Investigation into the usefulness of cynomolgus monkeys with spontaneously elevated intraocular pressure as a model for glaucoma treatment research

Many glaucoma treatments focus on lowering intraocular pressure (IOP), with novel drugs continuing to be developed. One widely used model involves raising IOP by applying a laser to the trabecular iris angle (TIA) of cynomolgus monkeys to damage the trabecular meshwork. This model, however, presents challenges such as varying IOP values, potential trabecular meshwork damage, and risk of animal distress. This study investigated whether animals with naturally high IOP (>25 mmHg) could be used to effectively evaluate IOP-lowering drugs, thereby possibly replacing laser-induced models. Relationships between TIA size, IOP, and pupil diameter were also examined. Three representative IOP-lowering drugs (latanoprost, timolol, ripasudil) were administered, followed by multiple IOP measurements and assessment of corneal thickness, TIA, and pupil diameter via anterior segment optical coherence tomography (AS-OCT). There was a positive correlation was noted between IOP and corneal thickness before instillation, and a negative correlation between IOP and TIA before instillation. Our findings suggest animals with naturally high IOP could be beneficial for glaucoma research and development as a viable replacement for the laser-induced model and that measuring TIA using AS-OCT along with IOP yields a more detailed evaluation.

Creation of Retinal Vein Occlusion Model in Cynomolgus Monkeys and Determination of its Pathological Features

OBJECTIVE

A retinal vein occlusion (RVO) is a relatively common retinal vascular disorder, especially in the elderly. Many experiments have been performed on patients with an RVO but performing any type of experiments and especially longitudinal experiments on humans is difficult, if not impossible, on ethical grounds. Therefore, we have created a retinal vein occlusion (RVO) model by laser irradiation of cynomolgus monkeys after intravenous injection of rose bengal. We evaluated the pathological changes of the retina, and the effects of ranibizumab, an anti-vascular endothelial growth factor (VEGF) antibody, on the characteristics of the RVO.

METHODS

The integrity of the vascular system was evaluated by fluorescein angiography (FA), and the retinal thickness and volume were determined by optical coherence tomography (OCT). The cytokines and growth factors in the aqueous humour were identified by multiplex profiling.

RESULTS

Our results showed that ranibizumab decreased the degree of vascular leakage and retinal edema at 1-3 days (acute phase) and 3-7 days (subacute phase), and suppressed foveal thinning at 28-42 days (chronic phase) after the laser irradiation. Ranibizumab also decreased the area of the foveal avascular zone, and the area was negatively and significantly correlated with the thickness of the ganglion cell layer (GCL) complex. Furthermore, ranibizumab reduced the increased expression of VEGF in the aqueous humor, but did not affect the expressions of interleukin-6 (IL-6), monocyte chemotactic protein-1 (MCP-1), angiopoietin-1 (ANG-1), or angiopoietin-2 (ANG-2). These findings suggest that ranibizumab attenuates the retinal edema and subsequent retinal atrophy in part by neutralizing VEGF. However, other cytokines and growth factors were also affected by the ranibizumab, which suggests that not only VEGF but also other unidentified agents might play a role in the pathogenesis of the RVO.

CONCLUSION

We have created a non-human primate RVO model, which resembles the clinical RVO pathology. In this model, an injection of ranibizumab leads to a reduction in vascular leakage and the retinal thickness and volume by blocking the expression of VEGF. Our model might be useful for investigating the pathological mechanisms of RVOs and explore new therapeutic agents for RVO.

Anti-vascular Endothelial Growth Factor Antibody Limits the Vascular Leakage and Decreases Subretinal Fibrosis in a Cynomolgus Monkey Choroidal Neovascularization Model

OBJECTIVE

This study was conducted to evaluate the effects of anti-vascular endothelial growth factor (VEGF) antibody (bevacizumab) on vascular leakage and fibrosis in a monkey choroidal neovascularization (CNV) model. The relationship between fibrotic tissue and subretinal hyper-reflective material (SHRM), in optical coherence tomography (OCT) images, was also investigated.

METHODS

Experimental CNV was induced in male cynomolgus monkeys by laser photocoagulation. Intravitreal injection of bevacizumab at 0.5 mg/eye/dosing was initiated 2 weeks before or after laser irradiation and thereafter, conducted intermittently at 2- or 3-week intervals. Fluorescein fundus angiography (FA) and OCT imaging were conducted weekly from 2 to 7 weeks after laser irradiation. CNV leakage was evaluated by an established grading method using FA images. To assess the fibrosis and scarring, Masson's trichrome specimens of each CNV lesion were prepared, and morphometric analysis was conducted using an image analysis software.

RESULTS

The effects of bevacizumab on vascular leakage were shown using an established evaluation method. Morphometric analysis of Masson's trichrome-stained (MT) specimens revealed that collagen fiber synthesis was suppressed by bevacizumab pre-treatment (-29.2%) or post-treatment (-19.2%). SHRM was detected in OCT images in a monkey CNV model, and a significant correlation between the SHRM area in the OCT images and the collagen fiber area in the MT specimens was noted.

CONCLUSION

In the established cynomolgus monkey CNV model, bevacizumab prevented blood leakage but could not completely suppress fibrosis. SHRM in the OCT images reflected retinal fibrous tissue in a laser-induced CNV monkey model. This model might be useful for elucidating the pathology and development therapy for neovascularization or fibrosis.

Biomechanical behaviour of a French femoral component with thin cement mantle: The 'French paradox' may not be a paradox after all

Objective

Cement thickness of at least 2 mm is generally associated with more favorable results for the femoral component in cemented hip arthroplasty. However, French-designed stems have shown favorable outcomes even with thin cement mantle. The biomechanical behaviors of a French stem, Charnley-Marcel-Kerboull (CMK) and cement were researched in this study.

Methods

Six polished CMK stems were implanted into a composite femur, and one million times dynamic loading tests were performed. Stem subsidence and the compressive force at the bone-cement interface were measured. Tantalum ball (ball) migration in the cement was analyzed by micro CT

Results

The cement thickness of 95 % of the proximal and middle region was less than 2.5 mm. A small amount of stem subsidence was observed even with collar contact. The greatest compressive force was observed at the proximal medial region and significant positive correlation was observed between stem subsidence and compressive force. 9 of 11 balls in the medial region moved to the horizontal direction more than that of the perpendicular direction. The amount of ball movement distance in the perpendicular direction was 59 to 83% of the stem subsidence, which was thought to be slip in the cement of the stem. No cement defect and no cement breakage were seen.

Conclusion

Thin cement in CMK stems produced effective hoop stress without excessive stem and cement subsidence. Polished CMK stem may work like force-closed fixation in short-term experiment.

Cite this article: Y. Numata, A. Kaneuji, L. Kerboull, E. Takahashi, T. Ichiseki, K. Fukui, J. Tsujioka, N. Kawahara. Biomechanical behaviour of a French femoral component with thin cement mantle: The ‘French paradox’ may not be a paradox after all. Bone Joint Res 2018;7:485–493. DOI: 10.1302/2046-3758.77.BJR-2017-0288.R2.

The Effect of Total Meniscectomy versus Caudal Pole Hemimeniscectomy on the Stifle Joint of the Sheep

Total medial meniscectomy and caudal pole hemimeniscectomy were performed on the stifle joints of twelve sheep. The two forms of meniscectomy produced a comparable degree of postoperative lameness that resolved within two weeks of the operations. After six months the sheep were euthanatised and the stifle joints examined. Fibrous tissue that replaced the excised meniscus in the total meniscectomy group did not cover as much of the medial tibial condyle as the residual cranial pole and caudal fibrous tissue observed following hemimeniscectomy. The articular cartilage from different regions within the joints was examined for gross and histological evidence of degeneration. Analyses of the articular cartilage for water content, glycosaminoglycan composition and DNA content were performed. The proteoglycan synthesis and release from explanted articular cartilage samples in tissue culture were also measured. There were significant pathological changes in the medial compartment of all meniscectomised joints. The degree of articular cartilage degeneration that was observed following total meniscectomy and caudal pole meniscectomy was similar. Caudal pole hemimeniscectomy, involving transection of the meniscus, causes the same degree of degeneration of the stifle joint that occurs following total meniscectomy.

The effect of total medial meniscectomy versus caudal pole hemimeniscectomy on the stifle joint of sheep was studied experimentally. Six months after the operations gross pathology, histopathology, cartilage biochemical analysis and the rate of proteoglycan synthesis in tissue culture were used to compare the articular cartilage harvested from the meniscectomised joints. Degeneration of the articular cartilage from the medial compartment of the joints was present in both of the groups. Caudal pole hemimeniscectomy induces a comparable degree of articular cartilage degeneration to total medial meniscectomy in the sheep stifle joint.

The influence of cement thickness on stem subsidence and cement creep in a collarless polished tapered stem: When are thick cement mantles detrimental?

Objectives

Favourable results for collarless polished tapered stems have been reported, and cement creep due to taper slip may be a contributing factor. However, the ideal cement thickness around polished stems remains unknown. We investigated the influence of cement thickness on stem subsidence and cement creep.

Methods

We cemented six collarless polished tapered (CPT) stems (two stems each of small, medium and large sizes) into composite femurs that had been reamed with a large CPT rasp to achieve various thicknesses of the cement mantle. Two or three tantalum balls were implanted in the proximal cement in each femur. A cyclic loading test was then performed for each stem. The migration of the balls was measured three-dimensionally, using a micro-computed tomography (CT) scanner, before and after loading. A digital displacement gauge was positioned at the stem shoulder, and stem subsidence was measured continuously by the gauge. Final stem subsidence was measured at the balls at the end of each stem.

Results

A strong positive correlation was observed between mean cement thickness and stem subsidence in the CT slices on the balls. In the small stems, the balls moved downward to almost the same extent as the stem. There was a significant negative correlation between cement thickness and the horizontal:downward ratio of ball movement.

Conclusion

Collarless polished tapered stems with thicker cement mantles resulted in greater subsidence of both stem and cement. This suggests that excessive thickness of the cement mantle may interfere with effective radial cement creep.

Cite this article: E. Takahashi, A. Kaneuji, R. Tsuda, Y. Numata, T. Ichiseki, K. Fukui, N. Kawahara. The influence of cement thickness on stem subsidence and cement creep in a collarless polished tapered stem: When are thick cement mantles detrimental? Bone Joint Res 2017;6:–357. DOI: 10.1302/2046-3758.65.BJR-2017-0028.R1.

Cytotoxicity of a novel indoloquinone eo9 in hypoxic non-small-cell lung-cancer cell-lines

3-Hydroxymethyl-5-aziridinyl-1-methyl-[1H-indole-4,7-dione]-prop-beta-en -alpha-ol (EO9) is a bioreductive anticancer agent active for non-small cell lung cancer (NSCLC) and structurally related to mitomycin C (MMC). DT-diaphorase (DTD) is regarded as a two electron reductase that plays an important role in the biotransformation of MMC to antitumor metabolites. To evaluate the role of DTD as a bioactivator of EO9 in NSCLC cell lines under oxic and hypoxic conditions, we examined the inhibitory effect of dicumarol which was regarded as a selective inhibitor of DTD on the sensitivity to EO9 in vitro. In this study, we used an MMC-resistant NSCLC cell line (PC-9/MC4) which was established from a PC-9 cell line as a parent cell line by continuous exposure to MMC in our laboratory. We reported previously that the subline PC-9/MC4 was 6.7-fold more resistant to MMC than PC-9 with decreased DTD activity. The IC50 value of PC-9 against EO9 was significantly increased by co-incubation with dicumarol under oxic conditions. EO9 was more cytotoxic against PC-9/MC4 than against PC-9 cells and the enhancement was impaired by tempol under hypoxic conditions. These findings suggest a suppressive role of DTD against one-electron reduction pathway in the bioactivation of EO9 under hypoxic conditions and EO9 may be more active against oxygen-deficient solid tumors especially in MMC-resistant NSCLC cells with low levels of DTD activity.

180 EFFECT OF Dnmt1p mRNA KNOCK DOWN ON Dnmt1 PROTEIN TRANSLATION IN MOUSE TESTIS

We have reported that there was a significant reduction (P < 0.05) in the relative amount of Dnmt1p mRNA in spermatozoa from aged male mice (Kato et al. 2007 Reprod. Fertil. Dev. 19, 277 abst.). The reduction of mRNA levels of Dnmt1p in spermatozoa would lead to altered epigenetic modification of the genome. Dnmt1p is one of 5′ exon alternative isoforms of Dnmt1 and its mRNA is specifically expressed in the pachytene spermatocyte. However, the function of Dnmt1p still has not been elucidated. In this study, we tried to elucidate the function of Dnmt1p in the male mouse reproductive system. This was accomplished by suppressing the expression level of Dnmt1p in the whole testis by short hairpin RNA (shRNA) expression, which was specifically designed from mouse Dnmt1p mRNA. Dnmt1p cDNA was cloned from total RNA extracted from a piece of testis from a C57BL/6J male mouse. Four shRNA expression vectors were constructed and the knock-down efficiency of each shRNA expression vector was evaluated by flow cytometry. From these results, the 589 shRNA expression vector was picked out for further experimentation. The 589 shRNA expression vector was linearized and injected into the pronuclei of C57BL/6J mouse embryos. After injection, the embryos were cultured for 24 h and cleavage was evaluated. Cleaved embryos were transferred into oviducts of recipient ICR mice. After 18 to 19 days, fetuses were delivered by C-section. Two weeks after the birth, the existence of the 589 shRNA expression gene construct in its genome was evaluated by PCR. From founders with 589 shRNA expression gene construct in its genome, finally 1 TG strain was established and used for further experimentation. Two F2 -generation male mice with the 589 shRNA expression gene construct, 2 F2-generation male mice without the 589 shRNA expression gene construct and 1 C57BL/6J wild-type male mouse were used for evaluating the expression level of Dnmt1p mRNA in the whole testis by quantitative PCR. Then, thin sections of testis derived from the F2-generation mouse, which showed a suppressed expression level of Dnmt1p, was evaluated by immunostaining for Dnmt1 protein. The survival rate of mouse embryos after gene injection was 76.8% (202/263) and the cleavage rate of gene-injected embryos was 69.8% (141/202). The developmental rate of transferred embryos to the birth was 19% (27/139). The rate of newborn mice with the 589 shRNA expression gene construct was 37% (10/27). The fertility of established TG strain mouse was normal and there was no abnormality in the thin section figure of testis stained with hematoxylin-eosin double staining method. The relative expression level of Dnmt1p mRNA in the whole testis of the F2 TG mouse was ∼25% of C57BL/6J wild-type male mouse (P < 0.05, Student's t-test). There was Dnmt1 protein in seminiferous tubules, especially in spermatids of C57BL/6J wild-type male mouse. However, there was no Dnmt1 protein in seminiferous tubules of the F2 TG mouse. From these results, it was concluded that the expression of Dnmt1p mRNA was associated in some way with the translation of the Dnmt1 protein in the mouse testis.

Isolation and Characterization of a Bacillus cereus Mutant Strain Hyperproductive of Exo-beta-Amylase

Starting with a strain of Bacillus cereus excreting about 40-fold more beta-amylase than does the original wild-type strain, we isolated, after mutagenesis with N-methyl-N'-nitro-N-nitrosoguanidine, a strain designated BQ10-S1 SpoIII which showed under optimal conditions a further 5.5-fold increase in beta-amylase activity. The amylase production of this strain was observed to increase in the presence of 0.5% glucose or 1% maltose and, more markedly, in the presence of 2% soluble starch in the culture medium. The enzyme produced by this strain was immunologically identical to the wild-type enzyme, suggesting that either the copy number of the gene or the efficiency of enzyme synthesis from it, or both, are altered in this strain.

In patients with ulcerative colitis, adsorptive depletion of granulocytes and monocytes impacts mucosal level of neutrophils and clinically is most effective in steroid naïve patients

BACKGROUND

The aetiology of ulcerative colitis is inadequately understood, and drug therapy has been empirical rather than based on sound understanding of disease aetiology. This has been a major factor for refractoriness and adverse drug effects as additional complications. However, ulcerative colitis by its very nature is exacerbated and perpetuated by inflammatory cytokines, which are released by peripheral granulocytes and monocytes as well. Additionally, active ulcerative colitis is often associated with elevated peripheral granulocytes and monocytes with activation behaviour and are found in vast numbers within the colonic mucosa. Hence, from the clinicopathologic viewpoint, granulocytes and monocytes are appropriate targets for therapy in ulcerative colitis. Based on this thinking, an Adacolumn has been developed for depleting excess granulocytes and monocytes by adsorption.

METHODS

By colonoscopy, biopsy and histology, we investigated the impact of granulocyte and monocyte adsorption (GMA) on the mucosal level of granulocytes and monocytes in patients with active ulcerative colitis. Forty-five patients (26 steroid naïve and 19 steroid-dependent), mean age 44.7 yr, were included. Twenty patients had total colitis and 25 had left-sided colitis. Each patient was given up to 11 GMA sessions over 12 weeks. No patient received additional medications within 4 weeks (steroid) to 8 weeks (other immunosuppressants) prior to entry or during the GMA course. Colonoscopy together with biopsy was done at entry and within 2 weeks after the last GMA session.

RESULTS

At entry, the mean clinical activity index was 12.6; range 10-16. A total of 400 colonic biopsies were examined, which revealed massive infiltration of the colonic mucosa by granulocytes, and GMA was associated with striking reduction of granulocytes in the mucosa. At week 12, 33 of 45 patients (73.3%, P<0.01) had achieved clinical remission (the mean clinical activity index <or= 4). Colonoscopy revealed that most non-responders had deep colonic ulcers and extensive loss of the mucosal tissue. The response rate in steroid naïve subgroup was 22 of 26 patients (84.6%, P<0.005) and in steroid-dependent was 11 of 19 (57.9%, P<0.05 and P=0.02154 for steroid naïve vs. steroid-dependent). Patients who achieved remission could continue with their salicylates. On average, remission was sustained for 7.8 months in all 33 responders.

CONCLUSIONS

This is the first report showing a striking difference in clinical response to GMA between steroid naïve and steroid-dependent patients. Further, patients with deep colonic ulcers together with extensive loss of the mucosal tissue are not like to respond to GMA.

Risk factors for clustering of tuberculosis cases: a systematic review of population-based molecular epidemiology studies

BACKGROUND

Many molecular epidemiology studies have been conducted to identify risk factors for clustering of tuberculosis (TB) cases in the population.

OBJECTIVE

To estimate the impact of commonly investigated risk factors on TB clustering.

METHODS

Ten electronic databases were searched up to January 2006 along with a hand search of the International Journal of Tuberculosis and Lung Disease and bibliographies of review articles. Meta-analyses of odds ratios (ORs) for various risk factors were conducted using random effect models, stratified by TB incidence. Meta-regressions were employed to account for the heterogeneity in clustering proportions and the magnitudes of risk.

FINDINGS

The TB clustering proportion varied greatly (7.0-72.3%) among 36 studies in 17 countries. In multiple meta-regression analyses, high TB incidence, mean cluster size and conventional contact tracing were significantly associated with higher clustering. The pooled ORs (95%CIs) for low and high/intermediate TB incidence studies, using a cut off of 25/100000 per year, were 3.4 (2.7- 4.2) and 1.6 (1.3-2.1) for local-born status, 1.6 (1.5-1.7) and 1.7 (1.3-2.2) for pulmonary TB and 1.2 (1.1-1.3) and 1.3 (1.1-1.7) for smear-positive cases, respectively. Male sex, local birth, alcohol abuse and injection drug use were significantly higher risks in low TB incidence studies than in the high/intermediate ones.

INTERPRETATION

Meta-analyses yielded significant estimates of ORs for several risk factors across both levels of TB incidence. Alcohol abuse, injection drug use and homelessness--all characteristics of marginalized populations--were found to be consistently significant in populations of low TB incidence. More research is needed to better understand TB transmission dynamics in high-burden countries.

Epithelial and stromal genetic instability contributes to genesis of colorectal adenomas

BACKGROUND

Previously, we indicated that stromal genetic instability might contribute to tumorigenesis of both sporadic and ulcerative colitis associated colorectal adenocarcinomas. Considering the established adenoma-adenocarcinoma sequence, in this study we analysed genetic instability in colorectal adenoma cells and surrounding stroma.

METHODS

In 164 colorectal tumours (34 hyperplastic polyps, 38 tubular adenomas with low grade dysplasia (TA-L), 51 tubular adenomas with high grade dysplasia (TA-H), and 41 invasive carcinomas), epithelial and stromal genetic instability with National Cancer Institute standard microsatellite markers and chromosome 17 (Chr17) markers, were analysed by a combination of laser capture microdissection and GeneScan approaches.

RESULTS

While frequencies of both loss of heterozygosity (LOH) and microsatellite instability (MSI) were extremely low in hyperplastic polyps, LOH in tubular adenomas was detected in both epithelial (TA-L 13.2%, TA-H 27.5%) and stromal (5.3% and 5.9%, respectively) elements, along with MSI (5.3% and 13.7%, and 5.3 and 5.9%, respectively). Frequencies of epithelial alterations were higher in TA-H than in TA-L, and greatest in the carcinoma group. On the other hand, frequencies of stromal LOH or MSI were almost constant (5.3% approximately 17.1%, 5.3% approximately 17.1%, respectively) in adenomas and invasive carcinomas. In addition, p53 was found to be significantly overexpressed in a greater proportion of TA-L with LOH than in those without genetic instability.

CONCLUSION

The results indicate the presence of genetic alterations in stroma from an early stage of carcinogenesis, accompanied by stepwise increasing genetic instability of epithelia with progression to cancer. Thus microenvironmental changes due to genetic alteration in Chr17 markers in stromal cells may play an important role in colon adenoma and adenocarcinoma development.

Chronic inflammatory demyelinating polyneuropathy: decreased claudin-5 and relocated ZO-1

OBJECTIVES

To clarify the dynamics of molecules composing the blood-nerve barrier (BNB) in inflammatory neuropathies.

METHODS

The expression of four tight junction (TJ) proteins-claudin-1, claudin-5, occludin, and ZO-1-was analysed immunohistochemically in sural nerve biopsy specimens obtained from patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP).

RESULTS

Claudin-1 was detected only in perineurial cells, whereas claudin-5 was present in endothelial cells, irrespective of vessel location or size. Occludin and ZO-1 were found in perineurial cells, in addition to some epineurial and endoneurial endothelial cells. In CIDP, percentages of endoneurial small vessels immunoreactive for claudin-5 were significantly decreased, as were ZO-1 immunoreactive endoneurial small vessels, with staining localised to interfaces between cells. Claudin-1 and occludin immunoreactivity did not differ appreciably between the neuropathies examined.

CONCLUSIONS

The downregulation of claudin-5 and altered localisation of ZO-1 seen in CIDP specimens may indicate that BNB derangement occurs in inflammatory neuropathies. Further investigation of TJ molecules may suggest new treatments based on properties of the BNB.

Possible alternative carcinogenesis pathway featuring microsatellite instability in colorectal cancer stroma

Differential microsatellite instability (MSI) in tumour epithelial and stromal compartments has not been well examined for colorectal cancers. Using laser-captured microdissection, separate specimens of these compartments of 40 sporadic colorectal cancers were sampled and MSI was tested with four markers. To examine the relation between the MSI phenotype in the stroma and other genetic events and histopathological features, p53 and K-ras gene mutations were analysed, and the expression of p53, hMLH1, and hMSH2 protein was determined by immunohistochemistry. Microsatellite instability positive results were obtained for both epithelium (34%) and stromal tissue (41%). While MSI in epithelium correlated with differentiation and Dukes' stage, that in stroma demonstrated an inverse relation, being particularly frequent in well-differentiated adenocarcinomas (54%) and Dukes' A lesions (55%). Further, a significant inverse correlation between p53 protein overexpression in the epithelium and MSI in the stroma was found (P=0.02475). The results suggest an alternative pathway of carcinogenesis involving stromal genetic instability in the development of colorectal cancers.

[Relationship between prothrombin time international normalized ratio and thrombo test (%)]

OBJECTIVES

The optimal therapeutic range for laboratory evaluation of oral anticoagulant therapy is now defined by the prothrombin time international normalized ratio (PT-INR). However, the thrombo test (TT), an alternative method to measure intensity of anticoagulation, is also currently used throughout Japan. The relationship between PT-INR and TT (%) has yet to be clarified. This study investigated the relationship between PT-INR and TT (%).

METHODS

The PT-INR and TT (%) were simultaneously measured of 505 consecutive samples from patients treated with warfarin in our hospital. Fourteen functions were used for regression analyses: a fractional function (Y = a/X + b), a square root function (Y = aX0.5 + b), a natural logarithmic function (Y = a.lnX + b), a power series function (Y = aXb), a quotient function (Y = abX), and polynomial functions [Y = anXn + an - 1Xn - 1 +......+ a1X1 + b, (1 < or = n < or = 9)]. The results were confirmed by the same methods in 383 samples and 296 samples from another two laboratories.

RESULTS

The power series function showed the most significant (p < 0.0001) and highest adjusted R2 (0.858) correlation, with a regression formula of TT (%) = e4.48 (PT-INR)-2.09 in our laboratory. Using the same analyses, the power series function also showed the most significant and highest adjusted R2 in samples from the other two laboratories.

CONCLUSIONS

This study showed that a power series function is the most appropriate for expressing the relationship between PT-INR and TT (%) among the 14 functions. The function between PT-INR and TT (%) is mainly derived from the relationship between TT (%) and TT (sec). Both internal validity and external validity confirmed the relationship between PT-INR and TT (%).

Phospholipid alterations in hepatocyte membranes and transporter protein changes in cholestatic rat model

Biliary components are transported by hepatic adenosine triphosphate-binding cassette (ABC) transporters that are located in canalicular membranes. Physiological transporter function is related to membrane fluidity, which is modulated by the phospholipid composition of the lipid bilayer. We hypothesized that cholestasis may alter transporter function by modifying phospholipid species to protect the cell from cholestatic damage. Therefore, we examined the expression of ABC transport proteins and their mRNA levels in canalicular membrane vesicles isolated from rat liver 6 hr or three days after bile duct ligation. Membrane lipid composition and membrane fluidity of both sinusoidal and canalicular membrane vesicles were also examined. By 6 hr after bile duct ligation, we found a clear increase of mdr2 and bsep mRNA. These changes were associated with an increase of mdr-Pgp and with a clear decrease of mrp2 protein, and small decrease of bsep protein. In addition, mdrlb mRNA showed a strong increase by three days after bile duct ligation. Canalicular membrane fluidity decreased in a marked time-dependent manner, whereas sinusoidal membranes showed biphasic changes: increased fluidity at 6 hr and a decrease at three days. These changes were closely related to the changes of membrane lipid constitution; the saturated/unsaturated fatty acid ratio increased for phosphatidylcholine in canalicular membrane and the reverse occurred in sinusoidal membrane, and those for sphingomyelin showed the opposite pattern. We conclude that cholestasis causes modulation of ABC transporters as well as that of the lipid constitution in lipid bilayer. These may confer cytoprotective resistance to hepatocytes against cholestatic stress.

Dose-dependent conjugation of sulfobromophthalein and hepatic transit time in bile fistula rats: role of the microtubule-dependent vesicle pathway

Sulfobromophthalein (BSP) is selectively taken up by the liver and secreted into the bile as unconjugated and conjugated forms. Our previous study demonstrated that unconjugated BSP, but not conjugated BSP, caused the dissociation of biliary lipid secretion from that of bile acids, suggesting that the hepatic BSP conjugation rate partly regulated biliary lipid secretion. To evaluate the mechanisms through which biliary lipid secretion is regulated by exogenous organic anions, we intravenously administered BSP to male Sprague-Dawley rats at various doses either continuously or as a bolus. Then the relationship of the dose of BSP to its conjugation rate, hepatic transit time, and biliary lipid secretion was determined. BSP decreased biliary secretion of cholesterol and phospholipids in a dose-dependent manner without affecting bile acid secretion. In contrast, the proportion of conjugated BSP in bile was associated with the dose. Although the serum clearance of BSP after bolus infusion was constant regardless of the dose administered (50 or 200 nmol/100 g), BSP secretion was delayed with increasing doses: unconjugated BSP was secreted predominantly in the early phase (0-15 min after bolus injection), and conjugated BSP was the predominant form in the late phase (15-30 min). Pretreatment with colchicine reduced the conjugation rate and hepatic transit time of BSP, suggesting that the microtubule-dependent vesicle pathway plays a role in biliary excretion and conjugation of BSP. We conclude that biliary lipid secretion is influenced by organic anions with an affinity for bile acids such as BSP and that this effect is dependent upon the hepatic metabolic rate, i.e., conjugation rate. The hepatic transit time also plays a key role in this process by influencing metabolism.

Involvement of agouti-related protein, an endogenous antagonist of hypothalamic melanocortin receptor, in leptin action

To understand the role of agouti-related protein (AGRP), an endogenous antagonist of hypothalamic melanocortin receptor, in leptin action, we produced a full-length recombinant AGRP and examined its effect on the satiety effect of leptin. We also studied leptin's regulation of hypothalamic AGRP mRNA expression. A single intracerebroventricular (i.c.v.) injection of AGRP significantly increased cumulative food intake and body weight in a dose-dependent manner in rats. The leptin-induced inhibition of food intake and body weight was reversed by co-injection of AGRP in a dose-dependent manner. Hypothalamic AGRP mRNA expression was upregulated in leptin-deficient ob/ob mice and leptin receptor-deficient db/db mice and downregulated in lethal yellow agouti mice (KKAy mice) with hyperleptinemia. A single i.c.v. injection of leptin reversed the increased AGRP mRNA levels in ob/ob mice but not in db/db mice. In control mice and KKAy mice, AGRP mRNA expression was upregulated during fasting, when plasma leptin concentrations were decreased. No significant increase in AGRP mRNA expression was noted during fasting in control mice and KKAy mice treated with leptin. This study provides the first direct evidence that AGRP is a negative regulator of leptin action, and leptin downregulates hypothalamic AGRP production. Because leptin is shown to increase hypothalamic alpha-melanocyte stimulating hormone (alpha-MSH) production, our data suggest that its action via the hypothalamic melanocortin system is determined by the balance between the levels of its agonist and antagonist, alpha-MSH and AGRP.

Sympathetic activation of leptin via the ventromedial hypothalamus: leptin-induced increase in catecholamine secretion

Leptin is an adipocyte-derived blood-borne satiety factor that acts directly on the hypothalamus, thereby regulating food intake and energy expenditure. We have demonstrated that the hypothalamic arcuate nucleus (Arc) is a primary site of the satiety effect of leptin (Neurosci Lett 224:149-152, 1997). To explore the hypothalamic pathway of sympathetic activation of leptin, we examined the effects of a single intravenous or intracerebroventricular injection of recombinant human leptin on catecholamine secretion in rats. We also examined the effects of direct microinjection of leptin into the ventromedial hypothalamus (VMH), Arc, paraventricular nucleus (PVN), and dorsomedial hypothalamus (DMH) in rats. To further assess whether sympathetic activation of leptin is mediated via the VMH, we also examined the effects of a single intravenous injection of leptin in VMH-lesioned rats. A single injection of leptin (0.25-1.0 mg i.v./rat or 0.5-2.0 pg i.c.v./rat) increased plasma norepinephrine (NE) and epinephrine (EPI) concentrations in a dose-dependent manner. Plasma NE and EPI concentrations were increased significantly when leptin was injected directly into the VMH but were unchanged when injected into the Arc, PVN, and DMH. Plasma NE and EPI concentrations were unchanged in VMH-lesioned rats that received a single intravenous injection of leptin. The present study provides evidence that a leptin-induced increase in catecholamine secretion is mediated primarily via the VMH and suggests the presence of distinct hypothalamic pathways mediating the satiety effect and sympathetic activation of leptin.

Eicosapentaenoic acid release from the red alga Pachymeniopsis lanceolata by enzymatic degradation

Forty-eight species of seaweeds from Japanese waters were screened for the valuable polyunsaturated fatty acids eicosapentaenoic acid (EPA). The eight species that contained the highest levels of these compounds were analyzed in detail. Of all species tested the red alga Pachymeniopsis lanceolata contained the highest EPA concentration, and it was present as both the free and bound forms. EPA constituted 38.7% of total fatty acids, and polar lipids were the main constituent of the total lipids in P. lanceolata. EPA was obtained from the marine algae P. lanceolata by enzymatic hydrolysis of the total lipids extract using phospholipase A2 (PLA2). The release of EPA reached a plateau after 10 min of enzymatic treatment. These results suggest that P. lanceolata is a useful natural source of EPA and that PLA2 treatment is a convenient method for obtaining EPA from the red alga.

Effect of trazodone in a single dose before bedtime for sleep disorders accompanied by a depressive state: dose-finding study with no concomitant use of hypnotic agent

This was the first dose-finding study of trazodone that was designed to be free of the concomitant use of hypnotics, in which the drug was administered in a single dose for sleep disorders combined with a depressive state. As a result, trazodone at the dosage of 50-100 mg/day improved sleep disorders, particularly at the 100 mg/day dosage. It was confirmed that trazodone improved sleep disorders combined with a depressive state when it was administered in a single dose before bedtime with no concomitant hypnotics.

Structure-function studies of human leptin

To elucidate the structural requirement of human leptin for its functions, the wild-type, mutant-type, C-terminal deletion, and N-terminal deletion were expressed in Escherichia coli and purified in soluble forms. These leptin analogs were intracerebroventrically injected into C57BL/6J ob/ob mice, and their in vivo biological activities were evaluated. The mutant-type leptin lacking a C-terminal disulfide bond reduced food intake at doses of more than 15 pmol/mouse, which was as effective as the wild-type leptin. C-terminal deletion without the loop structure, also significantly, but to a lesser extent, reduced food intake at doses of more than 90 pmol/mouse. However, N-terminal deletions showed no effect on food intake. We also evaluated the effects of the leptin analogs on radiolabeled leptin binding to its receptor in the choroid plexus using autoradiography. An excess of unlabeled mutant-type leptin as well as wild-type leptin led to complete inhibition of binding. C-terminal deletions led to weak inhibitory activity, whereas N-terminal deletions caused no inhibitory activity. These results clearly demonstrate that the N-terminal region of leptin is essential for both its biological and receptor binding activities. The amino acid sequence of the C-terminal loop structure is also important for enhancing these actions, whereas the C-terminal disulfide bond is not needed.

Stabilities of N-acetyl-beta-D-glucosaminidase (NAG) isoenzymes in urine: advantage of NAG isoenzyme B measurement in clinical applications

N-Acetyl-beta-D-glucosaminidase (NAG) is a widely used urinary enzyme for the assessment of renal diseases. We studied the stabilities of NAG isoenzymes in urine at 37 degrees C by enzyme assay and ELISA using a model simulating in vivo conditions. The stabilities were found to be affected by the pH. Under mild acidic condition (about pH 6), there was no significant loss of enzymatic activity of NAG isoenzyme A, enzymatic activity of NAG isoenzyme B and immunological activity of NAG isoenzyme B even after 8 h incubation. In contrast, under alkaline condition (about pH 8), the enzymatic activity of NAG isoenzyme A was rapidly lost, whereas both enzymatic and immunological activities of NAG isoenzyme B were maintained at more than 80% of their initial values. Also, we found that the ratios of endogenous NAG isoenzyme B to total NAG were elevated in alkaline urine samples. These results indicate that NAG isoenzyme A, which is a major isoenzyme in normal urine (pH 5-7), seems to be inactivated in alkaline urine. Our results suggest that for alkaline urine, NAG isoenzyme B should be measured to avoid misinterpretation of total NAG enzymatic activities.

Comparison of thrombolytic therapies with mutant tPA (lanoteplase/SUN9216) and recombinant tPA (alteplase) for acute myocardial infarction

The fibrinolytic capacity of patients with acute myocardial infarction (AMI) is known to be impaired. The primary regulatory element of the fibrinolytic system is plasminogen activator inhibitor (PAI). It has been previously observed that there are 2 peaks in the plasma PAI level of AMI patients at 4h and 16h after thrombolytic therapy with recombinant tissue plasminogen activator (rtPA). Lanoteplase/SUN9216 is a mutant tPA with a biological half-life longer than that of rtPA. Thrombolytic therapy with mutant tPA or rtPA was carried out consecutively in 21 patients with AMI (8 patients as the mutant tPA group, and 13 patients as the rtPA group). The recanalization time of the mutant tPA group was significantly faster than that of the rtPA group (16.1 +/- 3.9 min vs 39.6 +/- 4.8 min, p<0.01). The PAI activity at 4h after the initiation of thrombolysis was significantly lower in the mutant tPA group than in the rtPA group (8.74 +/- 5.46IU/L vs 26.74 +/- 3.35 IU/L, p<0.01). There was a one mild peak in serial plasma PAI activity levels 24h after the initiation of thrombolysis. The results suggest that thrombolytic therapy with mutant tPA reduced the impairment of fibrinolytic capacity. The mutant tPA gives faster recanalization and lower PAI activity after successful thrombolysis, compared with rtPA.

Development of a sensitive ELISA for human leptin, using monoclonal antibodies

A new, sensitive ELISA for human leptin in plasma and cerebrospinal fluid (CSF) was developed, using monoclonal antibodies. The lower limit of detection of this ELISA was 0.78 pg/assay. Both intra- and interassay imprecision values were <7%. The dilution curves of plasma and CSF showed good linearity, and the recovery was 83.2-95.6%. There was good correlation between plasma leptin concentrations by the ELISA and a commercially available RIA (r = 0.99). Our ELISA is advantageous because it does not require radioisotopes, it produces results in hours rather than days, and more importantly, it improves on the detection limit and plasma interference of the RIA kit. The new ELISA enables measurement of low concentrations of leptin, as are seen in CSF and in plasma of patients with anorexia nervosa.

Satiety effect and sympathetic activation of leptin are mediated by hypothalamic melanocortin system

Leptin is an adipocyte-derived blood-borne satiety factor that decreases food intake and increases energy expenditure, thereby leading to a substantial decrease in body weight. To explore the possible roles of the hypothalamic melanocortin system in leptin action, we examined the effects of intracerebroventricular (i.c.v.) injection of leptin with or without SHU9119, a potent antagonist of alpha-melanocyte stimulating hormone, on food intake, body weight, and mitochondrial uncoupling protein-1 (UCP-1) mRNA expression in the brown adipose tissue (BAT) in rats. A single i.c.v. injection of leptin decreased cumulative food intake and body weight gain, and increased UCP-1 mRNA expression during 3 h at the onset of the dark phase. Inhibition of food intake and body weight change with leptin was reversed by co-injection of SHU9119 in a dose-dependent manner. Co-injection of SHU9119 also inhibited completely the leptin-induced increase in UCP-1 mRNA expression in the BAT. Treatment with SHU9119 alone did not affect food intake, body weight, and UCP-1 mRNA expression in rats. The present study provides evidence that the hypothalamic melanocortin system plays a central role in both satiety effect and sympathetic activation of leptin.

Parathyroid hormone-related protein-induced hypercalcemia in SCID mice engrafted with adult T-cell leukemia cells

Parathyroid hormone-related protein (PTHrP) is considered to be one of the main causes of hypercalcemia associated with adult T-cell leukemia (ATL). To clarify the role of PTHrP and bone remodeling in the development of hypercalcemia in ATL, we examined the SCID mouse model of ATL that has previously been shown to mimic the disease in humans. Using this model, we found clear elevations in serum levels of calcium and C-terminal PTHrP (C-PTHrP). PTHrP mRNA was highly expressed in ATL cells proliferating in vivo. After the development of hypercalcemia, ATL mice were killed and bone histomorphometric analysis was performed. Bone volume was clearly decreased in the ATL mice. In comparison to control SCID mice, bone formation indices were very low in the ATL mice. Surprisingly, no significant difference was detected between the ATL mice and the control SCID mice in eroded surface/bone surface (ES/BS), a parameter of bone resorption. To our knowledge, the model presented here is the first animal model of ATL with humoral hypercalcemia. This is in contrast to previously reported, well-characterized animal models of human solid tumors associated with humoral hypercalcemia of malignancy (HHM). Furthermore, this model not only provides us with the opportunity to study the mechanisms underlying development of elevated calcium levels in ATL, but also allows us to test new therapeutic agents designed to treat hypercalcemia.

A psychobehavioral factor, alexithymia, is related to coronary spasm

The aim of this study was to assess whether the psychobehavioral pattern alexithymia is related to coronary artery spasm. Alexithymia, deficient psychological awareness, was examined using the Minnesota Multiphasic Personality Inventory Alexithymia Scale in 100 patients with angina pectoris in whom coronary spasm, defined as > or = 99% coronary narrowing, was documented upon ergonovine provocation, and in 109 patients with chest pain syndrome who were shown to have almost normal coronaries without inducible coronary spasm on coronary angiogram (control group). Alexithymia was approximately twice as prevalent in the coronary spasm group (31%) as in the control group (14%) (p<0.01). Among various conventional risk factors including hyperlipidemia, obesity, diabetes mellitus, hypertension, hyperuricemia, or family history of ischemic heart disease, only male sex and smoking were more prevalent in the coronary spasm group than in the control group (p<0.001). The odds ratios of coronary spasm adjusted for all the other risk parameters including sex and age were 4.14 [95% confidence interval (CI) 1.81-9.47] for alexithymia and 2.38 (95, CI 1.18-4.82) for smoking. A psychobehavioral pattern, alexithymia, relates to coronary spasm. This relationship is independent of the conventional coronary risk factors.

Immunoradiometric assay for the N-terminal fragment of proatrial natriuretic peptide in human plasma

Recently, the N-terminal fragment of proatrial natriuretic peptide (N-terminal proANP) has been proposed as a marker of chronic congestive heart failure. In this study, we established a two-step immunoradiometric assay using monoclonal antibodies and synthetic N-terminal proANP (1-67) as a standard. It allows us to measure plasma N-terminal proANP in only 4 h without prior extraction. The detection limit of this assay was 15 pmol/L for a 100 microL sample of plasma. Within-run CVs ranged from 1.7% to 2.9% and between-run CVs ranged from 4.2% to 5.1%. The dilution curves of plasma samples showed good linearity and analytical recovery was 89-104%. The mean (+/-SD) N-terminal proANP in plasma of 33 healthy subjects was 188 (+/-71) pmol/L and 1030 (+/-411) pmol/L in 25 patients with heart failure. Our immunoradiometric assay is rapid and precise enough for routine determination of N-terminal proANP in human plasma.

New sandwich ELISA for human urinary N-acetyl-beta-D-glucosaminidase isoenzyme B as a useful clinical test

We have developed a new ELISA for quantifying N-acetyl-beta-D-glucosaminidase (NAG) isoenzyme B in human urine after raising monoclonal antibodies against the isoenzyme from human placenta. Though the obtained antibodies reacted not only to isoenzyme B but also to A, we could detect isoenzyme B selectively by a two-step sandwich ELISA with a pair of selected antibodies at low pH in the first reaction. The detected limit was 0.5 microgram/L for a sample volume of 25 microL. Within-run CVs ranged from 2.5% to 5.4% and between-run CVs ranged from 6.2% to 9.1%. Recoveries of NAG isoenzyme B added to each of three urine samples ranged from 91% to 114%. The dilution curves of urine samples showed good linearity. The cross-reactivity of NAG isoenzyme A was practically negligible (2-3%). The mean value for NAG isoenzyme B in spot urines from healthy adults was 2.9 micrograms/g creatinine. This ELISA method is rapid and precise enough for routine determination of NAG isoenzyme B in human urine.

Identification of two closely related genes, inducible and noninducible carbonyl reductases in the rat ovary

Two closely related cDNAs encoding carbonyl reductase (CR) were isolated from the rat ovary and testis. One (inducible CR, iCR) was rapidly and strongly induced in the ovary by pregnant mare serum gonadotropin (PMSG), whereas the other (non-inducible CR, nCR) was constitutively expressed in the ovary and was not induced by PMSG. Both genes were also expressed in the rat testis. The cDNAs of rat iCR and nCR encode highly homologous proteins (86% identity in amino acid) with 277 and 276 amino acid residues, respectively. However, the 5'-upstream regions flanking respective genes are completely unrelated to each other except for a short (38 bp) overlap. These results indicate the presence of two closely related but differently regulated CR genes in rat gonadal tissues. Strong induction of iCR by PMSG suggests the importance of the gene in the ovarian follicular development.

Secretion of anterior pituitary hormones in patients with insulin-dependent diabetes mellitus and polyglandular autoimmune syndrome

We extracted gammaglobulins from the serum of 10 patients with insulin-dependent diabetes mellitus (IDDM) to investigate their effect on anterior pituitary hormone secretion using cultures of rat anterior pituitary cells. Three of the 10 patients also had the polyglandular autoimmune syndrome (PGA) type III with an isolated failure of anterior pituitary hormone secretion. The gammaglobulin from each of the 3 patients with PGA and an isolated failure of secretion of adrenocorticotropic hormone (ACTH), thyroid stimulating hormone (TSH) or gonadotropin inhibited the secretion of ACTH, TSH or gonadotropin in cultures of rat anterior pituitary cells. The gammaglobulins obtained from the other 7 patients with IDDM also showed an inhibitory or stimulatory effect on anterior pituitary hormone secretion in vitro. We postulate that some patients with IDDM, especially those with other endocrine autoimmune diseases, may have substances in their gammaglobulin fraction that can affect the secretion of anterior pituitary hormones.

Hypothalamic-pituitary-adrenal axis in WBN/Kob rats with non-insulin dependent diabetes mellitus

In an attempt to define the hypothalamic-pituitary-adrenal (HPA) axis in non-insulin dependent diabetic rats (WBN/Kob), we measured plasma corticotropin releasing factor (CRF), as well as arginine vasopressin (AVP), ACTH, and corticosterone (B), CRF concentrations in the median eminence (ME), the remainder of the hypothalamus (rHY) and the neurointermediate lobe of the pituitary (NIL). We also measured Iodine-125-labeled ovine CRF ([125I]oCRF) binding in the brain and peripheral tissues. Body and thymus weight in WBN/Kob rats were significantly lower than in control Wistar rats, but adrenal weight was higher in WBN/Kob rats. Plasma ACTH levels were significantly higher in WBN/Kob rats than in the control rats. However, plasma CRF, AVP and B levels in WBN/Kob rats were not different from those in the control rats. The CRF concentration was significantly decreased in the ME of the diabetic rats, compared with control rats, but CRF concentrations in the rHY and NIL were unchanged in the two groups. A significant reduction in [125I]oCRF binding in the anterior pituitary was demonstrated in WBN/Kob rats, but no significant difference between the diabetic and control rats in CRF binding was observed in the frontal cortex, spleen or adrenal gland. These findings suggest that the HPA axis is chronically stimulated in the non-insulin dependent diabetic rats.

Biotinylated hyaluronan: a versatile and highly sensitive probe capable of detecting nanogram levels of hyaluronan binding proteins (hyaladherins) on electroblots by a novel affinity detection procedure

Hyaluronan influences cellular proliferation and migration in developing, regenerating and remodelling tissues and in tissues undergoing malignant tumour-cell invasion. The widespread occurrence of hyaluronan-binding proteins indicates that the recognition of hyaluronan is important to tissue organisation and the control of cellular behaviour. A number of extracellular matrix and cellular proteins, which have been termed the hyaladherins, have specific affinities for hyaluronan. These include cartilage link-protein, hyaluronectin, neurocan, versican and aggrecan, which all bind to HA within the extracellular matrix. Cellular receptors for hyaluronan such as CD44 and RHAMM (receptor for hyaluronate-mediated motility) have also been identified. In the present study biotinylated hyaluronan (bHA) was prepared by reacting adipic dihydrazide with a 170 kDa hyaluronan sample using the bifunctional reagent 1-ethyl-3-[3-(dimethylamino) propyl] carbodiimide. The resultant free amine moeity of the hydrazido-hyaluronan was then reacted with biotin succinimidyl ester (sulfo-NHS-biotin) to prepare the bHA. After 4-20% gradient sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and electroblotting to nitrocellulose membranes, bHA and avidin alkaline phosphatase conjugate could be used in conjunction with nitroblue tetrazolium/5-bromo-4-chloro-3-indolyl phosphate substrates to specifically visualise with high sensitivity (> or = 2 ng), bovine nasal cartilage link-protein, aggrecan hyaluronan binding region, and human fibroblast hyaluronan receptors such as CD-44. Conventional Western blotting using specific monoclonal antibodies to these proteins was also used to confirm the identities of these proteins.

Modulation of sensitivity to mitomycin C and a dithiol analogue by tempol in non-small-cell lung cancer cell lines under hypoxia

We examined the mechanisms involved in the bioactivation of mitomycin C (MMC) and a newly developed MMC analogue: 7-N-(2-([2-(gamma-L-glutamylamino)ethyl]dithio)ethyl)mitomycin C, KW-2149, in non-small-cell lung cancer (NSCLC) cell lines under aerobic and hypoxic conditions. To investigate these mechanisms, we used MMC-resistant non-small-cell lung cancer cell lines (PC-9/MC4) that had been established in our laboratory from the parent PC-9 cell line by continuous exposure to MMC. We previously reported that the MMC-resistant cell line (PC-9/MC4) was poor in NAD(P)H dehydrogenase (quinone) activity and approximately 6-fold more resistant than the parent cells (PC-9) to MMC on 2-h exposure under aerobic conditions. In this study, the subline PC-9/MC4 was 6.7-fold more resistant to MMC than PC-9, the parent cell line, under aerobic conditions, and 5.2-fold more resistant under hypoxic conditions after 2-h exposure to MMC. However, on co-incubation with tempol, an inhibitor of the one-electron reduction pathway, the sensitivity of PC-9/MC4 to MMC was impaired under hypoxic conditions, but the impairment was not evident under aerobic conditions. KW-2149, the newly developed MMC analogue, was cytotoxic for both PC-9/MC4 and PC-9 cells, and the sensitivity of both cell lines to KW-2149 was not changed by exposure to hypoxic conditions or by coincubation with tempol. There were no significant differences in the intracellular uptake of MMC and the activities of cytosolic detoxification enzymes between the PC-9 and PC-9/MC4 cell lines. These results support the hypothesis that the one-electron reduction pathway plays a partial role in the bioactivation of MMC, but not of KW-2149, and that KW-2149 is excellent at circumventing resistance to MMC in NSCLC.

Angiotensin converting enzyme as a genetic risk factor for coronary artery spasm. Implication in the pathogenesis of myocardial infarction

It has been reported that individuals with the D allele of an insertion/deletion (I/D) polymorphism of the angiotensin converting enzyme (ACE) gene are at greater risk for myocardial infarction (MI), especially among subjects normally considered to be at low risk. However, little is known about the mechanism by which the ACE polymorphism affects the risk of MI. Coronary artery spasm (CAS) is considered to be one possible mechanism for developing MI. We therefore examined the ACE polymorphism relation to CAS to determine if this was the mechanism by which the DD genotype influences MI. We studied 150 angiographically assessed Japanese males, all more than 60 yr old. CASs were detected using intracoronary injection of ergonovine maleate. Subjects were divided into three groups: those with CAS (group 1), those without CAS, but with fixed organic stenosis (group 2); and those without CAS and no organic stenosis (group 3). DD subjects were significantly represented in group 1 when compared with groups 2 (P = 0.002) and 3 (P = 0.026). These results suggest that the DD genotype relates to the greater risk for MI in the patients with CAS.

Effect of the initial bolus volume of recombinant tissue-type plasminogen activator on coronary recanalization and infarct size in Japanese acute myocardial infarction patients. Kumamoto University Myocardial Infarction Study (KUMIS) Group

Coronary recanalization rate and infarct size were compared between 2 different methods of intravenously administering recombinant tissue-type plasminogen activator (rt-PA) 41.4 mg; 1) an initial bolus dose of 30% followed by infusion of the remainder over 60 min (30% group), and an initial bolus dose of 10% followed by infusion of the remainder over 60 min (10% group). Thirty min after beginning rt-PA infusion, the coronary recanalization rate was higher in the 30% group than in the 10% group (82.9% (34/41) vs 53.7% (22/41), p < 0.01). The peak creatine kinase and peak creatine kinase-MB levels were lower in the 30% group than in the 10% group. We conclude that a higher initial bolus dose of rt-PA gives a higher rate of recanalization of the infarct-related artery at the very early phase, and probably leads to a smaller infarct size.

[The relationship between the improvement of cardiac function and the myocardial uptake of I-123 metaiodobenzylguanidine in patients with dilated cardiomyopathy treated by beta-blocker]

Chronic beta-blocker therapy improves hemodynamics and cardiac function in patients with idiopathic dilated cardiomyopathy. However, the change in myocardial uptake of I-123 metaiodobenzylguanidine (123I-MIBG) before and after treatment has not been determined. Myocardial imaging with 123I-MIBG was performed before and 2 or 3 months after beta-blocker (bisoprolol) therapy in 11 patients with dilated cardiomyopathy. The following parameters were compared before and after the treatment: 1) New York Heart Association functional class, 2) X-ray cardiothoracic ratio, 3) heart rate and blood pressure, 4) echocardiographic data (left ventricular end-diastolic and end-systolic diameters, and left ventricular ejection fraction), 5) plasma concentrations of epinephrine, norepinephrine and human atrial natriuretic peptide (HANP), and 6) exercise tolerance time by treadmill. The heart-to-mediastinum ratio of 123I-MIBG activities obtained 3 hours after intravenous injection (late H/M) and washout rate improved significantly after beta-blocker therapy. Cardiothoracic ratio, heart rate, echocardiographic parameters, HANP and exercise tolerance also improved significantly. Late H/M had no significant relationship with any of the clinical parameters, but washout rate was significantly related to left ventricular ejection fraction. These findings suggest that washout rate may be useful to assess the effect of short-term beta-blocker therapy in dilated cardiomyopathy patients.

[A case of successful treatment of chronic sternal osteomyelitis and mediastinitis after ascending aorta and hemiarch reconstruction]

Mediastinitis is one of severe and fatal complications after cardiac surgery, especially in the presence of a prosthetic graft. A 70-year-old male, who was suffered from chronic sternal osteomyelitis and mediastinitis after ascending aorta and hemiarch reconstruction was reported. He developed high fever and leucocytosis on the 16th postoperative day. Wound culture was positive for Grampositive organisms. He was diagnosed as having sternal osteomyelitis and mediastinitis and treated by sternal bone debridement and irrigation with dilute povidone iodine solution with no effects. Total excision of the infected sternum, irrigation with non-diluted solution of povidone iodine and omental transfer were performed successfully. The literature regarding omental transfer for mediastinitis and infected prosthetic grafts was briefly reviewed.

Role of sodium pump systems to determine sensitivity to mitomycin C in non-small cell lung cancer cell lines

There are some active transport systems in the cell membrane, such as potassium pump, calcium pump, and proton pump. Although it has been reported that sodium/potassium and sodium/calcium pumps of cell membrane play roles in the intracellular accumulation of anticancer agents, the significance of the active transport channels in accumulation of mitomycin C (MMC), one of the most active agents for non-small cell lung cancer (NSCLC) has been unclear. In this study, we evaluated the role of the potassium pump, calcium pump, and proton pump as determinants of the sensitivity to MMC in vitro by using the selective inhibitors, ouabain, verapamil or AG-2000 (an active metabolite of Lansoplazole), respectively. PC-9 and PC-9/MC4 cell lines which are sensitive and resistant to MMC were used for these experiments. PC-9/MC4 was 9.4-fold more resistant to MMC than PC-9 cells. Relative resistance was not significantly changed by co-incubation with a non-cytotoxic dosage of these inhibitors. From these results, it was revealed that the active transport systems in cell membrane do not play a role in determining the sensitivity to MMC and the acquisition of resistance to MMC in PC-9 cell lines. Intracellular bioactivation may be an important factor to determine sensitivity to MMC in NSCLC cells under aerobic conditions.

Abrupt-onset diabetes mellitus in the elderly

We present three elderly Japanese patients with abrupt onset of diabetes mellitus: a 61-year-old male with a complete defect of insulin secretion without insulin resistance, a 60-year-old male with an incomplete defect of insulin secretion associated with insulin resistance, and a 69-year-old female with a complete defect of insulin secretion and insulin resistance. The findings in these cases indicate the heterogeneity in insulin secretion and sensitivity of abrupt onset diabetes mellitus in the elderly. The changes in insulin secretion and sensitivity over time due to glucose toxicity may at least partially explain the heterogeneity.

Four patients with polyendocrinopathy with associated pituitary hormone deficiency

Four cases of polyglandular endocrine disorders associated with pituitary hormone secretion failure are reported. Three of them had both insulin dependent diabetes mellitus (IDDM) and Hashimoto's disease. Each of these patients (cases 1-3) showed isolated deficiency of ACTH, TSH or gonadotropin, respectively. Another patient (case 4) had both Hashimoto's disease and isolated ACTH deficiency. Anti-pituitary antibody to AtT-20 cells was detected in case 1. Serum gamma-globulins from patients 1 and 4 attenuated corticotropin releasing hormone-induced ACTH release in monolayer cultured rat anterior pituitary cells. Gamma-globulins from patients 1 and 2 decreased baseline TSH release but stimulated baseline prolactin release in pituitary cell cultures. It is possible that pituitary hormone deficiency in these patients may be caused by autoimmune disorders.

Varied value of urinary N-acetyl-beta-D-glucosaminidase isoenzyme B in males of reproductive age

A reliable enzyme-linked immunosorbent assay designed to detect N-acetyl-beta-D-glucosaminidase isoenzyme B (NAG-B) was used to determine distribution and variation of urinary NAG-B in normal and pathologic urine. NAG-B values varied over a much broader range in urine from male than in that from female subjects under different conditions of sampling. Because NAG-B values are markedly high in the semen (5800.2 micrograms/liter on the average), contamination of the urine with NAG-B from genital tissues occurs at urination, when it enters urine containing NAG-B of renal origin. The clinical significance of NAG-B and total NAG enzymatic activity as a renal tubular marker should be carefully evaluated when analyzing urine of males from reproductive age.

DT-diaphorase as a determinant of sensitivity to adriamycin in non-small-cell lung-cancer cell lines

We have reported the establishment of a mitomycin-C (MMC)-resistant non-small-cell lung-cancer cell line, PC-9/MC4. As determined by an MTT assay, this resistant cell line was found to be 4 times more sensitive to adriamycin (ADM) than was the parental PC-9. There were no significant differences in sensitivity to etoposide, mitoxantrone, daunomycin, epirubicin, pirarubicin, 9-aminoanthracycline or 3'-deamino-3'-morpholino-13-deoxo-10-hydroxy carminomycin. These data suggest that neither qualitative or quantitative changes in DNA topoisomerase II nor the enhanced repair of DNA can explain the differing sensitivity to ADM observed. No significant differences were found in the accumulation of ADM and glutathione (GSH) in these cell lines. Although total glutathione-S-transferase (GST) activity in PC-9/MC4 cells was lower than that observed in PC-9 cells and treatment with ethacrynic acid (EA) reduced sensitivity to ADM in both cell lines, relative resistance was unaffected. NADH-cytochrome b5 reductase (B5R) activity in PC-9/MC4 cells showed a 3-fold greater decrease than that in PC-9 cells, and DT-diaphorase (DTD) activity in PC-9/MC4 cells showed an approximately 200-fold greater decrease than that in PC-9 cells. Addition of dicumarol, an inhibitor of DTD, decreased the sensitivity of ADM of PC-9 but not of PC-9/MC4. DTD activity in the PC-9 cell line was inhibited by treatment with dicumarol while in PC-9/MC4 it remained unchanged. These data suggest that DT-diaphorase is a determinant of sensitivity to ADM in the 2 cell lines.