ObjectiveTo explore the efficacy and mechanisms of Sini San in the treatment of depression and liver injury based on gut microbiota. MethodsThirty-two male Sprague-Dawley （SD） rats were randomly divided into a normal group， model group （M）， Sini San group （MS， 2.5 g·kg^-1）， and fluoxetine group （MF， 2 mg·kg^-1）. Except for the normal group， rats in the other three groups were subjected to chronic unpredictable mild stress （CUMS）. After 8 weeks， the open-field test and sucrose preference test were conducted. Enzyme-linked immunosorbent assay （ELISA） was used to detect serum corticosterone （CORT）， adrenocorticotropic hormone （ACTH）， corticotropin-releasing factor （CRF）， lipopolysaccharide （LPS）， Zonulin， interleukin-6 （IL-6）， tumor necrosis factor-α （TNF-α）， interleukin-1β （IL-1β）， γ-aminobutyric acid （GABA） levels in the hippocampus and prefrontal cortex， and brain-derived neurotrophic factor （BDNF） levels in the hippocampus. Real-time quantitative polymerase chain reaction （Real-time PCR） was used to detect hippocampal BDNF mRNA expression. Serum alanine aminotransferase （ALT） and aspartate aminotransferase （AST） levels were measured using the ultraviolet lactate dehydrogenase method. The ultrastructure of the intestinal epithelium was observed by electron microscopy， and gut microbiota in rat feces were analyzed using 16S rDNA high-throughput sequencing. ResultsCompared with the normal group， the sucrose preference of rats in the model group was significantly reduced （P0.01）， whereas it was significantly increased in the Sini San group compared with the model group （P0.05）. Compared with the normal group， hippocampal GABA protein levels and BDNF mRNA expression in the model group were significantly decreased （P0.05）， and compared with the model group， both were significantly increased in the Sini San group （P0.05， P0.01）. Compared with the normal group， serum LPS and Zonulin levels in the model group were significantly increased （P0.05， P0.01）， and compared with the model group， Zonulin levels in the Sini San group were significantly decreased （P0.05）. No obvious changes were observed in the ultrastructure of the jejunal mucosa among groups. Compared with the normal group， widened and blurred tight junctions， sparse and shortened microvilli， and mitochondrial swelling with cristae disruption in epithelial cells were observed in the ileal and colonic mucosa of the model group， which were markedly improved in the Sini San and fluoxetine groups. The results of 16S rDNA high-throughput sequencing showed that Sini San improved CUMS-induced dysbiosis of Bacteroidetes and Proteobacteria. Correlation analysis indicated that Bacteroidetes and Proteobacteria were significantly correlated with depression-related indicators， liver function， and intestinal mucosal permeability. ConclusionSini San exerts antidepressant and hepatoprotective effects by improving Bacteroidetes and Proteobacteria and inhibiting the increase in intestinal mucosal permeability in CUMS rats.

ObjectiveTo explore the efficacy and mechanisms of Sini San in the treatment of depression and liver injury based on gut microbiota. MethodsThirty-two male Sprague-Dawley （SD） rats were randomly divided into a normal group， model group （M）， Sini San group （MS， 2.5 g·kg^-1）， and fluoxetine group （MF， 2 mg·kg^-1）. Except for the normal group， rats in the other three groups were subjected to chronic unpredictable mild stress （CUMS）. After 8 weeks， the open-field test and sucrose preference test were conducted. Enzyme-linked immunosorbent assay （ELISA） was used to detect serum corticosterone （CORT）， adrenocorticotropic hormone （ACTH）， corticotropin-releasing factor （CRF）， lipopolysaccharide （LPS）， Zonulin， interleukin-6 （IL-6）， tumor necrosis factor-α （TNF-α）， interleukin-1β （IL-1β）， γ-aminobutyric acid （GABA） levels in the hippocampus and prefrontal cortex， and brain-derived neurotrophic factor （BDNF） levels in the hippocampus. Real-time quantitative polymerase chain reaction （Real-time PCR） was used to detect hippocampal BDNF mRNA expression. Serum alanine aminotransferase （ALT） and aspartate aminotransferase （AST） levels were measured using the ultraviolet lactate dehydrogenase method. The ultrastructure of the intestinal epithelium was observed by electron microscopy， and gut microbiota in rat feces were analyzed using 16S rDNA high-throughput sequencing. ResultsCompared with the normal group， the sucrose preference of rats in the model group was significantly reduced （P<0.01）， whereas it was significantly increased in the Sini San group compared with the model group （P<0.05）. Compared with the normal group， hippocampal GABA protein levels and BDNF mRNA expression in the model group were significantly decreased （P<0.05）， and compared with the model group， both were significantly increased in the Sini San group （P<0.05， P<0.01）. Compared with the normal group， serum LPS and Zonulin levels in the model group were significantly increased （P<0.05， P<0.01）， and compared with the model group， Zonulin levels in the Sini San group were significantly decreased （P<0.05）. No obvious changes were observed in the ultrastructure of the jejunal mucosa among groups. Compared with the normal group， widened and blurred tight junctions， sparse and shortened microvilli， and mitochondrial swelling with cristae disruption in epithelial cells were observed in the ileal and colonic mucosa of the model group， which were markedly improved in the Sini San and fluoxetine groups. The results of 16S rDNA high-throughput sequencing showed that Sini San improved CUMS-induced dysbiosis of Bacteroidetes and Proteobacteria. Correlation analysis indicated that Bacteroidetes and Proteobacteria were significantly correlated with depression-related indicators， liver function， and intestinal mucosal permeability. ConclusionSini San exerts antidepressant and hepatoprotective effects by improving Bacteroidetes and Proteobacteria and inhibiting the increase in intestinal mucosal permeability in CUMS rats.

ObjectiveTo explore the mechanisms of Yangjing Tongluo prescription （YJTL） in the treatment of intrauterine adhesion （IUA） from the perspective of oxidative stress mediated by the Kelch-like ECH-associated protein 1/nuclear factor erythroid 2-related factor 2/heme oxygenase-1 （Keap1/Nrf2/HO-1） signaling pathway. MethodsA total of 48 rats with normal estrous cycles were selected and randomly divided into a normal group （n=8） and a modeling group （n=40）. An IUA rat model was established using a dual-injury method combining surgical curettage and infection. Eight rats were randomly selected from the modeling group for a pilot experiment to confirm successful model establishment. After successful modeling， the remaining 32 rats were randomly divided into a model group， a low-dose YJTL group （YJTL-L）， a high-dose YJTL group （YJTL-H）， and a Progynova group. Rats in the normal and model groups were administered purified water （15 mL·kg^-1） by gavage daily， while rats in the YJTL-L， YJTL-H， and Progynova groups received YJTL at doses of 6.43 and 12.86 g·kg^-1 and Progynova at 2.06 × 10^-4 g·kg^-1， respectively， for 14 consecutive days. The general condition， uterine morphology， and uterine index of the rats were monitored. Histopathological changes in uterine tissue were observed using hematoxylin-eosin （HE） staining. Serum levels of reactive oxygen species （ROS） and glutathione peroxidase （GSH-Px） were measured by enzyme-linked immunosorbent assay （ELISA）. Protein expression levels of Keap1， Nrf2， and HO-1 in endometrial tissue were detected by Western blot. Immunofluorescence （IF） was used to assess the distribution of Nrf2 and HO-1， as well as the expression of Nrf2 in the cytoplasm and nucleus. ResultsCompared with the normal group， rats in the model group exhibited poor mental status and reduced mobility， markedly edematous and tortuous uterine morphology， decreased gland number， and inflammatory reactions in the endometrium， along with an increased uterine organ index （P<0.05）. Serum ROS levels were significantly increased （P<0.05）， while serum GSH-Px levels were significantly decreased （P<0.05）. In endometrial tissue， Keap1 protein expression was increased （P<0.05）， whereas Nrf2 and HO-1 protein expression was decreased. Mild nuclear translocation of Nrf2 was observed， accompanied by increased relative fluorescence intensity of nuclear Nrf2 and decreased relative fluorescence intensity of cytoplasmic HO-1. Compared with the model group， all treatment groups showed varying degrees of improvement in the above symptoms and pathological changes. Serum ROS levels were reduced （P<0.05）， serum GSH-Px levels were increased （P<0.05）， Keap1 protein expression in endometrial tissue was decreased， and Nrf2 and HO-1 protein expression was increased in a dose-dependent manner （P<0.05）. Notably， significant nuclear translocation of Nrf2 was observed， with correspondingly increased relative fluorescence intensity of nuclear Nrf2 and enhanced relative fluorescence intensity of cytoplasmic HO-1. ConclusionYJTL may enhance antioxidant capacity and repair oxidative damage to the endometrial basal layer by regulating the Keap1/Nrf2/HO-1 signaling pathway.

ObjectiveTo investigate the gene expression sequence and molecular mechanisms in the local microenvironment during the subacute to chronic phases (1-28 days) in mouse models of spinal cord compression injury and hemisection spinal cord injury, thereby revealing the molecular characteristics of spinal cord repair and providing a theoretical basis for selecting therapeutic targets for spinal cord injury. MethodsThirty-six 8-9-week-old SPF-grade ICR mice were randomly divided into three groups (n=12 per group): sham-operated control (CTR) group, hemisection spinal cord injury (HSCI) group, and spinal cord compression injury (SCC) group. Mice in the CTR group underwent the same surgical preparation and anesthesia, followed by a dorsal midline incision at the T₉-T₁₀ segment. After layer-by-layer dissection and removal of the corresponding lamina, the spinal cord dura mater was fully exposed and kept intact. The cord was exposed to air for 10 minutes (matching the duration of the compression injury group), during which any instrument contact with the cord was avoided. The incision was then irrigated and sutured. The HSCI group underwent a 70% transection of the T₉ spinal cord segment using micro-instruments to establish a hemisection spinal cord injury model. The SCC group underwent sustained compression of the T₁₀ spinal cord segment for 10 minutes using a self-made compressor (a 30 g solid small iron bar) to establish a spinal cord compression injury model. Motor function recovery was assessed using the modified Basso-Beattie-Bresnahan (BBB) score on postoperative days 1, 3, 7, 14, 21, and 28. On days 7 and 14 post-operation, mice were anesthetized, and the injured spinal cord segments were harvested. The evolution of specific molecular networks in the spinal cord injury mouse models was analyzed via RNA sequencing (RNA-Seq) and enrichment analysis, and the expression of key genes was verified using real time fluorogenic quantitative PCR. ResultsBBB scores indicated that motor function recovery in the SCC group was significantly better than that in the HSCI group, with BBB scores showing a continuously increasing trend and remaining higher than those in the HSCI group over the 4-week period (P <0.001). Gene ontology （GO)and Kyoto Encyclopedia of Genes and Genomes （KEGG） enrichment analyses based on RNA-Seq differentially expressed genes revealed that, compared to the CTR group, genes related to the extracellular matrix were significantly up-regulated (P<0.05), while genes related to axon guidance were significantly down-regulated (P <0.05) in the SCC group on day 7 post-operation. On day 21, genes involved in immune regulation and the retinol signaling pathway were significantly activated in the SCC group (P<0.05). In contrast, in the HSCI group, genes associated with inflammation and immune response were significantly up-regulated (P<0.001), while genes related to neuronal differentiation and synapse formation were significantly down-regulated (P <0.001) on day 7. On day 21, genes related to cell-matrix junctions and N-methyl-D-aspartate receptors were significantly up-regulated (P<0.001) in the HSCI group. Furthermore, compared to the SCC group, the HSCI group exhibited different pathway enrichment characteristics in GO and KEGG analyses on days 7 and 21 post-injury. On day 7, genes involved in the NOD-like receptor signaling pathway and the complement and coagulation cascades were significantly up-regulated in the HSCI group (P<0.001). On day 21, genes related to the extracellular matrix-receptor interaction and the neuroactive ligand-receptor interaction pathways were significantly activated (P<0.001). Finally, real time fluorogenic quantitative PCR validation results were highly consistent with the RNA-Seq results, further confirming the differential expression trends of key genes between the SCC and HSCI groups. ConclusionThe SCC and HSCI injury models may drive distinct repair pathways: the preservation of some axons in the SCC model predisposes it toward tissue repair, whereas the HSCI model requires the coordination of more complex molecular networks to achieve a new equilibrium. This finding further deepens the understanding of the heterogeneous regulatory mechanisms underlying spinal cord injury.

[摘 要] 目的：探讨高良姜素（Gal）调控AMPK/mTOR/ULK1信号通路对胃癌细胞凋亡和自噬的影响及其机制。方法：将胃癌NCI-N87细胞分为对照组、多索吗啡（DM）组、Gal低剂量（Gal-L）组、Gal高剂量（Gal-H）组、Gal-H + DM组。采用MTT法、流式细胞术、划痕愈合实验和Transwell实验分别检测各组细胞的增殖、凋亡、迁移和侵袭能力，WB法检测PCNA、C-caspase-3、免疫逃逸相关蛋白（B7H1）、EMT和AMPK/mTOR/ULK1信号通路蛋白的表达水平。建立裸鼠NCI-N87细胞移植瘤模型，观察Gal和5-FU对移植瘤的抑制效果。结果：与对照组比较，DM组NCI-N87细胞增殖活性、划痕愈合率和侵袭细胞数、N-cadherin、vimentin、PCNA、B7H1、p62和p-mTOR/mTOR蛋白表达均显著升高（均P < 0.05），细胞凋亡率、C-caspase-3、E-cadherin、LC3Ⅱ/LC3Ⅰ、p-AMPK/AMPK和p-ULK1/ULK1蛋白表达均显著降低（均P < 0.05）；Gal-L组和Gal-H组NCI-N87细胞的增殖活性、划痕愈合率和侵袭细胞数、N-cadherin、vimentin、PCNA、B7H1、p62和p-mTOR/mTOR蛋白表达均显著降低（均P < 0.05），细胞凋亡率、C-caspase-3、E-cadherin、LC3Ⅱ/LC3Ⅰ、p-AMPK/AMPK和p-ULK1/ULK1蛋白表达均显著升高（均P < 0.05）；DM可部分逆转Gal对NCI-N87细胞恶性生物学行为的抑制作用（P < 0.05）；与对照组比较，Gal组和5-FU组裸鼠移植瘤体积和质量均显著降低，肿瘤组织细胞凋亡率显著升高（P < 0.05）。结论：Gal可促进胃癌NCI-N87细胞自噬和凋亡，抑制其增殖、迁移和侵袭，可能与激活AMPK/mTOR/ULK1信号通路有关。

ObjectiveTo explore the improving effect of Huangqi Chifengtang（HCT） on atherosclerosis（AS）， and elucidate its mechanism in relation to adenosine monophosphate-activated protein kinase（AMPK）/peroxisome proliferator-activated receptor α（PPARα） signaling pathway and nucleotide-binding oligomerization domain（NOD）-like receptor thermal protein domain associated protein 3（NLRP3） inflammasome. MethodsEight C57BL/6J mice were set as the normal group， and 32 ApoE^-/- mice were randomly divided into the model group， the positive drug group（atorvastatin， 5 mg·kg^-1·d^-1）， HCT low- and high-dose groups（1.95， 3.90 g·kg^-1·d^-1）. ApoE^-/- mice were fed with high-fat and high-cholesterol feed to establish an AS mouse model. After modeling， they were orally administered corresponding dose of drugs for 28 days， while the normal and model groups received an equal volume of physiological saline via oral gavage. Hematoxylin-eosin（HE） staining was used to observe the pathological status of the aorta and liver in mice， Biochemical testing and enzyme-linked immunosorbent assay（ELISA） were used to detect the levels of total cholesterol（TC）， triglycerides（TG）， low-density lipoprotein cholesterol（LDL-C）， alanine aminotransferase（ALT）， aspartate aminotransferase（AST）， C-reactive protein（CRP）， interleukin（IL）-1β， IL-18 in the serum， as well as superoxide dismutase（SOD）， malondialdehyde（MDA）， and reduced glutathione（GSH） in the liver. Real-time fluorescence quantitative polymerase chain reaction（Real-time PCR） was used to measure the mRNA expression levels of NLRP3， apoptosis-associated speck-like protein（ASC）， cysteinyl aspartate specific proteinase-1（Caspase-1）， Toll-like receptor 4（TLR4） in the aorta， and fatty acid synthase（FAS）， stearoyl-CoA desaturase 1（SCD1）， PPARα， and carnitine palmitoyltransferase 1A（CPT1A） in the liver. Immunohistochemistry was used to determine the protein expressions of NLRP3， Caspase-1， and ASC in the aorta， and Western blot was used to measure the protein expressions of AMPK， p-AMPK， sterol regulatory element binding protein-1c（SREBP-1c）， CPT1A， and FAS in the liver. ResultsCompared with the normal group， the model group showed a significant increase in lipid plaque deposition in the aorta and lipid accumulation in the liver， the levels of TC， TG， LDL-C， AST， ALT， IL-1β， IL-18 and CRP in the serum were significantly increased（P<0.01）， and the mRNA and protein expressions of aortic TLR4， NLRP3， Caspase-1 and ASC were significantly upregulated（P<0.01）. The levels of SOD and GSH in the liver were significantly reduced， while the level of MDA was significantly increased（P<0.01）. The mRNA expressions of FAS and SCD1 in the liver were significantly downregulated， while the mRNA expressions of PPARα and CPT1A were significantly upregulated. The protein expressions of p-AMPK/AMPK and CPT1A in the liver were significantly reduced， while the expressions of SREBP-1c and FAS proteins were significantly increased（P<0.01）. Compared with the model group， the low- and high-dose HCT groups showed significant improvements in aortic plaques and hepatic lipid deposition. The levels of TC， LDL-C， AST， IL-1β and IL-18 in the serum of the low-dose HCT group， as well as TC， TG， LDL-C， AST， ALT， IL-1β， IL-18 and CRP in the serum of the high-dose HCT group， were significantly reduced（P<0.01）. The mRNA expressions of TLR4， NLRP3 and Caspase-1 in the aorta of the low-dose HCT group， as well as TLR4， NLRP3， Caspase-1 and ASC in the aorta of the high-dose HCT group， were significantly downregulated（P<0.01）. The protein expressions of Caspase-1 and ASC in the aorta of the low-dose HCT group， as well as NLRP3， Caspase-1 and ASC in the high-dose HCT group， were significantly downregulated（P<0.01）. The levels of SOD and GSH in the liver of the low- and high-dose HCT groups were significantly increased， while the level of MDA in the high-dose HCT group was significantly decreased（P<0.05， P<0.01）. In the HCT-treated group， the mRNA expressions of FAS and SCD1 in the liver were significantly upregulated， while the mRNA expressions of PPARα and CPT1A were significantly downregulated， the protein expressions of p-AMPK/AMPK and CPT1A in the liver were significantly increased， while the protein expressions of SREBP-1c and FAS were significantly decreased（P<0.05， P<0.01）. ConclusionHCT can improve lipid metabolism by activating the AMPK/PPARα pathway and inhibit NLRP3 inflammasome-mediated inflammatory responses， thereby reducing hepatic lipid deposition and AS plaque formation.

Stroke is the leading cause of death and disability among adults in China， and its common complications include digestive system abnormalities， cognitive impairment， depression， stroke-associated pneumonia， and hemiplegia. The combination of traditional Chinese and Western medicine has great potential in treating post-stroke complications. Xinglou Chengqitang （XLCQT） is a representative prescription of alleviating the disease in the upper part by treating the lower part. It has definite therapeutic effect and high safety. Clinically， XLCQT is often used to treat stroke and its complications. However， the quantity and quality of clinical trials of XLCQT in treating post-stroke complications need to be improved. Additionally， since the basic research is weak， the material basis and multi-target mechanism for the efficacy of this prescription are unknown. This article reviews XLCQT in terms of the pharmacodynamic basis， medicinal properties， safety evaluation， and progress in clinical research and mechanisms in treating post-stroke complications. This article summarizes 22 key active ingredients of XLCQT in treating acute stroke complicated with syndrome of phlegm heat and fu-organ excess. Among these key active ingredients， resveratrol， kaempferol， luteolin， chrysoeriol， apigenin， （+）-catechin， and adenosine have good pharmacokinetic properties and high bioavailability. The mechanisms of XLCQT in treating post-stroke complications are complex， including inflammatory response， brain-gut axis， hypothalamic-pituitary-adrenal （HPA） axis， intestinal flora， neurotrophic factors， autophagy， oxidative stress， and free radical damage. This review helps to deeply understand the pharmacodynamic basis and mechanisms of XLCQT in treating post-stroke complications and provides a theoretical basis for the clinical application of XLCQT against post-stroke complications and the development of drugs.

ObjectiveTo introduce visual teaching into the course design of medical humanistic care based on the concept of implementation science， evaluate the teaching implementation effect and feedback， and provide references for optimizing course teaching outcomes and improving students’ humanistic care competence. MethodsA visual teaching program for medical humanistic care was designed， with key steps including clarifying teaching objectives， content， methods， and curriculum assessment. This program was implemented in the medical humanistic care course teaching involving 50 elective students. Multi-dimensional evaluation of teaching effectiveness was conducted through course grades， visual teaching evaluation， and humanistic workshop assessment， combined with inductive content analysis of students’ learning experiences in the workshops. ResultsThe 50 students achieved above-average course grades （89.60±3.41） and demonstrated high satisfaction with the overall course and visual teaching. All the 6 groups obtained relatively high scores in the medical humanistic care workshops. Four themes were extracted， namely， enhancing humanistic care competencies， deepening familial and interpersonal relationships， realizing emotional expression and self-growth， and strengthening integration of humanistic care concepts with practice. ConclusionThe teaching of medical humanistic care course has achieved favorable effects， which contributes to deepening students’ understanding of humanistic care and enhancing their humanistic care competence. Students demonstrate high levels of recognition and satisfaction with the course.

Objective To investigate the current distribution of radiotherapy resources in Gansu Province, evaluate the equity of resource allocation, and provide a scientific basis for optimizing regional resource allocation. Methods A questionnaire survey was carried out to assess radiotherapy resources in medical institutions across Gansu Province, China. The equity of radiotherapy resource distribution and associated disparities were assessed using the Gini coefficient, Lorenz curve, and Theil index. Results A total of 23 medical institutions in Gansu Province provided radiotherapy services, comprising 39 radiotherapy devices and 438 professionals, of whom medical physicists accounted for 16.9%. The radiotherapy frequency was 0.47 cases per thousand population. The Gini coefficients for radiotherapy resource distribution ranged from 0.38 to 0.56 by population and from 0.52 to 0.70 by geography. The Theil index for radiotherapy resources ranged from 1.36 to 3.67. Conclusion Radiotherapy resources in Gansu Province were insufficient, and the capacity of radiotherapy service was suboptimal. The equity of radiotherapy resource allocation by geography was worse than that by population. Therefore, it is imperative to address the shortage of radiotherapy resources, strengthen the professional workforce, enhance the capacity radiotherapy service and resource utilization, optimize resource allocation, and promote regional equity in radiotherapy provision in Gansu Province.

Objective To preliminarily investigate the safety and efficacy of donor pancreas needle biopsy in simultaneous pancreas-kidney transplantation. Methods Clinical data of 7 cases undergoing donor pancreas biopsy were collected retrospectively. All cases underwent donor pancreas biopsy before or during simultaneous pancreas-kidney transplantation. Frozen section or paraffin sectioning techniques were used for tissue preparation, and hematoxylin-eosin and Masson staining were performed to histologically evaluate the donor pancreas. The quality of donor pancreas was comprehensively assessed by combining histological findings with the donor's clinical data. Postoperative follow-up data of 5 simultaneous pancreas-kidney transplant recipients were collected to summarize the safety of donor pancreas biopsy and the prognosis of transplant recipients. Results The 7 pancreas donors were aged 28 to 62 years, with a body mass index ranging from 20.76 to 27.68 kg/m². Liver ultrasound indicated fatty liver in 3 cases, while pancreatic ultrasound did not reveal any significant abnormalities. Among them, biopsy was performed on 2 donors after completion of pancreatic procurement and processing, and the frozen section histology showed moderate acute pancreatitis changes (edema of acinar cells, necrosis and inflammatory cell infiltration). Combined with a serum amylase level elevated more than 3 times the upper limit of normal value, these two donor pancreases were finally discarded. The remaining 5 cases underwent biopsy immediately after pancreatic vascular anastomosis during simultaneous pancreas-kidney transplantation, and histological evaluation was performed on paraffin-embedded sections. No biopsy-related complications (such as bleeding, pancreatic fistula, etc.) occurred after transplantation. One recipient died of severe infection 2 months after transplantation, while the other 4 recipients were followed up for more than 5 years, with well-functioning transplant kidneys and pancreases. Conclusions Donor pancreas biopsy is relatively safe, and the risk of biopsy-related complications after transplantation is controllable. Comprehensive assessment of donor pancreas quality by combining histological evaluation with the donor's clinical indicators is conducive to improving the accuracy of donor pancreas selection and organ utilization.