Ischemic Preconditioning Produces Comparable Protection Against Hepatic Ischemia/Reperfusion Injury Under Isoflurane and Sevoflurane Anesthesia in Rats

BACKGROUND

Various volatile anesthetics and ischemic preconditioning (IP) have been demonstrated to exert protective effect against ischemia/reperfusion (I/R) injury in liver. We aimed to determine whether application of IP under isoflurane and sevoflurane anesthesia would confer protection against hepatic I/R injury in rats.

METHODS

Thirty-eight rats weighing 270 to 300 grams were randomly divided into 2 groups: isoflurane (1.5%) and sevoflurane (2.5%) anesthesia groups. Each group was subdivided into sham (n = 3), non-IP (n = 8; 45 minutes of hepatic ischemia), and IP (n = 8, IP consisting of 10-minute ischemia plus 15-minute reperfusion before prolonged ischemia) groups. The degree of hepatic injury and expressions of B-cell lymphoma 2 (Bcl-2) and caspase 3 were compared at 2 hours after reperfusion.

RESULTS

Hepatic ischemia induced significant degree of I/R injuries in both isoflurane and sevoflurane non-IP groups. In both anesthetic groups, introduction of IP dramatically attenuated I/R injuries as marked by significantly lower aspartate aminotransferase and aminotransferase levels and better histologic grades compared with corresponding non-IP groups. There were 2.3- and 1.7-fold increases in Bcl-2 mRNA levels in isoflurane and sevoflurane IP groups, respectively, compared with corresponding non-IP groups (both P < .05). Caspase 3 level was significantly high in the isoflurane non-IP group compared with the sham group; however, there were no differences among the sevoflurane groups.

CONCLUSIONS

The degree of hepatic I/R injury was significantly high in both isoflurane and sevoflurane groups in rats. However, application of IP significantly protected against I/R injury in both volatile anesthetic groups to similar degrees, and upregulation of Bcl-2 might be an important mechanism.

The relationship between clinical characteristics including presence of exposed lesions and health-related quality of life (HRQoL) in patients with psoriasis: analysis from the nationwide epidemiologic study for psoriasis in Korea (EPI-PSODE study)

BACKGROUND

Psychological aspect and quality of life should be considered in treating patients with psoriasis.

OBJECTIVE

We sought to ascertain which clinical characteristics including presence of exposed lesions are associated with impairment of health-related quality of life (HRQoL) in patients with psoriasis.

METHODS

The EPI-PSODE study was a nationwide, multicenter, cross-sectional study conducted in Korea that included 1260 adult patients with psoriasis. In addition to clinical characteristics including presence of exposed lesions, data were collected using the Psoriatic Arthritis (PsA) Screening and Evaluation (PASE), Dermatology Life Quality Index (DLQI), MOS 36-Item Short-Form Health Survey (SF-36), Work Productivity and Activity Impairment Questionnaire Psoriasis (WPAI: PSO) and Medication Satisfaction Questionnaire (MSQ).

RESULTS

Patients with a DLQI score > 5 (n = 990) were younger, had an earlier onset of psoriasis, scored higher on the Psoriasis Area and Severity Index (PASI), had higher body surface area (BSA) and had higher PASE scores than patients with DLQI ≤ 5 (n = 266). The group of patients with exposed lesions (n = 871) were younger and male predominance, earlier onset of psoriasis, longer disease duration, higher PASI/BSA score and a higher proportion with drinking and smoking history each than the group of patients without exposed lesions (n = 389). Presence of exposed lesions negatively influenced DLQI, 36-Item Short-Form Health Survey (SF-36) (mental component), presenteeism, total work productivity impairment and total activity impairment in the WPAI: PSO. In multiple regression model, PASI score was the only variable which was significantly associated with all HRQoL measures. Presence of exposed lesions was a significant factor affecting DLQI and SF-36 (mental).

CONCLUSION

The presence of exposed lesions has a negative impact on quality of life, mental health and work productivity. Therefore, effective treatments are particularly needed for psoriasis patients with exposed lesions.

Two-year experience of using the measles, mumps and rubella vaccine as intralesional immunotherapy for warts

BACKGROUND

The currently available treatments for warts, including cryosurgery, laser surgery, electrosurgery, and topical keratolytic applications, are often very painful and can induce disfiguring scars. Recently, intralesional immunotherapy with skin test antigens and vaccines has been shown to be effective in the management of warts.

AIMS

To evaluate the efficacy of a new intralesional immunotherapy for warts, using the measles, mumps and rubella (MMR) vaccine.

METHODS

A retrospective study was performed, and we enrolled 136 patients with various types of warts into the study, which was for a duration of 2 years. Patients were treated for a total of six times at 2-week intervals. The treatment response was classified as one of three levels, based on reduction in the size and number of warts, and patients with complete response (CR) were checked for recurrence. Clinical evaluations were carried out using photographs and medical records.

RESULTS

Over half (51.5%) of patients experienced > 50% reduction in the size and number of warts, and 46.7% who had distant warts (in different locations) showed good response. Common warts showed significantly higher treatment response than other types of warts (P < 0.05). However, other clinical variables did not have any effect on efficacy. Almost all the patients reported mild pain during the injection, but other side effects were rarely observed. Only 5.6% of patients who experienced CR had recurrence of warts after 6 months.

CONCLUSIONS

We suggest that intralesional immunotherapy with MMR vaccine is a tolerable and effective method for patients who are sensitive to pain, concerned about side effects, or have common warts. Treatment response is improved by increasing the number of injections.

The influence of patient position on withdrawal force of thoracic epidural catheters

We investigated the forces required to remove thoracic epidural catheters to determine the effect of patient position on removal. Eighty-four patients undergoing open thoracotomy and thoracic patient-controlled epidural analgesia were enrolled. Catheterisation was performed under fluoroscopic guidance before surgery, and the patients were allocated to one of three position groups for removal: prone; sitting; and lateral. On the third postoperative day, the peak tension during withdrawal in the assigned position was measured. No differences in mean (SD) forces were found between groups: prone 1.61 (0.39) N, supine 1.62 (0.61) N and lateral 1.36 (0.56) N (p = 0.140). The withdrawal forces required to remove thoracic epidural catheters were not affected by the position. Thus, the position for removal can be determined by patient's choice and clinical judgement.

Anatomical Analysis of Computed Tomography Images for Determining the Optimal Oblique Fluoroscope Angle for Percutaneous Coeliac Plexus Block

This retrospective study used abdominal computed tomography (CT) scan images to determine the optimal safe oblique angle for fluoroscopy in fluoroscope-assisted coeliac plexus block (CPB). Abdominal CT scans from 131 patients were included in the study: 42 patients with cancer of the pancreas head, 45 with cancer of the pancreas body and tail and 44 with chronic pancreatitis. The oblique angle and entry distance from the midline were measured at the T12 and L1 levels, and the safe angle range that avoided puncture of the organs was also measured. The optimal angle varied between the T12 and L1 levels, and between the right and left sides at the T12 level. There was no difference in the oblique angle between the patient groups. The optimal oblique angle for fluoroscopy was determined to be 17° for right T12, 18° for left T12, and 19° for both left and right L1.

Comparison of femoral arterial blood pressure with radial arterial blood pressure and noninvasive upper arm blood pressure in the reperfusion period during liver transplantation

PURPOSE

The reperfusion period during liver transplantation is hemodynamically unstable. Accurate blood pressure measurements are the mainstay for the efficient management of abrupt cardiovascular changes. We sought to compare femoral arterial blood pressure (FABP) with radial arterial blood pressure (RABP) and noninvasive upper arm blood pressure (NIBP) in the reperfusion period.

METHODS

Thirty-six adult living donor liver recipients were enrolled in this prospective study. Blood pressures in 3 locations were simultaneously recorded from 1 minute before reperfusion to 15 minutes after reperfusion. We evaluated agreements between FABP and RABP and between FABP and NIBP using intraclass correlation coefficients. Also, we investigated the rates of postreperfusion syndrome (PRS) based on the measurements from 3 locations.

RESULTS

After reperfusion, the mean and diastolic RABP agreed more with the corresponding FABP than NIBP. However, systolic NIBP showed high agreement with FABP from 3 to 10 minutes after reperfusion in contrast with the moderate agreement between systolic RABP with FABP, and systolic values of NIBP than RABP were closer to FABP. The rates of PRS based on FABP, RABP, and NIBP measurements were 50.0% (18/36), 80.6% (29/36), and 50.0% (18/36), respectively.

CONCLUSIONS

We believe that NIBP in addition to RABP may be considered to be a reliable alternative when FABP is not available to evaluate hemodynamic instability in the reperfusion period during liver transplantation.

TCDD-up-regulation of IGFBP-6 and IL-5R alpha subunit genes in vivo and in vitro

Although the potent environmental contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) has been well known for its immunosuppressive activity, the mechanisms of its action have been difficult to elucidate. This is partly due to its inability to exert its effects in vitro. To further elucidate the underlying mechanisms of TCDD effects, we screened for genes that are regulated by the in vivo TCDD treatment of mice that are challenged with allogeneic tumor cells. RNA, collected from lymphoid organs including the thymus, draining lymph nodes, and bone marrow, was reverse-transcribed to cDNA and hybridized to DNA arrays that consisted of 588 genes (ClonTech, USA). The expression of the NF-kappaB p65, c-jun, and p27(Kip1) genes was increased by the TCDD treatment, as previously reported. In addition, we found that the expression of several genes, which were not reported as regulated by TCDD, were modulated by TCDD. Some genes, including insulin-like growth factor-binding protein-6 (IGFBP-6) and IL-5R alpha, were upregulated; while other genes, including CD14, were down-regulated. The expression of the IGFBP-6 and IL-5R alpha subunit genes by TCDD in the thymus was confirmed by RT-PCR and Western blot analyses. Furthermore, TCDD effects on the expression of the IGFBP-6 gene was also observed with EL4 mouse thymoma cells. This suggests that IGFBP-6 may be involved in thymic atrophy, and EL4 cells may be used as an in vitro model for studying molecular mechanisms of thymic atrophy.

Engaging the ribosome: universal IFs of translation

Eukaryotic initiation factor 1A (eIF1A) and the GTPase IF2/eIF5B are the only universally conserved translation initiation factors. Recent structural, biochemical and genetic data indicate that these two factors form an evolutionarily conserved structural and functional unit in translation initiation. Based on insights gathered from studies of the translation elongation factor GTPases, we propose that these factors occupy the aminoacyl-tRNA site (A site) on the ribosome, and promote initiator tRNA binding and ribosomal subunit joining. These processes yield a translationally competent ribosome with Met-tRNA in the ribosomal peptidyl-tRNA site (P site), base-paired to the AUG start codon of a mRNA.

Bioavailability and mammary excretion of bisphenol a in Sprague-Dawley rats

This study reports the absolute oral bioavailability and mammary excretion of bisphenol A in rats. The oral bioavailability was determined after administration of relatively low iv (0.1 mg/kg) and oral (10 mg/kg) doses of bisphenol A to rats. After iv injection, serum levels of bisphenol A declined biexponentially, with the mean initial distribution and terminal elimination half-lives being 6.1 +/- 1.3 min and 52.5 +/- 2.4 min, respectively. The systemic clearance (Cls) and the steady-state volume of distribution (Vss) averaged 107.9 +/- 28.7 m/min/kg and 5.6 +/- 2.4 L/kg, respectively. Upon oral administration, the maximum serum concentration (Cmax) and the time to reach the maximum concentration (Tmax) were 14.7 +/- 10.9 ng/ml and 0.2 +/- 0.2 h, respectively. The apparent terminal elimination half-life of bisphenol A (21.3 +/- 7.4 h) after oral administration was significantly longer than that after iv injection, indicating the flip-flop of the absorption and elimination rates. The absolute oral bioavailability of bisphenol A was low (5.3 +/- 2.1%). To determine the extent of mammary excretion, bisphenol A was given by simultaneous iv bolus injection plus infusion to steady state at low, medium, and high doses. The steady-state serum levels of bisphenol A were linearly increased with higher dosing rates. The systemic clearance (mean range, 119.2-154.1 ml/min/kg) remained unaltered over the dosing rate studied. The levels of bisphenol A in milk exceeded those in serum, with the steady-state milk to serum concentration ratio being 2.4-2.7.

Ligand binding profiles of delta-opioid receptor in human cerebral cortex membranes: evidence of delta-opioid receptor heterogeneity

In this study, receptor binding profiles of opioid ligands for subtypes of opioid delta-receptors were examined employing [3H]D-Pen2,D-Pen5-enkephalin ([3H]DPDPE) and [3H]Ile(5,6)-deltorphin II ([3H]Ile-Delt II) in human cerebral cortex membranes. [3H]DPDPE, a representative ligand for delta1 sites, labeled a single population of binding sites with apparent affinity constant (Kd) of 2.72 +/- 0.21 nM and maximal binding capacity (Bmax) value of 20.78 +/- 3.13 fmol/mg protein. Homologous competition curve of [3H]Ile-Delt II, a representative ligand for delta2 sites, was best fit by the one-site model (Kd = 0.82 +/- 0.07 nM). Bmax value (43.65 +/- 2.41 fmol/mg) for [3H]Ile-Delt II was significantly greater than that for [3H]DPDPE. DPDPE, [D-Ala2,D-Leu5]enkephalin (DADLE) and 7-benzylidenaltrexone (BNTX) were more potent in competing for the binding sites of [3H]DPDPE than for those of [3H]Ile-Delt II. On the other hand, deltorphin II (Delt II), [D-Ser2,Leu5,Thr6]enkephalin (DSLET), naltriben (NTB) and naltrindole (NTI) were found to be equipotent in competing for [3H]DPDPE and [3H]Ile-Delt II binding sites. These results indicate that both subtypes of opioid delta-receptors, delta1 and delta2, exist in human cerebral cortex with different ligand binding profiles.

Involvement of acetyl phosphate in the in vivo activation of the response regulator ComA in Bacillus subtilis

Development of genetic competence in Bacillus subtilis is regulated by ComP--ComA, a two-component signal transduction system. The response regulator ComA is primarily activated by ComP, a histidine kinase that mediates response to nutrient conditions and cell density, and the activated ComA is required for transcription of the srf operon, which is essential for the development of genetic competence and surfactin production. In this study we suggested that the ComA could also be activated by a small molecule phospho-donor, acetyl phosphate. Examination of srfA-lacZ expression indicated that a significant amount of srfA expression still occurs in the comP mutant during growth in a sporulation medium containing excess glucose. Analysis of a comP and pta mutant suggests that srfA activation seen in the comP mutant is dependent on the expression of pta, which encodes phosphotransacetylase (Pta). As Pta is responsible for the catalysis for conversion of acetyl coenzyme A to acetyl phosphate, we conclude that the expression of srfA seen in the comP mutant is mainly due to the activation of ComA by acetyl phosphate.

Pharmacological effects of naltriben as a ligand for opioid mu and kappa receptors in rat cerebral cortex

Naltriben (NTB) has been used to differentiate the subtypes of delta opioid receptors, delta1 and delta2. However, there is considerable evidence suggesting that NTB may act on other types of opioid receptors too. We examined the effects of NTB on the specific binding of radiolabeled ligands for opioid mu and kappa2 receptors, and the effects on the release of [3H]norepinephrine ([3H]NE) in rat cerebral cortex slices. NTB displaced the specific binding of [3H]DAMGO with Ki value of 19.79 +/- 1.12 nM in rat cortex membranes. Specific binding of [3H]diprenorphine ([3H]DIP) was inhibited by NTB with Ki value of 82.75 +/- 6.32 nM in the presence of DAMGO and DPDPE. High K+ (15 mM)-stimulated release of [3H]NE was attenuated by DAMGO in rat cerebral cortex slices. NTB (30 nM) shifted the dose-response curve of DAMGO to the right and attenuated the maximal effect. In the meantime, NTB inhibited high K+-stimulated [3H]NE release at concentrations above 100 nM. The inhibitory effect of NTB was not attenuated by CTAP (10 nM) and naloxone (3 nM) but by higher concentration of naloxone (30 nM), nor-BNI (300 nM) and bremazocine (3 nM). These results indicate that NTB, depending on the dosage, could acts not only as an antagonist at delta but also as a noncompetitive antagonist for mu receptors, and as an agonist for kappa2 receptors in rat cerebral cortex.

Pharmacokinetic disposition of polyethylene glycol-modified salmon calcitonins in rats

This study first reports the pharmacokinetic disposition of polyethylene glycol (PEG)-modified salmon calcitonin (sCT) based on the number of attached PEG molecules. PEG-modified sCT was prepared by covalent linkage with succinimidyl carbonate monomethoxy polyethylene glycol. Mono- and di-PEG-sCTs were separated by size exclusion and reverse phase HPLC, and radioiodinated by the chloramine-T method with Na125I. 125I-mono-PEG sCT, 125I-di-PEG-sCT and unmodified 125I-sCT were administered to rats by i.v. injection. Serial blood samples, urine and various tissue samples were taken for the determination of radioactivity. Di-PEG-sCT exhibited significantly reduced systemic clearance (2.3 vs. 11.1 ml/min/kg) and steady-state volume of distribution (229.9 vs. 603.1 ml/kg), while mono-PEG-sCT showed a prolonged elimination half-life (189.1 min vs. 59.8 min) compared with unmodified sCT. The extent of urinary excretion of the PEG-modified sCTs was higher than for the unmodified sCT, but all these chemicals were excreted in urine in small quantities (< or = 0.6%). There was a tendency toward reduced accumulation of PEGylated sCTs in tissues, with its reduction being inversely proportional to the molecular size. Accumulation of the total radioactivity of the unmodified and PEG-modified sCTs was highest in the liver, followed by kidneys, lungs, spleen, heart and thyroid. When expressed per tissue gram weight, however, the highest radioactivity was found in the kidneys. PEGylated sCTs may have greater therapeutic potential via reduced systemic clearance and prolonged elimination half-life over unmodified sCT.

Insulin reverses bupivacaine-induced cardiac depression in dogs

We tested the hypothesis that an insulin infusion would effectively treat bupivacaine-induced cardiac depression in dogs. In 24 mongrel dogs anesthetized with pentobarbital (5 mgkg(-1)h(-1), IV), 0.5% bupivacaine was administrated at a rate of 0.5 mgkg(-1)min(-1) until the mixed venous oxygen saturation decreased to 60% or less. The bupivacaine infusion induced a decrease in mean arterial pressure, cardiac output, and heart rate. The dogs were randomly assigned to one of four groups after the end of bupivacaine infusion. The Control (C, n = 6) and Glucose (G, n = 6) groups received an IV infusion of normal saline (2 mL/kg) and glucose (2 mL/kg of 50% dextrose in water) for 15 min, respectively. The Insulin-Glucose (IG, n = 6) group received an IV bolus of regular insulin (1 U/kg), plus a glucose infusion (2 mL/kg of 50% dextrose in water) for 15 min. The Insulin-Glucose-Potassium (IGK, n = 6) group received the same dose of insulin and glucose as the IG group, plus potassium (1-3 mEqkg(-1)h(-1)). Mean arterial pressure, cardiac output, heart rate, and mixed venous oxygen saturation recovered toward baseline level more rapidly in the IG and IGK groups than in the C group (within 5 min versus more than 20 min). These results suggest that the infusion of insulin and glucose might reverse bupivacaine-induced cardiac depression in dogs.

IMPLICATIONS

We found that insulin and glucose rapidly reversed hemodynamic abnormality in dogs with bupivacaine-induced cardiac depression. This study implies a possible clinical application of insulin treatment for bupivacaine-induced cardiac depression.

Pharmacokinetic disposition and tissue distribution of bisphenol A in rats after intravenous administration

This study examined the dose-linearity pharmacokinetics of bisphenol A, a U.S. Environmental Protection Agency (EPA) classified endocrine disruptor, in rats following iv administration. Upon iv injection of 0.2, 0.5, 1, or 2 mg/kg, serum levels of bisphenol A declined biexponentially, with mean initial distribution and elimination half-life ranges of 4-8.2 min and 38.6-62.2 min, respectively. There were no significant alterations in the systemic clearance rate (mean range 90.1-123.6 ml/min/kg) and the steady-state volume of distribution (mean range 4.6-6.0 L/kg) as a function of the administered dose. In addition, the area under the serum concentration-time curve linearly rose as the dose was increased. In a second study, bisphenol A was given by simultaneous iv bolus injection plus infusion to steady state, and levels were measured in serum and various organs. When expressed in concentration terms (e.g., amount accumulated per gram organ weight), bisphenol A was found predominantly in the lung, followed by kidneys, thyroid, stomach, heart, spleen, testes, liver, and brain. Ratios of the organ to serum bisphenol A concentrations exceeded unity for all the organs examined (ratio range 2.0-5.8) except for brain (ratio 0.75). Given the high systemic clearance and short elimination half-life, bisphenol A is unlikely to accumulate significantly in the rat.

Analysis of tnrA alleles which result in a glucose-resistant sporulation phenotype in Bacillus subtilis

Bacillus subtilis cells cannot sporulate in the presence of catabolites such as glucose. During the analysis of Tn10-generated mutants, we found that deletion of the C-terminal region of the tnrA gene, which encodes a global regulator that positively regulates a number of genes in response to nitrogen limitation, results in a catabolite-resistant sporulation phenotype. Analyses of nrg-lacZ and nasB-lacZ, which are activated by TnrA under nitrogen limitation, showed that C-terminally truncated TnrA activates nitrogen-regulated genes constitutively. The relief of catabolite repression of sporulation may result from the uncontrolled expression of the TnrA-regulated genes.

Cloning of a new Bacillus thuringiensis cry1I-type crystal protein gene

A new cry1I-type gene, cry1Id1, was cloned from a B. thuringiensis isolate, and its nucleotide sequence was determined. The deduced amino acid sequence of Cry1Id1 is 89.7%, 87.2%, and 83.4% identical to the Cry1Ia, Cry1Ib, and Cry1Ic proteins, respectively. The upstream sequence of the cry1Id1 structural gene was not functional as promoter in B. subtilis. The Cry1Id1 protein, purified from recombinant E. coli cells, had a toxicity comparable to that of Cry1Ia against Plutella xylostella, but it was significantly less active than Cry1Ia against Bombyx mori. Cry1Id1 was not active against the coleopteran insect, Agelastica coerulea.

The p53 tumor suppressor stimulates the catalytic activity of human topoisomerase IIalpha by enhancing the rate of ATP hydrolysis

DNA topoisomerase II is an essential nuclear enzyme for proliferation of eukaryotic cells and plays important roles in many aspects of DNA processes. In this report, we have demonstrated that the catalytic activity of topoisomerase IIalpha, as measured by decatenation of kinetoplast DNA and by relaxation of negatively supercoiled DNA, was stimulated approximately 2-3-fold by the tumor suppressor p53 protein. In order to determine the mechanism by which p53 activates the enzyme, the effects of p53 on the topoisomerase IIalpha-mediated DNA cleavage/religation equilibrium were assessed using the prototypical topoisomerase II poison, etoposide. p53 had no effect on the ability of the enzyme to make double-stranded DNA break and religate linear DNA, indicating that the stimulation of the enzyme catalytic activity by p53 was not due to alteration in the formation of covalent cleavable complexes formed between topoisomerase IIalpha and DNA. The effects of p53 on the catalytic inhibition of topoisomerase IIalpha were examined using a specific catalytic inhibitor, ICRF-193, which blocks the ATP hydrolysis step of the enzyme catalytic cycle. Clearly manifested in decatenation and relaxation assays, p53 reduced the catalytic inhibition of topoisomerase IIalpha by ICRF-193. ATP hydrolysis assays revealed that the ATPase activity of topoisomerase IIalpha was specifically enhanced by p53. Immunoprecipitation experiments revealed that p53 physically interacts with topoisomerase IIalpha to form molecular complexes without a double-stranded DNA intermediary in vitro. To investigate whether p53 stimulates the catalytic activity of topoisomerase II in vivo, we expressed wild-type and mutant p53 in Saos-2 osteosarcoma cells lacking functional p53. Wild-type, but not mutant, p53 stimulated topoisomerase II activity in nuclear extract from these transfected cells. Our data propose a new role for p53 to modulate the catalytic activity of topoisomerase IIalpha. Taken together, we suggest that the p53-mediated response of the cell cycle to DNA damage may involve activation of topoisomerase IIalpha.

Absorption, first-pass metabolism, and disposition of itraconazole in rats

This study examined the pharmacokinetic disposition, oral absorption and hepatic extraction of itraconazole and its active metabolite, hydroxyitraconazole, in rats. After i.v. injection, serum itraconazole concentrations decreased biexponentially, with an average terminal elimination half-life, volume of distribution and systemic clearance of 4.9 h, 6.0 l/kg and 14.2 ml/min/kg, respectively. When given orally, its absorption was low, with a mean absolute bioavailability of 16.6%. The metabolite to parent drug area under the curve (AUC) ratio was higher after oral administration compared with i.v. injection (mean ratio, 2.7 vs. 0.9). The hepatic drug extraction ratio determined after femoral and portal vein administration averaged 18.5%. When hydroxyitraconazole was injected i.v., the elimination half-life, volume of distribution and systemic clearance of itraconazole averaged 10.0 h, 2.4 l/kg and 3.4 ml/min/kg, respectively. The fraction of the systemically available itraconazole that was metabolized to hydroxyitraconazole was 21.0% and 76.0% after i.v. and oral administration, respectively. In summary, this study is the first reporting the hepatic extraction of itraconazole and the i.v. disposition characteristics of hydroxyitraconazole in rats. Itraconazole is a drug with a low hepatic extraction ratio and its systemic clearance appears to be largely accounted for by hepatic metabolism.

Usefulness of MR imaging for diseases of the small intestine: comparison with CT

OBJECTIVE

To evaluate the usefulness of MR imaging for diseases of the small intestine, emphasizing a comparison with CT.

MATERIALS AND METHODS

Thirty-four patients who underwent both CT and MR imaging using FLASH 2D and HASTE sequences were analyzed. All patients had various small bowel diseases with variable association of peritoneal lesions. We compared the detectabilities of CT and MR imaging using different MR pulse sequences. The capability for analyzing the characteristics of small intestinal disease was also compared.

RESULTS

MR imaging was nearly equal to CT for detecting intraluminal or peritoneal masses, lesions in the bowel and mesentery, and small bowel obstruction, but was definitely inferior for detecting omental lesions. The most successful MR imaging sequence was HASTE for demonstrating bowel wall thickening, coronal FLASH 2D for mesenteric lesions, and axial FLASH 2D for omental lesions. MR imaging yielded greater information than CT in six of 12 inflammatory bowel diseases, while it was equal to CT in six of seven neoplasms and inferior in five of seven mesenteric ischemia. In determining the primary causes of 15 intestinal obstructions, MR imaging was correct in 11 (73%) and CT in nine (60%) patients.

CONCLUSION

MR imaging can serve as an alternative diagnostic tool for patients with suspected inflammatory bowel disease, small intestinal neoplasm or obstruction.

Regulation of the Bacillus subtilis phosphotransacetylase gene

The enzyme, phosphotransacetylase (Pta), catalyzes the conversion of acetyl coenzyme A to acetyl phosphate. The putative pta gene of Bacillus subtilis, which had been sequenced as part of the Genome Project, was cloned and overexpressed in Escherichia coli. We confirmed that the gene encodes Pta by measuring the enzymatic activity of the purified protein. Insertional mutagenesis of the pta gene resulted in complete loss of the Pta activity, indicating that B. subtilis contains only one kind of pta gene. Expression of a pta-lacZ fusion was induced in the presence of excess glucose in the growth medium, and the intact ccpA gene was required for this activation. The transcriptional start site of the pta gene was located at 37 nucleotides upstream of the pta start codon, and a cre (catabolite responsive element) sequence, a cis-acting element that is responsible for the catabolite repression of a number of carbon utilization genes in B. subtilis, was identified upstream of the tentative promoter site. Experiments involving oligonucleotide-directed mutagenesis showed that the cre sequence is involved in glucose-mediated transcriptional activation.

A role for a highly conserved protein of unknown function in regulation of Bacillus subtilis purA by the purine repressor

Regulation of the purine biosynthetic gene purA was examined by using a transcriptional fusion to a luciferase reporter gene. Transcription was repressed about 10-fold by the addition of adenine and increased approximately 4.5-fold by the addition of guanosine. This regulation is mediated by a purine repressor (PurR). In a purR mutant, basal expression was increased 10-fold, and there was no further stimulation by guanosine or repression by adenine. An open reading frame, yabJ, immediately downstream from purR was found to have a role in the repression of purA by adenine. Repression by adenine was perturbed in a purR+ yabJ mutant, although guanosine regulation was retained. Mutations in the PurR PRPP binding motif abolished guanosine regulation in the yabJ mutant. Thus, PRPP appears to be required for upregulation by guanosine. The amino acid sequence of YabJ is homologous to the YER057c/YjgF protein family of unknown function.

Usefulness of CT in patients with intestinal obstruction who have undergone abdominal surgery for malignancy

OBJECTIVE

The purpose of this study was to evaluate the usefulness of CT in determining the causes of intestinal obstruction in patients who have undergone abdominal surgery for malignancy.

MATERIALS AND METHODS

We analyzed the CT scans of 55 patients with benign (n = 26) or malignant (n = 29) intestinal obstruction that developed after abdominal surgery for malignancy. After calculating the diagnostic accuracy of interpretations by three radiologists, we compared CT findings for benign and malignant intestinal obstructions with respect to peritoneal involvement patterns and other ancillary findings. Multivariate logistic regression analysis was used to determine the diagnostic performance of CT in revealing causes of obstruction.

RESULTS

Diagnostic accuracies of the three radiologists were 67%, 75%, and 78%. CT findings indicating malignant obstruction were a mass at the site of obstruction or prior surgery, lymphadenopathy, or an abrupt transition zone and irregular bowel wall thickening at obstructed sites (p < .05). Conversely, the chance for benign obstruction increased when CT revealed mesenteric vascular changes, a large amount of ascites, or a smooth transition zone and smooth bowel wall thickening at the obstructed site (p < .05). With multivariate logistic regression analysis using two variables (a mass at the site of obstruction or prior surgery and lymphadenopathy), we calculated the overall accuracy of CT as 84% (46/55 patients).

CONCLUSION

CT is useful in differentiating benign from malignant intestinal obstructions in patients who have undergone abdominal surgery for malignancy. However, CT has limitations in patients not having a demonstrable peritoneal mass.

Sequence analysis of the Bacillus subtilis 168 chromosome region between the sspC and odhA loci (184 degrees-180 degrees)

The nucleotide sequence of 45,389 bp in the 184 degrees-180 degrees region of the Bacillus subtilis chromosome, containing the cge cluster, which is controlled by the sporulation regulatory protein GerE, was determined. Fifty-four putative ORFs with putative ribosome-binding sites were recognized. Seven of them correspond to previously characterized genes: cgeB, cgeA, cgeC, cgeD, cgeE, ctpA, and odhA. The deduced products of 25 ORFs were found to display significant similarities to proteins in the data banks. We have identified genes involved in detoxification, cell walls, and in the metabolism of biotins, purines, fatty acids, carbohydrates and amino acids. The remaining 22 ORFs showed no similarity to known proteins. Both an attachment site of the SPbeta prophage and 2 new putative DNA replication terminators were identified in this region.

An 8 kb nucleotide sequence at the 3' flanking region of the sspC gene (184 degrees) on the Bacillus subtilis 168 chromosome containing an intein and an intron

As part of the Bacillus subtilis genome sequencing project, we determined the complete nucleotide sequence of an 8000-bp fragment downstream of the sspC gene (184 degrees) of the B. subtilis 168 chromosome. The sequence analysis shows that the sspC gene is located inside of the SP beta region, which differs from the current genetic map of B. subtilis 168. This region contains 12 putative ORFs (yojQ through yojZ and sspC). A homology search for the deduced products of the ORFs shows significant similarities to enzymes involved in deoxyribonucleotide metabolism: ribonucleotide reductase (Nrd) E, NrdF, thioredoxin and dUTPase. Interestingly, this DNA fragment includes two split genes, yojP containing conserved motifs of an intein and yojQ and yojS with an 808-bp intervening sequence for a putative intron structure. In addition, the yojR gene includes a putative new DNA replication terminator.

Vasculature in hepatocellular carcinoma after transcatheter arterial chemoembolization: comparison of power and color Doppler sonography

The purpose of this study was to compare power Doppler sonography with conventional color Doppler sonography for the detection of the vascularity of hepatocellular carcinomas after transcatheter arterial chemoembolization. Of the 93 embolized hepatocellular carcinomas, hypervascularity was demonstrated in 36 on angiography; power Doppler sonography correctly identified pulsatile flow signals in 33 (92%) of these 36, whereas color Doppler sonography identified flow signals in 24 (67%). A statistically significant difference was noted when the sizes of the nodules were 30 mm or less. Despite technical difficulties, such as flash artifact, power Doppler sonography is superior to color Doppler sonography for detection of hypervascularity, especially in small embolized nodules of hepatocellular carcinoma (30 mm or less in diameter).

Interaction of Bacillus subtilis purine repressor with DNA

A purine repressor (PurR) mediates adenine nucleotide-dependent regulation of transcription initiation of the Bacillus subtilis pur operon. This repressor has been purified for the first time, and binding to control site DNA was characterized. PurR binds in vitro to four operons. Apparent Kd values for binding were 7 nM for the pur operon, 8 nM for purA, 13 nM for purR, and 44 nM for the pyr operon. In each case, DNase I footprints exhibited a pattern of protected and hypersensitive sites that extended over more than 60 bp. A GAAC-N24-GTTC sequence in the pur operon was necessary but not sufficient for the PurR-DNA interaction. However, this motif, which is conserved in the four binding sites, was not required for binding of PurR to purA. Thus, the common DNA recognition element for binding of PurR to the four operons is not known. Multiple PurR-pur operon DNA complexes having a binding stoichiometry that was either approximately two or six repressor molecules per DNA fragment were detected. The results of a torsional constraint experiment suggest that control site DNA forms one right-handed turn around PurR.

The complete genome sequence of the gram-positive bacterium Bacillus subtilis

Bacillus subtilis is the best-characterized member of the Gram-positive bacteria. Its genome of 4,214,810 base pairs comprises 4,100 protein-coding genes. Of these protein-coding genes, 53% are represented once, while a quarter of the genome corresponds to several gene families that have been greatly expanded by gene duplication, the largest family containing 77 putative ATP-binding transport proteins. In addition, a large proportion of the genetic capacity is devoted to the utilization of a variety of carbon sources, including many plant-derived molecules. The identification of five signal peptidase genes, as well as several genes for components of the secretion apparatus, is important given the capacity of Bacillus strains to secrete large amounts of industrially important enzymes. Many of the genes are involved in the synthesis of secondary metabolites, including antibiotics, that are more typically associated with Streptomyces species. The genome contains at least ten prophages or remnants of prophages, indicating that bacteriophage infection has played an important evolutionary role in horizontal gene transfer, in particular in the propagation of bacterial pathogenesis.

Cross-resistance of the diamondback moth indicates altered interactions with domain II of Bacillus thuringiensis toxins

We compared responses to six insecticidal crystal proteins from Bacillus thuringiensis by a Cry1A-resistant strain (NO-QA) and a susceptible strain (LAB-P) of the diamondback moth, Plutella xylostella. The resistant strain showed > 100-fold cross-resistance to Cry1J and to H04, a hybrid with domains I and II of Cry1Ab and domain III or Cry1C. Cross-resistance was sixfold to Cry1Bb and threefold to Cry1D. The potency of Cry1I did not differ significantly between the resistant and susceptible strains. Cry2B did not kill resistant or susceptible larvae. By combining these new data with previously published results, we classified responses to 14 insecticidal crystal proteins by strains NO-QA and LAB-P. NO-QA showed high levels of resistance to Cry1Aa, Cry1Ab, and Cry1Ac and high levels of cross-resistance to Cry1F, Cry1J, and H04. Cross-resistance was low or nil to Cry1Ba, Cry1Bb, Cry1C, Cry1D, Cry1I, and Cry2A. Cry1E and Cry2B showed little or no toxicity to susceptible or resistant larvae. In dendrograms based on levels of amino acid sequence similarity among proteins, Cry1F and Cry1J clustered together with Cry1A proteins for domain II, but not for domain I or III. High levels of cross-resistance to Cry1Ab-Cry1C hybrid H04 show that although Cry1C is toxic to NO-QA, domain III or Cry1C is not sufficient to restore toxicity when it is combined with domains I and II of Cry1Ab. Thus, diamondback moth strain NO-QA cross-resistance extends beyond the Cry1A family of proteins to at least two other families that exhibit high levels of amino sequence similarity with Cry1A in domain II (Cry1F and Cry1J) and to a protein that is identical to Cry1Ab in domain II (H04). The results of this study imply that resistance to Cry1A alters interactions between the insect and domain II.

Cloning of a novel crystal protein gene cry1K from Bacillus thuringiensis subsp. morrisoni

A novel crystal protein gene cry1K has been cloned and sequenced from a Bacillus thuringiensis subsp. morrisoni BF190 isolated from phylloplane. The upstream promoter region of cry1K was almost identical with that of cry1B. The deduced amino acid sequence of Cry1K contains 1215 amino acid residues with an estimated molecular mass of 137 kDa. Comparison of the amino acid sequence of the Cry1K with that of Cry proteins revealed that Cry1K is most closely related to Cry1B and Cry1I. Cry1K has a high degree of identity with Cry1B in the region between initiator codon and conserved sequence block 1, and with Cry1F in the region between conserved block 3 and 5. Protein inclusion purified from a recombinant strain of B. thuringiensis expressing the cry1K gene was found to have a different insect-host specificity from Cry1B, Cry1I and Cry1F, Cry1K was found to be selectively toxic to Artogeia rapae and not active to Plutella xylostella.

Distribution of cryV-type insecticidal protein genes in Bacillus thuringiensis and cloning of cryV-type genes from Bacillus thuringiensis subsp. kurstaki and Bacillus thuringiensis subsp. entomocidus

DNA dot blot hybridizations with a cryV-specific probe and a cryI-specific probe were performed to screen 24 Bacillus thuringiensis strains for their cryV-type (lepidopteran- and coleopteran-specific) and cryI-type (lepidopteran-specific) insecticidal crystal protein gene contents, respectively. The cryV-specific probe hybridized to 12 of the B. thuringiensis strains examined. Most of the cryV-positive strains also hybridized to the cryI-specific probe, indicating that the cryV genes are closely related to cryI genes. Two cryV-type genes, cryV1 and cryV465, were cloned from B. thuringiensis subsp. kurstaki HD-1 and B. thuringiensis subsp. entomocidus BP465, respectively, and their nucleotide sequences were determined. The CryV1 protein was toxic to Plutella xylostella and Bombyx mori, whereas the CryV465 protein was toxic only to Plutella xylostella.