Characterization and subcellular localization of KCNQ1 with a heterozygous mutation in the C terminus

Numerous mutations in KCNQ1, a gene encoding the alpha -subunit of cardiac delayed rectifier potassium channels, have been found in long QT syndrome (LQTS). Among them, several mutations in the C terminus have been shown to cause autosomal recessive or subclinical autosomal dominant LQTS. Here, we report a heterozygous mutation, T587M, which is also in the KCNQ1 C-terminal domain. The same mutation was found in three independent probands that were clearly symptomatic with family history of cardiac sudden death. Functional assay using a heterologous expression system with a mammalian cell line (COS7 cells) revealed that the mutant displayed neither functional channels when expressed alone nor dominant-negative effect when co-expressed with wild-type (WT) KCNQ1. To examine the cellular trafficking of KCNQ1, green fluorescent protein (GFP) was tagged to the cytoplasmic C terminus of WT or mutant KCNQ1. This procedure did not affect the essential properties of expressed WT KCNQ1 channels. On confocal microscopic images, GFP-tagged WT KCNQ1 showed a plasma membrane fluorescence pattern, whereas the GFP-tagged mutant showed a perinuclear fluorescence pattern. Co-expression of the mutant with GFP-tagged WT KCNQ1 did not influence its normal cellular transport. Therefore, the T587M mutant cannot traffic to the plasma membrane and may form no subunit assembly with WT KCNQ1. These findings provide a novel molecular basis for the clinical finding that this C-terminal mutation produced a severe form of RWS-type LQTS.

Pharmacokinetic interaction of cytochrome P450 3A-related compounds with rhodamine 123, a P-glycoprotein substrate, in rats pretreated with dexamethasone

The effect of pretreatment with dexamethasone (DEX) on drug-drug interactions between rhodamine 123 (Rho123), a P-glycoprotein (P-gp) substrate, and midazolam, a cytochrome P450 (CYP) 3A substrate, or verapamil, a P-gp/CYP3A substrate, was studied in rats. Rats were pretreated with DEX (100 mg/kg/day, oral) for 2 days. Western blot analysis with a monoclonal antibody for P-gp, C219, revealed that DEX pretreatment increased P-gp level in the intestine 1.9-fold, but not in the liver. In vitro metabolism study of erythromycin in microsomal suspensions indicated the 9.7-fold increase of CYP3A activity in the liver, but not in the intestine, by DEX pretreatment. In an in vivo study, DEX pretreatment increased P-gp-mediated exsorption clearance of Rho123 from blood to the intestinal lumen approximately 2-fold, but not biliary clearances, in good agreement with the results of Western blot analysis. In untreated rats, midazolam (100 microM) or verapamil (30 or 100 microM) added in the intestinal perfusate (single perfusion) decreased the exsorption clearance and biliary clearance of Rho123 by approximately 30 to 50%. In DEX-pretreated rats, however, the inhibitory potency of midazolam in the liver significantly decreased compared with that in untreated rats, although the potency in the intestine did not change. The inhibitory potency of verapamil decreased both in the intestine and liver by DEX pretreatment. In conclusion, it was demonstrated that DEX pretreatment affects not only P-gp-mediated disposition of Rho123 but also pharmacokinetic interactions of P-gp/CYP3A-related compounds with Rho123, probably because concentrations of substrates/inhibitors at target sites such as the intestine and liver are varied.

[The trend of the drug eruptions in the last fifteen years]

The drug eruptions are known to often become more severe by the readministration of causative drugs. It is an important theme to prevent the relapse of the drug eruptions. We have been monitoring drug adverse reactions at our hospital since October, 1980. We divided fifteen years from October, 1980 to September, 1995 into three periods; the first period (Oct., 1980-Sep. 1985), the second period (Oct., 1985-Sep., 1990), and the third period (Oct., 1990-Sep., 1995), and discussed the trend of the drug eruptions appeared among these three periods. The number of the drug eruptions increased. But the proportion to the total drug adverse reactions and to the number of patients slightly decreased. The eruptions in women much increased and in the patients of forties or older generations also increased. But in patients of thirties or younger generations decreased. While nonsteroidal anti-inflammatory drugs (NSAIDs) other than pyrines, antibiotics other than penicillins and cephalosporins and drugs affecting the cardiovascular system and the metabolism tend to increase, pyrines, penicillins, iodic and biliary contrast media tend to decrease. The incubation period before the eruption appeared is less than three days in most antibiotics and anti-inflammatory drugs. But it is more than four days in most drugs for chronic diseases. Other symptoms such as nausea, fever and liver dysfunction were shown in 9.2% of the drug eruptions. In 8.9% of the drug eruptions a relapse of allergic reactions included eruptions were also found. In some cases the drug eruptions exacerbate by re-administration of beta-lactam antibiotics. In the case of administration of drugs, it is necessary to pay attention to dermatitis caused by the drugs. And we recognized the importance of the system for the prevention of the relapse of drug eruptions including injections.

Evaluation of environmental dose at JCO using luminescence from quartz stimulated by blue light

The environmental dose due to the recent nuclear accident at JCO, Japan, was estimated using luminescence optically stimulated from unheated quartz. Two methods originally developed for dating analysis, the single aliquot additive dose method and the single aliquot regeneration added dose method, were employed to confirm the dose rate. Consistent results were obtained from both methods and from thermoluminescence measurements. Although the dose rate values had lower precision than can be obtained from heated materials, it is suggested that luminescence from sedimentary quartz can usefully be employed in retrosepective dosimetry.

Effects of light and darkness on cell deaths in damaged retinal ganglion cells of the carp retina

Effects of light and darkness on the apoptosis of retinal ganglion cells (RGCs) in young carp were measured by TUNEL method after transection of the optic nerve. Following the operation, the fish were kept under one of four regimens; constant darkness (DD), constant light (LL), 12 hr light and 12 hr dark (LD) and 3 hr of flickering light followed by 21 hr in the dark (FL). On day 3, the highest ratio of apoptotic RGCs was seen under conditions of DD, followed by LL, LD, and FL. On day 6, the percentages of apoptotic RGCs were lower under every experimental condition than what they had been earlier on day 3, but the same ranking order was maintained. Immunohistochemically it could be shown that phosphorylated ERKs were more intensively localized in FL rather than DD retinas. The results suggest that illumination regimens, and in particular cyclic diurnal light/dark changes, have an influence on the degree of apoptosis of damaged RGCs, and that inhibition of apoptosis is correlated with the higher expression of phosphorylated ERKs.

Alteration of the membrane lipid environment by L-palmitoylcarnitine modulates K(ATP) channels in guinea-pig ventricular myocytes

Sarcolemmal adenosine 5'-triphosphate-sensitive K+ channels (K(ATP)) are dramatically up-regulated by a membrane phospholipid, phosphatidyl-inositol-4,5-bisphosphate (PIP2). During ischaemia, L-palmitoylcarnitine (L-PC), a fatty acid metabolite, accumulates in the sarcolemma and deranges the membrane lipid environment. We therefore investigated whether alteration of the membrane lipid environment by L-PC modulates the K(ATP) channel activity in inside-out patches from guinea-pig ventricular myocytes. L-PC (1 microM) inhibited KATP channel activity, without affecting the single channel conductance, through interaction with Kir6.2. L-PC simultaneously enhanced the ATP sensitivity of the channel [concentration for half-maximal inhibition (IC50) fell from 62.0+/-2.7 to 30.3+/-5.5 microM]. In contrast, PIP2 attenuated the ATP sensitivity (IC50 343.6+/-54.4 microM) and restored Ca2+-induced inactivation of KATP channels (94.1+/-13.7% of the control current immediately before the Ca2+-induced inactivation). Pretreatment of the patch membrane with 1 microM L-PC, however, reduced the magnitude of the PIP2-induced recovery to 22.7+/-6.3% of the control (P<0.01 vs. 94.1+/-13.7% in the absence of L-PC). Conversely, after the PIP2-induced recovery, L-PC's inhibitory action was attenuated, but L-PC partly reversed the PIP2-mediated decrease in the ATP sensitivity (IC50 fell from 310+/-19.2 to 93.1+/-9.8 microM). Thus, interaction between L-PC and PIP2 in the plasma membrane appears to regulate K(ATP) channels.

Angiotensin II type 1 receptor blockade abolishes specific K(ATP)channel gene expression in rats with myocardial ischemia

The cardiac ATP-sensitive potassium (K(ATP)) channel is potentially composed of an inward rectifier potassium channel (Kir6.1 and/or Kir6.2) subunit and the cardiac type of sulfonylurea receptor (SUR2A). We reported that cardiac Kir6.1 mRNA and protein are specifically upregulated in the non-ischemic as well as the ischemic regions in rats with myocardial ischemia, suggesting that humoral and/or hemodynamic factors are responsible for this regulation. In the present study, pretreatment with TCV-116, an angiotensin (Ang) II type 1 receptor antagonist, completely inhibited the upregulation of Kir6.1 mRNA and protein expression in both regions of rat hearts subjected to 60 min of coronary artery occlusion followed by 24 h of reperfusion; whereas pretreatment with lisinopril, an Ang converting enzyme (ACE) inhibitor, partly inhibited this upregulation. Except for rats pretreated with TCV-116, Kir6.1 mRNA levels were positively correlated with those for brain natriuretic peptide (BNP), a molecular indicator of regional wall stress, in both the non-ischemic and the ischemic regions. Plasma Ang II levels were not elevated in rats with control myocardial ischemia compared with sham rats. Thus, the stress-related induction of cardiac Kir6.1 mRNA and protein expression under myocardial ischemia is inhibited by pretreatment with an AT1 antagonist, but also in part by an ACE inhibitor, suggesting that activation of local renin-angiotensin system may play a role.

Release characteristics of a short-chain fatty acid, n-butyric acid, from its beta-cyclodextrin ester conjugate in rat biological media

6(A)-O-(n-Butanoyl)-beta-cyclodextrin was prepared and its hydrolysis behavior in aqueous solutions and in rat intestinal fluids was investigated. Furthermore, the enzymatic hydrolyses of the n-butyric acid-beta-cyclodextrin conjugate using alpha-amylase and esterase were studied to gain insight into the release behavior of n-butyric acid from the conjugate. The hydrolysis of the conjugate proceeded according to a first-order kinetics in aqueous solution, and gave a V-shaped pH profile, indicating a specific acid-base-catalyzed hydrolysis at acidic and neutral-alkaline regions, respectively. The half-lives (t(1/2)) of the conjugate at pH 4.4, 6.8, and 7.4 at 37 degrees C were approximately 580, 43, and 6 days, respectively, indicating that the conjugate is stable in aqueous solution. No appreciable release of n-butyric acid from the conjugate was observed in the stomach and small intestinal contents of rats, or in the small and large intestinal homogenates of rats. On the other hand, a fast disappearance of the conjugate and an appearance of n-butyric acid were observed in the cecal and colonic contents of rats. The t(1/2) values of the disappearance were approximately 4, 1, and 6 h in 10 and 15% cecal contents and 10% colonic contents, respectively, and the appearance of n-butyric acid after 6 h was approximately 10% in the 15% cecal contents. Aspergillus oryzae alpha-amylase hydrolyzed the conjugate to small saccharide conjugates, such as the triose and maltose conjugates, but there was no appreciable release of n-butyric acid. The conjugate was less susceptible to carboxylic esterase (from porcine live), thus releasing no appreciable amounts of n-butyric acid. On the other hand, a fast release of n-butyric acid was observed when the esterase was employed after amylase hydrolysis, suggesting that two types of enzymes, sugar-degrading and ester-hydrolyzing enzymes, are necessary for the release of n-butyric acid from the conjugate in large intestinal contents.

Expression and function of P-glycoprotein in rats with glycerol-induced acute renal failure

The effect of glycerol-induced acute renal failure on P-glycoprotein expression and function was evaluated in rats. The in vivo function of P-glycoprotein was evaluated by measuring renal secretory and biliary clearance and brain distribution of rhodamine 123 (Rho-123), a P-glycoprotein substrate, under a steady-state plasma concentration. In acute renal failure rats, the P-glycoprotein level increased 2.5-fold in the kidney, but not in the liver and brain. In contrast, P-glycoprotein function in these tissues was suppressed. Interestingly, not only the renal but also the biliary clearance of Rho-123 was correlated with the glomerular filtration rate. In Caco-2 cells, plasma from renal failure rats exhibited a greater inhibitory effect on P-glycoprotein-mediated transport of Rho-123 than did plasma from control rats. In conclusion, P-glycoprotein function was systemically suppressed in acute renal failure, even though the level of P-glycoprotein remained unchanged or rather increased. This may be due to the accumulation of some endogenous P-glycoprotein substrates/modulators in the plasma in disease states.

The effects of caffeine on ATP-sensitive K(+) channels in smooth muscle cells from pig urethra

The effects of caffeine on both levcromakalim-induced macroscopic and unitary currents in pig proximal urethra were investigated by the use of patch-clamp techniques (conventional whole-cell configuration and cell-attached configuration). The effects of caffeine were also examined on currents in inside-out patches of COS7 cells expressing carboxy terminus truncated inwardly rectifying K(+) channel (Kir6.2) subunits (i.e. Kir6.2DeltaC36) which form ATP-sensitive K(+) channels (K(ATP) channels). In conventional whole-cell configuration, the levcromakalim (100 microM)-induced inward current (symmetrical 140 mM K(+) conditions) was inhibited by caffeine (> or =1 mM) at a holding potential of -50 mV. In contrast, ryanodine (10 microM) caused no significant inhibitory effect on the gradual decay of the levcromakalim-induced current at -50 mV. The amplitude of the 30 microM levcromakalim-induced current was enhanced by 3-isobutyl-1-methylxanthine (IBMX, 100 microM). In cell-attached configuration, the levcromakalim-induced K(+) channel openings were inhibited by subsequent application of 10 mM caffeine, decreasing the channel open probability at -50 mV. Reverse transcriptase-polymerase chain reaction (RT - PCR) analysis revealed the presence of Kir6.2 transcript in pig urethra. Caffeine (> or =3 mM) inhibited the channel activity of Kir6.2DeltaC36 expressed in COS7 cells (3 mM caffeine, 65+/-6%, n=4; 10 mM caffeine, 29+/-2%, n=4). These results suggest that caffeine can inhibit the activity of K(ATP) channels through a direct blocking effect on the pore-forming Kir subunit.

[Day surgery for anal disease]

Historically, patients with anal diseases treated on a day surgery basis had inadequate cure rates and a high complication rate. After World War II, modern treatment methods were learned from the UK and USA and improved in Japan. However, the improved radical methods were so complex that approximately 2 weeks' hospitalization was needed. Recently, day surgery for various diseases including hemorrhoids has been recommended by the Japanese ministry of Health and Welfare. However, the characteristics of anal anatomy and physiology make the smooth healing of wounds difficult and tend to cause postoperative pain, bleeding, infection, prolonged healing time, etc. To prevent such difficulties, care must be well planned following the critical path of informed consent, careful surgery, postoperative observation, and management at home. However, hospital staff in charge of such surgery are under so much stress that only patients with less severe anal disease without local or systemic complications should be selected for day surgery.

Usefulness of magnetic resonance imaging for diagnosing deep anorectal abscesses

PURPOSE

We evaluated the usefulness of magnetic resonance imaging for the preoperative diagnosis of deep anorectal abscesses.

METHODS

Subjects were 21 patients with deep anorectal abscesses. Deep anorectal abscesses were classified into two types, ischiorectal and pelvirectal, according to their location. Patients were also classified into a single abscess group, which showed either an ischiorectal or pelvirectal abscess, and a double abscess group, which showed both ischiorectal and pelvirectal abscesses. The final diagnosis was made from surgical findings, and the types of deep anorectal abscesses determined by digital examination and magnetic resonance imaging were compared.

RESULTS

Sensitivity of ischiorectal abscesses (20 lesions) with digital examination and magnetic resonance imaging was 75 and 95 percent, respectively, and that of pelvirectal abscesses (10 lesions) with digital examination and magnetic resonance imaging was 60 and 70 percent, respectively. Sensitivity of the magnetic resonance imaging was significantly higher than that of digital examination in ischiorectal abscesses. Diagnostic accuracy of digital examination and magnetic resonance imaging were both 83 percent in the single abscess group (12 patients), whereas in the double abscess group (9 patients) it was 22 and 78 percent, respectively. The rate of accurate diagnosis of magnetic resonance imaging compared with digital examination in the double abscess group was significantly higher than that in the single abscess group.

CONCLUSION

Magnetic resonance imaging was useful for diagnosing and differentiating ischiorectal and pelvirectal abscesses.

Tissue-Specific expression of rat kininogen mRNAs

To characterize the local kallikrein-kinin system, tissue distribution of mRNAs for kininogens, precursor proteins of kinins, such as high-molecular-weight (H-), low-molecular-weight (L-) and T-kininogens, were studied in the rat by means of reverse-transcription polymerase chain reaction (RT-PCR) using a fluorophore Cy5-labeled 5'-primer. High levels of these three kininogen mRNAs were present in the liver. Relatively high levels of H-kininogen mRNA were also detected in the skin, lung, kidney, and testis in a descending order, whereas L-kininogen mRNA was detectable in the lung and brain, but not in the kidney, skin, testis, heart, adrenal gland, or skeletal muscle. T-Kininogen mRNA was present in these tissues, except for skeletal muscle. These findings suggest that the expression of each kininogen mRNA is regulated by the tissue-dependent mechanisms which is closely associated with functions of the kallikrein-kinin system in the tissue.

Anti-Candida activity of a new platinum derivative

A new platinum derivative of the form H[Pt(IV)(Hdigly)Cl(2)(OH)(2)] (Hdigly==glycylglycine) damaged the Candida albicans cell membrane and inhibited the growth of the cells. The cytotoxic activity of H[Pt(IV)(Hdigly)Cl(2)(OH)(2)] on mammalian cells was 10-fold lower than that of cis-diammine-dichloroplatinum (cisplatin). Substitution of platinum for peptides is effective for enhancement of antifungal activity and reduction of the toxicity to mammalian cells.

Preparation of novel synthons, uniquely functionalized tetrahydrofuran and tetrahydropyran derivatives

The dianion of the acetoacetic ester reacts with epibromohydrin derivatives to afford a mixture of (Z)-2-alkoxycarbonylmethylidenetetrahydrofuran derivative and (E)-2-alkoxycarbonylmethylidenetetrahydropyran derivative. The selective formation of the tetrahydrofuran derivative is achieved by the use of LiClO4 as the additive. The preparation of the optically active tetrahydrofuran derivatives and tetrahydropyran derivatives is also examined, and the optical purity and absolute configuration of the products is elucidated.

Evaluation of pelvic descent disorders by dynamic contrast roentgenography

PURPOSE

For precise diagnosis and rational treatment of the increasing number of patients with descent of intrapelvic organ(s) and anatomic plane(s), dynamic contrast roentgenography of multiple intrapelvic organs and planes is described.

METHODS

Sixty-six patients, consisting of 11 males, with a mean age (+/- standard deviation) of 65.6+/-14.2 years and with chief complaints of intrapelvic organ and perineal descent or defecation problems, were examined in this study. Dynamic contrast roentgenography was obtained by opacifying the ileum, urinary bladder, vagina, rectum, and the perineum. Films were taken at both squeeze and strain phases. On the films the lowest points of each organ and plane were plotted, and the distances from the standard line drawn at the upper surface of the sacrum were measured. The values were corrected to percentages according to the height of the sacrococcygeal bone of each patient. From these corrected values, organ or plane descents at strain and squeeze were diagnosed and graphically demonstrated as a descentgram in each patient.

RESULTS

Among 17 cases with subjective symptoms of bladder descent, 9 cases (52.9 percent) showed roentgenographic descent. By the same token, among the cases with subjective feeling of descent of the vagina, uterus, peritoneum, perineum, rectum, and anus, roentgenographic descent was confirmed in 15 of 20 (75 percent), 7 of 9 (77.8 percent), 6 of 16 (37.5 percent), 33 of 33 (100 percent), 25 of 37 (67.6 percent), and 22 of 36 (61.6 percent), respectively. The descentgrams were divided into three patterns: anorectal descent type, female genital descent type, and total organ descent type.

CONCLUSIONS

Dynamic contrast roentgenography and successive descentgraphy of multiple intrapelvic organs and planes are useful for objective diagnosis and rational treatment of patients with descent disorders of the intrapelvic organ(s) and plane(s).

Effect of cisplatin on H+ transport by H+ -ATPase and Na+/H+ exchanger in rat renal brush-border membrane

The effect of the potent anticancer drug cisplatin, cis-diamminedichloroplatinum (II) (CDDP), on H+ -ATPase and Na+/H+ exchanger in rat renal brush-border membrane was examined. To measure H+ transport by vacuolar H+ -ATPase in renal brush-border membrane vesicles, we employed a detergent-dilution procedure, which can reorientate the catalytic domain of H+ -ATPase from an inward-facing configuration to outward-facing one. ATP-driven H+ pump activity decreased markedly in brush-border membrane prepared from rats two days after CDDP administration (5 mg/kg, i.p.). In addition, N-ethylmaleimide and bafilomycin A1 (inhibitors of vacuolar H+ -ATPase)-sensitive ATPase activity also decreased in these rats. The decrease in ATP-driven H+ pump activity was observed even at day 7 after the administration of CDDP. Suppression of ATP-driven H+ pump activity was also observed when brush-border membrane vesicles prepared from normal rats were pretreated with CDDP in vitro. In contrast with H+ -ATPase, the activity of Na+/H+ exchanger, which was determined by measuring acridine orange fluorescence quenching, was not affected by the administration of CDDP. These results provide new insights into CDDP-induced renal tubular dysfunctions, especially such as proximal tubular acidosis and proteinuria.

Enhancement of topical delivery of a lipophilic drug from charged multilamellar liposomes

To enhance the topical delivery of rhodamine B base (Rho), a model lipophilic compound, the electrostatic interaction between the positive and negative components incorporated in the liposomal bilayer was utilized. The higher in vitro permeability to Rho in rat skin was observed with positive and neutral multilamellar liposomal preparations, the former was prepared with phosphatidylcholine (PC) and stearylamine (SA) and the latter with PC alone, than that given as a solution. Negative liposome composed of PC and dicetyl phosphate (DCP) showed lower skin permeability to Rho. To enhance the Rho retention in the skin, the electrostatic interaction between SA and DCP, which was confirmed by in vitro partition study, was utilized. By pretreating the skin surface with SA solution or empty SA liposome, the skin distribution of Rho given as DCP liposome was substantially enhanced, with increase in the PC distribution into the skin. The pretreatment effect of empty SA liposome was also observed in rats in vivo. In conclusion, it was found that negative DCP liposome provides better drug retention in the skin with lower skin permeability, and the topical drug delivery from DCP liposome was further enhanced by the pretreatment of the skin surface with empty SA liposome.

[Comparative genomic hybridization for analysis of chromosomal changes in cisplatin-resistant ovarian cancer]

In our attempt to find characteristic genetic changes in resistant tumors, we screened the whole genome for gene aberrations in 28 primary ovarian cancers, using the comparative genomic hybridization (CGH) method. These cancers included 14 tumors from patients who did not respond to cisplatin-based combination chemotherapy in comparison with 14 tumors from patients who completely responded to the chemotherapy. We found gains in chromosomal region 1q21-q22 and 13q12-q14 to be related to the drug-resistant phenotype in ovarian cancer patients. Several genes encoding transcription factors, oncogenes, cell cycle regulators and regulators of the apoptotic pathway are found to be located on these regions of the chromosomes, and these genes are potential modulators for toxic insults in cancer cells. This is the first report that shows the relationship between certain genomic aberrations and clinical resistance for cisplatin-based chemotherapy in ovarian cancer patients based on the CGH analysis. Present findings suggest that these chromosomal gains may be potential indicators for prediction of resistance in ovarian cancer patients prior to cisplatin-based chemotherapy.

Dural arteriovenous malformations associated with cerebral aneurysms

Only limited information is available concerning dural arteriovenous malformations (AVMs) found in association with cerebral aneurysms. The present report focuses on six such cases, concentrating attention on clinical characteristics and significance. Of a total of 46 dural AVMs encountered over a given period, six (13%) were linked with cerebral aneurysms. Particularly strong associations were noted for dural AVMs in the anterior cranial fossa (three of four cases) and convexity (all of three cases). With dural AVMs in the anterior cranial fossa, subarachnoid haemorrhage is common, so that where this is encountered the possibility of a complicating aneurysm should be considered in order to select an appropriate treatment.

The properties of the Kir6.1-6.2 tandem channel co-expressed with SUR2A

Functional ATP-sensitive K (KATP) channels have an octameric subunit structure with four pore-forming subunits (Kir6.x) and four sulfonylurea receptors (SURx). In the present study, the properties of the heteromeric KATP channel whose pore subunits are composed of Kir6.1 and Kir6.2 were examined using a heterologous expression system. In COS7 cells co-transfected with Kir6.1, Kir6.2 and SUR2A at a ratio of 1:1:2, KATP channels showed various unitary conductances between those of Kir6.1/SUR2A (33.6+/-4.2 pS) and Kir6.2/ SUR2A (67.1+/-1.6 pS). Kir6.1-6.2 tandem protein, constructed by fusing the C-terminus of Kir6.1 to the N-terminus of Kir6.2 with a ten glutamine linker sequence, also formed a channel with an intermediate conductance (58.9+/-1.5 pS). Kir6.2 and Kir6.1-6.2 showed similar sensitivity to ATP4-: half-maximal inhibition (IC50) was obtained at 14.1+/-12.8 microM and 17.6+/-9.6 microM, respectively. In the presence of Mg2+, Kir6. 1-6.2 was significantly less sensitive than Kir6.2 to MgATP (IC50=95.5+/-49.6 microM versus 18.9+/-5.0 microM). These results suggest that Kir6.1 and Kir6.2 are endowed with the potential to form a heteromeric KATP channel, which has a low sensitivity to MgATP.

Crossover from dilute to majority spin freezing in two leg ladder system Sr(Cu,Zn)2O3

Muon spin relaxation has been measured in Sr(Cu1-xZnx)2O3. The results for low Zn concentration x</=0.6% are consistent with freezing of dilute moments, with one Cu spin for each Zn, having approximately 0.5&mgr;(B) frozen moment. A sharp increase of the relaxation rate at T-->0 occurred with increasing x around x approximately 0.8%, accompanied by a change of line shape to that expected in a concentrated magnetic environment. Analyses of the results for x>/=0.8% suggest that the majority of Cu moments participate in spin freezing, yet with a significantly reduced and spatially inhomogeneous moment size having a 1D correlation length xi approximately 6 lattice units, or a 2D correlation area involving approximately 19 Cu spins.

Preoperative determination of several serum tumor markers in patients with primary epithelial ovarian carcinoma

This study was designed to evaluate the clinical significance of the use of preoperative serum tumor markers in primary epithelial ovarian cancer. Subjects comprised 111 patients with primary epithelial ovarian cancer. Lactate dehydrogenase (LDH), alpha-hydroxybutyrate dehydrogenase (HBDH), carcinoembryonic antigen (CEA), CA19-9, tissue polypeptide antigen (TPA), CA125 and sialyl TN (STN) serum levels were measured within 7 days before surgery. The tumor marker values were compared with the histopathologic diagnosis. The overall agreement between the test results and the actual outcome was calculated using Student's t test and analysis of variance (ANOVA). Survival curves were constructed according to the Kaplan-Meier method, and differences in survival were assessed with the log-rank test. The prognostic significance of tumor markers for survival was assessed in a multivariate analysis with the Cox proportional hazards model. Of the tumor markers examined in this study, CA125 showed the highest positive rate (77.6%), followed by 63.2% for STN and 55.9% for CA19-9. When the positive rate was compared according to histologic types, serous cystadenocarcinoma, mucinous cystadenocarcinoma, endometrioid adenocarcinoma and clear cell carcinoma showed the highest positive rates for CA125 (94.1%), CA19-9 (76.9%), CA125 (91.7%) and STN (75.0%), respectively. Regarding the distribution of tumor marker levels according to the FIGO stage, LDH, HBDH, TPA and CA125 were correlated with the clinical stage while CEA, CA19-9 and STN did not show any correlation. From analyses of tumor marker levels according to histologic types, all patients with a ratio of CA125 to CEA of >1, 000 had serous cystadenocarcinoma and a ratio of CA125 to CA19-9 of >50 showed serous cystadenocarcinoma or endometrioid adenocarcinoma. On the other hand, all patients with a ratio of LDH or HBDH to CA19-9 of <1.0 had mucinous cystadenocarcinoma or clear cell carcinoma. From univariate analysis, the survival time of patients with elevated CA125, TPA or STN was significantly shorter than that of patients with normal CA125, TPA or STN levels. When the Cox's proportional hazard model was used, we identified age, clinical stage, clear cell carcinoma and serum STN as independent prognostic factors. Serum CA125, TPA or STN may give significant prognostic information in epithelial ovarian carcinoma. It is noteworthy that STN has been identified as an independent prognostic factor and has a high rate of positivity in clear cell carcinoma.

[Midbrain infarction presenting isolated inferior rectus nuclear palsy]

We presented a patient of isolated inferior rectus muscle palsy from midbrain lacunar infarction involving the oculomotor nucleus. The patient noticed sudden onset diplopia gazing to the right side, especially to the right-lower direction. He did not have any other symptom, and neurological examination revealed no other findings. Brain MRI documented the focal hyperintense lesion on T2-weighted images in the right-median midbrain ventral to the aqueduct at the level of the superior colliculus. This lesion involved the right oculomotor nucleus, especially the dorso-lateral subnucleus extend to the inferior rectus muscle. The oculomotor nuclear complex consists of one unpaired subnucleus and four paired subnuclei. Among them, the inferior rectus subnucleus lies dorso-laterally. So nucleus lesion may cause isolated weakness of one of muscles innervated by the oculomotor nerve. Among them the isolated inferior rectus muscle palsy can occur relatively.

Expression of toll-like receptor 2 on gamma delta T cells bearing invariant V gamma 6/V delta 1 induced by Escherichia coli infection in mice

We recently reported that the number of gamma delta T cells was increased after infection with Escherichia coli in C3H/HeN mice. We here showed that an i.p. injection with native lipid A derived from E. coli induced an increase of gamma delta T cells in the peritoneal cavity of LPS-responsive C3H/HeN mice and, albeit to a lesser degree, also in LPS-hyporesponsive C3H/HeJ mice. The purified gamma delta T cells from C3H/HeN and C3H/HeJ mice expressed a canonical TCR repertoire encoded by V gamma 6-J gamma 1/V delta 1-D delta 2-J delta 2 gene segments and proliferated in response to the native lipid A derived from E. coli in a TCR-independent manner. The lipid A-reactive gamma delta T cells bearing canonical V gamma 6/V delta 1 expressed Toll-like receptor (TLR) 2 mRNA, while TLR4 mRNA was undetectable. Treatment with a TLR2 anti-sense oligonucleotide resulted in hyporesponsiveness of the gamma delta T cells to the native lipid A. TLR2-deficient mice showed an impaired increase of the gamma delta T cells following injection of native lipid A. These results suggest that TLR2 is involved in the activation of canonical V gamma 6/V delta 1 T cells by native E. coli lipid A.

Gravimorphogenesis of Cucurbitaceae plants: development of peg cells and graviperception mechanism in cucumber seedlings

We examined the effect of microgravity on the peg formation of cucumber seedlings for clarifying the mechanism of gravimorphogenesis in cucurbitaceous plants. The spaceflight experiments verified that gravity controls the formation of peg, hypocotyl hook and growth orientation of cucumber seedlings. Space-grown cucumber developed a peg on each side of the transition zone of the hypocotyl and root, indicating that on the ground peg formation is regulated negatively by gravity (Takahashi et al. 2000). It was found that the auxin-regulated gene, CS-IAA1, was strongly expressed in the transition zone where peg develops (Fujii et al. 2000). In the seedlings grown horizontally on the ground, CS-IAA1 transcripts were much abundant on the lower side of the transition zone, but no such differential expression of CS-IAA1 was observed in the space-grown cucumber (Kamada et al. 2000). These results imply that gravity plays a role in peg formation through auxin redistribution. By the negative control, peg formation on the upper side of the transition zone in the horizontally growing seedlings might be suppressed due to a reduction in auxin concentration. The threshold theory of auxin concentration accounted for the new concept, negative control of morphogenesis by gravity (Kamada et al. 2000). Anatomical studies have shown that there exists the target cells destined to be a peg and distinguishable at the early stage of the growth. Ultra-structural analysis suggested that endoplasmic reticulum develops well in the cells of the future peg. Furthermore, it was found that reorganization of cortical microtubules is required for the change in cell growth polarity in the process of peg formation. The spaceflight experiment with cucumber seedlings also suggested that in microgravity positive hydrotropic response of roots occurred without interference by gravitropic response (Takahashi et al. 1999b). Thus, this spaceflight experiment together with the ground-based studies has shown that cucumber seedling is an ideal for the study of gravimorphogenesis, hydrotropism and their interaction. Although peg formation is seen specifically in cucurbitaceous seedlings, it involves graviperception, auxin transport and redistribution and cytoskeletal modification for controlling cell growth polarity. This system could be a useful model for studying important current issues in plant biology.

Rice NPH1 homologues, OsNPH1a and OsNPH1b, are differently photoregulated

The members of nonphototropic hypocotyl 1 (NPH1) family of genes in plants are considered to be the blue-light photoreceptors for phototropism. We isolated and characterized two NPH1 homologues from rice named as OsNPH1a and OsNPH1b. The predicted proteins of both OsNPH1 genes include LOV (LOV1 and LOV2) and protein kinase domains which are typically conserved regions in all the members of NPH1 family. Comparison of OsNPH1 apoproteins with those from other plant species revealed a close homology of OsNPHla with Arabidopsis, maize and oat NPH1, while the OsNPH1b appeared to be more closer to the recently found Arabidopsis NPL1. These structural homologies indicate that NPH1 homologues can be grouped into two classes namely "NPH1 type" and "NPL1 type". Northern blot analysis showed that OsNPH1a was strongly expressed in coleoptiles, whereas OsNPH1b was highly expressed in leaves of dark-grown rice seedlings. When the dark-grown seedlings were transferred to the continuous white light, the abundance of the OsNPH1a transcript in coleoptiles rapidly declined to the minimum levels, whereas the OsNPH1b transcript level in leaves gradually increased. These results lead us to conclude that expression of OsNPH1a and OsNPH1b is differently photoregulated in different tissues of rice seedlings.

Interaction of platelet activating factor, reactive oxygen species generated by xanthine oxidase, and leukocytes in the generation of hepatic injury after shock/resuscitation

OBJECTIVE

To evaluate the putative relation of platelet activating factor (PAF), xanthine oxidase, reactive oxidants, and leukocytes in the pathogenesis of hepatic injury after shock/resuscitation (S/R) in vivo.

BACKGROUND

Reactive oxygen metabolites generated by xanthine oxidase at reperfusion have been found to trigger postischemic injury in many organs, including the liver. However, the precise linear sequence of the mechanism of consequent hepatic injury after S/R remains to be characterized.

METHODS

Unheparinized male rats were bled to a mean blood pressure of 45 +/- 3 mmHg. After 2 hours of shock, they were resuscitated by reinfusion of shed blood (anticoagulated with citrate-phosphate-dextrose) and crystalloid and observed for the next 6 or 24 hours.

RESULTS

S/R caused the oxidation of hepatic glutathione and generated centrolobular leukocyte accumulation at 6 hours, followed by predominantly centrolobular hepatocellular injury at 24 hours. Each of these components was attenuated by PAF inhibition with WEB 2170, xanthine oxidase inhibition with allopurinol, antioxidant treatment with N-acetylcysteine, or severe leukopenia induced by vinblastine. In each case, the degree of leukocyte accumulation at 6 hours correlated with the hepatocellular injury seen at 24 hours. However, xanthine oxidase inhibition with allopurinol failed to attenuate further the small level of residual hepatocellular injury seen in leukopenic rats.

CONCLUSION

These findings suggest that reactive oxidants generated by xanthine oxidase at reperfusion, stimulated by PAF, mediate hepatocellular injury by triggering leukocyte accumulation, primarily within the centrolobular sinusoids.

Exploratory study of effective chemotherapy to clear cell carcinoma of the ovary

Although clear cell carcinoma of the ovary is considered to be a tumor with poor prognosis, the clinical characteristics has not been defined. The aim of this study was to evaluate the response of clear cell carcinoma of the ovary to first and second-line chemotherapy and explore effective chemotherapy. Fifty-three patients with clear cell carcinoma of the ovary were enrolled between 1988 and 1997 at our department. Since taxol was not available in Japan at that time, cisplatin-based combination chemotherapy has been exclusively used as a standard first-line chemotherapy. Retrospective analyses of clinical characteristics and the response to first or second-line chemotherapy were performed. Median age was 52 years (range 27-71 years). Tumors were 34% (18/53) stage I, 19% (5/53) stage II, 38% (20/53) stage III, and 9% (5/53) stage IV. All patients with I or II stage disease had optimal cytoreduction. Out of 25 patients with III or IV stage disease 20% (5/25) had negative residual tumor, 36% (9/25) had <2 cm residual tumor, and 44% (11/25) had >/=2 cm residual tumor. All patients received postoperative platinum-based chemotherapy. Of 23 patients with measurable residual tumor 8.7% (2/23) completely and 13% (3/23) partially responded to first-line chemotherapy consisting of cisplatin, adriamycin and cyclophosphamide (CAP) or cisplatin and cyclophosphamide (CP) by CT scan or second look laparotomy. Presence of endometriosis was 55% (29/53) but was not a prognostic factor. Although overall response rate of ovarian clear cell carcinoma to first-line chemotherapy by CAP or CP was about 22%, EP or EJ consisting of etoposide and cisplatin or carboplatin used as a second-line chemotherapy showed 29% response rate, while CPT-P consisting of CPT-11 and cisplatin showed 40% response rate. Clear cell carcinomas were frequently present at early stage, with association of endometriosis and with poor overall prognosis. Although patients with advanced ovarian clear cell carcinoma seemed to have better response to CPT-P than conventional platinum-based chemotherapy, further studies are required with larger number of patients to draw firm conclusions.

63Cu NQR evidence of dimensional crossover to anisotropic 2D regime in S = 1 / 2 three-Leg ladder Sr2Cu3O5

We probed spin-spin correlations up to 725 K with 63Cu nuclear quadrupole resonance in the S = 1 / 2 three-leg ladder Sr2Cu3O5. We present experimental evidence that below 300 K weak interladder coupling causes dimensional crossover of the spin-spin correlation length xi from the quasi-1D (xi approximately 1 / T) to the anisotropic 2D regime ( xi approximately exp2pirho(s) / T, where 2pirho(s) = 290+/-30 K is the effective spin stiffness).

Expression of kininogen, kallikrein and kinin receptor genes by rat cardiomyocytes

To ascertain the existence of the kallikrein-kinin system in the heart, we have studied in vivo and in vitro whether rat cardiac tissue expresses kininogen, kallikrein and kinin receptor mRNAs. The reverse transcription-polymerase chain reaction demonstrated that the ventricular myocardium of adult male rats expressed mRNAs for T- and low-molecular-weight (L-) kininogens, tissue kallikreins such as true kallikrein and T-kininogenase, and bradykinin B2 receptor, but not those for high-molecular-weight kininogen and B1 receptor. Lipopolysaccharide (LPS; 0.5 mg/kg, i.v.) increased the levels of mRNA for T-kininogen at 12 h and the bradykinin B1 receptor at 24 h without affecting that for other components. All of these mRNAs for the kallikrein-kinin system were also detected in cultured cardiomyocytes derived from neonatal rat ventricles; dibutyryl cyclic AMP, LPS or inflammatory cytokines such as interleukin-1 and tumor necrosis factor, up-regulated mRNA expression of T-kininogen, T-kininogenase, or B1 receptor in these cells in vitro. These results suggest that there are two kinin-generating systems in rat myocardium comprising T-kininogen/T-kininogenase and L-kininogen/true kallikrein respectively, and that the former may be relatively important in inflammatory diseases or conditions in which cAMP levels increase in cardiomyocytes.

Relationship between microvessel quantification and inducibility of endogenous tumor necrosis factor in colorectal adenocarcinoma

BACKGROUND

Although we have reported that the inducibility of endogenous tumor necrosis factor (en-TNF) by tumor cells is an independent prognostic factor in Dukes stage C colorectal cancer patients, the mechanism by which the patients having high inducibility of en-TNF show better prognosis is still unclear. We hypothesize that the inducibility of en-TNF by colorectal tumor cells affects the prognosis of patients through the modulation of angiogenesis. Thus, the aim of this study is to clarify the relationship between inducibility of en-TNF and tumor vascularity in colorectal cancer.

PATIENTS AND METHODS

Histological sections from 62 Dukes stage C colorectal cancer patients who received curative operation were immunostained for CD34 antigen. Microvessels were counted in the photograph of x200 fields (0.298 mm2). The average count of five most vascular areas was determined as a microvessel density of each case.

RESULTS

Two of 62 cases were excluded from the analysis, because of insufficient staining. A total of 60 patients were dichotomized by a median vessel count of 34 into two groups: 30 patients with lower microvessel density (Low MVD group) and 30 patients with higher microvessel density (High MVD group). There was no significance in the distribution of all clinicopathological factors among these two groups. Regarding en-TNF inducibility, no difference was shown between the two groups. The five year survival rate of Low MVD group and High MVD group were 58.7% and 68.0%, respectively. And, the 5 year relapse-free survival rate of Low MVD group and High MVD group were 59.7% and 52.2%, respectively. No significant difference was demonstrated between Low MVD group and High MVD group.

CONCLUSION

Intratumoral microvessel density did not influence on the prognosis of colorectal cancer patients in Dukes stage C after curative operation. The inducibility of en-TNF showed no correlation with intratumoral microvessel density in Dukes stage C patients after curative operation.

Takayasu's arteritis in a 69 year-old woman

Takayasu's arteritis and temporal arteritis share many clinical and pathological features. The most discriminatory feature between the two diseases is the age at onset; the mean age at onset of the disease was reported as being 26 years for Takayasu's arteritis and 69 years for temporal arteritis. Here we report a 69-year-old woman who presented with a weak right radial artery pulse. The ethnic background and the presence of vascular insufficiency of the right upper extremity and the absence of clinical signs such as shoulder stiffness and tender scalp indicate that her diagnosis is Takayasu's arteritis. It must be emphasized that the two conditions could be differentiated based on the clinical findings even in a patient as old as 69 years old.

Phospholipase C-linked receptors regulate the ATP-sensitive potassium channel by means of phosphatidylinositol 4,5-bisphosphate metabolism

In the COS7 cells transfected with cDNAs of the Kir6.2, SUR2A, and M(1) muscarinic receptors, we activated the ATP-sensitive potassium (K(ATP)) channel with a K(+) channel opener and recorded the whole-cell K(ATP) current. The K(ATP) current was reversibly inhibited by the stimulation of the M(1) receptor, which is linked to phospholipase C (PLC) by the G(q) protein. The receptor-mediated inhibition was observed even when protein kinase C (PKC) was inhibited by H-7 or by chelating intracellular Ca(2+) with 10 mM 1, 2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetate (BAPTA) included in the pipette solution. However, the receptor-mediated inhibition was blocked by U-73122, a PLC inhibitor. M(1)-receptor stimulation failed to inhibit the K(ATP) current activated by the injection of exogenous phosphatidylinositol 4,5-bisphosphate (PIP(2)) through the whole-cell patch pipette. The receptor-mediated inhibition became irreversible when the replenishment of PIP(2) was blocked by wortmannin (an inhibitor of phosphatidylinositol kinases), or by including adenosine 5'-[beta,gamma-imido]triphosphate (AMPPNP, a nonhydrolyzable ATP analogue) in the pipette solution. In inside-out patch experiments, the ATP sensitivity of the K(ATP) channel was significantly higher when the M(1) receptor in the patch membrane was stimulated by acetylcholine. The stimulatory effect of pinacidil was also attenuated under this condition. We postulate that stimulation of PLC-linked receptors inhibited the K(ATP) channel by increasing the ATP sensitivity, not through PKC activation, but most probably through changing PIP(2) levels.

Embryonal rhabdomyosarcoma of the uterine corpus in a 76-year-old patient

BACKGROUND

Primary embryonal rhabdomyosarcoma of the uterine corpus is an extremely rare tumor. A case of rhabdomyosarcoma originating in the uterine myoma is presented with a review of the literature.

CASE

A 76-year-old female presented with a half-year history of abdominal swelling and fever of unknown origin. A 15 x 15 x 17 cm myoma-like tumor was noted on the anterior wall of the uterine myometrium. The patient underwent total abdominal hysterectomy and bilateral salpingo-oophorectomy. The histology and immunohistochemistry aided in the final diagnosis of a pure embryonal rhabdomyosarcoma of the uterine corpus. This patient received three courses of CYVADIC chemotherapy consisting of cyclophosphamide, vincristine, doxorubicin, and dacarbazine after the surgery and is now alive with no evidence of disease 10 months from her surgery.

CONCLUSION

This case is extremely rare with respect to the uterine corpus origin, especially the myoma nodule and the age of the patient.

Prostaglandin E(1) protects against liver injury induced by Escherichia coli infection via a dominant Th2-like response of liver T cells in mice

Prostaglandin E series (PGEs) are known to protect against lipopolysaccharide (LPS)-induced liver injury by down-regulating the production of inflammatory cytokines. We show here a novel mechanism whereby prostaglandin E(1) protects mice against liver injury after Escherichia coli infection. Prostaglandin E(1) administration suppressed circulating interleukin 12 (IL-12) levels but increased the IL-10 production after E. coli challenge. Furthermore, prostaglandin E(1)-alpha-cyclodextrin (PGE(1)) shifted the Th1/Th2 balance of CD3(intermediate) IL-2Rbeta(+) T cells in the liver to a dominant Th2-like response. Neutralization of endogenous IL-4 by administration of anti-IL-4 monoclonal antibody (mAb) diminished the inhibitory effect of prostaglandin E(1) on liver injury after E. coli challenge. These results suggested that the Th2-like response of liver T cells may be at least partly involved in the mechanism whereby prostaglandin E(1) protects against E. coli-induced liver injury.

Expression of kininogen mRNAs and plasma kallikrein mRNA by cultured neurons, astrocytes and meningeal cells in the rat brain

Expression of kininogen mRNAs has been studied in cultures of three different types of cells in rat brain, including neurons and astrocytes from cerebral cortex and meningeal cells from the leptomeninges/choroid plexus. T-kininogen mRNA was expressed by meningeal cells, but not by neurons and astrocytes, and the expression in meningeal cells was enhanced by culture with prostaglandin E2 (PGE2) or dibutyryl cAMP (Bt2cAMP). Low-molecular-weight kininogen mRNA was not detected in these cultures of cells, even after treatment with PGE2. Although expression of high-molecular-weight kininogen mRNA was very low in these cultures of cells, PGE2 or Bt2cAMP markedly stimulated its expression in cultures of meningeal cells and slightly in neurons, but not in astrocytes. We also found that expression of plasma kallikrein mRNA was strong in cultures of meningeal cells and slight in astrocytes, but absent in neurons. These results suggest that cells in the leptomeninges/choroid plexus are major sources of kininogens in rat brain which may function as precursor proteins for kinins and/or potent cysteine proteinase inhibitors during cerebral inflammation.

The bglA gene of Aspergillus kawachii encodes both extracellular and cell wall-bound beta-glucosidases

We cloned the genomic DNA and cDNA of bglA, which encodes beta-glucosidase in Aspergillus kawachii, based on a partial amino acid sequence of purified cell wall-bound beta-glucosidase CB-1. The nucleotide sequence of the cloned bglA gene revealed a 2,933-bp open reading frame with six introns that encodes an 860-amino-acid protein. Based on the deduced amino acid sequence, we concluded that the bglA gene encodes cell wall-bound beta-glucosidase CB-1. The amino acid sequence exhibited high levels of homology with the amino acid sequences of fungal beta-glucosidases classified in subfamily B. We expressed the bglA cDNA in Saccharomyces cerevisiae and detected the recombinant beta-glucosidase in the periplasm fraction of the recombinant yeast. A. kawachii can produce two extracellular beta-glucosidases (EX-1 and EX-2) in addition to the cell wall-bound beta-glucosidase. A. kawachii in which the bglA gene was disrupted produced none of the three beta-glucosidases, as determined by enzyme assays and a Western blot analysis. Thus, we concluded that the bglA gene encodes both extracellular and cell wall-bound beta-glucosidases in A. kawachii.

Diabetes alters neurite regeneration from mouse retinal explants in culture

We examined the effect of experimental diabetes on neurite regeneration from adult mouse retinal explants cultured in the presence of different concentrations of glucose. The numbers of regenerating neurites at 3, 6 and 10 days in culture at normal glucose concentration (7 mM) were significantly smaller in streptozotocin-induced diabetic C57BL/6 mice than in normal control mice. In contrast, treatment of retinal explants with high glucose concentration (57 mM) significantly diminished the number of regenerating neurites in the control mice, but not in the diabetic mice. These results suggest that retina in diabetic mice has impaired capability of neurite regeneration in a normal glucose environment, but is adaptable to a high glucose environment in vitro.

Galectin-1 regulates initial axonal growth in peripheral nerves after axotomy

The signals that prompt the axons to send out processes in peripheral nerves after axotomy are not well understood. Here, we report that galectin-1 can play an important role in this initial stage. We developed an in vitro nerve regeneration model that allows us to monitor the initial axon and support cell outgrowth from the proximal nerve stump, which is comparable to the initial stages of nerve repair. We isolated a factor secreted from COS1 cells that enhanced axonal regeneration, and we identified the factor as galectin-1. Recombinant human galectin-1 (rhGAL-1) showed the same activity at low concentrations (50 pg/ml) that are two orders of magnitude lower than those of lectin activity. A similarly low concentration was also effective in in vivo experiments of axonal regeneration with migrating reactive Schwann cells to a grafted silicone tube after transection of adult rat peripheral nerve. Moreover, the application of functional anti-rhGAL-1 antibody strongly inhibited the regeneration in vivo as well as in vitro. The same effect of rhGAL-1 was confirmed in crush/freeze experiments of the adult mouse sciatic nerve. Because galectin-1 is expressed in the regenerating sciatic nerves as well as in both sensory neurons and motor neurons, we suggest that galectin-1 may regulate initial repair after axotomy. This high activity of the factor applied under nonreducing conditions suggests that galectin-1 may work as a cytokine, not as a lectin.

Expression of kininogen genes by rat cardiomyocytes

To determine the existence of the kallikrein-kinin system in the heart, we have studied in vitro and in vivo whether rat heart expresses kininogens (KGNs). The reverse transcription-polymerase chain reaction (RT-PCR) for KGN mRNAs demonstrated that the cardiac tissue of adult male rats expresses T-KGN mRNA but not high-molecular-weight (H-) KGN mRNA. An intravenous injection of lipopolysaccharide (LPS) resulted in a significant increase in T-KGN mRNA levels of rat heart within 12 h. Polyacrylamide gel electrophoresis of cDNA products generated by RT-PCR from heart mRNA using primers specific for either T- or low-molecular-weigh (L-) KGN revealed that rat heart expressed not only T-KGN gene but also L-KGN gene, and that LPS injection exclusively stimulated the expression of T-KGN but not of L-KGN gene. T-KGN mRNA was also detected in cultured myocytes derived from fetal rat heart, and the expression was markedly enhanced by an addition of LPS to cultures. These results demonstrated that rat cardiomyocytes are the source of T- and L-KGNs but not of H-KGN, and that their expression of T-KGN mRNA is stimulated by LPS, probably via LPS-receptor CD14.

Foveal retinoschisis and retinal detachment in severely myopic eyes with posterior staphyloma

PURPOSE

To evaluate the tomographic features of the retina in patients with severe myopia and posterior staphyloma.

METHODS

In a prospective study of 32 eyes of 19 consecutive patients with severe myopia and posterior staphyloma, we performed complete ophthalmic examinations and studied cross-sectional images of the macula with optical coherence tomography. Patients' age ranged from 41 to 83 years (average, 62.7 years). Best-corrected visual acuity ranged from 20/500 to 20/40 (average, 20/120). The study included 26 phakic and six pseudophakic eyes. The refractive errors of 26 phakic eyes ranged from -8 to -31 diopters (average, -16.7 diopters). Although refractive errors were within -8 diopters in six pseudophakic eyes, the eyes had apparent posterior staphyloma. The axial lengths measured by A-mode ultrasonography ranged from 25.7 to 32.7 mm (average, 29.2 mm). Slit-lamp examination with contact lens showed that none of the eyes had a macular hole.

RESULTS

In nine eyes with shallow retinal elevation on slit-lamp examination, optical coherence tomography disclosed a foveal retinal detachment with retinoschisis in eight eyes and a foveal retinal detachment in one eye. Two of the remaining 23 eyes had retinoschisis.

CONCLUSIONS

Foveal retinal detachment and retinoschisis are common features in severely myopic eyes with posterior staphyloma. Retinal detachment may precede the formation of a macular hole in severely myopic eyes.

Clinical and pathologic predictors of survival in patients with thymoma

OBJECTIVE

To evaluate the Johns Hopkins Hospital experience with 136 thymomas over the past 40 years. This number of patients allowed quantitative estimation of the independent influence of common clinicopathologic risk factors using multivariate analysis.

SUMMARY BACKGROUND DATA

Thymomas vary widely in terms of recurrence and influence on overall survival. Several series have indicated the importance of initial tumor invasion, as well as the extent of surgical resection, as predictors of recurrence and survival after thymoma resection. However, findings have been equivocal when other predictors of prognosis were examined.

METHODS

The authors evaluated 136 patients seen at the Johns Hopkins Hospital between 1957 and 1997 with a pathologic diagnosis of thymoma. Demographic information, clinical staging data, surgical and adjuvant treatment details, and patient follow-up data were obtained from the patient record and from detailed patient or family interviews. Microscopic sections of all 136 patients were reviewed by two pathologists blinded to the clinical data. All data were analyzed by multivariate Cox regression analysis, which allowed the quantification of the independent predictive value of 12 putative clinicopathologic prognostic indicators.

RESULTS

Completeness of follow-up was 99%, 99%, and 98% of eligible patients at 5, 10, and 15 years, respectively. Forty percent of the patients had associated myasthenia gravis and 27% had a secondary primary malignancy. Overall patient survival rates were 71%, 56%, 44%, 38%, and 33% at 5, 10, 15, 20, and 25 years, respectively. Overall, the thymoma-related mortality rate was 14%; the nonthymoma-related mortality rate was 26%. Incomplete resection, preoperative absence of myasthenia gravis, and advanced Lattes/Bernatz pathologic class were found to be independent predictors of poorer overall survival.

CONCLUSIONS

These findings support a policy of aggressive, complete surgical resection of all thymomas when feasible. Thymoma behaves as a rather indolent tumor, with most deaths from causes unrelated to thymoma or its direct treatment. Clinicians should have an increased awareness of the possibility of second primary malignancies in patients with thymoma.

Changes in cell volume induced by ion channel flux in guinea-pig cardiac myocytes

1. The cell width of guinea-pig ventricular myocytes was measured using an optic device during patch-clamp experiments and the relationship between the ion channel flux and changes in cell volume was examined. 2. On superfusing myocytes with 50, 70, 150 and 200% osmotic solutions, the relative cell width changed to 121.1 (n = 4), 110.8 (n = 27), 87.1 (n = 6) and 82.6% (n = 6) of control, respectively. Changes in cell length were less than 2% in these test solutions. 3. The application of 300 nmol/L isoprenaline to myocytes swollen in the 70% hypotonic solution induced a decrease in cell width from 111.2 to 106.2% (n = 13). The application of isoprenaline in the isotonic solution also induced a decrease in cell width to 96.5% in eight of 13 cells. A membrane depolarization of 2-4 mV accompanied the isoprenaline-induced decrease in volume. In the remaining five cells, neither an obvious isoprenaline-induced decrease in volume nor membrane depolarization was observed. Under ruptured whole-cell voltage clamp conditions, the activation of inward isoprenaline-induced Cl- current decreased cell width. 4. Cell width was seen to either decrease or increase when a large outward or inward K+ current, respectively, was induced by shifting the holding potential or by applying 200 mumol/L pinacidil. Under gramicidin-perforated whole-cell clamp conditions, the cell width did not change, even when a large inward K+ current was induced. 5. When the test solution was applied to half of an elongated myocyte by using a micropipette, the cell width increased or decreased in the part exposed to the hypotonic or hypertonic test solutions, respectively. In contrast, in the other half of the elongated myocyte, the cell width responded in the opposite direction. 6. It is concluded that a continuous ionic flux through ion channels is capable of inducing changes in cell volume by generating a localized osmotic gradient across the cardiac sarcolemma.

Characterization of a novel missense mutation in the pore of HERG in a patient with long QT syndrome

INTRODUCTION

A new strategy to elucidate the molecular mechanisms underlying the long QT syndrome (LQTS) is now available with genetic mutational analyses and characterization of ion channel mutations.

METHODS AND RESULTS

In a 26-year-old woman with LQTS, we identified a novel missense mutation in the pore of HERG by using polymerase chain reaction/single-strand conformation polymorphism (PCR/SSCP) and sequencing of her genomic DNA. The mutation resulted in an amino acid substitution of a positively charged lysine for a highly conserved uncharged asparagine at codon 629 (N629K). Whole cell, patch clamp studies were conducted in COS7 cells by transfecting with wild-type (WT) and/or the mutant N629K HERG. The WT HERG produced an I(Kr)-like, E-4031-sensitive conductance with an inward rectification. In contrast, the cells transfected with the N629K HERG did not display any time-dependent current. Cotransfection of WT and N629K HERG (at a ratio of 1:1) produced a significantly smaller conductance when compared with WT HERG (WT 59.9 +/- 7.3 pA/pF [n = 22] vs WT+N629K 5.5 +/- 2.3 pA/pF [n = 11]; P < 0.01), but did not alter K+ ion selectivity and tail current-voltage dependence. Because aprindine hydrochloride was effective in preventing ventricular tachycardias, we also tested the effect of the drug on WT HERG (I(Kr)) and KvLQT1/KCNE1 (I(Ks)) currents expressed in COS7.

CONCLUSION

Functional analyses of a novel missense mutation in the pore of HERG suggest that the mutation causes marked reduction of I(Kr) via a dominant negative effect.

Gains of 1q21-q22 and 13q12-q14 are potential indicators for resistance to cisplatin-based chemotherapy in ovarian cancer patients

The mechanism of drug resistance in ovarian cancer is multifactorial, and accumulation of multiple genetic changes may lead to the drug-resistant phenotype. In our attempt to find characteristic genetic changes in drug-resistant tumors, we screened the whole genome for gene aberrations in 28 primary ovarian cancers using the comparative genomic hybridization method. These cancers included 14 tumors from patients who did not respond to cisplatin-based combination chemotherapy and 14 tumors from patients who had complete response to the chemotherapy. We found gains in chromosomal regions 1q21-q22 and 13q12-q14 to be related to the drug-resistant phenotype in ovarian cancer patients. Several genes encoding transcription factors, oncogenes, cell cycle regulators, and regulators of the apoptotic pathway are located on these regions of the chromosomes, and these genes are potential modulators for toxic insults in cancer cells. This is the first report that shows the relationship between certain genomic aberrations and clinical resistance to cisplatin-based chemotherapy in ovarian cancer patients based on the comparative genomic hybridization analysis. Present findings suggest that these chromosomal gains may be potential indicators for prediction of resistance in ovarian cancer patients before cisplatin-based chemotherapy.