Comparison of mediastinal lymph node metastases from adenocarcinoma of the esophagogastric junction versus lower esophageal squamous cell carcinoma with involvement of the esophagogastric junction.

The distribution of mediastinal lymph node metastasis in patients with adenocarcinoma of the esophagogastric junction (AEG) remains unclear. Additionally, the distribution of nodal mediastinal metastasis from squamous cell carcinoma (SCC) of the lower esophagus with involvement of the esophagogastric junction remains unclear, given the very limited number of these patients. In this retrospective review, we compared the outcomes of radical lymphadenectomy of the mediastinum, including upper mediastinal lymphadenectomy, between patients with AEG and those with SCC. From 2005 to 2017, 69 consecutive patients underwent esophagectomy via right thoracotomy or minimally invasive esophagectomy for a Siewert type I or II tumor with esophageal invasion ≥3 cm. We analyzed the incidences of mediastinal lymph node metastasis in this group relative to those of 73 patients with SCC with involvement of the esophagogastric junction who consecutively underwent esophagectomy during the same period. Mediastinal lymph node metastasis was seen in 26 of 69 patients with AEG (38%), with upper, middle, lower mediastinal nodal metastasis instances of 20%, 17%, and 23%, respectively. Mediastinal lymph node metastasis was seen in 23 of 73 patients with SCC (32%), with upper, middle, lower mediastinal nodal metastasis instances of 12%, 16%, and 19%, respectively. This mediastinal lymph nodal metastasis distribution did not statistically differ between patients with AEG and those with SCC. The relapse-free survival outcomes were poor for patients with clinical (P < 0.01) or pathological (P < 0.01) nodal metastasis of the mediastinum with AEG. In contrast, patients with clinical or pathological mediastinal nodal metastases of SCC did not have extremely poor survival outcomes, compared to patients with AEG. Despite the limited dataset available for analysis, patients with AEG and those with SCC might exhibit similar incidences and distribution of mediastinal lymph node metastasis. However, the clinical or pathological metastasis of AEG to the mediastinum was associated with poor survival outcomes, even if radical mediastinal lymphadenectomy including the upper mediastinal lymphadenectomy was performed.

Oesophagectomy with or without supraclavicular lymphadenectomy after neoadjuvant treatment for squamous cell carcinoma of the oesophagus.

BACKGROUND: Treatment of supraclavicular nodes remains controversial among patients with oesophageal squamous cell carcinoma. This study assessed the outcomes of patients who underwent oesophagectomy with or without supraclavicular lymphadenectomy after neoadjuvant treatment. METHODS: This was a single-centre retrospective cohort study. Patients with oesophageal squamous cell carcinoma and clinically negative supraclavicular nodes who underwent oesophagectomy after neoadjuvant treatment between January 2005 and December 2015 were included. Overall and relapse-free survival were compared between patients who did or did not undergo supraclavicular nodal dissection. Propensity score matching was used to correct for differences in prognostic factors between the groups. RESULTS: Some 223 patients underwent supraclavicular lymphadenectomy. The prevalence of pathologically confirmed supraclavicular metastasis was 10·3 per cent, and these patients had poor 5-year relapse-free (7 per cent) and overall (14 per cent) survival. Only two of 55 patients who did not undergo supraclavicular lymphadenectomy had recurrent disease in the supraclavicular region without distant metastasis. There was no statistically significant difference between the groups in relapse-free survival (hazard ratio (HR) 0·95, 95 per cent c.i. 0·61 to 1·47; P = 0·821) or overall survival (HR 0·86, 0·52 to 1·40; P = 0·544). Similarly, no significant difference in relapse-free or overall survival was observed between the propensity score-matched groups. CONCLUSION: For patients with clinically negative supraclavicular lymph nodes, prophylactic supraclavicular lymphadenectomy may be omitted when neoadjuvant treatment is administered.

Prediction of lateral pelvic node involvement in low rectal cancer by conventional computed tomography.

BACKGROUND: The clinical significance of lateral pelvic lymphatic spread in rectal cancer remains unknown. The present study aimed to assess the accuracy of preoperative computed tomography (CT) for prediction of lateral node involvement in patients with low rectal cancer and to determine the prognostic significance of extended lateral node dissection. METHODS: A total of 109 patients with primary low rectal cancer were enrolled in this prospective cohort study. The preoperative CT findings were compared with the histopathological results and with follow-up data. RESULTS: CT diagnosed lateral lymph node status with high accuracy (sensitivity 95 per cent, specificity 94 per cent), in marked contrast to mesorectal node status. Of 68 patients who had R0 resection without lateral node dissection, only two developed pelvic wall recurrence during median follow-up of 4.1 years. Metastatic nodes in the lateral pelvic region were significantly larger than those in the mesorectum (P < 0.001). CONCLUSION: CT accurately predicted lateral lymph node status in low rectal cancer, allowing preoperative identification of patients who might benefit from extended lateral node dissection.

Insulin resistance and increased pancreatic beta-cell proliferation in mice expressing a mutant insulin receptor (P1195L).

Several mutations of the tyrosine kinase domain of insulin receptor (IR) have been clinically reported to lead insulin resistance and insulin hypersecretion in humans. However, it has not been completely clarified how insulin resistance and pancreatic beta-cell function affect each other under the expression of mutant IR. We investigated the response of pancreatic beta-cells in mice carrying a mutation (P1195L) in the tyrosine kinase domain of IR beta-subunit. Homozygous (Ir(P1195L/P1195L)) mice showed severe ketoacidosis and died within 2 days after birth, and heterozygous (Ir(P1195L/wt)) mice showed normal levels of plasma glucose, but high levels of plasma insulin in the fasted state and after glucose loading, and a reduced response of plasma glucose lowering effect to exogenously administered insulin compared with wild type (Ir(wt/wt)) mice. There were no differences in the insulin receptor substrate (IRS)-2 expression and its phosphorylation levels in the liver between Ir(P1195L/wt) and Ir(wt/wt) mice, both before and after insulin injection. This result may indicate that IRS-2 signaling is not changed in Ir(P1195L/wt) mice. The beta-cell mass increased due to the increased numbers of beta-cells in Ir(P1195L/wt) mice. More proliferative beta-cells were observed in Ir(P1195L/wt) mice, but the number of apoptotic beta-cells was almost the same as that in Ir(wt/wt) mice, even after streptozotocin treatment. These data suggest that, in Ir(P1195L/wt) mice, normal levels of plasma glucose were maintained due to high levels of plasma insulin resulting from increased numbers of beta-cells, which in turn was due to increased beta-cell proliferation rather than decreased beta-cell apoptosis.

Morphological characteristics and electrophysiological properties of CA1 pyramidal neurons in macaque monkeys.

Little is known about the morphological characteristics and intrinsic electrophysiological properties of individual neurons in the nonhuman primate hippocampus. We have used intracellular recording and biocytin-labeling techniques in the in vitro hippocampal slice preparation to provide quantitative evaluation of the fundamental morphological and intrinsic electrophysiological characteristics of macaque monkey CA1 pyramidal neurons. These neurons have previously been studied in the rat in our laboratory. Monkey CA1 pyramidal neurons have an average soma volume of 3578 microm3, 4.71 basal dendrites with 53 terminal branches for a dendritic length of about 10,164 microm, 1.13 apical dendrites with 47 terminal branches for a dendritic length of about 10,678 microm. In comparison, rat CA1 pyramidal neurons have an average soma volume of 2066 microm3, 3.35 basal dendrites with 29 terminal branches for a dendritic length of about 4,586 microm, 1.43 apical dendrites with 62 terminal branches for a dendritic length of about 8,838 microm. The basic intrinsic electrophysiological properties of CA1 pyramidal cells are similar in monkeys and rats. Monkey CA1 pyramidal neurons have a resting membrane potential of about -62 mV (rat: -62 mV), an input resistance of 35 MOmega (rat: 34-49 MOmega), a rheobase of 0.17 nA (rat: 0.12-0.20 nA) and an action potential amplitude of 83 mV (rat: 71-89 mV). Although morphological differences such as the increased dendritic length may translate into differences in neural processing between primates and rodents, the functional significance of these morphological differences is not yet clear. Quantitative studies of the primate brain are critical in order to extrapolate information derived from rodent studies into better understanding of the normal and pathological function of the human hippocampus.

B(0)-B(0) mixing in unquenched lattice QCD.

We present an unquenched lattice calculation for the B(0)-B(0) transition amplitude. The calculation, carried out at an inverse lattice spacing 1/a=2.22(4) GeV, incorporates two flavors of dynamical quarks described by the O(a)-improved Wilson fermion action and heavy quarks described by nonrelativistic QCD. Particular attention is paid to the uncertainty that arises from the chiral extrapolation, especially the effect of pion loops, for light quarks, which we find could be sizable for the leptonic decay constant, whereas it is small for the B parameters. We obtain f(B(d))=191(10)(+12-22) MeV, f(B(s))/f(B(d))=1.13(3)(+13-2), B(B(d))(m(b))=0.836(27)(+56-62), B(B(s))/B(B(d))=1.017(16)(+56-17), and xi=1.14(3)(+13-2), where the first error is statistical, and the second is systematic, including uncertainties due to chiral extrapolation, finite lattice spacing, heavy quark expansion, and perturbative operator matching.

[Mitral valve stenosis due to primary cardiac granulocytic sarcoma relapsing 8 years after complete remission: a case report].

A 28-year-old man was admitted because of dyspnea on effort. His tricuspid valve had been affected by granulocytic sarcoma and manifested tricuspid valve stenosis 8 years previously. After chemotherapy and radiation therapy, the tumor had disappeared and the tricuspid valve stenosis was relieved. Echocardiography showed that the posterior leaflet of the mitral valve was affected by the tumor, and Doppler ultrasonography revealed mild mitral valve stenosis. Biopsy of the anterior chest wall detected granulocytic sarcoma. Chemotherapy was started. The tumor size was reduced and the mitral valve stenosis became slight. Primary cardiac granulocytic sarcoma is very rare and stenosis of the atrioventricular valve by relapse of this tumor after complete remission is extremely unusual.

[Effect of peroral doxifluridine plus hepatic arterial infusion for synchronous liver metastasis of colorectal cancer--correlation with the expression of thymidine phosphorylase and dihydropyrimidine dehydrogenase in primary colorectal cancer lesions].

We investigated whether the efficacy of peroral doxifluridine and hepatic arterial 5-FU infusion on synchronous liver metastasis of colorectal cancer could be predicted based on the expression of thymidine phosphorylase (TP) and dihydropyrimidine dehydrogenase (DPD) in the primary colorectal lesions. Ten patients with synchronous liver metastasis of colorectal cancer were given doxifluridine (600-800 mg/body/day) orally and 5-FU (500 mg/body, once or twice a week) through the hepatic artery following resection of the primary lesions between June 1996 and July 2001. The levels of TP and DPD in the primary lesions were determined by an enzyme-linked immunosorbent assay. The level of TP, DPD, and the ratio of TP/DPD in patients with partial response (n = 4) were 89.8 +/- 30.0 U/mg protein, 23.5 +/- 25.7 U/mg protein, and 3.8 +/- 1.4, respectively, while those in patients with no response or progressive disease (n = 6) were 41.8 +/- 9.7 U/mg protein, 25.8 +/- 15.8 U/mg protein, and 2.2 +/- 1.6, showing significant difference (p < 0.01) in the level of TP between the groups. These results indicate that determining the level of TS in primary colorectal lesions may be useful for predicting the efficacy of this regimen for patients with synchronous liver metastasis of colorectal cancer.

Randomized phase I study of standard-fractionated or accelerated-hyperfractionated radiotherapy with concurrent cisplatin and vindesine for unresectable non-small cell lung cancer: a report of Japan Clinical Oncology Group Study (JCOG 9601).

BACKGROUND: We attempted dose escalation of standard-fractionated and accelerated-hyperfractionated radiotherapy combined with concurrent cisplatin and vindesine to improve local control and survival in unresectable non-small cell lung cancer. METHODS: Twenty-one patients were enrolled between June 1996 and August 1997. There were 19 males and two females and their median age was 65 years (range 45-74 years). Performance status was 0 in 10 cases and 1 in 11 cases. Disease stage was IIIA in three cases and IIIB in 18 cases. The cases were randomized to a standard-fractionated arm (n = 10) or an accelerated-hyperfractionated radiotherapy arm (n = 11) with two or three cycles of concomitant cisplatin 80 mg/m(2) on day 1 and vindesine 3 mg/m(2) on days 1 and 8 every 4 weeks in both arms. Dose escalation from 60 Gy/30 fractions/6 weeks to 70 Gy/35 fractions/7 weeks was planned in the standard-fractionated radiotherapy group and from 54 Gy/36 fractions/3.6 weeks to 60 Gy/40 fractions/4 weeks and then 66 Gy/44 fractions/4.4 weeks in the accelerated-hyperfractionated radiotherapy group. RESULTS: Grade 3 or 4 hematological toxicities were observed as follows: in the standard-fractionated/accelerated-hyperfractionated radiotherapy group, leukocytopenia 9/10, anemia 2/3 and thrombocytopenia 0/2. Grade 3 non-hematological toxicity consisted of esophagitis 0/3, increased serum total bilirubin 2/0 and hypoxia 0/1. Two patients died of radiation pneumonitis in the standard-fractionated radiotherapy group. Dose-limiting toxicity was observed in four of the 10 and seven of the 11 patients at initial dose level of standard-fractionated radiotherapy, 60 Gy/30 fractions/6 weeks, and of accelerated-hyperfractionated radiotherapy, 54 Gy/36 fractions/3.6 weeks, respectively. Thus, we failed to escalate the dose of radiotherapy in both arms. The overall response rate in the standard-fractionated group and the accelerated-hyperfractionated radiotherapy group was 70 and 73% and the 1-year survival rate was 70 and 64%, respectively. CONCLUSIONS: We concluded that these schedules of radiotherapy with concurrent cisplatin and vindesine were unacceptable for use in patients with unresectable non-small cell lung cancer. Further modifications of the schedule for radiotherapy and evaluation of combination with new chemotherapy are warranted.

Angiotensin II type 2 receptor mediates vascular smooth muscle cell apoptosis in cystic medial degeneration associated with Marfan's syndrome.

BACKGROUND: Cystic medial degeneration (CMD) is a histological abnormality that is common in the aortic diseases associated with Marfan's syndrome (MFS). Although little known about the mechanism underlying CMD, several recent reports have demonstrated that vascular smooth muscle cell (VSMC) apoptosis could play a substantial role in CMD. On the other hand, angiotensin II (Ang II) has been reported to play an important role in the regulation of VSMC growth and apoptosis via the Ang II type 1 receptor (AT1R) and type 2 receptor (AT2R). METHODS AND RESULTS: To elucidate the role of Ang II signaling via the Ang II receptors in CMD, we investigated AT1R and AT2R mRNA expression and tissue concentration of Ang II in MFS aortas (n=10) and control aortas (n=12). Furthermore, we examined the effects of an ACE inhibitor, an AT1R blocker, and an AT2R blocker on serum deprivation-induced VSMC apoptosis by organ culture system. AT1R expression was significantly decreased (P<0.01) and AT2R expression was significantly increased (P<0.001) in MFS aortas compared with control aortas, and tissue Ang II concentration was significantly higher in CMD than in the control condition (P<0.01). Both the ACE inhibitor and AT2R blocker significantly inhibited serum deprivation-induced VSMC apoptosis (P<0.05), although the AT1R blocker did not inhibit apoptosis in cultured aortic media from MFS patients. CONCLUSIONS: Accelerated ACE-dependent Ang II formation and signaling via upregulated AT2R play a pivotal role in VSMC apoptosis in CMD, and the ACE inhibitor could have clinical value in the prevention and treatment of CMD.

The continual reassessment method and its applications: a Bayesian methodology for phase I cancer clinical trials.

We discuss the continual reassessment method (CRM) and its extension with practical applications in phase I and I/II cancer clinical trials. The CRM has been proposed as an alternative design of a traditional cohort design and its essential features are the sequential (continual) selection of a dose level for the next patients based on the dose-toxicity relationship and the updating of the relationship based on patients' response data using Bayesian calculation. The original CRM has been criticized because it often tends to allocate too toxic doses to many patients and our proposal for overcoming this practical problem is to monitor a posterior density function of the occurrence of the dose limiting toxicity (DLT) at each dose level. A simulation study shows that strategies based on our proposal allocate a smaller number of patients to doses higher than the maximum tolerated dose (MTD) compared with the original method while the mean squared error of the probability of the DLT occurrence at the MTD is not inflated. We present a couple of extensions of the CRM with real prospective applications: (i) monitoring efficacy and toxicity simultaneously in a combination phase I/II trial; (ii) combining the idea of pharmacokinetically guided dose escalation (PKGDE) and utilization of animal toxicity data in determining the prior distribution. A stopping rule based on the idea of separation among the DLT density functions is discussed in the first example and a strategy for determining the model parameter of the dose-toxicity relationship is suggested in the second example.

Patent foramen ovale as a possible risk factor for cryptogenic brain abscess: report of two cases.

OBJECTIVE AND IMPORTANCE: Patent foramen ovale (PFO) has been suggested as a potential source of paradoxical embolism. A higher prevalence of PFO in ischemic stroke of unexplained cause has been recognized. Brain abscesses are commonly associated with a contiguous focus of infection, hematogenous spread from a distant focus, or cranial trauma. However, no predisposing factors, including a distant focus with unknown cause, are identified in approximately 15 to 30% of reported cases. CLINICAL PRESENTATION: We encountered two patients with brain abscess presumably caused by dental infections. Both patients displayed PFO, through which right-to-left atrial contrast shunting was revealed by transesophageal echocardiography. Although the radiological location of the abscesses suggested hematogenous spread as a cause, the patients had no arteriovenous shunting other than the PFO, despite exhaustive investigations for a potential infectious route. The patients displayed no definite focal orofacial inflammatory signs during the postoperative course despite diagnosis of pyorrhea alveolaris or periodontitis. INTERVENTION: In Patient 1, the abscess was aspirated stereotactically, and in Patient 2, the abscess disappeared radiologically after high-dose antibiotic treatment. CONCLUSION: The mechanism of brain abscess formation putatively related to PFO should be different from that related to common dental sepsis. Analysis of these cases suggested that infectious embolism from a latent or even identifiable focus through the PFO may be an underrecognized cause of brain abscess, in contrast to simple seeding of the brain via transit of the infecting bacteria through the valveless emissary veins.

Laminar organization of the pyramidal cell layer of the subiculum in the rat.

The distribution of neurons in the subiculum of the rat that give rise to subcortical connections was studied using retrograde labeling with horseradish peroxidase conjugated to wheat germ agglutinin. Injections were made into the anteroventral thalamic nucleus, the medial mammillary nucleus, the nucleus accumbens, and the lateral septal nucleus. To facilitate the analysis, the hippocampal formation with adjacent cortices were "flattened," which allowed the cutting of sections perpendicular to the full septotemporal axis. Cells projecting to the anteroventral thalamic nucleus (AV cells), the medial mammillary body (MMB cells), and the nucleus accumbens (ACC cells) were observed consistently throughout the entire septotemporal (dorsoventral) and transverse extent of the subiculum (from field CA1 of the hippocampus to the presubiculum). In the transverse plane, the three kinds of projection cells were arranged in a laminar fashion: The AV cells were observed in the deepest portion of the subicular pyramidal cell layer, the ACC cells were observed in the most superficial portion of the layer, and the MMB cells were observed in the middle portion of the layer. Although this laminar arrangement was observed at all septotemporal levels of the subiculum, it was most apparent at the septal level. At more temporal levels, the "laminae" shifted such that the superficially located ACC cells were more prominent in the proximal half of the subiculum, whereas the AV cells were shifted toward the distal half of the subiculum. The average size of somata of the AV cells was 72.3 microm(2), that of the ACC cells was 105.2 microm(2), and that of the MMB cells was 121.8 microm(2). The connectional and cytoarchitectonic data indicate that there is a distinct sublamination of the subicular pyramidal cell layer, suggesting that the subiculum may be analogous to the infragranular layer (layers V and VI) of the isocortex.

Dynamical quark effects on light quark masses

Light quark masses are calculated in lattice QCD with two degenerate flavors of dynamical quarks. The calculations are made with improved actions with lattice spacing a = 0.22-0.11 fm. In the continuum limit we find m(M&Smacr;)(ud)(2 GeV) = 3.44(+0.14)(-0.22) MeV using the pi and rho meson masses as physical input, and m(M&Smacr;)(s)(2 GeV) = 88(+4)(-6) MeV or 90(+5)(-11) MeV with the K or straight phi meson mass as additional input. The quoted errors represent statistical and systematic combined, the latter including those from continuum and chiral extrapolations, and from renormalization factors. Compared to quenched results, two flavors of dynamical quarks reduce quark masses by about 25%.

[Combination chemotherapy with irinotecan hydrochloride plus carboplatin for patients with advanced or recurrent colorectal cancer--a pilot study].

A pilot study was performed to evaluate the feasibility and efficacy of irinotecan hydrochloride (CPT-11) plus carboplatin (CBDCA) for treatment of advanced or recurrent colorectal cancer. Fifteen patients with colorectal cancer (nonresectable, 1; noncurative resection, 5; recurrent disease, 9) were treated with CPT-11 (40-50 mg/m2) plus CBDCA (70-100 mg/m2) once a week for 2-3 weeks followed by a one-week rest. This treatment was repeated until disease progression or severe toxic effects were found. The total dose of CPT-11 ranged from 135 to 1,214 (median, 467) mg/m2 and that of CBDCA ranged from 267 to 2,022 (median, 933) mg/m2. Adverse effects included nausea (grade 2) in 2 (13.3%) diarrhea (grade 2) in 2 (13.3%), leukopenia (grade 3) in 2 (13.3%), thrombocytopenia (grade 1) in one (6.7%), and hair falling (grade 3) in one (6.7%). The response rate of 14 evaluable patients was 14.3% (CR, 1; PR,1; NC,7; PD,5). The median survival time of all patients was 405 days from the start of chemotherapy. The survival time of patients with CR, PR, and NC (n = 9) tended to be longer than that of those with PD (n = 5) (p = 0.06). The median time to disease progression was 105 days. These results suggest that this combination chemotherapy is feasible and effective in the treatment of advanced or recurrent colorectal cancer.

[Continual reassessment method (CRM)].

We discuss the basic concept of the continual reassessment method (CRM) and some modifications. The CRM has been proposed as alternatives of traditional cohort design for phase I trials in cancer. To focus on the dilemma between ethical concern and scientific purpose, we review the requirement for the phase I settings and the issues of the traditional cohort design. Then, CRM is introduced so that the essential feature is in the sequential (continual) selection of a dose level for next patients based on the dose-toxicity relationship and in updating the relationship based on patients' response date using Bayesian calculation. Finally we discuss both advantages and pitfalls in practice.

The influence of different insufflation pressures during carbon dioxide pneumoperitoneum on the development of pulmonary metastasis in a mouse model.

BACKGROUND: The effects of different insufflation pressures on the development of pulmonary metastasis was investigated in a mouse laparoscopy model. METHODS: BALB/C mice intravenously inoculated with colon 26 cells were randomized to one of five treatment groups (10 mice per group): pneumoperitoneum at different pressures of 5, 10 or 15 mmHg; full laparotomy for 60 min; or anesthesia control. Cancer nodules on the lung surface 19 days postoperatively were compared between groups. RESULTS: (a) As compared with the control group, pneumoperitoneum at 10 and 15 mmHg and laparotomy enhanced the growth of pulmonary metastases (p < 0.01). (b) The growth of metastases also was greater in laparotomy group mice than in mice undergoing pneumoperitoneum at 5 and 10 mmHg (p < 0.05). CONCLUSIONS: These results suggest that the effects of different insufflation pressures on the growth of pulmonary metastases are not identical, and that pneumoperitoneum with high pressure may promote pulmonary metastases similar to those with laparotomy.

Performance of a monolithic silica column in a capillary under pressure-driven and electrodriven conditions

A continuous macroporous silica gel network was prepared in a fused-silica capillary and evaluated in reversed-phase liquid chromatography. Under pressure-driven conditions, the monolithic silica column derivatized to C18 phase (100 microns in diameter, 25 cm in length, silica skeleton size of approximately 2.2 microns) produced plate heights of about 23 and 81 microns at 0.5 mm/s with a pressure drop of 0.4 kg/cm2, and at 4.0 mm/s with 3.6 kg/cm2, respectively, in 90% acetonitrile for hexylbenzene with a k value of 0.7. The separation impedance, E, calculated for the present monolithic silica column was much smaller at a low flow rate than those for particle-packed columns, although higher E values were obtained at a higher flow rate. Considerable dependence of column efficiency on the linear velocity of the mobile phase was observed despite the small size of the silica skeletons. A major source of band broadening in the HPLC mode was found in the A term of the van Deemter equation. The performance of the continuous silica capillary column in the electrodriven mode was much better than that in the pressure-driven mode. Plate heights of 7-8 microns were obtained for alkylbenzenes at 0.7-1.3 mm/s, although the electroosmotic flow was slow. In HPLC and CEC mode, the dependency of plate height on k values of the solutes was observed as seen in open tube chromatography presumably due to the contribution of the large through-pores. Since monolithic silica capillary columns can provide high permeability, the pressure-driven operation at a very low pressure can afford a separation speed similar to CEC at a high electric field.