuclear cells (PBMC) and mesenteric lymph nodes (MLN). The expression levels of Th17 cell markers interleukin (IL)-17A and retinoic acid-related orphan receptor (ROR)-γt in PBMC and MLN were also examined using a quantitative polymerase chain reaction method. Results: Compared with WT group, WT colitis group displayed elevated CD4(+)IL-17A(+) Th17 cells (0.29±0.07 vs 0.08±0.03, 1.20±0.36 vs 0.40±0.11, both P<0.05) and enhanced mRNA expression of IL-17A and ROR-γt in PBMC and MLN (IL-17A: 2.43±0.87 vs 0.37±0.19, 5.03±1.77 vs 1.05±0.48, both P<0.05; ROR-γt: 2.49±0.48 vs 0.93±0.47, 23.75±7.60 vs 1.31±0.90, both P<0.05). After the DSS administration, TRAIL(-/-) group developed more severe colitis than WT group, mainly manifesting higher disease activity index, reduction of colon length and increased infiltration of inflammatory cells. In addition, TRAIL(-/-) colitis group exhibited increased proportion of CD4(+) IL-17A(+) Th17 cells (0.57±0.22 vs 0.29±0.07, P<0.001; 2.92±0.98 vs 1.20±0.36, P<0.000 1) as well as enhanced mRNA expression of IL-17A and ROR-γt in PBMC and MLN when compared with WT colitis group (IL-17A: 4.10±1.96 vs 2.43±0.87, 15.88±2.86 vs 5.03±1.77, both P<0.05; ROR-γt: 4.05±0.62 vs 2.49±0.48, 69.61±10.48 vs 23.75±7.60, both P<0.05). Conclusions: TRAIL deficiency not only promots the number and activity of Th17 cells in PBMC and in MLN, but also aggravats DSS-induced colitis in mice.

[Association of Crohn's disease with aryl hydrocarbon receptor gene polymorphisms and haplotypes].

Objective: To explore the relationship of Crohn's disease (CD) susceptibility to aryl hydrocarbon receptor (AhR) polymorphisms and haplotypes in Han population in Wenzhou city, China. Methods: A total of 310 CD patients and 573 age- and sex-matched healthy controls were enrolled in our study. Three single nucleotide polymorphisms (SNPs) of AhR(rs10249788,rs2158041,rs2066853) were determined by the improved multiple ligase detection reaction technique. Unconditional logistic regression analyses was applied to analyze the allelic and genotypic differences of each SNP between CD patients and controls, as well as their influence on the clinicopathologic characteristics in CD patients. Analyses of linkage disequilibrium and haplotype were performed by Haploview 4.2 software in all study subjects. Results: Compared with the controls, the variant allele (T) and genotype (CT+TT) of (rs2158041) were evidently decreased among CD patients (19.52% vs. 25.04%, P=0.009; 34.19% vs. 44.68%, P=0.003). According to "the Montreal Classification Standards" , CD patients were divided into different subgroups. The variant allele (T) and genotype (CT+TT) of (rs2158041) were significantly lower in patients with terminal ileum CD than in controls (16.79% vs. 25.04%, P=0.005; 28.24% vs. 44.68%, P=0.001). Similar conclusions were also drawn in patients with constricting disease when compared with the controls (15.20% vs. 25.04%, P=0.003; 28.43% vs. 44.68%, P=0.003). The three SNPs above were shown to be in a linkage disequilibrium. Compared with the controls respectively, the frequency of haplotype (CCG) was increased in CD patients (44.73% vs. 39.60%, P=0.039), whereas that of haplotype (CTG) was decreased (18.02% vs. 22.78%, P=0.047). Conclusions: AhR (rs2158041) variation might influence the risk as well as the location and behavior of CD. The haplotype (CCG) possibly increase the risk of CD development, whereas haplotype (CTG) might decrease it.

[Association of Crohn's disease with T cell immunoglobulin and mucin domain 3 gene polymorphisms in Chinese patients].

Objective: To explore the association of Crohn's disease (CD) with T cell immunoglobulin and mucin domain 3 (Tim-3) gene polymorphisms in patients of Zhejiang Han population in China. Methods: A total of 308 CD patients and 573 age- and sex-matched healthy controls were enrolled in our study. Two single nucleotide polymorphisms (SNPs) of Tim-3 (rs1036199 and rs10515746) were examined by the improved multiple ligase detection reaction technique (iMLDR). Analyses of linkage disequilibrium and haplotype were also performed by Haploview 4.2 software in all study subjects. Results: In general, the allele and genotype frequencies of Tim-3 (rs1036199 and rs10515746) were not statistically different between CD patients and the controls (all P>0.05). According to "the Montreal Classification" , CD patients were divided into different subgroups. The variant allele (C) and genotype (AC+ CC) of rs1036199 were more frequent in CD patients with penetrating diseases than in the controls (10.4% vs 1.7%, P=0.002; 20.8% vs 3.5%, P=0.023). Similar conclusions were also drawn for the variant allele (A) and genotype (CA+ AA) of rs10515746 in patients with penetrating diseases when compared with the controls (10.4% vs 2.2%, P=0.000; 20.8% vs 4.2%, P=0.033, respectively). The two SNPs of Tim-3 were in strong linkage disequilibrium (D'=1.0, r2=0.928). The haplotype (AC) formed by their wild-type alleles (A) and (C) was decreased in patients with penetrating CD compared with the controls (89.6% vs 98.3%, P=0.000). However, the haplotype (CA) formed by their variant alleles was more frequent in patients with penetrating CD than in the controls (10.4% vs 1.6%, P=0.000). Conclusions:Tim-3 (rs1036199 and rs10515746) variations might be correlated with the enhanced risk of penetrating diseases in CD patients. Furthermore, the haplotype (AC) and (CA) formed by the two SNPs might be a protective and a risky factor for penetrating CD respectively.

Flavonol glycosides from Elaeagnus bockii (Elaeagnaceae).

A new flavonol glycoside was isolated together with five known glycosides. Their structures were characterized by spectroscopic and chemical studies.

H(infinity) control of uncertain dynamical fuzzy discrete-time systems.

A new kind of dynamical fuzzy model is proposed to represent discrete-time complex systems which include both linguistic information and system uncertainties. A new stability analysis and control system design approach is then developed for this kind of dynamical fuzzy model. Furthermore, a constructive algorithm is developed to obtain the H(infinity) feedback control law. An example is given to illustrate the application of the method.

Flavonol glycosides from Elaeagnus lanceollata (Elaeagnaceae).

Two new flavonol glycosides were isolated together with two known glycosides and an ester from the leaves of E. lanceollata Warb. Their structures were characterized by spectroscopic methods.

Minor methylated pyranoamentoflavones from Calophyllum venulosum.

Two new biflavonoids, pyranoamentoflavone 7-methyl ether (1) and pyranoamentoflavone 4'-methyl ether (2), have been isolated from the leaves of Calophyllum venulosum. The structures of these two new compounds were elucidated by spectroscopic data.

Purification and characterization of a Pseudomonas sp. lipase and its properties in non-aqueous media.

An extracellular lipase from Pseudomonas sp. was purified to homogeneity by extraction, Bio-gel P-10 chromatography and Superose 12B chromatography, and a 37-fold purification was attained. The purified enzyme showed a single band when it was subjected to SDS/PAGE and isoelectric focusing. The SDS/PAGE electrophoresis indicated a molecular mass of 30 kDa for this lipase. Its isoelectric point was 4.5. The optimum pH and temperature for hydrolysis were 7.0-9.0 and 45-60 degrees C, respectively. The enzyme was stable between pHs 6 and 12 and below 60 degrees C. In the presence of Ca(2+) and Bi(3+), the lipase activity was dramatically enhanced by 250% and 154%, respectively. Fe(3+), Fe(2+), Al(3+), Zn(2+) and Mn(2+) could inhibit this lipase, but Ag(+) and Pb(2+) showed no influence on hydrolysis activity. Properties of purified lipase for lactonization in organic solvent were also determined. The purified lipase displayed the characteristic of 'pH memory' in organic media. This lipase was also thermostable in organic solvent with an optimum temperature range from 45 to 60 degrees C. Salt dramatically affected the lactonization activity of this lipase.

Stability analysis of fuzzy control systems.

A discrete-time fuzzy control system which is composed of a dynamic fuzzy model and a fuzzy state feedback controller is proposed. Stability of the fuzzy control system is discussed and a sufficient condition to guarantee the stability of the system is given in terms of uncertain linear system theory. The results in this paper improve our previous stability results. An example is used to show the proposed method.

Thyroxine stimulates phosphatidylglycerolphosphate synthase activity in rat heart mitochondria.

The effect of administration of exogenous thyroxine on mitochondrial phosphatidylglycerol content and biosynthesis was investigated in rat heart ventricles. Rats were treated for 5 consecutive days with thyroxine (250 mg/kg body weight) and on the sixth day after an overnight fast the mass of ventricular mitochondrial phosphatidylglycerol and cardiolipin content were determined. Saline-treated animals served as controls. Thyroxine treatment did not affect body weight but increased heart weight 30% compared with controls. In addition, the ratio of heart weight/body weight (x 1000) was increased from 0.69 in controls to 0.89 in thyroxine-treated rats consistent with this model. Thyroxine-treatment resulted in a 34% increase (P < 0.05) in phosphatidylglycerol and a 23% increase (P < 0.05) in cardiolipin content in ventricular mitochondrial fractions compared with controls. The mechanism for the increase in ventricular mitochondrial phosphatidylglycerol was investigated. Phosphatidic acid:cytidine-5'-triphosphate-1,2-diacylglycerol cytidylyltransferase and phosphatidylglycerolphosphate phosphatase activities were unaltered in the ventricular mitochondria of thyroxine-treated rats. In contrast, phosphatidylglycerolphosphate synthase activity was increased 3.5-fold (P < 0.05) in these mitochondrial fractions compared with controls. As a control for the effectiveness of thyroxine on mitochondria, cardiolipin synthase activity was determined. A 2.8-fold increase (P < 0.05) in cardiolipin synthase activity was observed in ventricular mitochondrial fractions of thyroxine-treated rats compared with controls. We postulate that thyroxine-treatment of rats produces an increase in the pool size of ventricular mitochondrial phosphatidylglycerol and that the mechanism is an increase in phosphatidylglycerolphosphate synthase activity.

Oleate stimulation of incorporation of exogenous glycerol into cardiolipin in isolated perfused rat heart does not involve direct activation of the CDP-DG pathway.

Oleate has been shown previously to stimulate the in vitro activity of phosphatidylglycerol-phosphatase, an important enzyme in the cytidine-5'-diphosphate-1,2-diacyl-sn-glycerol pathway of phosphatidylglycerol and cardiolipin biosynthesis. In this study the in vivo effect of oleate on the biosynthesis of new phosphatidylglycerol and cardiolipin was investigated in the heart. Hearts were perfused for 60 min with Krebs-Henseleit buffer containing [1,3-3H]glycerol and 0.6 mM albumin in the absence or presence of 0.6 or 1.2 mM oleate. Total incorporation of radioactivity was higher in the oleate-treated hearts compared with controls and this was due to an exclusive incorporation of radioactive glycerol into the organic phase. Also, the radioactivity incorporated into phosphatidylglycerol and cardiolipin was higher in the oleate-treated hearts compared with controls; however, the increase was greater in hearts perfused with 0.6 mM oleate compared with 1.2 mM oleate, indicating that pathophysiological concentrations of oleate may attenuate the oleate-induced stimulation of glycerol incorporation into polyglycerophospholipids. The pool size of phosphatidylglycerol and cardiolipin were unchanged in oleate-perfused hearts compared with controls. To investigate if the biosynthesis of phosphatidylglycerol and cardiolipin via the cytidine-5'-diphosphate-1,2-diacyl-sn-glycerol pathway was authentically stimulated by oleate hearts were pulse labeled for 15 min with 0.1 mM [1,3-3H]glycerol and subsequently chased for 60 min with 0.1 mM glycerol in the absence or presence of 0.6 mM oleate in the perfusate. Radioactivity incorporated into phosphatidylglycerol and cardiolipin was unchanged compared with controls. Our data indicate that oleate increases the incorporation of exogenous glycerol into polyglycerophospholipids but not accelerate synthesis from prelabeled precursor pools. Accordingly, oleate does not appear to stimulate directly enzymes of the cytidine-5'-diphosphate-1,2-diacyl-sn-glycerol pathway in vivo.

Cardiolipin is synthesized from exogenous phosphatidylglycerol in rat heart.

De novo biosynthesis of phosphatidylglycerol and cardiolipin in the isolated intact rat heart was shown to occur from newly synthesized phosphatidic acid via the formation of cytidine-5'-diphosphate-1,2-diacylglycerol (Hatch, G.M. (1994) Biochem. J. 297, 201-208). The biosynthesis of new cardiolipin was investigated in isolated rat hearts perfused with exogenous phosphatidylglycerol. Phosphatidylglycerol was rapidly (within 5 min) incorporated into the heart when hearts were perfused with either phosphatidyl-[14C]glycerol or NBD-phosphatidylglycerol. In hearts perfused with phosphatidyl-[14C]glycerol for up to 30 min the amount of radioactivity observed in phosphatidylglycerol was maximum by 5 min of perfusion and remained constant throughout the perfusion period. In the presence of 1-50 microM phosphatidylglycerol, the amount of radioactive phosphatidylglycerol incorporated into the heart was not affected. There was a time-dependent accumulation of radioactivity incorporated into cardiolipin. In addition, radioactivity was incorporated with time into lysophosphatidylglycerol. No significant amount of radioactivity was associated with other phospholipids involved in the biosynthesis of cardiolipin, including phosphatidic acid and cytidine-5'-diphosphate-1,2-diacylglycerol, precursors of cardiolipin biosynthesis via the CDP-DG pathway. We postulate that cardiac cardiolipin may be synthesized from exogenous phosphatidylglycerol independent of phosphatidylglycerol synthesized within the heart.