Visualization and quantification of anastomotic perfusion in colorectal surgery using near-infrared fluorescence.

BACKGROUND: Anastomotic leakage (AL) is one of the most troublesome complications in colorectal surgery. Recently, near-infrared fluorescence (NIRF) imaging has been used intraoperatively to detect sentinel lymph nodes and visualize the blood supply at the region of interest (ROI). The aim of this study was to evaluate the role of visualization and quantification of bowel perfusion around the anastomosis using NIRF system in predicting AL. METHODS: A prospective study was conducted on patients who had laparoscopic surgery for colorectal cancer at our institution. Perfusion of the anastomosis was evaluated with NIRF imaging after intravenous injection of indocyanine green (ICG). The time course of fluorescence intensity was recorded by an imaging analyzer We measured the time from ICG injection to the beginning of fluorescence (T0), maximum intensity (Imax), time to reach Imax (Tmax), time to reach Imax 50% ([Formula: see text]) and slope (S) after the anastomosis. RESULTS: Tumor locations were as follows; cecum: 2, ascending colon: 2, transverse colon: 7, descending colon: 1, sigmoid colon: 2, rectosigmoid colon: 3 and rectum: 6 (one case with synchronous cancer). All operations were performed laparoscopically. Four patients were diagnosed with or suspected to have AL (2 patients with grade B anastomotic leakage after low anterior resection, 1 patient with minor leakage in transverse colon resection and 1 patient needing re-anastomosis intraoperatively in transverse colon resection). T0 was significantly longer in the AL group than in patients without AL (64.3 ± 27.6 and 18.2 ± 6.6 s, p = 2.2 × 10-3). CONCLUSIONS: Perfusion of the anastomosis could be successfully visualized and quantified using NIRF imaging with ICG. T0 might be a useful parameter for prediction of AL.

Randomized clinical trial of defaecatory function after anterior resection for rectal cancer with high versus low ligation of the inferior mesenteric artery.

BACKGROUND: Defaecatory function is often poor after anterior resection. Denervation of the neorectum following high ligation of the inferior mesenteric artery (IMA) is a possible cause of impaired defaecatory function. The purpose of this randomized clinical trial was to clarify whether the level of ligation of the IMA in patients with rectal cancer affects defaecatory function. METHODS: Between 2008 and 2011, patients who underwent anterior resection for rectal cancer were randomized to receive either high or low ligation of the IMA. The primary endpoint was to demonstrate the superiority of low ligation in terms of defaecatory function. RESULTS: One hundred patients were enrolled in the study; 51 were randomized to high ligation of the IMA and 49 to low ligation. There were no differences between the groups in terms of clinical data, except tumour stage, which was more advanced in the high-ligation group (P = 0·046). Nor were there any differences in defaecatory function, self-assessment of defaecation, Faecal Incontinence Quality of Life scale or continence score between groups at 3 months and 1 year. The number of harvested lymph nodes was similar. The rate of symptomatic anastomotic leakage was 16 per cent in the high-ligation group and 10 per cent in the low-ligation group (P = 0·415). CONCLUSION: The level of ligation of the IMA in patients with rectal cancer did not affect defaecatory function or the incidence of postoperative complications. REGISTRATION NUMBER: NCT00701012 (http://www.clinicaltrials.gov).

Circulating tumour cells detected by a novel adenovirus-mediated system may be a potent therapeutic marker in gynaecological cancers.

BACKGROUND: Recently developed detection system for circulating tumour cells (CTCs) using a telomerase-specific replicative adenovirus generated nonspecific green fluorescent protein (GFP) signals because of the co-presence of white blood cells (WBCs) nonspecifically infected by viruses. Here, we established a unique detection system for CTCs that completely excludes nonspecific signals. METHODS: Blood obtained from the patients was subjected to haemolytic processes to eliminate red blood cells. The cell pellets were then infected with OBP-401, fixed, incubated with fluorescence-labelled anti-CD45 antibody to mark white blood WBCs, and examined on slides under a microscope. RESULTS: Preparatory experiments with cancer cells artificially added to healthy donor samples confirmed that CD45 labelling could distinguish GFP-positive cancer cells from WBCs. In 53 patients with gynaecological cancers, CTCs were detected in 21 patients (39.6%) when CD45-positive cells were excluded as WBCs among GFP-positive cells. No CTCs were detected in samples from healthy volunteers. There was no significant correlation between CTC counts and known clinicopathological factors. The CTCs rapidly vanished after surgery or chemotherapy in most patients whose treatments were effective. In contrast, the persistence of CTCs even after treatments was tightly associated with poor response to the treatments (P<0.005). CONCLUSION: The presence of CTCs in our system may potentially be a novel therapeutic marker in gynaecological cancers.

Creation of immortalised epithelial cells from ovarian endometrioma.

BACKGROUND: Epithelial cells of endometriotic tissues are difficult to propagate in vitro as experimental material is scarce owing to their limited life span. However, there is an increasing concern regarding their malignant transformation in ovaries. The present study sought to generate their stable culture system. METHODS AND RESULTS: Purified epithelial cells isolated from ovarian endometriomas using microscopic manipulation were successfully immortalised by combinatorial transfection of human cyclinD1, cdk4 and human telomerase reverse transcriptase (hTERT) genes, whereas the introduction of hTERT alone, or together with cdk4, was insufficient for immortalisation, leading to cellular senescence. We confirmed stable cytokeratin expression in the immortalised cells, proving their epithelial origin. These cells expressed progesterone receptor B and showed significant growth inhibition by various progestins. Oestrogen receptor (ER) expression was detected in these cells, albeit at low levels. Additional overexpression of ERα generated stable cells with oestrogen-dependent growth activation. Soft-agar colony formation assay and nude mice xenograft experiments demonstrated that these cells, even those with additional inactivation of p53, did not have transformed phenotypes. CONCLUSION: We for the first time generated immortalised epithelial cells from ovarian endometrioma that retained sex steroid responsiveness. These cells are invaluable tools not only for the consistent in vitro work but also for the study of molecular pathogenesis or carcinogenesis of endometriosis.

Foetal exposure to phthalate esters and anogenital distance in male newborns.

Phthalate esters, commonly used as plasticizers, show anti-androgenic activity and cause male reproductive malformation in experimental animals. However, the effects of prenatal exposure to phthalate esters in humans have not been extensively studied. The purpose of this study was to examine the relationship between prenatal exposure to phthalate esters and the anogenital distance (AGD) as a reproductive endpoint in human male newborns. Spot urine samples were collected from 111 Japanese pregnant women after obtaining their informed consent. Seven urinary phthalate ester metabolites were determined by high performance liquid chromatography-tandem mass spectrometry. Urinary isoflavones concentrations were measured as possible covariates because their oestrogenicities and high exposure levels among Japanese have the potential to affect male genital development. Birth outcomes and AGD, the distance from the centre of the anus to external genitalia, were measured for their male newborns. In a multiple regression model, the log-transformed mono-2-ethylhexyl phthalate concentration (specific gravity-corrected) was negatively significant, and maternal smoking status was positively significant, in explaining anogenital index (AGI) when potential covariates were controlled for. Urinary isoflavones did not significantly contribute to AGI in any models. Our results suggest that prenatal exposure to di(2-ethylhexyl) phthalate affects reproductive development in human males.

An optical spectrum of the afterglow of a gamma-ray burst at a redshift of z = 6.295.

The prompt gamma-ray emission from gamma-ray bursts (GRBs) should be detectable out to distances of z > 10 (ref. 1), and should therefore provide an excellent probe of the evolution of cosmic star formation, reionization of the intergalactic medium, and the metal enrichment history of the Universe. Hitherto, the highest measured redshift for a GRB has been z = 4.50 (ref. 5). Here we report the optical spectrum of the afterglow of GRB 050904 obtained 3.4 days after the burst; the spectrum shows a clear continuum at the long-wavelength end of the spectrum with a sharp cut-off at around 9,000 A due to Lyman alpha absorption at z approximately 6.3 (with a damping wing). A system of absorption lines of heavy elements at z = 6.295 +/- 0.002 was also detected, yielding the precise measurement of the redshift. The Si ii fine-structure lines suggest a dense, metal-enriched environment around the progenitor of the GRB.

Expression of HER-2 affects patient survival and paclitaxel sensitivity in endometrial cancer.

BACKGROUND: Disabled phosphatidylinositol 3-kinase (PI3K)/AKT and mitogen-activated protein kinase/extracellular signal-regulated kinase signalling is involved in endometrial carcinogenesis, and there is evidence that expression of epidermal growth factor receptor (EGFR) family members has a role in such intracellular signalling pathways. This study analysed the prognostic impact of EGFR family expression in endometrial cancer in relation to PI3K-AKT and MAPK-ERK signalling, as well as drug sensitivity. METHODS AND RESULTS: Immunohistochemical analysis using 63 surgical specimens of endometrioid-type endometrial cancers revealed that EGFR, human epidermal growth factor receptor (HER)-2 and HER-4 were expressed in 25 (39.7%) of 63, 26 (41.3%) of 63 and 31 (49.2%) of 63 tumours, respectively. Gene amplification of HER-2 was observed in 2 of 26 patients with high HER-2 expression. Kaplan-Meier analysis revealed that high HER-2 expression was a factor that negatively influenced the progression-free and overall survival rate (P<0.05), and multivariate analysis showed high HER-2 expression to be an independent prognostic factor. Subsequently, we performed in vitro knockdown analysis to investigate the linkage between HER-2 expression and PI3K-AKT pathways. Short interfering RNA (siRNA)-based knockdown of HER-2 in endometrial cancer cells led to a significant reduction in phosphorylated AKT (p-AKT) expression, indicating the existence of a HER-2/PI3K-AKT axis. As the PI3K-AKT pathway is known to have crucial roles in anticancer drug sensitivity, we examined the involvement of HER-2 in sensitivity to paclitaxel. Short interfering RNA-based knockdown of HER-2 conferred increased sensitivity to paclitaxel in endometrial cancer cells, attenuating the induction of p-AKT on paclitaxel stimulation, which was cancelled by inactivating AKT by the introduction of a dominant-negative form. CONCLUSION: HER-2 is a significant prognostic factor of endometrioid-type endometrial cancer, as well as a key molecule that affects paclitaxel sensitivity by HER-2 interaction with the PI3K-AKT pathway.

The Culdotomy FourS Two U procedure for transvaginal access to the peritoneal cavity.

A reliable method of transvaginal access is needed for natural orifice transluminal endoscopic surgery. We introduce a new culdotomy procedure, using a technique for the creation of space in the cul-de-sac, transvaginal ultrasound, and a newly developed umbrella Hakko needle. An artificially developed, saline-containing space in the cul-de-sac was punctured by an umbrella Hakko needle from the vagina under the guidance of ultrasound. The vaginal walls on both sides of the needle were incised with an electric scalpel. In five cases with benign gynecological tumors, culdotomy was successfully performed. Operating time was less than 10 minutes and blood loss was less than 10 mL. There were no culdotomy-associated complications. This procedure, named Culdotomy FourS Two U, is a simple, safe, and reliable method for entry into the cul-de-sac in transvaginal gynecological surgeries and may have future applications in transluminal endoscopic surgery through the vagina.

Ultrasound-guided culdotomy for vaginal ovarian cystectomy using a renal balloon dilator catheter.

OBJECTIVES: To evaluate the feasibility and utility of performing ultrasound-guided culdotomy using a renal balloon dilator catheter for transvaginal ovarian cystectomies. METHODS: Culdotomy using transvaginal sonography and a Nephromax balloon dilator catheter was performed in 16 patients for the vaginal removal of benign ovarian cysts located in the cul-de-sac. Each ovarian cyst was punctured under transvaginal ultrasound guidance and the punctured site on the vaginal wall was enlarged with a dilator. The cyst was then enucleated through this vaginal wound. Preoperative characteristics of the patients, outcome, operating time, blood loss and complications of each culdotomy, and the histology of the cysts, were recorded and examined. RESULTS: We used this method on 14 patients with unilateral ovarian cysts and two with bilateral cysts. Culdotomy was performed successfully in 15 cases (94%). The mean +/- SD operating time for culdotomy was 22 +/- 11 min, and blood loss during the procedure was less than 10 mL in all cases. There were no complications including rectal injury or febrile morbidity. CONCLUSIONS: Culdotomy assisted by ultrasound imaging and a dilator is a safe, reliable and effective method for removal of benign ovarian cysts via a vaginal approach.

Creation of tumorigenic human endometrial epithelial cells with intact chromosomes by introducing defined genetic elements.

Several genetic mutations have been identified in human endometrial cancers, but the specific combinations of mutations required to form endometrial cancer cells remain unknown. In the present study, we established an in vitro model of endometrial carcinogenesis, in which defined genetic elements were introduced into endometrial epithelial cells to create transformed endometrial cells at different stages. Introduction of the human papillomavirus type 16 E6/E7 gene and the human telomerase reverse transcriptase (hTERT) gene into human primary endometrial epithelial cells was sufficient to generate immortalized cells. Introduction of hTERT in early passages stabilized telomeres and created immortalized cells with normal karyotype, whereas introduction of hTERT in later passages generated immortalized cells but with widespread chromosome abnormalities. However, neither of those two immortalized cell lines exhibited tumorigenic phenotypes. Tumorigenic endometrial epithelial cells with invasive capacity were created by introducing a mutant K-ras allele into immortalized cells, keeping their chromosomes intact. Inhibiting the PTEN gene and activating Akt pathways did not create tumorigenic phenotypes, although the latter conferred anchorage-independent growth capacity. These findings suggest that neoplastic transformation of human endometrial cells can occur in the absence of widespread chromosomal abnormality, and that the combination of Rb inactivation, telomerase activation and altered K-ras signaling is sufficient for in vitro neoplastic transformation. The present experimental model can help clarify the genetic requirements for endometrial carcinogenesis, and it is useful for testing and developing specific inhibitors of specific oncogenic pathways.

Neurophysin biosynthesis in vitro in oat cell carcinoma of the lung with ectopic vasopressin production.

The incorporation of labeled compounds into neurophysins of a transplantable human oat cell carcinoma of the lung with ectopic vasopressin production was studied in vitro. Neurophysins in cell extracts and in incubation media were isolated by immunoprecipitation and analyzed by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis. When cells were incubated with L-[35S]cysteine for 12 h, SDS-polyacrylamide gel electrophoresis of the immunoprecipitates from cell extract and medium resolved two forms of neurophysins with apparent molecular mass of 10,000 (10K) and 20,000 (20K). Both forms of [35S]-neurophysins were completely displaced from the immunoprecipitates by excess human neurophysin. Incubation of cells with L-[35S]cysteine and D-[3H]-glucosamine hydrochloride revealed that glucosamine was incorporated into the 20K neurophysin region, but not into 10K species. To observe the kinetics of labeling of the two forms of neurophysins, cells were incubated with L[35S]cysteine for varying periods of time. After short labeling periods, most of the radioactivity resided in 20K species, which plateaued after 1 h, whereas 10K neurophysin progressively increased in its height. When cells were chased with unlabeled cysteine after the exposure to a short pulse of labeling, 20K neurophysin peak gradually decreased with an apparent initial half-life of 1 h. In contrast, the label in 10K neurophysin steadily increased, which exceeded the former by 3 h of chase. Analysis of 20K neurophysin in cell extract by isoelectric focusing on polyacrylamide gel demonstrated that it was principally composed of a protein with an apparent isoelectric point (pI) of 5.7. These results suggest that neurophysin is synthesized in ectopic vasopressin-producing tumors by post-translational processing from a glycosylated proneurophysin with an apparent molecular mass of 20,000 daltons and a pI of 5.7.

Analysis of outcome of Stage I-III endometrial cancer treated with systematic operation omitting paraaortic lymphadenectomy.

PURPOSE: The aim of this study was to assess the outcomes of endometrial cancer patients treated with systematic surgery omitting paraarotic lymphadenectomy. PATIENTS AND METHODS: We retrospectively analyzed a consecutive series of 84 endometrioid-type endometrial cancer patients at FIGO Stage I, II or III without grossly metastatic paraaortic lymphadenodes, who underwent surgery at our institute. RESULTS: Sixty-five patients (77%) underwent primary surgery with pelvic lymphadenectomy while the remaining 19 patients underwent surgery without lymphadenectomy due to severe medical complications or age greater than 70 years. The patients with high risk for recurrence were treated mainly by adjuvant irradiation therapy of the whole pelvis. The median follow-up period was 44 months. The 5-year overall survival (OS) rate was 92%, 92% and 65% for FIGO Stage I, II and III, respectively. Recurrence was detected in eight of the 82 optimally operated patients (9.8%). Out of the eight recurrent patients, five patients had a recurrent tumor at extra-pelvic sites (chest or abdomen), two patients had a recurrent tumor only in a paraaortic lymph node, and one patient had a recurrent tumor only in the vagina. Thus, the recurrence rate was relatively low, with 2.4% relapse at the paraarotic lymph nodes, and 5-year OS rate appeared to be favorable. However, all the six recurrent patients who underwent adjuvant radiation therapy had distant recurrence. CONCLUSIONS: These findings indicate that omission of paraarotic lymphadenectomy may be acceptable for endometrial cancer patients without gross metastasis at this site. However, the high rate of distant recurrence after whole pelvic irradiation strongly indicates an urgent need to develop potent systemic adjuvant therapy, potentially by chemotherapy or chemoradiation therapy.

High incidence of hepatocellular carcinomas induced by a choline deficient L-amino acid defined diet in rats.

The carcinogenicities of a choline deficient L-amino acid defined (CDAA) diet and a semipurified choline deficient diet were comparatively examined. A total of 60 male Fischer 344 rats, 6 weeks old, were divided into 5 experimental groups each consisting of 12 rats. Group 1 received the CDAA diet chronically to the end of the 52-week experiment while Group 2 was given the same diet for the first 24 weeks and then a basal diet for the following 28 weeks. Groups 3, 4, and 5 received a choline supplemented L-amino acid defined diet, the semipurified choline deficient diet, and a semipurified choline supplemented diet, respectively, throughout the experimental period. All surviving rats were subjected to complete macroscopic examination at Week 52. Histopathologically diagnosed hepatocellular carcinomas were induced in Group 1 at an incidence of 100%; multiple metastatic nodules were seen in the lungs of one of the animals. Hepatocellular carcinomas were also induced in Group 4 rats at a significantly lower incidence of 20%. No hepatocellular carcinomas were observed in rats in Groups 2, 3, and 4. The results indicate that the CDAA diet exerts more potent carcinogenicity for the livers of rats than does the semipurified choline deficient diet. However, limited exposure for 24 weeks may have not been sufficient for hepatocellular carcinoma induction by the CDAA diet at Week 52 although a high incidence of hyperplastic nodules and slight cirrhosis were evidence of persistent lesions.

Inappropriate secretion of antidiuretic hormone in nude mice bearing a human bronchogenic oat cell carcinoma.

A 58-year-old man with bronchogenic oat cell carcinoma developed a typical syndrome of inappropriate secretion of antidiuretic hormone. The tumor tissue obtained at autopsy had been serially transplanted in nude mice for more than four years with 20 passages. The levels of vasopressin were remarkably increased in the plasma of nude mice bearing this tumor [24.4 +/- 18.3 (S.D.) pg/ml, n = 3] as well as in the tumor tissues ]134.3 +/- 72.2 ng/g, n = 3]. Furthermore, human nicotine-stimulated neurophysin was detected in both plasma and tumor tissues (7.4 +/- 3.7 ng/ml, n = 3, and 2.28 +/- 0.90 micrograms/g, n = 3, respectively). On ad libitum intake of water, nude mice bearing this tumor excreted significantly less urine with higher sodium concentration than did controls, but serum sodium concentrations did not differ from those of controls. When tumor-bearing mice were hydrated with 2 ml of water twice a day i.p., their diuretic response was found to be suppressed in parallel with the tumor size. However, these mice did not become hyponatremic because they drank less water. When a larger amount of water was loaded which could not be compensated by restriction of water drinking, serum sodium concentrations were markedly decreased. On the basis of these results, the lung cancer, when transplanted into nude mice, produced and secreted its own antidiuretic hormone, which induced inappropriate secretion of antidiuretic hormone in the mice. These mice may provide a useful experimental model for the study of excessive secretion of antidiuretic hormone and associated pathophysiological disorders.

Improved genomic/nuclear DNA extraction for 8-hydroxydeoxyguanosine analysis of small amounts of rat liver tissue.

Using two different commercially available extraction kits, genomic/nuclear DNA could be recovered from rat liver samples as small as 10 mg. Background 8-hydroxydeoxyguanosine levels in such DNA were low and stable at 0.26-0.30 +/- 0.01-0.03/10(5) guanine residues. The minimum tissue wet weight required for the accurate 8-hydroxydeoxyguanosine analysis was 25 mg. The present results indicate that routine and reliable assessment of the involvement of oxidative DNA damage in the development of various diseases, including cancer, is feasible using a variety of tissue sources.

Selective 8-hydroxyguanine formation in pancreatic DNA due to a single intravenous administration of 4-hydroxyaminoquinoline 1-oxide in rats.

8-Hydroxyguanine (8-OHG) formation, a possible initiating event, was determined in pancreatic and liver DNA and compared with the genesis of acinar cell and hepatocyte necrosis in male Wistar rats given a single intravenous administration of 4-hydroxyaminoquinoline 1-oxide (4-HAQO). At the non-necrotic but tumorigenic dose of 7.0 mg/kg body weight, 8-OHG was selectively generated in pancreatic DNA, in the absence of acinar cell necrosis, at the 6 and 24 h time points and repaired by the 48 h time point. When rats were exposed to 4-HAQO at a necrotic dose of 14.0 mg/kg body weight, 8-OHG was also selectively formed in pancreatic DNA with the same time-dependence of generation and repair, while acinar cell necrosis became evident at the 24 h time point and progressed thereafter. Whereas no hepatocyte necrosis was detected in any rats, 8-OHG values for liver DNA merely expressed slight increases only at the 24 and 48 h time points in rats given 14.0 mg/kg body weight of 4-HAQO. The present data suggest that formation of oxidative DNA damage, assayed by 8-OHG, in pancreatic DNA is independent from toxicity and may be involved, along with quinoline adducts, in mutational events underlying 4-HAQO-induced rat acinar cell carcinogenesis.

A genomic element within the third intron of the human oxytocin receptor gene may be involved in transcriptional suppression.

The human oxytocin receptor (OTR) gene comprises a large (> 10 kb) third intron between the regions encoding the transmembrane domains six and seven. It has been shown for other genes that transcriptional control elements may reside within such introns, and that these may correlate with changes in the methylation status of the DNA. Methylation mapping indeed indicated that within this third intron there was a region which appeared to be hypermethylated in non-expressing tissues, but relatively hypomethylated in the myometrium of the cycle and at term, when the OTR gene is upregulated. We then employed in vitro nuclear protein-DNA binding assays to evaluate the importance of this region in the control of the human OTR gene. As source of nuclear proteins we have compared a non-expressing tissue, human peripheral blood leucocytes, with human myometrium from the cycle (low expression) and from term pregnancy (high expression). It could be shown that a specific motif of ca. 10-15 nucleotides close to the middle of the third intron specifically binds nuclear proteins correlating with the down-regulated state of the gene. The accumulated data suggest that this intronic element is specifically binding nuclear protein(s) associated with a suppression of OTR gene activity.

Differential protein-DNA binding analysis identifies a novel enhancer element, US-1, involved in the upregulation of the oxytocin receptor gene in human myometrium at term.

In order to investigate the regulatory mechanisms involved in the transcription of the human oxytocin receptor (OTR) gene in the human myometrium at term of pregnancy, we subjected the 5' flanking region of the gene to a differential EMSA (electrophoretic mobility shift assay) procedure. Comparing nuclear proteins from term myometrium, in which OTR gene transcription is massively up-regulated, with those from the non-pregnant myometrium, indicated a prominent DNA-protein complex using the former extract. The sequence of the protein binding site was determined within 20 bp (TCTGCCTTCATCCAGCC) and designated as uterine stimulator motif-1 (US-1). The concatemerized US-1 sequence exhibited enhancer activity using a minimal thymidine kinase promoter (tk-81) in transfected SKN cells. We partially purified US-1 binding protein from SKN cells using a resin bead affinity procedure. Binding activity could be concentrated, although the protein eluate still comprised more than 20 component polypeptides. The molecular weight of the principal protein-DNA complex was determined following UV crosslinking to be 70 kDa. In circumstances where a cell-line mimicking the pregnant uterus at term is not available, the differential EMSA strategy, comparing OTR DNA protein binding in up- and down-regulated tissues, provides a powerful tool to investigate OTR regulation in the uterus. However, the precise characterization and identity of the specific DNA-binding protein(s) and consequent experimental verification of regulatory mechanisms still require elucidation.

Protection against lipid peroxidation induced during preservation of lungs for transplantation.

The questions of whether oxygen-derived free radicals are induced during preservation of lungs and, if so, how such radicals might relate to reperfusion injury were investigated by means of an isolated canine lung model. Lungs were obtained from 16 mongrel dogs and divided into groups 1 (n = 6), 2 (n = 5), and 3 (n = 5). The lungs of groups 1, 2, and 3 were flushed through the pulmonary artery with Euro-Collins solution alone, the solution with superoxide dismutase (120,000 U/L), and the solution with allopurinol (1 mmol/L), respectively, at 4 degrees C and then stored for 4 hours in the respective solutions at 4 degrees C with clamped bronchi. They were then reperfused for 2 hours by means of an isolated lung model. Lung lipid peroxidation was sequentially determined. The lung functional status was assessed by systolic pulmonary arterial pressure and end-inspiratory airway pressure. The lung edema was assessed by lung wet/dry weight ratio. Lipid peroxidation was induced after 1 hour of preservation and the first 30 minutes of the reperfusion in group 1 and only 2 hours of the reperfusion in group 2, whereas no induction was observed in group 3. Values for systolic pulmonary arterial pressure and end-inspiratory pressure in group 1 were significantly higher than those in group 3 (p < 0.05). The lung wet/dry weight ratio in group 1 was significantly higher than that in groups 2 and 3 (p < 0.05). The present results indicate that the administration of free radical scavengers in the preservation may effectively improve conditions for lung transplantation.