Suppression of cellular immunity by surgical stress

BACKGROUND

Suppression of cellular immunity is one of the host responses to surgical stress. In cancer patients this immunosuppression may accelerate the growth and metastasis of residual cancer cells, so it is desirable to restrict immunosuppression by surgical stress to a minimum. However, the extent and duration of immunosuppression caused by operations on gastrointestinal cancer, as well as the mechanisms involved, have not been determined.

METHODS

To clarify these points, we investigated immunocyte function and measured the blood levels of hormones, cytokines, and acute phase reactants from before to after operation in 20 patients with stage I gastrointestinal cancer.

RESULTS

In patients exposed to surgical stress, peripheral blood lymphocyte numbers and function were suppressed until at least 2 weeks postoperatively. This immunosuppression was mainly due to a decrease of helper-inducer T cells, cytotoxic T cells, natural killer cells, and interleukin-2 receptor-positive cells, as well as an increase of suppressor T cells. In addition, hypersecretion of cortisol and overproduction of immunosuppressive acidic protein were observed.

CONCLUSIONS

Cellular immunosuppression by surgical stress was mainly due to an increase of lymphocyte subsets that depress cellular immunity coupled with a decrease of the subsets that promote it. Overproduction of cortisol and immunosuppressive acidic protein in response to surgical stress may play an important role in the development of immunosuppression.

Clinical outcomes of EMR for gastric tumors: historical pilot evaluation between endoscopic submucosal dissection and conventional mucosal resection

BACKGROUND

EMR is currently a standard treatment for mucosal gastric tumors. Endoscopic submucosal dissection (ESD) has been developed for en bloc resection.

OBJECTIVE

We evaluated the clinical outcomes of ESD compared with conventional EMR.

DESIGN

Not applicable.

SETTING

A historical control study was performed between EMR and ESD.

PATIENTS

EMR of 245 gastric tumors was performed in 229 patients. Lesions were divided into two groups. Conventional EMR was performed in group A from February 1999 to June 2001, and ESD was performed in group B from July 2001 to March 2004. Group B was divided into subgroups: subgroup B-1 underwent ESD from July 2001 to March 2003 and subgroup B-2 from April 2003 to March 2004.

INTERVENTIONS

All lesions were resected with conventional EMR or with ESD.

MAIN OUTCOME MEASUREMENTS

En bloc resection rate, rate in completeness of resection, required time, remnant ratio, and complications were evaluated.

RESULTS

With regard to lesions >10 mm in size, the en bloc resection rate and the rate in completeness of resection of group B was significantly higher than that of group A (p < 0.01). Although the required time was longer in group B than A (p < 0.01), it was shorter in subgroup B-2 compared with B-1 (p < 0.05) with lesions < or =10 mm in size. The remnant ratio and perforation rate were not different between groups.

LIMITATIONS

Not applicable.

CONCLUSIONS

The en bloc resection rate was better with ESD than with conventional EMR. The required time was longer in ESD, but this disadvantage might be improved with experience.

Bell pepper fruit fatty acid hydroperoxide lyase is a cytochrome P450 (CYP74B)

Fatty acid hydroperoxide lyases cleave a C-C bond adjacent to a hydroperoxide group in lipoxygenase derived lipid hydroperoxides to form short-chain aldehydes and oxo-acids. Previously, we showed that fatty acid hydroperoxide lyase from bell pepper fruits is a heme protein whose spectrophotometric properties greatly resemble a cytochrome P450. In order to ascertain the relationship of it to the P450 gene family, we have cloned cDNA encoding fatty acid hydroperoxide lyase from immature bell pepper fruits. The cDNA encodes 480 amino acids, and shares homology with P450s mostly at the C terminus. The heme binding cysteine is recognizable at position 441. The most closely related P450 is allene oxide synthase (CYP74A), with which it has 40% identity. It qualifies the lyase as a member of a new P450 subfamily, CYP74B. From this finding, the enzyme is thought to be a novel member of P450 specialized for the metabolism of lipid peroxides.

Fatty acid 9- and 13-hydroperoxide lyases from cucumber

Fatty acid hydroperoxide lyase (HPL) is a novel P-450 enzyme that cleaves fatty acid hydroperoxides to form short-chain aldehydes and oxo-acids. In cucumber seedlings, the activities of both fatty acid 9HPL and 13HPL could be detected. High 9HPL activity was especially evident in hypocotyls. Using a polymerase chain reaction-based cloning strategy, we isolated two HPL-related cDNAs from cucumber hypocotyls. One of them, C17, had a frameshift and it was apparently expressed from a pseudogene. After repairing the frameshift, the cDNA was successfully expressed in Escherichia coli as an active HPL with specificity for 13-hydroperoxides. The other clone, C15, showed higher sequence similarity to allene oxide synthase (AOS). This cDNA was also expressed in E. coli, and the recombinant enzyme was shown to act both on 9- and 13-hydroperoxides, with a preference for the former. By extensive product analyses, it was determined that the recombinant C15 enzyme has only HPL activity and no AOS activity, in spite of its higher sequence similarity to AOS.

Impacts of excision repair cross-complementing gene 1 (ERCC1), dihydropyrimidine dehydrogenase, and epidermal growth factor receptor on the outcomes of patients with advanced gastric cancer

Using laser-captured microdissection and a real-time RT-PCR assay, we quantitatively evaluated mRNA levels of the following biomarkers in paraffin-embedded gastric cancer (GC) specimens obtained by surgical resection or biopsy: excision repair cross-complementing gene 1 (ERCC1), dihydropyrimidine dehydrogenase (DPD), methylenetetrahydrofolate reductase (MTHFR), epidermal growth factor receptor (EGFR), and five other biomarkers related to anticancer drug sensitivity. The study group comprised 140 patients who received first-line chemotherapy for advanced GC. All cancer specimens were obtained before chemotherapy. In patients who received first-line S-1 monotherapy (69 patients), low MTHFR expression correlated with a higher response rate (low: 44.9% vs high: 6.3%; P=0.006). In patients given first-line cisplatin-based regimens (combined with S-1 or irinotecan) (43 patients), low ERCC1 correlated with a higher response rate (low: 55.6% vs high: 18.8%; P=0.008). Multivariate survival analysis of all patients demonstrated that high ERCC1 (hazard ratio (HR): 2.38 (95% CI: 1.55-3.67)), high DPD (HR: 2.04 (1.37-3.02)), low EGFR (HR: 0.34 (0.20-0.56)), and an elevated serum alkaline phosphatase level (HR: 1.00 (1.001-1.002)) were significant predictors of poor survival. Our results suggest that these biomarkers are useful predictors of clinical outcomes in patients with advanced GC.

An analysis of sit-to-stand movements

We analyzed the movements involved in rising from a knee-high chair in 12 healthy men weighing within +/- 10% of standard body weight. A regular series of transition points was observed in the angles of the hip, knee, and ankle joints throughout the sit-to-stand movement, which was classified into six stages. As the duration of sit-to-stand movements increased, the duration of Stage 2 decreased, whereas Stage 3 grew longer. The durations of stages 4 and 5 remained constant. We also calculated the minimum unilateral hip and knee extension torque per weight in kilograms required for natural sit-to-stand movements, or N-Stand (1.7-2.3 seconds), and found that minimum hip extension torque was 0.7Nm and minimum knee extension torque was 0.9Nm. The minimum hip and knee extension torque required for N-Stand corresponds to a mean 27% and 30%, respectively, of the actual maximum hip and knee extension torque.

Clinical evaluation of endoscopic injection sclerotherapy using n-butyl-2-cyanoacrylate for gastric variceal bleeding

BACKGROUND

Emergency endoscopic injection sclerotherapy (EIS) has been applied to the initial treatment of gastric variceal bleeding and various methods have been attempted.

METHODS

Emergency EIS was performed on 38 patients with gastric variceal bleeding using either the ethanolamine oleate (EO) method or n-butyl-2-cyanoacrylate (Histoacryl) method and the outcome was compared.

RESULTS

Complete haemostasis was defined as continuous haemostasis lasting for 14 days or more. Complete haemostasis was achieved in 52.4% of patients in the EO method versus 100% of those treated with the Histoacryl method, a significant difference, suggesting that the Histoacryl method was superior for achieving haemostasis in an emergency. The cumulative non-bleeding rate was also significantly higher in patients treated with Histoacryl, indicating the durability of haemostasis. There were no serious complications in patients who received either method of sclerotherapy. Post-EIS surgery was required in 42.8% of patients treated with EO, while no surgery was required in those treated with Histoacryl, supporting the greater haemostatic effect of Histoacryl. Although there was no significant difference in the cumulative survival rates of patients treated by these two methods, death from haemorrhage was avoided by using Histoacryl.

CONCLUSIONS

Based on these results, the Histoacryl method is thought to be the initial treatment of choice for gastric variceal bleeding, because it achieved superior haemostasis compared with EO and death by haemorrhage was avoided.

Lifting of lesions during endoscopic mucosal resection (EMR) of early colorectal cancer: implications for the assessment of resectability

BACKGROUND AND STUDY AIMS

This study assessed the indications for and limitations of endoscopic mucosal resection (EMR) for early colorectal cancer, focusing on the way in which the lesion lifts after submucosal injection.

PATIENTS AND METHODS

The study included 94 patients with early colorectal cancer who received EMR treatment. The lifting of the lesion after submucosal injection was analyzed (classified as completely lifted/soft; completely lifted/hard; incompletely lifted; and non-lifted) along with the endoscopic findings, pathological findings, and clinical course.

RESULTS

Almost all completely lifted/soft lesions were mucosal cancers. Some of the completely lifted/hard lesions were staged as sm2. The incompletely lifted lesions included stages sm1 to sm3. Non-lifting lesions were almost always deeper than sm3. The lifting condition was significantly associated with the depth of invasion, and the lesion type was related to the extent of lifting but not to tumor size or recurrent disease. Recurrent disease was noted in three patients who underwent piecemeal EMR.

CONCLUSIONS

The indication for EMR is easily assessed on the basis of the lifting characteristics of the tumor after submucosal injection, which was found to be significantly related to the depth of invasion. The factor limiting the indication for EMR is not the size of a tumor, but its lifting condition.

Relationship between the morphological and biological characteristics of intraductal components accompanying invasive ductal breast carcinoma and patient age

We divided 324 cases with invasive ductal breast carcinoma into three age groups, and investigated the differences in proliferative activity and extension of the intraductal components among the age cohorts. Proliferative activity was expressed as the number of MIB1-positive nuclei per 1000 cancer cells in the intraductal components (MLI), and the intraductal component extension farthest from the invasive focus was defined as the maximum distance of ductal spread (MXDS). Moreover, analyses were conducted for three grade types, classified according to the classification system of ductal carcinoma in situ. The under-40 age group had significantly higher MXDS values than the other two age groups (p = 0.0280), and this trend was more marked in those with the non-high grade without necrosis type (p = 0.0045). The under-40 age group had higher MLIs, but the differences did not reach statistical significance (p = 0.0793). In regard to those with the high grade type, the under-40 age group had significantly higher MLIs than the other two age groups (p = 0.0269), and this trend was not significant in the cases with any other grade types. Associations between the age group and the margin status of the lumpectomy specimens were investigated in the 143 cases in which breast conserving surgery was tried. The under-40s had a significantly higher margin-positive rate in their lumpectomy specimens than the other two age groups (= 0.0362), and this trend was also seen in the groups with the non-high grade without necrosis type (p = 0.0256). These results confirm the importance of considering patient age when designing surgical procedures for breast conserving therapy.

Fatty acid hydroperoxide lyase is a heme protein

Fatty acid hydroperoxide lyase (HPO lyase) is an enzyme that cleaves hydroperoxides of polyunsaturated fatty acids to form short chain aldehydes and omega-oxoacids. Spectrophotometric analyses of HPO lyase highly purified from green bell pepper fruits indicate that it is a heme protein. The heme species was revealed to be heme b (protoheme IX) from the absorption spectrum of the pyridine hemochromogen. Although the spectrum highly resembles that of a plant cytochrome P450, allene oxide synthase from flaxseed, CO treatment of the enzyme caused no appearance of a peak at 450 nm, which is an essential diagnostic feature of a cytochrome P450. Internal amino acid sequences determined with peptide fragments obtained from the lyase showed no homology with any reported sequences.

Fatty acid hydroperoxide lyase in tomato fruits: cloning and properties of a recombinant enzyme expressed in Escherichia coli

Fatty acid hydroperoxide lyase (HPL) is a member of a novel subfamily of cytochrome P450 and catalyzes a cleavage reaction of fatty acid hydroperoxides to form short-chain aldehydes and oxo-acids. A cDNA encoding tomato fruit HPL (LeHPL) was obtained. An active LeHPL was expressed in E. coli and purified. It showed highest activity against the 13-hydroperoxide of linolenic acid, followed by that of linoleic acid. 9-Hydroperoxides were poor substrates. The absorption spectrum of the purified LeHPL in the native form was similar to that of most P450s although a CO-adduct having a lambda max at 450 nm could not be obtained. LeHPL activity is reversibly inhibited by nordihydroguaiaretic acid, while salicylic acid irreversibly inhibited it. LeHPL is kinetically inactivated by fatty acid hydroperoxides, especially 9-hydroperoxides. The inactivation is prevented by inhibitors of LeHPL. Thus, HPL catalytic activity is thought to be essential to its inactivation. During the inactivation, an abolition of the Soret band was evident, indicating that inactivation is caused mainly by degradation of the prosthetic heme in LeHPL.

Th2-like response and antitumor effect of anti-interleukin-4 mAb in mice bearing renal cell carcinoma

Tumor regression in experimental systems has been linked to the activities of Th1 cells. It is, therefore, conceivable that Th2 cells interrupt the expression of tumor immunity since interleukin-4 (IL-4) and IL-10 inhibit the generation of Th1 from precursors and modulate the competence of antigen-presenting cells to activate this lymphocyte subpopulation. Naive murine renal cell carcinoma (renca) cells (1 x 10(5)) were implanted into the subcapsule of the left kidney of Balb/c and Balb/c nude mice at 6-8 weeks of age. After 14 days, Th2 cytokine (IL-4 and IL-10) mRNAs as well as transforming growth factor beta1 mRNA, assessed by reverse transcriptase/polymerase chain reaction were upregulated in the spleen of hosts upon naive renca tumor acceptance, while Th1 cytokine (IL-2 and interferon gamma) mRNAs were almost undetectable. In the renca tumor, IL-10 mRNA was detected but IL-2, interferon gamma, and IL-4 were not. Intraperitoneal administration of anti-(mouse IL-4) mAb (11B11) reduced the renca tumor size (P = 0.018) and prolonged host survival (P = 0.03), but did not reduce the acceptance rate of the tumor (P = 0.18). However, prior depletion of CD4+ or CD8+ cells with monoclonal antibodies abrogated the antitumor effects of anti-IL-4 mAb. In addition, the significant antitumor effect of anti-IL-4 mAb was not observed in Balb/c nude hosts. Renca cells were transfected with the mammalian expression vector pCAGGS containing murine IL-4 cDNA or vector alone, then stable IL-4 transfectants (RencaL or RencaH, low- or high-IL-4-producing respectively) and control renca cells (RencaC) were obtained. RencaL cells, RencaH cells, or RencaC cells (1 x 10(5) each) were implanted into the subcapsule of the left kidney of Balb/c, Balb/c nude, and allogenic C3H/HeJ mice, then tumor formation was evaluated 14 days later. When RencaH cells were innoculated into syngeneic Balb/c hosts, tumor volume was marginally suppressed (P = 0.03) and tumors tended to be rejected (P = 0.06) compared with RencaC cells. However, those effects were not observed in Balb/c nude mice. RencaC, RencaL, and RencaH cells were not accepted by allogeneic C3H mice with or without FK506 administration or donor-specific transfusion. The administration of anti-(mouse IL-4) mAb to Balb/c mice significantly suppressed renca tumor growth by a CD4+ and CD8+ T-cell-dependent mechanism. By contrast, relatively high levels of IL-4 production by renca cells and T cells seemed to be required to induce the rejection and growth suppression of IL-4-producing renca cells in syngeneic hosts.

Odor-structure relationships in n-hexenols and n-hexenals

The relationships between the chemical structures and the odor characteristics were examined on a series of highly purified n-hexenols and n-hexenals-(14 isomers). The C6-enals and the corresponding alcohols resembled in odor characteristics each other. However, the odor strength of the aldehydes was 100-1000 times higher than those of the alcohols. In the principal components analysis, the position of carbon-carbon double-bond in the C6-compounds was closely related to the scores of the first principal component, whereas the functional groups, hydroxy and formyl groups, were related to those of the second principal component except for (Z)-3-hexenol.

Effect of Bcl-2 overexpression in human prostate cancer cells in vitro and in vivo

BACKGROUND

Cancer cells often develop mechanisms to resist apoptosis and the extent of such anti-apoptotic ability has been shown to parallel tumor progression in various malignancies. Among various molecules implicated in regulating apoptosis pathway, bcl-2 and its family members are best characterized.

METHODS

To investigate the effect of bcl-2-mediated anti-apoptotic ability on tumor growth and progression in prostate cancer, a cell line overexpressing bcl-2 (LNCaP/bcl-2) was established by genetically engineering a prostate cancer cell line LNCaP. Tumor growth of LNCaP/bcl-2 was compared with the parental cell line in vitro and in vivo.

RESULTS

LNCaP/bcl-2 cells show resistance to apoptosis caused by nutrient deprivation and did not arrest when cultured in serum-free or androgen-free medium, while parental LNCaP cells or LNCaP cells transfected with the vector only (LNCaP/control) underwent extensive apoptosis on nutrient deprivation and sustained growth suppression in serum-free or androgen-free medium. When injected subcutaneously into nude mice, tumors deriving from LNCaP/bcl-2 cells grew faster compared with LNCaP/control for about 3 weeks (P = 0.02), but this effect was not evident after 5 weeks. Upon castration, the control tumors regressed but LNCaP/bcl-2-derived tumors showed resistance, as was previously reported.

CONCLUSIONS

These data confirm the notion that anti-apoptotic function of bcl-2 is oncogenic and confers resistance to androgen deprivation and also indicate that it may also play a critical role in earlier stages of tumorigenesis.

High proportion of missense mutations of the BRCA1 and BRCA2 genes in Japanese breast cancer families

Mutations in either of two recently identified genes, BRCA1 and BRCA2, are thought to be responsible for approximately two-thirds of all cases of autosomal-dominantly inherited breast cancer. To examine the nature and frequency of BRCA1 and BRCA2 mutations in Japanese families exhibiting a high incidence of breast cancer, we screened 78 unrelated families in this category for mutations of these two genes. Examining the entire coding sequences as well as exon-intron boundaries of both genes by polymerase chain reaction (PCR) single-strand conformation polymorphism (SSCP) and multiplex-SSCP analysis, we identified possible disease-causing alterations in BRCA1 among affected members of 15 families and in BRCA2 in another 14 families. In 15 of those 29 families, the affected individuals carried missense mutations, although most germline mutations reported worldwide have been deletions or nonsense mutations. Our results, indicating that missense mutations of BRCA1 and BRCA2 tend to predominate over frameshifts or nonsense mutations in Japanese breast cancer families, will contribute significantly to an understanding of mammary tumorigenesis in Japan, and will be of vital importance for future genetic testing.

Electron spin resonance studies on the lipoxygenase reaction by spin trapping and spin labelling methods

The rate of oxygenation and that of trapping linoleic acid free radicals in the lipoxygenase [EC 1.13.11.12] reaction were measured in the presence of linoleic acid, oxygen, and nitrosobenzene at various concentrations, with a Clark oxygen electrode and ESR spectroscopy. The results were interpreted under the assumption that the free radical of linoleic acid, an intermediate of the lipoxygenase reaction, reacts competitively with oxygen or nitrosobenzene. The oxidation of the iron in the active site of lipoxygenase caused by the spin label reagent, 2-(10-carboxydecyl)-2-hexyl-4,4-dimethyl-3-oxazolidinyloxyl, was also observed by ESR- and fluorescence-spectroscopy.

Cucumber cotyledon lipoxygenase during postgerminative growth. Its expression and action on lipid bodies

In cucumber (Cucumis sativus), high lipoxygenase-1 (LOX-1) activity has been detected in the soluble fraction prepared from cotyledons of germinating seeds, and the involvement of this enzyme in lipid turnover has been suggested (K. Matsui, M. Irie, T. Kajiwara, A. Hatanaka [1992] Plant Sci 85: 23-32; I. Fuessner, C. Wasternack, H. Kindl, H. Kühn [1995] Proc Natl Acad Sci USA 92: 11849-11853). In this study we have investigated the expression of the gene lox-1, corresponding to the LOX-1 enzyme. LOX-1 expression is highly coordinated with that of a typical glyoxysomal enzyme, isocitrate lyase, during the postgerminative stage of cotyledon development. In contrast, although icl transcripts accumulated in tissue during in vitro senescence, no accumulation of lox-1 mRNA could be observed, suggesting that lox-1 plays a specialized role in fat mobilization. LOX-1 is also known to be a major lipid body protein. The partial peptide sequences of purified LOX-1 and lipid body LOX-1 entirely coincided with that deduced from the lox-1 cDNA sequence. The data strongly suggest that LOX-1 and lipid body LOX-1 are derived from a single gene and that LOX-1 can exist both in the cytosol and on the lipid bodies. We constructed an in vitro oxygenation system to address the mechanism of this dual localization and to investigate the action of LOX-1 on lipids in the lipid bodies. LOX-1 cannot act on the lipids in intact lipid bodies, although degradation of lipid body proteins, either during seedling growth or by treatment with trypsin, allows lipid bodies to become susceptible to LOX-1. We discuss the role of LOX-1 in fat mobilization and its mechanism of action.

Exocrine and endocrine stomach after gastrobulbar preserving pancreatoduodenectomy

Exocrine and endocrine stomach was studied serially in 13 patients who had gastrobulbar preserving pancreatoduodenectomy (GPPD). In most of them, acid output temporarily increased just after operation but recovered. Gastrin response level decreased transiently but returned to the preoperative level. A negative correlation was observed between the acid and gastrin levels, which suggests that the negative feedback mechanism between parietal cells and G cells was maintained. Acid and gastrin levels in GPPD were higher than those in conventional pancreatoduodenectomy (cPD) but not remarkably different from those of the controls. No peptic ulcer was detected after the operation. These findings indicated that GPPD poses little problem concerning offensive factors. Postoperative ulcer formation is considered to be prevented by the authors' procedure, which is devised to best preserve defensive mechanisms so that duodenectomy is minimized and the gastrointestinal continuity is reconstructed physiologically from mouth to anus by end-to-end duodenoduodenestomy, end-to-side pancreatojejunostomy, and end-to-side choledochojejunostomy.

Molecular cloning and expression of Arabidopsis fatty acid hydroperoxide lyase

Fatty acid hydroperoxide lyase (HPOL), an enzyme of the octadecanoid pathway that forms carbon-6 aldehydes such as n-hexanal or (Z)-3-hexenal, was cloned from Arabidopsis thaliana as a full-length cDNA. The HPOL activity obtained by expressing the cDNA in Escherichia coli formed n-hexanal from linoleic acid 13-hydroperoxide, whereas linoleic acid 9-hydroperoxide was not a substrate for the enzyme. The HPOL mRNA is expressed at low level in leaves; however, its accumulation can be found in the inflorescence. Wounding or methyl jasmonate treatments increase the mRNA level in leaves. These results indicate that the HPOL gene is up-regulated in leaves in response to wounding and that the enzyme may be an active component of the octadecanoid defense response.