Red cell distribution width predicts time to recurrence in patients with primary non-muscle-invasive bladder cancer and improves the accuracy of the EORTC scoring system

PURPOSE

To investigate the clinical prognostic value of red cell distribution width (RDW) in patients with non-muscle-invasive bladder cancer (NMIBC).

MATERIALS AND METHODS

We retrospectively evaluated 582 consecutive patients with primary NMIBC. The efficacy of preoperative RDW at predicting treatment outcome was assessed. A cut-off point for predicting recurrence was also identified. Uni- and multivariable analyses of time to recurrence (TTR) and progression were conducted. Harrell's concordance index (c-index) was used to evaluate the additive value of RDW to the European Organization of Research and Treatment of Cancer (EORTC) risk scoring model for recurrence.

RESULTS

According to the receiver operating characteristic curve of RDW for recurrence, a RDW ≥ 14.5% was classified as high. In the multivariable analysis, a high RDW could independently predict shorter TTR (subdistribution hazard ratio [SHR]: 2.65, 95% confidence interval [CI]: 1.83-3.84, P < 0.001), irrespective of tumor characteristics. No significant relationship was observed between RDW and time to progression (SHR: 1.75, 95% CI: 0.76-4.08, P = 0.19). Adding binary-coded RDW to the EORTC risk scoring model significantly improved its discriminatory performance in assessing recurrence risk (c-index: 0.62, improvement: 0.052, P < 0.001). High RDW was associated with shorter TTR in patients treated with bacillus Calmette-Guerin in the multivariable analysis (SHR: 2.0, 95% CI: 1.01-3.98, P = 0.047).

CONCLUSIONS

RDW was an independent, significant prognostic factor of TTR in patients with primary NMIBC. Adding RDW to the EORTC risk model significantly improved the model's predictability for tumor recurrence.

Laparoscopic pelvic organ prolapse repair by mesh interposition following radical cystectomy

Introduction

The present study aims to introduce laparoscopic treatment by the interposition of polypropylene mesh for a pelvic organ prolapse in females following radical cystectomy for treating muscle‐invasive bladder carcinoma.

Case presentation

The patients included two women aged 77 and 79 years with symptomatic enterocele following radical cystectomy and ileal conduit urinary diversion. We performed laparoscopic sacrospinous colpopexy using polypropylene and polypropylene/ePTFE composite meshes.

Conclusion

No recurrent prolapse occurred during 26 and 14 months of follow‐up after the operation. No severe perioperative complications were noted. This is a first report on cases of laparoscopic sacrospinous colpopexy for post‐cystectomy pelvic organ prolapse. Our procedure could be safely performed in two patients with post‐cystectomy pelvic organ prolapse.

Two-step technique of early adrenal artery ligation in open adrenalectomy of giant right adrenal pheochromocytomas: Three case reports

Introduction

Surgical manipulation of a pheochromocytoma carries the risk of releasing catecholamines into bloodstream leading to severe intraoperative hypertension.

Case presentation

We present three patients with right adrenal pheochromocytoma over 10 cm diameter: a 40‐year‐old woman, 63‐year‐old man, and 66‐year‐old woman. They were diagnosed by 123I‐MIBG scintigraphy and received preoperative antihypertensive treatment with 16 mg/day of doxazosin. Open adrenalectomy was performed with early right adrenal artery ligation between the inferior vena cava and ventral aorta (Step 1) as well as between the tumor and upper pole of the right kidney (Step 2). There was no severe intraoperative hypertension, and no recurrence was observed over 33 months, postoperatively.

Conclusion

Early adrenal artery ligation may stop tumor blood supply and significantly reduce the catecholamine release. Our technique was thought to be safe and useful for preventing severe intraoperative hypertension in giant right adrenal pheochromocytoma.

Region-specific alteration of histone modification by LSD1 inhibitor conjugated with pyrrole-imidazole polyamide

Epigenome regulates gene expression to determine cell fate, and accumulation of epigenomic aberrations leads to diseases, including cancer. NCD38 inhibits lysine-specific demethylase-1 (LSD1), a histone demethylase targeting H3K4me1 and H3K4me2, but not H3K4me3. In this study, we conjugated NCD38 with a potent small molecule called pyrrole (Py) imidazole (Im) polyamide, to analyze whether targets of the inhibitor could be regulated in a sequence-specific manner. We synthesized two conjugates using β-Ala (β) as a linker, i.e., NCD38-β-β-Py-Py-Py-Py (NCD38-β2P4) recognizing WWWWWW sequence, and NCD38-β-β-Py-Im-Py-Py (NCD38-β2PIPP) recognizing WWCGWW sequence. When RKO cells were treated with NCD38, H3K4me2 levels increased in 103 regions with significant activation of nearby genes (P = 0.03), whereas H3K4me3 levels were not obviously increased. H3K27ac levels were also increased in 458 regions with significant activation of nearby genes (P = 3 × 10-10), and these activated regions frequently included GC-rich sequences, but less frequently included AT-rich sequences (P < 1 × 10-15) or WWCGWW sequences (P = 2 × 10-13). When treated with NCD38-β2P4, 234 regions showed increased H3K27ac levels with significant activation of nearby genes (P = 2 × 10-11), including significantly fewer GC-rich sequences (P < 1 × 10-15) and significantly more AT-rich sequences (P < 1 × 10-15) compared with NCD38 treatment. When treated with NCD38-β2PIPP, 82 regions showed increased H3K27ac levels, including significantly fewer GC-rich sequences (P = 1 × 10-11) and fewer AT-rich sequences (P = 0.005), but significantly more WWCGWW sequences (P = 0.0001) compared with NCD38 treatment. These indicated that target regions of epigenomic inhibitors could be modified in a sequence-specific manner and that conjugation of Py-Im polyamides may be useful for this purpose.

Soft coagulation in partial nephrectomy without renorrhaphy: feasibility of a new technique and early outcomes

OBJECTIVES

To study the feasibility of a new partial nephrectomy technique using soft coagulation without renorrhaphy.

METHODS

Open partial nephrectomy using soft coagulation without renorrhaphy was carried out on 39 consecutive patients with renal tumors. The renal artery was clamped in the initial 23 cases (59%), whereas 16 surgeries (41%) were carried out without clamping. The resected surface of the kidney was coagulated solely by soft coagulation without renorrhaphy. Suturing was used only when the urinary collecting system was opened. The surgical results and perioperative complications were retrospectively evaluated.

RESULTS

The mean age of patients was 63.1 years. The mean tumor size was 28.2 mm (range 10-56 mm). The mean RENAL nephrometry score was 8.03 (range 4-10). The mean cold ischemic time (in clamped cases) was 25 min. The mean operative time was 193 min (range 113-310 min), and the mean estimated total blood loss was 172 mL (range 20-530 mL) in all cases. All operations were uneventful, and none required blood transfusion or conversion to nephrectomy. Postoperative complications, such as hemorrhage, urinary fistula formation and requirement of hemodialysis, were not observed. All patients had negative surgical margins, and were free of disease recurrence during the follow-up period (3-49 months). Overall, a remarkable decrease in renal function was not evident at the end of the follow-up period.

CONCLUSIONS

This new technique using soft coagulation appears to be safe and feasible for partial nephrectomy.

Microfabricated surface-electrode ion trap for scalable quantum information processing

Individual laser-cooled 24Mg+ ions are confined in a linear Paul trap with a novel geometry where gold electrodes are located in a single plane and the ions are trapped 40 microm above this plane. The relatively simple trap design and fabrication procedure are important for large-scale quantum information processing (QIP) using ions. Measured ion motional frequencies are compared to simulations. Measurements of ion recooling after cooling is temporarily suspended yield a heating rate of approximately 5 motional quanta per millisecond for a trap frequency of 2.83 MHz, sufficiently low to be useful for QIP.

Thermally excited modes in a pure electron plasma

Thermally excited plasma modes are observed in near-thermal-equilibrium pure electron plasmas over a temperature range of 0.05<kT<5 eV. The measured thermal emission spectra together with a plasma-antenna coupling calibration uniquely determine the temperature. This calibration is obtained from the spectra themselves when absorption of the receiver-generated noise is significant, or from kinetic theory. This nondestructive temperature diagnostic agrees well with standard diagnostics and may be useful for expensive species such as antimatter.

Frequency and clinical characteristics of dilated cardiomyopathy caused by desmin gene mutation in a Japanese population

AIMS

Dilated cardiomyopathy is partly caused by a mutation of some cytoskeletal or nuclear envelope proteins. It has been confirmed recently that a missense mutation of the gene encoding desmin, a cytoskeletal protein, can cause dilated cardiomyopathy. This study was aimed at elucidating the frequency and clinical characteristics of dilated cardiomyopathy caused by desmin mutation.

METHODS AND RESULTS

We examined 265 Japanese patients with dilated cardiomyopathy (217 sporadic cases and 48 probands of familial dilated cardiomyopathy). The exon 8 of the desmin gene, the critical region for the pathogenesis of dilated cardiomyopathy, was analysed by polymerase chain reaction, single-strand conformation polymorphism and sequencing. The same missense mutation (Ile451Met) as reported previously was detected in three patients (1.1%). All these patients were male and sporadic, and more likely to be accompanied by characteristics such as younger age at diagnosis, lower fractional shortening and ejection fraction than each mean value of sporadic cases. The chronological changes in cardiac function were inconsistent in the three patients.

CONCLUSION

The missense mutation (Ile451Met) of the desmin gene can be the genetic cause of dilated cardiomyopathy, although with very low frequency. The ages at diagnosis were younger and the cardiac function had deteriorated further than general cases of sporadic dilated cardiomyopathy.

Iridium complex-catalyzed allylic amination of allylic esters

Iridium complex-catalyzed allylic amination of allylic carbonates was studied. The solvent strongly affected the catalytic activity. The use of a polar solvent such as EtOH is essential for obtaining the products in high yield. The reaction of (E)-3-substituted-2-propenyl carbonate and 1-substituted-2-propenyl carbonate with pyrrolidine in the presence of a catalytic amount of [Ir(COD)Cl](2) and P(OPh)(3) (P/Ir = 2) gave a branch amine with up to 99% selectivity. Both secondary and primary amines could be used for this reaction. When a primary amine was used, selective monoallylation occurred. No diallylation product was obtained. The reaction of 1,1-disubstituted-2-propenyl acetate with amines exclusively gave an alpha,alpha-disubstituted allylic amine. This reaction provides an alternative route to the addition of an organometallic reagent to ketimines for the preparation of such amines. The reaction of (Z)-3-substituted-2-propenyl carbonate with amines gave (Z)-linear amines with up to 100% selectivity. In all cases, no (E)-linear amine was obtained. The selectivities described here have not been achieved in similar palladium complex-catalyzed reactions.

Non-homologous recombination between Alu and LINE-1 repeats caused a 430-kb deletion in the dystrophin gene: a novel source of genomic instability

Although large deletions in the dystrophin gene have been identified in more than two-thirds of Duchenne and Becker muscular dystrophy patients, the molecular mechanisms that lead to the generation of these deletions are largely unknown. Here, Alu and LINE-1 (L1) repetitive elements were shown to be present at one or other of the two ends, respectively, of a 430-kb deletion in the dystrophin gene. The breakpoint of the deletion, which stretches from exons 2 to 7, was defined more precisely by polymerase chain reaction (PCR) walking on introns 1 and 7. Finally, the region containing the breakpoint was amplified as a fragment of more than 10kb. Sequencing of the deletion endpoint revealed the presence of an Alu sequence in intron 1, 25 kb downstream from the 3' end of exon 1 that was joined directly to an L1 sequence in intron 7, 4.5kb downstream from the 3' end of exon 7. The deletion was calculated to be 430kb. To our knowledge, this is a novel recombination event joining non-homologous Alu and L1 repeats, and is the largest known intrachromosomal deletion that is thought to involve repetitive genetic elements. Sequence characteristics around the breakpoint are discussed.

Carvedilol improves endothelium-dependent dilatation in patients with coronary artery disease

OBJECTIVE

Flow-mediated, endothelium-dependent dilatation (FMD) of the coronary and peripheral circulation is impaired by increased oxidative stress in patients with coronary artery disease (CAD). Carvedilol is a novel beta-blocker that also shows an antioxidant effect in vitro. However, the effect of carvedilol on endothelial dysfunction associated with established coronary atherosclerosis has not been examined in the clinical setting.

METHODS

We studied 29 patients with CAD, including 17 with recent myocardial infarction and 12 with stable effort angina pectoris. Nineteen patients received carvedilol (10 with infarction and 9 with angina), and 10 were treated with placebo (7 with infarction and 3 with angina). We also studied 13 age- and sex-matched control subjects. Brachial FMD during reactive hyperemia and nitroglycerin-induced, endothelium-independent dilatation were assessed by high-resolution ultrasound.

RESULTS

FMD was smaller in patients with CAD compared with controls, although nitroglycerin-induced dilatation was similar. Carvedilol significantly improved FMD after long-term treatment (5. 1% +/- 0.4% at baseline to 7.8% +/- 0.3% after 4 months; P <.01) but not after short-term treatment (5.1% +/- 0.4% at baseline to 5.0% +/- 0.7% after 2 hours). Placebo therapy had no effect on endothelial dysfunction. Neither carvedilol nor placebo had an effect on nitroglycerin-induced dilatation after short- and long-term treatment. Long-term carvedilol therapy also significantly decreased the plasma level of thiobarbituric acid-reactive substances compared with placebo (carvedilol, 5.8 +/- 0.4 nmol/mL to 4.6 +/- 0.3 nmol/mL, P <.01; placebo, 5.9 +/- 0.4 nmol/mL to 5.8 +/- 0.4 nmol/mL, P = not significant).

CONCLUSION

These findings suggest that the improvement of endothelial function by carvedilol may be caused by its antioxidant activity.

[Mutations of the dystrophin gene in dilated cardiomyopathy]

X-linked dilated cardiomyopathy(XLDCM) is caused by mutations of the dystrophin gene, which was originally cloned as the responsible gene for Duchenne muscular dystrophy and Becker muscular dystrophy. Mutations due to XLDCM are centered on 5' end of the gene, especially M-promoter and the adjacent region. However, other mutations are dispersed and cannot be characterized. Three mechanisms have been proposed by which the involvement of cardiac muscle is so severe in spite of the lack of skeletal muscle symptoms; 1) up-regulation of B- and P-dystrophin in merely skeletal muscle compensating for the defect of M-dystrophin, 2) dysfunction of some parts of dystrophin specifically essential to cardiac muscle, 3) different expression patterns of mutant mRNA between cardiac and skeletal muscle.

Systemic endothelial function is preserved in men with both active and inactive variant angina pectoris

To test the hypothesis that coronary spasm could be a coronary manifestation of systemic endothelial dysfunction and that the activity of coronary spasm could influence systemic endothelial function, we examined brachial flow-mediated, endothelium-dependent vasodilation and nitroglycerin-induced endothelium-independent vasodilation with high-resolution ultrasound in 11 men with variant angina pectoris (6 active and 5 inactive) without established coronary atherosclerosis. Endothelium-dependent vasodilation in peripheral circulation was preserved in men with active and inactive variant angina pectoris, suggesting that systemic endothelial dysfunction is not involved in either the pathogenesis or the activity of coronary spasm.

Mutational analysis of the cardiac actin gene in familial and sporadic dilated cardiomyopathy

Dilated cardiomyopathy (DCM) results in part from genetic disorders. Recently, missense mutations of the cardiac actin gene have been reported to cause DCM. We studied 136 Japanese DCM cases to elucidate how frequently the gene mutations are involved in its pathogenesis. Genomic DNA samples were obtained from 136 DCM cases (107 males, 29 females), containing 30 familial DCM (5 confirmed and 25 suspected). All six exons of the cardiac actin gene were analyzed by polymerase chain reaction, single-strand conformation polymorphism, and sequencing. We detected no mutations of the disease causation previously reported (G867A or A1014G) but two silent mutations (G979C and C1018T) in exon 6 and one point mutation (T1080A) in the 3'-untranslated region. As a result of screening 128 healthy subjects, these novel silent mutations were found to be mere genetic polymorphisms, not responsible for the disease. Although some genetic polymorphisms exist in the cardiac actin gene, mutations of the gene are rarely responsible for DCM, at least in the Japanese patients.

Disruption of the splicing enhancer sequence within exon 27 of the dystrophin gene by a nonsense mutation induces partial skipping of the exon and is responsible for Becker muscular dystrophy

The mechanism of exon skipping induced by nonsense mutations has not been well elucidated. We now report results of in vitro splicing studies which disclosed that a particular example of exon skipping is due to disruption of a splicing enhancer sequence located within the exon. A nonsense mutation (E1211X) due to a G to T transversion at the 28th nucleotide of exon 27 (G3839T) was identified in the dystrophin gene of a Japanese Becker muscular dystrophy case. Partial skipping of the exon resulted in the production of truncated dystrophin mRNA, although the consensus sequences for splicing at both ends of exon 27 were unaltered. To determine how E1211X induced exon 27 skipping, the splicing enhancer activity of purine-rich region within exon 27 was examined in an in vitro splicing system using chimeric doublesex gene pre-mRNA. The mutant sequence containing G3839T abolished splicing enhancer activity of the wild-type purine-rich sequence for the upstream intron in this chimeric pre-mRNA. An artificial polypurine oligonucleotide mimicking the purine-rich sequence of exon 27 also showed enhancer activity that was suppressed by the introduction of a T nucleotide. Furthermore, the splicing enhancer activity was more markedly inhibited when a nonsense codon was created by the inserted T residue. This is the first evidence that partial skipping of an exon harboring a nonsense mutation is due to disruption of a splicing enhancer sequence.

[Analysis of processes of elevating calcaneum bone stiffness in young women--from the view point of their life-style]

Calcaneum bone stiffness in 222 young women was investigated by using an ultra-sound bone densitometer (Achilles). Their exercise experiences, amounts of dairy products (including foods which contain a lot of calcium) consumed and 24 questions on their eating attitudes were also analysed. Stiffness showed a significant (p < 0.05) positive correlation with age, BMI and the onset of menarche by polynomial (2) regressions. Using these three variables, expected stiffness was calculated by multiple regression, and according to the differences between the real and expected stiffness, the subjects were divided into three subgroups. Group H which showed higher stiffness, showed significantly (p < 0.05) higher exercise experiences and had the habit of consuming more dairy products and small fish than the other two groups. In all of the subjects, the most important variable which increased the stiffness was the exercise experience at junior high school and the next was the habit of eating small fish. The subjects who customarily ate their meals with their families were more likely to eat small fish. These findings suggest that family eating habits should be noticed not only in post-menopausal women, but also in young girls.

A rare case of severe acute pancreatitis complicated with pancreatic pseudocysts, obstructive jaundice and intraperitoneal hemorrhage

A 58-year-old man visited our hospital because of back pain. Blood examinations revealed the presence of acute inflammation and an increase of pancreatic enzymes. Abdominal computed tomography indicated pseudocysts in the pancreas. The patient was diagnosed as having acute pancreatitis with pseudocysts formation. During the course of the disease, a newly formed pseudocyst in the pancreatic head compressed the common bile duct, leading to the obstructive jaundice. In addition, the rupture of a pseudocyst in the pancreatic tail caused intraperitoneal hemorrhage. This is an interesting case of acute pancreatitis with pseudocysts in which two rare complications developed.

[Mechanism of volume regulation of vestibular dark cells of the gerbil]

The volume response of vestibular dark cells of the gerbil to a hyposmotic challenge was investigated. Tissues including dark cells were perfused in preparations in which the perfusate had access to both sides of the epithelium and the height of the dark cell layer was measured as an indicator of its volume. We found that dark cells showed a fast and strong regulatory volume decrease (RVD) and prevented cell swelling in hypotonic media. This mechanism was dependent upon extracellular [K+] and [Cl-]. Ion selectivity of this mechanism was K+ = Rb+ > Cs+ > Na+ = NMDG+ (N-methyl-D-glucamine) for cations and Cl- = SCN- = NO3- > > gluconate- for anions. RVD of dark cells was inhibited by K(+)- channel blockers barium, quinidine and lidocaine, by Cl(-)-channel blockers 4-acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic acid and 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid, by an Na(+)-K+ ATPase inhibitor ouabain and by low temperature, but was not inhibited by a loop diuretic bumetanide, by carbonic anhydrase inhibitors acetazolamide and ethoxyzolamide, by a K(+)-channel blocker tetraethylammonium, by a Cl(-)-channel blocker 5-nitro-2 (3-phenylpropylamino)-benzoic acid or by an inhibitor of the Na(+)-H+ exchanger amiloride. These data suggest that the RVD of dark cells occurs via separate K+ and Cl- channels which are different from those active under isosmotic condition, and is presumably activated by a hyposmotic stimulus.

Vestibular dark cells contain the Na+/H+ exchanger NHE-1 in the basolateral membrane

Vestibular dark cells and strial marginal cells transport K+ by similar mechanisms. We have shown that K+ transport in vestibular dark cells is sensitive to the cytosolic pH (pHi) (Wangemann et al. (1995a): J. Membrane Biol. 147: 255-262). The present study addresses pharmacologically the questions whether vestibular dark cells and strial marginal cells from the gerbil contain a Na+/H+ exchanger (NHE) and in which membrane, apical or basolateral, NHE is located. Further, the study addresses the question which NHE subtype is present in vestibular dark cells. pHi was measured micro-fluorometrically with the pH-sensitive dye 2',7'-bicarboxyethyl-5(6)-carboxyfluorescein (BCECF), cell volume which is a measure of the net balance between ion influx and efflux was monitored as cell height (CH) and the equivalent short circuit current (Isc) which is a measure of transepithelial K+ secretion was calculated from measurements of the transepithelial voltage (Vt) and the transepithelial resistance (Rt). Changes in pHi were induced by 20 or 40 mM propionate. In the presence of propionate a transient acidification of pHi was observed in vestibular dark cells as well as a subsequent alkalinization to pHi values exceeding those under control conditions. The alkalinization of pHi in the presence of propionate was inhibited by the NHE blockers amiloride and EIPA. Propionate-induced swelling of vestibular dark cells was inhibited by amiloride. The NHE blocker amiloride caused in vestibular dark cells an acidification of pHi and a decrease in CH. Amiloride caused in both vestibular dark cells and strial marginal cells a transient stimulation of Isc when added to the basolateral side but not added to the apical side. Similar effects and pHi were observed in vestibular dark cells with the amiloride analog ethyl-isopropyl-amiloride (EIPA) and similar effects on Isc were observed with EIPA and the NHE blocker HOE694 when applied to the basolateral side of vestibular dark cell epithelium. The IC50 for these basolateral effects of EIPA, HOE694 and amiloride on Isc in vestibular dark cells were 2 x 10(-7) M, 8 x 10(-7) M and 4 x 10(-5) M. These observation suggest that vestibular dark cells and strial marginal cells contain NHE in their basolateral membrane, that K+ transport in strial marginal cells in pHi sensitive similar to K+ transport in vestibular dark cells and that NHE in vestibular dark cells consists of the subtype NHE-1.

Effects of ethanol on meal-stimulated secretion of pancreatic polypeptide and cholecystokinin: comparison of healthy volunteers, heavy drinkers, and patients with chronic pancreatitis

Tiscornia and Dreiling (Physiopathogenic Hypothesis of Alcoholic Pancreatitis: Supranormal Ecbolic Stimulation of the "Pancreon" Units Secondary to the Loss of the Negative Component of Pancreas Innervation. Pancreas 1987;2:604-612.) proposed that hypertonicity of intrapancreatic cholinergic neurons provoked by chronic alcoholism may contribute to the pathogenesis of chronic pancreatitis (CP). In the present study, the validity of this hypothesis was investigated in humans by studying the effects of atropine, cisapride, and ethanol on the meal-stimulated secretion of pancreatic polypeptide (PP) and cholecystokinin (CCK) in healthy volunteers, heavy drinkers, and CP patients. In healthy volunteers, the early phase PP response (0-40 min) to a test meal was completely blocked by atropine, whereas it was augmented by cisapride, an enhancer of acetylcholine release from cholinergic nerves. The early phase PP response to a test meal was inhibited by ethanol in healthy volunteers, whereas, in heavy drinkers, the response was augmented and the inhibition by ethanol was abrogated. In CP patients, ethanol tended to enhance the early phase PP response. Ethanol did not affect the early phase CCK response to a test meal in any group, but it significantly enhanced the late phase CCK response (40-120 min) in CP patients. These results suggest that: (i) oral ethanol may inhibit the postprandial activation of the cholinergic neural pathway to the pancreas in healthy subjects, (ii) in heavy drinkers, postprandial cholinergic tone may be augmented and become resistant to the inhibition by ethanol, and (iii) the ethanol-induced increase in the postprandial CCK response in CP patients may play some role in the pathophysiology of this disease.

Ion selectivity of volume regulatory mechanisms present during a hypoosmotic challenge in vestibular dark cells

Volume regulation during a hypoosmotic challenge (RVD) in vestibular dark cells from the gerbilline inner ear has previously been shown to depend on the presence of cytosolic K+ and Cl-, suggesting that it involves KCl efflux. The aim of the present study was to characterize hypoosmotically-induced KCl transport under conditions where a hypoosmotic challenge causes KCl influx via the pathways normally used for efflux. Net osmolyte movements were monitored as relative changes in cell volume measured as epithelial cell height (CH). A hypoosmotic challenge (298 to 154 mosM) in the presence of 3.6 or 25 mM K+ and loop-diuretics (piretanide or bumetanide) caused an increase in CH by about a factor of 1.2 presumably due to the net effect of primary swelling defined as osmotic dilution of the cytosol and RVD involving KCl efflux. A hypoosmotic challenge in the presence of 79 mM K+ and loop-diuretics, however, caused CH to increase by a factor of over 2.4. Presumably, this large increase in CH was due to the sum of primary and secondary swelling. Secondary swelling depended on the presence of extracellular K+ and Cl- suggesting that it involved KCl influx followed by water. The ion selectivity of secondary swelling was K+ = Rb+ > Cs+ >> Na+ = NMDG+ and Cl- = NO3- = SCN- >> gluconate-. Secondary swelling was not inhibited by Ba2+, tetraethylammonium, quinidine, lidocaine, amiloride, 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid, 4-acetamido-4'-diisothiocyanatostilbene-2,2'-disulfonic acid, 4,4'-dinitrostilbene-2,2'-disulfonic acid, 5-nitro-2(3-phenylpropylamino)benzoic acid, acetazolamide, or ethoxyzolamide. These data define a profile of the hypoosmotically-induced KCl transport pathways. The ion selectivity and the blocker insensitivity are consistent with the involvement of the apical slowly activating K+ channel (IsK or minK channel) and the basolateral 360 pS Cl- channel. The involvement of these channels, however, remains to be demonstrated.

The pH-sensitivity of transepithelial K+ transport in vestibular dark cells

The pH-sensitivity of transepithelial K+ transport was studied in vitro in isolated vestibular dark cell epithelium from the gerbil ampulla. The cytosolic pH (pHi) was measured microfluorometrically with the pH-sensitive dye 2',7'-bicarboxyethyl-5(6)-carboxyfluorescein (BCECF) and the equivalent short-circuit current (Isc), which is a measure for transepithelial K+ secretion, was calculated from measurements of the transepithelial voltage (Vt) and the transepithelial resistance (Rt) in a micro-Ussing chamber. All experiments were conducted in virtually HCO3(-)-free solutions. Under control conditions, pHi was 7.01 +/- 0.04 (n = 18), Vt was 9.1 +/- 0.5 mV, Rt 16.7 +/- 0.09 omega cm2, and Isc was 587 +/- 30 microA/cm2 (n = 49). Addition of 20 mM propionate- caused a biphasic effect involving an initial acidification of pHi, increase in Vt and Isc and decrease in Rt and a subsequent alkalinization of pHi, decrease of Vt and increase of Rt. Removal of propionate- caused a transient effect involving an alkalinization of pHi, a decrease of Vt and Isc and an increase in Rt, pHi in the presence of propionate- exceeded pHi under control conditions. Effects of propionate- on Vt, Rt and Isc were significantly larger when propionate- was applied to the basolateral side rather than to the apical side of the epithelium. The pHi-sensitivity of Isc between pH 6.8 and 7.5 was -1089 microA/(cm2.pH-unit) suggesting that K+ secretion ceases at about pHi 7.6. Acidification of the extracellular pH (pHo) caused an increase of Vt and Isc and a decrease of Rt most likely due to acidification of pHi. Effects were significantly larger when the extracellular acidification was applied to the basolateral side rather than to the apical side of the epithelium. The pHo sensitivity of Isc between pH 7.4 and 6.4 was -155 microA/(cm2.pH unit). These results demonstrate that transepithelial K+ transport is sensitive to pHi and pHo and that vestibular dark cells contain propionate- uptake mechanism. Further, the data suggest that cytosolic acidification activates and that cytosolic alkalinization inactivates the slowly activating K+ channel (IsK) in the apical membrane. Whether the effect of pHi on the IsK channel is a direct or indirect effect remains to be determined.

DIDS increases K+ secretion through an IsK channel in apical membrane of vestibular dark cell epithelium of gerbil

Vestibular dark cell epithelium secretes K+ via IsK channels in the apical membrane. The previous observation that disulfonic stilbenes increased the equivalent short circuit current (Isc) suggested that these agents might be useful investigative tools in this tissue. The present experiments were conducted to determine if the increase in Isc was associated with an increase in K+ flux and if the effect was directly on the IsK channel or indirectly via a cytosolic intermediary. Measurements of transepithelial K+ flux with the K(+)-selective vibrating probe and of changes in net cellular solute flux by measurements of epithelial cell height showed that 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS) increased K+ flux by a factor of 1.96 +/- 0.71 and caused net solute efflux. The apical membrane was partitioned with a macropatch pipette and DIDS was applied either to the membrane outside the pipette, inside the pipette or to the entire apical membrane. DIDS inside the pipette increased the current across the patch, the membrane conductance, the slowly-inactivating (IsK) component of the membrane current and shifted the reversal voltage toward the equilibrium potential for K+. DIDS outside the patch decreased the patch current and conductance, consistent with shunting of current away from the membrane patch. These findings strongly support the notion that DIDS increases K+ secretion through IsK channels in the apical membrane of vestibular dark cell epithelium by acting directly on the channels or on a tightly colocalized membrane component.

[Ruptured distal anterior cerebral artery aneurysms presenting with acute subdural hematoma: report of two cases]

Two cases of ruptured distal anterior cerebral-artery aneurysms presenting with acute subdural hematoma are reported. Case 1 was a 55-year-old male, who showed abrupt disturbance of consciousness. An emergency CT revealed acute subdural hematoma at the right parietal convexity and interhemispheric fissure with moderate midline shift. There was no evidence of subarachnoid hemorrhage. Right carotid angiography showed an aneurysm at the right distal anterior cerebral artery. An emergency external decompression was performed and the aneurysm was clipped successfully through the interhemispheric fissure. In the operative field, subarachnoid hemorrhage could not been seen, and the patient had uneventful recovery. Case 2 was a 66-year-old female, who complained of severe headache. She deteriorated rapidly and become comatous with development of anisocoria. An emergency CT revealed acute subdural hematoma on the bilateral parietal convexities and interhemispheric fissure with severe midline shift. There was no evidence of subarachnoid hemorrhage. Carotid angiography showed right distal anterior cerebral artery aneurysm. An emergency external decompression was performed, then the aneurysm was clipped successfully. She recovered with disorientation and hemiparesis. Ruptured distal anterior cerebral artery aneurysms presenting with acute subdural hematoma without subarachnoid hemorrhage are rare. It is suggested that CT scans and history of patients are most important but an emergency angiography was prerequisite for correct diagnosis. Surgical treatment should be the best management in such cases.

[Evaluation of angiographic delayed vasospasm due to ruptured aneurysm in comparison with cerebral circulation time measured by IA-DSA]

Delayed vasospasm due to ruptured aneurysm has been basically evaluated by angiographic changes in contrast to clinical features such as delayed ischemic neurological deficits (DIND). However, the discrepancies between angiographic and clinical findings have been pointed out. In this study, angiographic changes and cerebral circulation time in ruptured aneurysms were simultaneously investigated with IA-DSA. Thirty-two patients, who had ruptured aneurysms at the anterior circle of Willis and neck clippings at the acute stage, were investigated. Carotid angiogram was performed with IA-DSA on the 7-13th day after the attack. Angiographic changes were evaluated by Fischer's classification and circulation time was calculated in the following way. A time-density curve was obtained at the two ROI's; the C3-C4 portion and the rolandic vein. Circulation time was defined by the difference between the time showing peak optical density at the carotid and the venous portion. The control value of this circulation time obtained from 20 cases with non-rupture aneurysm and epilepsy was 3.4 sec (53 year old) on the average. X-ray CT scan examination was performed at the same time and clinical features were observed everyday. Angiographically, 3 cases were free from vasospasm, 18 cases were found to present slight to moderate vasospasm, and 11 cases showed severe vasospasm. Circulation time in patients with no spasm was 3.6 seconds, in patients with slight to moderate vasospasm it was 4.3 seconds and in patients with severe vasospasm it was 6.8 seconds. Ten patients showing cerebral infarction on CT scans demonstrated significantly long circulation time, 7.0 second on the average.(ABSTRACT TRUNCATED AT 250 WORDS)

Cell volume control in vestibular dark cells during and after a hyposmotic challenge

Cell height was measured as an index of volume in a preparation of vestibular dark cells in which the perfusate had access to both sides of the epithelium. In response to a hyposmotic challenge induced by removal of 75 mM NaCl, cell height increased to 107%; however, cell width did not increase. Significantly larger increases in cell height were observed in the absence of Cl- or K+ or in the presence of ouabain, lidocaine, barium, or quinidine, at 7 degrees C, or after fixation with glutaraldehyde. However, no significantly different swelling was observed during a hyposmotic challenge in the absence of Na+ or in the presence of bumetanide or ethoxyzolamide. Subsequent return to control osmolarity caused a regulatory volume increase that was dependent on Na+, Cl-, and K+, inhibited by bumetanide, ouabain, or 7 degrees C, however not inhibited by ethoxyzolamide, barium, quinidine, or lidocaine. The data suggest that cell volume control during the hyposmotic challenge involved a mechanism dependent on cytosolic KCl and the Na(+)-K(+)-ATPase and that the Na(+)-Cl(-)-K+ cotransporter was involved in regulatory volume increase.

Ba2+ and amiloride uncover or induce a pH-sensitive and a Na+ or non-selective cation conductance in transitional cells of the inner ear

The membrane potential Vm the cytosolic pH (pHi), the transference numbers (t) for K+, Cl- and Na+/non-selective cation (NSC) and the pH-sensitivity of Vm were investigated in transitional cells from the vestibular labyrinth of the gerbil. Vm, pHi, tK+, tCl-, tNa+/NSC, and the pHi sensitivity of Vm were under control conditions were -92 +/- 1 mV (n = 89 cells), pHi 7.13 +/- 0.07 (n = 11 epithelia), 0.87 +/- 0.02 (n = 22), 0.02 +/- 0.01 (n = 19), 0.01 +/- 0.01 (n = 24) and -5 mV/pH unit (n = 13 cells/n = 11 epithelia), respectively. In the presence of 100 mumol/l Ba2+ the corresponding values were: -70 +/- 1 mV (n = 32), pHi 7.16 +/- 0.08 (n = 6), 0.31 +/- 0.05 (n = 4), 0.06 +/- 0.01 (n = 6), 0.20 +/- 0.03 (n = 10) and -16 mV/pH-unit (n = 15/n = 6). In the presence of 500 mumol/l amiloride the corresponding values were: -72 +/- 2 mV (n = 34), pHi 7.00 +/- 0.07 (n = 5), 0.50 +/- 0.04 (n = 6), 0.04 +/- 0.01 (n = 11), 0.28 +/- 0.04 (n = 9) and -26 mV/pH-unit (n = 20/n = 5). In the presence of 20 mmol/l propionate plus amiloride the corresponding values were: -61 +/- 2 mV (n = 27), pHi 6.72 +/- 0.06 (n = 5), 0.30 +/- 0.02 (n = 6), 0.06 +/- 0.01 (n = 5) and 0.40 +/- 0.02 (n = 8), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

The Na+/H+ exchanger in transitional cells of the inner ear

The cytosolic pH (pHi) of transitional cells from the ampulla of the gerbil was measured micro-fluorometrically with the pH-sensitive dye 2',7'-bicarboxyethyl-5(6)-carboxyfluorescein (BCECF) to assess the possible contribution of a Na+/H+ exchanger to the regulation of pHi. All experiments were conducted in virtually HCO3(-)-free solutions. Under control conditions, pHi was 7.19 and addition of 10(-5) M ethylisopropylamiloride (EIPA), a blocker of Na+/H+ exchange, caused a small but significant acidification of pHi. A transient exposure to 21.4 mM NH4Cl caused a rapid cytosolic alkalinization followed by a brisk acidification and prompt recovery of pHi to its control value. The cytosolic buffer capacity (Bi) was determined in the absence of Na+ from changes in pHi which were elicited by [NH4+] steps. Bi was 4.7 mM/pH at pHi 7.19 and varied with pHi. The initial net proton flux JH, representative of Na+/H+ exchange activity, was calculated from the product of the initial rate of alkalinization after an NH4(+)-prepulse and Bi at the corresponding pHi. JH was dependent on the extracellular Na+ with an apparent Km of 64 mM, sensitive to the cytosolic [H+] with an apparent Km of 2.7 * 10(-7) M (i.e. pH 6.6), and inhibited by EIPA with an IC50 of 5 * 10(-7) M. These data suggest that transitional cells contain in the basolateral membrane a Na+/H+ exchanger of the amiloride-sensitive subtype.

Evidence for the involvement of a K+ channel in isosmotic cell shrinking in vestibular dark cells

Cell volume changes were measured in dark cells. Isosmotic addition of 21.4 mM K+, Rb+, Cs+, or NH4+ to a control solution containing 3.6 mM K+ caused piretanide-sensitive cell swelling (initial rate for K+, 0.100 +/- 0.005 microns/s; n = 119), suggesting dependence on the Na(+)-Cl(-)-K+ cotransporter. Subsequent isosmotic removal of 21.4 mM K+ caused piretanide-insensitive cell shrinking (initial rate, -0.104 +/- 0.005 microns/s; n = 119), which was inhibited by barium, lidocaine, quinidine, quinine, verapamil, and 4-aminopyridine but not tetraethylammonium (TEA) or glibenclamide, suggesting the involvement of K+ channel(s). Barium, lidocaine, quinine, quinidine, and 4-aminopyridine caused cell swelling in control solution (initial rate for barium, 0.011 +/- 0.004 microns/s; n = 6), suggesting that the K+ channel is also involved in efflux under control conditions. Cell shrinking was slowed by 21.4 mM extracellular K+, Rb+, or Cs+ but unaffected by Na+, Li+, TEA+, or NH4+ (all in the presence of piretanide and compared with N-methyl-D-glucamine), supporting the notion that the efflux mechanism is permeable to and/or inhibited by K+, Rb+, and Cs+. Cell shrinking was slowed by the presumed replacement of intracellular K+ by Cs+ but not by Rb+. Circumstantial evidence suggests that this putative K+ channel is present in the basolateral membrane. The physiological relevance of such a K+ channel might encompass regulatory volume decrease during K+ secretion.

Effect on cochlear potentials of lateral semicircular canal destruction

Recording of the cochlear potentials was successfully performed during experimental labyrinthectomy in the guinea pig and in three patients with acoustic neuromas during translabyrinthine removal of the tumors. In the guinea pig, complete interruption of the duct of the lateral semicircular canal including the endolymphatic canal caused little change in the endocochlear DC potential of the first cochlear turn and input-output function curve of the N1 component of the compound action potential elicited by 8-kHz tone bursts. Further drilling of the vestibular labyrinth in the guinea pig caused decline of these potentials when the vestibular was opened. In patients with acoustic neuromas, the interruption of the duct of the lateral semicircular canal hardly altered the N1 input-output function curve and N1 input-latency function curve during the 1-hour observation period. Consistent preservation of cochlear function even after interruption of lateral semicircular canals suggests the possibility of partial surgical labryrinthectomy with preservation of hearing for lesions involving semicircular canals.

Effect of perilymphatic air perfusion on cochlear potentials

Perilymphatic fistula is now widely recognized to cause acute profound hearing loss. It is still controversial, however, which mechanism it is that causes the reversible hearing loss. Recently, it has been suggested by two groups of researchers that the intrusion of air bubbles into the perilymphatic space (a condition called pneumolabyrinth or aerolabyrinth) through the ruptured labyrinthine window(s) may be one of the causes. In order to examine the mechanism underlying the hearing loss associated with pneumolabyrinth, the perilymphatic space of the guinea pig cochlea was perfused with air and cochlear potentials were recorded. Although perfusion of the scala tympani with air at a rate as high as 200 microliter/min caused an immediate and drastic decrease of the cochlear microphonics (CM) and the compound action potential (AP), it had little effect on the endocochlear dc potential (EP) during perfusion for 20 min. A decline in EP was seen in half the ears, but only when the duration of perfusion exceeded 30 min. These results show that the EP has an amazing resistance to air trapped in the scala tympani of the cochlea and that the initial decrease of hearing acuity after the elimination of perilymph from the scala tympani (or introduction of air into the scala tympani) is probably due to interference in CM and AP generation mechanisms rather than to strial dysfunction.

[Bilateral simultaneous sudden deafness--a report of five cases]

Five cases of bilateral simultaneous sudden deafness were reported. Two patients were male and three patients were female. The age of the patients ranged from five to 54 years. All the five cases were profoundly deaf on both sides. The elevation of the mumps virus antibody titer was found in the three cases out of four in those examined. The recovery pattern of hearing was seen symmetrically on both sides in four cases. Although complete recovery of hearing was obtained in one case and remarkable improvement was observed in two cases bilaterally, no improvement was seen in one case on either side. The last case showed remarkable improvement of hearing on one side with only a slight recovery on the other. Although the prognosis of the five cases of bilateral simultaneous sudden deafness was found comparable to that of the unilateral case by other investigators, the recovery was slower and the prognosis was less favorable in cases with the elevation of mumps antibody titer.

Residue analysis of triflumizole and its metabolite in crops by high-performance liquid chromatography

A procedure for high-performance liquid chromatographic (HPLC) determination of triflumizole and its metabolite (Met) in crops was examined. Triflumizole and Met in sample crops were extracted with methanol and re-extracted into methylene chloride. After clean-up of the extract on a Florisil column, triflumizole and Met were determined by HPLC with UV detection at 238 nm. The HPLC column was packed with Nucleosil 5 C18 (ODS, 5 micron) and the eluent was acetonitrile-3 mM carbonate buffer (7:3, v/v, pH 9.0). The detection limit was 0.01-0.02 ppm and the recoveries from spiked crops (0.5 ppm) were 73-99% for triflumizole and 74-94% for Met. Triflumizole and Met were determined simultaneously and the method was shown to be applicable to residue analysis of these compounds in crops sprayed with Trifmine in fields.

[Nationwide study of the antimicrobial susceptibility of clinical isolates of Proteus group in Japan]

We discussed the antimicrobial susceptibilities of Proteus group isolated in 1983 and 1984 and also the annual changes of the susceptibilities from 1980 to 1984. The tested strains were isolated in 103 hospitals in Japan. Antibiotics tested for this study were ampicillin (ABPC), cefazolin (CEZ), cefmetazole (CMZ), and gentamicin (GM). The MIC's were determined by the standard method of the Japan Society of Chemotherapy. Susceptibilities of the bacterial strains to the 4 antibiotics were described below: 1. Proteus mirabilis had good susceptibilities to all the antibiotics tested. 2. Susceptibilities of Proteus vulgaris were low to ABPC and CEZ, but high to CMZ and GM. 3. Proteus morganii showed low susceptibilities to ABPC and CEZ, and moderate to CMZ and GM. 4. Susceptibilities of Proteus rettgeri were low to ABPC and CEZ, and 25-40% of the strains were resistant to CMZ and GM. 5. Proteus inconstance had low susceptibilities to ABPC and CEZ, but fairly good to CMZ. About 55% of the strains showed resistance to GM. 6. There were no significant annual changes in susceptibilities of P. mirabilis, P. vulgaris and P. morganii to ABPC, CEZ and CMZ during the period from 1980 to 1984, but decreased susceptibilities to GM were noted in 1982. 7. There was no evidence of changes in susceptibilities of strains of P. rettgeri to ABPC and CMZ, but a tendency of decreasing susceptibilities to CEZ was shown from 1981. 8. P. inconstance showed no major changes in susceptibilities to ABPC, CMZ and GM. 9. Frequencies of resistant strains with MIC of 25 micrograms per ml or more in P. mirabilis, P. morganii and P. rettgeri were higher in 1982 and/or 1983 than the other years.

Simultaneous determination of four active ingredients of dinocap in crops by high-performance liquid chromatography

A procedure for high-performance liquid chromatographic (HPLC) determination of four active ingredients of dinocap, 2,4-dinitro-6-octylphenyl crotonate, 2,6-dinitro-4-octylphenyl crotonate, 2,4-dinitro-6-octylphenol and 2,6-dinitro-4-octylphenol, in crops was examined. The four compounds were extracted with acetone and re-extracted into hexane. After clean-up successively by hexane-acetonitrile partition and silica gel column chromatography, the compounds were determined by HPLC with an UV detector (245 nm). The column was Cosmosil 5C18 (ODS, 5 micron) and the eluent was methanol-water-acetic acid (330:70:1). The limit of detection was 0.02 ppm and the recoveries from crops (spiked with 0.5 ppm) were 85-100%. The four compounds were determined simultaneously and the method was shown to be applicable to residue analysis of these compounds in crops sprayed with dinocap.

[A nationwide study of the antimicrobial susceptibility of clinical isolates of Escherichia coli in Japan]

We studied the antimicrobial susceptibility of E. coli isolated in 1983 and 1984 and also the yearly changes of the susceptibility of E. coli from 1980 to 1984 isolated in 103 hospitals in Japan. Antibiotics used for MIC determination were ampicillin (ABPC) as a penicillin, cefazolin (CEZ) as a cephalosporin, cefmetazole (CMZ) as a cephamycin and gentamicin (GM) as an aminoglycoside. Numbers of isolates tested were 2,321 strains in 1983 and 1,965 strains in 1984. CMZ was the most effective agent among the 4 antibiotics tested, followed by GM and CEZ in this order. A large number of the isolates were inhibited by 1.56 micrograms/ml on CMZ and GM and by 6.25 micrograms/ml of CEZ. About two-thirds of the isolates were inhibited at a concentration of 12.5 micrograms/ml or less of ABPC. The susceptibility of E. coli against the 4 antibiotics changed little year by year and the tendency of the appearance of resistant strains did not increase in the last 5 years.

[A nationwide study of the antimicrobial susceptibility of clinical isolates of Klebsiella sp. in Japan]

We have reported the antimicrobial susceptibility of clinical isolates of Escherichia coli in 1983 and 1984 to 4 antibiotics, ampicillin (ABPC), cefazolin (CEZ), cefmetazole (CMZ) and gentamicin (GM), in the previous report. In this paper, we described the antimicrobial susceptibility of Klebsiella sp. to the same antibiotics during the same period reported for E. coli before. Numbers of isolates tested were 1,671 strains in 1983 and 1,374 strains in 1984. We determined MICs of the 4 antibiotics against isolates by the standard method of the Japan Society of Chemotherapy. The most effective agent was GM among the 4 antibiotics. CMZ had a similar antimicrobial activity to GM. Resistance rates were low for both agents. CEZ had a fairly good antimicrobial activity, but it was less active than GM and CMZ. ABPC was not effective. There was neither significant annual change of antimicrobial activity of each agent against isolates nor an increasing tendency of resistant strains in the last 5 years. Depending on isolates from clinical materials, differences in the susceptibility were noted and there was a high ratio of resistant organisms among isolates from urine.