Efficacy of retreatment with polatuzumab vedotin in combination with rituximab in polatuzumab vedotin-resistant DLBCL models

Polatuzumab vedotin (Pola) was approved for first-line and relapsed/refractory (r/r) diffuse large B-cell lymphoma (DLBCL) in many countries. This means that retreatment with Pola for r/r DLBCL could be considered after first-line Pola treatment; however, there is currently no evidence on the effectiveness of Pola-retreatment. To address this, we established two Pola-resistant cells from DLBCL cells (SU-DHL-4 and STR-428) and evaluated the combination efficacy of Pola plus rituximab (Rit), the key component of DLBCL therapy. MDR1 overexpression and decreased Bim expression were suggested to be the resistant mechanisms to Pola in Pola-resistant SU-DHL-4 and Pola-resistant STR-428, respectively. In these cells, Pola significantly increased Rit-induced CDC sensitivity either with increased MAC formation or reduced Mcl-1 expression. Additionally, treatment with Pola + Rit significantly enhanced antitumor activity in Pola-resistant STR-428 xenograft mouse models. Based on these results, Pola + Rit retreatment could have preserved efficacy because of the effect of Pola on sensitizing cells to Rit.

The molecular rationale for the combination of polatuzumab vedotin plus rituximab in diffuse large B-cell lymphoma

Polatuzumab vedotin (Pola) is an antibody-drug conjugate that targets the B-cell antigen CD79b and delivers monomethyl auristatin E (MMAE). It is approved in combination with bendamustine and rituximab (Rit) for relapsed/refractory diffuse large B-cell lymphoma (r/r DLBCL). Understanding the molecular basis of Pola combination therapy with Rit, the key component for the treatment of DLBCL, is important to establish the effective treatment strategies against r/r DLBCL. Here, we examined the rationale for the combination of Pola with Rit using Pola-refractory cells. We found that treatment with Pola increased CD20 expression and sensitivity to Rit-induced complement-dependent cytotoxicity (CDC) in several Pola-refractory cells. Pola treatment increased phosphorylation of AKT and ERK and both AKT- and MEK-specific inhibitors attenuated the Pola-induced increase of CD20 and CDC sensitivity, suggesting that these phosphorylation events were required for this combination efficacy. It was revealed that anti-CD79b antibody increased the phosphorylation of AKT but inhibited the phosphorylation of ERK. In contrast, MMAE potentiated phosphorylation of ERK but slightly attenuated the phosphorylation of AKT. Pola also increased CD20 expression on Pola-refractory xenografted tumours and significantly enhanced antitumour activity in combination with Rit. In conclusion, these results could provide a novel rationale for the combination of Pola plus Rit.

Adverse event profiles of hypomagnesemia caused by proton pump inhibitors using the Japanese Adverse Drug Event Report (JADER) Database

Proton pump inhibitors (PPIs) are commonly used for the prevention or treatment of gastric ulcers, but they can induce hypomagnesemia. Little is known about the onset duration and risk factors related to patient characteristics of this adverse event in Japanese patients. Therefore, we analyzed the time-to-onset of PPI-induced hypomagnesemia and evaluated the association between hypomagnesemia and PPIs using the Japanese Adverse Drug Event Report (JADER) database. We analyzed hypomagnesemia cases between 2004 and 2021. The time-to-onset analysis was performed using the Weibull distribution, and the adjusted reporting odds ratio (aROR) or 95% confidence interval (95% CI) was calculated using a multiple logistic regression analysis. The analysis database comprised 236,525 cases, with 188 cases associated with hypomagnesemia. The median onset duration (interquartile range) of PPI-induced hypomagnesemia was 99.0 (51.8-285.5 ) days, which is considered the random failure type. The multiple logistic regression analysis revealed that hypomagnesemia is significantly associated with male sex (aROR, 95% CI: 1.66, 1.23-2.25) , age < 60 (1.59, 1.14-2.21) , estimated body-mass index (eBMI) (0.94, 0.91-0.98) , PPIs (1.66, 1.18-2.30) , and the interaction of age (<60)*PPIs (1.58, 1.13-2.19) . However, diuretics were not significantly associated with hypomagnesemia. Our results suggest that serum magnesium levels should be measured regularly regardless of the duration of PPI use, especially in patients with male sex, age < 60, or low BMI. These findings will assist health professionals in the adequate use of PPIs. These findings need to be evaluated by cohort studies and long-term clinical investigations.

P-754 Perinatal outcomes and congenital anomalies after clomiphene citrate based minimal ovarian stimulation in vitro fertilisation stratified by embryo transfer method: a 10-year cohort study

Study question

Is the embryo transfer method associated with perinatal outcomes and congenital anomalies after minimal ovarian stimulation in vitro fertilisation (IVF) with clomiphene citrate (CC)?

Summary answer

Single vitrified-warmed blastocyst transfers in natural cycles had a lower incidence of pregnancy complications compared to single fresh cleaved embryo transfers after CC-based ovarian stimulation.

What is known already

Pregnancies resulting from IVF are associated with a higher risk of adverse perinatal outcomes compared to spontaneous conception; therefore, the next focus in reproductive medicine is to assess whether the increased risks are attributable to the IVF. Perinatal outcomes and congenital anomalies should be considered in addition to pregnancy outcomes in selecting the embryo transfer method. However, studies describing the influence of transfer methods on perinatal and maternal outcomes are limited.

Study design, size, duration

This study retrospectively analysed a single centre 10-year cohort. A total of 82,491 clinical records of women who underwent oocyte retrieval during a CC-based minimal stimulation cycle followed by single fresh cleaved embryo transfer (SFCT), single vitrified-warmed cleaved embryo transfer (SVCT), or single vitrified-warmed blastocyst transfer (SVBT) at the Kato Ladies Clinic between January 2008 and December 2017 were retrospectively analysed.

Participants/materials, setting, methods

The oocyte retrievals were performed in CC-based minimal ovarian stimulation. The embryos were transferred 2–3 days after retrieval, or vitrified at the cleavage or blastocyst stages. The vitrified embryos were warmed and transferred within the natural cycles. Perinatal outcomes and congenital anomalies were stratified by the transfer method. Multivariate logistic regression analysis was performed to evaluate the effect of transfer methods on pregnancy complications and congenital anomalies.

Main results and the role of chance

The perinatal outcomes and congenital anomalies in 19,069 singleton pregnancies were analysed. Multivariate logistic regression analysis revealed that the incidence of hypertensive disorders of pregnancy was significantly lower in the SVBT group compared with the SFCT group (adjusted odds ratio [AOR], 0.628; P &lt; 0.0001). The incidence of low-lying placenta (AOR 0.359 P = 0.0483; AOR 0.452 P &lt; 0.0001, respectively) and placenta previa (AOR 0.300 P = 0.0021; AOR 0.542 P &lt; 0.0001, respectively) were lower in the SVCT and SVBT groups than in the SFCT group. The rate of preterm delivery was lower in SVBT compared with SFCT (AOR 0.732 P &lt; 0.0001). The rate of low birth weight was significantly lower after SVCT and SVBT, compared with the SFCT group (AOR 0.751; P = 0.0261: AOR, 0.560; P &lt; 0.0001: respectively). A lower incidence of small for gestational age (AOR 0.720 P = 0.0436; AOR 0.494 P &lt; 0.0001, respectively) and higher incidence of large for gestational age (AOR 1.287 P = 0.0332; AOR 1.706 P &lt; 0.0001, respectively) were observed in the SVCT and SVBT groups compared to the SFCT group. The incidence of each congenital anomaly was similar among the groups.

Limitations, reasons for caution

The data was collected through self-reported parental questionnaires on neonatal outcomes and congenital malformations. Furthermore, this study was retrospective in nature; further studies are necessary to ascertain the generalisability of these findings to other clinics with different protocols and/or patient demographics.

Wider implications of the findings

This study demonstrated reassuring outcomes for SVBT, in terms of a lower incidence of pregnancy complications compared with SFCT. Our findings provide valuable knowledge to improve perinatal outcomes in CC-based stimulation and to inform couples of the possible benefits and harms of each type of embryo transfer method.

Trial registration number

not applicable

Coadministration with bendamustine restores the antitumor activity of obinutuzumab in obinutuzumab-resistant tumors

BACKGROUND

The glycoengineered, humanized anti-CD20 antibody obinutuzumab is indicated for previously untreated or relapsed/refractory CD20-positive follicular lymphoma (FL). However, the effectiveness of obinutuzumab retreatment in relapsed/refractory FL after prior obinutuzumab-containing therapy is unclear. To address this issue, we investigated the antitumor activity of obinutuzumab plus bendamustine in obinutuzumab-resistant tumors established from a human non-Hodgkin lymphoma xenograft model.

MATERIALS AND METHODS

Obinutuzumab-resistant tumors (SU-DHL-4-OR-18-8) were established from an SU-DHL-4 xenograft model by repeated administration of obinutuzumab. Antitumor activity was evaluated based on tumor volume after treatment with obinutuzumab on Day 1, 8, and 15 and/or bendamustine on Day 1 and 2. Intratumoral natural killer (NK) cells/macrophages were evaluated by immunohistochemistry and flow cytometry.

RESULTS

In SU-DHL-4-OR-18-8 xenografted tumors, intratumoral NK cells/macrophages after obinutuzumab treatment were significantly decreased compared with parent tumors on Day 4. The endoplasmic reticulum stress sensor phospho-IRE1 was also decreased. In SU-DHL-4-OR-18-8 tumors, bendamustine treatment increased phospho-IRE1 on Day 4 and intratumor NK cells/macrophages on Day 10. Obinutuzumab combined with bendamustine significantly increased antitumor activity compared with each single agent on Day 29, with an increase in chemoattractant CCL6 expression on Day 10.

CONCLUSIONS

Coadministration of bendamustine in obinutuzumab retreatment may be effective against obinutuzumab-resistant tumors.

Resistance to obinutuzumab-induced antibody-dependent cellular cytotoxicity caused by abnormal Fas signaling is overcome by combination therapies

Background

Obinutuzumab, a Type II anti-CD20 antibody, is used to treat follicular lymphoma. A major mode of action of obinutuzumab is antibody-dependent cellular cytotoxicity (ADCC). Knowledge of the mechanisms of resistance to obinutuzumab is important for the development of next-line strategies to follow obinutuzumab-containing therapy, including obinutuzumab retreatment. Unfortunately, the mechanisms by which tumor cells acquire resistance to ADCC are still poorly understood. To address this, we examined the mechanisms of resistance to obinutuzumab-induced ADCC and the combination efficacy of obinutuzumab and clinically available agents in the established resistant cells.

Methods and results

We established cells resistant to obinutuzumab-induced ADCC using the non-Hodgkin lymphoma cell line RL and examined their mechanisms of resistance and the combination efficacy of obinutuzumab and clinically available agents. Comprehensive analysis by RNA sequencing of resistance mechanisms revealed that abnormal Fas signaling decreased sensitivity to ADCC in resistant clones. Combination treatment with prednisolone, a component of CHOP and CVP, was found to enhance ADCC sensitivity of RL cells and resistant clones and to significantly suppress tumor growth in xenograft models. Treatment with prednisolone upregulated expression of CD20 and an apoptosis-inducing protein BIM, which might augment perforin/granzyme B-mediated cell death. Furthermore, pretreatment of the effector cells with bendamustine enhanced ADCC activity, and treatment with obinutuzumab plus bendamustine showed significant antitumor efficacy in xenograft models. It was speculated that bendamustine upregulates ADCC activity by potentiating granules-mediated cell killing.

Conclusions

Our study revealed a novel mechanism underlying obinutuzumab-induced ADCC resistance and indicated that ADCC resistance could be overcome by combining obinutuzumab with prednisolone or bendamustine. This study provides a scientific rationale for obinutuzumab-retreatment in combination with clinically available chemotherapeutic agents for obinutuzumab resistant follicular lymphoma.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11033-022-07280-w.

Time-dependent changes in serum magnesium levels in patients receiving cetuximab with low baseline serum sodium levels

Cetuximab causes electrolyte abnormalities, such as hypomagnesemia, hypokalemia, and hypocalcemia. However, little is known about the relationships between the onset of hypomagnesemia, patient background before administration, and time-dependent changes in serum magnesium levels. Therefore, we examined the patient backgrounds that influenced the onset of hypomagnesemia and the time-dependent changes in serum magnesium levels in patients receiving cetuximab. A retrospective study was performed to investigate patients with advanced or recurrent colorectal cancer or head and neck cancer, treated with a cetuximab regimen from 2012 to 2020 at Kindai University Nara Hospital. In total, 52 patients who met the inclusion criteria were enrolled in this study. The serum magnesium level was significantly lower in the hyponatremia before the administration group than in the non-hyponatremia group (p < 0.001). Univariate logistic regression analysis revealed that the baseline serum sodium levels (odds ratio [OR]: 0.741, 95% confidence interval [CI]: 0.588-0.934) and the combination of magnesium oxide tablet (OR: 0.997, 95% CI: 0.995-0.999) were one of the independent factors for hypomagnesemia. These results indicated that hyponatremia before administration may be an indicator of serum magnesium levels after administration of cetuximab. Cetuximab-induced hypomagnesemia may be predicted using baseline serum sodium levels, and hypomagnesemia may be prevented by administration of magnesium oxide tablets. Our findings provided new evidence for the management of serum magnesium levels in patients receiving cetuximab.

Obinutuzumab in Combination with Chemotherapy Enhances Direct Cell Death in CD20-Positive Obinutuzumab-resistant Non-Hodgkin Lymphoma Cells

Follicular lymphoma commonly recurs and is difficult to cure. Obinutuzumab is a humanized glycoengineered type II anti-CD20 antibody with a mode of action that includes induction of antibody-dependent cellular cytotoxicity, antibody-dependent cellular phagocytosis, and direct cell death. There is no evidence on the effectiveness of retreatment with obinutuzumab in patients with prior obinutuzumab treatment. Using obinutuzumab-induced direct-cell-death-resistant cells, we investigated the efficacy of obinutuzumab retreatment in combination with chemotherapeutic agents used in follicular lymphoma treatment. Human non-Hodgkin lymphoma SU-DHL-4 cells were sustainably exposed to obinutuzumab in vitro, and 17 resistant clones expressing CD20 and showing 100-fold higher IC₅₀ of obinutuzumab than parental cells were established. The growth inhibition effect of obinutuzumab in combination with bendamustine, 4-hydroperoxy-cyclophosphamide, doxorubicin, vincristine, or prednisolone was estimated using an interaction index based on the Bliss independence model. For each clone, there were various combinations of obinutuzumab and chemotherapeutic agents that showed supra-additive effects. Obinutuzumab combined with doxorubicin enhanced caspase-dependent apoptosis and growth inhibition effect. Obinutuzumab combined with prednisolone enhanced DNA fragmentation and G₀-G₁ arrest. These combinations also had an antitumor effect in mouse xenograft models. Our results indicate that retreatment with obinutuzumab, when it is combined with chemotherapeutic agents, is effective in the CD20-positive obinutuzumab-induced direct-cell-death-resistant cells.

P1546 Reproducibility of right atrial myocardial deformation by two-dimensional speckle tracking

Background

Right atrial (RA) deformation by two-dimensional speckle tracking echocardiography has a relatively new technique to evaluate right heart function with pulmonary hypertension and cardiomyopathy. Reproducibility between observers of this technique is important to develop into a robust and reliable tool. Experience may pose significant challenges.

Purpose

The aim of this study is to evaluate reproducibility of RA strain (global and regional) between novice and expert.

Methods

One hundred thirty-three patients (n = 133) underwent 2D-Speckle tracking derived RA strain analysis by 3 independent blinded readers (expert and 2 novices). The novice observers were medical interns with no prior experience in performing strain analysis. Echocardiographic images were acquired from iE33 (Philips Medical System) but were analysed offline using single vendor dependent software (QLAB version 11.0; Philips Medical System). The result of novice observer was calculated by the average of novice observers. RA strain parameters were assessed: global RA strain and segmental (Basal, Mid, Roof). Intraobserver and interobserver analyses were performed using intra class correlation coefficients (ICC) between expert and novice.

Results

Expert and novice observer demonstrated good interobserver reproducibility of global RA strain (ICC 0.88) and segmental parameters (Basal: ICC 0.89, Mid: ICC 0.87, Roof: ICC 0.84). Of all parameters, the basal segment of RA strain showed the greatest interobserver agreement. Intraobserver agreement for novice observer was excellent for global RA strain and segmental parameters (ICC &gt; 0.88).

Conclusions

Global RA strain and segmental parameters were highly reproducible by novice and expert strain observer.

JUNB governs a feed-forward network of TGFβ signaling that aggravates breast cancer invasion

It is well established that transforming growth factor-β (TGFβ) switches its function from being a tumor suppressor to a tumor promoter during the course of tumorigenesis, which involves both cell-intrinsic and environment-mediated mechanisms. We are interested in breast cancer cells, in which SMAD mutations are rare and interactions between SMAD and other transcription factors define pro-oncogenic events. Here, we have performed chromatin immunoprecipitation (ChIP)-sequencing analyses which indicate that the genome-wide landscape of SMAD2/3 binding is altered after prolonged TGFβ stimulation. De novo motif analyses of the SMAD2/3 binding regions predict enrichment of binding motifs for activator protein (AP)1 in addition to SMAD motifs. TGFβ-induced expression of the AP1 component JUNB was required for expression of many late invasion-mediating genes, creating a feed-forward regulatory network. Moreover, we found that several components in the WNT pathway were enriched among the late TGFβ-target genes, including the invasion-inducing WNT7 proteins. Consistently, overexpression of WNT7A or WNT7B enhanced and potentiated TGFβ-induced breast cancer cell invasion, while inhibition of the WNT pathway reduced this process. Our study thereby helps to explain how accumulation of pro-oncogenic stimuli switches and stabilizes TGFβ-induced cellular phenotypes of epithelial cells.

Search for K_{L}→π^{0}νν[over ¯] and K_{L}→π^{0}X^{0} Decays at the J-PARC KOTO Experiment

A search for the rare decay K_{L}→π^{0}νν[over ¯] was performed. With the data collected in 2015, corresponding to 2.2×10^{19} protons on target, a single event sensitivity of (1.30±0.01_{stat}±0.14_{syst})×10^{-9} was achieved and no candidate events were observed. We set an upper limit of 3.0×10^{-9} for the branching fraction of K_{L}→π^{0}νν[over ¯] at the 90% confidence level (C.L.), which improved the previous limit by almost an order of magnitude. An upper limit for K_{L}→π^{0}X^{0} was also set as 2.4×10^{-9} at the 90% C.L., where X^{0} is an invisible boson with a mass of 135  MeV/c^{2}.

Long noncoding RNA NORAD regulates transforming growth factor-β signaling and epithelial-to-mesenchymal transition-like phenotype

Long noncoding RNAs are involved in a variety of cellular functions. In particular, an increasing number of studies have revealed the functions of long noncoding RNA in various cancers; however, their precise roles and mechanisms of action remain to be elucidated. NORAD, a cytoplasmic long noncoding RNA, is upregulated by irradiation and functions as a potential oncogenic factor by binding and inhibiting Pumilio proteins (PUM1/PUM2). Here, we show that NORAD upregulates transforming growth factor-β (TGF-β) signaling and regulates TGF-β-induced epithelial-to-mesenchymal transition (EMT)-like phenotype, which is a critical step in the progression of lung adenocarcinoma, A549 cells. However, PUM1 does not appear to be involved in this process. We thus focused on importin β1 as a binding partner of NORAD and found that knockdown of NORAD partially inhibits the physical interaction of importin β1 with Smad3, inhibiting the nuclear accumulation of Smad complexes in response to TGF-β. Our findings may provide a new mechanism underlying the function of NORAD in cancer cells.

Dynamics of chromatin accessibility during TGF-β-induced EMT of Ras-transformed mammary gland epithelial cells

Epithelial-mesenchymal transition (EMT) is induced by transforming growth factor (TGF)-β and facilitates tumor progression. We here performed global mapping of accessible chromatin in the mouse mammary gland epithelial EpH4 cell line and its Ras-transformed derivative (EpRas) using formaldehyde-assisted isolation of regulatory element (FAIRE)-sequencing. TGF-β and Ras altered chromatin accessibility either cooperatively or independently, and AP1, ETS, and RUNX binding motifs were enriched in the accessible chromatin regions of EpH4 and EpRas cells. Etv4, an ETS family oncogenic transcription factor, was strongly expressed and bound to more than one-third of the accessible chromatin regions in EpRas cells treated with TGF-β. While knockdown of Etv4 and another ETS family member Etv5 showed limited effects on the decrease in the E-cadherin abundance and stress fiber formation by TGF-β, gene ontology analysis showed that genes encoding extracellular proteins were most strongly down-regulated by Etv4 and Etv5 siRNAs. Accordingly, TGF-β-induced expression of Mmp13 and cell invasiveness were suppressed by Etv4 and Etv5 siRNAs, which were accompanied by the reduced chromatin accessibility at an enhancer region of Mmp13 gene. These findings suggest a mechanism of transcriptional regulation during Ras- and TGF-β-induced EMT that involves alterations of accessible chromatin, which are partly regulated by Etv4 and Etv5.

Ras and TGF-β signaling enhance cancer progression by promoting the ΔNp63 transcriptional program

The p53 family of transcription factors includes p63, which is a master regulator of gene expression in epithelial cells. Determining whether p63 is tumor-suppressive or tumorigenic is complicated by isoform-specific and cellular context-dependent protein associations, as well as antagonism from mutant p53. ΔNp63 is an amino-terminal-truncated isoform, that is, the predominant isoform expressed in cancer cells of epithelial origin. In HaCaT keratinocytes, which have mutant p53 and ΔNp63, we found that mutant p53 antagonized ΔNp63 transcriptional activity but that activation of Ras or transforming growth factor-β (TGF-β) signaling pathways reduced the abundance of mutant p53 and strengthened target gene binding and activity of ΔNp63. Among the products of ΔNp63-induced genes was dual-specificity phosphatase 6 (DUSP6), which promoted the degradation of mutant p53, likely by dephosphorylating p53. Knocking down all forms of p63 or DUSP6 and DUSP7 (DUSP6/7) inhibited the basal or TGF-β-induced or epidermal growth factor (which activates Ras)-induced migration and invasion in cultures of p53-mutant breast cancer and squamous skin cancer cells. Alternatively, overexpressing ΔNp63 in the breast cancer cells increased their capacity to colonize various tissues upon intracardiac injection in mice, and this was inhibited by knocking down DUSP6/7 in these ΔNp63-overexpressing cells. High abundance of ΔNp63 in various tumors correlated with poor prognosis in patients, and this correlation was stronger in patients whose tumors also had a mutation in the gene encoding p53. Thus, oncogenic Ras and TGF-β signaling stimulate cancer progression through activation of the ΔNp63 transcriptional program.

Nuclear accumulation of annexin A2 contributes to chromosomal instability by coilin-mediated centromere damage

Most human cancers show chromosomal instability (CIN), but the precise mechanisms remain uncertain. Annexin A2 is frequently overexpressed in human cancers, and its relationship to tumorigenesis is poorly understood. We found that annexin A2 is overexpressed in the nuclei of CIN cells compared with cells with microsatellite instability (MIN). Ectopic annexin A2 expression in MIN cells results in a high level of aneuploidy and induces lagging chromosomes; suppression of annexin A2 in CIN cells reduces such CIN signatures with apoptosis of highly aneuploid cells. Ectopic expression of annexin A2 in MIN cells reduces the expression of centromere proteins. Conversely, annexin A2-knockdown in CIN cells increases the expression of centromere proteins. Moreover, the endogenous expression levels of centromere proteins in CIN cells were greatly reduced compared with MIN cell lines. The reduced expression of centromere proteins likely occurred due to aberrant centromere localization of coilin, a major component of the Cajal bodies. These results suggest that nuclear accumulation of annexin A2 has a crucial role in CIN by disrupting centromere function.

Prediction of recurrence after laparoscopic fundoplication for erosive reflux esophagitis based on anatomy–function–pathology (AFP) classification

BACKGROUND

The usefulness of the anatomy-function-pathology (AFP) score was examined to evaluate its prediction of recurrence after laparoscopic fundoplication for erosive reflux esophagitis.

METHODS

Of the patients undergoing laparoscopic fundoplication for erosive reflux esophagitis of Los Angeles classification grade A or higher from December 1994 to December 2004, 107 who underwent preoperative barium esophagogram, pH monitoring, and endoscopy were selected as subjects. The AFP score was calculated by A, F, and P factor grades of the AFP classification. By comparing patients with and without recurrence, the usefulness of the AFP score for predicting recurrence was examined.

RESULTS

Reflux esophagitis recurred in seven patients. No significant difference in age, sex, or A or F factor was observed between the groups, whereas a significant difference was observed in the P factor (p = 0.008). On the other hand, the mean AFP score in the recurrence group was 16.9 +/- 5.3, whereas that in the nonrecurrence group was 8.9 +/- 5.3 (p = 0.0021). Among the patients with a score of 17 points or more (n = 23), recurrence was found in 6 patients (26%). On the other hand, among the patients with a score lower than 17 points (n = 84), recurrence was found in 1 patient, but not in the remaining 83 patients (1%). Sensitivity was thus 85.7% (95% confidence interval [CI], 42.1-99.6), and specificity was 83% (95% CI, 74.2-89.8). The positive predictive value was 26.1% (95% CI, 10.2-48.4), and the negative predictive value was 98.8% (95% CI, 93.5-99.9). Multiple logistic regression analysis was performed, and receiver operating characteristics curves were obtained. The area under the curve for the AFP score was 0.8457, whereas that for the P factor was 0.7907 (p = 0.0045), suggesting that the AFP score may more accurately predict recurrence than the P factor.

CONCLUSION

The AFP score may be useful for predicting postoperative recurrence. If surgery is performed when the AFP score is lower than 17 points, the likelihood of postoperative recurrence is expected to be very low.

Hand-assisted laparoscopic and thoracoscopic surgery (HALTS) in radical esophagectomy with three-field lymphadenectomy for thoracic esophageal cancer

AIM

To prove the feasibility of hand-assisted laparoscopic and thoracoscopic surgery (HALTS) for radical esophagectomy with three-field lymphadenectomy to thoracic esophageal cancer.

METHODS

Esophagectomy with three-field lymphadenectomy was performed using HALTS in 19 patients with thoracic esophageal cancer without distant metastasis. Five patients had chemo-radiotherapy prior to surgery.

RESULTS

All operations were completed successfully without the need for open surgery. Mean surgical time was 476+/-58 min, and mean blood loss during surgery was 343+/-184 mL. All patients started tube feeding and were moved from the intensive care unit to the general surgery ward the day after surgery. Discharge occurred a median of 10 days after surgery. Fifteen patients could return to full time jobs from 8 to 62 days after surgery (median 22 days) and from 1 to 35 days after discharge (median 9 days). Other three could return to daily activities at home soon as well. No major complications occurred, except one anastomotic leak. In terms of lung function, %FEV(1) was not changed whereas %VC was reduced significantly 1 month after surgery. All but two recurrences have been healthy without a relapse for a mean of 289 days.

CONCLUSIONS

These results suggest that HALTS may be a useful surgical technique to reduce the invasiveness of conventional radical esophagectomy with three-field lymphadenectomy for thoracic esophageal cancer.

Laparoscopic Heller myotomy and Dor fundoplication for the treatment of achalasia

BACKGROUND

The significance of laparoscopic Heller myotomy and Dor fundoplication (LHD) for the treatment of achalasia in relation to the severity of the lesion has not been sufficiently assessed.

METHODS

Of patients who were diagnosed with achalasia from August 1994 to February 2004, 55 individuals who underwent LHD served as subjects. The therapeutic effects of LHD were assessed in terms of operation time, intraoperative complications, postoperative hospital stay, and symptom improvement in relation to morphologic type (spindle type, Sp; flask type, Fk; and sigmoid type, Sig). Degree of symptomatic improvement was classified into four grades: excellent, good, fair, and poor.

RESULTS

Breakdown of morphologic type was as follows: Sp, n = 29; Fk, n = 18; and Sig, n = 8. Excluding one patient for whom conversion to open surgery was required, median average operation time for 54 patients was 160 min. As to intraoperative complications, esophageal mucosal perforation was seen in nine of the 55 patients (16%); however, conversion to open surgery could be avoided by suturing the affected area. Moreover, intraoperative bleeding of at least 100 g was seen in five of the 55 patients (9%), with one Fk patient requiring conversion to open surgery and transfusion. Median postoperative hospital stay was 8 days. Degree of dysphagia relief was excellent in 45 patients (83%), good in eight patients (15%), and fair in one patient (2%). Excellent improvement was obtained in 90%, 88%, and 50% in Sp, Fk, and Sig patients, respectively. Reflux esophagitis was seen in two patients, and was treated with a proton pump inhibitor.

CONCLUSIONS

The results of the present study suggest that classification of morphologic type is a useful parameter in predicting postoperative outcome in achalasia. In order to achieve excellent symptomatic relief, surgery for achalasia should be recommended for but not limited to Sp and Fk types.

Survival impact of epidermal growth factor receptor overexpression in patients with non-small cell lung cancer: a meta-analysis

BACKGROUND

It is thought that overexpression of epidermal growth factor receptor (EGFR) in non-small cell lung cancer (NSCLC) might compromise patient survival, presumably by promoting tumour growth by an autocrine mechanism. However, conflicting results have been reported from various laboratories, and the clinical importance of EGFR overexpression remains unsettled.

METHODS

A meta-analysis of previous studies was performed to quantitatively review the effects of EGFR overexpression on survival in patients with NSCLC using a DerSimonian-Laird random effects model. Eighteen studies including 2972 patients were subjected to final analysis.

RESULTS

Overall, positivity for EGFR overexpression differed between histological types: 39% in adenocarcinomas, 58% in squamous cell carcinomas, 38% in large cell carcinomas, and 32% in cancers in a miscellaneous category (p<0.0001). The combined hazard ratio (HR) was 1.14 (95% CI 0.97 to 1.34; p = 0.103), indicating that EGFR overexpression has no significant impact on survival. When only the 15 immunohistochemistry based studies were considered, the combined HR was 1.08 (95% CI 0.92 to 1.28; p = 0.356), again suggesting that EGFR overexpression has no impact on survival. Heterogeneity testing indicated that there was heterogeneity between studies but publication bias was absent, which suggests that the summary statistics obtained may approximate the actual average.

CONCLUSIONS

EGFR overexpression was not associated with poorer survival in patients with NSCLC. Specific mutations of the EGFR gene will need further study in terms of survival implications.

Survival following lobectomy vs limited resection for stage I lung cancer: a meta-analysis

Extent of resection needed to treat lung cancer has long been an issue. The sole randomised controlled trial, reported by the Lung Cancer Study Group, advised against limited resection as standard surgery even for small peripheral non-small-cell lung cancers (⩽3 cm), because of frequent local recurrences. Elsewhere, conflicting results have been reported from different institutions. We therefore conducted a meta-analysis of reported studies to compare survival of stage I patients between limited resection and standard lobectomy. A MEDLINE web search for computer-archived bibliographic data yielded 14 articles suitable for analysis. Combined survival differences (survival rate with lobectomy minus that with limited resection) at 1, 3, and 5 years after resection according to the DerSimonian–Laird random effects model were 0.7% (95% CI, −0.8 to 2.1; P=0.3659), 1.9% (95% CI, −3.7 to 7.4; P=0.5088), and 3.6% (95% CI, −0.4 to 10.5; P=0.3603), respectively. None of these survival differences were significant, indicating that survival after limited resection for stage I lung cancer was comparable to that after lobectomy. However, since interstudy heterogeneity was detected, caution is required in interpretation of the results.

Morphological change of the micelle of poly(styrene)-b-poly(2-vinylpyridine)-b-poly(ethylene oxide) induced by binding of sodium dodecyl sulfate

Morphological change of a micelle of poly(styrene)-b-poly(2-vinylpyridine)-b-poly(ethylene oxide) (PS-PVP-PEO) polymer was induced by binding sodium dodecyl sulfate (SDS) to the PVP block in acidic aqueous solutions. The change in the size of SDS/PS-PVP-PEO complexes was detected by dynamic light scattering measurements and atomic force microscopy, and the binding of SDS was confirmed by zeta-potential measurements. When the micelle was free from SDS in acidic aqueous solutions, the hydrodynamic diameter of the micelle was 216 nm, reflecting the extended conformation of the PVP block due to the repulsion between protonated pyridine units. As the cationic PVP block was electrically neutralized with anionic SDS, the diameter was gradually reduced concomitant with the decrease in zeta-potential and finally reached 175 nm when the PVP block was completely neutralized. The decrease in the diameter shows the morphological change of the PVP block from extended to shrunken forms. Further addition of SDS did not cause the changes of the diameter nor zeta-potential. This indicates that SDS was not bound to the PS-PVP-PEO polymer after the PVP block was fully neutralized and that the hydrophobic binding of SDS to the polymer was negligible due to the low concentration of SDS.

Excision of pseudotumour in a patient with haemophilia A and inhibitor managed with recombinant factor VIIa

We describe a patient with haemophilia A and factor VIII inhibitor who underwent surgical excision of a large pseudotumour in the left femoral region. Haemostasis was successfully maintained with bolus doses of recombinant factor VIIa at 2-h intervals and anti-fibrinolytic therapy, and the pseudotumour was removed. Subsequently, the dose interval was gradually prolonged to 8 h for a total of 18 days. Although a spontaneous haemorrhage was observed on postoperative day 8, haemostasis was achieved by reducing the dosage interval. No adverse event occurred during the course of treatment.

Endothelin protein expression as a significant prognostic factor in oesophageal squamous cell carcinoma

The aim of this study was to investigate if the expression of endothelin (ET), a vasoactive peptide, in cancerous oesophageal lesions, adjacent dysplastic tissue and normal mucosa might be prognostic. Tissue samples from a total of 101 patients with oesophageal squamous cell carcinoma were obtained and stained with ET antibody in an immunohistochemical analysis. High staining levels of ET within normal mucosa were related to lymph vessel invasion, regional lymph node metastasis and distant metastasis, as well as a reduced relapse-free survival (log-rank test; P=0.0066). After adjustment for several histological prognostic risk factors and each component of the TNM classification system, high ET expression within dysplastic tissue more than doubled the hazard ratio of relapse with significant model improvement. These results suggest that, in addition to known histological risk factors and TNM classification criteria, measurement of ET expression with a simple immunohistochemical analysis might further help in predicting the prognosis of patients with oesophageal squamous cell carcinoma.

Three new alleles of IGHG2 and their prevalence in Danish Caucasians, Mozambican Blacks and Japanese

The human IGHG2 gene locus is polymorphic, encoding two known allotypes of IgG2: G2m(n-) and G2m(n+). The allele prevalence varies greatly between different ethnic groups and individual genotypes correlate with the level of plasma IgG2 and with antibody responses to certain polysaccharide antigens. In this study, we present three new alleles of IGHG2 (IGHG2*03, 04, and 05), and a complete sequence specific PCR typing system allowing discrimination between the different allotypes of IgG2. A hitherto unknown allotype, which we name G2m(ny), is encoded by IGHG2*04 and differs from G2m(n-) by asparagine rather than serine in CH1 residue 75 and by phenylalanine rather than leucine in CH1 residue 76 (EU numbering 192 and 193). The polymorphic residues are probably surface exposed near the hinge region. The same residues are also found in IgG1, IgG3, and IgG4, and G2m(ny) is therefore an isoallotype that probably arises by gene conversion within the heavy chain locus. The IGHG2*04 allele is present among Danish Caucasians with a low prevalence (2.5%), but was not found in Japanese or Mozambicans. The two other new alleles (IGHG2*03 and IGHG2*05) both encode the G2m(n-) allotype. The IGHG2*03 allele encodes most of the IgG2 of the G2m(n-) allotype in Danish Caucasians.

Percutaneous absorption of non-steroidal anti-inflammatory drugs from in situ gelling xyloglucan formulations in rats

The potential of gels formed in situ by dilute aqueous solutions of a xyloglucan polysaccharide derived from tamarind seed as sustained release vehicles for percutaneous administration of non-steroidal anti-inflammatory drugs has been assessed by in vitro and in vivo studies. Chilled aqueous solutions of xyloglucan that had been partially degraded by beta-galactosidase formed gels at concentrations of 1-2% w/w when warmed to 37 degrees C. The in vitro release of ibuprofen and ketoprofen at pH 7.4 from the enzyme degraded xyloglucan gels and the subsequent permeation of these fully ionized drugs through cellulose membranes followed root-time kinetics over a period of 12 h after an initial lag period. Diffusion coefficients were appreciably higher when the drugs were released from 1.5% w/w xyloglucan gels than when released from 25% w/w Pluronic F127 gels formed in situ under identical conditions. The difference in release rates was attributed to differences in the structure of the gels. The permeation rate of ibuprofen through excised skin was higher than that of ketoprofen when released from both gels, but of similar magnitude through cellulose membranes. Plasma concentrations of ibuprofen and ketoprofen from gels formed in situ following topical application of chilled aqueous solutions of xyloglucan and Pluronic F127 to the abdominal skin of rats were compared. The bioavailabilities of ibuprofen and ketoprofen were significantly higher when released from xyloglucan gels compared to Pluronic F127 gels. Occlusive dressing techniques had a greater enhancing effect on the bioavailability of ibuprofen when released from Pluronic gels.

[Study on evaluating methods for the quality control of glycoprotein products. (III)--Erythropoietin products. Part 3]

We reported previously that peptide mapping using high-performance liquid chromatography with electrospray ionization mass spectrometry (LC/MS) and liquid chromatography with tandem mass spectrometry (LC/MS/MS) are useful for determination of the glycosylation sites, carbohydrate structure, and site-specific carbohydrate heterogeneity of glycoproteins. Here, with intention to enhance the sensitivity and shorten the time-span of analysis to characterize glycoproteins, especially biotechnological products with carbohydrate moieties, we studied the introduction of HPLC with a microbore column to LC/MS with recombinant erythropoietin (rh-EPO). In addition, we evaluated the ability of LC/MS/MS precursor-ion scanning to make identification of glycopeptides and facilitate the analysis of carbohydrate moieties. We found that the peptide mapping with microbore HPLC is highly sensitive and more rapid than the previous method, and the precursor-ion scanning is helpful for identifying glycopeptides. Our results indicate that these methods are very useful for characterization and quality control of the carbohydrate moieties of biotechnological products.

[Rapid quantitation of follistatin by surface plasmon resonance (SPR) immunoassay]

A simple, rapid, and accurate assay using surface plasmon resonance (SPR) apparatus with anti-follistatin antibody (SPR immunoassay) has been developed for the quantitation of recombinant follistatin. This assay can be performed with a direct injection of conditioned medium; results were obtained within 10 min. The quantitation component of this assay was precise and accurate with a limit of quantitation of 62.5 ng/ml in Ham's F12 medium containing 2% fetal bovine serum. These results demonstrate that SPR immunoassay is a powerful technique for several researches, especially for screening of gene transfectant and monitoring of protein production.

Structural analysis of sulfated N-linked oligosaccharides in erythropoietin

We previously demonstrated that high-performance liquid chromatography with electrospray ionization mass spectrometry (LC/MS) equipped with a graphitized carbon column (GCC) is useful for the structural analysis of carbohydrates in glycoproteins. Using LC/MS with GCC, sulfated N-linked oligosaccharides were found in erythropoietin (EPO) expressed in baby hamster kidney cells. Sulfation occurs in a part of the N-linked oligosaccharides in the EPO. Sulfated monosaccharide residue in the sulfated N-linked oligosaccharide was determined by exoglycosidase digestion followed by sugar mapping by LC/MS. The linkage position and branch-location of the sulfate group in the tetraantennary oligosaccharide were analyzed by (1)H-nuclear magnetic resonance. It was suggested that sulfation occurs on the C-6 position of GlcNAc located in the GlcNAcbeta1-4Manalpha1-3 branch.

Ganglioside GD1a inhibits HGF-induced motility and scattering of cancer cells through suppression of tyrosine phosphorylation of c-Met

We previously reported that ganglioside GD1a, which is highly expressed in poorly metastatic FBJ-S1 cells, inhibits the serum-induced motility of FBJ-LL cells and that the metastatic potential of FBJ-LL cells is completely suppressed by enforced GD1a expression (Hyuga et al., Int J Cancer 1999;83:685-91). We recently discovered that hepatocyte growth factor (HGF) induces FBJ-LL cell motility. In the present study, the HGF-induced motility of FBJ-S1 cells was found to be one-thirtieth that of FBJ-LL cells. This motility of GD1a-expressing transfectants, which were produced by transfection of FBJ-LL cells with GM2/GD2 synthase cDNA, decreased with increases in their GD1a expression and HGF induced almost no motility in GD1a-pretreated FBJ-LL cells, indicating that GD1a inhibits the HGF-induced motility of FBJ-LL cells. The expression of the HGF receptor c-Met on FBJ-S1 cells, FBJ-LL cells, transfectants and a mock-transfectant was almost the same. The level of tyrosine phosphorylation of c-Met after HGF stimulation in FBJ-S1 cells, GD1a-pretreated FBJ-LL cells and a GD1a-expressing transfectant was significantly lower than in FBJ-LL cells and a mock-transfectant. These findings suggested that GD1a inhibits the HGF-induced motility of FBJ-LL cells through suppression of tyrosine phosphorylation of c-Met. HepG2 cells, a human hepatoma cell line, were used to investigate whether GD1a interferes with other cancer cells expressing c-Met. HepG2 cells did not express GD1a. HGF induced cell scattering of HepG2 cells and the scattering was inhibited by pretreating the cells with GD1a. The c-Met in the cells was autophosphorylated by stimulation with HGF, but after treating the cells with GD1a, the HGF-induced autophosphorylation of c-Met was suppressed. These results suggest that GD1a acts as a negative regulator of c-Met in cancer cells.

In situ gelling xyloglucan formulations for sustained release ocular delivery of pilocarpine hydrochloride

Thermoreversible gels formed in situ by aqueous solutions of an enzyme-degraded xyloglucan polysaccharide were evaluated as sustained release vehicles for the ocular delivery of pilocarpine hydrochloride. In vitro release of pilocarpine from gels formed by warming xyloglucan sols (1.0, 1.5 and 2.0% w/w) to 34 degrees C followed root-time kinetics over a period of 6 h. The miotic responses in rabbit following administration of xyloglucan sols were compared with those from in situ gelling Pluronic F127 sols and from an aqueous buffer solution containing the same drug concentration. Sustained release of pilocarpine was observed with all gels, the duration of miotic response increasing with increase of xyloglucan concentration. The degree of enhancement of miotic response following sustained release of pilocarpine from the 1.5% w/w xyloglucan gel was similar to that from a 25% w/w Pluronic F127 gel.

Oral sustained delivery of theophylline from thermally reversible xyloglucan gels in rabbits

Thermally reversible gels formed in-situ following the oral administration of dilute aqueous solutions of an enzyme-degraded xyloglucan to rabbits were evaluated as sustained-release vehicles for the delivery of theophylline. In-vitro release of theophylline from gels formed by warming xyloglucan sols (0.5, 1.0 and 1.5% w/w) to 37 degrees C followed root-time kinetics over a period of 4 h. Gels formed after oral administration to rabbits of chilled 1.5% w/w aqueous solutions of xyloglucan containing dissolved drug showed sustained-release characteristics with a maximum plasma concentration at 4.5 h. The theophylline bioavailability from a 1.5% w/w xyloglucan gel was 1.7-2.5 times that of commercial oral sustained-release liquid dosage forms containing an identical theophylline concentration. It was concluded that dilute solutions of the enzyme-degraded xyloglucan had suitable rheological properties and in-situ gelling characteristics for use as sustained-release vehicles for oral drug delivery. The in-vivo release characteristics of theophylline in a rabbit model suggested the potential for the use of these vehicles in humans for the oral delivery of this drug.

Wistar strain rats as the model for IgE antibody experiments

The amount of plasma IgE antibody formed and its change over time were investigated by enzyme-linked immunosorbent assay (ELISA) in male and female Sprague-Dawley (SD), Donryu, and Wistar strain rats. IgE antibody formation was initiated by injecting a mixture of 2,4-dinitrophenylated ascaris extract (DNP-As) as antigen and killed Bordetella pertussis as adjuvant into the paws of the animals. The amount of IgE antibody formed was low on day 10 in both male and female SD (40-80 ng/ml) and Donryu (20-40 ng/ml) strain rats, and an increase in the amount was observed on day 20. The peak value of IgE antibody was observed day 10 in Wistar strain rats and was 130 and 200 ng/ml in the male and female rats, respectively. These results suggest that Wistar strain rats produce the most IgE antibody when DNP-As is used as antigen and they can serve as a model for allergic diseases.

Early hilar lung cancer--risk for multiple lung cancers and clinical outcome

In early hilar lung cancer patients, multiple lung cancers frequently develop. The clinical outcome of such patients were studied. A total of 91 patients, 88 men and three women, who were endoscopically diagnosed with early hilar lung cancer were studied retrospectively. Surgery was performed in 46 patients, while organ-sparing treatment, including photodynamic therapy (PDT), Nd-YAG (neodymium-yttrium, argon, garnet) laser vaporization, and radiotherapy, were done for 45 patients. During follow-up, newly developed lung cancers and/or malignancies in other organs were recorded. The average smoking index (cigarettes per day x years) was 1040. Synchronous and/or metachronous multiple lung cancers developed in 26/91 patients (28.6%). Malignancies in other organs were found in 12/91 (13.2%). The smoking index of patients with multiple lung cancers was significantly higher than for other patients. The overall 5 year survival rate was 70.7% in all patients, 76.0% in the surgery group, and 64.4% in the nonsurgery group. The lung cancer-specific 5 year survival rate was 89.8% in all patients, 89.3% in the surgery group, and 90.5% in the nonsurgery group. Early hilar lung cancer frequently accompanies other lung cancers or malignancies in other organs. A favorable prognosis can be obtained with organ-sparing treatment.

Comparison of in situ gelling formulations for the oral delivery of cimetidine

Three liquid formulations with in situ gelling properties have been assessed for their potential for the oral delivery of cimetidine. The formulations were dilute solutions of: (a) enzyme-degraded xyloglucan, which form thermally reversible gels on warming to body temperature; (b) gellan gum and; (c) sodium alginate both containing complexed calcium ions that form gels when these ions are released in the acidic environment of the stomach. The in vitro release of cimetidine from gels of each of the compounds followed root-time kinetics over a period of 6 h. Plasma levels of cimetidine after oral administration to rabbits of each of the formulations were compared with those resulting from administration of a commercial cimetidine/alginate suspension with an identical drug loading. In vivo release characteristics of each of the in situ gelling formulations were similar to those of the commercial preparation.

Isolation and characterization of the Schizosaccharomyces pombe cDNA encoding the mitochondrial endonuclease(1)

We isolated the cDNA of the fission yeast mitochondrial endonuclease SpNUC1, which consists of 322 amino acids and has a significant homology with the budding yeast NUC1 and mammalian endonuclease G. Comparison of the cDNA sequence with the genomic sequence showed that the gene consists of three exons and two introns and spans 1.31 kb. The enzyme localization in mitochondria was demonstrated by expressing the SpNUC1-green fluorescent protein fusion in the yeast. The endonuclease was activated by truncation of the amino-terminal region of the protein, indicating that the enzyme is encoded as an inactive precursor. The active enzyme degraded single-stranded DNA and RNA, the activity being dependent on Mg(2+) (Mn(2+)).

Endoscopic evaluation of centrally located early squamous cell carcinoma of the lung

BACKGROUND

Lung-sparing treatment recently has become a choice in the treatment of patients with early hilar lung carcinoma. To select the method of treatment, it is important to evaluate the histologic extent of the tumor using endoscopy.

METHODS

A total of 46 patients who underwent surgery for an endoscopically evaluated early lung carcinoma of the tracheobronchial tree were analyzed. Initial surgery was performed in 16 patients and in 30 patients surgery was performed after preoperative laser therapy. The endoscopic findings were classified into three types: superficial, nodular, and polypoid. In the resected lung, the greatest tumor dimension, the depth of mural invasion, the presence of microscopic blood and lymph vessel invasion, and metastases to the dissected lymph nodes were examined.

RESULTS

The mean greatest tumor dimensions were 14.6 +/- 7.3 mm (mean +/- standard deviation) in the nodular group, 23.3 +/- 12.8 mm in the superficial group, and 19.0 +/- 9.2 mm in the polypoid group. The greatest tumor dimension in the superficial group was significantly larger than that in the nodular group (P < 0.01). Preoperative endoscopic diagnosis of early hilar lung carcinoma was correct histologically in 34 of 46 cases (74.0%). Hilar lymph node metastases (N1), extrabronchial invasion, and extension to the peripheral bronchus were recognized in 12 cases. Complete disappearance of the tumor due to preoperative laser therapy was confirmed in eight patients. Lymph node metastasis was not found when the greatest tumor dimension measured < 8 mm. The overall absolute 5-year survival rate was 76.0% for all patients, 87.1% for the surgery alone group, and 70.0% for the surgery after preoperative laser therapy group.

CONCLUSIONS

Curative treatment of early hilar lung carcinoma is possible using photodynamic therapy alone when the tumor size is < or = 8 mm and the lesion does not extend to the peripheral bronchus.

Selective glycopeptide mapping of erythropoietin by on-line high-performance liquid chromatography--electrospray ionization mass spectrometry

Selective glycopeptide mapping of recombinant human erythropoietin (rhEPO) used as a model glycoprotein was successfully carried out by on-line high-performance liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS) using a Vydac C18 column eluted in acetonitrile-1 mM ammonium acetate, pH 6.8. rhEPO expressed in a Chinese hamster ovary clone was exhaustively digested into four glycopeptides and nine peptides with endoproteinase Glu-C. Both glycopeptides and peptides were eluted with trifluoroacetic acid as the eluent, whereas only glycopeptides were eluted selectively with ammonium acetate in the following order: N38, N24, 0126, and N83. Furthermore, many glycoforms included in each glycopeptide were found to be separated by differences in the numbers of sialic acid and N-acetyllactosaminyl repeats. Twenty, 16 and 22 different N-linked oligosaccharides were determined at Asn24, 38, and 83, respectively, and two different O-linked oligosaccharides were observed at Ser126. Our method is simple, rapid, and useful for determining the carbohydrate structures at each glycosylation site and for elucidating the site-specific carbohydrate heterogeneity.

Antioxidative and 5-lipoxygenase inhibiting activities of novel bis(4-hydroxy-2,3,5-trimethylphenoxy)alkyl derivatives

Novel bis(4-hydroxy-2,3,5-trimethylphenoxy)alkyl derivatives were synthesized and evaluations were made of their inhibiting action on Fe3+-ADP induced lipid peroxidation in rat liver microsome and reducing action on alpha,alpha-diphenyl-beta-picrilhydrazyl (DPPH), a stable radical, in addition to their inhibiting action on 5-lipoxygenase (5-LO), an enzyme that synthesizes leukotrienes. We performed a structure-activity correlation study on these derivatives. A strong Fe3+-ADP induced lipid peroxidation preventing activity was observed for the derivatives with an odd number of methylene groups including 1,3-bis(4-hydroxy-2,3,5-trimethylphenoxy)propane (3b) and 3a. No change in the DPPH reducing activity was found with change in the number of methylene groups. 5-LO inhibiting activity among the derivatives was the highest for 1,6-bis(4-hydroxy-2,3,5-trimethylphenoxy)hexane (3e). MM2 calculations were performed to find a stable steric structure for the derivatives, and 1,5-bis(4-hydroxy-2,3,5-trimethylphenoxy)pentane (3d) showed a strong activity in both antioxidative action and 5-LO inhibiting action.

Trihalomethane removal by activated carbon fiber

For the safety of drinking water, trihalomethanes are removed by adsorption onto activated carbon fiber from single-component solutions. The amounts adsorbed onto adsorbents with large surface area and/or pore volume were small. Stronger surface hydrophobicity of adsorbent was correlated with a larger amount of trihalomethanes adsorbed. A trihalomethane with bromine was adsorbed to a greater extent than that with chlorine. The differences in the amounts adsorbed among trihalomethanes can be explained by the polarity of trihalomethane molecules. The amount of trihalomethanes adsorbed was mainly dominated by the strength of hydrophobicity of activated carbon fibers.