Fiber-in-tube solid-phase microextraction: a fibrous rigid-rod heterocyclic polymer as the extraction medium

A novel "fiber-in-tube" configuration has been applied to the extraction tube of solid phase microextraction (SPME), and the direct coupling of the extraction process to liquid chromatography (LC) has been accomplished for the analysis of n-butylphthalate in wastewater. By using this fiber-in-tube SPME/LC system the preconcentration factor for the phthalate was about 160 with 20 min extraction and no interference peak was observed in the chromatogram. The results also showed the potential applications of this fiber-in-tube SPME/LC for the analysis of sub-ppb level (i.e., lower than 1 ng/mL) of various organic analytes in aqueous sample matrix without a large solvent consumption during the preconcentration process.

Comparison of separation behavior of benzodiazepines in packed capillary electrochromatography and open-tubular capillary electrochromatography

Packed column capillary electrochromatography (CEC), open-tubular CEC and microcolum liquid chromatography (LC) using a cholesteryl silica bonded phase have been studied to compare the retention behavior for benzodiazepines. It has been found that packed column CEC gives better resolution, faster analysis time than microcolumn LC for benzodiazepines maintaining similar selectivity except for some solutes which are charged species under the separation conditions. However, open-tubular CEC gave different selectivities to a larger extent for charged benzodiazepines from that which should be produced by the chromatographic properties of the cholesteryl silica phase. Charged species migration times are mainly influenced by electrophoretic mobility rather than the chromatographic interactions.

Fullerenes separation with monomeric type C30 stationary phase in high-performance liquid chromatography

The temperature effect on the separation of fullerenes in LC was examined using monomeric type C30, C18 and C8 alkyl bonded stationary phases. It appears that the C30 phase exhibits superior separation ability for fullerenes. It is observed that the maximum retention temperature of fullerenes on the C30 phase is around 20 degrees C. A strong correlation between the changes in NMR spectra and the retention behavior of the solutes was found. The interpretation of the retention behavior of fullerenes on the alkyl bonded stationary phases, including the behavior in subambient temperature, is discussed using the information obtained by CP-MAS solid-state NMR spectroscopy and LC.

Direct coupling of microcolumn liquid chromatography with in-tube solid-phase microextraction for the analysis of antidepressant drugs

The direct coupling of in-tube solid-phase microextraction (in-tube SPME) with microcolumn liquid chromatography (micro-LC) has been investigated for the analysis of antidepressants in human urine. The use of in-tube SPME has been clearly shown to be advantageous for the on-line coupling of the SPME method, as the sample pretreatment technique, with micro-LC as the separation technique. This is because much smaller amounts of the sample solutions, desorption solvents and the mobile phase are required compared with conventional SPME-LC systems. The parameters for preconcentration have been investigated for the extraction capillary with the newly developed 'wire-in-tube' configuration.

Evaluation of endoscopic injection sclerotherapy with and without simultaneous ligation for the treatment of esophageal varices

For more effective and simple endoscopic injection sclerotherapy (EIS) for esophageal varices, we developed an EIS procedure with ligation (EISL) that is non-invasive, in which EIS and endoscopic variceal ligation (EVL) are performed simultaneously. In this study, we compared EISL and EIS in a randomized sample of patients (n = 14 for each procedure). For EISL, EVL was performed, including the injection site, after the injection of 5% ethanolamine oleate with iopamidol (EOI) into a varix. The mean number of treatment sessions required for eradication of esophageal varices was 2.3+/-0.5 for EISL and 3.9+/-0.8 for EIS (P < 0.001); the mean number of treatment sites was 6.2+/-2.2 for EISL and 14.0+/-5.0 for EIS (P < 0.001); the mean total amount of EOI used was 13.8+/-5.2ml for EISL and 26.3+/-9.8ml for EIS (P < 0.001). There were no significant differences in rates of recurrence of varices or in bleeding between the two groups. For EISL, fewer treatment sessions and less sclerosant were sufficient, probably because the sclerosants were more effective due to the blockage of variceal blood flow by the ligation. This method should provide a novel modification of EIS.

Preparation of capillary columns coated with linear polymer containing hydrophobic and charged groups for capillary electrochromatography

A linear polymer-coated capillary was prepared by in-capillary copolymerization of N-tert-butylacrylamide (TBAAm) with a charged monomer, 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS), after the capillary pretreatment with a bifunctional reagent. The coated capillaries were applied in capillary electrochromatographic (CEC) separation of small neutral compounds. Hydrophobic groups in the linear polymer, which were immobilized onto the capillary surface, functioned as the stationary phase in reversed-phase CEC separation, and charged groups in the linear polymer generated electroosmotic flow (EOF) along the column. The coated capillaries were prepared by a simple procedure. Moreover, the reproducibility with respect to EOF rate and migration times of the solutes was excellent. The results for CEC separation of small molecules using the linear polymer-coated capillaries are presented.

Clinical significance of plasma vascular endothelial growth factor in gastrointestinal cancer

Circulating vascular endothelial growth factor (VEGF) was measured in gastric and colorectal cancer patients using an enzyme-linked immunosorbent assay (ELISA). Firstly, serum and plasma samples were collected from 20 normal controls to compare the values of VEGF and to determine which specimen type was most suitable for detecting circulating VEGF. Seventeen of 20 normal controls had plasma VEGF levels under the limit of detection (15 pg/ml) and the levels of the remaining three controls were 21, 22 and 38 pg/ml. In contrast, all serum samples indicated high levels of VEGF (mean 238 pg/ml), ranging from 44 to 450 pg/ml. In a time-course test of two normal controls serum VEGF values increased markedly between 30 and 60 min and remained high, whilst plasma VEGF values were low up to 480 min. Thus, plasma samples are more suitable for the measurement of circulating VEGF. Next, plasma VEGF levels were examined in 44 patients with gastric cancer (8 early, 7 advanced without remote metastasis and 29 metastatic), 13 with colorectal adenoma (2 with focal cancer) and 26 with colorectal carcinoma (8 advanced without metastasis and 18 metastatic) before treatment. An extremely high plasma concentration of VEGF was seen in some cancer patients with metastasis. To discriminate these patients, a cut-off level was determined, considering both the distribution of the sample concentration and the upper limit of 95% confidence area of VEGF in the cancer patients without metastasis. The cut-off value was 108 pg/ml and most cancer patients without metastases had VEGF levels below the cut-off value. In 11 of 29 metastatic gastric cancer patients (38%) and 9 of 18 metastatic colorectal cancer patients (50%), plasma VEGF levels were higher than the cut-off value. Survival was also analysed in the patients with metastasis. It was significantly longer in the patients with low VEGF levels (below the cut-off) than in those with high VEGF levels (logrank test, P = 0.042). 34 patients with metastasis (19 gastric cancer and 15 colorectal cancer) were treated with systemic chemotherapy, and their pretreatment levels of plasma VEGF and conventional tumour markers (CEA and CA19-9) were evaluated in relation to response. The response to chemotherapy was significantly higher in patients with low VEGF levels (< or = 108 pg/ml) than in those with high VEGF levels (P = 0.047). Such a difference was not observed with CEA/CA19-9. In conclusion, plasma VEGF is a useful marker for tumour metastasis and patient survival, and a possible predictive factor for the response of patients with gastrointestinal cancer to chemotherapy.

Solid phase micro extraction coupled with semi-microcolumn high performance liquid chromatography for the analysis of benzodiazepines in human urine

SPME/semi-microcolumn HPLC (SPME/LC) was investigated to analyze benzodiazepines in human urine samples. SPME conditions such as extraction time, extraction temperature, salt concentration and pH of matrix, flush volume and desorption time were optimized by extracting various drugs from a prepared water matrix. Combination of adding saturated salts to the matrix and controlling pH ranged from neutral to weakly alkaline conditions makes the increase of extraction efficiency. Under optimal condition SPME/LC is more sensitive than direct HPLC analysis without the SPME process. The limits of detection (LODs) was several ppb level and the relative standard deviation (RSD) was < 15% when human urine samples were analyzed by this analytical system. The system is very useful and is enough to assay benzodiazepines in a human urine sample without tedious and complex analytical procedures. In this paper the applicability of SPME/LC to the analysis of benzodiazepines in human urine samples was reported. In addition, the extension to the evaluation of SPME/LC/MS system was also described.

Measurement and evaluation of serum anti-p53 antibody levels in patients with lung cancer at its initial presentation: a prospective study

Anti-p53 antibodies in sera are known to be products of the host immune response to mutated p53 protein, and are present in some patients with various types of cancer. In this study, we measured serum anti-p53 antibody levels in 52 patients with lung cancer and 63 normal volunteers to determine the relationship between anti-p53 antibody level and clinical features of lung cancer patients. Anti-p53 antibody level was measured by an enzyme-linked immunosorbent assay and expressed as an anti-p53 antibody index, defined as the ratio of absorption of serum sample to that of p53-positive serum. The median anti-p53 antibody index was 6.6 for lung cancer patients, and higher than that in normal volunteers (1.7) (P = 0.0000). For lung cancer patients, significant differences in index levels were found by histology (4.3, n = 25, adenocarcinoma vs 8.7, n = 18, squamous cell carcinoma vs 64.8, n = 2, large-cell carcinoma vs 9.8, n = 7, small-cell carcinoma; P = 0.0109). High anti-p53 antibody index levels were observed for both large-cell carcinoma and small-cell carcinoma. When the cut-off level was set at 7.2, determined using the twice 95% specificity level for normal volunteers, the sensitivities of anti-p53 antibodies were 46.1% for all lung cancers, 28.0% for adenocarcinoma, 55.6% for squamous cell carcinoma, 100% for large-cell carcinoma and 71.4% for small-cell carcinoma. However, there were no significant differences in index level by gender, age, smoking index, presence of previous or concomitant cancer or disease stage. Multivariate analysis using a logistic regression model demonstrated that histological type of tumour was a dominant factor associated with elevation of anti-p53 antibody index level (P = 0.0184). These findings suggest that serum anti-p53 antibody index level might be independent of tumour burden and the presence of previous or concomitant cancer in our series of lung cancer patients, but is clearly strongly correlated with tumour histological type.

Circulating vascular endothelial growth factor (VEGF) is a possible tumor marker for metastasis in human hepatocellular carcinoma

Vascular endothelial growth factor (VEGF) is closely related to angiogenesis in various human cancers. However, little is known of its circulating levels in hepatocellular carcinoma (HCC). We examined circulating VEGF levels in chronic liver disease to assess their clinical significance. Plasma VEGF concentrations were determined, by enzyme immunoassay, in patients with chronic hepatitis (CH; n = 36), liver cirrhosis (LC; n = 77), and HCC (n = 86) for a cross-sectional study. Plasma VEGF levels in healthy controls (n = 20) and CH, LC, and HCC patients were 17.7 +/- 5.4 (mean +/- SD), 30.6 +/- 22.8, 34.4 +/- 27.0, and 51.1 +/- 71.9 pg/ml, respectively. The levels were significantly elevated in the HCC group, compared with the control, CH, and LC groups. Plasma VEGF levels in stage I, II, III, IVA, and IVB HCC patients were 27.6 +/- 16.1, 26.5 +/- 13.7, 35.8 +/- 15.3, 45.4 +/- 39.4, and 103.1 +/- 123.2 pg/ml, respectively. The stage IVB patients with remote metastasis showed significantly marked elevation compared with the patients at the other stages. Platelet numbers were weakly correlated with plasma VEGF levels in the HCC group. Plasma VEGF level was highly elevated in patients with HCC, particularly those with metastatic disease. We consider that plasma VEGF is a possible tumor marker for metastasis of HCC. Circulating VEGF may be derived mainly from the large burden of tumor cells, and partly from platelets activated by the vascular invasion of HCC cells.

Separation of benzodiazepines using cholesterol-modified fused-silica capillaries in capillary electrochromatography

This paper describes the use of cholesteryl-10-undecenoate as a capillary column modifier for capillary electrochromatography. This bonded phase has shown an entirely different selectivity as compared to octadecyl silica (ODS) phases in reversed-phase liquid chromatography, specifically in the analysis of the benzodiazepines. This difference serves as the basis for the continuing study as well as the present focus on electrochromatography as a relatively new separation technique. To significantly increase the surface area, etching of the inner wall of a 75-micron capillary is performed using ammonium hydrogen difluoride and is then subsequently modified via a silation reaction with triethoxysilane and subjected to hydrosilation with cholesteryl-10-undecenoate to form the bonded phase. The performance of this capillary is compared with unetched cholesterol-modified and bare, fused-silica capillaries. Efficient resolution was noted for the etched capillary showing the effectiveness of the etching process as well as the selective property of the bonded phase.

Capillary electrophoretic separation of structurally similar solutes in noncross-linked poly(acrylamide-co-N-isopropylacrylamide) solution

Noncross-linked acrylamide (AA)-N-isopropylacrylamide (IPAAm) copolymers have been used as a buffer additive in capillary electrophoretic separation of structurally similar small solutes. Seven kinds of barbiturates and five kinds of dansylated (Dns) amino acids, which have different hydrophobic side chains, were separated on poly(AA-co-IPAAm)-filled columns and on AA polymer-filled columns under the condition of totally eliminating the contribution of electroosmotic flow (EOF). It is known that the copolymer containing IPAAm has thermosensitive properties, and the hydrophobicity of its surface changes with surrounding temperature. In this investigation, therefore, the effects of an isopropyl group in the copolymer on the electrophoretic separation of the small solutes were studied by comparing the two polymer-filled columns at ambient temperature and at elevated temperature. Although slight differences in migration behavior were observed at ambient temperature between the columns filled with these two polymer solutions, obvious differences in the separation of the solutes were observed at elevated temperature. The observed changes on the migration behavior might be caused by the interaction between copolymer chains exhibiting hydrophobic property and the solute.

[Histological effect of arterial embolization chemotherapy for metastatic liver tumors from colorectal cancer--report of cases of hepatectomy after arterial embolization chemotherapy]

To evaluate the histological effect of arterial embolization chemotherapy (AEC) for the metastatic liver tumors from colorectal cancer, 5 lesions were examined in 4 patients who were treated with surgery after AEC. In addition, to compare the histological changes of the metastatic liver tumors, we histologically examined 7 lesions in 5 patients who were treated with surgery alone as a historical control. For the patients with AEC, anti-cancer agents and lipiodol were administered by selected hepatic arterial infusion with fragments of sponzel. In a group of AEC, all metastatic liver tumors were detected after resection of the primary tumors. The range of tumor size in these lesions was from 2.5 to 4.2 cm in diameter. Otherwise, in a group of non-AEC, the size of tumors ranged from 2 to 5 cm in diameter. In angiography, tumor stainings were detected in 2 lesions, and in all lesions no accumulation of lipiodol was detected by CT scan. The overall response rate at the surgery was 7 to 33% (average 23%) in a group of AEC. In addition, in 2 lesions, about 60% of the lesions were necrotic tissues, and more than 90% of the tumor lesions in 3 lesions were histologically necrosis. Within these lesions, encapsulation of the metastatic tumors was observed in 3 lesions. Otherwise, in a group of non-AEC, 50-70% of the tumor lesions were histologically detected as necrosis, and in one lesion, encapsulation was observed. These evidences suggest the histological effect of AEC may be evaluated when more than 70% of tumor necrosis in lesions is observed. In conclusion, the treatment was effective in 3 cases and not effective in one case.

Serum concentrations of cortisone and cortisol in premature infants

To determine the relationship between biological active cortisol and its inert metabolite cortisone accurately in premature infants, serum cortisone and cortisol concentrations were measured by reversed-phase high-performance liquid chromatography (HPLC) in a group of 232 premature infants and in a control group of 127 children and 88 adults. In the control group, serum cortisone concentrations were greater than serum cortisol levels during the first 2 months after birth; cortisol levels were higher than cortisone levels after 2 months of age. However, in premature infants, serum cortisone concentrations were greater than serum cortisol levels even after the first 2 months, and total concentrations of cortisone and cortisol were equal to those in controls. Results were then analyzed according to the equivalent gestational age of premature infants. Cortisone was predominant in premature infants older than 32 weeks of equivalent gestational age, but cortisol was higher than cortisone from equivalent gestational age 24 to 31 weeks. These findings suggest that the ability of premature infants to secrete glucocorticoids resembled that of normal controls. Also, the fetal zone of the cortex, which is associated with a predominance of cortisone, remained functional in premature infants for a longer time than in control infants. Our findings that in premature infants cortisone was predominant compared with cortisol and the sum of cortisone and cortisol was equal to that in the controls indicate that cortisone cannot be disregarded whenever the cortisol level is estimated, although cortisone itself is recognized to be biologically inactive. Simultaneous measurement of serum cortisone and cortisol concentrations is important when adrenocortical function is being determined, especially in premature infants.

Prospective and randomized trial of lipiodol-transcatheter arterial chemoembolization for treatment of hepatocellular carcinoma: a comparison of epirubicin and doxorubicin (second cooperative study). The Cooperative Study Group for Liver Cancer Treatment of Japan

A randomized, controlled clinical trial was conducted to compare the use of epirubicin (EPI) and doxorubicin (DOX) in Lipiodol (Laboratoire Guerbet, Roissy-Charles-de-Gaulle Cedex, France)-transcatheter arterial chemoembolization as a treatment of hepatocellular carcinoma. One hundred ninety-two hospitals participated, and 415 patients were enrolled in the study during the period between October 1989 and December 1990. The patients were randomly allocated to group A (EPI) or group B (DOX) by a centralized telephone registration. The actual doses of EPI and DOX were 72 mg/body and 48 mg/body, respectively. The 1-, 2-, and 3-year survival rates were, respectively, 69%, 44%, and 33% for group A and 73%, 54%, and 37% for group B. There were no statistically significant differences (P = .2296, log-rank test). When each group of patients was classified retrospectively into high-risk and low-risk subgroups based on the severity index calculated by the Cox regression model from the significant prognostic factors (the pretreatment tumor size, the pretreatment serum alpha-fetoprotein level, tumor encroachment, and Child's classification), the survival curve of the low-risk DOX subgroup was significantly superior to that of the low-risk EPI subgroup (P = .0182). However, there was no significant difference between the high-risk subgroups (P = .4606). The change in the serum alpha-fetoprotein level, the extent of Lipiodol accumulation in the tumor, and the extent of tumor reduction after the treatment did not show any significant differences between the groups. The white blood cell count in group B showed a tendency to decrease slightly more than in group A at 3 weeks after Lipiodol-transcatheter arterial chemoembolization. In conclusion, there was no statistically significant difference between the survival curves of the EPI and DOX groups in Lipiodol-transcatheter arterial embolization treatment of hepatocellular carcinoma.

Measurement of serum p53 protein in patients with small cell lung cancer and results of its clinicopathological evaluation

Serum p53 protein levels were measured in 36 patients with small cell lung cancer (SCLC) and 35 patients with benign lung diseases in order to evaluate the relationship of these levels to clinicopathological features of SCLC. Serum levels of p53 protein were measured by an enzyme-linked immunosorbent assay, p53 protein level was 23.92 +/- 6.78 pg/ml in patients with SCLC, and similar to that (17.47 +/- 2.86 pg/ml) in patients with benign lung diseases. By the clinical stage of SCLC, the mean level of p53 protein was 16.68 +/- 4.62 pg/ml in 21 patients with limited disease, and lower than that in 15 patients with extensive disease (34.05 +/- 14.84 pg/ml) (P = 0.23). The levels of p53 protein were not correlated with age, smoking index, or presence of cancer history for patients with SCLC. However, immunohistochemical examination disclosed a mild correlation between the expression of p53 protein by SCLC tumor and p53 protein serum level (r = 0.45, P = 0.02). Two patients with SCLC had an elevated serum level of p53 protein (> 2 S.D. above the mean for benign lung diseases). However, measurement of p53 protein serum level was not found to be clinically useful for detection of SCLC.

Analysis of toxic drugs by capillary electrophoresis using polyacrylamide-coated columns

Toxic drugs, including barbiturates and benzodiazepines, were analyzed using polyacrylamide-coated columns in capillary electrophoresis (CE). The separations were carried out in absence of electroosmotic flow. Seven kinds of barbiturates were successfully separated with the coated columns in free solution without further additives. Benzodiazepines, the electrically neutral solutes were introduced onto the coated column, and separated in presence of sodium dodecyl sulfate above its critical micelle concentration in the running buffer. This CE method offered fast and efficient separation of more hydrophobic solutes, such as benzodiazepines. The separation of seven barbiturates was studied in linear (noncross-linked) polyacrylamide solutions and in acrylamide/N-isopropylacrylamide (AA/IPAA) copolymer solutions to explore the effect of isopropyl groups in the AA/IPAA copolymer chain.