Phase I/II study of divided-dose docetaxel, cisplatin and fluorouracil for patients with recurrent or metastatic squamous cell carcinoma of the esophagus

Squamous cell carcinoma of the esophagus (SCCE) has a poor prognosis compared with other gastrointestinal cancers. Many patients present with locoregional unresectable or metastatic disease at the time of diagnosis. For these patients with metastatic esophageal cancer, chemotherapy is generally indicated. The aim of this phase I/II study was to evaluate the efficacy and safety of the combined use of docetaxel, cisplatin (CDDP) and 5-fluorouracil (5-FU)(DCF) in patients with recurrent/metastatic SCCE. This study adopted divided doses of docetaxel and CDDP in order to reduce the toxicities of the treatment. The dose of docetaxel was escalated using the following protocol in the phase I stage: level 1, 30 mg/m2; level 2, 35 mg/m2 and level 3, 40 mg/m2, which was intravenously infused for 2 hours on days 1 and 8. CDDP was administered at a dose of 12 mg/m2 infused for 4 hours on days 1-5. The 5-FU was administered at a dose of 600 mg/m2 continuously infused from day 1 to 5. This regimen was repeated every 4 weeks. The study subjects were nine patients (phase I) and 48 patients (phase II). The recommended dose was determined as level 3 in phase I. In the phase II stage, the overall response rate was 62.5%, with a complete response rate of 12.5%. The median progression-free survival was 6 months, and the median overall survival was 13 months. Grade 3/4 toxicities of leukopenia, neutropenia and febrile neutropenia occurred in 64.6%, 68.8% and 14.6% of the patients, while grade 3/4 non-hematological toxicities were relatively rare. No treatment-related death was recorded. This modified DCF regimen with divided doses can be a tolerable and useful regimen of definitive chemotherapy for unresectable SCCE because of its high efficacy, although adequate care for severe neutropenia must be administered.

Modulation of motor cortex excitability by peripheral magnetic stimulation of different stimulus sites and frequencies

Peripheral stimulation is known to influence the state of cortical excitability. The purpose of this study is to investigate whether peripheral magnetic stimulation has similar effects on cortical excitability to transcranial magnetic stimulation (TMS). A magnetic stimulator with a flat figure-of-eight coil was used for both TMS, and peripheral magnetic stimulation applied to the bilateral forearms. TMS was performed on the left primary motor cortex to evaluate influence of the peripheral magnetic stimulation, and motor evoked potential (MEP) was measured from the right first dorsal interosseous. Peripheral magnetic stimulation was performed at a stimulus frequency of 1 Hz or 10 Hz, to the stimulus sites on the right and left supination of the forearm. The effects of peripheral magnetic stimulation were evaluated by comparing the mean MEP amplitude elicited by TMS before and after peripheral magnetic stimulation. We found that cortical excitability varied according to the stimulation site and frequency of the peripheral magnetic stimulation. The inhibition of cortical excitability was observed following 1 Hz peripheral magnetic stimulation over the right forearm (p<;0.001). In contrast, increased cortical excitability was observed using 1 Hz peripheral magnetic stimulation over the left forearm and 10 Hz stimulation over either the right or left forearms. We suggest that peripheral magnetic stimulation has a similar effect to TMS, and can induce both facilitation and inhibition of cortical excitability.

Randomized clinical trial comparing long-term quality of life for Billroth I versus Roux-en-Y reconstruction after distal gastrectomy for gastric cancer

BACKGROUND

Patients' quality of life (QoL) deteriorates remarkably after gastrectomy. Billroth I reconstruction following distal gastrectomy has the physiological advantage of allowing food to pass through the duodenum. It was hypothesized that Billroth I reconstruction would be superior to Roux-en-Y reconstruction in terms of long-term QoL after distal gastrectomy. This study compared two reconstructions in a multicentre prospective randomized clinical trial to identify the optimal reconstruction procedure.

METHODS

Between January 2009 and September 2010, patients who underwent gastrectomy for gastric cancer were randomized during surgery to Billroth I or Roux-en-Y reconstruction. The primary endpoint was assessment of QoL using the Functional Assessment of Cancer Therapy - Gastric (FACT-Ga) questionnaire 36 months after surgery.

RESULTS

A total of 122 patients were enrolled in the study, 60 to Billroth I and 62 to Roux-en-Y reconstruction. There were no differences between the two groups in terms of postoperative complications or mortality, and no significant differences in FACT-Ga total score (P = 0·496). Symptom scales such as epigastric fullness (heaviness), diarrhoea and fatigue were significantly better in the Billroth I group at 36 months after gastrectomy (heaviness, P = 0·040; diarrhoea, P = 0·046; fatigue, P = 0·029). The rate of weight loss in the third year was lower for patients in the Billroth I group (P = 0·046).

CONCLUSION

The choice of anastomotic reconstruction after distal gastrectomy resulted in no difference in long-term QoL in patients with gastric cancer.

REGISTRATION NUMBER

NCT01065688 (http://www.clinicaltrials.gov).

The impact of rTMS over the dorsolateral prefrontal cortex on cognitive processing

The purpose of the present study was to use event-related potentials (ERP) to clarify the effect of magnetic stimulation on cognitive processing. A figure eight-shaped flat repetitive transcranial magnetic stimulation (rTMS) coil was used to stimulate either the region over the left or the right dorsolateral prefrontal cortex, which is considered to be the origin of the P300 component. Stimulus frequencies were 1.00, 0.75 and 0.50 Hz rTMS. The strength of the magnetic stimulation was set at 80% of the motor threshold for each participant. The auditory oddball task was used to elicit P300s before and shortly after rTMS, and comprised a sequence of sounds containing standard (1 kHz pure tone, 80% of trials) and deviant (2 kHz pure tone, 20% of trials) stimuli. We found that a 1.00 Hz rTMS pulse train over the left dorsolateral prefrontal cortex increased P300 latencies by 8.50 ms at Fz, 12.85 ms at Cz, and 11.25 ms at Pz. In contrast, neither 0.75 and 0.50 Hz rTMS pulse trains over the left dorsolateral prefrontal cortex nor 1.00, 0.75 and 0.50 Hz rTMS pulse trains over the right dorsolateral prefrontal cortex altered P300 latencies. These results indicate that rTMS frequency affects cognitive processing. Thus, we suggest that the effects of rTMS vary according to the activity of excitatory and inhibitory neurons in the cerebral cortex.

Time-dependent effects of low-frequency repetitive transcranial magnetic stimulation of the supramarginal gyrus

In this paper, we report our studies of the effects of stimulating the bilateral supramarginal gyrus (SMG) with low-frequency transcranial magnetic stimulation (rTMS) or short-term rTMS on brain excitability in humans. We analyzed the effects of various durations of stimulation on P300 latencies of the event-related potential (ERP). Magnetic pulses were delivered using a figure-eight flat coil. The intensity of rTMS was set to 80 % of the subject's motor threshold. In each round of rTMS, 100 magnetic pulses were applied over the scalp at frequencies of 1.00, 0.75, and 0.50 Hz. ERPs were measured prior to magnetic stimulation as a control. The effects of magnetic stimulation were then determined by measuring its effects on P300 latencies elicited by an odd-ball task. These latencies were measured before and 0, 5, 10, and 15 min after the magnetic stimulation. 1.00 Hz low-frequency rTMS of the left SMG decreased P300 latencies for approximately 10 min. In contrast, 0.50 Hz rTMS of the left SMG resulted in delayed P300 latencies for approximately 15 min. We furthermore found that 0.75 Hz rTMS of the left SMG and 1.00, 0.75 and 0.5 Hz rTMS of the right SMG did not affect P300 latencies. These results suggest that the duration of the effects of rTMS depend on the frequency of stimulation.

Effect of transcranial magnetic stimulation on P300 of event-related potential

When the odd stimulation is presented, the positive component of electroencephalograph is induced at around 300 ms after the odd stimulation. This positive component is called P300. Many studies suggest that P300 may result from the summation of activity from multiple generators located in widespread cortical and subcortical areas. However, there is still no conclusive indication of the sources of P300. In this paper, we focus on the left supramaginal gyrus as one of the sources of P300. We investigated the temporal aspect of this area using TMS (transcranial magnetic stimulation). We investigated the relationship between the latency of the P300 and an effect of TMS when the left supramarginal gyrus was stimulated by TMS. In our previous study, we reported a method of removing stimulus artifact during TMS with Sample-and-Hold circuit and electroencephalogram (EEG) activity evoked by TMS could be measured successfully. In addition to this method, independent component analysis (ICA) was also applied to recorded EEG data in order to remove the stimulus artifact by off-line analysis. By using these methods, short latency (< 15 ms) EEG responses to TMS could be obtained. We stimulated the left supramarginal gyrus using a figure-eight coil during auditory oddball task. The TMS at 150 ms and 200 ms after the oddball sounds were presented. When the TMS was applied at 200 ms after the oddball stimulation, the peak response of P300 was delayed around 50 ms. Difference of the peak latency between the control measurement and the case of TMS applying at 150 ms was not significant. However, the differences of the peak latency of the control measurement and the peak latency of the measurement in the cases of TMS applying at 200 ms and 250 ms was significant (p<0.05). We considered that this delay was due to inhibiting to recognize the target stimulation.

Differences in evoked EEG by transcranial magnetic stimulation at various stimulus points on the head

The combination of transcranial magnetic stimulation (TMS) and electroencephalogram (EEG) is an effective tool for investigating the cortical reactivity and the functional connectivity in the brain. In our previous study, we reported a method of removing stimulus artifact during TMS with Sample-and-Hold circuit and EEG activity evoked by TMS could be measured successfully. In addition to this method, independent component analysis (ICA) was also applied to recorded EEG data in order to remove the stimulus artifact from for off-line analysis. By using these methods, short latency ( 15 ms) EEG responses to TMS could be obtained. In this paper, we focused on the propagation of EEG activity elicited by TMS. We observed both the EEG topography and the distribution of the current density over the whole head by changing the stimulus site. When motor cortex was stimulated, the propagation of EEG activity to contralateral hemisphere could be clearly observed. However, when posterior parietal cortex was stimulated, no or less propagation of EEG responses could be recognized. These results suggest that the responses evoked by TMS over motor cortex propagate to contralateral hemisphere along the axon through the corpus callosum.

[Effects of octreotide acetate on intractable chylothorax after surgery for congenital heart diseases]

We experienced 2 infants in whom octreotide acetate was effective on intractable chylothorax after surgery for congenital heart diseases. They were 8- and 5-month-old. They were diagnosed as having corrected transposition of the great arteries (TGA) and tetralogy of Fallot respectively, and underwent bidirectional Glenn anastomosis and right modified Blalock Taussig shunt. Chylothorax was revealed on the 11th and the 1st postoperative day, and was not improved by any conventional therapy in either case. Then octreotide acetate was infused continuously with 0.1-0.6 micorg/kg/hour for 24 and 7 days. Chylothorax disappeared completely without any complications such as disturbance of blood sugar level or growth retardation. Octreotide acetate was effective and safe even in infants in intractable chylothorax after surgery for congenital heart diseases, as long as used for short period.

[Effects of additional pulmonary blood flow after bidirectional Glenn procedure]

Thirteen cases of functional single ventricle who had undergone bidirectional Glenn procedure were divided into 2 groups according to presence (5) or absence (8) of additional pulmonary blood flow. Additional flow was preserved in cases with relatively small pulmonary artery index (PA index), and their sources were antegrade pulmonary blood flow (2), and Blalock-Taussig (BT) shunt (3). In the control group, PA index was reduced to about 70% of the preoperative value, while in the additional group, pulmonary artery growth was recognized without significant elevation of mean pulmonary artery pressure. However, atrioventricular valve regurgitation progressed and systemic ventricular volume did not decrease after Glenn in the additional group. Therefore special consideration for the timing of Fontan procedure is mandatory.

[Evaluation of aortic valve replacement involving small severely calcified aortic annulus in elderly patients]

We performed aortic valve replacement in 24 patients aged over 70 with small calcified valves. The surgical management of such patients remains controversial as the extensive calcification compromises implantation. Hence, we used an ultrasonic debridement instrument to remove calcium and selected a small prosthesis with the largest possible orifice without enlargement of the aortic annulus. Echocardiography showed significant reductions in left ventricular mass index compared with preoperative values. Early and mid-term prognosis has been relatively good.

Specific T-cell immunity against Ki-ras peptides in patients with pancreatic and colorectal cancers

Mutations of codon 12 in the Ki-ras gene are frequently found in pancreatic and colorectal cancers. It has been demonstrated that human T-cells have the potential to recognise tumours expressing mutated ras-derived peptides. However, it remains unclear whether T-cells from a given individual can recognise the mutant peptides, which are expressed in that individual's tumour tissues. Mutations of the Ki-ras oncogene were analysed by the mutant-allele-specific amplification (MASA) method in pancreatic and colorectal tumour tissues, and T-cell responses against mutated Ki-ras-derived peptides were measured by [(3)H]thymidine incorporation and IFN-gamma production assays. Specific T-cell responses against Ki-ras-products were found in cancer patients, whereas no immune response was observed in normal individuals (P<0.01). Six of the eight pancreatic cancer patients (75%) and nine of 26 colorectal cancer patients (35%) had T-cell responses to mutated Ki-ras-derived-peptides. T-cell response in a given individual cannot recognise the same mutated ras peptide, which is expressed in that individual's tumour tissues. However, pancreatic and colorectal cancer patients have T-cell immunity against Ki-ras-peptides, and this provides potential target for cancer immunotherapy.

Overexpression of pyrimidine nucleoside phosphorylase enhances the sensitivity to 5'-deoxy-5-fluorouridine in tumour cells in vitro and in vivo

5-Fluorouracil (5-FU) and 5'-deoxy-5-fluorouridine (5'-DFUR), a prodrug of 5-FU, are representative of the chemotherapeutic agents for colorectal adenocarcinomas. Pyrimidine nucleoside phosphorylase (PyNPase) catalyses the conversion of 5'-DFUR to 5-FU, the activated form. Murine adenocarcinoma CT26 cells were transfected with human PyNPase cDNA. The engineered transfectants producing PyNPase augmented the response to 5'-DFUR in vitro and in vivo. Animals were administered by means of intraperitoneal (i.p.) injection, and not orally, in order to obtain a better efficiency of absorption. The tumours of the transfected cells nearly all disappeared, even following treatment with quite a small amount of the anticancer agent. The animals injected with the tranfected cells were protected against subsequent challenge with the parental tumour cell line. These findings demonstrate that PyNPase gene transfection increases the sensitivity to 5'-DFUR, and thereby decreases the toxicity of the agent.

Intelligent yeast strains with the ability to self-monitor the concentrations of intra- and extracellular phosphate or ammonium ion by emission of fluorescence from the cell surface

Saccharomyces cerevisiae strains that respond to environmental changes and transmit the information by emission of fluorescence from the cell surface were constructed. The technique of cell surface engineering enabled the yeast cells to display enhanced cyan blue fluorescent protein (ECFP) or enhanced yellow fluorescent protein (EYFP) on the surface under the control of promoters that sense environmental changes. Two model promoters were examined in this study. For monitoring the intra- and extracellular concentrations of phosphate ion, the PHO5 promoter was chosen to display ECFP. The MEP2 promoter was used to display EYFP to sense the concentrations of ammonium ion. Fluorescence was observed by fluorescence microscopy and immunofluorescence microscopy, and the intensity was measured by a flow cytometer. The relationship between ion concentration inside and outside the cells was evaluated by the change in the rate of fluorescence. This S. cerevisiae system enables environmental changes to be transmitted as intra- and extracellular information using a suitable promoter functioning at real time and in a non-invasive manner.

NADH dehydrogenase of Corynebacterium glutamicum. Purification of an NADH dehydrogenase II homolog able to oxidize NADPH

NADPH oxidase activity, in addition to NADH oxidase activity, has been shown to be present in the respiratory chain of Corynebacterium glutamicum. In this study, we tried to purify NADPH oxidase and NADH dehydrogenase activities from the membranes of C. glutamicum. Both the enzyme activities were simultaneously purified in the same fraction, and the purified enzyme was shown to be a single polypeptide of 55 kDa. The N-terminal sequence of the enzyme was consistent with the sequence deduced from the NADH dehydrogenase gene of C. glutamicum, which has been sequenced and shown to be a homolog of NADH dehydrogenase II. In addition to high NADH-ubiquinone-1 oxidoreductase activity at neutral pH, the purified enzyme showed relatively high NADPH oxidase and NADPH-ubiquinone-1 oxidoreductase activities at acidic pH. Thus, NADH dehydrogenase of C. glutamicum was shown to be rather unique in having a relatively high reactivity toward NADPH.

Effect of peroxisome proliferator-activated receptor alpha activation on leukotriene B4 metabolism in isolated rat hepatocytes

Leukotriene B4 (LTB4) is a potent mediator of inflammation that recruits granulocytes to the site of injury during the inflammatory response. The biological activity of LTB4 is terminated by its metabolism into inactive metabolites. Recent studies have suggested that LTB4 may have additional activity as an endogenous ligand for the transcription factor peroxisome proliferator-activated receptor alpha (PPARalpha). Based on the data presented, a model was proposed in which LTB4 acts in a negative feedback manner by inducing the transcription of genes involved its own metabolism. In the present study the effect of PPARalpha activation on LTB4 metabolism was directly investigated. Primary cultures of rat hepatocytes were treated with LTB4 or the PPARalpha agonist WY-14,643, and LTB4 metabolism was assessed by measuring levels of LTB4 and the formation of LTB4 metabolites. In addition, the effect of PPARalpha activation on levels of acyl-CoA oxidase mRNA and expression of CYP4F proteins, which are specific omega-hydroxylases for LTB4, was determined. Treatment of hepatocytes with WY-14,643, but not LTB4, was found to increase acyl-CoA oxidase mRNA and enhance expression of rat hepatic CYP4F proteins and CYP4A1. Neither WY-14,643 nor LTB4 caused an increase of the basal levels of LTB4 metabolism, and no novel metabolites were observed. These results do not support the hypothesis that a pathway of negative feedback regulation of LTB4 metabolism involving PPARalpha exists in hepatocytes, because activation of PPARalpha by LTB4 or other PPARalpha agonists did not correlate with an increase in LTB4 metabolism.

Stereocontrolled total synthesis of the Stemona alkaloid (-)-stenine

The Stemona alkaloid stenine (1), isolated from Stemona tuberosa of physiologically active stemonaceous plants, possesses the structurally novel and unique azepinoindole skeleton (B,C,D-ring system). We have achieved the asymmetric total synthesis of (-)-stenine (1), starting from 1,5-pentanediol (10). The key features are an intramolecular diastereoselective Diels-Alder reaction of the (E,E,E) triene 6, prepared in a convergent fashion from three components--dienyl chloride 7, dithiane 8, and chiral phosphonate 9--and efficient construction of the tricyclic A,B,D-ring system 29 through thermodynamically controlled regioselective enolization of the bicyclic ketone 25. In this article, we describe in detail the highly stereocontrolled total synthesis of (-)-stenine (1). These results should be useful for the asymmetric total synthesis of another, more complex. molecule: tuberostemonine (2), the synthesis of which has never been reported.

Effects of nicotine on the intervertebral disc: an experimental study in rabbits

Clinically, we have observed that a large proportion of patients presenting with low back pain as the chief complaint are smokers. It was therefore postulated that smoking might affect the intervertebral disc. We investigated the histological and functional effects of nicotine on intervertebral discs in rabbits. Rabbits were implanted subcutaneously with minipumps for the delivery of 200 microg/ml nicotine for 4 or 8 weeks. The selected dose produced blood nicotine levels equivalent to those found in heavy smokers (30 cigarettes/day). Nicotine injection caused necrosis and fibrous tissue and vitreous formation in the nucleus pulposus of the intervertebral disc, as well as hypertrophy of the fibrous ring, with partial cracks and detachment. Measurement of collagen and proteoglycan production in intervertebral discs showed reduced synthesis of these proteins in nicotine-treated rabbits compared with the control findings. Our results indicated that the harmful effects of nicotine on the integrity of the intervertebral disc might be mediated by the direct effect of nicotine, or indirectly, by causing vasoconstriction of the vascular network surrounding the intervertebral discs.

Complete response of highly advanced gastric cancer with peritoneal dissemination after new combined chemotherapy of S-1 and low-dose cisplatin: report of a case

TS-1(S-1) has been developed as a new oral anticancer drug based on the biological modulation of 5-fluorouracil. We treated a patient with highly advanced gastric carcinoma with a new combination chemotherapy of S-1 and low-dose cisplatin. Remarkable tumor reduction was observed after two cycles of this therapy in the primary tumor and metastatic lymph nodes, and the ascites disappeared. This was concluded to be a partial response. The only adverse effect was skin pigmentation of the fingers (grade 1), leading to early timing of operation after chemotherapy. The gastric tumor showed evident invasion to the serosa. Lymph nodes around the stomach were swollen. Peritoneal dissemination was also recognized in the omentum and mesocolon. Total gastrectomy with regional lymph node dissection was performed. Disseminated tumors were all resected. Histological examination showed that no tumor cells were detected in the gastric primary lesion, metastatic lymph nodes or disseminated peritoneal tumors, suggesting pathological complete remission. It was suggested that this regimen could be a potent combined therapy for the treatment of patients with highly advanced gastric carcinoma, and it could be useful as neoadjuvant chemotherapy. Further studies are necessary to evaluate the efficacy of this therapy.

Carcinoembryonic antigen-specific suicide gene therapy of cytosine deaminase/5-fluorocytosine enhanced by the cre/loxP system in the orthotopic gastric carcinoma model

Tumor-specific gene delivery is crucial to achieving successful effects in suicide gene therapy. Carcinoembryonic antigen (CEA) promoter has been widely used for this purpose, but the expression level of tumor-specific promoters such as CEA promoter is generally low. In the previous study, we used the Cre/loxP system and showed that LacZ expression by the CEA promoter was remarkably enhanced and maintained its specificity using the Cre/loxP regulation system. In this study, the Cre/loxP system was first applied to augmentation of selective expression of the cytosine deaminase (CD) gene as a suicide gene therapy in CEA-producing cells. The double infection with AxCEANCre expressing Cre recombinase under the control of the CEA promoter and AxCALNLCD expressing the CD gene under the control of the CAG promoter by the Cre switching system rendered CEA-producing tumor cells 13-fold more sensitive to 5-fluorocytosine (5-FC) compared with the single infection with AxCEACD expressing CD gene driven by the CEA promoter. The therapeutic efficacy of the enhanced CD/5-FC suicide gene therapy was evaluated in orthotopic implantation models of human gastric carcinoma. Adenovirus vectors (1 x 10(9) plaque-forming units) were administered i.p. into mice three times, and then 5-FC was administered i.p. for the next 10 days. Tumor volume and weight in mice treated with AxCEANCre and AxCALNLCD/5-FC were significantly reduced as compared with those in mice treated not only with Mock (AxCALacZ) but also with AxCEACD/5-FC (P < 0.0001). This beneficial effect on tumor burden was also reflected in the overall survival. The survival periods of the mice treated with AxCEANCre and AxCALNLCD/5-FC were longer than those of mice treated with Mock or AxCEACD/5-FC (P < 0.01). These results suggested that application of the Cre/loxP system could provide a new approach for enhanced selective suicide gene therapy of CD/5-FC for the treatment of advanced gastric carcinoma.

Decreased type III and V collagen expression in chorionic villi of hydatidiform mole

To investigate the characteristic structure of hydatidiform mole, various types of collagen expression were determined in human villous tissues obtained from normal pregnancies (n = 17) and complete hydatidiform moles (n = 10). Indirect immunofluorescent staining was performed to detect type I, III, and VI collagen with specific monoclonal antibodies. Collagens were also extracted from the villous tissues obtained from normal pregnancy and hydatidiform mole by the salt precipitation method. Immunohistochemical staining for type I, III, and VI collagen revealed weak staining of the villous stroma in hydatidiform mole compared with that in normal pregnancy. Both the ratios of type III to type I collagen and the ratios of type V to type I collagen in the villous tissues were significantly decreased (P < 0.05) in molar pregnancy compared with those in normal pregnancy. These results suggest that alterations in the distribution and composition of collagen might play an important role in determining the pathophysiology and structure of hydatidiform mole.

Overexpression of type IV collagen in chorionic villi in hydatidiform mole

To investigate the characteristic structure of hydatidiform mole, type IV collagen expression was determined in human villous tissues obtained from normal pregnancies (n = 17) and complete hydatidiform moles (n = 10). Indirect immunofluorescent staining was performed to detect type IV collagen with specific monoclonal antibody, and Northern blot analysis was performed to assess expression of messenger ribonucleic acid for the alpha1(IV) chain. In addition, serum levels of type I, III, and IV collagen were measured by RIA. Immunohistochemical staining for type IV collagen revealed stronger staining of the trophoblastic basement membrane in hydatidiform mole than in normal pregnancy. Northern blot analysis revealed that the villous expression of messenger ribonucleic acid for the alpha1(IV) chain was significantly increased in hydatidiform moles compared with normal pregnancy (P < 0.01). Although there were no differences in the serum type I and III collagen levels between hydatidiform mole and normal pregnancy, the type IV collagen level was significantly higher in patients with hydatidiform mole than in normal pregnancy (P < 0.05). These results suggest that type IV collagen might play an important role in determining the pathophysiology and structure of hydatidiform mole.

Development of a minimally immunogenic variant of humanized anti-carcinoma monoclonal antibody CC49

Monoclonal antibody (MAb) CC49 reacts with a pancarcinoma antigen, tumor associated glycoprotein (TAG)-72. To circumvent human anti-murine antibody (HAMA) responses in patients, we earlier developed a humanized CC49 (HuCC49) by grafting the complementarity-determining regions (CDRs) of MAb CC49 onto variable light (VL) and variable heavy (VH) frameworks of the human MAbs LEN and 21/28'CL, respectively. With the aim of minimizing its immunogenicity further, we have now generated a variant HuCC49 MAb by grafting the specificity-determining residues (SDRs) of MAb CC49 onto the frameworks of the human MAbs. Based on the evaluation of its binding affinity for TAG-72 and its reactivity with anti-idiotypic antibodies present in sera from patients who have been treated with murine CC49, this variant retains its antigen-binding activity and shows minimal reactivity with anti-idiotypic antibodies in patients' sera. Development of this variant, which is a potentially useful clinical reagent for diagnosis and therapy of human carcinomas, demonstrates that for humanization of a xenogeneic antibody grafting of the potential SDRs should be sufficient to retain its antigen-binding properties.

A patient with severe palindromic rheumatism and frequent episodes of pain

A 44-year-old man began to experience episodes of joint pain with erythema in his knees, elbows, shoulders, and hands in April 1996. He was diagnosed as having palindromic rheumatism. Due to the increasing frequency and severity of these episodes, he was admitted to our hospital in May 1999. Heat therapy to the affected area produced a rapid improvement in symptoms. In addition, the continued use of physical therapy during symptom-free periods tended to reduce the frequency and severity of pain attacks. We present this case and discuss treatment options in patients with palindromic rheumatism.

Allogeneic bone marrow transplantation-related transmission of human T lymphotropic virus type I (HTLV-I)

We report here the first case report of bone marrow transplantation (BMT)-related transmission of human T lymphotropic virus type-I (HTLV-I). Antibodies against HTLV-I-associated antigens (anti-HTLV-I) were detected in the serum from the BMT recipient 12 days post BMT. IgG against gag core proteins (anti-p19 and anti-p24) appeared earlier than IgM against gag and env proteins (anti-p19, anti-p24 and anti-gp46) during seroconversion. The data presented here differs from blood transfusion-related seroconversion. This phenomenon may be due to the engraftment of anti-HTLV-I producing cells from the donor.

[New therapeutic strategy against colon cancer based on a tumor-specific approach]

To develop a new therapy against colon cancer, we investigated two kinds of strategy using a cancer-specific approach. First, we employed the Cre/loxP regulation system to enhance the specific expression by carcinoembryonic antigen (CEA) promotor in CEA-producing tumor cells, and examined whether sufficient enhancement to transcriptional activity of CEA promotor, which maintains its specificity in vitro and in vivo, could be obtained. Next, using dendritic cells pulsed with HLA-A24 epitope peptides of CEA, we performed a Phase I study of active immunotherapy in patients with advanced colon cancer. These results suggest that the newly developed therapy for colon cancer is a promising strategy; however, minor modification may be necessary.

Prediction of functional outcome after stroke rehabilitation

OBJECTIVE

The purpose of this study is to identify predictors of functional outcome after acute stroke inpatient rehabilitation using raw Functional Independence Measure (FIM) total scores.

DESIGN

Multivariate analysis was performed on data collected retrospectively from stroke rehabilitation patients. Six independent variables were obtained from patients' medical records.

RESULTS

The FIM total scores at the time of discharge from the hospital correlated strongly with FIM total scores at the time of admission to the hospital and correlated negatively with age and OAI using the Spearman's rank correlation method. The FIM total scores at the time of hospital admission were the best predictor of FIM total scores at the time of discharge from the hospital. However, the nature of the stroke, gender, and LOHS did not correlate with FIM total scores at the time of discharge from the hospital.

CONCLUSIONS

Because FIM total scores at the time of hospital admission and discharge are highly correlated, FIM total scores at the time of hospital admission can be used to establish a rehabilitation program, to inform the patient and family about the possibility of recovery, and to assess the amount and quality of care given in the home or discharge placement.

Autologous blood donation with recombinant human erythropoietin for abdominal aortic aneurysm surgery

We evaluated the efficacy of autologous blood donation using recombinant human erythropoietin for elective abdominal aortic aneurysm (AAA) surgery regarding postoperative recovery. Twenty-five AAA patients who completed surgery without receiving a homologous blood transfusion were divided into two groups, consisting of a control group (n = 12) who did not bank any autologous blood, and a donation group (n = 13) who did bank more than 800 ml of autologous blood with the use of erythropoietin. The hematocrit (Ht) level of the control group decreased from 41.1% +/- 1.2% before the operation to 36.2% +/- 0.9% just afterwards (P > 0.01). In the donation group, however, the Ht did not change significantly during either the donation period or the perioperative period. The postoperative period before oral food intake and natural defecation were both significantly shorter in the donation group than in the control group. The first day of mobilization was also earlier in the donation group. In conclusion, autologous blood donation using erythropoietin for AAA surgery is therefore considered to promote the early recovery of patients.

Structural and functional characterization of liver cell-specific activity of the human sodium/taurocholate cotransporter

Bile salts are rapidly removed from the circulation by the liver-specific sodium/taurocholate cotransporter (SLC10A1). To understand factors controlling its liver-specific expression, we isolated human SLC10A1 from a YAC chromosomal clone. SLC10A1 spans approximately 23 kb distributed over five exons. The major transcription start site is at 299 bp, and a minor start site is at 395 bp from the translational start site. A 1.2-kb portion of the 5' flanking region was sequenced and shown to contain a number of liver-enriched elements, but no TATA box. Using secreted alkaline phosphatase reporter constructs liver-specific expression was examined. Transient transfection demonstrated that SLC10A1 promoter expression was selectively expressed eightfold in FAO and rat hepatocytes, while deletion mutants demonstrated liver-specific expression in a region extending from -5 to +198 bp, which contained putative sites for C/EBP and HNF3. Mutations of the C/EBP site resulted in loss of 77% of transcriptional activity. Cotransfection of C/EBP, but not other putative liver-enriched binding factors, increased SLC10A1 promoter activity. Electrophoretic mobility shift assays demonstrated specific protein-DNA interactions that involved C/EBPalpha and beta. These studies demonstrate that the TATA-less human SLC10A1 promoter exhibits liver-specific activity and its regulatory elements contain binding sites for C/EBP, which contributes specifically to its transcriptional regulation.

Enhanced selective gene expression by adenovirus vector using Cre/loxP regulation system for human carcinoembryonic antigen-producing carcinoma

Selective gene targeting using the carcinoembryonic antigen (CEA) promoter is useful in gene therapy for gastrointestinal cancer. However, the expression of the CEA promoter is not sufficient. In this study, we tried to enhance CEA promoter activity using the Cre/loxP system. The double infection of CEA-producing cells such as MKN45 and LoVo with AxCEANCre and AxCALNLZ at a total multiplicity of infection (MOI) of 50 achieved 7-fold higher expression level of beta-galactosidase activity than single infection of those cells with AxCEALacZ at 50 MOI. On the other hand, the double infection of CEA-nonproducing cells such as MKN1 and HeLa cells showed a very low expression of beta-galactosidase activity. In the subcutaneous tumor models, the administration of AxCEANCre and AxCALNLZ into the CEA-producing tumor showed stronger expression of the LacZ gene in tumor tissue than that of AxCEALacZ. In the experiment using orthotopic models of CEA-producing gastric cancer, intraperitoneal double administration of AxCEANCre and AxCALNLZ caused evident LacZ gene expression in transplanted gastric tumors, but no LacZ gene expression in the normal stomach or liver. It was confirmed that enhanced tissue-specific gene transduction under control of CEA promoter using the Cre/loxP system was useful not only in vitro, but also in vivo, especially in orthotopic models.

Type VI collagen expression during growth of human ovarian follicles

OBJECTIVE

To identify type VI collagen expression in human ovarian follicles during follicular growth.

DESIGN

In vitro experiment.

SETTING

Department of Obstetrics and Gynecology, Wakayama Medical College, Japan.

PATIENT(S)

Regularly cycling women who underwent adnexectomy.

INTERVENTION(S)

Immunohistochemistry and in situ hybridization for human type VI collagen.

MAIN OUTCOME MEASURE(S)

Expression of type VI collagen.

RESULT(S)

Expression of type VI collagen was observed in the theca cell layers during folliculogenesis, whereas no expression of type VI collagen was observed in the granulosa cell layers at the mRNA and protein levels. As the follicles grew, immunostaining for type VI collagen became intense in the theca cell layers, especially the theca externa. In preovulatory follicles, however, weak, fragmented, or discontinuous immunostaining of the theca cell layers was observed. This fragmented or discontinuous immunostaining was evident predominantly in the apical area of preovulatory follicles rather than in the basal area.

CONCLUSION(S)

Type VI collagen is present in the theca cell layers of follicles during folliculogenesis and plays an important role in interactions between the theca cells and extracellular matrix. These interactions may lead to changes in the shape, proliferation, migration, or differentiation of follicular cells during follicular development, maturation, and ovulation.

Primary effusion lymphoma with B-cell phenotype

We describe here a case of primary effusion lymphoma that occurred in a 78-year-old woman. She was successively treated with prednisolone but died 15 months after the diagnosis of primary effusion lymphoma. The immunohistochemistry revealed the neoplastic cells to be CD19(+), CD20(+), CD21(+), Sm-Ig(+), and HLA-DR(+). This patient exhibited clonal IgH and clonal kappa light chain gene rearrangement, indicating a B-cell origin. The present case was distinguished from the majority cases of HHV-8-positive primary effusion lymphoma. Here we present clinical details of response to therapy in this case.

A struma ovarii with increased serum basement membrane components: a case report

We report a case of struma ovarii with hyperthyroidism and elevated serum concentrations of type IV collagen and laminin. Circulating levels of type IV collagen and laminin were measured using specific radioimmunoassays (RIAs) for 7S collagen and the P-1 fragment of laminin, and the basement membrane components in the tumor were investigated by immunohistochemical analysis. Strong immunohistochemical staining specific for type IV collagen and for laminin was observed to be localized in the follicular walls. The serum levels of these antigens, as determined by RIA, were very high before removal of the tumor but decreased rapidly postoperatively. The present findings suggest that struma ovarii produces large amounts of type IV collagen and laminin. In addition, elevated levels of thyroid hormones might enhance the turnover of the basement membrane in various tissues.

Structural correlates of an anticarcinoma antibody: identification of specificity-determining residues (SDRs) and development of a minimally immunogenic antibody variant by retention of SDRs only

Clinical utility of murine mAbs is limited because many elicit Abs to murine Ig constant and variable regions in patients. An Ab humanized by the current procedure of grafting all the complementarity determining regions (CDRs) of a murine Ab onto the human Ab frameworks is likely to be less immunogenic, except that its murine CDRs could still evoke an anti-variable region response. Previous studies with anticarcinoma mAb CC49 showed that light chain LCDR1 and LCDR2 of humanized CC49 could be replaced with the corresponding CDRs of a human Ab with minimal loss of Ag-binding activity. The studies reported in this paper were undertaken to dissect the CC49 Ag-binding site to identify 1) specificity determining residues (SDRs), the residues of the hypervariable region that are most critical in Ag-Ab interaction, and 2) those residues that contribute to the idiotopes that are potential targets of patients' immune responses. A panel of variants generated by genetic manipulation of the murine CC49 hypervariable regions were evaluated for their relative Ag-binding affinity and reactivity to sera from several patients who had been immunized with murine CC49. One variant, designated HuCC49V10, retained only the SDRs of CC49 and does not react with the anti-variable region Abs of the sera from the murine CC49-treated patients. These studies thus demonstrate that the genetic manipulation of Ab variable regions can be accomplished by grafting only the SDRs of a xenogeneic Ab onto human Ab frameworks. This approach may reduce the immunogenicity of Abs to a minimum.

Neutrophil functions and cytokine production in patients with gastric cancer

BACKGROUND/AIMS

One of the most important factors in the prevention of postoperative infection is the patient's own capacity to protect against infection. Neutrophils play a major role in this protection through phagocytosis and superoxide generation. Inflammatory cytokines are suitable for estimating the degree of surgical stress. The present study was designed to elucidate whether neutrophil functions are impaired in gastric cancer patients, and are related with cytokine production after surgery.

METHODOLOGY

Phagocytosis and superoxide generation by neutrophils was studied in 84 patients with gastric cancer by flow cytometry. IL-6, IL-8 and tumor necrosis factor alpha were studied in 18 patients with gastric cancer by enzyme-linked immunosolubent assay.

RESULTS

In gastric cancer patients phagocytosis was not impaired, whereas superoxide generation was lower than benign diseases and it was inhibited relative to the clinical stage. Moreover, superoxide generation was correlated with the nutritional parameters and was more suppressed in 7 patients who suffered from postoperative infection than in 40 patients whose postoperative course were uneventful. The fluctuation of superoxide generation correlated well with the serum cytokine levels in the postoperative course and its correlation was clarified in vitro. Nine patients with gastric cancer received intravenous hyperalimentation, and their superoxide generation was increased.

CONCLUSIONS

Superoxide generation by neutrophils was suppressed in gastric cancer patients and it is suggested that nutritional support prevents postoperative infection via the augmentation of superoxide generation.

In vitro augmentation of antitumor effect in combination with CPT-11 and CDDP for human colorectal cancer

BACKGROUND AND OBJECTIVES

Irinotecan hydrochloride (CPT-11) is one of the camptothecin analogues that has shown a broad spectrum of strong antitumor effectiveness against various cancers, including colorectal cancer. In order to promote the clinical response of chemotherapy for colorectal cancer using CPT-11, one of the most effective strategies is to use it in combination with other anticancer agents. In the present study, anticancer effects after combining CPT-11 and other antitumor agents were determined by a 3-(4,5-di-methylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay of colorectal cancer cells, especially freshly isolated cancer cells.

METHODS

Freshly isolated cancer cells from 20 patients with colorectal cancer and the established colon cancer cell lines were used in this study. The augmentation of the antitumor effectiveness of 7-ethyl-10-hydroxy-CPT (SN-38) was analyzed in combination with other anticancer agents. Furthermore, the antitumor effectiveness using lower concentrations of anticancer agents was measured to understand the mechanism of the augmentation.

RESULTS

The percent inhibition of SN-38 in combination with cisplatin (CDDP) and mitomycin revealed a high anticancer effect compared with each anticancer agent alone for freshly isolated rectal cancer. CDDP also had a synergistic effect in combination with SN-38 according to the fractional product concept. At lower than plasma peak concentrations of SN-38, the anticancer effects were augmented in combination with lower concentrations of CDDP for freshly isolated colorectal cancer. This augmentation showed a strong synergistic effect.

CONCLUSIONS

These results may be supportive to ongoing clinical studies of chemotherapy by using CPT-11 and CDDP for advanced colorectal cancer.

In vitro antitumor effect of topoisomerase-I inhibitor, CPT-11, on freshly isolated human gastric and colorectal cancer

CPT-11 is a comptothecin analogue which has shown a broad spectrum of strong antitumor effect against various cancers, including gastroenterological malignancies. In the present study, the antitumor effect of CPT-11 was determined by MTT assay for freshly isolated human gastric and colorectal cancer cells, especially highly purified tumor cells. Twenty-three patients with gastric cancer, and 32 patients with colorectal cancer were enrolled in this study. Three gastric and 3 colonic cancer cell lines were used to study the antitumor effect of CPT-11, and freshly isolated cancer cells from 3 patients with gastric cancer were investigated. The in vitro antitumor effect was tested by MTT assay, and showed % inhibition rate. CPT-11 and SN-38 showed the antitumor effect as a dose dependent matter for human gastric and colorectal tumor cells in vitro. From the results of chemosensitivity for freshly isolated gastric and colorectal tumor cells, antitumor effect of SN-38 was as strong as other conventional anticancer agents. It was demonstrated that the MTT assay was appropriate for the analysis of the antitumor effects of CPT-11 and SN-38, and that CPT-11 may be a worthwhile choice as an anticancer agent against gastric and colorectal cancer.

Fasting insulin and leptin serum levels are associated with systolic blood pressure independent of percentage body fat and body mass index

OBJECTIVE

To examine the relationship between leptin and insulin serum levels and systolic and diastolic blood pressure in young men.

SETTING

Kobe University of Mercantile Marine, Kobe, Japan.

PARTICIPANTS

One hundred and ninety-eight male students aged 18-20 years (comprising 100% of those eligible).

DESIGN AND MEASUREMENTS

A cross-sectional survey of a sample of male college students was performed, with measurements to include anthropometry, blood pressure and blood tests after overnight fasting.

RESULTS

Compared with 90 men with an optimal blood pressure, 56 men with high-normal and high blood pressure had an increase in body mass index (23.7 +/- 5.2 versus 20.4 +/- 2.2 kg/m2), percentage body fat (21.7 +/- 8.0 versus 16.3 +/- 4.2%) and serum leptin (3.7 +/- 4.7 versus 1.5 +/- 0.8 ng/ml). In addition, they had greater serum insulin (59 +/- 31 versus 43 +/- 12 pmol/l) despite there being no differences in plasma glucose, resulting in a reduction of the ratio of glucose to insulin (x 10(6)) (107 +/- 43 versus 126 +/-, which is an estimate of insulin sensitivity in a nondiabetic population. Furthermore, the 56 men had higher serum triglyceride levels, although there was no difference in low density lipoprotein-cholesterol and high density lipoprotein-cholesterol between men with optimal and high-normal plus high blood pressure. Similar differences were found between men in a top versus low tertile of systolic and diastolic blood pressure. In multiple regression analysis, both log leptin and log insulin emerged as determinants for systolic blood pressure independent of body mass index and percentage body fat, but an association with diastolic blood pressure was only shown for log leptin.

CONCLUSION

Hyperleptinemia and hyperinsulinemia may be regulators of arterial pressure, independent of body mass index or percentage body fat.

CDR substitutions of a humanized monoclonal antibody (CC49): contributions of individual CDRs to antigen binding and immunogenicity

One of the major obstacles in the successful clinical application of monoclonal antibodies has been the development of host immune responses to murine Ig constant and variable regions. While the CDR grafting of MAbs may alleviate many of these problems, the potential remains that one or more murine CDRs on the human Ig backbone of a "humanized" MAb may still be immunogenic. Studies were undertaken employing a MAb of potential clinical utility, CC49, to define those CDRs that are essential for antigen binding and those that may be immunogenic in humans. We previously developed a humanized CC49 (HuCC49) by grafting the MAb CC49 hypervariable regions onto frameworks of human MAbs. To identify those CDRs essential for binding, a panel of variant HuCC49 MAbs was generated here by systematically replacing each of the murine CDRs with their human counterparts. The relative affinity constant of each variant was determined. Serum from a patient who received murine CC49 was used to determine the potential immunogenicity of each CDR in humans. The serum was shown to react with the anti-CC49 variable region. Results showed that patients' anti-idiotypic responses are directed mainly against LCDR3 and moderately against LCDR1 and HCDR2. These studies demonstrate for the first time that variants containing individual CDR substitutions of a humanized MAb can be constructed, and each CDR can be defined for the two most important properties for potential clinical utility: antigen binding and immunogenicity.

Antitumor effects of interleukin-2 gene-modified fibroblasts in an orthotopic colon cancer model

We transduced the interleukin-2 (IL-2) gene into murine fibroblasts BALBCL7 or murine colon cancer CT26 using a retroviral vector. BALBCL7 transduced with IL-2 gene secreted 748 pg/ml of IL-2, whereas IL-2 gene-modified CT26 secreted 1,167 pg/ml of IL-2 (48 h incubation, 1x10(6)/ml). Then, we inoculated gene-modified BALBCL7 and/or CT26 cells into BALB/c female mice, and observed the tumor growth. The tumor growth was inhibited in mice inoculated with parental CT26 plus IL-2 gene-modified BALBCL7, compared with that in mice given parental CT26 alone (P<0.01). Moreover, we investigated the cytotoxic activity of spleen cells derived from mice treated with gene-modified cells, and performed phenotypic analysis of the effector cells. The killer cells derived from mice inoculated with IL-2 gene-modified BALBCL7 plus parental CT26 showed higher cytotoxic activity than those from mice inoculated with CT26 alone. The cytotoxic activity was almost completely blocked by anti-CD8 antibody (Ab), and partially blocked by anti-asialo GM1 Ab. Next, we inoculated CT26 tumor tissue into murine cecum orthotopically, and treated the animals with gene-modified BALBCL7 plus parental CT26. The tumor size in the cecum was significantly decreased, compared with parental CT26 alone (P<0.01).

P-glycoprotein-expressing tumor cells are resistant to anticancer drugs in human gastrointestinal cancer

The resistance to doxorubicin (DOX) by some tumor cells is mainly due to the effect of P-glycoprotein encoded by the multidrug resistance-1 (mdr1) gene. We tried to prove the correlations between P-glycoprotein expression and the sensitivity for anticancer drugs including DOX and other cytotoxic drugs that are currently used for gastrointestinal cancer patients. We quantified the P-glycoprotein expression by flow cytometry techniques, and the sensitivity for anticancer drugs using a tetrazolium salt, 3-(4,5-di-methylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), assay in highly purified fresh human tumor cells obtained from 25 cancer patients. The inhibition rates were the lowest in DOX and mitomycin C (MMC), compared with other drugs. The most significant correlation between DOX and MMC was seen in the inhibition rates. A significant correlation was also seen between the inhibition rates for DOX and P-glycoprotein expression, whereas only a slight correlation between the sensitivity for MMC and P-glycoprotein expression was observed. We should therefore pay close attention to the effect of P-glycoprotein when treating cancer patients, especially if both the inhibition rates of DOX and MMC are low based on the findings of an MTT assay.

Clinical evaluation of hepatic arterial infusion of low dose-CDDP and 5-FU with hyperthermotherapy: a preliminary study for liver metastases from esophageal and gastric cancer

BACKGROUND/AIMS

The prognosis for gastric and esophageal cancer patients with liver metastases remains very poor. In most cases, liver metastasis is unresectable because of its number, size and location and therefore, other approaches need to be considered.

METHODOLOGY

In this study we examined 4 patients. We showed the therapeutic benefits of employing hepatic arterial infusion of low-dose CDDP and 5-FU combined with hyperthermia for the treatment of liver metastases of gastric and esophageal cancer.

RESULTS

All patients showed partial response, and bone marrow toxicities and gastrointestinal toxicities were extremely slight while liver toxicities were not observed at all. Moreover, 3 of the patients excluding patient 3 who had metastatic lesions other than liver metastases have still been alive for more than 17 months (17-28 months) maintaining a good quality of life.

CONCLUSIONS

Therefore, it is suggested that the merits of both low dose-FP and hepatic arterial infusion chemotherapy contribute to ideal clinical effects, and that hyperthermotherapy could enhance clinical responses without potentiating any toxicities. However, this is just a preliminary study, and therefore, a prospective randomized control study is necessary to evaluate the efficiency of this therapy.

Interhemispheric asymmetry of event-related fields concerned with logical processing during auditory oddball stimulation

This study investigated the cortex during logical processing of auditory information using a 122-channel dc-SQUID gradiometer. The experimental task was designed to require a simple logical decision prior to counting rare paired tones, which consisted of two different pitches and were presented to separate ears. Among six subjects, left and right predominant dipolar activity was observed in three subjects each. When the dipolar sources were superimposed on MR images, the inferior region of the supramarginal gyrus showed activation, suggesting that logical processing occurred in the association cortex but not in the auditory cortex. We propose a modified cognitive sequence model in which auditory information processed in Heschl's gyri is transmitted to the supramarginal gyrus to commence automatic detection processing.

Characterization of the mechanisms involved in the gender differences in hepatic taurocholate uptake

Gender differences in the hepatic transport of organic anions is well established. Although uptake of many organic anions is greater in females, sodium-dependent taurocholate uptake is greater in hepatocytes from male rats. We examined the hypothesis that endogenous estrogens alter the number of sinusoidal bile acid transporters and/or decrease membrane lipid fluidity. The initial sodium-dependent uptake of [3H]taurocholate was 75% greater in hepatocytes from males than from either intact or oophorectomized females rats. Taurocholate maximal uptake was increased twofold (P < 0.03) without a significant change in the Michaelis-Menten constant. Sinusoidal membrane fractions were isolated from male and female rat livers with equal specific activities and enrichments of Na+-K+-ATPase. Males had a significant (P < 0.05) increase in cholesterol esters and phosphatidylethanolamine-to-phosphatidylcholine ratio. Fluorescence polarization indicated decreased lipid fluidity in females. In females, expression of the sodium-dependent taurocholate peptide (Ntcp) and mRNA were selectively decreased to 46 +/- 9 and 54 +/- 4% (P < 0.01), respectively, and the organic anion transporter peptide (Oatp) and Na+-K+-ATPase alpha-subunit were not significantly different. Nuclear run-on analysis indicated a 47% (P < 0.05) decrease in Ntcp transcription, without a significant change in Oatp. In conclusion, these studies demonstrated that decreased sodium-dependent bile salt uptake in female hepatocytes was due to decreased membrane lipid fluidity and a selective decrease in Ntcp.

P-glycoprotein expression and chemosensitivity in highly purified fresh human gastrointestinal cancer cells

BACKGROUND/AIMS

Colorectal cancer is one of the tumors most refractory to treatment by chemotherapy. One of the major problems associated with cancer chemotherapy is drug-resistance of tumor cells, and resistance to doxorubicin (DOX) is mainly due to the effect of P-glycoprotein. We have tried to prove the correlation between P-glycoprotein expression and DOX-sensitivity in highly purified fresh human colorectal cancer and, moreover, to prove the differentiation of P-glycoprotein expression between the different kinds of cancers, including gastric cancer.

METHODOLOGY

The present study was designed to quantify P-glycoprotein expression by flow cytometry, and DOX-sensitivity by MTT assay in highly purified fresh human tumor cells obtained from 29 cancer patients including 13 colorectal cancers and 16 gastric cancers.

RESULTS

DOX-sensitivity decreased in proportion to P-glycoprotein expression in colorectal cancer. P-glycoprotein expression in colorectal cancer was higher than that in gastric cancer. Particularly, P-glycoprotein expression in colorectal cancer in the DOX low-sensitivity group was higher than in the DOX high-sensitivity group.

CONCLUSIONS

The chemotherapeutic management of patients with colorectal cancer might be more effective if we can circumvent the effect of P-glycoprotein.