Hepatoprotective effects of selenium during diabetes in rats

The present study investigated the hepatoprotective role of selenium during alloxan-induced diabetes in rats. Male Wistar rats were divided into four groups, namely, normal control, selenium treated, diabetic, and selenium-treated diabetic. Diabetes was induced in the animals by injecting alloxan intraperitoneally at a dose rate of 150 mg/kg body weight. Selenium in the form of sodium selenite was supplemented to rats at a dose level of 1 ppm in drinking water, ad libitum for two time durations of 2 and 4 weeks. The effects of different treatments were studied on various parameters in rat liver, which included serum glucose levels, serum insulin levels, alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), lipid peroxidation (LPO), glutathione reduced (GSH), oxidized glutathione (GSSG), total glutathione (TG), superoxide dismutase (SOD), catalase (CAT), glutathione reductase, glutathione peroxidase, metallothionein (MT), and histoarchitecture. A significant increase in the serum glucose levels, LPO levels, and in enzyme activities of ALP, ALT, and AST was observed in diabetic rats which, however, got decreased significantly upon supplementation with selenium. On the contrary, decreased enzyme activities of GSSG, SOD, and CAT and depressed levels of GSH as well as serum insulin levels were observed in diabetic rats which got improved following selenium supplementation. Interestingly, MT levels were increased both in diabetic and selenium-treated diabetic rats. Further, marked alterations in histoarchitecture were seen in diabetic rats with the prominent features being congestion in sinusoids, lipid accumulation, and centrilobular hepatocyte degeneration. However, selenium treatment to diabetic rats showed overall improvement in the hepatic histoarchitecture.

Correlation of two-photon in vivo imaging and FIB/SEM microscopy

Advances in the understanding of brain functions are closely linked to the technical developments in microscopy. In this study, we describe a correlative microscopy technique that offers a possibility of combining two-photon in vivo imaging with focus ion beam/scanning electron microscope (FIB/SEM) techniques. Long-term two-photon in vivo imaging allows the visualization of functional interactions within the brain of a living organism over the time, and therefore, is emerging as a new tool for studying the dynamics of neurodegenerative diseases, such as Alzheimer’s disease. However, light microscopy has important limitations in revealing alterations occurring at the synaptic level and when this is required, electron microscopy is mandatory. FIB/SEM microscopy is a novel tool for three-dimensional high-resolution reconstructions, since it acquires automated serial images at ultrastructural level. Using FIB/SEM imaging, we observed, at 10 nm isotropic resolution, the same dendrites that were imaged in vivo over 9 days. Thus, we analyzed their ultrastructure and monitored the dynamics of the neuropil around them. We found that stable spines (present during the 9 days of imaging) formed typical asymmetric contacts with axons, whereas transient spines (present only during one day of imaging) did not form a synaptic contact. Our data suggest that the morphological classification that was assigned to a dendritic spine according to the in vivo images did not fit with its ultrastructural morphology. The correlative technique described herein is likely to open opportunities for unravelling the earlier unrecognized complexity of the nervous system.

F-box protein Fbxl18 mediates polyubiquitylation and proteasomal degradation of the pro-apoptotic SCF subunit Fbxl7

Fbxl7, a subunit of the SCF (Skp-Cul1-F-box protein) complex induces mitotic arrest in cells; however, molecular factors that control its cellular abundance remain largely unknown. Here, we identified that an orphan F-box protein, Fbxl18, targets Fbxl7 for its polyubiquitylation and proteasomal degradation. Lys 109 within Fbxl7 is an essential acceptor site for ubiquitin conjugation by Fbxl18. An FQ motif within Fbxl7 serves as a molecular recognition site for Fbxl18 interaction. Ectopically expressed Fbxl7 induces apoptosis in Hela cells, an effect profoundly accentuated after cellular depletion of Fbxl18 protein or expression of Fbxl7 plasmids encoding mutations at either Lys 109 or within the FQ motif. Ectopic expression of Fbxl18 plasmid-limited apoptosis caused by overexpressed Fbxl7 plasmid. Thus, Fbxl18 regulates apoptosis by mediating ubiquitin-dependent proteasomal degradation of the pro-apoptotic protein Fbxl7 that may impact cellular processes involved in cell cycle progression.

A pilot study of the SARC-F scale on screening sarcopenia and physical disability in the Chinese older people

INTRODUCTION

The SARC-F scale is a newly developed tool to diagnose sarcopenia and obviate the need for measurement of muscle mass. SARC-F ≥ 4 is defined as sarcopenia. The questions of SARC-F cover physical functions targeting sarcopenia or initial presentation for sarcopenia. The aim of the study is to explore the application of SARC-F in the Chinese people.

METHODS

Two hundred thirty Chinese people over 65 years old were assessed by the SARC-F scale, PSMS, Lawton IADL and the shortened version of the falls efficacy scale-international(the short FES-I). Hospitalization was investigated. Physical performance and strength were measured. The association of SARC-F with other scales or tests was analyzed.

RESULTS

Poor physical performance and grip strength were associated with SARC-F ≥ 4 independently (P<0.005). The κ value for agreement of SARC-F ≥ 4 and cutoff points of tests were 0.391 to 0.635. The short FES-I were correlated to SARC-F scores (Spearman's coefficient 0.692). Poor PSMS and Lawton IADL scores were associated with SARC-F ≥ 4(P=0.000) and SARC-F ≥ 4 was associated with hospitalization in the past 2 years (P=0.000).

CONCLUSION

The SARC-F scale can identify old Chinese people with impaired physical function who may suffered from sarcopenia. SARC-F judgment reflects fear of falling, indicates the hospitalization events and is associated with ability of daily life. Thus, SARC-F may be a simple and useful tool for screening individuals with impaired physical function. Further studies on SARC-F in Chinese people would be worthy.

Multiple target-specific molecular agents for detection and image analysis of breast cancer characteristics in mice

Breast cancer is a heterogenetic tumor at the cellular level with multiple factors and components. The inconsistent expression of molecular markers during disease progression reduces the accuracy of diagnosis and efficacy of target-specific therapy. Single target-specific imaging agents can only provide limited tumor information at one time point. In contrast, multiple target-specific imaging agents can increase the accuracy of diagnosis. The aim of this study was to demonstrate the ability of multi-agent imaging to discriminate such differences in single tumor. Mice bearing human cancer cell xenografts were tested to determine individual differences under optimal experimental conditions. Neovasculature agent (RGD peptide), tumor stromal agent (matrix metalloproteinase), and tumor cell markers (epidermal growth factor, Her-2, interleukin 11) imaging agents were labeled with reporters. 18F-Fluorodeoxyglucose was used to evaluate the tumor glucose status. Optical, X-ray, positron emission tomography, and computer tomography imaging modalities were used to determine tumor characteristics. Tumor size and imaging data demonstrated that individual differences exist under optimal experimental conditions. The target-specific agents used in the study bind to human breast cancer cell lines in vitro and xenografts in vivo. The pattern of binding corresponds to that of tumor markers. Multi-agent imaging had complementary effects in tumor detection. Multiple noninvasive imaging agents and modalities are complementary in the interrogation of unique biological information from each individual tumor. Such multi-agent approaches provide methods to study several disease components simultaneously. In addition, the imaging results provide information on disease status at the molecular level.

Neuregulin-1 protects against doxorubicin-induced apoptosis in cardiomyocytes through an Akt-dependent pathway

In previous studies, it has been shown that recombinant human neuregulin-1(rhNRG-1) is capable of improving the survival rate in animal models of doxorubicin (DOX)-induced cardiomyopathy; however, the underlying mechanism of this phenomenon remains unknown. In this study, the role of rhNRG-1 in attenuating doxorubicin-induce apoptosis is confirmed. Neonatal rat ventricular myocytes (NRVMs) were subjected to various treatments, in order to both induce apoptosis and determine the effects of rhNRG-1 on the process. Activation of apoptosis was determined by observing increases in the protein levels of classic apoptosis markers (including cleaved caspase-3, cytochrome c, Bcl-2, BAX and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) staining). The activation of Akt was detected by means of western blot analysis. The study results showed that doxorubicin increased the number of TUNEL positive cells, as well as the protein levels of cleaved caspase-3 and cytochrome c, and reduced the ratio of Bcl-2/Bax. However, all of these effects were markedly antagonized by pretreament with rhNRG-1. It was then further demonstrated that the effects of rhNRG-1 could be blocked by the phosphoinositole-3-kinase inhibitor LY294002, indicating the involvement of the Akt process in mediating the process. RhNRG-1 is a potent inhibitor of doxorubicin-induced apoptosis, which acts through the PI3K-Akt pathway. RhNRG-1 is a novel therapeutic drug which may be effective in preventing further damage from occurring in DOX-induced damaged myocardium.

Multiple target-specific molecular imaging agents detect liver cancer in a preclinical model

Liver cancer is the fifth most common cause of cancer deaths worldwide. Noninvasive diagnosis is difficult and the disease heterogeneity reduces the accuracy of pathological assays. Improvement in diagnostic imaging of specific molecular disease markers has provided hope for accurate and early noninvasive detection of liver cancer. However, all current imaging technologies, including ultrasonography, computed tomography (CT), positron emission tomography (PET), and magnetic resonance imaging, are not specific targets for detection of liver cancer. The aim of this study was to test the feasibility of injecting a cocktail of specific molecular imaging agents to noninvasively image liver cancer. The target-specific cocktail contained agents for imaging the neovasculature (RGD peptide), matrix metalloproteinase (MMP), and glucose transport (¹⁸F-fluorodeoxyglucose [¹⁸F-FDG]). Imaging studies were performed in liver cancer cells and xenograft models. The distribution of MMP at the intracellular level was imaged by confocal microscopy. RGD, MMP, and ¹⁸F-FDG were imaged on tumor-bearing mice using PET, CT, X-ray, and multi-wavelength optical imaging modalities. Image data demonstrated that each agent bound to a specific disease target component. The same liver cancer xenograft contained multiple disease markers. Those disease markers were heterogenetically distributed in the same tumor nodule. The molecular imaging agents had different distributions in the whole body and inside the tumor nodule. All target-specific agents yielded high tumor-to-background ratios after injection. In conclusion, target-specific molecular imaging agents can be used to study liver cancer in vitro and in vivo. Noninvasive multimodal/multi-target-specific molecular imaging agents could provide tools to simultaneously study multiple liver cancer components.

Heme oxygenase-1: a molecular brake on hepatocellular carcinoma cell migration

Hepatocellular carcinoma (HCC) is a fatal disease with great public health impact worldwide. Heme oxygenase (HO)-1 has recently been reported as an important player in tumor angiogenesis and metastasis. However, the role of HO-1 in liver cancer metastasis is unclear. In this study, we explored genetic differences and downstream signal transduction pathways of HO-1 in liver cancer cell lines. HO-1 wild-type and mutant cell lines were generated from human liver cancer cell line HepG2. The overexpression of wild-type HO-1 decreased the migration of HepG2 cells. In contrast, the overexpression of mutant HO-1G143H increased the migration of the cancer cells. Interleukin (IL)-6 is one of the major downstream molecules that mediated this process because IL-6 expression and migration are suppressed by HO-1 and increased when HO-1 is knocked down by shRNA. In addition, we demonstrated carbon monoxide (CO) and p38MAPK are the cofactors in this signal pathway. In vivo animal model demonstrated HO-1 inhibited the tumor growth. In conclusion, in vitro and in vivo data show HO-1 inhibits the human HCC cells migration and tumor growth by suppressing the expression of IL-6. The heme degradation product CO is a cofactor in this process and inhibits p38MAPK phosphorylation.

First Report of Yam mild mosaic virus in Yam in Guangxi Province, China

Yams (Dioscorea spp.) are widely grown in China as vegetables and herbal medicine. However, studies on viral diseases on yams are still limited. As a pilot project of a government initiative for improving yam productivity, a small study was conducted in Guangxi, a southern province of China, on viral disease in yams. Incidence of virus-like disease for the three extensively grown D. alata cultivars, GH2, GH5, and GH6, were 12 to 40%, 12 to 29%, and 11 to 25%, respectively, as found in a field survey with a five-plot sampling method in 2010. A total of 112 leaf samples showing mosaic or mottling or leaves without symptoms were collected from the cvs. GH2, GH5, GH6, and seven additional cultivars (D. alata cvs. GY2, GY23, GY47, GY69, GY62, GY72, and D. batatas cv. Tiegun). To determine if the symptoms were caused by Yam mild mosaic virus (YMMV; genus Potyvirus, family Potyviridae), total RNA was extracted from leaves with a commercial RNA purification kit (TIANGEN, Beijing, China), and reverse-transcription (RT)-PCR was conducted with a YMMV-specific primer pair (4) that amplifies the 3'-terminal portion of the viral genome. A PCR product with the predicted size of 262 bp was obtained from samples of GH5 (number testing positive of total number of leaves = 5 of 12), GH6 (24 of 42), and GY72 (1 of 1), but not from asymptomatic leaves. PCR products from a GH5 sample (YMMV-Nanning) and a GH6 sample (YMMV-Luzhai) were cloned and sequenced using an ABI PRISM 3770 DNA Sequencer. The two PCR products were 97% identical at nucleotide (nt) level and with the highest homology (89% identity) to a YMMV isolate (GenBank Accession No. AJ305466). To further characterize the isolates, degenerate primers (2) were used to amplify viral genome sequence corresponding to the C-terminal region of the nuclear inclusion protein b (NIb) and the N-terminal region of the coat protein (CP). These 781-nt fragments were sequenced and a new primer, YMMV For1 (5'-TTCATGTCGCACAAAGCAGTTAAG-3') corresponding to the NIb region, was designed and used together with primer YMMV UTR 1R to amplify a fragment that covers the complete CP region of YMMV by RT-PCR. These 1,278-nt fragments were sequenced (GenBank Accession Nos. JF357962 and JF357963). CP nucleotide sequences of the YMMV-Nanning and YMMV-Luzhai isolates were 94% similar, while amino acid sequences were 99% similar. BLAST searches revealed a nucleotide identity of 82 to 89% and a similarity of 88 to 97% for amino acids to sequences of YMMV isolates (AF548499 and AF548519 and AAQ12304 and BAA82070, respectively) in GenBank. YMMV is known to be prevalent on D. alata in Africa and the South Pacific, and has recently been identified in the Caribbean (1) and Colombia (3). To our knowledge, this is the first report of the natural occurrence of YMMV in China and it may have implications for yam production and germplasm exchange within China. References: (1) M. Bousalem and S. Dallot. Plant Dis. 84:200, 2000. (2) D. Colinet et al. Phytopathology 84:65, 1994. (3) S. Dallot et al. Plant Dis. 85:803, 2001. (4) R. A. Mumford and S. E. Seal. J. Virol. Methods 69:73, 1997.

Sequence analysis and expression mapping of the rat clustered protocadherin gene repertoires

Three closely-linked clusters of protocadherin (Pcdh) genes (alpha, beta, and gamma) encoding more than 50 distinct mRNAs have been identified in humans and mice, and proposed to play important roles in neuronal connectivity in the CNS. The human and mouse Pcdh alpha and gamma clusters each span a region of about 300 kb genomic DNA, and are each organized into a tandem array of more than a dozen highly-similar "variable" exons, and three downstream "constant" exons. Little is known about the expression patterns of the alpha and gamma repertoires in the CNS. Here, we comprehensively analyzed the one megabase rat Pcdh genomic DNA sequences at the nucleotide level using various computational methods. We found that the clustered rat Pcdh genes display strict orthologous relationships with those of mice but not humans. Moreover, each rat Pcdh variable exon is preceded by a distinct promoter. We designed two complete sets of isoform-specific probes and extensively mapped the expression patterns for each member of the alpha and gamma repertoires in the adult rat CNS by non-isotopic in situ hybridization experiments. We found that most alpha and gamma mRNA isoforms are broadly expressed in similar patterns in subsets of cells (with some displaying interesting cortical layer-specific expression) throughout various CNS regions, including the olfactory bulb, cerebral cortex, hippocampus, cerebellum, and spinal cord. The broad expression of most alpha or gamma mRNAs throughout various regions of the CNS is consistent with the hypothesis that these genes may be used for neurons to establish their individuality and also provide the adhesive diversity required for complex synaptic connectivity in the mammalian CNS.

DSS1 is required for the stability of BRCA2

DSS1 is an evolutionarily conserved acidic protein that binds to BRCA2. However, study of the function of DSS1 in mammalian cells has been hampered because endogenous DSS1 has not been detectable by Western blotting. Here, we developed a modified Western blotting protocol that detects endogenous DSS1 protein, and used it to study the function of DSS1 and its interaction with BRCA2 in mammalian cells. We found that essentially all BRCA2 in human cell lines is associated with DSS1. Importantly, we found that RNAi knockdown of DSS1 in human cell lines led to dramatic loss of BRCA2 protein, mainly due to its increased degradation. Furthermore, the stability of BRCA2 mutant devoid of the DSS1-binding domain is unaffected by the depletion of DSS1. Most notably, like BRCA2 depletion, DSS1 depletion also led to hypersensitivity to DNA damage. These results demonstrated that the stability of BRCA2 protein in mammalian cells depends on the presence of DSS1. Deletion or mutation of DSS1 or suppression of its expression by other mechanisms are therefore potential causative mechanisms for human breast and ovarian cancer. Such mechanisms may be relevant to sporadic as well as familiar breast cancer where BRCA1 and BRCA2 mutations are not present.

[A study on apoptosis induced by As₂O₃ for small cell lung cancer]

BACKGROUND

To study apoptosis of small cell lung cancer (SCLC) cell induced by As₂O₃ and enhancement effect of interferon (IFN) on As₂O₃.

METHODS

DNA gel electrophoresis, terminal deoxynucleotidyl transferase nick end labeling (TUNEL) and immunocytochemistry were used to detect the apoptosis induced by As₂O₃ with different doses and time and the expression of Bcl-2 or PCNA.

RESULTS

Within certain extent of concentration, As₂O₃ could induce apoptosis of SCLC cells. And apoptotic cells increased and expression of Bcl 2 and PCNA decreased with time prolonged or dose increased. The apoptosis inducing effect of As₂O₃ combined with IFN was much higher than that of As₂O₃ alone.

CONCLUSIONS

As₂O₃ may induce apoptosis of SCLC cells and the efficiency of apoptosis is related to dose and time. IFNα-2b might enhance the effect of apoptosis on SCLC induced by As₂O₃.

A randomized clinical trial of 4-hydroxyphenylretinamide for high-grade squamous intraepithelial lesions of the cervix

PURPOSE

Previous trials of topical trans-retinoic acid treatment of cervical intraepithelial neoplasia (CIN) grades 2 and 3 led to a statistically significant regression of CIN 2, but not CIN 3. We tested N-(4-hydroxyphenyl)retinamide (4-HPR), a promising oral retinoid that has been shown to induce apoptosis through nonretinoic receptor acid-mediated pathways, for its toxicity and efficacy against CIN 2/3.

EXPERIMENTAL DESIGN

In a blinded randomized trial, 4-HPR at 200 mg/day for 6 months (with a 3-day/month drug holiday) was compared with placebo in patients with biopsy-proven CIN-2/3 [high-grade squamous intraepithelial lesions (HGSILs)]. Patients were treated with placebo or 4-HPR for 6 months, biopsied, and then followed for an additional 6 months. At the 12-month end point, they underwent either loop excision if a histological lesion was present or a biopsy from the original area of the lesion if no lesion was present.

RESULTS

An interim analysis of blinded data showed a significantly worse prognosis at 12 months for one group. When the code was broken because of the poorer outcomes, we discovered that the 4-HPR treatment arm was performing more poorly than was the placebo at 6 and 12 months (25 versus 44% response rates at 6 months; 14 versus 50% at 12 months). Toxicity was not significant in either arm.

CONCLUSIONS

4-HPR at 200 mg/day with a 3-day/month drug holiday is not active compared with placebo in the treatment of HGSIL. Because 4-HPR is active in the laboratory, the lack of effect in our trial may indicate that higher doses are needed in patients to achieve comparable results.

Effects of novel phenylretinamides on cell growth and apoptosis in bladder cancer

Superficial bladder cancer is a major target for chemoprevention. Retinoids are important modulators of epithelial differentiation and proliferation and are effective in the treatment and prevention of several epithelial cancers. One class of compounds, the retinamides, is structurally similar to other retinoids but have the added feature of being potent apoptosis inducers. Among these, fenretinide (N-[4-hydroxyphenyl]retinamide), or 4HPR, has promise for bladder cancer chemoprevention and is currently under Phase III study in this setting. In addition to 4HPR, there are several new structurally related phenylretinamides bearing hydroxyl, carboxyl, or methoxyl residues on carbons 2, 3, and 4 of the terminal phenylamine ring [designated N-(2-hydroxyphenyl)retinamide, N-(3-hydroxyphenyl)retin amide, N-(2-carboxyphenyl)retin- amide, N-(3-carboxyphenyl)retin amide, N-(4-carboxy- phenyl)retinamide, and N-(4-methoxyphenyl)retinamide, respectively]. The objective of this study was to compare the growth inhibitory and apoptotic effects of these phenylretinamides with 4HPR in human bladder transitional cell cancer-derived cell lines of varying histological grade (RT4, grade 1; UM-UC9 and UM-UC10, grade 3; and UM-UC14, grade 4) by cell counting, cell cycle fluorescence-activated cell sorter analysis and a dual stain apoptosis assay. All of the seven phenylretinamides reduced cell number, altered the cell cycle distribution, and induced apoptosis when administered at a concentration of 10 microM, which is within the pharmacologically achievable range. Although the relative potencies of the phenylretinamides varied depending on the cell line, N-(3-hydroxy phenyl)retin- amide was the most active with significantly greater growth inhibition than 4HPR in all of the four cell lines. These in vitro findings warrant further study of these novel phenylretinamides, which may have potential as preventive or therapeutic agents in transitional cell cancer.

Identification of effective retinoids for inhibiting growth and inducing apoptosis in bladder cancer cells

PURPOSE

Retinoids modulate the growth and differentiation of normal and malignant epithelial cells in vitro and in vivo, and inhibit bladder carcinogenesis in animal models. Retinoid analogs have been used in several clinical chemoprevention trials of superficial bladder cancer recurrence. There is a clear need to identify new effective retinoids and develop novel approaches for the chemoprevention and treatment of superficial bladder cancer. We investigated the effects of various retinoids on growth inhibition and apoptosis induction in bladder cancer cell lines.

MATERIALS AND METHODS

Ten grades 1 to 3 bladder cancer cell lines and the 4 retinoids all-trans-retinoic acid, 9-cis retinoic acid, 4-(N-hydroxyphenyl) retinamide (4HPR) and LGD1069 were used in the study. We compared the ability of these retinoids to inhibit growth, induce apoptosis, affect the expression of nuclear retinoid receptors and modulate apoptosis related genes.

RESULTS

Most bladder cancer cell lines did not express retinoic acid receptor beta and were resistant to the effect of all-trans-retinoic acid and 9-cis retinoic acid on growth inhibition and apoptosis induction, even at a concentration of 10(-5) M. The 2 cell lines that expressed retinoic acid receptor beta were constitutively sensitive to the growth inhibitory effect of all-trans-retinoic acid. 4HPR inhibited cell growth by about 90% in all but 1 cell line and induced apoptosis at a concentration of 10(-5) M after a 24-hour treatment. LGD1069 had virtually no effect. All-trans-retinoic acid and 4HPR induced retinoic acid receptor beta expression in 1 bladder cancer cell line. However, the effect of 4HPR on cell growth and apoptosis were not related to the constitutive expression of retinoic acid receptor beta. 4HPR decreased bcl-2 expression in 6 of 8 bladder cancer cell lines but did not change p53 gene expression.

CONCLUSIONS

The results demonstrate that 4HPR is the most potent growth inhibitor and apoptosis inducer of the retinoids tested. Lack of retinoic acid receptor beta expression may be responsible for cell resistance to all-trans-retinoic acid but not to the other retinoids.

[Ecophysiological response of Pinus koraiensis seedlings to elevated CO2]

Studies on the ecophysiological response of Pinus koraiensis seedlings were conducted in open-top chambers which were controlled with CO2 concentration of about 500 and 700 mumol.mol-1. The result shows that there were different responses in net photosynthetic rate and stomatal conductance at high CO2(500 and 700 mumol.mol-1) and ambient CO2 concentrations. Under 500 mumol.mol-1 CO2, the carboxylase activity of RuBP was the highest, the photosynthesis showed "up-ward", the average daily net CO2 assimilation was the greatest, and the contents of chlorophyll and soluble sugars were the highest. While under 700 mumol.mol-1 CO2, the photosynthesis showed "down-ward" and was lower than that of the control, and the enzyme activity and the contents of substances were the lowest.