Current status of integrating oncology and palliative care in Japan: a nationwide survey.

BACKGROUND: Palliative care (PC) is increasingly recognized as essential for oncology care, and several academic societies strongly recommend integrating oncology and palliative care (IOP) in daily practice. Similarly, the Japanese government encouraged the implementation of IOP through the Cancer Control Act of 2007; however, its detailed progress remains unclear. Therefore, this cross-sectional nationwide survey was conducted to investigate the current status and hospital executive physicians' perception of IOP. METHODS: The questionnaire was developed based on IOP indicators with international consensus. It was distributed to executive physicians at all government-designated cancer hospitals (DCHs, n = 399) and matched non-DCHs (n = 478) in November 2017 and the results were compared. RESULTS: In total, 269 (67.4%) DCHs and 259 (54.2%) non-DCHs responded. The number of PC resources in DCHs was significantly higher than those in non-DCHs (e.g., full-time PC physicians and nurses, 52.8% vs. 14.0%, p < 0.001; availability of outpatient PC service ≥3 days per week, 47.6% vs. 20.7%, p < 0.001). Routine symptom screening was more frequently performed in DCHs than in non-DCHs (65.1% vs. 34.7%, p < 0.001). Automatic trigger for PC referral availability was limited (e.g., referral using time trigger, 14.9% vs. 15.3%, p = 0.700). Education and research opportunities were seriously limited in both types of hospitals. Most executive physicians regarded IOP as beneficial for their patients (95.9% vs. 94.7%, p = 0.163) and were willing to facilitate an early referral to PC services (54.7% vs. 60.0%, p < 0.569); however, the majority faced challenges to increase the number of full-time PC staff, and < 30% were planning to increase the staff members. CONCLUSIONS: This survey highlighted a considerable number of IOP indicators met, particularly in DCHs probably due to the government policy. Further efforts are needed to address the serious research/educational gaps.

Interleukin-25 is involved in cutaneous T-cell lymphoma progression by establishing a T helper 2-dominant microenvironment.

BACKGROUND: Interleukin (IL)-25 is a member of the IL-17 family, which can promote and augment T-helper (Th) type 2 responses. The expression of IL-25 and its cognate receptor, IL-25 receptor (IL-25R), is upregulated and correlated with disease activity in Th2-associated diseases. OBJECTIVES: To examine the expression and function of IL-25 in cutaneous T-cell lymphoma (CTCL). METHODS: Expression and location of IL-25 in lesional skin was investigated with immunohistochemistry. The effect of various cytokines on IL-25 production from normal human epidermal keratinocytes was assessed by quantitative reverse-transcription real-time polymerase chain reaction. Serum IL-25 levels were measured by enzyme-linked immunosorbent assay. The direct effect of IL-25 on tumour cells was also examined using CTCL cell lines and peripheral blood mononuclear cells in patients with Sézary syndrome. RESULTS: IL-25 expression was increased in epidermal keratinocytes in lesional skin of CTCL. Th2 cytokines, IL-4 and IL-13, and periostin induced IL-25 expression by normal human epidermal keratinocytes. Serum IL-25 levels were increased in patients with advanced CTCL and correlated with serum lactate dehydrogenase levels. MyLa cells expressed IL-25R and its expression was augmented by stimulation with IL-25. IL-25 enhanced IL-13 production from MyLa cells via phosphorylation of signal transducer and activator of transcription 6. Peripheral blood mononuclear cells from one patient with Sézary syndrome expressed IL-25R and showed increase of IL-13 production by IL-25. CONCLUSIONS: Th2 cytokines highly expressed in CTCL lesional skin induce IL-25 production by epidermal keratinocytes, which may, in turn, lead to formation of a Th2-dominant microenvironment through the direct induction of IL-13 by tumour cells.

Fucosylated TGF-ß receptors transduces a signal for epithelial-mesenchymal transition in colorectal cancer cells.

BACKGROUND: Transforming growth factor-ß (TGF-ß) is a major inducer of epithelial-mesenchymal transition (EMT) in different cell types. TGF-ß-mediated EMT is thought to contribute to tumour cell spread and metastasis. Sialyl Lewis antigens synthesised by fucosyltransferase (FUT) 3 and FUT6 are highly expressed in patients with metastatic colorectal cancer (CRC) and are utilised as tumour markers for cancer detection and evaluation of treatment efficacy. However, the role of FUT3 and FUT6 in augmenting the malignant potential of CRC induced by TGF-ß is unclear. METHODS: Colorectal cancer cell lines were transfected with siRNAs for FUT3/6 and were examined by cell proliferation, invasion and migration assays. The expression and phosphorylation status of TGF-ß downstream molecules were analysed by western blot. Fucosylation of TGF-ß receptor (TßR) was examined by lectin blot analysis. RESULTS: Inhibition of FUT3/6 expression by siRNAs suppressed the fucosylation of type I TßR and phosphorylation of the downstream molecules, thereby inhibiting the invasion and migration of CRC cells by EMT. CONCLUSION: Fucosyltransferase 3/6 has an essential role in cancer cell adhesion to endothelial cells by upregulation of sialyl Lewis antigens and also by enhancement of cancer cell migration through TGF-ß-mediated EMT.

The endoscopic diagnosis of nonerosive reflux disease using flexible spectral imaging color enhancement image: a feasibility trial.

Nonerosive reflux disease (NERD) is classified into grade M (minimal change, endoscopically; erythema without sharp demarcation, whitish turbidity, and/or invisibility of vessels due to these findings) and grade N (normal) in the modified Los Angeles classification system in Japan. However, the classification of grades M and N NERD is not included in the original Los Angeles system because interobserver agreement for the conventional endoscopic diagnosis of grades M or N NERD is poor. Flexible spectral imaging color enhancement (FICE) is a virtual chromoendoscopy technique that enhances mucosal and vascular visibility. The aim of this study is to evaluate whether the endoscopic diagnosis of grades M or N NERD using FICE images is feasible. Between April 2006 and May 2008, 26 NERD patients and 31 controls were enrolled in the present study. First, an experienced endoscopist assessed the color pattern of minimal change in FICE images using conventional endoscopic images and FICE images side-by-side and comparing the proportion of minimal change between the two groups. Second, three blinded endoscopists assessed the presence or absence of minimal change in both groups using conventional endoscopic images and FICE images separately. Intraobserver variability was compared using McNemar's test, and interobserver agreement was described using the kappa value. Minimal changes, such as erythema and whitish turbidity, which were detected using conventional endoscopic images, showed up as navy blue and pink-white, respectively, in color using FICE images in the present FICE mode. The NERD group had a higher proportion of minimal change, compared with the control group (77% and 48%, respectively) (P= 0.033). In all three readers, the detection rates of minimal change using FICE images were greater than those using conventional endoscopic images (P= 0.025, <0.0001, and 0.034 for readers A, B, and C, respectively). The kappa values for all pairs of three readers using FICE images were between 0.683 and 0.812, while those using conventional endoscopic images were between 0.364 and 0.624. Thus, the endoscopic diagnosis of grades M or N NERD using FICE images is feasible and may improve interobserver agreement.

Hepatic falciform ligament artery in patients with chronic liver diseases: detection on computed tomography hepatic arteriography.

BACKGROUND: The detection rate of hepatic falciform ligament artery (FLA) has been reported as ranging from 2-25%. The rate of FLA on laparotomy, however, is reported to be higher, at 68%. PURPOSE: To compare the detection rate of FLA on computed tomography hepatic arteriography (CTHA) with that on angiography and dynamic CT, and to clarify the clinical significance of FLA in patients with chronic liver disease. MATERIAL AND METHODS: 126 consecutive patients underwent CTHA angiography and dynamic CT to evaluate suspected liver tumors. Liver function was classified as follows: normal, n=5; Child-Pugh class A, n=94; B, n=21; and C, n=6. All CT images were obtained using multidetector (MDCT) scanners (Aquilion; Toshiba, Tokyo, Japan). For CTHA, CT images were obtained during contrast material injection through the left hepatic, proper, or common hepatic artery. On CT, FLAs were retrospectively identified within the hepatic falciform ligament and the hepatic round ligament by the paging method on a workstation (TWS-5000; Toshiba, Tokyo, Japan). The detection rates were compared among the three modalities (hepatic arterial phase of dynamic CT, CTHA, and angiography). The calibers of FLA were also correlated with the hepatic function of the patients. RESULTS: The detection rates of FLA by angiography, dynamic CT, and CTHA were 37% (47/126), 10% (13/126), and 77% (97/126), respectively. The calibers of FLA increased as the hepatic function deteriorated (P=0.001). CONCLUSION: The detection rates of FLA with CTHA are far higher than those with angiography and dynamic CT. Careful interpretation with recognition of FLA on CTHA images is important, as inadvertent embolization or chemotherapeutic infusion of the FLA may result in supraumbilical skin rash.

Microcoil embolization through a downsized coaxial catheter system: an experimental study.

BACKGROUND: Most of the recently developed microcatheters for abdominal angiography still have large diameters at their trailing ends, and thus cannot be used for microcoil embolization in combination with a 3-French (F) system. PURPOSE: To evaluate the in vitro passage of microcoils through a newly developed 2-F microcatheter (Meister Cath Superselective Plus, MC6) that is compatible with a downsized coaxial catheter system (3-F system) in an experimental study. MATERIAL AND METHODS: We evaluated the passage of microcoils through MC6 within a blood vessel model using the saline flush technique. Six types of microcoils and 17 size variations (maximal curled diameter 2-10 mm, total length 20-140 mm) were used. We evaluated the passage and post-deployment shape of the microcoils as well as the volume of saline required to flush them. RESULTS: In the experimental study, all microcoils passed through the MC6 and deployed in a satisfactory manner without catheter occlusion. The mean volumes of saline required to flush the TORNADO (n=1), Reverse TORNADO (n=6), HILAL (n=1), Micronester (n=3), VortX (n=4), and C-Stopper Coil (n=2) were 0.7 ml, 0.58+/-0.20 ml, 0.5 ml, 0.57+/-0.058 ml, 3.5+/-1.5 ml, and 0.70+/-0.14 ml, respectively. There was a statistically significant difference in the mean volume of saline required between the VortX and Reverse TORNADO (P=0.029), and between the VortX and C-Stopper Coil (P=0.031). The VortX required the greatest volume of saline. CONCLUSION: Microcoil embolization through a 3-F system appears to be feasible for the coils examined in this study.

Ganglioside complexes containing GQ1b as targets in Miller Fisher and Guillain-Barre syndromes.

BACKGROUND: Serum antibodies to GQ1b are associated with Miller Fisher syndrome (MFS) and Guillain-Barré syndrome (GBS) with ophthalmoplegia. Antibodies to ganglioside complexes (GSCs) have not yet been examined in a large population of patients with MFS or GBS. This study aimed to determine the clinical significance of antibodies to GSCs in MFS and GBS. METHODS: The study investigated serum anti-GSC antibodies and the clinical features in 64 MFS patients, 53 GBS patients with ophthalmoplegia (GBS-OP(+)) and 53 GBS patients without ophthalmoplegia (GBS-OP(-)). RESULTS: Thirty patients with MFS (47%), 25 with GBS-OP(+) (47%) and none with GBS-OP(-) had antibodies to GSCs containing GQ1b or GT1a. Patients with MFS and GBS-OP(+) were subdivided according to the antibody reactivities; patients with antibodies specific to GQ1b and/or GT1a (without anti-GSCs antibodies) were placed in Group 1, those with antibodies against GSCs with a total of two sialic acids in the terminal residues, such as GQ1b/GM1, were placed in Group 2, and those with antibodies against GSCs with a total of three sialic acids in the terminal residue, such as GQ1b/GD1a, were placed in Group 3. In MFS, sensory disturbances were infrequent in Group 2 compared with the other groups (p<0.0001). Antibodies specific to GQ1b were observed more often in MFS than in GBS-OP(+) (p = 0.0002). CONCLUSIONS: IgG antibodies to GSCs containing GQ1b or GT1a were closely associated with the development of ophthalmoplegia in GBS, as well as MFS. Both GQ1b and clustered epitopes of GSCs containing GQ1b or GT1a may be prime target antigens for MFS and GBS-OP(+).

Recurrent juvenile granulosa cell tumor of the ovary managed by palliative radiotherapy.

Prognosis in the few patients with advanced-stage juvenile granulosa cell tumor (JGCT) of the ovary has traditionally been unfavorable. We report a recurrent JGCT patient managed by palliative radiotherapy. A 37-year-old woman with recurrent JGCT received a combination of paclitaxel-carboplatin chemotherapy and then single-agent docetaxel, but her disease progressed with multiple abdominal masses and ascites. We chose palliative radiation therapy to relieve her complaints. Whole-abdominal external beam radiotherapy with pelvic boost was delivered. She tolerated the treatment well. After the completion of radiotherapy, ultrasonography showed shrinkage of the tumor, and the ascites disappeared. We should consider using radiation therapy in a palliative setting for such patients with recurrent JGCT suffering from abdominal complaints.

Neoadjuvant chemotherapy followed by extended-field concurrent chemoradiotherapy in squamous cell carcinoma of the cervix with positive paraaortic lymph nodes: two cases.

PURPOSE: To report the feasibility of neoadjuvant chemotherapy (NAC) followed by extended-field concurrent chemoradiotherapy (EF-CCRT) for squamous cell carcinoma of the cervix (CC) with paraaortic lymph node (PAN) metastasis. METHODS: Two patients were diagnosed with CC with positive PAN, and received two courses of cisplatin (120 mg/m2) in a neoadjuvant setting. They then received extended-field, external-beam radiotherapy (50.4 Gy) followed by intracavitary brachytherapy concurrently with cisplatin (20 mg/m2 x 5 days) at 21-day intervals. RESULTS: EF-CCRT was interrupted in one patient for five days because of grade 4 neutropenia. No severe late toxicities were observed. The two patients are alive with no evidence of recurrence at present. CONCLUSIONS: NAC followed by EF-CCRT is feasible and may improve the survival outcome of patients with CC with positive PAN.

Heparanase expression in endometrial cancer: analysis of immunohistochemistry.

The human enzyme heparanase has been shown to function in tumour progression, metastatic spread and tumour angiogenesis. The aim of the present study was to assess heparanase expression assessed by immunohistochemical staining (IHC) in endometrial cancer in correlation with clinicopathological factors. A total of 52 endometrial cancers were obtained from previously untreated patients (median age, 56 years, range, 35-80 years). The expression of heparanase was evaluated by using IHC with anti-heparanase polyclonal antibody. This antibody was raised by immunising a rabbit with a peptide containing the amino acid residues from 238 to 250 of the heparanase. The IHC data were used to determine the relationship between heparanase expression, and clinicopathological parameters. IHC showed that the heparanase was expressed in 23 of 52 (44.2%) endometrial cancers. Heparanase was abundantly and equally expressed in both the cytoplasm and the cell membrane of the cells in endometrial cancer. Strong heparanase-positive staining was also seen at the invasive front of the tumour into myometrium. The expression was significantly related to lymph-vascular space involvement (p = 0.0028), depth of myometrial invasion (p = 0.0026), and histological tumour grade (p = 0.0135). In six tumours with positive lymph nodes, the heparanase expression was observed as being higher compared with tumours with negative lymph nodes, which was not significant (p = 0.2349). In terms of peritoneal cytology, ovarian metastasis, and cervical invasion, we observed no significant difference in the heparanase expression assessed by IHC. These results suggest that the expression of heparanase may promote tumour invasion into myometrium and lymph vascular space in endometrial cancer.

Anti-ganglioside complex antibodies associated with severe disability in GBS.

Ganglioside complexes (GSCs) are known as target antigens in Guillain-Barré syndrome (GBS). To elucidate the clinical importance of the anti-GSC antibodies in GBS, we investigated serum antibodies to GSCs containing two of the gangliosides, GM1, GD1a, GD1b and GT1b, and analyzed clinical features of anti-GSC-positive GBS patients. Thirty-nine (17%) of 234 GBS patients had IgG anti-GSC antibodies. Anti-GSC-positive GBS had antecedent gastrointestinal infection and lower cranial nerve deficits more frequently than control GBS. The presence of antibody specificity to GD1a/GD1b and/or GD1b/GT1b was significantly associated with severe disability and a requirement for mechanical ventilation.

Anti-ganglioside complex antibodies in Miller Fisher syndrome.

BACKGROUND: Some ganglioside complexes (GSCs) are target antigens for serum antibodies in patients with Guillain-Barré syndrome (GBS). Anti-GSC antibodies may be associated with particular clinical features of GBS. OBJECTIVE: To investigate antibodies to GSCs in the sera of patients with Miller Fisher syndrome (MFS) characterised by elevation of the IgG anti-GQ1b antibody. RESULTS: In all, 7 of 12 (58%) consecutive patients with MFS were found to have IgG antibodies to GSCs containing GQ1b, of whom 5 had IgG antibodies to GQ1b-GM1 complex (GQ1b/GM1) and 2 had antibodies to GQ1b/GD1a; 4 of 5 patients without sensory symptoms had anti-GQ1b/GM1 antibodies. CONCLUSIONS: At least three different specificities in MFS-associated antibodies, GQ1b-specific, anti-GQ1b/GM1-positive and anti-GQ1b/GD1a-positive, were observed. In patients with MFS not only GQ1b itself but also clustered epitopes of GSCs, including GQ1b, may be considered to be prime target antigens for serum antibodies. A tendency to escape sensory disturbances is shown by anti-GQ1b/GM1-positive MFS.

Genome structure of the Lactobacillus temperate phage phi g1e: the whole genome sequence and the putative promoter/repressor system.

The complete genome sequence of a Lactobacillus temperate phage phi g1e was established. The double-stranded DNA is composed of 42,259 bp, and encodes for sixty-two possible open reading frames (ORF) as well as several potential regulatory sequences. Based on comparative analysis with other related proteins of the Lactobacillus and Lactococcus phages as well as the Escherichia coli phages (such as lambda), functions were putatively assigned to several phi g1e ORFs: cng and cpg (encoding for repressors), hel (helicase), ntp (NTPase), and several ORFs (e.g., minor capsid proteins). An about 1000-bp DNA region of phi g1e containing cpg and cng was inferred to function as a promoter/repressor system for the phi g1e lysogenic and lytic pathway.

Halothane, an inhalation anesthetic, activates protein kinase C and superoxide generation by neutrophils.

The rate of superoxide generation of guinea pig intraperitoneal neutrophils by a chemotactic peptide or 12-O-tetradecanoylphorbol-13-acetate (TPA) was increased by 2-bromo-2-chloro-1,1,1,-trifluoroethane (halothane), an inhalation anesthetic. This increase was inhibited by 1-(5-isoquinolinesulfonyl)methylpiperazine dihydrochloride (H-7), a specific inhibitor of Ca2+- and phospholipid-dependent protein kinase C (PKC). Halothane was found to significantly activate partially purified PKC. The activation required phosphatidylserine (PS) and Ca2+. Dioleoylglycerol- or TPA-activated PKC activity was further increased by halothane. The cytoplasmic proteins of guinea pig neutrophils phosphorylated by halothane-activated PKC were similar to those phosphorylated by PMA-activated PKC. The phosphorylation of a 48 kDa protein, a phosphorylated protein required for NADPH oxidase activation, was also increased by halothane. These data suggest that the increase of superoxide production by halothane is correlated with its activation of PKC.

Changes of chemoarchitectural organization of the rat spinal cord following ventral and dorsal root transection.

Time-related changes in the distribution of chemical messengers in the rat spinal cord following the transection of dorsal and ventral roots were observed by using immunohistochemistry for the following antigens: microtubule-associated protein 2 (MAP2), calcitonin gene-related peptide (CGRP), substance P (SP), galanin (Gal), Met-enkephalin (Enk), neuropeptide Y (NPY), and serotonin (5-HT). To investigate dendrocytoarchitectonic organizational changes, morphometric analyses were performed on both the gray and the white matter of tissue samples stained with MAP2 antiserum. A significant reduction in the area of gray matter on the lesioned side was seen from 1 to 24 weeks postoperation, and progressive changes in the shape of the gray matter were also observed. CGRP-immunoreactive fibers were reduced in number in the posterior horn after root transection, except in the lateral part of lamina I. In contrast, CGRP immunoreactivity in the anterior horn cells of the ipsilateral side was increased early after transection, but later it progressively decreased. Root transection also caused significant reduction in the number of SP-immunoreactive fibers in the posterior horn, but no changes were seen in the anterior horn. Gal immunoreactivity was also affected by root transection, and it changed in a similar way to CGRP immunoreactivity. 5-HT-immunoreactive fibers were increased in the posterior horn after transection, and later decreased. In the anterior horn, there were no changes in the intensity or distribution pattern of 5-HT-immunoreactive nerve fibers following root transection. Enk and NPY immunoreactivity in the anterior and posterior horns was not affected by root transection up to 24 weeks postoperative. These results show that spinal root transection caused significant changes in the chemoarchitectural organization of nerve fibers containing certain types of chemical messengers, such as CGRP, SP, Gal, and 5-HT, in addition to altering dendritic geometry in the spinal cord.

Brain natriuretic peptide in the porcine spinal cord: an immunohistochemical investigation of its localization and the comparison with atrial natriuretic peptide, substance P, calcitonin gene-related peptide, and enkephalin.

Immunohistochemistry was used to localize brain natriuretic peptide in the porcine spinal cord and to compare it with that of atrial natriuretic peptide, substance P, calcitonin gene-related peptide and [Met]enkephalin. Brain natriuretic peptide-immunoreactive varicose fibers were observed in lamina I and the inner portion of lamina II of the dorsal horn. Semiquantitative analysis showed that the highest density of brain natriuretic peptide-immunoreactive varicosities was in the lumbosacral and coccygeal segments. The distributional pattern of brain natriuretic peptide-immunoreactive nerve fibers in the spinal cord was unique and quite distinct from that of the other neuropeptides studied. These neuroanatomical findings suggest that brain natriuretic peptide may play a role in the regulation of nociceptive processing in the spinal cord, either alone or with bioactive substances.

Tissue-specific gene expression of heme oxygenase-1 (HO-1) and non-specific delta-aminolevulinate synthase (ALAS-N) in a rat model of septic multiple organ dysfunction syndrome.

Reactive oxygen species are thought to be involved in the pathogenesis of septic multiple organ dysfunction syndrome (MODS). It has been reported that heme oxygenase-1 (HO-1) (EC 1.14.99.3) is induced in septic animal models and is thought to confer protection against oxidative tissue injury. In this study, we examined changes in gene expression of HO-1 and non-specific delta-aminolevulinate synthase (ALAS-N) (EC 2.3.1.37), the rate-limiting enzymes in heme catabolism and heme synthesis, respectively, after intraperitoneal administration of bacterial lipopolysaccharide (LPS) to rats. LPS treatment caused the elevation of body temperature, increases in white blood cell counts, and marked elevation of serum interleukin-6 levels associated with liver, lung, and kidney injuries, characteristic of septic MODS. LPS administration significantly induced HO-1 mRNA, protein, and enzyme activity in the liver, lung, and kidney. In contrast, ALAS-N mRNA was decreased rapidly in the liver, followed by an oscillating recovery pattern. Induction of hepatic HO-1 mRNA and rapid suppression of ALAS-N mRNA were likely the result of a rapid increase in hepatic free heme concentration as judged by the increase in heme saturation of tryptophan pyrrolase. In contrast to that in the liver, the ALAS-N mRNA level in the lung and kidney was increased significantly after LPS administration, suggesting a novel mechanism of ALAS-N regulation in these tissues. These findings suggest that HO-1 and ALAS-N mRNA are regulated in a tissue-specific manner in a rat model of septic MODS.

Differential effects of isoflurane and halothane on the induction of heat shock proteins.

Isoflurane is considered to be a less hepatotoxic volatile anesthetic than halothane since it not only undergoes quantitatively much less metabolism to form toxic reactive intermediates, but also preserves better hepatic blood flow. However, the biochemical basis for the reduced hepatotoxicity has not been elucidated. In this study, we examined the induction of two heat shock proteins, heat shock protein 70 (HSP70) and heme oxygenase-1 (HO-1), in the livers of rats pretreated with or without phenobarbital, followed by exposure to isoflurane or halothane under hypoxic conditions. In the phenobarbital-pretreated rats, the maximal induction of HSP70 was observed by halothane-hypoxia treatment, followed by a half-maximal induction by isoflurane-hypoxia treatment, and less than 30% induction by hypoxia treatment alone. Serum alanine aminotransferase (ALT) activity, an indicator of hepatic dysfunction, which correlated well with the extent of centrilobular necrosis, showed similar changes with increases in HSP70 mRNA. In contrast, HO-1 mRNA was induced only by treatment with halothane-hypoxia. In addition, changes in the expression of HSP70 and HO-1 mRNAs were correlated with their protein expression in the liver. In non-pretreated rats, neither isoflurane-hypoxia exposure nor halothane-hypoxia exposure caused apparent hepatic injury. There was also no induction of HSP70 or HO-1 mRNA by these treatments in non-pretreated animals. These findings demonstrate that there is a significant difference in hepatic injury, and in the induction of HO-1 and HSP70 between halothane-hypoxia and isoflurane-hypoxia treatments. Isoflurane is known to be safer than halothane, which may, in part, be accounted for by the generation of less oxidative stress in the presence of isoflurane, as assessed by reduced induction of heat shock proteins compared with halothane treatment.

Prevention of halothane-induced hepatotoxicity by hemin pretreatment: protective role of heme oxygenase-1 induction.

Reductive metabolism of halothane in phenobarbital-pretreated rats is known to increase free radical formation that results in hepatotoxicity. It also is associated with a marked induction of microsomal heme oxygenase-1 (HO-1), suggesting that there is an alteration in heme metabolism. In this study, we examined heme metabolism in rats pretreated with phenobarbital, followed by exposure to halothane-hypoxia. In this model, there was a significant decrease in microsomal cytochrome P450 content in the liver, followed by a rapid increase in free heme concentration and a decrease in the level of mRNA for the nonspecific delta-aminolevulinate synthase. A transient but dramatic induction of HO-1 mRNA and a prolonged induction of heat shock protein 70 mRNA also occurred. The HO-1 protein was detected principally in the hepatocytes around the central vein. Serum alanine transaminase (ALT) activity, an indicator of hepatic dysfunction, increased continuously throughout the experiment. Hemin pretreatment induced hepatic HO-1 with abrogation of the halothane-induced hepatotoxicity in this model, as judged by ALT activity and normal histology. Our findings in this study thus indicate that halothane-induced hepatotoxicity is due not only to its reductive metabolite formation, but also to an increase in hepatic free heme concentration, which is a potent prooxidant; HO-1 induction is an important protective response against such changes. This is also the first study to demonstrate that hemin pretreatment, which induces HO-1 prior to exposure to halothane, effectively prevents halothane-induced hepatotoxicity.