Characterization and complementation of a Pichia stipitis mutant unable to grow on D-xylose or L-arabinose

Pichia stipitis CBS 6054 will grow on D-xylose, D-arabinose, and L-arabinose. D-Xylose and L-arabinose are abundant in seed hulls of maize, and their utilization is important in processing grain residues. To elucidate the degradation pathway for L-arabinose, we obtained a mutant, FPL-MY30, that was unable to grow on D-xylose and L-arabinose but that could grow on D-arabinitol. Activity assays of oxidoreductase and pentulokinase enzymes involved in D-xylose, D-arabinose, and L-arabinose pathways indicated that FPL-MY30 is deficient in D-xylitol dehydrogenase (D-XDH), D- and L-arabinitol dehydrogenases, and D-ribitol dehydrogenase. Transforming FPL-MY30 with a gene for xylitol dehydrogenase (PsXYL2), which was cloned from CBS 6054 (GenBank AF127801), restored the D-XDH activity and the capacity for FPL-MY30 to grow on L-arabinose. This suggested that FPL-MY30 is critically deficient in XYL2 and that the D-xylose and L-arabinose metabolic pathways have xylitol as a common intermediate. The capacity for FPL-MY30 to grow on D-arabinitol could proceed through D-ribulose.

In vitro antiinflammatory effects of neolignan woorenosides from the rhizomes of Coptis japonica

Five dihydrobenzofuran neolignans, woorenosides I (1), II (2), III (3), IV (4), and V (5), isolated from Coptis japonica (Ranunculaceae), suppressed tumor necrosis factor (TNF)-alpha and nitric oxide (NuOmicron) production, as well as lymphocyte proliferation triggered by inflammatory signals such as various mitogens, in a dose-dependent manner. The results indicate that the woorenosides strongly inhibit the mitogenic response by activated macrophage and lymphocytes and suggest that these compounds may participate in regulating inflammatory processes.

Hormonal regulation of radioiodide uptake activity and Na+/I- symporter expression in mammary glands

The observation that radioiodide uptake (RAIU) activity, mediated by the Na+/I- symporter (NIS), is significantly increased in lactating breast suggests that RAIU and NIS expression in mammary gland are modulated by hormones involved in active lactation. We showed that both the NIS expression level and RAIU in rat mammary gland are maximal during active lactation compared to those in the mammary glands of virgin and pregnant rats as well as the involuting mammary gland. In the lactating mammary gland, NIS is clustered on the basolateral membrane of alveolar cells as a lesser glycosylated form than NIS in thyroid. The RAIU of lactating mammary gland was partially inhibited by treatment with a selective oxytocin antagonist or bromocriptine, an inhibitor of PRL release. These findings suggest that RAIU and NIS expression in mammary gland are at least in part modulated by oxytocin and PRL. Indeed, we showed that NIS messenger ribonucleic acid level was increased in a dose-dependent manner by oxytocin and PRL in histocultured human breast tumors.

Synthesis and structure-activity relationships of novel compounds for the inhibition of TNF-alpha production

This study describes the synthesis, in vitro evaluation and molecular modeling study of novel compounds for the inhibition of TNF-alpha production. Among these compounds, 2-[3-(cyclopentyloxy)-4-methoxyphenyl]-1-isoindolinone (9) was selected as a lead compound and its pyridine derivative 10 was more potent in activity and safer than rolipram.

Pharmacokinetic/pharmacodynamic evaluation of a novel potassium channel opener, SKP-450, in healthy volunteers

To evaluate the pharmacokinetic/pharmacodynamic characteristics of SKP-450, a novel K+ channel opener, a single blind, randomized, placebo-controlled, dose-rising, parallel-group study was conducted in 28 healthy volunteers. The volunteers were randomly allocated to dosage groups of 50 micrograms, 100 micrograms, 200 micrograms, and 300 micrograms. Single doses of SKP-450 were administered orally, after overnight fasting, and serial blood sampling and pharmacodynamic measurements were performed up to 48 hours after the drug was administered. The 200 micrograms group was further studied for food interactions in a crossover fashion. Drug concentrations in plasma were determined by HPLC. Hemodynamic changes after drug administration were evaluated by serial measurements of blood pressure (BP), pulse rate (PR), cardiac index (CI), and total peripheral resistance (TPR), using computerized impedance cardiography. Changes in plasma renin activity (PRA) and aldosterone concentrations (PAC) were determined 4 and 24 hours after drug administration. Both SKP-450 and SKP-818, an active metabolite, showed linear pharmacokinetic characteristics, and food intake did not significantly affect the pharmacokinetic characteristics of either compound. Dose-related pharmacological effects were obvious for both the 200 micrograms and 300 micrograms groups. Hemodynamic parameters related to vasodilation and reflex tachycardia, such as maximum changes in diastolic BP, PR, CI, and TPR, showed significant dose-dependent changes. The area under the time-effect curve (AUEC) of the parameters also showed a similar dose-dependent pattern. The PRA and PAC exhibited significant changes 4 hours after drug administration in the 300 micrograms group. Adverse effects, such as headaches, were more frequently observed at the higher dose levels. SKP-450 was generally well tolerated by these normotensive subjects. The antihypertensive efficacy of SKP-450 needs to be evaluated in hypertensive patients after multiple dosing.

In vitro anti-inflammatory effects of cynaropicrin, a sesquiterpene lactone, from Saussurea lappa

We investigated in vitro anti-inflammatory effects of cynaropicrin, a sesquiterpene lactone from Saussurea lappa, on tumor necrosis factor (TNF)-alpha and nitric oxide (NO) release, and lymphocyte proliferation. Cynaropicrin strongly inhibited TNF-alpha release from lipopolysaccharide-stimulated murine macrophage, RAW264.7 cells, and differentiated human macrophage, U937 cells, proved to produce notable amount of TNF-alpha. It also potently attenuated the accumulation of NO released from lipopolysaccharide- and interferon-gamma-stimulated RAW264.7 cells in a dose-dependent manner. In addition, the immunosuppressive effects of the compound on lymphocyte proliferation in response to mitogenic stimuli were examined. Cynaropicrin also dose-dependently suppressed the proliferation of lymphocytes from splenocytes and interleukin-2-sensitive cytotoxic T lymphocyte, CTLL-2 cells, stimulated by lipopolysaccharide, concanavalin A, phytohemagglutinin and interleukin-2. However, treatment with sulphydryl compound, L-cysteine, abrogated all these inhibitory effects. These results suggest that cynaropicrin may participate in the inflammatory response by inhibiting the production of inflammatory mediators and the proliferation of lymphocytes and its inhibitory effect is mediated through conjugation with sulphydryl groups of target protein(s).

Inhibitor of tumor necrosis factor-alpha production in lipopolysaccharide-stimulated RAW264.7 cells from Amorpha fruticosa

Certain flavonoids were reported to show an immunoregulatory activity against lymphocyte proliferation and cytokine production. In the course of a search for tumor necrosis factor (TNF)-alpha inhibitory compounds from natural plants, we also isolated a prenylfavanone type of flavonoid, amoradicin, from the extract of Amorpha fruticosa by activity-guided fractionation. This compound significantly inhibited TNF-alpha production in lipopolysaccharide (LPS)-stimulated RAW264.7 cells with an IC(50) value of 28.5 microM. The activity was comparable or higher than those of standard flavonoid compounds, genistein and silybin with IC(50) of 24.9 and 140.3 microM, respectively.

Expression and activity of human Na+/I- symporter in human glioma cells by adenovirus-mediated gene delivery

Radioiodide concentrating activity in the thyroid, mediated by human Na+/I- symporter (hNIS), provides a mechanism for effective radioiodide treatment for patients who have invasive, recurrent, and metastatic thyroid cancers after total thyroidectomy. In an attempt to develop hNIS gene transfer for radioiodide therapy for patients with brain tumors, we have constructed recombinant adenoviruses, rAd-CMV-hNIS9 and rAd-CMV-FLhNIS, to express exogenous hNIS in U1240 and U1240Tag human glioma cells. U1240Tag differs from U1240 glioma cells in that it expresses the SV40 large T antigen oncoprotein. In both U1240 and U1240Tag cells, radioiodide uptake (RAIU) activity in the cells infected with rAd-CMV-hNIS9 or rAd-CMV-FLhNIS increases as the adenoviral MOI increases. The protein expression profile of hNIS in infected cells is generally in agreement with their RAIU activity profile. Although the expressed hNIS9 protein appeared to have a shorter half-life than FLhNIS, hNIS9 expression could be maintained by multiple infections in these cells. In addition, we show that hNIS can be expressed and function in a xenografted human glioma by intratumoral injection of rAd-CMV-hNIS9.

Peripheral hypoechoic lesions of the prostate: evaluation with color and power Doppler ultrasound

OBJECTIVE

To assess the usefulness of color and power Doppler ultrasound in predicting the benignity and malignancy of the peripheral hypoechoic lesion of the prostate.

METHODS

Thirty-nine patients who had peripheral hypoechoic lesions on transrectal ultrasound were evaluated with color and power Doppler ultrasound followed by lesion-specific transrectal ultrasound-guided biopsies. The interpretation of color and power Doppler ultrasound was not performed separately and flow signals were categorized using a combination of the two modalities. The amount of flow signals within the lesion was evaluated and categorized into three groups: increased/equal/decreased flow compared to surrounding normal tissue on ultrasound. Doppler spectra could be obtained from the lesions in 23 patients. The amount of flow signals and resistive indexes of the spectra of the lesions were compared with those of surrounding normal tissue using the Mann-Whithney U test.

RESULTS

Transrectal ultrasound-guided biopsy of the hypoechoic lesions revealed prostate cancer in 20 patients and benign prostatic diseases in 19. Flow signals within the lesions were of increased/equal/decreased flow compared to surrounding normal tissue in 16/2/2 in the prostate cancer group and 3/9/7 in the benign disease group, respectively. The difference was statistically significant (p = 0.0003). Resistive indexes of the lesion were 0.58-1.0 (mean 0.75) in the prostate cancer group and 0.57-1.0 (mean 0.80) in the benign disease group, and there was no significant difference between the two groups (p = 0.82). If we consider an increased flow signal within a peripheral hypoechoic lesion as a sign of prostate cancer, color power Doppler ultrasound has a sensitivity of 80%, a specificity of 84%, and an accuracy of 82%.

CONCLUSION

Evaluation of peripheral hypoechoic lesions of the prostate with color and power Doppler may enhance the diagnostic capability of transrectal ultrasound.

Collision tumors of the ovary associated with teratoma: clues to the correct preoperative diagnosis

PURPOSE

Collision tumors represent a coexistence of two adjacent but histologically distinct tumors without histologic admixture in an organ. The purpose of this study was to describe the imaging findings of collision tumors of the ovary associated with teratoma and to look for clues that might lead to the correct preoperative diagnosis.

METHOD

Seven pathologically proven cases of collision tumor of the ovary associated with teratoma were retrospectively reviewed. Ovarian teratomas were coexistent with mucinous cystadenoma (n = 4), borderline mucinous tumor (n = 1), mucinous cystadenocarcinoma (n = 1), and dysgerminoma (n = 1). US (n = 5), CT (n = 3), and/or MRI (n = 4) findings were evaluated.

RESULTS

In addition to the typical findings of teratoma, the mass contained a multiloculated cystic portion filled with nonfatty fluid, suggesting the coexistent epithelial tumor in five cases. In one case, the mass contained a large solid component, suggesting the possibility of collision tumor. In the remaining one case, coexistent small mucinous cystadenoma could not be identified.

CONCLUSION

Preoperative imaging for ovarian teratoma revealed a collision tumor in six of seven cases. The possibility of a collision tumor should be considered when an ovarian teratoma has imaging findings that cannot be explained solely by an ovarian teratoma.

Immunomodulatory effect of arctigenin, a lignan compound, on tumour necrosis factor-alpha and nitric oxide production, and lymphocyte proliferation

We have investigated the immunomodulatory effects of arctigenin, a dibenzyl butyrolactone lignan compound, on tumour necrosis factor (TNF)-alpha and nitric oxide (NO) production, and lymphocyte proliferation. Arctigenin inhibited strongly TNF-alpha production by lipopolysaccharide-stimulated murine macrophage RAW264.7 and differentiated human macrophage U937 with IC50 values of 5.0 and 3.9 microM, respectively, without displaying cytotoxicity. The TNF-alpha inhibitory effect of arctigenin in lipopolysaccharide-triggered RAW264.7 cells was increased by co-treatment with several known TNF-alpha inhibitors. It also potently attenuated T and B cell proliferation stimulated by concanavalin A and lipopolysaccharide in a dose-dependent manner with IC50 values of 2.9 and 14.6 microM, respectively. In contrast, the compound showed a different pattern in lipopolysaccharide- and interferon (IFN)-gamma-induced NO production from RAW264.7 cells. Arctigenin inhibited NO release by IFN-gamma signal, whereas it significantly enhanced lipopolysaccharide-triggered NO production in RAW264.7 cells. The results suggested that arctigenin may regulate immune responses in activated macrophages and lymphocytes including TNF-alpha and NO production and lymphocyte proliferation.

Mini-detachable snare ligation for the treatment of esophageal varices

BACKGROUND

We manufactured and studied the usefulness of a newly designed mini-detachable snare in the treatment of esophageal varices. The use of a multiple rubber band ligator, although generally effective and well tolerated, has certain limitations, including high cost, reduced visual field, and inadvertent band release.

METHODS

We performed a prospective randomized controlled trial of the use of mini-detachable snare ligation vs. multiple band ligation in patients with recent or active esophageal variceal bleeding. The outcomes assessed were immediate hemostasis and rates of recurrent bleeding, eradication, and recurrence.

RESULTS

From March 1997 to October 1998, 103 patients were entered into this trial; 46 underwent mini-detachable snare ligations and 57 multiple band ligations. Among patients with active bleeding, hemostasis was achieved in 6 of 7 (86%) in the mini-detachable snare ligation group and 11 of 13 (85%) in multiple band ligation group. Recurrent bleeding after initial treatment occurred in 2 of 46 (5.5%) in the mini-detachable snare ligation group and 3 of 57 (5.3%) in the multiple band ligation group. Esophageal varices were eradicated or reduced to grade I in 4.8 +/- 2.1 and 4.5 +/- 1.9 sessions in the mini-detachable snare ligation group and multiple band ligation group, respectively. The recurrence rate was 5 of 46 (11%) and 6 of 57 (11%) in the mini-detachable snare ligation group and multiple band ligation group during a follow-up period of 6 and 16 months, respectively. No serious complication occurred in either group.

CONCLUSION

The mini-detachable snare is a new device that provides safe and effective treatment for esophageal varices that is comparable to multiple band ligation.

Eudesmin inhibits tumor necrosis factor-alpha production and T cell proliferation

Possible antiinflammatory effects of eudesmin were examined by assessing the effects on tumor necrosis factor (TNF)-alpha production and lymphocyte proliferation as well as cytotoxicity against murine and human macrophages. The compound significantly inhibited TNF-alpha production by lipopolysaccharide (LPS)-stimulated murine macrophage RAW264.7 without displaying cytotoxicity suggesting that eudesmin may inhibit TNF-alpha production without any interference of normal cell function. It also significantly attenuated T cell proliferation stimulated by concanavalin A (Con A) in a dose-dependent manner.

Diversity of core promoter mutations in immune clearance phase of chronic HBV infection

BACKGROUND/AIMS

Transcription of HBV (hepatitis B virus) pre-core and pre-genomic mRNAs is controlled by core promoter. Therefore, mutations in the core promoter region might change the activity of liver diseases through an altered transcriptional level of the mRNA. The present study was carried out to determine the diversity of HBV core promoter sequences in chronic HBV carriers.

METHODS

DNA sequences in the core promoter region were determined after cloning the PCR product. Two groups of chronic HBV carriers with HBeAg, including five cases of asymptomatic carriers (ASCs, 21 clones) and eight with chronic hepatitis (CH, 50 clones) were studied.

RESULTS

Mutations in the core promoter were found in three out of the ASCs (11 clones), and in all eight cases in the CH group (48 clones). While mutations at nucleotide 1762 (A-->T) and 1764(G-->A) were not found in ASC, mutations at the same positions were found in all the cases of CH group (40 clones) (P=0.003). Diverse patterns of mutations in the core promoter were observed in each patient in the CH group.

CONCLUSIONS

Further studies are needed to determine whether the diversity of HBV core promoter mutations has clinical significance such as the seroconversion of HBeAg to anti-HBe.

Early cellular abnormalities induced by RET/PTC1 oncogene in thyroid-targeted transgenic mice

The RET/PTC1 oncogene, a rearranged form of the RET proto-oncogene, has been reported to be associated with human papillary thyroid carcinomas. We have shown that targeted expression of RET/PTC1 in the thyroid gland leads to the development of thyroid carcinomas in transgenic mice with histologic and cytologic similarities to human papillary thyroid carcinoma. To further investigate how RET/PTC1 expression contributes to the pathogenesis of papillary thyroid tumor, the time of tumor onset and the early phenotypic consequences of RET/PTC1 expression in thyrocytes were determined. All high copy transgenic mice developed bilateral thyroid tumors as early as 4 days of age. At embryological days 16-18, increased proliferation rate, distorted thyroid follicle formation and reduced radioiodide concentrating activity were identified in transgenic embryos. The reduced radioiodide concentrating activity was attributed to decreased expression of the sodium-iodide symporter. Our study showed that RET/PTC1 not only increased proliferation of thyrocytes, it also altered morphogenesis and differentiation. These findings provide a model for the role of RET/PTC1 in the formation of abnormal follicles with reduced iodide uptake ability observed in human papillary thyroid carcinoma.

Transcriptional control of ADH genes in the xylose-fermenting yeast Pichia stipitis

We studied the expression of the genes encoding group I alcohol dehydrogenases (PsADH1 and PsADH2) in the xylose-fermenting yeast Pichia stipitis CBS 6054. The cells expressed PsADH1 approximately 10 times higher under oxygen-limited conditions than under fully aerobic conditions when cultivated on xylose. Transcripts of PsADH2 were not detectable under either aeration condition. We used a PsADH1::lacZ fusion to monitor PsADH1 expression and found that expression increased as oxygen decreased. The level of PsADH1 transcript was repressed about 10-fold in cells grown in the presence of heme under oxygen-limited conditions. Concomitantly with the induction of PsADH1, PsCYC1 expression was repressed. These results indicate that oxygen availability regulates PsADH1 expression and that regulation may be mediated by heme. The regulation of PsADH2 expression was also examined in other genetic backgrounds. Disruption of PsADH1 dramatically increased PsADH2 expression on nonfermentable carbon sources under fully aerobic conditions, indicating that the expression of PsADH2 is subject to feedback regulation under these conditions.

Effects of interleukin-2 transduction on the human hepatoma cell lines using retroviral vector

Gene therapy, using cytokine gene transduction, aims to increase the antigenicity of tumor cells, and to activate the immune effector cells, and thereby inducing tumor regression. With regards to in vitro sensitivity to peripheral blood monocytes and in vivo tumorigenic activity we compared the differences between parent hepatoma cell lines and interleukin-2 (IL-2) transduced hepatoma cell lines using N2A/IL-2 and LNC/IL-2 retrovirus. IL-2 secretion was 186 pg/10(6) cells/24 h in SK-Hep1 cell line and 147 pg/106 cells/24 h in Hep-3B cell line with N2A/IL-2 retroviral vector and was 55,000 pg/10(6) cells/24 h in Hep-3B cell line with LNC/IL-2 retroviral vector. in vitro sensitivity to peripheral blood monocytes was increased by 163.8-254% in IL-2 transduced hepatoma cell lines (Hep-3B/LNC/IL-2, Hep-G2/LNC/IL-2) compared to those of the parent cell lines. The tumor was formed in 1 of 3 BALB/c mice and all 3 nude mice with the injection of 1x107 cells. Simultaneous injection of 1x10(7) cells of the parent cell line (Hep-3B) into the right flank and IL-2 transduced cell line (Hep-3B/LNC/IL-2) into the left flank of the three BALB/c mice and of 5x10(5) cells for the three nude mice resulted in a complete regression of the IL-2 modified tumor cell line (Hep-3B/LNC/IL-2) in 3 weeks and the parent cell line (Hep-3B) in 5 weeks. After injection of 1x10(7) cells into five other nude mice, the tumor of the IL-2 transduced hepatoma cells (Hep-3B/LNC/IL-2) gradually disappeared, however, the tumor of the parent hepatoma cell line initially decreased and then gradually regrew 20 days later. In conclusion, IL-2 transduced hepatoma cell lines secreting IL-2 became more sensitive to peripheral blood monocytes. IL-2 secretion by LNC/IL-2 retrovirus from the hepatoma cell lines was more prominent compared with that by N2A/IL-2 retrovirus. IL-2 transduction into the hepatoma cells resulted in increased antigenicity to the tumors formed by IL-2 transduced hepatoma cell line and parent cell line, which leads the regression of the tumors. However, the higher the tumor burden, the less efficient tumor regression by IL-2 transduction into the hepatoma cell line in nude mice was observed.

CT findings of isolated small bowel angioedema due to iodinated radiographic contrast medium reaction

We report three cases of small bowel angioedema that showed circumferential wall thickening of the small bowel loops during infusion of iodinated contrast media. Follow-up small bowel series or computed tomography confirmed the normalized small bowel loops. When significant wall thickening of the long segment of the small bowel during infusion of contrast media is seen, radiologists should consider the possibility of isolated small bowel angioedema in spite of its rarity.

Thyroid carcinomas in RET/PTC transgenic mice

The RET/PTC oncogene, a rearranged form of the RET proto-oncogene, has been found to be associated with human papillary thyroid carcinomas. To investigate whether RET/PTC causes papillary thyroid carcinoma, we generated a transgenic mouse model of papillary thyroid carcinoma with targeted expression of RET/PTC1 in the thyroid gland. Thyroid tumors in these RET/PTC1 transgenic mice are characterized by a slow growth rate, thyroid-stimulating hormone (TSH)-responsive tumor progression, and loss of radioiodide-concentrating activity despite continued expression of thyroglobulin (Tg). The time of tumor onset appears to be dependent on the expression level of RET/PTC1 in these transgenic mice. In high-copy RET/PTC1 transgenic mice, cellular abnormalities, including a slightly increased proliferation rate, aberrant follicle formation, and loss of radioiodide-concentrating activity, can be readily identified at embryological day 18. To identify which signaling pathway or pathways perturbed by RET/PTC1 are essential for RET/PTC1 to induce tumor development, we generated transgenic mice carrying a thyroid-targeted RET/PTC1 triple mutant, which contains tyrosine to phenylalanine mutations at tyrosine residues 294, 404, and 451. Initial characterization of the thyroid glands of these RET/PTC1 triple-mutant transgenic mice showed no change in follicular morphology or radioiodide-concentrating activity. This finding suggests that signaling pathways mediated by one or more of these three phosphotyrosine binding sites are essential for RET/PTC1 to induce thyroid tumor development. Finally, in order to investigate whether tumors induced by RET/PTC3 are more aggressive than those tumors induced by RET/PTC1, we also generated thyroid-targeted RET/PTC3 transgenic mice.

Ovarian teratomas appearing as solid masses on ultrasonography

The purposes of this study were to evaluate the prevalence and imaging characteristics of ovarian teratomas that appear as solid masses on ultrasonography and to compare the ultrasonographic imaging features of the tumors with their pathologic findings. The ultrasonographic images of 202 ovarian teratomas were reviewed retrospectively. Solid-appearing masses were selected from among them and were evaluated in terms of internal echotexture, the presence or lack of peripheral hypoechogenicity, posterior sonic attenuation, and tumoral calcification. Seventy-six (37.6%) masses of 202 belonged to the atypical solid-appearing masses on ultrasonography. Of 76 masses, 57 (75.0%) had peripheral hypoechogenicity; 38 masses had well-defined thin hypoechoic rims, whereas 19 had poorly demarcated peripheral hypoechogenicity. Posterior sonic attenuation was evident in 18 (23.7%) masses. The presence of peripheral hypoechogenicity, which is suggestive of the fluid portion of the tumor, might be one of the characteristic findings of solid-appearing ovarian teratomas on ultrasonography.

Effects of interleukin-2 transduction on the human hepatoma cell lines using retroviral vector

Gene therapy, using cytokine gene transduction, aims to increase the antigenicity of tumor cells, and to activate the immune effector cells, and thereby inducing tumor regression. With regards to in vitro sensitivity to peripheral blood monocytes and in vivo tumorigenic activity we compared the differences between parent hepatoma cell lines and interleukin-2 (IL-2) transduced hepatoma cell lines using N2A/IL-2 and LNC/IL-2 retrovirus. IL-2 secretion was 186 pg/10(6) cells/24 h in SK-Hep1 cell line and 147 pg/106 cells/24 h in Hep-3B cell line with N2A/IL-2 retroviral vector and was 55,000 pg/10(6) cells/24 h in Hep-3B cell line with LNC/IL-2 retroviral vector. in vitro sensitivity to peripheral blood monocytes was increased by 163.8-254% in IL-2 transduced hepatoma cell lines (Hep-3B/LNC/IL-2, Hep-G2/LNC/IL-2) compared to those of the parent cell lines. The tumor was formed in 1 of 3 BALB/c mice and all 3 nude mice with the injection of 1x107 cells. Simultaneous injection of 1x10(7) cells of the parent cell line (Hep-3B) into the right flank and IL-2 transduced cell line (Hep-3B/LNC/IL-2) into the left flank of the three BALB/c mice and of 5x10(5) cells for the three nude mice resulted in a complete regression of the IL-2 modified tumor cell line (Hep-3B/LNC/IL-2) in 3 weeks and the parent cell line (Hep-3B) in 5 weeks. After injection of 1x10(7) cells into five other nude mice, the tumor of the IL-2 transduced hepatoma cells (Hep-3B/LNC/IL-2) gradually disappeared, however, the tumor of the parent hepatoma cell line initially decreased and then gradually regrew 20 days later. In conclusion, IL-2 transduced hepatoma cell lines secreting IL-2 became more sensitive to peripheral blood monocytes. IL-2 secretion by LNC/IL-2 retrovirus from the hepatoma cell lines was more prominent compared with that by N2A/IL-2 retrovirus. IL-2 transduction into the hepatoma cells resulted in increased antigenicity to the tumors formed by IL-2 transduced hepatoma cell line and parent cell line, which leads the regression of the tumors. However, the higher the tumor burden, the less efficient tumor regression by IL-2 transduction into the hepatoma cell line in nude mice was observed.

Colonoscopic diagnosis of whipworm infection

Trichuriasis is an intestinal infection found in human beings which is caused by Trichuris trichiura, more commonly known as whipworm because of its whip-like appearance. It is characterized by the invasion of the colonic mucosa by the adult Trichuris and produces minor inflammatory changes at the sites of localization. It is prevalent throughout the world, especially in tropical areas. Its diagnosis is usually made by identification of the typical eggs in the stool; adult whipworm is rarely seen during colonoscopy. Colonoscopy can directly diagnose trichuriasis, confirming the threadlike form of worms with an attenuated end. The worms can be overlooked, particularly if colon preparation is imperfect. Attenuated whip-like ends of whipworms, which are embedded in the colonic mucosa, were removed with biopsy forceps. We report on 5 cases of whipworm infection that were diagnosed on total colonoscopy.

Antimicrobial activity of 4-hydroxybenzoic acid and trans 4-hydroxycinnamic acid isolated and identified from rice hull

Two antimicrobial substances in rice hull were isolated and identified as 4-hydroxybenzoic acid and trans 4-hydroxycinnamic acid by LC-MS, and 1H- and 13C-NMR. An evaluation of 50% inhibition of growth (IC50) revealed that the two substances had different inhibition profiles against various microorganisms. Most of the gram-positive and some gram-negative bacteria were sensitive to trans 4-hydroxycinnamic acid and 4-hydroxybenzoic acid at IC50 concentrations of 100-170 and 160 micrograms/ml, respectively.

Inhibitory effect of sesquiterpene lactones from Saussurea lappa on tumor necrosis factor-alpha production in murine macrophage-like cells

Total methanol extract of Saussurea lappa radix (Compositae) showed potent inhibitory effect on the production of tumor necrosis factor-alpha (TNF-alpha), a proinflammatory cytokine, in murine macrophage-like cell (RAW264.7 cells) in our previous screening studies on 120 Korean medicinal plants. The activity-guided purification of the plant resulted in the isolation of three components. The chemical structures of the components isolated were established by spectroscopic analyses as sesquiterpene lactones [cynaropicrin (1), reynosin (2), and santamarine (3)]. These three compounds inhibited TNF-alpha production in a dose-dependent manner. The molar concentrations of cynaropicrin, reynosin, and santamarine producing 50% inhibition (IC50) of TNF-alpha production were 2.86 micrograms/ml (8.24 microM), 21.7 micrograms/ml (87.4 microM), and 26.2 micrograms/ml (105 microM), respectively. However, treatment with sulphydryl (SH) compounds such as L-cysteine, dithiothreitol, and 2-mercaptoethanol abrogated the inhibitory effect of cynaropicrin on TNF-alpha production. Therefore, we conclude that the principal inhibitory component of Saussurea lappa is cynaropicrin and its inhibitory effect is mediated through conjugation with SH-groups of target proteins.

An immunohistochemical study of Na+/I- symporter in human thyroid tissues and salivary gland tissues

The human Na+/I- symporter (hNIS) is the plasma membrane protein that mediates active iodide uptake into several tissues, such as the thyroid and salivary glands. To study the distribution and cellular localization of the hNIS protein, we have generated a polyclonal antibody that could detect the hNIS protein by immunohistochemical staining on tissue sections. In normal thyroids, hNIS expression is heterogeneous, and it is only detected in sporadic thyrocytes of a given follicle. The hNIS protein was not detected in thyroid carcinomas, yet it was detected in the majority of thyrocytes in Graves' thyroids. In salivary glands, hNIS protein was not detected in acinar cells, but it was detected in ductal cells. The hNIS proteins are clustered in the basal and lateral membranes in cells stained positive for hNIS.

The periodontist and the edentulous area--localised ridge augmentation

The replacement of missing dentition by implant-borne dental restoration has been shown to be a highly predictable treatment method with good long-term prognosis. Subsequently, the use of implant-borne restorations has gradually increased over the use of conventional partial dentures and fixed restorations in recent years. Sufficient bone volume is the most important factor for successful implant-borne restoration, but often an insufficient amount of bone is found at implant sites. A new surgical approach to enlarge the width of alveolar crest was introduced by Buser et al. in 1996. This new approach is based on the principle of guided bone regeneration technique using a barrier membrane with autogenous bone grafts in the form of bone blocks, chips and particles. This promising new surgical technique allows placement of dental implants for implant-borne restorations in partially edentulous patients who were previously not considered to be implant candidates because of insufficient bone at the implant sites.

Compression of large uterine myoma by sacral promontory: MR findings

We present the MR findings of three cases of large uterine myomas that had geographically nonenhancing areas that were compressed by the sacral promontory. These nonenhancing areas on contrast-enhanced T1-weighted images showed no abnormal signal intensity on T2-weighted images. On delayed images following contrast medium administration, the nonenhancing area eventually enhanced homogeneously. There was no evidence of degeneration at pathologic examination. We think that the sacral promontory may compress large myomas with vascular insufficiency, resulting in delayed contrast enhancement of that area.

Krukenberg tumor findings at color and power Doppler US; correlation with findings at CT, MR imaging, and pathology. Case reports

We report on the findings at color and power Doppler US in 2 cases of Krukenberg tumor. Power Doppler US may suggest a Krukenberg tumor when it shows a relatively prominent vascular signal along the wall of well-demarcated intramural cysts in a solid ovarian mass.

Diffuse prostatic lesions: role of color Doppler and power Doppler ultrasonography

The purpose of this study was to assess the role of color Doppler ultrasonography and power Doppler ultrasonography in the identification of diffuse prostatic lesions. Forty male patients underwent gray scale transrectal ultrasonography, color and power Doppler sonography, and transrectal ultrasonographically guided biopsy. Transrectal ultrasonographically guided biopsy revealed cancer in 23 patients and benign lesions in 17 patients. Among the prostatic cancers 82.6% (19 of 23) showed increased flow signals, whereas 23.5% (four of 17) of benign lesions showed increased flow signals on color or power Doppler ultrasonography. If we consider increased flow signal on color or power Doppler sonography as a sign of a prostate cancer in diffuse prostatic lesions, these modalities have a sensitivity of 82.6%, specificity of 76.5%, and positive predictive value of 82.6%. On the basis of our study, we may conclude that color and power Doppler ultrasonography are useful in the identification of diffuse prostatic lesions.

Preliminary results of a new covered biliary metal stent for malignant biliary obstruction

BACKGROUND AND STUDY AIMS

The biliary stents in current use have a tendency to be blocked, so we designed a self-expandable metal stent covered with polyurethane to overcome the risk of tumor ingrowth of uncovered self-expandable metal stents. To evaluate the success and the effectiveness of the new membrane-covered self-expandable metal stent (covered modified Gianturco biliary stent), we studied patients with biliary obstruction caused by biliopancreatic carcinoma.

PATIENTS AND METHODS

We retrospectively evaluated 47 patients with malignant biliary obstruction to receive either a newly developed self-expandable metal stent covered with polyurethane (21 cases) or an uncovered metal stent (Strecker stent or Wallstent, 26 cases) by the endoscopic transpapillary route.

RESULTS

The success rate of stent insertion and drainage effect of stent showed no statistical difference in patients with a new membrane-covered self-expandable metal stent compared with those with an uncovered metal stent (90.4% vs. 88.5%, P > 0.05; and 100% vs. 95.6%, P > 0.05, respectively). The median patency of the stent was slightly prolonged in patients with a membrane-covered self-expandable metal stent, but there was no statistical difference between two groups (267 vs. 233 days, P > 0.05). The rate of early complication related to stent insertion showed no significant difference between the two groups. During the follow-up period, stent occlusion due to tumor ingrowth occurred in two patients (10.5%) in the membrane-covered, self-expandable stent group, compared with six patients (26.1%) in the uncovered metal stent group. The membrane-covered metal stent was removed successfully and a polyethylene stent was reinserted in one patient who had developed tumor overgrowth.

CONCLUSIONS

A new, membrane-covered, self-expandable metal stent has a tendency towards better long-term patency than the uncovered metal stent, and it can effectively prevent tumor ingrowth into the stent. Also it is possible to remove an occluded membrane-covered stent. However, a case-controlled study, including a larger patient number, and long-term follow-up are needed.

Pichia stipitis genes for alcohol dehydrogenase with fermentative and respiratory functions

Two genes coding for isozymes of alcohol dehydrogenase (ADH); designated PsADH1 and PsADH2, have been identified and isolated from Pichia stipitis CBS 6054 genomic DNA by Southern hybridization to Saccharomyces cerevisiae ADH genes, and their physiological roles have been characterized through disruption. The amino acid sequences of the PsADH1 and PsADH2 isozymes are 80.5% identical to one another and are 71.9 and 74.7% identical to the S. cerevisiae ADH1 protein. They also show a high level identity with the group I ADH proteins from Kluyveromyces lactis. The PsADH isozymes are presumably localized in the cytoplasm, as they do not possess the amino-terminal extension of mitochondrion-targeted ADHs. Gene disruption studies suggest that PsADH1 plays a major role in xylose fermentation because PsADH1 disruption results in a lower growth rate and profoundly greater accumulation of xylitol. Disruption of PsADH2 does not significantly affect ethanol production or aerobic growth on ethanol as long as PsADH1 is present. The PsADH1 and PsADH2 isozymes appear to be equivalent in the ability to convert ethanol to acetaldehyde, and either is sufficient to allow cell growth on ethanol. However, disruption of both genes blocks growth on ethanol. P. stipitis strains disrupted in either PsADH1 or PsADH2 still accumulate ethanol, although in different amounts, when grown on xylose under oxygen-limited conditions. The PsADH double disruptant, which is unable to grow on ethanol, still produces ethanol from xylose at about 13% of the rate seen in the parental strain. Thus, deletion of both PsADH1 and PsADH2 blocks ethanol respiration but not production, implying a separate path for fermentation.

Inhibitory effect of lignans from the rhizomes of Coptis japonica var. dissecta on tumor necrosis factor-alpha production in lipopolysaccharide-stimulated RAW264.7 cells

The inhibitory effect of 10 lignan constituents isolated from the rhizomes of Coptis japonica var. dissecta on tumor necrosis factor (TNF)-alpha production in lipopolysaccharide (LPS)-stimulated macrophage cell line (RAW264.7 cells) has been studied. Among them, pinoresinol, woorenoside-V and lariciresinol glycoside showed significant inhibitory activities in the range from 37% to 55% at the concentration of 25 micrograms/ml. The results are first report that the lignans isolated from Coptis japonica inhibit TNF-alpha production, and suggest that the lignan components may partly participate in antiinflammatory and antiallergic effect of Coptis japonica through the inhibition of TNF-alpha production.

Isolation and identification of inhibitory compounds on TNF-alpha production from Magnolia fargesii

Three TNF alpha-inhibitory lignans were isolated from the flower buds of Magnolia fargesii through bioassay-guided isolation. They were identified as eudesmin, magnolin and lirioresinol-B dimethylether on the basis of their spectroscopic data. All three lignans showed inhibitory effects on TNF-alpha production in LPS-stimulated murine macrophage cell line, RAW264.7 and eudesmin showed the strongest activity (IC50 = 51 microM).

Suppression of xenobiotic-metabolizing enzyme expression in rats by acriflavine, a protein kinase C inhibitor. Effects on epoxide hydrolase, glutathione S-transferases, and cytochromes p450

The effects of acriflavine (ACF), a protein kinase C inhibitor, on the expression of hepatic microsomal epoxide hydrolase (mEH), glutathione S-transferases (GSTs), and cytochrome P450 (P450) were assessed in rat hepatic tissue. Northern blot analysis revealed that treatment of rats with thiazole, allyl disulfide (ADS), oltipraz, or clotrimazole at a single dose of 100 mg/kg resulted in 7-18-fold increases in mEH mRNA levels at 24 hr, whereas concomitant ACF treatment (20 mg/kg, im) caused 50-95% inhibition of the chemical-induced increases in hepatic mEH mRNA levels. rGSTA2, rGSTA3, and rGSTM1 mRNA levels were also significantly suppressed at 24 hr in response to a single dose of ACF (20 mg/kg, im). Animals treated with both ACF and ADS showed complete blockage of mEH and GST gene expression as early as 12 hr after treatment. ADS-inducible increases in mEH and rGSTA2 mRNA levels were suppressed at 24 hr after treatment with ACF, in a dose-related manner, with 50% inhibitory dose (ID50) values of 2.0-2.3 mg/kg, whereas glyceraldehyde-3-phosphate dehydrogenase mRNA levels were not altered. Immunoblot analysis revealed that ACF (15 mg/kg/day, im, for 3 days) inhibited induction of mEH or rGSTA2 protein by ADS (100 mg/kg/day, po, for 3 days). The levels of hepatic P450 2B1/2, P450 2C11, and P450 3A1/2 were decreased in rats treated with ACF (15 mg/kg/day, im, for 3 days), whereas P450 1A2 and P450 2E1 expression was not affected. Treatment of rats with ACF in combination with gadolinium chloride, which inhibits mEH and GST expression through calcium channel blocking, shifted the dose-inhibitory response curves for ACF to the left, with 7-15-fold decreases in the ID50 values, indicating that the active site for ACF for suppression of mEH and GST mRNA levels differs from that for gadolinium chloride. Proflavine and safranine O, which are structurally related to ACF, also caused suppression of ADS-induced increases in mRNA levels, in a dose-dependent manner, with ID50 values of 4-9 mg/kg. These results demonstrate that ACF and its related compounds effectively suppress the expression of a battery of hepatic xenobiotic-metabolizing enzymes, including mEH, GSTs, and certain P450 forms.

Half-dose gadolinium-enhanced MR imaging with magnetization transfer technique in brain tumors: comparison with conventional contrast-enhanced MR imaging

OBJECTIVE

The purpose of this study was to determine whether half-dose enhanced MR imaging with magnetization transfer (MT) saturation can replace standard-dose enhanced MR imaging without MT saturation in patients who have brain tumors.

SUBJECTS AND METHODS

Three sets of enhanced T1-weighted MR images were prospectively obtained for each of 25 patients with 32 brain tumors; the first conventional MR images without MT were obtained after administration of standard-dose (0.1-mmol/kg) gadopentetate dimeglumine. Within 1 week, patients underwent administration of one half-dose (0.05 mmol/kg) of the contrast medium, and then two sets of enhanced T1-weighted images were obtained with and then without MT. The degree of contrast enhancement was assessed qualitatively for all 32 tumors and quantitatively for 26 tumors. In the quantitative analysis, we compared mean values for tumor-brain contrast-to-noise ratios in three sets of images.

RESULTS

The visual conspicuity of enhancing lesions in half-dose T1-weighted MR images with MT was comparable with that of standard-dose conventional T1-weighted MR images in 43% of cases including most extraaxial tumors. In approximately 75% of cases, the degree of enhancement of the lesions was similar for half-dose T1-weighted images obtained with and without MT. Overall, mean values for tumor-brain contrast-to-noise ratios were significantly lower in half-dose T1-weighted images with MT than in standard-dose T1-weighted images. Also, mean values for tumor-brain contrast-to-noise ratios were significantly higher in half-dose T1-weighted images with MT than in half-dose T1-weighted images without MT.

CONCLUSION

Because half-dose enhanced MR imaging with MT yields enhancement comparable with that of standard-dose enhanced conventional MR imaging in less than 50% of cases, the former technique would replace the latter in only limited cases such as selected extraaxial tumors.

Retrospective comparison of infusional 5-fluorouracil, doxorubicin, and mitomycin-C (modified FAM) combination chemotherapy versus palliative therapy in treatment of advanced gastric cancer

About one-third of patients with gastric cancer are unresectable at the time of diagnosis. Their median survival is < 6 months, with a grave prognosis. The purpose of this study was to assess the efficacy of a modified FAM (mFAM) regimen in advanced gastric cancer. We retrospectively reviewed the clinical records of 409 advanced gastric cancer patients who had not received curative surgery. Among 409 patients, 202 patients were treated with an mFAM regimen (infusional 5-FU + doxorubocin + mitomycin-C), and 207 patients received no chemotherapy (control group). No differences were found in clinical parameters between the two groups. The 1-year survival rates were 34.1% for the mFAM-treated group and 22.5% for the control group (p = 0.0135). In subset analysis, a higher 1-year survival rate was demonstrated in patients with mFAM and palliative surgery. Of the 154 evaluable patients in the mFAM-treated group, the response rate was 17.5%. In these patients, median response duration was 30 weeks, and progression-free survival was 23 weeks. Overall toxicity of mFAM regimen was relatively tolerable and reversible. In conclusion, FAM combination chemotherapy, which has been used as a standard therapy, prolonged survival after modification of the administration schedule and combination with palliative surgery. A prospective randomized study is warranted to confirm this conclusion from our retrospective study.

Radiological findings in serous surface papillary carcinoma of the ovary. Case reports

Serous surface papillary carcinoma (SSPC) is a malignant tumor originating from the surface epithelium of the ovary, and is characterized by macroscopic normal ovaries accompanied by diffuse peritoneal dissemination. Therefore diagnosis of SSPC cannot usually be made preoperatively. We report on two cases of SSPC in which US, CT, and MR demonstrated nodularities along the surface of the normal-sized ovaries, adjacent organs and pelvic peritoneum in addition to findings of peritoneal seeding. These imaging findings may suggest the correct preoperative diagnosis of SSPC.

Differential induction of hepatic microsomal epoxide hydrolase by alkyl sulphides and alkyl ethers in rat

1. Previous studies have shown that the expression of certain cytochromes P450 and major glutathione S-transferases (GSTs) is differentially modulated by alkyl sulphide treatment. The current study was designed to examine the influence of several alkyl sulphides and alkyl ethers on the induction of hepatic microsomal epoxide hydrolase (mEH) in rat. 2. Northern blot analysis has shown that treatment of rats with allyl disulphide (ADS) or allyl sulphide (AS) (50 mg/kg/day, 7 days) resulted in 5-6-fold increases in mEH mRNA levels, whereas allyl ether failed to stimulate mEH gene expression. Rats treated with propyl disulphide (PDS) or propyl sulphide (PS) exhibited increases in mEH mRNA levels, although the relative increases were less than those produced by ADS or AS. Propyl ether failed to increase hepatic mEH mRNA levels. Immunoblot analyses confirmed that allyl and propyl sulphides induce hepatic mEH protein, with the agents containing allyl moiety being more effective. 3. Treatment of rats with ADS at 100 mg/kg resulted in 9-14-fold increases in mEH mRNA levels at 12 and 24 h post-treatment respectively, whereas AS caused a maximal increase at the 24-h time point. Animals treated with PDS or PS exhibited time-related increases in mEH mRNA levels, resulting in 2-6-fold elevations at 72-h post-treatment. The changes in mEH mRNA levels after ADS or AS treatment appeared to be more rapid than those after PDS or PS. The rank order for increases in mEH mRNA levels was ADS > AS > PS > PDS. The result of immunoblot analysis was consistent with that of Northern blot analysis. 4. Rats treated with isopropyl sulphide (IPS), butyl sulphone, tert-butyl sulphide, sec-butyl sulphide or butyl sulphide (100 mg/kg/day) showed 3-5-fold increases in the mEH mRNA levels at 3 days post-treatment. IPS treatment caused a similar increase in the mRNA level to that of PS, whereas the induction efficacy of PDS was lower than that of PS or IPS. Treatment with butyl sulphone as well as the structural isomers of butyl sulphides caused approximately 3-fold elevations in mEH mRNA levels. 5. These results provide evidence that alkyl sulphides, but not alkyl ethers, are capable of increasing mEH mRNA levels and that the organosulphur compounds with the allyl moiety are more effective in stimulating the mEH gene than are saturated alkyl sulphides. The comparable increase in mEH mRNA by butyl sulphone as well as the necessity of sulphur atom suggests that sulphone metabolites from the alkyl sulphides might be the ultimate inducers of mEH.

High level of urokinase-type plasminogen activator is a new prognostic marker in patients with gastric carcinoma

BACKGROUND

Prognosis of gastric carcinoma is related to invasion and metastasis. Evidence has accumulated that invasion and metastasis in solid tumors require the action of tumor-associated proteases, which promote the dissolution of the surrounding tumor matrix and the basement membrane. The serine protease urokinase-type plasminogen activator (uPA) and its inhibitor, plasminogen activator inhibitor-1 (PAI-1), appear to have a major function in these processes. Recent reports have demonstrated that expression of these proteolytic enzymes is elevated in breast and colon carcinoma and that it can be associated with invasiveness and poor prognosis. Therefore, the authors evaluated whether the expression and activation of uPA and PAI-1 might be of clinical value as a tumor/biologically defined risk factor in patients with gastric carcinoma.

METHODS

Enzyme-linked immunoadsorbent assays were used to test for uPA antigens and PAI-1 in tissue extracts of normal and cancerous tissue from 160 gastric carcinoma patients who were enrolled in the Yonsei Cancer Center Study Group.

RESULTS

Both uPA and PAI-1 levels were significantly higher in cancerous tissues than in normal tissues (uPA: 9.4 +/- 8.7 vs. 5.3 +/- 3.1 ng/mg protein cytosol; PAI-1: 10.9 +/- 9.1 vs. 5.8 +/- 2.9 ng/mg protein cytosol), (P < 0.001, respectively). Both high uPA and PAI-1 levels were associated with differentiation of the tumor (P = 0.04 and P = 0.004, respectively), and a high PAI-1 level was associated with lymph node metastasis at an advanced stage (P = 0.003 and P = 0.04, respectively). There was a correlation between the levels of uPA and PAI-1 expression in cancerous tissues (correlation coefficient = 0.57). In univariate analysis, a high level of uPA or PAI-1 was associated with a short relapse free survival, but in multivariate analysis only a high level of uPA was an independent prognostic parameter for a short relapse free survival for gastric carcinoma patients.

CONCLUSIONS

These data indicate that uPA is a new independent variable for the identification of high risk gastric carcinoma patients. Therefore, therapy targeting uPA can be applied as a new biologic treatment modality for these individuals.

Relationship between p53 overexpression and gastric cancer progression

The relationship between p53 overexpression and clinicopathologic variables in gastric cancer was evaluated using 304 paraffin-embedded gastric tumor tissues. DO7, a murine monoclonal antiserum to p53 protein, was used for the immunohistochemical analysis. Positive staining was found in 129 tumors (42.2% of all tumors). Overexpression of p53 was not associated with sex, location of the tumor in the stomach or the type of Borrman's tumor. The overexpression rate of p53 protein was 30.4% (28/92) in stage II and 47.6% (101/212) in stage III (p = 0.007). While there was no significant association between p53 protein accumulation and T stage, there was a significant association with N stage, i.e. p53 overexpression was 27.4% (17/62) in the node-negative group and 46.3% (112/242) in the node-positive group (p = 0.011). In 79 patients, in whom corresponding primary gastric tumor and regional lymph node metastases were available, overexpression was found in 34 (43%) primary tumors and in 38 (48.1%) node samples, with a concordance rate of 67.1% in terms of p53 expression. Mean numbers of regional lymph node involvement by the tumor were 6.1 in the group with p53 overexpression and 5.2 in the group showing no immunoreactivity (p = 0.051). These findings suggest that p53 overexpression is related to gastric cancer progression and that immunoreactivity in the metastatic lymph nodes show the dependency on p53 expression in the primary tumor.

Correlation between K-ras gene mutation and prognosis of patients with nonsmall cell lung carcinoma

BACKGROUND

Mutations at codons 12, 13, and 61 of the three ras genes, H-ras, K-ras, and N-ras, convert these genes into active oncogenes. It appears that ras gene mutations can be found in a variety of tumor types. The purpose of this study was to evaluate the clinical significance of K-ras gene mutation in nonsmall cell lung carcinoma (NSCLC).

METHODS

The authors analyzed 58 NSCLC patients for mutations at codons 12, 13, and 61 of the K-ras gene and correlated the findings with the tumor stage and patient survival. Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and the direct nucleotide sequencing method were used to detect mutations after amplification of ras specific sequences by PCR.

RESULTS

Fourteen mutations (24%) of ras genes were found, all at codon 12 of the K-ras gene. GGT to GAT transition was the predominant mutational pattern. There was a significant association between K-ras mutation and the tumor stage (i.e., the higher the stage, the higher the mutation rate) (P = 0.014). Using univariate analysis, the presence of K-ras mutation in paraffin embedded tissue from patients who received treatment with curative intent was associated with a shorter survival (P = 0.039). The median survival duration for patients with or without K-ras mutation was 9 and 30 months, respectively. The Cox proportional hazards model also predicted a higher risk for patients with K-ras mutations (P = 0.047).

CONCLUSIONS

K-ras mutations, present in a subset of NSCLC, are associated with tumor progression and shortened patient survival.

Rapid down-regulation of tyrosine hydroxylase expression in the olfactory bulb of naris-occluded adult rats

In most sensory systems, afferent innervation regulates morphological and biochemical characteristics of target cells for a limited time during development. Sensory deprivation experiments in adult rats also have suggested a critical period for afferent influences on olfactory bulb structure and function. Previous odorant deprivation studies that employed unilateral naris closure in neonatal rats demonstrated down-regulation of the catecholamine biosynthetic enzyme tyrosine hydroxylase (TH) in dopamine neurons intrinsic to the olfactory bulb. Accompanying the altered biochemical parameters was a decrease in bulb size. To distinguish between deprivation-induced alterations in TH expression secondary to developmental sequelae and those occurring in mature neurons, the consequences of unilateral naris closure were assessed in young adult rats. In agreement with previous studies significant postnatal increases occurred in TH expression and total protein, an indication of bulb size. At 30 days post-closure, total protein was unaltered in the ipsilateral olfactory bulb but showed a small (12.9%), significant decline at 60 days. In contrast to the limited morphological consequences of odor deprivation, profound reductions occurred in TH expression. TH activity ipsilateral to the closure decreased significantly by 14 days post-closure and remained depressed for up to 6 months. In parallel with enzyme activity, TH immunoreactivity did not decline in the first few days post-closure. In situ hybridization revealed that TH mRNA levels decreased rapidly, i.e., by 2 days post-closure, reached a nadir at 1 month, and remained depressed for at least 6 months. The capacity of odor deprivation in the adult rat olfactory system to down-regulate TH expression suggests that this phenotypic alteration occurs independently of a presumed critical period.

Overexpression of c-ErbB-2 protein in gastric cancer by immunohistochemical stain

An immunohistochemical stain to the c-ErbB-2 protein was performed in 225 paraffin-embedded tissue blocks from patients with locally advanced gastric cancer who underwent curative resection. The overexpression of the c-ErbB-2 protein was observed in 27.4% of the patients. The c-ErbB-2 positivity showed a statistically significant correlation with nodal status and stage. The patients with an overexpression of the c-ErbB-2 protein had a tendency to a shorter survival than those without, but it was not statistically significant (p = 0.08). The 5-year survival rate after surgery was 54% in the negative staining group to the c-ErbB-2 protein and 49% in the positive staining group. This suggests that the c-ErbB-2 protein has a possible role in lymph node metastasis. Therefore overexpression of the c-ErbB-2 protein is a useful indicator of disease progression in gastric carcinoma patients who received curative surgery.