Using Policy Briefs to Communicate Dental Research Findings to Policymakers

OBJECTIVES

New scientific knowledge is not always available to decision makers. Policy briefs are a way that dental researchers can communicate research findings to policymakers. This study compares usefulness of 2 types of policy briefs about sugar-sweetened beverage (SSB) intake and tooth decay.

METHODS

We developed 2 policy brief types (data focused and narrative focused) and emailed a randomly assigned policy brief to 825 policymakers and staff from 3 levels of government (city, county, and state) in Washington State. Participants completed a 22-item online questionnaire. There were 4 study outcomes: whether the brief was understandable, whether the brief was credible, likelihood of use, and likelihood to be shared (each measured on a 5-point Likert-like scale). The t test was used to evaluate whether outcomes differed by policy brief type and government level (α = 0.05).

RESULTS

There were 108 respondents (adjusted response rate 14.6%). About 41.6% of participants were in city government, 26.9% were in county government, and 29.6% were in state government. Participants reported that both data- and narrative-focused briefs were understandable (mean rating [MR] and standard deviation [SD]: 4.15 ± 0.68 and 4.09 ± 0.81, respectively; P = 0.65) and credible (MR and SD: 4.13 ± 0.70 and 4.09 ± 0.70, respectively; P = 0.74), but they were not likely to use (MR and SD: 2.71 ± 1.15 and 2.55 ± 1.28, respectively; P = 0.51) or share it (MR and SD: 2.62 ± 1.04 and 2.66 ± 1.30, respectively; P = 0.87). The likelihood of sharing briefs differed significantly by level of government (P = 0.017). Participants at the state level were more likely to share information from the briefs (mean rating and SD: 3.10 ± 0.80) than city- and county-level participants (MR and SD: 2.62 ± 1.27, and 2.24 ± 1.21, respectively).

CONCLUSION

Both data- and narrative-focused policy briefs may be a useful way to communicate dental research findings to policymakers, but additional steps are needed to ensure that briefs are used and shared.

KNOWLEDGE TRANSFER STATEMENT

Researchers should disseminate their research findings to maximize scientific impact. Our study findings indicate that policy briefs may be a useful way to communicate dental research findings to policymakers, but additional research is needed on the best ways to disseminate findings.

Catalase-deficient mice induce aging faster through lysosomal dysfunction

BACKGROUND

Lysosomes are a central hub for cellular metabolism and are involved in the regulation of cell homeostasis through the degradation or recycling of unwanted or dysfunctional organelles through the autophagy pathway. Catalase, a peroxisomal enzyme, plays an important role in cellular antioxidant defense by decomposing hydrogen peroxide into water and oxygen. In accordance with pleiotropic significance, both impaired lysosomes and catalase have been linked to many age-related pathologies with a decline in lifespan. Aging is characterized by progressive accumulation of macromolecular damage and the production of high levels of reactive oxygen species. Although lysosomes degrade the most long-lived proteins and organelles via the autophagic pathway, the role of lysosomes and their effect on catalase during aging is not known. The present study investigated the role of catalase and lysosomal function in catalase-knockout (KO) mice.

METHODS

We performed experiments on WT and catalase KO younger (9 weeks) and mature adult (53 weeks) male mice and Mouse embryonic fibroblasts isolated from WT and KO mice from E13.5 embryos as in vivo and in ex-vivo respectively. Mouse phenotyping studies were performed with controls, and a minimum of two independent experiments were performed with more than five mice in each group.

RESULTS

We found that at the age of 53 weeks (mature adult), catalase-KO mice exhibited an aging phenotype faster than wild-type (WT) mice. We also found that mature adult catalase-KO mice induced leaky lysosome by progressive accumulation of lysosomal content, such as cathespin D, into the cytosol. Leaky lysosomes inhibited autophagosome formation and triggered impaired autophagy. The dysregulation of autophagy triggered mTORC1 (mechanistic target of rapamycin complex 1) activation. However, the antioxidant N-acetyl-L-cysteine and mTORC1 inhibitor rapamycin rescued leaky lysosomes and aging phenotypes in catalase-deficient mature adult mice.

CONCLUSIONS

This study unveils the new role of catalase and its role in lysosomal function during aging. Video abstract.

Catalase deficiency facilitates the shuttling of free fatty acid to brown adipose tissue through lipolysis mediated by ROS during sustained fasting

Background

Fatty acids (FA) derived from adipose tissue and liver serve as the main fuel in thermogenesis of brown adipose tissue (BAT). Catalase, a peroxisomal enzyme, plays an important role in maintaining intracellular redox homeostasis by decomposing hydrogen peroxide to either water or oxygen that oxidize and provide fuel for cellular metabolism. Although the antioxidant enzymatic activity of catalase is well known, its role in the metabolism and maintenance of energy homeostasis has not yet been revealed. The present study investigated the role of catalase in lipid metabolism and thermogenesis during nutrient deprivation in catalase-knockout (KO) mice.

Results

We found that hepatic triglyceride accumulation in KO mice decreased during sustained fasting due to lipolysis through reactive oxygen species (ROS) generation in adipocytes. Furthermore, the free FA released from lipolysis were shuttled to BAT through the activation of CD36 and catabolized by lipoprotein lipase in KO mice during sustained fasting. Although the exact mechanism for the activation of the FA receptor enzyme, CD36 in BAT is still unclear, we found that ROS generation in adipocytes mediated the shuttling of FA to BAT.

Conclusions

Taken together, our findings uncover the novel role of catalase in lipid metabolism and thermogenesis in BAT, which may be useful in understanding metabolic dysfunction.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13578-021-00710-5.

Catalase deficiency induces reactive oxygen species mediated pexophagy and cell death in the liver during prolonged fasting

Peroxisomes are dynamic organelles that participate in a diverse array of cellular processes, including β-oxidation, which produces a considerable amount of reactive oxygen species (ROS). Although we showed that catalase depletion induces ROS-mediated pexophagy in cells, the effect of catalase deficiency during conditions that favor ROS generation remains elusive in mice. In this study, we reported that prolonged fasting in catalase-knockout (KO) mice drastically increased ROS production, which induced liver-specific pexophagy, an autophagic degradation of peroxisomes. In addition, increased ROS generation induced the production of pro-inflammatory cytokines in the liver tissues of catalase-KO mice. Furthermore, there was a significant increase in the levels of aspartate transaminase and alanine transaminase as well as apparent cell death in the liver of catalase-KO mice during prolonged fasting. However, an intra-peritoneal injection of the antioxidant N-acetyl-l-cysteine (NAC) and autophagy inhibitor chloroquine inhibited the inflammatory response, liver damage, and pexophagy in the liver of catalase-KO mice during prolonged fasting. Consistently, genetic ablation of autophagy, Atg5 led to suppression of pexophagy during catalase inhibition by 3-aminotriazole (3AT). Moreover, treatment with chloroquine also ameliorated the inflammatory response and cell death in embryonic fibroblast cells from catalase-KO mice. Taken together, our data suggest that ROS-mediated liver-specific pexophagy observed during prolonged fasting in catalase-KO mice may be responsible for the process associated with hepatic cell death.

TMEM135 regulates primary ciliogenesis through modulation of intracellular cholesterol distribution

Recent evidence has linked the lysosomal cholesterol accumulation in Niemann–Pick type C1 with anomalies associated with primary ciliogenesis. Here, we report that perturbed intracellular cholesterol distribution imposed by lysosomal cholesterol accumulation during TMEM135 depletion is closely associated with impaired ciliogenesis. TMEM135 depletion does not affect the formation of the basal body and the ciliary transition zone. TMEM135 depletion severely blunts Rab8 trafficking to the centrioles without affecting the centriolar localization of Rab11 and Rabin8, the upstream regulators of Rab8 activation. Although TMEM135 depletion prevents enhanced IFT20 localization at the centrioles, ciliary vesicle formation is not affected. Furthermore, enhanced IFT20 localization at the centrioles is dependent on Rab8 activation. Supplementation of cholesterol in complex with cyclodextrin rescues Rab8 trafficking to the centrioles and Rab8 activation, thereby recovering primary ciliogenesis in TMEM135‐depleted cells. Taken together, our data suggest that TMEM135 depletion prevents ciliary vesicle elongation, a characteristic of impaired Rab8 function. Our study thus reveals a previously uncharacterized effect of erroneous intracellular cholesterol distribution on impairing Rab8 function and primary ciliogenesis.

Slc25a17 acts as a peroxisomal coenzyme A transporter and regulates multiorgan development in zebrafish

Slc25a17 is known as a peroxisomal solute carrier, but the in vivo role of the protein has not been demonstrated. We found that the zebrafish genome contains two slc25a17 genes that function redundantly, but additively. Notably, peroxisome function in slc25a17 knockdown embryos is severely compromised, resulting in an altered lipid composition. Along the defects found in peroxisome-associated phenotypic presentations, we highlighted that development of the swim bladder is also highly dependent on Slc25a17 function. As Slc25a17 showed substrate specificity towards coenzyme A (CoA), injecting CoA, but not NAD⁺ , rescued the defective swim bladder induced by slc25a17 knockdown. These results indicated that Slc25a17 acts as a CoA transporter, involved in the maintenance of functional peroxisomes that are essential for the development of multiple organs during zebrafish embryogenesis. Given high homology in protein sequences, the role of zebrafish Slc25a17 may also be applicable to the mammalian system.

Clinical factors predicting persistent carriage of Klebsiella pneumoniae carbapenemase-producing carbapenem-resistant Enterobacteriaceae among patients with known carriage

BACKGROUND

Information on the natural duration of carbapenem-resistant Enterobacteriaceae (CRE) carriage and factors associated with persistence of carriage is limited.

AIM

To evaluate the clinical variables associated with persistent carriage of Klebsiella pneumoniae carbapenemase (KPC)-producing CRE.

METHODS

Data for patients admitted between June 2015 and December 2016 who were identified as KPC-producing CRE carriers by either rectal swabs or clinical cultures were reviewed retrospectively. Patients with follow-up culture data for three months after initial acquisition were included. Regression models were used to evaluate the clinical variables associated with persistence of carriage.

FINDINGS

Of the 100 eligible patients, 50 patients (50%) experienced spontaneous decolonization within three months. Among the 50 patients (50%) who remained culture positive after three months, 26 patients carried KPC-producing CRE after six months. Multi-variable analysis revealed that re-admission [adjusted odds ratio (aOR) 9.96; 95% confidence interval (CI) 1.13-87.98; P=0.039], duration of hospitalization (aOR 1.03; 95% CI 1.01-1.05; P=0.003), positive clinical culture (aOR 6.26; 95% CI 1.28-30.54; P=0.023) and carbapenem use (OR 9.15; 95% CI 1.85-45.27; P=0.007) were predictive for persistent carriage after six months.

CONCLUSION

The results suggest that patients with KPC-producing CRE in clinical specimens who are using carbapenem, particularly those with multiple and prolonged hospitalizations, are more likely to remain carriers after six months of initial acquisition. This information is useful for coordinating strategies for pre-emptive isolation by predicting the CRE carriage status appropriately, and ensuring active surveillance through risk factor stratification.

Protective roles of fenofibrate against cisplatin-induced ototoxicity by the rescue of peroxisomal and mitochondrial dysfunction

Cisplatin is an alkylating agent that interferes with DNA replication and kills proliferating carcinogenic cells. Several studies have been conducted to attenuate the side effects of cisplatin; one such side effect in cancer patients undergoing cisplatin chemotherapy is ototoxicity. However, owing to a lack of understanding of the precise mechanism underlying cisplatin-induced side effects, management of cisplatin-induced ototoxicity remains unsolved. We investigated the protective effects of fenofibrate, a PPAR-α activator, on cisplatin-induced ototoxicity. Fenofibrate prevented cisplatin-induced loss of hair cells and improved cell viability; moreover, fenofibrate significantly attenuated the threshold of auditory brainstem responses (ABR) in cisplatin-injected mice. Fenofibrate significantly increased PPAR-α, PPAR-γ, and PGC-1α expression, which consequently resulted in increased number and functional enzyme levels of peroxisomes and mitochondria, and markedly decreased phospho-p53 (S15), activated caspase-3, cleaved-PARP, and NF-κB p65 nuclear translocation, which reduced NADPH oxidase isoform (NOX3 and NOX4) expression, thereby decreasing reactive oxygen species (ROS) production in cisplatin-treated tissues ex vivo. Taken together, these results indicate that fenofibrate rescues cisplatin-induced ototoxicity by maintaining peroxisome and mitochondria number and function, reducing inflammation, and decreasing ROS levels. Our findings suggest that fenofibrate administration might serve as an effective therapeutic agent against cisplatin-induced ototoxicity.

Ciliogenesis is reciprocally regulated by PPARA and NR1H4/FXR through controlling autophagy in vitro and in vivo

The primary cilia are evolutionarily conserved microtubule-based cellular organelles that perceive metabolic status and thus link the sensory system to cellular signaling pathways. Therefore, ciliogenesis is thought to be tightly linked to autophagy, which is also regulated by nutrient-sensing transcription factors, such as PPARA (peroxisome proliferator activated receptor alpha) and NR1H4/FXR (nuclear receptor subfamily 1, group H, member 4). However, the relationship between these factors and ciliogenesis has not been clearly demonstrated. Here, we present direct evidence for the involvement of macroautophagic/autophagic regulators in controlling ciliogenesis. We showed that activation of PPARA facilitated ciliogenesis independently of cellular nutritional states. Importantly, PPARA-induced ciliogenesis was mediated by controlling autophagy, since either pharmacological or genetic inactivation of autophagy significantly repressed ciliogenesis. Moreover, we showed that pharmacological activator of autophagy, rapamycin, recovered repressed ciliogenesis in ppara^-/- cells. Conversely, activation of NR1H4 repressed cilia formation, while knockdown of NR1H4 enhanced ciliogenesis by inducing autophagy. The reciprocal activities of PPARA and NR1H4 in regulating ciliogenesis were highlighted in a condition where de-repressed ciliogenesis by NR1H4 knockdown was further enhanced by PPARA activation. The in vivo roles of PPARA and NR1H4 in regulating ciliogenesis were examined in greater detail in ppara^-/- mice. In response to starvation, ciliogenesis was facilitated in wild-type mice via enhanced autophagy in kidney, while ppara^-/- mice displayed impaired autophagy and kidney damage resembling ciliopathy. Furthermore, an NR1H4 agonist exacerbated kidney damage associated with starvation in ppara^-/- mice. These findings indicate a previously unknown role for PPARA and NR1H4 in regulating the autophagy-ciliogenesis axis in vivo.

PEX5 regulates autophagy via the mTORC1-TFEB axis during starvation

Defects in the PEX5 gene impair the import of peroxisomal matrix proteins, leading to nonfunctional peroxisomes and other associated pathological defects such as Zellweger syndrome. Although PEX5 regulates autophagy process in a stress condition, the mechanisms controlling autophagy by PEX5 under nutrient deprivation are largely unknown. Herein, we show a novel function of PEX5 in the regulation of autophagy via Transcription Factor EB (TFEB). Under serum-starved conditions, when PEX5 is depleted, the mammalian target of rapamycin (mTORC1) inhibitor TSC2 is downregulated, which results in increased phosphorylation of the mTORC1 substrates, including 70S6K, S6K, and 4E-BP-1. mTORC1 activation further suppresses the nuclear localization of TFEB, as indicated by decreased mRNA levels of TFEB, LIPA, and LAMP1. Interestingly, peroxisomal mRNA and protein levels are also reduced by TFEB inactivation, indicating that TFEB might control peroxisome biogenesis at a transcriptional level. Conversely, pharmacological inhibition of mTOR resulting from PEX5 depletion during nutrient starvation activates TFEB by promoting nuclear localization of the protein. In addition, mTORC1 inhibition recovers the damaged-peroxisome biogenesis. These data suggest that PEX5 may be a critical regulator of lysosomal gene expression and autophagy through the mTOR-TFEB-autophagy axis under nutrient deprivation.

A protein essential for the formation of peroxisomes—cellular organelles that perform diverse metabolic functions—also regulates cellular ‘recycling centers’ that break biomolecules down into nutrients. Researchers led by Raekil Park at the Gwangju Institute of Science and Technology in South Korea have now linked this protein, known as PEX5, to the function of another critical cellular organelle. Lysosomes participate in a process called autophagy, in which non-essential or damaged cellular components and biomolecules are digested to generate nutrients in times of deprivation. Park’s team determined that in the absence of PEX5, starved cells lose the ability to effectively initiate autophagy. They also identified the molecular pathways affected by PEX5 deficiency. These findings indicate a strong functional link between the peroxisome and lysosome, and could aid the development of treatments for certain metabolic disorders.

Metastasectomy for recurrent or metastatic biliary tract cancers: A single center experience

PURPOSE

To assess efficacy or long-term result of metastasectomy for recurrent or metastatic biliary tract carcinoma (BTC), we conducted a retrospective review of the outcomes of metastasectomy for recurrent or metastatic BTCs, comprising intrahepatic cholangiocellular carcinoma (IHCCC), proximal and distal common bile duct cancer (pCBDC and dCBDC), gallbladder cancer (GBC), and ampulla of Vater cancer (AoVC).

PATIENTS AND METHODS

The clinicopathological features and outcomes of BTC patients who underwent surgical resection for the primary and metastatic disease at the Gachon University Gil Medical Centre from 2003 to 2013 were reviewed retrospectively.

RESULTS

We found 19 eligible patients. Primary sites were GBC (seven patients, 37%), IHCCC (five patients, 26%), dCBDC (three patients, 16%), pCBDC (two patients, 11%), and AoVC (two patients, 11%). Eight patients (42%) had synchronous metastasis whereas 11 (58%) had metachronous metastasis. The most common metastatic site was liver (nine patients, 47%), lymph node (nine patients, 47%), and peritoneum (three patients, 16%). Nine patients (47%) achieved R0 resection, whereas four (21%) and six (32%) patients had R1 and R2 resection, respectively. With a median follow-up period of 26.7 months, the estimated median overall survival (OS) was 18.2 months (95% confidence interval, 13.6-22.9 months). Lower Eastern Cooperative Oncology Group performance status (P = 0.023), metachronous metastasis (P = 0.04), absence of lymph node metastasis (P = 0.009), lower numbers of metastatic organs (P < 0.001), normal postoperative CA19-9 level (P = 0.034), and time from diagnosis to metastasectomy more than 1 year (P = 0.019) were identified as prognostic factors for a longer OS after metastasectomy.

CONCLUSIONS

For recurrent or metastatic BTCs, metastasectomy can be a viable option for selected patients.

Fenofibrate exerts protective effects against gentamicin-induced toxicity in cochlear hair cells by activating antioxidant enzymes

Fenofibrate, an activator of peroxisome proliferator-activated receptors (PPARs), has been shown to protect the kidneys and brain cells from oxidative stress; however, its role in preventing hearing loss has not been reported to date, at least to the best of our knowledge. In this study, we demonstrated the protective effects of fenofibrate against gentamicin (GM)-induced ototoxicity. We found that the auditory brainstem response threshold which was increased by GM was significantly reduced by pre-treatment with fenofibrate in rats. In cochlear explants, the disruption of hair cell layers by GM was also markedly attenuated by pre-treatment with fenofibrate. In addition, fenofibrate almost completely abolished GM-induced reactive oxygen species generation, which seemed to be mediated at least in part by the restoration of the expression of PPAR-α-dependent antioxidant enzymes, including catalase and superoxide dismutase (SOD)-1. Of note, fenofibrate markedly increased the expression of heme oxygenase-1 (HO-1) which was also induced to a certain degree by GM alone. The induced expression of HO-1 by fenofibrate appeared to be essential for mediating the protective effects of fenofibrate, as the inhibition of HO-1 activity significantly diminished the protective effects of fenofibrate against the GM-mediated death of sensory hair cells in cochlea explant culture, as well as in zebrafish neuromasts. These results suggest that fenofibrate protects sensory hair cells from GM-induced toxicity by upregulating PPAR-α-dependent antioxidant enzymes, including HO-1. Our results provide insight into the preventive therapy for hearing loss caused by aminoglycoside antibiotics.

The inhibitory effect of beta-lapachone on RANKL-induced osteoclastogenesis

β-lapachone (β-L) is a substrate of reduced nicotinamide adenine dinucleotide (NADH): quinone oxidoreductase 1 (NQO1). NQO1 reduces quinones to hydroquinones using NADH as an electron donor and consequently increases the intracellular NAD+/NADH ratio. The activation of NQO1 by β-L has beneficial effects on several metabolic syndromes, such as obesity, hypertension, and renal injury. However, the effect of β-L on bone metabolism remains unclear. Here, we show that β-L might be a potent inhibitor of receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclastogenesis. β-L inhibited osteoclast formation in a dose-dependent manner and also reduced the expression of osteoclast differentiation marker genes, such as tartrate-resistant acid phosphatase (Acp5 or TRAP), cathepsin K (CtsK), the d2 isoform of vacuolar ATPase V0 domain (Atp6v0d2), osteoclast-associated receptor (Oscar), and dendritic cell-specific transmembrane protein (Dc-stamp). β-L treatment of RANKL-induced osteoclastogenesis significantly increased the cellular NAD+/NADH ratio and resulted in the activation of 5' AMP-activated protein kinase (AMPK), a negative regulator of osteoclast differentiation. In addition, β-L treatment led to significant suppression of the expression of peroxisome proliferator-activated receptor gamma (PPARγ) and peroxisome proliferator-activated receptor gamma coactivator 1β (PGC1β), which can stimulate osteoclastogenesis. β-L treatment downregulated c-Fos and nuclear factor of activated T-cells 1 (NFATc1), which are master transcription factors for osteoclastogenesis. Taken together, the results demonstrated that β-L inhibits RANKL-induced osteoclastogenesis and could be considered a potent inhibitor of RANKL-mediated bone diseases, such as postmenopausal osteoporosis, rheumatoid arthritis, and periodontitis.

The fatty acid chain elongase, Elovl1, is required for kidney and swim bladder development during zebrafish embryogenesis

Very long chain fatty acids are required for sphingolipid synthesis, lipid homeostasis, myelin formation, epidermal permeability, and retinal function. Seven different enzymes are known to be involved in the elongation cycle of fatty acids, with different chain-length specificities. Elovl1 is one of those enzymes whose function has been linked mainly to the synthesis of sphingolipids and the epidermal barrier. However, the role of Elovl1 in organogenesis is not clear. In zebrafish, 2 Elovl1 genes, elovl1a and elovl1b, are highly expressed in the swim bladder, and elovl1b is also expressed in the kidney. We found that both elovl1 knockdown embryos contain increased levels of long chain fatty acids from carbon number 14 to 20 as compared to control embryos. Oil-Red-O staining shows that yolk lipid consumption is greatly reduced, whereas lipid droplets accumulate within the swim bladder. Notably, knockdown of either elovl1a or elovl1b affects the expression of genes involved in swim bladder development and impairs inflation of the swim bladder. Consistent with its expression in the pronephros, knockdown of elovl1b alone affects the expression of genes required for kidney development and reduces renal clearance. Our findings strongly suggest that both elovl1 genes are a key determinant of swim bladder and kidney development in zebrafish, which may be comparatively applicable to lung and kidney development in humans.

Cartilage development requires the function of Estrogen-related receptor alpha that directly regulates sox9 expression in zebrafish

Estrogen-related receptor alpha (ESRRa) regulates a number of cellular processes including development of bone and muscles. However, direct evidence regarding its involvement in cartilage development remains elusive. In this report, we establish an in vivo role of Esrra in cartilage development during embryogenesis in zebrafish. Gene expression analysis indicates that esrra is expressed in developing pharyngeal arches where genes necessary for cartilage development are also expressed. Loss of function analysis shows that knockdown of esrra impairs expression of genes including sox9, col2a1, sox5, sox6, runx2 and col10a1 thus induces abnormally formed cartilage in pharyngeal arches. Importantly, we identify putative ESRRa binding elements in upstream regions of sox9 to which ESRRa can directly bind, indicating that Esrra may directly regulate sox9 expression. Accordingly, ectopic expression of sox9 rescues defective formation of cartilage induced by the knockdown of esrra. Taken together, our results indicate for the first time that ESRRa is essential for cartilage development by regulating sox9 expression during vertebrate development.

RAS status in Korean patients with stage III and IV colorectal cancer

BACKGROUND

KRAS mutations are common and clearly contribute to malignant progression. The frequency of NRAS mutations and their relationship to clinical, pathologic, and molecular features remains unclear.

METHODS

We evaluated 130 colorectal tumors for mutations in KRAS and NRAS gene. We tested for mutations in codons 61 and 146 of KRAS and codons 12, 13, 59, 61 and 146 of NRAS. Mutation status was determined by targeted dideoxy sequencing.

RESULTS

Among the analyzed primary tumors, 36.2% had KRAS mutation. Of the 83 KRAS codon 12 and 13 wild-type patients, 7.2% had KRAS codon 61, 146 or NRAS. 40.7% harbored any RAS mutation.

CONCLUSION

The frequency of other RAS (NRAS and KRAS exon 3, 4) activating mutations in colorectal cancers is relatively low in Korean colorectal cancer patients.

Bucillamine prevents cisplatin-induced ototoxicity through induction of glutathione and antioxidant genes

Bucillamine is used for the treatment of rheumatoid arthritis. This study investigated the protective effects of bucillamine against cisplatin-induced damage in auditory cells, the organ of Corti from postnatal rats (P2) and adult Balb/C mice. Cisplatin increases the catalytic activity of caspase-3 and caspase-8 proteases and the production of free radicals, which were significantly suppressed by pretreatment with bucillamine. Bucillamine induces the intranuclear translocation of Nrf2 and thereby increases the expression of γ-glutamylcysteine synthetase (γ-GCS) and glutathione synthetase (GSS), which further induces intracellular antioxidant glutathione (GSH), heme oxygenase 1 (HO-1) and superoxide dismutase 2 (SOD2). However, knockdown studies of HO-1 and SOD2 suggest that the protective effect of bucillamine against cisplatin is independent of the enzymatic activity of HO-1 and SOD. Furthermore, pretreatment with bucillamine protects sensory hair cells on organ of Corti explants from cisplatin-induced cytotoxicity concomitantly with inhibition of caspase-3 activation. The auditory-brainstem-evoked response of cisplatin-injected mice shows marked increases in hearing threshold shifts, which was markedly suppressed by pretreatment with bucillamine in vivo. Taken together, bucillamine protects sensory hair cells from cisplatin through a scavenging effect on itself, as well as the induction of intracellular GSH.

Oncologic outcomes of laparoscopic nephroureterectomy for pT3 upper urinary tract urothelial carcinoma

AIM

We present the oncologic outcomes of laparoscopic nephroureterectomy management of pT3 upper urinary tract urothelial carcinoma.

METHODS

Between October 2003 and January 2011, 50 patients with pT3 upper urinary tract urothelial carcinoma which had pathologically confirmed underwent laparoscopic nephroureterectomy at our institution. Demographic data, perioperative results, pathological findings and oncologic outcomes were reviewed and analyzed retrospectively.

RESULTS

There were 36 patients (72%) of high grade lesion and 14 patients (28%) of low grade lesion. Lymphovascular invasion was observed in 16 patients (32%) and the surgical margin was positive in one patient. N stage was pN0 in 16 (32%), pN1 in 3 (6%), pN2 in 1 (2%) and pN3 in 1 (2%). The 5-year overall survival rate was 52.6% and the 5-year cancer-specific survival rate was 65.3%. Overall recurrence developed in 23 patients. There were 10 patients (20%) of urothelial recurrence which were all occurred in the bladder at the mean period of 13.6 months, and 7 patients of them were invasive bladder cancer. There were 16 patients (32%) of non-urothelial recurrence developed at the mean period of 9.69 months. On multivariate analyses lymphadenopathy and lymph node involvement of cancer (N+) were identified as independent predictive factors for the cancer-specific survival, and concomitant bladder tumor, grade and lymphovascular invasion were identified as independent predictive factors for the overall recurrence free survival.

CONCLUSION

Laparoscopic nephroureterectomy in patients with high stage upper urinary tract urothelial carcinoma appear comparable to those of open surgery in the regard of oncologic outcomes.

Activation of β-catenin by inhibitors of glycogen synthase kinase-3 ameliorates cisplatin-induced cytotoxicity and pro-inflammatory cytokine expression in HEI-OC1 cells

Cisplatin is used in the treatment of a wide variety of solid tumors, but its use is limited by its serious adverse effects, including ototoxicity. Glycogen synthase kinase-3 (GSK-3) is a ubiquitously expressed serine/threonine kinase that regulates a variety of cellular functions by phosphorylating its substrates. However, the otoprotective effect of GSK-3 inhibitors is poorly understood. Here, we investigated whether GSK-3 is involved in cisplatin-induced ototoxicity in HEI-OC1 cells and organs of Corti (OCs). GSK-3 inhibitors suppressed cisplatin-induced apoptosis determined by decreased p53 activity, and also decreased expression of PARP and p53 target genes such as p21 and PUMA. The effect of GSK-3 inhibitors was mediated by markedly increased nuclear β-catenin that in turn blocked nuclear translocation of NF-κB. siRNA-mediated β-catenin knockdown markedly increased the expression of NF-κB target genes, such as TNF-α and IL-6. Our data suggest that the GSK-3/β-catenin pathway may play a central role in cisplatin-mediated cytotoxicity in HEI-OC1 cells and hair cells of OCs in vitro.

Developmental roles of D-bifunctional protein-A zebrafish model of peroxisome dysfunction

The peroxisome is an intracellular organelle that responds dynamically to environmental changes. Various model organisms have been used to study the roles of peroxisomal proteins in maintaining cellular homeostasis. By taking advantage of the zebrafish model whose early stage of embryogenesis is dependent on yolk components, we examined the developmental roles of the D-bifunctional protein (Dbp), an essential enzyme in the peroxisomal β-oxidation. The knockdown of dbp in zebrafish phenocopied clinical manifestations of its deficiency in human, including defective craniofacial morphogenesis, growth retardation, and abnormal neuronal development. Overexpression of murine Dbp rescued the morphological phenotypes induced by dbp knockdown, indicative of conserved roles of Dbp during zebrafish and mammalian development. Knockdown of dbp impaired normal development of blood, blood vessels, and most strikingly, endoderm-derived organs including the liver and pancreas - a phenotype not reported elsewhere in connection with peroxisome dysfunction. Taken together, our results demonstrate for the first time that zebrafish might be a useful model animal to study the role of peroxisomes during vertebrate development.

Sufficient production of geranylgeraniol is required to maintain endotoxin tolerance in macrophages

Endotoxin tolerance allows macrophages to produce large quantities of proinflammatory cytokines immediately after their contact with lipopolysaccharides (LPSs), but prevents their further production after repeated exposure to LPSs. While this response is known to prevent overproduction of proinflammatory cytokines, the mechanism through which endotoxin tolerance is established has not been identified. In the current study, we demonstrate that sufficient production of geranylgeraniol (GGOH) in macrophages is required to maintain endotoxin tolerance. We show that increased synthesis of 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMGCR) protein following LPS treatment is required to produce enough GGOH to inhibit expression of Malt1, a protein known to stimulate expression of proinflammatory cytokines, in macrophages repeatedly exposed to LPSs. Depletion of GGOH caused by inhibition of HMGCR led to increased Malt1 expression in macrophages subjected to repeated exposure to LPSs. Consequently, endotoxin tolerance was impaired, and production of interleukin 1-β and other proinflammatory cytokines was markedly elevated in these cells. These results suggest that insufficient production of GGOH in macrophages may cause autoinflammatory diseases.

Establishment of a bone-specific col10a1:GFP transgenic zebrafish

During skeletal development, both osteogenic and chondrogenic programs are initiated from multipotent mesenchymal cells, requiring a number of signaling molecules, transcription factors, and downstream effectors to orchestrate the sophisticated process. Col10a1, an important downstream effector gene, has been identified as a marker for maturing chondrocytes in higher vertebrates, such as mammals and birds. In zebrafish, this gene has been shown to be expressed in both osteoblasts and chondrocytes, but no study has reported its role in osteoblast development. To initially delineate the osteogenic program from chondrogenic lineage development, we used the zebrafish col10a1 promoter to establish a transgenic zebrafish expressing a GFP reporter specifically in osteoblast-specific bone structures that do not involve cartilaginous programs. A construct harboring a -2.2-kb promoter region was found to be sufficient to drive the reporter gene in osteoblast-specific bone structures within the endogenous col10a1 expression domain, confirming that separable cis-acting elements exist for distinct cell type-specific expression of col10a1 during zebrafish skeletal development. The -2.2-kb col10a1:GFP transgenic zebrafish marking only bone structures derived from osteoblasts will undoubtedly be an invaluable tool for identifying and characterizing molecular events driving osteoblast development in zebrafish, which may further provide a differential mechanism where col10a1 is involved in the development of chondrocytes undergoing maturation in other vertebrate systems.

UAS domain of Ubxd8 and FAF1 polymerizes upon interaction with long-chain unsaturated fatty acids

Ubxd8, a multidomain protein sensor for long-chain unsaturated fatty acids (FAs), plays a crucial role to maintain cellular homeostasis of FAs. Ubxd8 polymerizes upon interaction with long-chain unsaturated FAs, but the molecular mechanism involved in this polymerization remains unclear. Here we report that the UAS domain of Ubxd8 mediates this polymerization. We show that a positively charged surface area in the domain is required for the reaction. Mutations changing the positively charged residues in this area to glutamates prevented long-chain unsaturated FAs from inducing oligomerization of Ubxd8. Consequently, the mutant protein no longer responded to regulation by long-chain unsaturated FAs in cultured cells. Long-chain unsaturated FAs also induced polymerization of Fas-associated factor 1 (FAF1), the only other mammalian protein that contains a UAS domain homologous to that of Ubxd8. These results provide further insights into protein-FA interactions by identifying the UAS domain as a motif interacting with long-chain unsaturated FAs.

Regulated endoplasmic reticulum-associated degradation of a polytopic protein: p97 recruits proteasomes to Insig-1 before extraction from membranes

Polytopic membrane proteins subjected to endoplasmic reticulum (ER)-associated degradation are extracted from membranes and targeted to proteasomes for destruction. The extraction mechanism is poorly understood. One polytopic ER protein subjected to ER-associated degradation is Insig-1, a negative regulator of cholesterol synthesis. Insig-1 is rapidly degraded by proteasomes when cells are depleted of cholesterol, and its degradation is inhibited when sterols accumulate in cells. Insig-2, a functional homologue of Insig-1, is degraded slowly, and its degradation is not regulated by sterols. Here, we report that a single amino acid substitution in Insig-2, Insig-2(L210A), causes Insig-2 to be degraded in an accelerated and sterol-regulated manner similar to Insig-1. In seeking an explanation for the accelerated degradation, we found that proteasomes bind to wild type Insig-1 and mutant Insig-2(L210A) but not to wild type Insig-2, whereas the proteins are still embedded in cell membranes. This binding depends on at least two factors, ubiquitination of Insig and association with the ATPase p97/VCP complex. These data suggest that p97 recruits proteasomes to polytopic ER proteins even before they are extracted from membranes.

Brain activation in multiple sclerosis: a BOLD fMRI study of the effects of fatiguing hand exercise

Background

Multiple sclerosis (MS) patients experience fatigue as a chronic symptom that decreases quality of life. Commonly, fatigue in MS patients is manifested as decreased motor function during or after physical activity and is associated with changes in brain metabolism.

Objective

To determine brain activation patterns in MS patients and healthy controls during a simple motor task before and after fatiguing hand-grip exercise.

Methods

Functional magnetic resonance imaging (fMRI) scans were conducted on 10 MS patients and 13 healthy controls during 4-finger flexion and extension in rested and fatigued states.

Results

Before the fatigue protocol, MS patients had greater activation in the contralateral primary motor cortex, insula, and cingulate gyrus than controls. Following fatiguing exercise, controls showed increased activation of precentral gyrus and insula while patients did not show any activation increases and actually decreased activity to the insula.

Conclusion

Results indicate that before fatiguing exercise, MS patients marshaled more brain activation compared to controls, which may represent functionally adaptive changes in response to demyelination. This increased activation may suggest that patients require more effort to perform even simple motor tasks, possibly because peripheral or central signals for fatigue are chronically enhanced. When fatigued further by muscle contraction, brain activation cannot be further increased.

Unsaturated fatty acids inhibit proteasomal degradation of Insig-1 at a postubiquitination step

Proteasomes mediate the regulated degradation of Insig-1, a membrane protein of the endoplasmic reticulum (ER) that plays a crucial role in lipid metabolism. We showed previously that sterols inhibit this degradation by blocking ubiquitination of Insig-1. Here we show that unsaturated fatty acids stabilize Insig-1 without affecting its ubiquitination. Instead unsaturated fatty acids inhibit extraction of ubiquitinated Insig-1 from membranes, a process known to be mediated by valosin-containing protein and necessary for ER-associated degradation. Valosin-containing protein is recruited to Insig-1 through the action of another protein, Ubxd8. Unsaturated fatty acids block the binding between Ubxd8 and Insig-1, thereby abrogating the membrane extraction of Insig-1. Unsaturated fatty acid-mediated stabilization of Insig-1 enhances the ability of sterols to inhibit proteolytic activation of SREBP-1, which activates transcription of genes involved in fatty acid synthesis. The current study provides a molecular mechanism for regulation of proteasome-mediated ER protein degradation at a postubiquitination step.

Prevalence of non-tuberculous mycobacteria in a hospital environment

In recent years, non-tuberculous mycobacteria (NTM) have emerged as an important cause of opportunistic nosocomial infections but there is little known about the isolation and identification of NTM in Korea. The aim of this study was to assess the prevalence of NTM in the hospital environment and identify the species. A total of 150 samples were collected from different parts of the hospital. NTM were isolated and identified by restriction fragment length polymorphism analysis of the gene encoding rpoB and partial sequencing analysis of hsp65 and rpoB. In this study, 60 strains of NTM were isolated from 50 of the 150 samples. Half of the tap water samples (50 of 100) were positive for mycobacteria. An estimated 73.3% of the isolates were saprophytic, 21.7% were potentially pathogenic and 5% were unidentified. The presence of NTM in hospital tap water is not uncommon. Such water isolates might cause true nosocomial infection in immunocompromised patients, in addition to the risk of false-positive culture results.

Sterol-regulated degradation of Insig-1 mediated by the membrane-bound ubiquitin ligase gp78

Insig-1 and Insig-2, closely related endoplasmic reticulum membrane proteins, mediate transcriptional and post-transcriptional mechanisms that assure cholesterol homeostasis through their sterol-induced binding to Scap (SREBP cleavage-activating protein) and 3-hydroxy-3-methylglutaryl coenzyme A reductase. Recent studies show that Insig-1 (but not Insig-2) is ubiquitinated and rapidly degraded when cells are depleted of sterols. Conversely, ubiquitination of Insig-1 is blocked, and the protein is stabilized when intracellular sterols accumulate. Here, we report that the ubiquitin ligase gp78, which binds with much higher affinity to Insig-1 than Insig-2, is required for ubiquitination and degradation of Insig-1 in sterol-depleted cells. Sterols prevent Insig-1 ubiquitination and degradation by displacing gp78 from Insig-1, an event that results from sterol-induced binding of Scap to Insig-1. In addition to providing a mechanism for sterol-regulated degradation of Insig-1, these results help to explain why Scap is subject to endoplasmic reticulum retention upon Insig-1 binding, whereas 3-hydroxy-3-methylglutaryl coenzyme A reductase is ubiquitinated and degraded.

Juxtamembranous aspartic acid in Insig-1 and Insig-2 is required for cholesterol homeostasis

Insig-1 and Insig-2 are closely related proteins of the endoplasmic reticulum (ER) that mediate feedback control of cholesterol synthesis by sterol-dependent binding to the following two membrane proteins: the escort protein Scap, thus preventing proteolytic processing of sterol regulatory element-binding proteins; and the cholesterol biosynthetic enzyme 3-hydroxy-3-methylglutaryl CoA reductase, thus inducing the ubiquitination and ER-associated degradation of the enzyme. Here, we report that the conserved Asp-205 in Insig-1, which abuts the fourth transmembrane helix at the cytosolic side of the ER membrane, is essential for its dual function. When Asp-205 was mutated to alanine, the mutant Insig-1 lost the ability to bind to Scap and, thus, was unable to suppress the cleavage of sterol regulatory element-binding proteins. The mutant Insig-1 was ineffective also in accelerating sterol-stimulated degradation of 3-hydroxy-3-methylglutaryl CoA reductase. Alanine substitution of the corresponding aspartic acid in Insig-2 produced the same dual defects. These studies identify a single amino acid residue that is crucial for the function of Insig proteins in regulating cholesterol homeostasis in mammalian cells.

Proteasomal degradation of ubiquitinated Insig proteins is determined by serine residues flanking ubiquitinated lysines

Insig-1 and Insig-2 are closely related proteins of the endoplasmic reticulum that play crucial roles in cholesterol homeostasis by inhibiting excessive cholesterol synthesis and uptake. In sterol-depleted cells Insig-1 is degraded at least 15 times more rapidly than Insig-2, owing to ubiquitination of Lys-156 and Lys-158 in Insig-1. In this study, we use domain-swapping methods to localize amino acid residues responsible for this differential degradation. In the case of Insig-2, Glu-214 stabilizes the protein by preventing ubiquitination. When Glu-214 is changed to alanine, Insig-2 becomes ubiquitinated, but it is still not degraded as rapidly as ubiquitinated Insig-1. The difference in the degradation rates is traced to two amino acids: Ser-149 in Insig-1 and Ser-106 in Insig-2. Ser-149, which lies NH(2)-terminal to the ubiquitination sites, accelerates the degradation of ubiquitinated Insig-1. Ser-106, which is COOH-terminal to the ubiquitination sites, retards the degradation of ubiquitinated Insig-2. The current studies indicate that the degradation of ubiquitinated Insigs is controlled by serine residues flanking the sites of ubiquitination.

CYP17, CYP1A1 and COMT polymorphisms and the risk of adenomyosis and endometriosis in Taiwanese women

BACKGROUND

The aim of the study was to test whether the COMT, CYP1A1 and CYP17 genes influence the risk of developing adenomyosis and endometriosis.

METHODS

We conducted two case-control studies, where the cases (n = 198) had either of the two diseases, and controls (n = 312) were disease-free women. For the COMT gene, we selected the G/A nonsynonymous single-nucleotide polymorphism (SNP) that leads to valine-to-methionine (Val/Met) substitution. For the CYP1A1 gene, we used a functional T/C SNP in the 3'-noncoding region, and we genotyped a T/C functional SNP in the 5' region of the CYP17 gene for the present study. Hardy-Weinberg equilibrium was checked in both cases and controls. Logistic regression models were used to evaluate the genetic effect, with adjustment for other covariates.

RESULTS

We found that the homozygous COMT genotype that encodes low enzyme activity had an increased risk for adenomyosis with an age-adjusted odds ratio of 3.2 (95% confidence interval 1.3-7.8; P = 0.006). The COMT gene, however, was not associated with endometriosis. Neither the CYP1A1 nor CYP17 genes had any significant association with either of the two diseases.

CONCLUSION

The COMT gene significantly influences the risk of adenomyosis but not endometriosis. The present study does not provide evidence to support any of the three genes exerting pleiotropic effects on both diseases.

Sterol-regulated ubiquitination and degradation of Insig-1 creates a convergent mechanism for feedback control of cholesterol synthesis and uptake

This paper describes a convergent mechanism for the feedback control of cholesterol synthesis and uptake mediated by SREBPs, membrane bound transcription factors. Endoplasmic reticulum (ER) bound SREBPs form complexes with Scap, a polytopic ER protein. In sterol-overloaded cells, Scap/SREBP binds to Insig-1, which retains the complex in the ER. Upon sterol deprivation, the Scap/SREBP complex dissociates from Insig-1, which is then ubiquitinated on lysines 156 and 158 and degraded in proteasomes. Scap/SREBP moves to the Golgi, where SREBP is processed to liberate a nuclear fragment that activates genes for cholesterol synthesis and uptake and the gene for Insig-1. Ubiquitination is not necessary for release of Scap/SREBP from Insig-1, but it establishes a requirement for synthesis of new Insig-1 for feedback inhibition. When the new Insig-1 and cholesterol converge on Scap, Scap/SREBP binds to Insig-1, preventing ubiquitination. The Insig-1/Scap/SREBP complex accumulates in the ER, ready for liberation when the cell is again sterol deprived.

Risk factors on graft survival of living donor kidney transplantation

Living donors have always been the basic resources of transplantation in our country, where cadaveric harvesting is still hampered for various reasons.

OBJECTIVE

The aim of this study was to compare graft survival rates between living unrelated donor (LURD) and living related donor (LRD), to assess the potential risk factors for the graft survival, and to discuss the role of LURD.

METHOD

From October 1991 to February 2003, 77 living donor renal transplants were performed: 41 were LURD and 36 were LRD transplants. The analyzed variables were donor relationship, recipient age and sex, donor age and sex, HLA-DR mismatching, nonspecific blood transfusion history of donor, acute rejection episodes, repeated rejection episode (more than 3 times), delayed graft function, recurred primary disease, and immunosuppressive regimen. Graft survival rate was assessed with the Kaplan-Meier method and the significance of possible variables with the Cox proportional hazard model.

RESULTS

Eleven recipients lost their grafts (6 from LURD and 5 from LRD), most of them are due to chronic rejection (n = 7). Overall 3-, 5- and 10-year graft survival in live donors were 92.8%, 86.6%, and 76.9%, respectively. Graft survival at 3, 5, and 10 years being 91.9%, 88.5%, and 74.7% for the LURD versus 94%, 84%, and 78.8% for LRD transplants (P > .05). Acute rejection episodes, especially more than 3 times (risk ratio [RR] = 11.1) and preoperative multiple transfusion history (RR = 4.2) were significant factors on graft survival in our series.

CONCLUSION

Acute rejection episodes markedly decreased the long-term graft survival in live donor renal transplants. The use of LURD transplants provides graft survival comparable with LRD transplants and proper management to acute rejection is essential for long-term graft survival.

Comparison of survival probabilities for living-unrelated versus cadaveric renal transplant recipients

Any attempt to improve organ donation would be of benefit due to the growing shortage of cadaveric sources for transplantation.

OBJECTIVE

We compared the graft survivals and possible predictive variables among renal transplant recipients with organs from living unrelated (LURD) versus cadaveric donors (CD).

METHOD

Among 104 consecutive renal transplants performed from July 1992 to February 2003, 41 were from LURD and 24 from CD. Immunosuppressive regimens were based on cyclosporine and steroids with mycophenolate mofetil added after 1998. Patient and graft survivals were estimated using the Kaplan-Meier method and compared using log-rank tests. The significance level of predictive variables was analyzed with the Cox proportional hazard model. The follow-up period was 2 to 127 months (median 46 months).

RESULTS

Eight recipients lost their grafts (six from LURD and two from CD) due to four chronic rejections, one acute rejection, one recurrence of primary disease, and one death with a functioning graft. The graft survival rates at 1, 3, 5, and 7 years were 97.6%, 91.9%, 88.5%, and 82.2% for LURD transplants versus 95.5%, 90.9%, 90.9%, and 90.9% for CD transplants, respectively (P > .05). Delayed graft function and donor age (>55 years old) were statistically significant predictors of graft survival among LURD transplants. Donor age (>55 years old) and multiple preoperative transfusion history were significant in CD transplants.

CONCLUSION

LURD transplant survival was similar to that of CD transplants in our series. LURDs are an excellent source of organs to expand the donor pool.

Proteolytic activation of sterol regulatory element-binding protein induced by cellular stress through depletion of Insig-1

Insig-1 and Insig-2 are closely related proteins of the endoplasmic reticulum (ER) that block proteolytic activation of sterol regulatory element-binding proteins (SREBPs), membrane-bound transcription factors that activate synthesis of cholesterol and fatty acids in animal cells. When cellular cholesterol levels are high, Insig proteins bind to SREBP cleavage-activating protein, retaining it in the ER and preventing it from escorting SREBPs to the site of proteolytic activation in the Golgi complex. Here we report that hypotonic stress reverses the sterol-mediated inhibition of SREBP proteolytic activation by reducing the level of Insig-1 but not Insig-2. The reduction of Insig-1, a protein with a rapid turnover rate, results from a general inhibition of protein synthesis mediated by hypotonic stress. Insig-2 is not affected by hypotonic stress because of its slower turnover rate. Inhibition of protein synthesis by hypotonic shock has not been reported previously. Thapsigargin, an activator of the ER stress response, also inhibits protein synthesis and activates proteolysis of SREBP. Such activation also correlates with the disappearance of Insig-1. The current study demonstrates that animal cells, in response to either hypotonic shock or ER stress, can bypass the cholesterol inhibition of SREBP processing, an effect that is attributable to the rapid turnover of Insig-1.

Practical application of fMRI for surgical planning

We report our experience evaluating tasks designed to visualize regions of motor and language brain activation using functional magnetic resonant imaging (fMRI). Our goal was to identify a battery of tasks which would provide a range of brain imaging studies which could be used clinically for surgical planning, with the requirement that they could be performed and analyzed rapidly, thus, cost effectively. These tasks were chosen to assess (1) motor control of the hands, fingers, and feet, and (2) language processing using both auditory and visual task presentations. From January through April 2001, five patients and eight normal subjects were studied. A selection of three or four tasks acquired with an EPI sequence coupled with a high resolution 3D MR sequence were completed in 45- 60 min of scanner time. Identification of the location of eloquent cortex serving aspects of motor and language functions was successful in four of the five patients and all of the eight normal subjects.

Effect of hormone replacement therapy on uterine fibroids in postmenopausal women—a 3-year study

OBJECTIVE

The aim of this prospective 3-year clinical study was to examine the effect of hormone replacement therapy (HRT) on uterine fibroid growth among postmenopausal women.

METHODS

Thirty-seven postmenopausal women with uterine solitary fibroids were recruited randomly for HRT in a 3-year program. All participants received 0.625 mg conjugated equine estrogen (CEE) and 5 mg medroxyprogesterone (MPA) daily. Fibroid volume was measured by transvaginal ultrasonography at baseline and then at 12-month intervals for 3 times. Clinically, significant fibroid growth was defined as an increase in volume of more than 25% compared with baseline. Also, 35 postmenopausal women with uterine fibroid were studied as control who did not receive HRT during the study period.

RESULTS

Fibroid volume had increased significantly after 1 year both in HRT users and non-users. These increases continued to the second year significantly in HRT users but not in non-users. However, the volumes declined significantly at the third year to similar levels as those measured at baseline in control. In HRT users, fibroid volume though significantly increased at the third year (vs. baseline) but declined insignificantly in comparison with the second year. Clinically, at end of the third year study, one of 34 and three of 34 women increased fibroid volume over 25% compared with baseline in HRT non-users and users, respectively.

CONCLUSIONS

HRT does increase uterine fibroid volume statistically. However, its effect appears in the first 2 years of use. The increased fibroid volume begins to decline at the third year both in HRT users and non-users. Clinically, the increased effect of HRT on uterine fibroid of postmenopausal women should be not over-emphasized at least for 3 years of usage.

Structure and alternative splicing of the rat 7-dehydrocholesterol reductase gene

The enzyme 7-dehydrocholesterol reductase (Dhcr7) catalyzes the reduction of 7-dehydrocholesterol (DHC), the terminal reaction of the pathway of cholesterol biosynthesis. We report the isolation and characterization of the genomic DNA encoding rat Dhcr7 that contains nine exons and eight introns distributed over 15944 nucleotides (nts) and a consensus GT-AG at each exon/intron junction. Unexpectedly, we have found the occurrence of at least five isoforms of Dhcr7, designated as Dhcr7-AS (alternatively spliced)-1 (1474 nts), -2 (1595 nts), -3 (1602 nts), -4 (1723 nts) and -5 (1287 nts), which was believed to be caused by alternative usage of three 5' noncoding exons. Furthermore, Dhcr7-AS-1 was found to be differentially expressed in six tissues examined while Dhcr7-AS-2 was expressed mainly in liver and brain. Interestingly, human Dhcr7 gene in HepG2 cells produced no detectable isoform while mouse Dhcr7 gene in L929 cells produced three isoforms, suggesting a difference in alternative splicing between species. Thus, regulation of Dhcr7 through the combined mechanisms of tissue-specific transcription and differential alternative splicing appears unique among enzymes characterized from the entire post-lanosterol pathway in cholesterol biosynthesis.

Akt activation by estrogen in estrogen receptor-negative breast cancer cells

It has been a common belief that estrogen regulates cellular responses through binding to its receptor, the estrogen receptor (ER). In the nucleus, estrogen modulates the expression of estrogen-responsive genes through the action of the ER at the transcriptional level. In the cytoplasm, the ER-dependent signaling pathway has been shown to be involved in the activation of Akt and the downstream molecules. It is not clear, however, whether estrogen can modulate cytoplasmic signaling in an ER-independent manner. Human breast cancer cell lines without detectable ERs such as MDA-MB-435 and MDA-MB-231 were treated in estrogen-depleted medium followed by a brief treatment with estrogen. The activation of Akt was evaluated by a phosphoserine antibody. Our results showed that estrogen stimulated Akt activation, as indicated by phosphorylation at Ser(473) of the oncoprotein, in ER-negative breast cancer cells. Activation of Akt by estrogen in these cells was time and dose dependent and could be blocked by inhibitors of phosphatidylinositol 3'-kinase and Src kinase but not by estrogen antagonists. Our results provide evidence as well as the mechanism of the receptor-independent function of estrogen, in which the antiapoptotic factor Akt is activated.

Pseudo-Meigs syndrome and elevated levels of tumor markers associated with benign ovarian tumors--two case reports

Elevated tumor markers for a post-menopausal woman presenting with a multilocular adnexal mass, ascites, and pleural effusion were interpreted as being highly suspicious of malignancy. This paper describes two cases of ovarian tumors presenting with all signs of malignancy. Following surgical excision of the masses, and histopathological assay, a benign pure struma ovarii and a mucinous cystadenoma were diagnosed by pathologists. The immediate and complete resolution of symptoms were achieved post-operatively, and the previously-evident abnormal tumor markers rapidly declined to the normal range, the two tumors were subsequently classified as pseudo-Meigs' syndromes.

Quality of life issues in motor neurone disease: the development and validation of a coping strategies questionnaire, the MND Coping Scale

A person's ability to cope with having motor neurone disease may be an important factor in determining their quality of life. We have developed a scale to measure coping strategies in people with MND. A disease-specific and patient-focused approach was employed. Open-ended interviews were used to generate initial items. Coping with the condition was an important consideration for all subjects. The final scale was administered to a sample of 44 people with MND. A factor analysis of the results demonstrated subscales comprised of distinct styles of coping. Reliability and validity were demonstrated within individual subscales. Significant correlations were shown between coping styles and psychological well being, disease duration and disability. Although still at a preliminary stage of development, the MND Coping Scale is proposed as a useful tool for further longitudinal study of coping in MND, with the potential to discover cause effect relationships between coping and psychological outcome.

web-based interactive data processing: application to stable isotope metrology

To address a fundamental need in stable isotope metrology, the National Institute of Standards and Technology (NIST) has established a web-based interactive data-processing system accessible through a common gateway interface (CGI) program on the internet site http://www. nist.gov/widps-co2. This is the first application of a web-based tool that improves the measurement traceability afforded by a series of NIST standard materials. Specifically, this tool promotes the proper usage of isotope reference materials (RMs) and improves the quality of reported data from extensive measurement networks. Through the International Atomic Energy Agency (IAEA), we have defined standard procedures for stable isotope measurement and data-processing, and have determined and applied consistent reference values for selected NIST and IAEA isotope RMs. Measurement data of samples and RMs are entered into specified fields on the web-based form. These data are submitted through the CGI program on a NIST Web server, where appropriate calculations are performed and results returned to the client. Several international laboratories have independently verified the accuracy of the procedures and algorithm for measurements of naturally occurring carbon-13 and oxygen-18 abundances and slightly enriched compositions up to approximately 150% relative to natural abundances. To conserve the use of the NIST RMs, users may determine value assignments for a secondary standard to be used in routine analysis. Users may also wish to validate proprietary algorithms embedded in their laboratory instrumentation, or specify the values of fundamental variables that are usually fixed in reduction algorithms to see the effect on the calculations. The results returned from the web-based tool are limited in quality only by the measurements themselves, and further value may be realized through the normalization function. When combined with stringent measurement protocols, two- to threefold improvements have been realized in the reproducibility of carbon-13 and oxygen-18 determinations across laboratories.