Ethanolamine plasmalogens derived from whale brain stimulate both follicle-stimulating hormone and luteinizing hormone secretion by bovine gonadotrophs

Ethanolamine plasmalogens (EPls) are the only known ligands of a novel receptor, G protein-coupled receptor 61, and bovine brain EPls stimulate follicle-stimulating hormone (FSH) but not luteinizing hormone (LH), secreted by bovine gonadotrophs. We hypothesized that the brain EPls of whales (Balaenoptera edeni), another Cetartiodactyla with at least twice the lifespan of bovines, could stimulate FSH secretion by gonadotrophs. To test this hypothesis, bovine gonadotrophs (from approximately 2-year-old Japanese Black heifers) were cultured for 3.5 days and treated with increasing concentrations of brain EP1s from whales (approximately 22 years old). FSH and LH secretion was stimulated by all tested concentrations of whale EPls (p < 0.05). To clarify the important differences between bovine and whale EPls, we utilized two-dimensional liquid chromatography-mass spectrometry, which revealed 35 peaks. Among them, we observed significant differences between 12 EPl molecular species. Additionally, we identified differentially expressed genes for enzymes involved in EPl synthesis or degradation in the hypothalamus of young heifers and old cows (approximately 10 years old) as compared to whales (approximately 28 years old) via deep sequencing of the transcriptome. We conclude that whale brains contain unique EPls that stimulate both FSH and LH secretion by bovine gonadotrophs.

Cardiometabolic predictors of quantitative high-risk plaque features in a diverse patient population

Background/Introduction

Little is known about the prevalence of high-risk plaque features or cardiometabolic predictors in diverse patient populations with underrepresented minorities, in the setting of stable chest pain.

Purpose

The goals of our study are to 1) describe plaque characteristics in a diverse patient population with underrepresented minorities and 2) characterize cardiometabolic risk factors associated with high prevalence of high-risk quantitative low attenuation noncalcified plaque (LDNCP) burden.

Methods

Our study included patients with chest pain undergoing CCTA between June 2016 and October 2021 for stable chest pain, who had a complete cardiometabolic panel including lipoprotein(a) and lipid panel, and at least one blood pressure recording before CCTA. Patients with prior PCI or CABG where excluded. CACS was performed before CCTA as per Agatston method and quantified in Agatston Units (AU). Stenosis was graded as per SCCT guidelines by cardiologists and radiologists with level 3 cardiac CT expertise. Plaque measurements were performed using previously validated semiautomated software (AutoPlaque version 2.5) in all patients with CAD-RADS &gt;0 by expert readers blinded from patients' characteristics. Coronary atherosclerotic plaque volumes were measured. Independent predictors for plaque on CCTA among patients were examined using Wilcox multivariate logistic regression.

Results

A total of 227 consecutive patients were included in our study (see table; age 55.00 [47.50–62.00] years, 63% female, 16% diabetes, 44% hypertension, 40% hyperlipidemia and 32% with current or previous smoking history). Majority of patients were Hispanic (64%) and the rest were Black (27%), White (6%) and Asian (3%).

Patients with LDNCP burden &gt;4% were older (60.00 [52.00–66.50] vs 53.00 [43.75–61.00]; p&lt;0.001), more likely to be diabetic (27.7 vs 11.5%; p=0.005), hypertensive (67.7 vs 33.8%; p&lt;0.001), hyperlipidemic (64.6 vs 29.9%; p&lt;0.001) and present smokers (31.3 vs 13.9%; p=0.003). Almost all patients (63/67) with LDNCP burden &gt;4% had non-obstructive disease (CAD-RADS&lt;4).

Patient with LDNCP burden &gt;4% were more likely to be on statin therapy (46.0 vs 30.4%; p=0.041). There was no differences in ethnicity, hemoglobin A1C, TC, LDL-C, HLD-C, TGs, lipoprotein(a), SBP or DBP.

By logistic regression analysis, age (OR [CI]: 1.06 [1.01–1.08]), hypertension (2.20, [1.06–4.63]) and hyperlipidemia (2.73 [1.37–5.47]) increased the likelihood of LDNCP burden &gt;4%, but not Lipoprotein (a)&gt;175 nmol/L (OR [CI]: 1.07 [0.48–2.31].

Conclusions

In our cohort of patients with high number of unrepresented minorities presenting with stable chest pain, almost all patients (94%) with LDNCP burden &gt;4% had non-obstructive CAD (CAD-RADS&lt;4). There were no differences in prevalence of LDNCP or CAD-RADS among different ethnic groups. Age, hypertension and hyperlipidemia, were the cardiometabolic factors related to LDNCP burden &gt;4%.

Funding Acknowledgement

Type of funding sources: None.

Pulmonary artery pressure-guided therapy in patients with heart failure using the CardioMEMS device and HF readmissions: analysis of the National Readmissions Database

Background

Pulmonary artery pressure (PAP)-guided therapy in patients with heart failure (HF) using the CardioMEMS device (CMM), an implantable PAP sensor, has shown to reduce HF hospitalizations in previous studies. We sought to evaluate the clinical benefit of the CMM device in regard to 30-day, 90-day and 180-day readmission rates in real-world usage.

Methods

We queried the National Readmission Database (NRD) to identify patients who underwent CMM implantation (ICD 9 & 10 codes) between the years 2014 to 2019 and studied their HF readmissions. We compared CMM patients and their readmissions with a matched cohort of patients with HF without CMM. Multivariable Cox regression analysis was performed to adjust for other predictors of readmissions.

Results

Prior to matching we identified 5,326,530 weighted HF patients without CMM and 1842 patients with CMM. After propensity score matching for several patients and hospital related characteristics, the cohort consisted of 1839 patients with CMM and 1924 with HF without CMM. Before matching, CMM patients were younger (67.0±13.5 years vs 72.3±14.1 years, P&lt;0.001), more frequently males (62.7% vs 51.5%, P&lt;0.001), with higher rates of prior percutaneous coronary intervention (16.9% vs 13.2%, P=0.002), peripheral vascular disease (29.6% vs 17.8%, P&lt;0.001), pulmonary circulatory disorder (38.7% vs 23.2%, P&lt;0.001), atrial fibrillation (51.2% vs 45.3%, P=0.002), prior left ventricular assist device (1.8% vs 0.2%, P&lt;0.001), high income (32.2% vs 16.4%, P&lt;0.001) and acute kidney disease (43.8% vs 29.9%, P&lt;0.001). Readmission rates at 30-days were 17.3% vs. 20.9% for patients with vs. without CMM respectively and remained statistically significant after matching (17.3% vs. 21.5%, p=0.002). The rates of 90-day (29.1% vs 36.5%, p=0.002) and 180-day (39.6% vs. 46.6%, p=0.009) readmissions were lower in the CMM group. In a multivariable regression model, CMM was associated with lower risk of readmissions (HR, 0.75, 95% CI 0.63–0.89, p=0.001).

Conclusion

The CMM device was associated with reduced HF rehospitalization rates in a nationally representative cohort of HF patients.

Funding Acknowledgement

Type of funding sources: None.

Comparison of valve durability among different transcatheter and surgical aortic valve prostheses: a network meta-analysis

Background

Durability of different transcatheter heart valve (THV) is critical as the indication of transcatheter aortic valve replacement (TAVR) expands to patients with longer life-expectancy.

Purpose

We aimed to compare the durability of THV systems (balloon-expandable [BE] and self-expandable [SE]) and surgical aortic valve replacement (SAVR) prosthesis.

Methods

PUBMED and EMBASE were searched through February 2021 for randomized trials investigating parameters of valve durability after TAVR and/or SAVR in severe aortic stenosis. A network meta-analysis using random-effect model was performed. Synthesis was performed with 5-year follow-up data for echocardiographic outcomes and longest available follow-up data for clinical outcomes.

Results

Ten trials with a total of 9,388 patients (BE-THV: 2,562; SE-THV 2,863; SAVR:3,963) were included. Follow-up ranged from 1–6 years. SE-THV demonstrated significantly larger effective orifice area, lower mean aortic valve gradient (AVG), and less increase in mean AVG at 5-years compared to BE-THV and SAVR (Figure 1). Structural valve deterioration (SVD) was less frequent in SE-THV compared to BE-THV and SAVR (HR 0.14, 95% CI 0.07–0.27; HR 0.34, 95% CI 0.24–0.47, respectively) (Figure 1). Total moderate-severe aortic regurgitation and re-intervention was more frequent in BE-THV (HR 4.21, 95% CI 2.40–7.39; HR 2.22, 95% CI 1.16–4.26, respectively) and SE-THV (HR 7.51, 95% CI 3.89–14.5; HR 2.86, 95% CI 1.59–5.13, respectively) compared to SAVR.

Conclusion

TAVR with SE-THV demonstrated favorable forward-flow hemodynamics and lowest risk of SVD compared to BE-THV and SAVR at mid-term. However, both THV systems suffer an increased risk of aortic regurgitation and re-intervention, and long-term data from newer generation valve is warranted.

Funding Acknowledgement

Type of funding sources: None.

The 30-day readmission of same-day discharge following pulmonary vein isolation for atrial fibrillation: a propensity score-matched analysis from National Readmission Database

Introduction

The complication rate following pulmonary vein isolation (PVI) for atrial fibrillation (AF) has improved in recent decades with the increasing number of PVI worldwide. The effectiveness and safety of same-day discharge for PVI has not been elucidated well using a large nationwide database.

Purpose

The aim of our study was to evaluate the readmission rates within 30-days among patients receiving PVI for AF with the same-day discharge compared with the usual overnight observation protocol.

Methods

We performed a retrospective cohort study using the US Nationwide Readmission Database. Patients were divided into the two groups: the same-day discharge group and the overnight observation group (those who stayed at least one night following PVI). The primary outcome was an all-cause 30-day readmission rate following discharge in patients receiving PVI and a secondary outcome of total healthcare cost. A 1:3 propensity score matching was used to compare the safety within both protocols. Patients with peri-procedural complications such as pericardial, vascular, bleeding requiring transfusion, were excluded from the analysis.

Result

Among 30,776 patients (mean 67.2±11.4 years, 18,004 male (58.5%)) who received PVI from 2016 through 2018, 440 (1.42%) patients were discharged the same-day following PVI (same-day discharge group), and the remaining 30,336 patients stayed at least one night in the hospital (the overnight observation group). A propensity score analysis generated 1,751 matched pairs (440 in the same-day discharge group; 1311 in the observation overnight group). The 30-day readmission following discharge was not significantly higher in the same-day discharge group, compared to the overnight observation group (same-day discharge vs. overnight observation group: 12.7% vs. 9.7%, p=0.23; odds ratio [OR]:1.39, 95%confidence interval [CI]: 0.87–2.22) (Figure). Healthcare cost was significantly higher in the overnight observational group. ($25,237±14,036 vs. $30,749±16,383; p&lt;0.01).

Conclusion

In this large nationwide study using a propensity score matching analysis, there was no significant difference in 30-day readmission rates following the same-day discharge in patients receiving PVI for AF compared with the overnight observation protocol.

Funding Acknowledgement

Type of funding sources: None.

P2Y12 inhibitors in patients with non-ST-segment elevation acute coronary syndrome: systematic review and network meta-analysis of randomized trials

Background

Based on a recent randomized control trial (RCT), prasugrel is recommended in preference to ticagrelor for patients with non-ST-segment elevation ACS (NSTE-ACS), however, limited data exists.

Objectives

We aimed to investigate the effect of P2Y12 inhibitors on ischemic and bleeding events in NSTE-ACS patients.

Methods

Clinical trials enrolling NSTE-ACS patients were identified and relevant data was extracted. We performed a network meta-analysis on efficacy and safety outcomes.

Results

Our study including a total of 37, 268 patients with NSTE-ACS from 11 RCTs. Prasugrel decreased major adverse cardiovascular events (MACE) when compared to clopidogrel (Hazard ratio (HR): 0.84; 95% confidence interval (CI) [0.71–0.99]). For MACE, prasugrel showed the highest likelihood of event reduction (P-score=0.97) in comparison to ticagrelor (P-score=0.29) and clopidogrel (P-score=0.24). Prasugrel decreased myocardial infarction (HR: 0.82; 95% CI [0.68–0.99]) but increased major bleeding without statistical significance (HR: 1.30; 95% CI [0.97–1.74]) when compared to clopidogrel. Ticagrelor reduced cardiovascular death (HR: 0.79; 95% CI [0.66–0.94]) but increased major bleeding (HR: 1.33; 95% CI [1.00–1.77], p=0.049) in comparison to clopidogrel. There was no significant difference between prasugrel and ticagrelor for each endpoint, but prasugrel had higher likelihood of event reduction than ticagrelor for all endpoints except cardiovascular death.

Conclusions

Prasugrel and ticagrelor had comparable risk for each endpoint, but prasugrel had the highest probability being the best treatment in reducing the primary endpoint. This study highlights the need for further large-scale RCTs to investigate the optimal P2Y12 inhibitor selection in NSTE-ACS patients.

Funding Acknowledgement

Type of funding sources: None.

Mortality after transcatheter versus surgical aortic valve replacement: an updated meta-analysis of randomised trials

Background

To determine whether transcatheter aortic valve implantation (TAVI) improves early (30-day) and midterm (1-year) mortality compared with surgical aortic valve replacement (SAVR), we performed an updated meta-analysis of all the currently available randomised controlled trials (RCTs).

Methods

To identify all RCTs providing both 30-day and 1‑year mortality after TAVI versus SAVR, PubMed and ClinicalTrials.gov were searched up to and including July 2019. A risk difference (RD) and its 95% confidence interval were generated using data of prespecified outcomes in both the TAVI and SAVR groups. Study-specific estimates were pooled using inverse variance-weighted averages of RDs in the random-effects model.

Results

We identified seven eligible high-quality RCTs including a total of 7631 as-treated patients. Pooled analyses demonstrated significantly lower 30-day (RD −0.60%; p = 0.046) and 1‑year all-cause mortality (RD −1.12%; p = 0.03) after TAVI than after SAVR. No funnel plot asymmetry was detected for 30-day and 1‑year mortality. Meta-regression analyses indicated that RDs of 30-day and 1‑year mortality between TAVI and SAVR were not modulated by mean Society of Thoracic Surgeons Predicted Risk of Mortality score. Bleeding complications at 30 days and 1 year and stage 2/3 acute kidney injury at 30 days were significantly less frequent after TAVI than after SAVR, whereas major vascular complications and new permanent pacemaker implantation at 30 days and 1 year were significantly more frequent after TAVI than after SAVR.

Conclusion

The best evidence from the present meta-analysis of all the currently available RCTs suggests that TAVI may reduce 30-day and 1‑year all-cause mortality compared with SAVR.

Electronic supplementary material

The online version of this article (10.1007/s12471-020-01378-1) contains supplementary material, which is available to authorized users.

Autotransplantation of a maxillary first premolar to replace an ankylosed maxillary incisor: 7-year follow-up

AIM

To present the combined endodontic, surgical and orthodontic treatment of an autotransplanted maxillary first premolar for the replacement of an ankylosed maxillary incisor.

SUMMARY

This case report describes the autotransplantation of a maxillary premolar after the extraction of an ankylosed incisor in a 13-year-old boy. To allow better adaptation of the donor tooth, the buccal root of the first premolar was removed using a diamond bur and the denuded root site was filled with acid-etched composite resin. The palatal root canal was dressed with calcium hydroxide for 2 months before filling with gutta-percha. Autotransplantation of a remodelled maxillary first premolar was achieved to substitute for the ankylosed maxillary central incisor. Orthodontic treatment was performed to correct an Angle Class II malocclusion. Seven years after root canal treatment, the autotransplanted tooth and supporting tissues appeared healthy both clinically and radiographically and were functioning well.

KEY LEARNING POINTS

• Autotransplantation is a viable option for the treatment of a missing tooth or for the replacement of a traumatized tooth when there is a donor tooth available. • Autotransplantation of a premolar for replacement of a missing anterior tooth is sometimes a suitable alternative to conventional prosthetic rehabilitation or implant treatment in young individuals. • Proper combined endodontic and orthodontic treatment of autotransplanted teeth might be possible without periodontal complications.

Equivocal colonic carcinogenicity of Aloe arborescens Miller var. natalensis berger at high-dose level in a Wistar Hannover rat 2-y study

A 2-y carcinogenicity study of Aloe, Aloe arborescens Miller var. natalensis Berger, a food additive, was conducted for assessment of toxicity and carcinogenic potential in the diet at doses of 4% or 0.8% in groups of male and female Wistar Hannover rats. Both sexes receiving 4% showed diarrhea, with loss of body weight gain. The survival rate in the 4% female group was significantly increased compared with control females after 2 y. Hematological and biochemical examination showed increase of RBC, Hb, and Alb in the 4% males. The cause of these increases could conceivably have been dehydration through diarrhea. AST and Na were significantly decreased in the males receiving 4%, and Cl was significantly decreased in both 4% and 0.8% males. A/G was significantly increased in the 4% females, and Cl was significantly decreased (0.8%) in the female group. Histopathologically, both sexes receiving 4% showed severe sinus dilatation of ileocecal lymph nodes, and yellowish pigmentation of ileocecal lymph nodes and renal tubules. Adenomas or adenocarcinomas in the cecum, colon, and rectum were observed in 4% males but not in the 0.8% and control male groups. Similarly, in females, adenomas in the colon were also observed in the 4% but not 0.8% and control groups. In conclusion, Aloe, used as a food additive, exerted equivocal carcinogenic potential at 4% high-dose level on colon in the 2-y carcinogenicity study in rats. Aloe is not carcinogenic at nontoxic-dose levels and that carcinogenic potential in at 4% high-dose level on colon is probably due to irritation of the intestinal tract by diarrhea.

Antioxidant effects of flavonoids used as food additives (purple corn color, enzymatically modified isoquercitrin, and isoquercitrin) on liver carcinogenesis in a rat medium-term bioassay

To clarify the effects of purple corn color, enzymatically modified isoquercitrin (EMIQ), and isoquercitrin (IQ), registered as natural food additives in Japan, on liver carcinogenesis in vivo, a medium-term bioassay was employed. A total of 100 male F344 rats were divided into 5 groups; groups 1 to 4 were given a single intraperitoneal injection of diethylnitrosamine (200 mg/kg b.w.) on day 1. From weeks 2 to 8, they were administered basal diet purple corn color, EMIQ, or IQ as containing test chemicals at doses of 1.0% (groups 1 and 5), 0.1% (group 2), 0.01% (group 3), or 0% (group 4) (experiments 1, 4, and 5). All rats were subjected to two-thirds partial hepatectomy at week 3 and were sacrificed at week 8. Purple corn color exerted no significant modifying effects on GST-P positive foci, preneoplastic foci, development in the liver. However, serum of rats treated with purple corn color provided evidence of antioxidant power significantly by potential antioxidant (PAO) test in vivo (experiment 2). And microarray analyses showed purple corn color to induce RNA expression such as P450 (cytochrome) oxidoreductase, phosphatidylinositol 3-kinase, and phospholipase A2 (experiment 3). Higher doses of EMIQ or IQ with strong antioxidant power in vivo by PAO test treated groups were correlated with smaller numbers of GST-P positive foci, with Spearman's rank correlation coefficients of P= 0.002 and P= 0.049, respectively (experiments 4 and 5). Therefore, the tested food additives may be effective as antioxidants in vivo and have chemopreventive potential against liver preneoplastic lesion development.

Endodontic and orthodontic treatment of a cross-bite fused maxillary lateral incisor

AIM

To describe combined endodontic and orthodontic treatment of a maxillary lateral incisor fused with a supernumerary.

SUMMARY

A rare case is presented in which combined endodontic and orthodontic treatment was performed on a cross-bite fused tooth. Clinical and radiographic examination showed the maxillary lateral incisor fused with a supernumerary and an impacted canine. The fused tooth required nonsurgical and surgical endodontic treatment for functional and aesthetic reasons. The root canals were dressed with calcium hydroxide for 2 months before they were obturated with thermoplasticized injectable gutta-percha. Then, the distal part of the fused tooth was removed and the mesial part of the tooth was replanted and fixed. Three months after the completion of orthodontic therapy, the impacted canine erupted between the remaining tooth and the first premolar. Recall examination, 3 years after completion of root canal treatment, showed clinical and radiographic evidence of healing.

KEY LEARNING POINTS

Fusion has been described as a development anomaly characterized by the union of two adjacent teeth. Proper combined endodontic and orthodontic treatment resulted in maintaining one tooth half and solving the aesthetic and functional problem of a fused tooth.

Chemoprevention of large bowel carcinogenesis; the role of control of cell proliferation and significance of beta-catenin-accumulated crypts as a new biomarker

Control of cell proliferation is important for cancer prevention since cell proliferation has essential roles in carcinogenesis in the processes of both initiation and promotion. In large bowel carcinogenesis, carcinogens produce hyperproliferation of cells in the target sites and the cell proliferation persists even after the cessation of carcinogen exposure. Chemopreventive agents principally control the increased cell proliferation when given in the initiation as well as post-initiation phases. Aberrant crypt foci (ACF) which appear soon after carcinogen exposure in large bowel carcinogenesis in rodents have been used as a reliable biomarker for screening of potential chemopreventive agents. Recently, our group demonstrated the presence of probable premalignant lesions with frequent beta-catenin gene mutations and accumulation of the corresponding protein in the colonic epithelium of rats given a large bowel carcinogen. Such early-appearing lesions lack the morphological appearance of ACF. Expression of these beta-catenin-accumulated crypts (BCAC) is markedly suppressed by a chemopreventive cyclooxygenase-2 inhibitor, celecoxib. BCAC are suggested to be more reliable biomarkers than ACF for screening effective chemopreventive agents for colorectal cancer and for investigating the mode of action of the agents.

Downregulation of vascular soluble guanylate cyclase induced by high salt intake in spontaneously hypertensive rats

1. Cyclic guanosine monophosphate (cyclic GMP)-mediated mechanism plays an important role in vasodilatation and blood pressure regulation. We investigated the effects of high salt intake on the nitric oxide (NO) - cyclic GMP signal transduction pathway regulating relaxation in aortas of spontaneously hypertensive rats (SHR). 2. Four-week-old SHR and normotensive Wistar-Kyoto rats (WKY) received a normal salt diet (0.3% NaCl) or a high salt diet (8% NaCl) for 4 weeks. 3. In aortic rings from SHR, endothelium-dependent relaxations in response to acetylcholine (ACh), adenosine diphosphate (ADP) and calcium ionophore A23187 were significantly impaired by the high salt intake. The endothelium-independent relaxations in response to sodium nitroprusside (SNP) and nitroglycerin were also impaired, but that to 8-bromo-cyclic GMP remained unchanged. On the other hand, high salt diet had no significant effects on the relaxations of aortic rings from WKY. 4. In aortas from SHR, the release of NO stimulated by ACh was significantly enhanced, whereas the production of cyclic GMP induced by either ACh or SNP was decreased by the high salt intake. 5. Western blot analysis showed that the protein level of endothelial NO synthase (eNOS) was slightly increased, whereas that of soluble guanylate cyclase (sGC) was dramatically reduced by the high salt intake. 6. These results indicate that in SHR, excessive dietary salt can result in downregulation of sGC followed by decreased cyclic GMP production, which leads to impairment of vascular relaxation in responses to NO. It is notable that chronic high salt intake impairs the sGC/cyclic GMP pathway but not the eNOS/NO pathway.

Flk-1 specific kinase inhibitor (SU5416) inhibited the growth of GS-9L glioma in rat brain and prolonged the survival

BACKGROUND

Accumulating evidences suggest that tumor growth and metastasis depend on angiogenesis. At present, plenty of efforts are made to discover a chemical compound that specifically inhibits tumor angiogenesis either by reducing pro-angiogenic factor or increasing anti-angiogenic factors.

OBJECT

SU5416, a novel, synthetic, potential inhibitor of angiogenesis specifically blocks the Flk-1/KDR tyrosine kinase activity. In vivo effect of SU5416 in the treatment of intracranial tumors has not been previously described.

METHODS

We transplanted GS-9L cells into the right caudate nucleus of male Fisher 344 rats and administrated SU5416 intraperitoneally (i.p.) to investigate the impact of SU5416 on tumor angiogenesis and growth in vivo. Starting on Day 1 or Day 8, forty-two animals were treated with SU5416 at three different doses (e.g. 12.5, 25.0 and 50.0 mg/kg body weight) via i.p. injection every day until the end-point. As a control, seven animals received no treatment and after implant fourteen animals were treated with vehicle (DMSO) only.

RESULTS

SU5416 prolonged the survival in the treated groups without any significant systemic adverse effect. Median survival in the treated group started on Day.1 was statistically longer compared to that in the control groups (p<0.01). Histological analysis of the treated tumors showed an increase in necroses and reduced in vascularity compared to the control tumors. Furthermore, the number of apoptotic cells increased in the treated tumors on a TUNEL stain.

CONCLUSION

Small molecular compounds, such as SU5416 may be useful therapeutics that specifically inhibits the enzymatic activity of Flk-1 kinase and downstream events of tumor angiogenesis.

Quantitative evaluation of thalami and basal ganglia in infants with periventricular leukomalacia

Quantitative analyses of cross-sectional areas of the thalami, caudate nuclei, and lentiform nuclei were performed in 29 preterm infants (16 males, 13 females; mean age 29.6 weeks, age range 27 to 24 weeks,) with periventricular leukomalacia (PVL). MRI was carried out in the infants between 9 and 18 months of corrected age and in 16 control infants. Bilateral thalami, caudate nuclei, lentiform nuclei, cerebral hemispheres, and cerebellum were measured by computer. Ratios of the areas of the thalami (Th), caudate nuclei (Ca), lentiform nuclei (Le), and cerebral hemispheres (CH) to that of the cerebellum (Ce) were calculated in each infant. The ratio of Th:Ce was significantly smaller in infants with moderate and severe PVL than in the control group bilaterally. Abnormal intensity areas were not observed in the thalami in any infants with PVL. CH:Ce was also smaller in infants with severe PVL than in the control group. No significant difference was observed between the groups in ratios Le:Ce or Ca:Ce. Results of our study suggest that the volume of the thalami is reduced and that thalamic involvement is present in infants with white matter lesions who have moderate to severe PVL.

Suppression of occurrence and advancement of beta-catenin-accumulated crypts, possible premalignant lesions of colon cancer, by selective cyclooxygenase-2 inhibitor, celecoxib

Suppression of occurrence and advancement of premalignant lesions is important for cancer prevention. Our previous studies clarified that beta-catenin-accumulated crypts, independent of aberrant crypt foci (ACF), are probably direct precursors of colon cancers in rats. Here we investigated the effects of a selective cyclooxygenase-2 inhibitor, celecoxib, on the development of beta-catenin-accumulated crypts in comparison with those on ACF. Male F344 rats were divided into 4 groups. Groups 1 - 3 were administered azoxymethane (AOM) s.c. at a dose of 15 mg / kg body weight, once weekly for 3 weeks to induce beta-catenin-accumulated crypts. Groups 2 and 3 also received experimental diet containing celecoxib (500 and 1500 ppm, respectively) for 8 weeks, starting a week before the first dosing of AOM. At termination, the frequency and crypt multiplicity (number of crypts / lesion) of beta-catenin-accumulated crypts of groups 2 and 3 were significantly less than that of group 1. Furthermore, numbers of silver-stained nucleolar organizer regions (AgNORs) / nucleus in beta-catenin-accumulated crypts were also decreased by exposure to celecoxib. In this study, celecoxib had greater effects on the frequency and growth of beta-catenin-accumulated crypts than on those of ACF. These findings represent additional evidence that beta-catenin-accumulated crypts are premalignant lesions of colon cancer. The results also suggest that beta-catenin-accumulated crypts could be a novel target for evaluation of possible chemopreventive agents against colon carcino-genesis, and indicate that possible chemopreventive effects of celecoxib on the initial stage of colon carcinogenesis may be related to modulation of cell proliferation activity in such early lesions.

Its8, a fission yeast homolog of Mcd4 and Pig-n, is involved in GPI anchor synthesis and shares an essential function with calcineurin in cytokinesis

In fission yeast, calcineurin is required for cytokinesis and ion homeostasis; however, most of its physiological roles remain obscure. To identify genes that share an essential function with calcineurin, we screened for mutations that confer sensitivity to the calcineurin inhibitor FK506 and high temperature and isolated the mutant its8-1. its8(+) encodes a homolog of the budding yeast MCD4 and human Pig-n that are involved in glycosylphosphatidylinositol (GPI) anchor synthesis. Consistently, reduced inositol labeling of proteins suggested impaired GPI anchor synthesis in its8-1 mutants. The temperature upshift induced a further decrease in inositol labeling and caused dramatic increases in the frequency of septation in its8-1 mutants. BE49385A, an inhibitor of MCD4 and Pig-n, also increased the septation index of the wild-type cell. Osmotic stabilization suppressed these morphological defects, indicating that cell wall weakness caused by impaired GPI anchor synthesis resulted in abnormal cytokinesis. Furthermore, calcineurin-deleted cells exhibited hypersensitivity to BE49385A, and FK506 exacerbated the cytokinesis defects of the its8-1 mutant. Thus, calcineurin and Its8 may share an essential function in cytokinesis and cell viability through the regulation of cell wall integrity.

Sequential analysis of morphological and biological properties of beta-catenin-accumulated crypts, provable premalignant lesions independent of aberrant crypt foci in rat colon carcinogenesis

Our previous study (Cancer Res., 60: 3323-3327, 2000) showed that frequent beta-catenin gene mutations are present in beta-catenin-accumulated crypts, which occur early in rodent colonic carcinogenesis, with a lack of the appearance of aberrant crypt foci (ACF). To clarify the nature of such lesions, we performed a sequential analysis of the morphological and biological properties of beta-catenin-accumulated crypts. Azoxymethane was administered s.c. to male F344 rats (15 mg/kg body weight) once a week for 3 weeks, and the animals were sacrificed at 5, 10, and 20 weeks after the carcinogen treatment. Both the number of crypts/lesion and the diameter of beta-catenin-accumulated crypts were significantly increased with time courses of 5, 10, and 20 weeks from carcinogen exposure (P < 0.01). Likewise, the histological abnormality in those crypts, assessed by semiquantitative analyses, was also increased with time (P < 0.01). Conversely, ACF did not show any increase in histological abnormality during the time course and maintained a monotonous histology throughout the experiment. The histological abnormality score for beta-catenin-accumulated crypts was significantly higher than for ACF at every time point (P < 0.001). The number of AgNOR/nucleus in beta-catenin-accumulated crypts was significantly higher than in ACF (P < 0.001). Beta-catenin-accumulated crypts were accompanied frequently by Paneth cells and had decreased hexosaminidase activity. Such data, together with the results in our previous report, strongly suggest that beta-catenin-accumulated crypts, which are independent of ACF, are truly premalignant lesions for colon cancer.

The inhibitory effects of mangiferin, a naturally occurring glucosylxanthone, in bowel carcinogenesis of male F344 rats

Mangiferin, 1,3,6,7-tetrahydroxyxanthone-C2-beta-D-glucoside, is one of xanthone derivatives and C-glucosylxanthones, is widely distributed in higher plants and is one of constituents of folk medicines. Recent studies showed that mangiferin has a potential as an anti-oxidant and an anti-viral agent. In this study, we examined the effects of mangiferin in rat colon carcinogenesis induced by chemical carcinogen, azoxymethane (AOM). We performed two experiments: a short-term assay to investigate the effects of mangiferin on the development of preneoplastic lesions by AOM, aberrant crypt foci (ACF), and the following long-term assay for the influence of mangiferin on tumorigenesis induced by AOM. In the short-term assay, 0.1% mangiferin in a diet significantly inhibited the ACF development in rats treated with AOM compared to rats treated with AOM alone (64.6+/-22.0 vs. 108.3+/-43.0). In the long-term assay, the group treated with 0.1% mangiferin in initiation phase of the experimental protocol had significantly lower incidence and multiplicity of intestinal neoplasms induced by AOM (47.3 and 41.8% reductions of the group treated with AOM alone for incidence and multiplicity, respectively). In addition, the cell proliferation in colonic mucosa was reduced in rats treated with mangiferin (65-85% reductions of the group treated with AOM alone). These results suggest that mangiferin has potential as a naturally-occurring chemopreventive agent.

Molecular genetic analysis of the calcineurin signaling pathways

Calcineurin is a Ca2+- and calmodulin-regulated protein phosphatase that is important in Ca2+-mediated signal transduction. Recent application of the powerful techniques of molecular genetics has demonstrated that calcineurin is involved in the regulation of critical biological processes such as T cell activation, muscle hypertrophy, memory development, glucan synthesis, ion homeostasis, and cell cycle control. Notably, specific transcription factors have been shown to play a key role in regulating these functions, and their calcineurin-mediated dephosphorylation and nuclear translocation appear to be a central event in the signal transduction pathways. This review focuses on recent progress in these areas and discusses the evidence for cross-talk between calcineurin and other signaling pathways.

Intravascular ultrasound imaging before and after angioplasty for stenosis of arteriovenous fistulae in haemodialysis patients

BACKGROUND

Complications of haemodialysis vascular access have emerged as a major cause of patient morbidity. Intravascular ultrasound imaging is a new technical modality providing visualization of the vessel lumen and wall structure in a cross-sectional fashion. Percutaneous transluminal angioplasty has long been used in the treatment of stenoses of arteriovenous fistulae. However, there is no detailed quantitative information on the stenotic lesion and the morphological change by angioplasty.

METHODS

Intravascular ultrasound studies were performed in 40 haemodialysis patients with 63 stenoses in arteriovenous fistulae who had percutaneous transluminal angioplasty. The patients were qualitatively and quantitatively evaluated for echogenic patterns and morphological changes before and after angioplasty.

RESULTS

Morphological plaque features in stenotic lesions were classified as 37 soft (58%), five hard (8%), 20 mixed (32%), and one calcified sites. Plaque fractures after angioplasty were detected in 45/63 (71%) instances. The lumen cross-sectional area was found to be dilated approximately threefold (from 3.8+/-2.4 to 11.1+/-4.5 mm(2)) and the external elastic membrane cross-sectional area was dilated approximately twofold (from 11.1+/-5.3 to 19.8+/-8.1 mm(2)) after angioplasty.

CONCLUSION

These results indicate that intravascular ultrasound allows both qualitative and quantitative assessments of arteriovenous fistulae in haemodialysis patients. The results further suggest that the mechanism of expansion of arteriovenous fistulae stenoses by percutaneous transluminal angioplasty involves stretching of the vessel wall as well as plaque fractures.

Phosphatidylinositol 4-phosphate 5-kinase Its3 and calcineurin Ppb1 coordinately regulate cytokinesis in fission yeast

The ppb1(+) gene encodes a fission yeast homologue of the mammalian calcineurin. We have recently shown that Ppb1 is essential for chloride ion homeostasis, and acts antagonistically with Pmk1 mitogen-activated protein kinase pathway. In an attempt to identify genes that share an essential function with calcineurin, we screened for mutations that confer sensitivity to the calcineurin inhibitor FK506 and high temperature, and isolated a mutant, its3-1. its3(+) was shown to be an essential gene encoding a functional homologue of phosphatidylinositol-4-phosphate 5-kinase (PI(4)P5K). The temperature upshift or addition of FK506 induced marked disorganization of actin patches and dramatic increase in the frequency of septation in the its3-1 mutants but not in the wild-type cells. Expression of a green fluorescent protein-tagged Its3 and the phospholipase Cdelta pleckstrin homology domain indicated plasma membrane localization of PI(4)P5K and phosphatidylinositol 4,5-bisphosphate. These green fluorescent protein-tagged proteins were concentrated at the septum of dividing cells, and the mutant Its3 was no longer localized to the plasma membrane. These data suggest that fission yeast PI(4)P5K Its3 functions coordinately with calcineurin and plays a key role in cytokinesis, and that the plasma membrane localization of Its3 is the crucial event in cytokinesis.

Tol1, a fission yeast phosphomonoesterase, is an in vivo target of lithium, and its deletion leads to sulfite auxotrophy

Lithium is the drug of choice for the treatment of bipolar affective disorder. The identification of an in vivo target of lithium in fission yeast as a model organism may help in the understanding of lithium therapy. For this purpose, we have isolated genes whose overexpression improved cell growth under high LiCl concentrations. Overexpression of tol1(+), one of the isolated genes, increased the tolerance of wild-type yeast cells for LiCl but not for NaCl. tol1(+) encodes a member of the lithium-sensitive phosphomonoesterase protein family, and it exerts dual enzymatic activities, 3'(2'),5'-bisphosphate nucleotidase and inositol polyphosphate 1-phosphatase. tol1(+) gene-disrupted cells required high concentrations of sulfite in the medium for growth. Consistently, sulfite repressed the sulfate assimilation pathway in fission yeast. However, tol1(+) gene-disrupted cells could not fully recover from their growth defect and abnormal morphology even when the medium was supplemented with sulfite, suggesting the possible implication of inositol polyphosphate 1-phosphatase activity for cell growth and morphology. Given the remarkable functional conservation of the lithium-sensitive dual-specificity phosphomonoesterase between fission yeast and higher-eukaryotic cells during evolution, it may represent a likely in vivo target of lithium action across many species.

Markers for bone metabolism in a long-lived case of thanatophoric dysplasia

We report a male patient with type 1 thanatophoric dysplasia, now eight years old, having a mutation in the FGFR3 gene. Radiological examination at birth revealed that the ribs and the bones of the extremities were very short and vertebral bodies were greatly reduced in height with wide intervertebral spaces. The femurs were shaped like French telephone receivers. Because of respiratory insufficiency due to the narrow thorax, the patient has been intubated and supported by continuous mechanical ventilation since the day after birth. Since 5 years of age, despite sufficient caloric intake, his body weight never increased above 4700 g, body height 49.0 cm, head circumference 46.1 cm, and chest circumference 35.8 cm. Acanthosis nigricance and huge bilateral coral-like urolithiases has been present. His mental development was severely retarded but he was able to make emotional expressions. Although developments in motor functions could not be assessed, his neurodevelopmental milestones in social relationships and language perception seemed to be at the level of a 10 to 12 month old. His bone maturation was also severely retarded. All of the assays of his serum and urinary bone formation- or resorption-related substances were within normal limits for age. Therefore, bone formation as well as bone resorption activities seemed normal and not responsible for his growth retardation.

[Phosphate kinetics in patients on chronic hemodialysis]

To investigate the phosphate kinetics in hemodialysis (HD), 8 patients in a stable condition, who were receiving HD three times a week for 4 hours per session, were investigated. Plasma phosphate was under 7 mg/dl, and residual renal function had almost disappeared. Dialysate containing phosphate was prepared by adding Na2HPO4 using a micro-infusion pump from the inlet of single pass dialysate in the individual dialysate delivery system. In the first week, Na2HPO4 was not added as the control period. In the second session of the second and third week, Na2HPO4 was added to give a phosphate concentration of 1.0 and 2.0 mmol/l in the dialysate, respectively. Total phosphate mass removal was 777 +/- 46.64 mg in the control period, 403 +/- 67.21 mg in the second week, and -230 +/- 214.8 mg in the third week. Total phosphate mass removal in the second and third week was significantly lower than that of the control period. Plasma phosphate concentration was significantly decreased after the HD compared with before the HD in the control and second week. There was no significant difference in plasma phosphate concentration between the period before HD and at 48 hours in the control and the second week. Plasma phosphate concentration before HD not only depended on phosphate mass removal by HD, but also on other factors. We suggest that dialysate containing phosphate might prevent excessive phosphate removal from non-extracellular compartments during HD.

Dietary prevention of azoxymethane-induced colon carcinogenesis with rice-germ in F344 rats

The modifying effect of dietary administration of defatted rice-germ and gamma-aminobutyric acid (GABA)-enriched defatted rice-germ on azoxymethane (AOM)-induced colon carcinogenesis was investigated in two experiments with male F344 rats. In the first experiment (the pilot study), the effects of the defatted rice-germ, the GABA-enriched defatted rice-germ and rice-germ on AOM-induced (15 mg/kg body wt once a week for 3 weeks) formation of aberrant crypt foci (ACF) were examined. The latter two preparations (2.5% in the diet) significantly inhibited ACF formation (P < 0.005). In the second experiment, a long-term study of the effects of rice-germ was done. One group was treated with AOM alone, four groups received the carcinogen and were fed the diets containing 2.5% rice-germ or 2.5% GABA-enriched defatted rice-germ for 5 (initiation phase) or 30 weeks (post-initiation phase), two groups were treated with rice-germ or GABA-enriched defatted rice-germ alone and one group was kept on the basal diet. At the termination of the study, dietary exposure to rice-germ during the initiation phase significantly reduced the incidence of colonic adenocarcinoma (71 versus 29%, P < 0.01). GABA-enriched defatted rice-germ or rice-germ during the post-initiation phase also decreased the frequency of colonic adenocarcinoma (71 versus 20%, GABA-enriched defatted rice-germ feeding, P < 0.01; 27%, rice-germ feeding, P < 0.01). These data suggest that constituents of rice-germ are possible dietary preventatives for human colon cancers.

Stimulatory and inhibitory properties of aminoglycoside antibiotics at N-methyl-D-aspartate receptors

The effects of aminoglycoside antibiotics on N-methyl-D-aspartate (NMDA) receptors were studied using voltage-clamp recording of recombinant NMDA receptors expressed in Xenopus oocytes. A number of aminoglycosides were found to potentiate macroscopic currents at heteromeric NR1A/NR2B receptors, but not at NR1A/NR2A, NR1A/NR2C, NR1A/NR2D, or NR1B/NR2B receptors. The degree of potentiation had a rank order neomycin B > paromomycin > gentamicin C > geneticin > kanamycin A > streptomycin. Potentiation was not seen with kasugamycin and spectinomycin. The degree of stimulation paralleled the number of the amino groups in the aminoglycosides. The stimulatory effects of aminoglycosides were more pronounced at subsaturating concentrations of glycine and at acidic pH, similar to the stimulatory effects of spermine. We measured the effects of aminoglycosides at mutant NMDA receptors to determine which amino acid residues in NMDA receptor subunits are involved in stimulation. Mutations that reduced or abolished spermine stimulation also reduced stimulation by aminoglycosides. Several aminoglycosides produced a weak voltage-dependent block of NMDA receptors, but the degree of inhibition did not appear to correlate with the number of amino groups in the molecule. The results suggest that aminoglycosides having more than three amino groups have stimulatory effects that are mediated through the spermine-binding site on NMDA receptors.

[A case of internal hernia through a defect in the falciform ligament treated with laparoscopic surgery]

A 22-year-old male was admitted to our hospital with abrupt onset of upper abdominal pain. Abdominal US and CT revealed dilatation of the small intestine between the abdominal wall and a lateral segment of the liver. After a diagnosis of an internal hernia through a defect in the falciform ligament, emergency surgery was performed. Laparoscopic investigation showed incarceration of the small intestine in a defect of the falciform ligament. After releasing an incarceration, the hernia orifice was opened to prevent relapse. He was discharged on the 4th postoperative day. Internal hernia through a defect in the falciform ligament is extremely rare, with six reported cases including our own in Japan. Characteristic images of abdominal US and CT enable preoperative diagnosis of this condition. Surgery should be performed at an early stage after onset. In patients with no prior history of surgery, laparoscopic techniques may be useful.

The MAPK kinase Pek1 acts as a phosphorylation-dependent molecular switch

The mitogen-activated protein kinase (MAPK) pathway is a highly conserved eukaryotic signalling cascade that converts extracellular signals into various outputs, such as cell growth and differentiation. MAPK is phosphorylated and activated by a specific MAPK kinase (MAPKK): MAPKK is therefore considered to be an activating regulator of MAPK. Pmk1 is a MAPK that regulates cell integrity and which, with calcineurin phosphatase, antagonizes chloride homeostasis in fission yeast. We have now identified Pek1, a MAPKK for Pmk1 MAPK. We show here that Pek1, in its unphosphorylated form, acts as a potent negative regulator of Pmk1 MAPK signalling. Mkh1, an upstream MAPKK kinase (MAPKKK), converts Pek1 from being an inhibitor to an activator. Our results indicate that Pek1 has a dual stimulatory and inhibitory function which depends on its phosphorylation state. This switch-like mechanism could contribute to the all-or-none physiological response mediated by the MAPK signalling pathway.