Characteristics and Significance of Tertiary Lymphoid Structures Based on Molecular Subtypes in Endometrial Cancer.

The purpose of this study is to investigate the characteristics and significance of tertiary lymphoid structures (TLSs) in endometrial cancer (EC) based on molecular subtypes. A total of 220 patients with EC were retrospectively enrolled, including 20 with polymerase epsilon ultramutated (POLE-mut), 63 with mismatch repair deficient, 32 with p53 abnormal, and 105 with no specific molecular profile. The presence and maturity of TLSs were determined by immunohistochemical markers (CD3, CD20, CD21, and Bcl6). Disease-free survival served as the endpoint event. TLSs were found in 91 out of 220 patients (41.1%), with 68 located in peritumoral tissues and 37 exhibiting well-formed germinal center structures. The presence and different maturity of TLSs were closely associated with tumor-infiltrating lymphocytes and the programmed cell death ligand-1 expression. Moreover, TLSs displayed heterogeneity across different molecular subtypes. Notably, the TLSs, tumor-infiltrating lymphocytes, and expression of the programmed cell death ligand-1 were significantly enriched in POLE-mut EC. Multivariate logistic regression analysis showed the presence of TLSs (odds ratio: 3.483, 95% CI: 1.044-11.623, P = 0.042) as a potential predictor of POLE-mut EC. Kaplan-Meier survival curves revealed that molecular subtypes significantly stratified prognosis in patients with EC (P = 0.002), whereas TLSs did not. Multivariate Cox regression analysis indicated that The International Federation of Gynecology and Obstetrics stage and Ki-67 expression were independent prognostic factors affecting disease-free survival in patients with EC, and TLSs were not included. In conclusion, TLSs in EC exhibit heterogeneity based on molecular subtypes, necessitating further exploration to determine their clinical application value.

Concurrent neoadjuvant chemotherapy and estrogen deprivation in patients with estrogen receptor-positive, human epidermal growth factor receptor 2-negative breast cancer (CBCSG-036): A randomized, controlled, multicenter trial.

BACKGROUND: The current randomized, controlled, multicenter clinical trial was conducted to investigate the efficacy of concurrent neoadjuvant chemotherapy (NCT) and estrogen deprivation in patients with estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer. METHODS: Eligible patients with AJCC stage IIB to stage IIIC, ER-positive, HER2-negative breast cancer were enrolled and randomly assigned to receive NCT with or without estrogen deprivation. The primary endpoint was the objective response rate (ORR). RESULTS: A total of 249 patients were assigned to either neoadjuvant chemoendocrine therapy (NCET) (125 patients) or the NCT group (124 patients). In the intention-to-treat analysis, the ORR was found to be significantly higher in the NCET group compared with the NCT group (84.8% vs 72.6%; odds ratio, 2.11 [95% CI, 1.13-3.95; P = .02). The efficacy of NCET was more prominent in tumors with a higher Ki-67 index (>20%), with an ORR of 91.2% reported in the NCET group versus 68.7% in the NCT group (P = .001). The pathologic complete response and pathological response rates did not differ significantly between the 2 groups. Although there was no significant difference with regard to progression-free survival (PFS) between the 2 groups (P = .188), patients with a higher baseline Ki-67 index appeared to derive a greater PFS benefit from NCET (2-year PFS rate of 91.5% in the NCET group vs 76.5% in the NCT group; P = .058). Adding endocrine agents to NCT did not result in significant differences in adverse events (grade 3 or 4; graded according to National Cancer Institute Common Terminology Criteria for Adverse Events [version 3.0]) between the 2 groups. CONCLUSIONS: The addition of estrogen deprivation to NCT appears to improve the clinical response in patients with ER-positive, HER2-negative breast cancer, especially for those individuals with a higher Ki-67 index. Patients with a higher Ki-67 index might derive more PFS benefit from concurrent neoadjuvant treatment.

Somatic point mutations occurring early in development: a monozygotic twin study.

The identification of somatic driver mutations in cancer has enabled therapeutic advances by identifying drug targets critical to disease causation. However, such genomic discoveries in oncology have not translated into advances for non-cancerous disease since point mutations in a single cell would be unlikely to cause non-malignant disease. An exception to this would occur if the mutation happened early enough in development to be present in a large percentage of a tissue's cellular population. We sought to identify the existence of somatic mutations occurring early in human development by ascertaining base-pair mutations present in one of a pair of monozygotic twins, but absent from the other and assessing evidence for mosaicism. To do so, we genome-wide genotyped 66 apparently healthy monozygotic adult twins at 506 786 high-quality single nucleotide polymorphisms (SNPs) in white blood cells. Discrepant SNPs were verified by Sanger sequencing and a selected subset was tested for mosaicism by targeted high-depth next-generation sequencing (20 000-fold coverage) as a surrogate marker of timing of the mutation. Two de novo somatic mutations were unequivocally confirmed to be present in white blood cells, resulting in a frequency of 1.2×10(-7) mutations per nucleotide. There was little evidence of mosaicism on high-depth next-generation sequencing, suggesting that these mutations occurred early in embryonic development. These findings provide direct evidence that early somatic point mutations do occur and can lead to differences in genomes between otherwise identical twins, suggesting a considerable burden of somatic mutations among the trillions of mitoses that occur over the human lifespan.

Two new sesquiterpene glycosides from the stems of Dendrobium henanense and their anti-inflammatory activity.

Two new sesquiterpene glycosides, 8α,12,15ß-trihydroxycopacamphan-15-O-ß-D-glucopyranoside (1) and dendrobiumane C-11-O-ß-D-glucopyranoside (2), along with three known terpenoids (3-5) were isolated from the aerial stems of Dendrobium henanense. Their structures were elucidated based on NMR-spectroscopic and HR-MS analyses. All compounds could reduce the levels of NO, TNF-α and IL-1ß in LPS-induced RAW264.7 cells with IC50 values ranging from 10.37 to 34.55 µΜ.

Subtalar distraction osteogenesis for posttraumatic arthritis following intra-articular calcaneal fractures.

BACKGROUND: The most common treatment for old calcaneal fractures accompanied by subtalar joint injury is the use of subtalar in situ arthrodesis and subtalar distraction bone-block arthrodesis or osteotomy. This article describes the introduction of a novel surgical treatment, gradual subtalar distraction with external fixation and restoration of the calcaneal height, and presents an assessment of its efficacy. METHODS: The protruding lateral calcaneus and the articular surfaces and subchondral bone of the posterior facet of the subtalar joint were surgically removed. An external fixator, attached with 2 pins in the subcutaneous tibia and 2 pins in the posterolateral calcaneus, was used to fix the subtalar joint for 7 to 10 days followed by gradual subtalar distraction at 1 mm/d. The lengthening procedure was stopped when the calcaneal height was restored according to radiography. The external fixator was removed after bone fusion. Seven cases of old calcaneal fractures accompanied by severe subtalar joint injury (8 feet) were treated using this method. Average follow-up was 14.3 months (range, 7-36 months). RESULTS: In all 7 cases (1 case of both feet), the postoperative wound healed primarily. The calcaneal heights of all 8 feet were partially restored. Subtalar joint bone fusion was completed within 4 to 6 months after the operation. The average preoperative American Orthopedic Foot & Ankle Society (AOFAS) hindfoot score was 25.3, and the average postoperative AOFAS score was 76.3. CONCLUSION: Subtalar distraction osteogenesis with external fixation was a novel and effective method for the treatment of old calcaneal fractures accompanied by severe subtalar joint injury in this small group of patients. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Clinical feasibility and oncological safety of non-radioactive targeted axillary dissection after neoadjuvant chemotherapy in biopsy-proven node-positive breast cancer: a prospective diagnostic and prognostic study.

BACKGROUND: Targeted axillary dissection (TAD) includes biopsy of clipped lymph node and sentinel lymph nodes. However, clinical evidence regarding clinical feasibility and oncological safety of non-radioactive TAD in a real-world cohort remains limited. METHODS: In this prospective registry study, patients routinely underwent clip insertion into biopsy-confirmed lymph node. Eligible patients received neoadjuvant chemotherapy followed by axillary surgery. Main endpoints included the false-negative rate (FNR) of TAD and nodal recurrence rate. RESULTS: Data from 353 eligible patients were analyzed. After completion of neoadjuvant chemotherapy, 85 patients directly proceeded to axillary lymph node dissection (ALND), furthermore, TAD with or without ALND was performed in 152 and 85 patients, respectively. Overall detection rate of clipped node was 94.9% (95% CI, 91.3-97.4%) and FNR of TAD was 12.2% (95% CI, 6.0-21.3%) in our study, with FNR decreasing to 6.0% (95% CI, 1.7-14.6%) in initially cN1 patients. During a median follow-up of 36.6 months, 3 nodal recurrences occurred (3/237 with ALND; 0/85 with TAD alone), with a 3-year freedom-from-nodal-recurrence rate of 100.0% among the TAD-only patients and 98.7% among the ALND patients with axillary pathologic complete response ( P =0.29). CONCLUSIONS: TAD is feasible in initially cN1 breast cancer patients with biopsy-confirmed nodal metastases. ALND can safely be foregone in patients with negativity or a low volume of nodal positivity on TAD, with a low nodal failure rate and no compromise of 3-year recurrence-free survival.

Bromelain ameliorates the wound microenvironment and improves the healing of firearm wounds.

BACKGROUND: In a previous study, we proposed a new therapy using topical bromelain as a supplement to simple wound-track incision for the debridement of firearm wounds. This enzymatic debridement greatly simplified the management of high-velocity gunshot wounds in a pig model, and bromelain was confirmed to improve wound healing. The purpose of the present study was to investigate the effect of bromelain on the microenvironment of firearm wounds. METHODS: Sixteen Chinese landrace pigs wounded by high-velocity projectiles were divided randomly into four groups: wound incision (group I), incision + bromelain (group IB), wound excision (group E), and control. Blood perfusion, oxygen partial pressure (pO(2)), and the content of tumor necrosis factor (TNF)-α and transforming growth factor (TGF)-ß in wound-track tissue were measured. Wound healing was also noted. RESULTS: The recovery of blood perfusion in tissue and pO(2) in wound tracks was significantly more rapid in group IB and group E than in group I and control. The tissue level of TNF-α was significantly lower in group IB than in group I and control 48 h and 72 h post-wounding, and was lower than in group E 48 h post-wounding. The tissue level of TGF-ß in group IB was sustained at a significantly higher level than in the other three groups. Wound healing time was also shorter in group IB. CONCLUSIONS: Enzymatic debridement using topical bromelain in incised wound tracks accelerates the recovery of blood perfusion, pO(2) in wound tissue, controls the expression of TNF-α and raises the expression of TGF-ß.

Debriding effect of bromelain on firearm wounds in pigs.

BACKGROUND: Wound excision is the standard treatment for firearm wounds. However, achieving a satisfactory curative effect is difficult because of the traumatic mechanism of high-velocity projectiles. We propose a new therapy by using topical bromelain as a supplement to wound incision for the debridement of firearm wounds. We clarified the debriding effect of bromelain on firearm wounds in pigs. METHODS: In vitro, muscle tissues around the wound track and normal muscle were incubated in bromelain solutions of different concentrations. Tissue hydrolization was estimated by measuring tissue weight and the release of total amino acids. In vivo, the hind limbs of 15 pigs were wounded with high-velocity projectiles. Five groups were classified as follows: wound excision (E), wound incision (I), bromelain (B), incision + bromelain (IB), and control (C). Debriding effectiveness was estimated using bacterial content, histopathologic examination, and wound healing time. RESULTS: In vitro, hydrolization of wound tissue was significantly more intensive than that of normal tissue. Bromelain solution (10 mg/mL) hydrolyzed wound tissue rapidly with minimal proteolysis of normal tissue. In vivo, the wound-track bacterial content of group IB was similar to that of group E and was significantly lower than that of groups I, B, and C. The wound healing time of group IB was also shorter. CONCLUSIONS: Bromelain is effective in the debridement of uncomplicated firearm wounds if used as a supplement to simple wound incision. This new therapy shows notable advantages over conventional surgical debridement as it greatly simplifies the procedures.

Effects of grazing intensities on functional traits of Cleistogenes squarrosa in a typical grassland of Inner Mongolia, China.

We examined the response of 11 functional traits of Cleistogenes squarrosa, including plant height and clump width, to the grazing of different intensity (no grazing; twice grazing in May and July; five grazing in the whole growing season). After five-year treatments, the number of reproductive branches, plant height, stem quality, specific leaf area and total leaf area were significantly reduced. Such reduction was significantly increased with the increases of grazing intensity. Under the treatments of grazing in May and July, the declines of each index were 61.7%, 21.5%, 33.3%, 21.6% and 26.7%, respectively; and the declines in the treatment of whole growing season grazing were 75.7%, 24.7%, 46.7%, 28.5% and 43.7%, respectively. The number of vegetative branches, number of leaf, total leaf area, stem quality, total leaf quality and clump width of the C. squarrosa had a synergistic relationship with aboveground biomass of the whole clump under different grazing intensities. The number of vegetative branches was significantly positively correlated with stem quality and total leaf quality. C. squarrosa had a dwarf-dense branching strategy to avoid grazing. The reduction of grazing intensity would be conducive to maintaining the stability of functional traits.

Prior Local or Systemic Treatment: A Predictive Model Could Guide Clinical Decision-Making for Locoregional Recurrent Breast Cancer.

INTRODUCTION: Locoregional recurrent breast cancer indicates poor prognosis. No solid prediction model is available to predict prognosis and guide clinical management. Prior local treatment or systemic treatment remains controversial. METHODS: Locoregional recurrent breast cancer patients operated in Fudan University Shanghai Cancer Center were enrolled as a training cohort. An external validation cohort included breast cancer patients after locoregional recurrence from Ruijin Hospital, Shanghai Jiaotong University. A nomogram predicting overall survival after locoregional recurrence was established using multivariable Cox regression analysis while internal and external validation were performed to evaluate its calibration and discrimination. RESULTS: Overall, 346 and 96 breast cancer patients were included in the training cohort and the validation cohort separately. A nomogram was developed, including age, neoadjuvant chemotherapy, breast surgery, pathology type, tumor size, lymph node status, hormonal receptor and Her-2 status, disease-free interval, and sites of locoregional recurrence. It had modest calibration and discrimination in the training cohort, internal validation and external validation (concordance index: 0.751, 0.734 and 0.722, respectively). The nomogram classified 266 and 80 patients into low and high-risk subgroups with distinctive prognosis. Local treatment after locoregional recurrence was associated with improved overall survival in low-risk group (P = 0.011), while systemic therapies correlated with better outcomes only in high-risk group (P < 0.001). CONCLUSION: A nomogram based on clinicopathological factors can predict prognosis and identify low and high-risk patients. Local treatment is a prior choice for low-risk patients whereas systemic treatment needs to be considered for high-risk patients, warranting further validation and exploration.

MYC suppresses STING-dependent innate immunity by transcriptionally upregulating DNMT1 in triple-negative breast cancer.

BACKGROUND: Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer and lacks definite treatment targets. Tumor immune microenvironment (TIME) heterogeneity has a profound impact on the immunotherapy response. Tumors with non-inflamed TIME derive limited benefit from immunotherapy. However, what drives the formation of the non-inflamed TIME in TNBC remains unclear. METHODS: Using our multiomics database of TNBC, we conducted an analysis to explore the key genomic events driving the formation of the non-inflamed TIME in TNBC. In vitro and in vivo studies further revealed potential mechanisms and the efficacy of combination treatment with immunotherapy. RESULTS: With transcriptomic and genomic data, we systematically analyzed the TIME of TNBC and revealed that the classical basal-like subtype of TNBC consisted of two distinct microenvironment phenotypes, defined as the 'inflamed' and 'non-inflamed' subtypes. We performed further screening and demonstrated that MYC amplification and overexpression led to low immune infiltration and cytolytic activity in TIME. Mechanistically, MYC bound to DNMT1 promoter and activated DNMT1 transcription in TNBC cells, thus suppressing the Cyclic GMP-AMP synthase (cGAS)-STING pathway via an epigenetic regulatory way. In MYC-overexpressing TNBC, decitabine, an Food and Drug Administration (FDA)-approved DNA methyltransferase inhibitor, converted tumors from non-inflamed to inflamed tumors by enhancing T cell infiltration. Furthermore, the combination of decitabine with programmed cell death protein 1 (PD-1) inhibitor reversed T cell exhaustion and improved T cell function in mouse models, which elicited potent antitumor activity in MYC-overexpressing TNBC. CONCLUSIONS: Our work elucidates that the classic oncogene MYC induces immune evasion by repressing innate immunity. Furthermore, we provide a rationale for combining DNA methyltransferase inhibition with immunotherapy for the treatment of MYC-overexpressing TNBC.

GCH1 induces immunosuppression through metabolic reprogramming and IDO1 upregulation in triple-negative breast cancer.

PURPOSE: Regulatory T cells (Tregs) heavily infiltrate triple-negative breast cancer (TNBC), and their accumulation is affected by the metabolic reprogramming in cancer cells. In the present study, we sought to identify cancer cell-intrinsic metabolic modulators correlating with Tregs infiltration in TNBC. EXPERIMENTAL DESIGN: Using the RNA-sequencing data from our institute (n=360) and the Molecular Taxonomy of Breast Cancer International Consortium TNBC cohort (n=320), we calculated the abundance of Tregs in each sample and evaluated the correlation between gene expression levels and Tregs infiltration. Then, in vivo and in vitro experiments were performed to verify the correlation and explore the underlying mechanism. RESULTS: We revealed that GTP cyclohydrolase 1 (GCH1) expression was positively correlated with Tregs infiltration and high GCH1 expression was associated with reduced overall survival in TNBC. In vivo and in vitro experiments showed that GCH1 increased Tregs infiltration, decreased apoptosis, and elevated the programmed cell death-1 (PD-1)-positive fraction. Metabolomics analysis indicated that GCH1 overexpression reprogrammed tryptophan metabolism, resulting in L-5-hydroxytryptophan (5-HTP) accumulation in the cytoplasm accompanied by kynurenine accumulation and tryptophan reduction in the supernatant. Subsequently, aryl hydrocarbon receptor, activated by 5-HTP, bound to the promoter of indoleamine 2,3-dioxygenase 1 (IDO1) and thus enhanced the transcription of IDO1. Furthermore, the inhibition of GCH1 by 2,4-diamino-6-hydroxypyrimidine (DAHP) decreased IDO1 expression, attenuated tumor growth, and enhanced the tumor response to PD-1 blockade immunotherapy. CONCLUSIONS: Tumor-cell-intrinsic GCH1 induced immunosuppression through metabolic reprogramming and IDO1 upregulation in TNBC. Inhibition of GCH1 by DAHP serves as a potential immunometabolic strategy in TNBC.

Comparison of interface contact profiles of a new minimum contact locking compression plate and the limited contact dynamic compression plate.

In this study, we investigated whether or not a new minimum contact locking compression plate (MC-LCP) can provide advantages over the limited contact dynamic compression plate (LC-DCP) in the context of interface contact area and force. Six matched pairs of cadaveric bones were used for each of three bone types of the humerus, radius and ulna. For each bone type, one of two bone plates was fixed to either of two matched cadaveric bones at the middle of the diaphysis. The interface contact area and force of the plate fixed to three types of human cadaveric bones were evaluated using Fuji prescale pressure sensitive film. Data were quantitated using computer-assisted image analysis. Results showed that the average force between the MC-LCP and humerus or radius was about half of that of the LC-DCP. And the average force between the MC-LCP and ulna was one third less than that of the LC-DCP. Meanwhile, the interface contact area between the MC-LCP and humerus or radius was also about half of that of the LC-DCP, and the interface contact area between the MC-LCP and ulna was less than one third of that of the LC-DCP. These results indicate that the MC-LCP has lower interface contact area and lower average force than that of the LC-DCP. Thus, the MC-LCP system may be a good alternate to treat forearm diaphyseal fractures.

Neoadjuvant systemic therapy does not compromise local control after breast-conserving surgery: a single-center, propensity score matching study in China.

BACKGROUND: To investigate ipsilateral breast tumor recurrence (IBTR) in patients who have undergone breast-conserving surgery (BCS) after neoadjuvant systematic therapy (NST). METHOD: Three hundred and twenty-one patients undergoing BCS after NST and 2,534 patients undergoing initial BCS from June 2008 to June 2017 at Fudan University Shanghai Cancer Center were retrospectively enrolled, and statistical analyses, including propensity score matching, were applied to compare IBTR-free survival. The main factors related to IBTR in the NST group were estimated utilizing univariate and multivariate analyses. RESULTS: After propensity score matching, the 3-year IBTR-free survival rates were 93.7% (95% CI, 90.6-96.8%) in the NST group and 96.9% (95% CI, 94.9-98.9%) in the matched initial BCS group at a median follow-up period of 58 months. IBTR-free survival did not differ statistically between the two groups (P=0.154). According to multivariate analysis in the NST group, tumor-infiltrating lymphocytes (TILs), epidermal growth factor receptor 2 (HER2) status and pathologic ductal carcinoma in situ (DCIS) constituent were the factors related to IBTR after BCS. CONCLUSIONS: BCS after NST and initial BCS have equivalent IBTR-free survival. BCS after NST is a safe and effective therapy in terms of IBTR.

Repair of acutely injured spinal cord through constructing tissue-engineered neural complex in adult rats.

OBJECTIVE: To construct tissue-engineered neural complex in vitro and study its effect in repairing acutely injured spinal cord in adult rats. METHODS: Neural stem cells were harvested from the spinal cord of embryo rats and propagated in vitro. Then the neural stem cells were seeded into polyglycolic acid scaffolds and co-cultured with extract of embryonic spinal cord in vitro. Immunofluorescence histochemistry and scanning electron microscope were used to observe the microstructure of this complex. Animal model of spine semi-transection was made and tissue-engineered neural complex was implanted by surgical intervention. Six weeks after transplantation, functional evaluation and histochemistry were applied to evaluate the functional recovery and anatomic reconstruction. RESULTS: The tissue-engineered neural complex had a distinct structure, which contained neonatal neurons, oligodendrocytes and astrocytes. After tissue-engineered neural complex was implanted into the injured spinal cord, the cell components such as neurons, astrocytes and oligodendrocytes, could survive and keep on developing. The adult rats suffering from spinal cord injury got an obvious neurological recovery in motor skills. CONCLUSIONS: The tissue-engineered neural complex appears to have therapeutic effects on the functional recovery and anatomic reconstruction of the adult rats with spinal cord injury.

Frequent CpG island methylation: a risk factor in the progression of traditional serrated adenoma of the colorectum.

BACKGROUND: Traditional serrated adenoma (TSA) features a unique serrated configuration because it involves two cell types: tall and short columnar cells. The serrated neoplasia pathway is related to the carcinogenesis of colorectal cancer. CpG island methylator phenotype-high (CIMP-high) is a unique genetic alteration in this pathway. MATERIALS AND METHODS: This study investigated the prevalence and level of methylation and CIMP in 30 TSA cases. The tall and short cells in 28 TSAs were separated by microdissection. Methylation-specific PCR was performed to detect the methylation of MGMT, MLH1, P14, P16, MINT1, MINT2 and MINT31. RESULTS: Overall, 30 cases presented CIMP-high, and the prevalence of CIMP-high was 100% (30/30) in tall cells and 93% (28/30) in short cells. CONCLUSIONS: No significant difference was found between tall and short columnar cells. The relationship between methylation and clinicopathological characters remains to be established.

Primary total hip arthroplasty for acetabular fracture.

OBJECTIVE: To explore the operative indications and operative methods of primary total hip arthroplasty for acetabular fracture and to observe the clinical curative effect. METHODS: We retrospectively summarized and analyzed the traumatic conditions, fracture types, complications, operative time, operative techniques, and short term curative effect of 11 patients (10 males and 1 female, with a mean age of 42.4 years) with acetabular fracture who underwent primary total hip arthroplasty. RESULTS: The patients were followed up for 6-45 months (mean=28 months). Their average Harris score of postoperative hip joint was 78. CONCLUSION: Under strict mastery of indications, patients with acetabular fracture may undergo primary total hip arthroplasty, but stable acetabular components should be made.

Pulmonary microvascular dysfunction and pathological changes induced by blast injury in a rabbit model.

BACKGROUND: Vascular leakage has been proven to play a critical role in the incidence and development of explosive pulmonary barotrauma. Quantitatively investigated in the present study was the severity of vascular leakage in a gradient blast injury series, as well as ultrastructural evidence relating to pulmonary vascular leakage. METHODS: One hundred adult male New Zealand white rabbits were randomly divided into 5 groups according to distance from the detonator (10 cm, 15 cm, 20 cm, 30 cm, and sham control). Value of pulmonary vascular leakage was monitored by a radioactive 125I-albumin labeling method. Pathological changes caused by the blast wave were examined under light and electron microscopes. RESULTS: Transcapillary escape rate of 125I-albumin and residual radioactivity in both lungs increased significantly at the distances of 10 cm, 15 cm, and 20 cm, suggesting increased severity of vascular leakage in these groups. Ultrastructural observation showed swelling of pulmonary capillary endothelial cells and widened gap between endothelial cells in the 10-cm and 15-cm groups. CONCLUSION: Primary blast wave can result in pulmonary capillary blood leakage. Blast wave can cause swelling of pulmonary capillary endothelial cells and widened gap between endothelial cells, which may be responsible for pulmonary vascular leakage.