Isolation and characterization of a cDNA from the rat brain that encodes hemoprotein heme oxygenase-3

Two isozymes of heme oxygenase (HO), HO-1 or HSP32 and the constitutive form HO-2, have been characterized to date. We report the discovery of a third protein species and refer to it as HO-3. HO-3 is the product of a single transcript of approximately 2.4 kb and can encode a protein of approximately 33 kDa. The HO-3 transcript is found in the spleen, liver, thymus, prostate, heart, kidney, brain and testis and is the product of a single-copy gene. The predicted amino acid structure of HO-3 differs from both HO-1 (HSP32) and HO-2 but is closely related to HO-2 (approximately 90%). Escherichia coli expressed and purified HO-3 protein does not cross react with polyclonal antibodies to either rat HO-1 or HO-2, is a poor heme catalyst, and displays hemoprotein spectral characteristics. The predicted protein has two heme regulatory motifs that may be involved in heme binding. These motifs and the hemoprotein nature of HO-3 suggest a potential regulatory role for the protein in cellular processes which are heme-dependent.

Heme oxygenase-2 is a hemoprotein and binds heme through heme regulatory motifs that are not involved in heme catalysis

The heme oxygenase (HO) system degrades heme to biliverdin and CO and releases chelated iron. In the primary sequence of the constitutive form, HO-2, there are three potential heme binding sites: two heme regulatory motifs (HRMs) with the absolutely conserved Cys-Pro pair, and a conserved 24-residue heme catalytic pocket with a histidine residue, His151 in rat HO-2. The visible and pyridine hemochromogen spectra suggest that the Escherichia coli expressed purified HO-2 is a hemoprotein. The absorption spectrum, heme fluorescence quenching, and heme titration analysis of the wild-type protein versus those of purified double cysteine mutant (Cys264/Cys281 --> Ala/Ala) suggest a role of the HRMs in heme binding. While the His151 --> Ala mutation inactivates HO-2, Cys264 --> Ala and Cys281 --> Ala mutations individually or together (HO-2 mut) do not decrease HO activity. Also, Pro265 --> Ala or Pro282 --> Ala mutation does not alter HO-2 activity. Northern blot analysis of ptk cells indicates that HO-2 mRNA is not regulated by heme. The findings, together with other salient features of HO-2 and the ability of heme-protein complexes to generate oxygen radicals, are consistent with HO-2, like five other HRM-containing proteins, having a regulatory function in the cell.

Effects of moisture content and endodontic treatment on some mechanical properties of human dentin

The objective of this study was to determine whether significant differences exist between the mechanical properties of human dentin from treated pulpless teeth and dentin from normal vital teeth. Dentin specimens (n = 262) were obtained from 54 freshly extracted normal vital human teeth and 24 treated human pulpless teeth. These specimens were subjected to different experimental conditions (wet, air dried, desiccated, and rehydrated). Compression, indirect tensile, and impact tests were conducted to measure the mechanical properties of those specimens. All data obtained were analyzed with t tests. The results showed that the dehydration of dentin increases the Young's modulus, proportional limit (in compression), and especially the ultimate strength (in both compression and tension). Substantial dehydration changes the fracture characteristics of dentin specimens under static compressive and indirect tensile loadings. The measurements of impact-breaking energies of desiccated dentin were not found to be significantly decreased. The compressive and tensile strengths of dentin from treated pulpless teeth obtained in this study do not appear to be significantly different from those of normal dentin (p > 0.05), while the mean values of Young's modulus and proportional limit in compression tests appear to be lower. Fifty percent of the dentin specimens from treated pulpless teeth exhibit greater plastic deformation than normal dentin in compression. The results of this study do not support the theory that dehydration after endodontic treatment per se weakens dentin structure in terms of compressive and tensile strengths. Other mechanical properties of treated pulpless teeth, however, may not be the same as those of normal vital teeth.

Allergen-specific Th1 cells counteract efferent Th2 cell-dependent bronchial hyperresponsiveness and eosinophilic inflammation partly via IFN-gamma

Th2 T cell immune-driven inflammation plays an important role in allergic asthma. We studied the effect of counterbalancing Th1 T cells in an asthma model in Brown Norway rats that favors Th2 responses. Rats received i.v. transfers of syngeneic allergen-specific Th1 or Th2 cells, 24 h before aerosol exposure to allergen, and were studied 18-24 h later. Adoptive transfer of OVA-specific Th2 cells, but not Th1 cells, and OVA, but not BSA exposure, induced bronchial hyperresponsiveness (BHR) to acetylcholine and eosinophilia in a cell number-dependent manner. Importantly, cotransfer of OVA-specific Th1 cells dose-dependently reversed BHR and bronchoalveolar lavage (BAL) eosinophilia, but not mucosal eosinophilia. OVA-specific Th1 cells transferred alone induced mucosal eosinophilia, but neither BHR nor BAL eosinophilia. Th1 suppression of BHR and BAL eosinophilia was allergen specific, since cotransfer of BSA-specific Th1 cells with the OVA-specific Th2 cells was not inhibitory when OVA aerosol alone was used, but was suppressive with OVA and BSA challenge. Furthermore, recipients of Th1 cells alone had increased gene expression for IFN-gamma in the lungs, while those receiving Th2 cells alone showed increased IL-4 mRNA. Importantly, induction of these Th2 cytokines was inhibited in recipients of combined Th1 and Th2 cells. Anti-IFN-gamma treatment attenuated the down-regulatory effect of Th1 cells. Allergen-specific Th1 cells down-regulate efferent Th2 cytokine-dependent BHR and BAL eosinophilia in an asthma model via mechanisms that depend on IFN-gamma. Therapy designed to control the efferent phase of established asthma by augmenting down-regulatory Th1 counterbalancing mechanisms should be effective.

Mechanisms of inherited deficiencies of multiple UDP-glucuronosyltransferase isoforms in two patients with Crigler-Najjar syndrome, type I

Crigler-Najjar syndrome, type I (CN-I) is a potentially lethal disorder characterized by severe unconjugated hyperbilirubinemia resulting from a recessively inherited deficiency of hepatic UDP-glucuronosyl-transferase (UGT) activity toward bilirubin (B-UGT). Two forms of B-UGT exist in human liver. mRNAs for these two forms and that for another isoform with activity toward simple phenols (P-UGT) have unique 5' regions, but their 3' regions are identical. The three mRNA species are derived from a single locus; the unique 5' regions are encoded by single unique exons and the identical 3' regions consist of four consecutive exons that are shared by all three isoforms. In this paper, we determined genetic lesions in two CN-I patients with deficiency of hepatic B-UGT and P-UGT activities. In one patient, there was a C----T substitution in exon 4 (common region) predicting the substitution of a serine residue with a phenylalanine residue; this mutation was present in the identical region of B-UGT and P-UGT mRNAs. In the other patient, a C----T substitution in exon 2 (common region) of the B-UGT/P-UGT locus resulted in a premature stop codon. This exon (132 nt) was absent in heptic B-UGT and P-UGT mRNAs of this patient due to exon skipping during pre-mRNA processing. Sequence abnormality of three distinct mRNA species explains the abnormality of multiple UGT isoforms in these patients. Presence of identical abnormalities in the common regions of the three mRNAs is consistent with the finding that the common 3' regions of the two B-UGT mRNAs and the P-UGT mRNA are encoded by four shared exons.

Overexpression of the c-met protooncogene in human gastric carcinoma--correlation to clinical features

Overexpression of hepatocyte growth factor receptor (c-met) has been detected in many human tumors. To investigate the possible involvement of c-met in human gastric carcinogenesis, we examined c-met expression in 45 patients with gastric carcinoma using Northern blot analysis, reverse transcription-polymerase chain reaction (RT-PCR), and immunohistochemical staining. The c-met mRNA expression was increased twofold and sevenfold in gastric carcinoma tissues compared to the adjacent normal tissues by Northern blot analysis and RT-PCR, respectively. In the immunohistochemical study, c-met protein was detected in 32 of 45 (71.1%) patients, with marked overexpression in gastric carcinoma compared with matched normal gastric tissues. The c-met-positive immunoreactivities were more frequently encountered in serosa-exposed and serosa-infiltrating gastric cancer (p = 0.003). In addition, tumor stage was another statistically significant parameter that was observed between the two groups (p = 0.02). Multivariate analyses revealed that the tumor stage (p = 0.014) and c-met overexpression (p = 0.031) were independently correlated with survival. These data suggest that overexpression of c-met may play a part in gastric carcinogenesis and may represent a prognostic factor for gastric cancer.

Involvement of cysteinyl leukotrienes in airway smooth muscle cell DNA synthesis after repeated allergen exposure in sensitized Brown Norway rats

Airway smooth muscle thickening is a characteristic feature of airway wall remodelling in chronic asthma. We have investigated the role of the leukotrienes in airway smooth muscle (ASM) and epithelial cell DNA synthesis and ASM thickening following repeated allergen exposure in Brown Norway rats sensitized to ovalbumin. There was a 3 fold increase in ASM cell DNA synthesis, as measured by percentage bromodeoxyuridine (BrdU) incorporation, in repeatedly ovalbumin-exposed (4.1%, 3.6-4.6; mean, 95% c.i.) compared to chronically saline-exposed rats (1.3%, 0.6-2.1; P<0.001). Treatment with a 5-lipoxygenase enzyme inhibitor (SB 210661, 10 mg kg(-1), p.o.) and a specific cysteinyl leukotriene (CysLT1) receptor antagonist, pranlukast (SB 205312, 30 mg kg(-1), p.o.), both attenuated ASM cell DNA synthesis. Treatment with a specific leukotriene B4 (BLT) receptor antagonist (SB 201146, 15 mg kg(-1), p.o.) had no effect. There was also a significant, 2 fold increase in the number of epithelial cells incorporating BrdU per unit length of basement membrane after repeated allergen exposure. This response was not inhibited by treatment with SB 210661, pranlukast or SB 201146. A significant increase in ASM thickness was identified following repeated allergen exposure and this response was attenuated significantly by SB 210661, pranlukast and SB 201146. Rats exposed to chronic allergen exhibited bronchial hyperresponsiveness to acetylcholine and had significant eosinophil recruitment into the lungs. Treatment with SB 210661, pranlukast or SB 201146 significantly attenuated eosinophil recruitment into the lungs, whilst having no significant effect on airway hyperresponsiveness. These data indicate that the cysteinyl leukotrienes are important mediators in allergen-induced ASM cell DNA synthesis in rats, while both LTB4 and cysteinyl leukotrienes contribute to ASM thickening and eosinophil recruitment following repeated allergen exposure.

Complications in thoracoscopic spinal surgery: a study of 90 consecutive patients

BACKGROUND

The literature contains few reports on negative outcomes after thoracoscopic spinal surgery.

METHODS

From November 1995 to February 1998, 90 patients underwent minimally invasive spinal surgery by thoracoscopic assistance as treatment for their anterior spinal lesions. The diagnoses included 41 spinal metastases, 13 cases of scoliosis, 12 burst fractures, 10 cases of tuberculous spondylitis, 8 cases of pyogenic spondylitis, 2 thoracic disc herniations, 2 cases of ankylosing spondylitis with discitis, 1 osteoporotic compression fracture, and 1 case of thoracolumbar kyphosis. The procedures included biopsy only (3 patients); thoracic discectomy (3 patients); multilevel anterior releases, discectomy, and fusion (14 patients); corpectomy for decompression (6 patients); corpectomy and interbody fusion (32) patients; and internal instrumentation (28 patients).

RESULTS

A total of 30 complications were noted in 22 patients (24.4%). Two fatal complications occurred, resulting from massive blood transfusion in one case and postoperative pneumonia in another. Other nonfatal complications included four cases of transient intercostal neuralgia, three superficial wound infections, three cases of pharyngeal pain, two cases of lung atelectasis, two cases of residual pneumothorax, two cases of subcutaneous emphysema, one inadvertent pericardial penetration due to adhesion, one chylothorax that resolved after conservative management, one vertebral screw malposition, and one graft dislodgement that needed late revision surgery. Three patients required ventilatory support for longer than 72 hours. Five patients with spinal metastases had an estimated intraoperative blood loss of more than 2,000 ml. No injury to the internal organs or spinal cord was observed. There were four conversions to open procedures due to two cases of severe pleural adhesions and two poorly tolerated one-lung ventilation. At the latest follow-up, nine patients had died as a result of cancer dissemination.

CONCLUSIONS

(a) Well-selected patients and attention to details are essential to optimizing surgical results. (b) A refined technique for less invasive tumor surgery has been developed. (c) Surgeons had better experience with the standard anterior spinal approach and showed no hesitation in converting to an open procedure when necessary. A procedure failure does not mean a treatment failure.

Adoptive transfer of allergen-specific CD4+ T cells induces airway inflammation and hyperresponsiveness in brown-Norway rats

Following allergen exposure, sensitized Brown-Norway rats develop airway hyperresponsiveness (AHR) and eosinophilic inflammation together with an increase in activated T cells (CD25+) in the airways. We tested the hypothesis that CD4+ T cells are involved directly in the acquisition of AHR. Spleen T cells from animals that were injected intraperitoneally on three consecutive days with ovalbumin/Al(OH)3, showed a dose-dependent proliferative response in vitro to ovalbumin, but not to bovine serum albumin, as measured by [3H]thymidine uptake. For total T-cell transfer, spleen cells obtained from donor rats 4 days after sensitization were depleted of adherent cells by a nylon wool column separation. CD4+ and CD8+ T cells were purified by immunomagnetic beads cell separation. Recipient naive rats were injected intravenously with 50 x 10(6) total T cells, 20 x 10(6) and 5 x 10(6) CD4+ cells, and 5 x 10(6) CD8+ cells, and were exposed to ovalbumin aerosol 24 hr afterwards. After a further 24 hr, airway responsiveness to acetylcholine (ACh) was measured and provocative concentration (PC) values PC100, PC200 and PC300) (the ACh concentration needed to achieve 100, 200 and 300% increase in lung resistance above baseline) were calculated. Airway responsiveness was significantly increased in recipients of sensitized total T cells compared with recipients of cells from saline-injected donor rats (P < 0.05). There were significantly increased eosinophil major basic protein (MBP)+ cell counts/mm2 in airway submucosal tissue in the hyperreactive rats and a significant correlation was found between the number of MBP+ cells and PC100 (r = 0.75; P < 0.03) in recipients of sensitized total T cells. Purified CD4+ T cells from sensitized donors induced AHR in naive recipients (P < 0.05), while sensitized CD8+ and naive CD4+ cells failed to do so. Our data indicate that T cells may induce AHR through an eosinophilic airway inflammation and that CD4+ T cells may have a direct effect in this process in Brown-Norway rats.

Expression of Th-2 cytokines interleukin-4 and -5 and of Th-1 cytokine interferon-gamma in ovalbumin-exposed sensitized Brown-Norway rats

We determined the expression of Th-2 type cytokines, interleukin-4 (IL-4) and IL-5, and of the Th-1 type cytokine, interferon-gamma (IFN-gamma), in the Brown-Norway rat. Rats were intraperitoneally sensitized with ovalbumin and 21 days later were either exposed to ovalbumin or saline aerosol. The value -log PC300 (PC300 = concentration of acetylcholine needed to increase baseline lung resistance by 300%) was 2.49 +/- 0.15 in sensitized, exposed rats, was higher than in sensitized, saline-exposed or naive rats (1.54 +/- 0.27 and 1.63 +/- 0.06 respectively, P < 0.05). There was a significant increase in eosinophils in bronchoalveolar lavage fluid and in airway submucosal airway tissues in the sensitized exposed group. Reverse-transcriptase polymerase chain reaction was performed on total lung RNA using primers for IL-4, IL-5, IFN-gamma and beta-actin. IL-4 and IL-5 mRNA levels in control and sensitized saline-exposed rats were not detectable, but increased levels were found in sensitized and ovalbumin-exposed rats with levels of 0.25 +/- 0.01 and 0.98 +/- 0.02% of beta-actin mRNA as assessed by densitometric measurements. Expression of IFN-gamma mRNA was significantly reduced in sensitized and ovalbumin-exposed rats. As in asthmatic airways, there is an increased expression of Th-2 cytokines, IL-4 and IL-5, together with a reduction in the Th-1 cytokine, IFN-gamma, thus supporting a role for Th-2 cytokines in allergic eosinophilic inflammation.

Human biliverdin IXalpha reductase is a zinc-metalloprotein. Characterization of purified and Escherichia coli expressed enzymes

Biliverdin IXalpha reductase (BVR) catalyzes the conversion of the heme b degradation product, biliverdin, to bilirubin. BVR is unique among enzymes characterized to date in that it has dual pH/cofactor (NADH, NADPH) specificity. A cDNA clone encoding human BVR was isolated from a gamma library using a probe generated via reverse transcription and the polymerase chain reaction from human placental RNA. This approach was taken because the more direct approach of using the previously isolated rat BVR cDNA as the hybridization probe did not succeed. The human cDNA was cloned and sequenced; it was shown to have an open reading frame encoding a 296-amino-acid protein in which could be identified four peptides previously identified by micro-sequencing purified protein. The cDNA hybridized with a single message of approximately 1.2 kb in human kidney poly(A)-rich RNA, and appeared, by Southern blot analysis, to be the product of a single-copy gene. Sequence analysis indicated that the human reductase shows approximately 83% identity, at both the nucleotide and amino acid levels, with rat BVR. In some regions including the carboxyl terminus, protein sequence identity drops to 45%. Also noteworthy is the presence of two additional cysteine residues in the encoded human reductase (five compared to three for rat). The protein produced by an expression plasmid in which the insert was cloned in frame with lacZ sequences was characterized, and demonstrated dual pH and cofactor dependence. However, as suggested by kinetic analysis, the human enzyme may also use NADH as cofactor, as opposed to the rat reductase, which most likely utilizes only NADPH under physiological conditions. Western blot analysis and isoelectric focusing demonstrate that, although migrating as a single band on SDS/PAGE, the expressed protein, like that purified from tissue, consists of several isoelectric charge variants. Atomic absorption spectroscopy indicates that the protein purified from human liver contains Zn at an approximately 1:1 molar ratio. That human BVR is a Zn metalloprotein was further substantiated by 65Zn exchange analysis of both the purified and the fusion protein expressed in Escherichia coli. Exogenous Zn also inhibits NADPH-dependent, but not NADH-dependent, activity. Hence, the NADH and NADPH binding regions are differentiated by their ability to interact with Zn; Fe-hematoporphyrin, however, inhibited both NADH- and NADPH-dependent activity.

Alcohol, betel-nut and cigarette consumption are negatively associated with health promoting behaviors in Taiwan: a cross-sectional study

Background

Oral cancer is the 2^nd most common cause of death due to cancer in the south-western coastal region of Taiwan; the standardized mortality of oral cancer is higher than elsewhere in the world. According to the evidence, alcohol, betel-nut and cigarette (ABC) consumption cause oral, nasopharyngeal and related cancers. This study describes the relationships between ABC consumers and health promoting behaviors among community adults living around an area with a high prevalence of oral cancer.

Methods

A population-based, cross-sectional study design was conducted in oral cancer epidemic areas in south-western coastal Taiwan in 2010, 6,203 community residents over 20 years of age participated. Demographic data, ABC habits, and health-promoting behaviors were explored. A logistic regression analyses were used to identify factors associated with ABC consumers.

Results

A high percentage of participants consumed alcohol, betel-nut and cigarettes. Betel-nut and cigarette consumers took low levels of exercise, adopted a poor diet, and had poor oral hygiene. After adjusting for potential confounders, the logistic regression model indicated that middle aged males of poor education and low economic status, who did not exercise regularly and had poor oral hygiene, were more likely to chew betel quid and smoke cigarettes.

Conclusions

It has identified that BC consumers are negatively associated with health promoting behaviors. Further research is required to understand the reasons why the subjects consume ABC, and explore ways to prevent initiation and enhance cessation of ABC habits in this population.

Role of cytokine-induced neutrophil chemoattractant (CINC) in ozone-induced airway inflammation and hyperresponsiveness

Cytokine-induced neutrophil chemoattractant (CINC) is a rat chemokine with potent chemoattractant effects on neutrophils. We determined the involvement of CINC in ozone-induced airway neutrophilia and bronchial hyperresponsiveness (BHR) in the rat. We found a marked increase in lung CINC messenger RNA (mRNA) within 2 h after cessation of ozone exposure (1 ppm for 3 h), as measured by Northern blot analysis, whereas rats exposed to room air had no detectable CINC mRNA. Ozone exposure induced a significant neutrophilia in bronchoalveolar lavage fluid (BALF) at 24 h after exposure (air-exposed rats: 4.2 +/- 2.0 x 10(4), versus ozone-exposed rats: 16.1 +/- 3.7 x 10(4)); prior treatment with a goat anti-CINC antibody (1 mg, intravenously) suppressed the neutrophilia (3.1 +/- 0.9 x 10(4)). When administered intratracheally, the antibody (230 micrograms) partially inhibited the influx of neutrophils. The increase in bronchial responsiveness to acetylcholine observed after ozone exposure was not inhibited by the anti-CINC antibody. The anti-CINC antibody (1 mg, intravenously) also inhibited BALF neutrophilia induced by exposure to a higher concentration of ozone (3 ppm, 3 h), without an effect on BHR. CINC is an important chemokine causing ozone-induced neutrophil chemoattraction, but is not involved in the induction of ozone-induced BHR. The neutrophil is unlikely to contribute to BHR in this model.

Molecular characterization of germline mutations in the BRCA1 and BRCA2 genes from breast cancer families in Taiwan

A total of 18 families with multiple cases of breast cancer were identified from southern Taiwan, and 5 of these families were found to carry cancer-associated germline mutations in the BRCA1 and BRCA2 genes. One novel cryptic splicing mutation of the BRCA1 gene, found in two unrelated families, was shown to be a deletion of 10 bp near the branch site in intron 7. This mutation causes an insertion of 59 nucleotides derived from intron 7 and results in a frameshift, leading to premature translational termination of BRCA1 mRNA in exon 8. Deletions of 2670delC, 3073delT and 6696-7delTC in the BRCA2 gene were found in three other breast cancer families. All three deletions are predicted to generate frameshifts and to result in the premature termination of BRCA2 protein translation. Several genetic polymorphisms in both BRCA1 and BRCA2 genes were also detected in this investigation.

Ankle arthrodesis with cross screw fixation. Good results in 36/40 cases followed 3-7 years

Tibiotalar arthrodesis by an anterior approach, using internal compression with cancellous crews, offers wide exposure, good possibilities of correcting deformities, and good bony apposition. From 1987 to 1991, we used this technique in 42 ankle joints (40 patients). The indications were posttraumatic arthrosis, sequelae of septic arthritis, necrosis of the talus and failed ankle arthrodesis. In 13 ankles with severe deformity, a bone graft was also used. 38 patients (40 ankle joints) were available for follow-up after 4 (3-7) years. Solid union was achieved in 38 ankles after an average of 13 weeks. The clinical result was good-to-excellent in 36 ankles. We conclude tha this is a simple and effective method for ankle arthrodesis in both low-risk and, coupled with bone grafting, in properly selected high-risk patients.

Treatment of the femoral neck amd trochanteric benign lesions

Thirty-five patients with a benign lesion of the femoral neck or trochanter were treated and seen in followup at the authors' institution from 1988 to 1991. Sixteen men and 19 women between the ages of 18 and 54 years (average, 27 years) were seen at an average followup of 3 years 6 months (range, 2-5 years). Eight patients had aneurysmal bone cyst; 14 had monostotic fibrous dysplasias; 2 had giant cell tumors; and 11 had simple bone cysts. Eleven patients had pathologic fractures. All patients were treated with curettage and bone grafting in conjunction with a sliding hip compression screw and plate. The bone grafting included a combination of a deep frozen allogenic cortical strut with autogenous iliac cancellous bone to fill the remaining defect space after lag screw and cortical strut had been implanted. At followup, all patients had good bony healing and incorporation of the implanted graft. There were no complications and no local recurrences. All of the functional results were excellent.

Heme oxygenase-2 interaction with metalloporphyrins: function of heme regulatory motifs

Heme oxygenase-2 (HO-2) degrades heme [Fe-protoporphyrin IX (Fe-PP)] to CO and bilirubin. The enzyme is a hemoprotein and interacts with nitric oxide. HO-2 has two copies of heme regulatory motif (HRM) with a conserved core of Cys264-Pro265 and Cys281-Pro282. We examined interaction of HO-2 HRMs with Fe-PP, Zn-protoporphyrin IX (Zn-PP; HO-2 inhibitor), and protoporphyrin IX (PP IX). Spectral analyses, using 1:4 or 1:1 molar ratio of the heme to 10-residue peptides, corresponding to HRM containing HO-2 sequences, revealed specific interactions as indicated by a shift in the absorption spectrum of heme. Five residue peptides qualitatively produced similar results. Substitution of cysteine with alanine in either peptide eliminated interactions, and substitution of proline with alanine reduced the peptides' affinity for heme. Neither Zn-PP nor PP IX absorption spectrum was affected by HRM peptides. The circular dichroism spectra confirmed heme-HRM peptides interactions. An astounding 4,000-6,000-fold higher concentrations of KCN were required at pH 7.5 to displace HRM peptides from heme. Data suggest (a) each HRM can contribute to HO-2-heme interaction, (b) heme iron interacts with cysteine thiol, (c) charged residues upstream of Cys264-Pro265 result in its high-affinity heme binding, and (d) inhibition of HO-2 activity by synthetic metalloporphyrins does not involve HRMs. We suggest that heme bound to HRMs may serve as a binding site/reservoir for gaseous signal molecules.

Contribution of bradykinin B(1) and B(2) receptors in allergen-induced bronchial hyperresponsiveness

Bradykinin (BK) is a peptide mediator generated at sites of inflammation and its effects are mediated through constitutively expressed B(2) receptor or through induction of B(1) receptors. We examined the role of these receptors in bronchial hyperresponsiveness (BHR). Brown-Norway rats sensitized with ovalbumin (OA) and Al(OH)(3) intraperitoneally, were exposed 3 wk later to either saline or OA aerosol. B(1) receptor antagonist desArg(10)[Hoe140] (200 nmol/kg or 1 micromol/kg, intraperitoneally) or B(2) receptor antagonist Hoe140 (200 nmol/kg, intraperitoneally) was administered 30 min before allergen exposure. Hoe140 had no effect on OA-induced BHR to acetylcholine (ACh) and bronchoalveolar lavage fluid (BALF) cellular profiles, but inhibited bronchoconstriction to BK (p < 0.04). At both doses, desArg(10)[Hoe140] dose-dependently inhibited allergen-induced BHR to ACh (p < 0.01), but had no effect on bronchoconstriction to BK or baseline ACh responsiveness. The inflammatory cells in BALF were not affected apart from reduced lymphocyte numbers at the highest dose. B(1) receptor mRNA expression measured by Northern analysis was increased after allergen exposure in sensitized lungs, with a peak at 2 to 6 h after exposure, whereas B(2) receptor mRNA expression remained unchanged. Newly induced BK B(1) receptors may be involved in allergen-induced BHR to ACh, whereas constitutive B(2) receptors mediate BK-induced bronchoconstriction.

Effect of CD8+ T-cell depletion on bronchial hyper-responsiveness and inflammation in sensitized and allergen-exposed Brown-Norway rats

We examined the role of CD8+ T cells in a Brown-Norway rat model of asthma, using a monoclonal antibody to deplete CD8+ T cells. Ovalbumin (OA)-sensitized animals were given anti-CD8 antibody (0.5 mg/rat) intravenously 1 week prior to exposure to 1% OA aerosol and were studied 18-24 hr after aerosol exposure. Following administration of anti-CD8 antibody, CD8+ cells were reduced to <1% of total lymphocytes in whole blood and in spleen. In sensitized animals, OA exposure induced bronchial hyper-responsiveness (BHR), accumulation of eosinophils, lymphocytes and neutrophils in bronchoalveolar lavage (BAL) fluid, and also an increase in tissue eosinophils and CD2+, CD4+ and CD8+ T cells in airways. Anti-CD8 antibody caused a further increase in allergen-induced BHR (P<0.03, compared with sham-treated animals), together with a significant increase in eosinophil number in BAL fluid (P<0.05). While CD2+ and CD4+ T cells in airways were not affected by anti-CD8 treatment, the level of CD8+ T cells was significantly reduced in sensitized, saline-exposed animals (P<0.04, compared with sham-treated rats), and sensitized and OA-challenged rats (P<0.002, compared with sham-treated rats). Using reverse transcription-polymerase chain reaction, an increase of T helper (Th)2 cytokine [interleukin (IL)-4 and IL-5], and also of Th1 cytokine [interferon-gamma (IFN-gamma) and IL-2], mRNA in the lung of sensitized and OA-exposed animals was found; after CD8+ T-cell depletion, Th1 cytokine expression was significantly reduced (P<0.02), while Th2 cytokine expression was unchanged. CD8+ T cells have a protective role in allergen-induced BHR and eosinophilic inflammation, probably through activation of the Th1 cytokine response.

Clinicopathologic study of advanced gastric cancer without serosal invasion in young and old patients

Fifty-seven patients treated by radical gastric resections were retrospectively studied to understand the clinicopathologic characteristics of advanced gastric cancer without serosal invasion (the depth of tumor invasion limited to the muscularis propria or subserosal layer) in young and old age persons. There were 36 patients in the old age group (age > 60 years) and 21 in the young age group (age < or = 40 years). The clinical and pathologic parameters for this study included sex, gross type, location, maximum tumor size, depth of invasion, lymph node metastasis, tumor stage, histologic type, and rate of curative resection. The old patients had a higher percentage of small tumors, subserosal invasion and lymph node metastasis, but these parameters were not significantly different from those of the young patients, nor did the sex ratio, gross type, location, and rate of curative resection show significant differences. The histologic feature was the only statistically significant parameter, determined by univariate and multivariate analyses. Poorly differentiated adenocarcinoma and signet ring cell carcinoma were detected in 10 (47.6%) and 4 (19.0%) of the 21 younger patients, respectively, while there were 4 (11.1%) and 2 (5.6%) in the old age group. Although the gastric cancer in young patients had more aggressive histologic characteristics than it did in elderly patients, survival rates between the two groups did not differ to any great degree. Our findings indicate that the prognosis for younger patients with advanced gastric cancer without serosal invasion was favorable when curative resection was performed.

Dexamethasone inhibits luteinizing hormone-induced synthesis of steroidogenic acute regulatory protein in cultured rat preovulatory follicles

The effect of dexamethasone on LH-induced synthesis of steroidogenic acute regulatory (StAR) protein was studied in a serum-free culture of preovulatory follicles. StAR protein is a steroidogenic tissue-specific, hormone-induced, rapidly synthesized protein previously shown to be involved in the acute regulation of steroidogenesis, probably by promoting the transfer of cholesterol to the inner mitochondrial membrane and the cytochrome P450 side-chain cleavage (P450(scc)) enzyme. Treatment of preovulatory follicles dissected from ovaries of cyclic adult rats on the morning of proestrus with LH for 24 h resulted in a dose-dependent increase in the level of StAR protein that reached a maximum at 10 ng LH/ml. This increase was associated with an increase in progesterone production. Treatment of the follicles with increasing concentrations (1-1000 ng/ml) of dexamethasone suppressed LH (10 ng/ml)-induced StAR protein levels and progesterone production in a dose-dependent manner. The amount of P450(scc) was not affected by this dexamethasone treatment, indicating that the loss of steroidogenic capacity was not a result of inhibition of P450(scc). Dexamethasone also decreased StAR protein levels and progesterone production induced by the adenylate cyclase activator forskolin (10(-5) M) or a cAMP analogue 8-Br-cAMP (0.5 mM). The effects of dexamethasone on 8-Br-cAMP-induced StAR protein levels and progesterone production were blocked by cotreatment of the follicles with glucocorticoid receptor antagonist RU-486. These results demonstrate that dexamethasone inhibits the LH-induced StAR protein levels and that the effects of dexamethasone are mediated by the glucocorticoid receptor.

The diagnostic value of galactography in patients with nipple discharge

To evaluate preoperative galactographic findings in the differentiation between the benign and malignant lesions in patients presenting spontaneous nipple discharge without mass. Of the 215 patients who have undergone the galactography, 181 cases with abnormal galactography had surgery performed. All galactrograms were reviewed and galactographic findings were correlated to the pathological results to determine diagnostic differentiation. Of the 181 cases we operated on, 112 cases were macroscopically bloody, with 30 cases having cancers (26.8%). Fifty-four cases with serous discharge had seven cancer cases (13.0%). No cancer cases with other color discharge were found. Of the 37 cancer cases, 11 cases had lesions located in the main mammary ducts (lactiferous duct and the segmental duct) (29.7%) and 26 cases had lesions in the peripheral ducts (the subsegmental duct and its branches) (70.3%) (P<.05). Of 113 cases with benign proliferative ductal lesions, 88 cases were located in the main mammary duct (77.9%) and 25 cases in the peripheral mammary duct (22.1%) (P<.05). Otherwise, 29 cancer cases (82.9%) had ductal obstructions and 28 cancer cases (75.7%) had irregular intraductal defects that appeared in the galactograms, which is different from the 113 benign proliferative ductal lesion cases that had 88 cases (71.7%) with ductal dilatation and 90 cases (79.6%) with lobular or smooth intraductal defects (P<.05). These results showed that the cancer cases had a higher rate of locating in the peripheral duct, irregular intraductal duct defects, and ductal obstruction, and a lower rate associated with ductal dilatation or torsion. The galactographic findings were evaluated using the tumor location, types of intraductal defects, ductal obstruction, and dilatation. Preoperative diagnostic galactography is useful in differentiating between the benign or malignant lesions in patients with spontaneous nipple discharge.

Endoscopic ultrasonography for preoperative locoregional staging and assessment of resectability in gastric cancer

We performed a prospective study from November 1989 to December 1996 to assess the accuracy of endoscopic ultrasonography (EUS) in the locoregional staging and resectability of patients with gastric carcinoma. One hundred and nineteen patients with gastric cancer who received preoperative assessment by EUS underwent subsequent surgery. The endosonographic tumor-node-metastasis (TNM) classification was used for comparison with the histopathologic findings of the resected specimens. The ability of EUS to accurately predict the T stage (depth of tumor invasion) and N stage (involvement of lymph node) was 70% and 65%, respectively. EUS displayed a tendency to overestimate T stage and underestimate N state. The differentiation of early gastric cancer from advanced gastric cancer showed a concordance rate of 89% and underestimation rate of 8% and underestimation rate of 3%. The accuracy of EUS in predicting the stage T1 to T3, which correspond to D0 resectability (no macroscopic or microscopic tumor remains), was 91%. In conclusion, these results revealed EUS as a valuable tool for evaluating the local staging and resectability of gastric cancer. We suggest that EUS should be introduced in the preoperative assessment of patients with gastric cancer.

Intraperitoneal hemorrhage due to spontaneous rupture of hepatocellular carcinoma: treatment by hepatic artery embolization

Seventeen patients with intraperitoneal hemorrhage due to spontaneous rupture of hepatocellular carcinoma were treated by emergency transcatheter arterial embolization. Fine-needle aspiration cytology was used to establish the histologic diagnosis in 11 patients with no history of hepatic malignancy. The other six patients had a pathologic confirmation of hepatic malignancy by open biopsy before admission. Pretreatment angiography showed extravasation of contrast material from the hepatic tumor in four patients (24%). In the other 13 patients, only hypervascular tumors were seen. Successful hemostasis was achieved in all patients. Fourteen patients survived after the embolization; the other three died immediately after embolization. Of the 14 patients, 11 died later (survival time ranged from 16 to 386 days). The remaining three patients are still alive at 3, 7, and 15 months, respectively, after the procedure. No serious complications related to embolization were encountered. Most patients had pain and fever. We conclude that emergency arterial embolization is an effective alternative to surgery for hepatic hemostasis in patients with spontaneous rupture of hepatocellular carcinoma.