Induction of the human CDC45 gene promoter activity by natural compound trans‑resveratrol

GGAA motifs in the human TP53 and HELB gene promoters play a part in responding to trans‑resveratrol (Rsv) in HeLa S3 cells. This sequence is also present in the 5'‑upstream region of the human CDC45 gene, which encodes a component of CMG DNA helicase protein complex. The cells were treated with Rsv (20 µM), then transcripts and the translated protein were analyzed by quantitative RT‑PCR and western blotting, respectively. The results showed that the CDC45 gene and protein expression levels were induced after the treatment. To examine whether they were due to the activation of transcription, a 5'‑upstream 556‑bp of the CDC45 gene was cloned and inserted into a multi‑cloning site of the Luciferase (Luc) expression vector. In the present study, various deletion/point mutation‑introduced Luc expression plasmids were constructed and they were used for the transient transfection assay. The results showed that the GGAA motif, which is included in a putative RELB protein recognizing sequence, plays a part in the promoter activity with response to Rsv in HeLa S3 cells.

Anticancer sensitivity and biological aspect of 5-fluorouracil-resistant human colorectal cancer HCT116 cells in three-dimensional culture under high- and low-glucose conditions

5-Fluorouracil (5-FU) is a commonly used anticancer drug for colorectal cancer (CRC). Therefore, it is crucial to elucidate the mechanisms that contribute to 5-FU resistance. We established an acquired 5-FU resistant cell line, HCT116RF10, derived from CRC cells and investigated its energy metabolism as well as the underlying mechanism of 5-FU resistance. We examined the sensitivity to 5-FU and the formation of tumor spheres in parental HCT116 cells and 5-FU-resistant HCT116RF10 cells under 3D culture conditions at high-glucose (HG 25 mM) and low-glucose (LG 5.5 mM) concentrations. These results suggested that the tumor spheres of parental HCT116 cells displayed higher sensitivity to 5-FU under LG conditions than under HG conditions. HCT116RF10 tumor spheres exhibited comparable sensitivity to 5-FU under HG and LG conditions. Furthermore, under HG conditions, there was a marked decrease in extracellular lactate in the HCT116RF10 tumor sphere compared to that in the LG tumor sphere. Similarly, HCT116 tumor spheres showed decreased extracellular lactate levels under LG conditions compared to those grown under HG conditions. Moreover, the evidence reveals that the tumor spheres of HCT116RF10 and HCT116 cells exhibit disparate dependencies on energy metabolism, glycolysis, and mitochondrial respiration under both HG and LG conditions. These results have important clinical implications for overcoming 5-FU resistance and enhancing antitumor treatment strategies.

Extracellular Leakage Protein Patterns in Two Types of Cancer Cell Death: Necrosis and Apoptosis

Dead cells release fragments of DNA, RNA, and proteins (including peptides) into the extracellular space. Two major forms of cell death during cancer development have been identified: necrosis and apoptosis. Our group investigated the mechanisms that regulate cell death during the treatment of mouse tumor FM3A cells with the anticancer drug floxuridine (FUdR). In the original strain F28-7, FUdR induced necrosis, whereas in the variant F28-7-A, it induced apoptosis. Here, we report that the extracellular leakage proteome (i.e., the secretome) is involved in these cell death phenomena. The secretome profile, which was analyzed via shotgun proteomic analysis, revealed that altered protein leakage was involved in signal transduction, transcription, RNA processing, translation, and cell death. Notably, the characteristic secretory proteins high mobility group box 1 and 2 were detected in the culture medium of both necrotic and apoptotic cells. Overall, these results indicate that unique cellular events mediated by secretory proteins may be involved in necrosis and apoptosis.

Downregulation of long noncoding RNA TP73-AS1 expression confers resistance to temozolomide in human glioblastoma cells

Glioblastoma multiforme (GBM), the most aggressive primary malignant brain tumor, is resistant to conventional radiotherapies and chemotherapies, including temozolomide (TMZ). Overcoming GBM resistance to the chemotherapeutic agent TMZ poses an important therapeutic problem. This study established an association between the long noncoding RNA TP73-AS1 and TMZ sensitivity regulation in human GBM cells (U87MG). Transcriptomic analysis revealed that TP73-AS1 expression was reduced in TMZ-resistant U87MGRT100 cells compared to that in parental U87MG cells. Additionally, TP73-AS1 knockdown in parental U87MG cells decreased their sensitivity to TMZ. Overall, these findings suggest that TP73-AS1 functions as a regulator of TMZ sensitivity in GBM cells.

Relationship between anticancer sensitivities and cellular respiration properties in 5-fluorouracil-resistant HCT116 human colorectal cancer cells

5-Fluorouracil (5-FU) is widely used for colorectal cancer (CRC) treatment; however, continuous treatment of CRC cells with 5-FU can result in acquired resistance, and the underlying mechanism of 5-FU resistance remains unclear. We previously established an acquired 5-FU-resistant CRC cell line, HCT116R^F10 , and examined its biological features and 5-FU resistance mechanisms. In this study, we evaluated the 5-FU sensitivity and cellular respiration dependency of HCT116R^F10 cells and parental HCT116 cells under conditions of high- and low-glucose concentrations. Both HCT116R^F10 and parental HCT116 cells were more sensitive to 5-FU under low-glucose conditions compared to high-glucose conditions. Interestingly, HCT116R^F10 and parental HCT116 cells exhibited altered cellular respiration dependence for glycolysis and mitochondrial respiration under high- and low-glucose conditions. Additionally, HCT116R^F10 cells showed a markedly decreased ATP production rate compared with HCT116 cells under both high- and low-glucose conditions. Importantly, glucose restriction significantly reduced the ATP production rate for both glycolysis and mitochondrial respiration in HCT116R^F10 cells compared with HCT116 cells. The ATP production rates in HCT116R^F10 and HCT116 cells were reduced by approximately 64% and 23% respectively under glucose restriction, suggesting that glucose restriction may be effective at enhancing 5-FU chemotherapy. Overall, these findings shed light on 5-FU resistance mechanisms, which may lead to improvements in anticancer treatment strategies.

Genomic and biological aspects of resistance to selective poly(ADP-ribose) glycohydrolase inhibitor PDD00017273 in human colorectal cancer cells

BACKGROUND

Poly(ADP-ribose) glycohydrolase (PARG) is a key enzyme in poly(ADP-ribose) (PAR) metabolism and a potential anticancer target. Many drug candidates have been developed to inhibit its enzymatic activity. Additionally, PDD00017273 is an effective and selective inhibitor of PARG at the first cellular level.

AIMS

Using human colorectal cancer (CRC) HCT116 cells, we investigated the molecular mechanisms and tumor biological aspects of the resistance to PDD00017273.

METHODS AND RESULTS

HCT116R^PDD , a variant of the human CRC cell line HCT116, exhibits resistance to the PARG inhibitor PDD00017273. HCT116R^PDD cells contained specific mutations of PARG and PARP1, namely, PARG mutation Glu352Gln and PARP1 mutation Lys134Asn, as revealed by exome sequencing. Notably, the levels of PARG protein were comparable between HCT116R^PDD and HCT116. In contrast, the PARP1 protein levels in HCT116R^PDD were significantly lower than those in HCT116. Consequently, the levels of intracellular poly(ADP-ribosyl)ation were elevated in HCT116R^PDD compared to HCT116. Interestingly, HCT116R^PDD cells did not exhibit cross-resistance to COH34, an additional PARG inhibitor.

CONCLUSION

Our findings suggest that the mutated PARG acquires PDD00017273 resistance due to structural modifications. In addition, our findings indicate that PDD00017273 resistance induces mutation and PARP downregulation. These discoveries collectively provide a better understanding of the anticancer candidate PARG inhibitors in terms of resistance mechanisms and anticancer strategies.

Regulation of 5-fluorodeoxyuridine monophosphate-thymidylate synthase ternary complex levels by autophagy confers resistance to 5-fluorouracil

5-Fluorouracil (5-FU) is a cornerstone drug used to treat colorectal cancer (CRC). However, the prolonged exposure of CRC cells to 5-FU results in acquired resistance. We have previously demonstrated that levels of the 5-fluorodeoxyuridylate (FdUMP) covalent complex with thymidylate synthase (FdUMP-TS) and free-TS (native enzyme) are higher in 5-FU-resistant CRC cells than in the parental cell line (HCT116). Accordingly, resistant cells may have an efficient system for trapping and removing FdUMP-TS, thus imparting resistance. In this study, using a model of 5-FU-resistant CRC cells generated by repeated exposure, the role of autophagy in the elimination of FdUMP-TS in resistant cells was investigated. The resistant cells showed greater sensitivity to autophagy inhibitors than that of parental cells. Autophagy inhibition increased 5-FU cytotoxicity more substantially in resistant cells than in parental cells. Furthermore, autophagy inhibition increased FdUMP-TS protein accumulation in resistant cells. Our findings suggest that resistance to 5-FU is mediated by autophagy as a system to eliminate FdUMP-TS and may guide the use and optimization of combination therapies involving autophagy inhibitors.

Passion fruit seed extract protects beta-amyloid-induced neuronal cell death in a differentiated human neuroblastoma SH-SY5Y cell model

Alzheimer's disease (AD) is a progressive neurodegenerative disease with accompanying perceptive disorder. We previously reported that decreasing levels of brain-derived neurotrophic factor (BDNF) promoted beta-amyloid (Aβ)-induced neuronal cell death in neuron-like differentiated SH-SY5Y (ndSH-SY5Y) human neuroblastoma cells in an AD mimic cell model. We investigated the neuroprotective effects of passion fruit seed extract (PFSE) and one of the main stilbene compounds, piceatannol, in an AD cell model using ndSH-SY5Y cells. Both PFSE and piceatannol were found to protect Aβ-induced neurite fragmentation in the cell model (protection efficacy; 34% in PFSE and 36% in piceatannol). In addition, both PFSE and piceatannol suppress Aβ-induced neuronal cell death in the cell model (inhibitory effect; 27% in PFSE and 32% in piceatannol). Our study is the first to report that piceatannol-rich PFSE can repress Aβ-induced neuronal cell death by protecting against neurite fragmentation in the AD human cell model. These findings suggest that piceatannol-rich PFSE can be considered a potentially neuroprotective functional food for both prevention and treatment of AD.

Trapping of 5-Fluorodeoxyuridine Monophosphate by Thymidylate Synthase Confers Resistance to 5-Fluorouracil

The major metabolite of the anticancer agent 5-fluorouracil (5-FU) is 5-fluorodeoxyuridine monophosphate (FdUMP), which is a potent inhibitor of thymidylate synthase (TS). Recently, we hypothesized that 5-FU-resistant colorectal cancer (CRC) cells have increased levels of TS protein relative to 5-FU-sensitive CRC cells and use a fraction of their TS to trap FdUMP, which results in resistance to 5-FU. In this study, we analyzed the difference between the regulation of the balance of the free, active form of TS and the inactive FdUMP-TS form in 5-FU-resistant HCT116 cells and parental HCT116 cells. Silencing of TYMS, the gene that encodes TS, resulted in greater enhancement of the anticancer effect of 5-FU in the 5-FU-resistant HCT116R^F10 cells than in the parental HCT116 cells. In addition, the trapping of FdUMP by TS was more effective in the 5-FU-resistant HCT116R^F10 cells than in the parental HCT116 cells. Our observations suggest that the regulation of the balance between the storage of the active TS form and the accumulation of FdUMP-TS is responsible for direct resistance to 5-FU. The findings provide a better understanding of 5-FU resistance mechanisms and may enable the development of anticancer strategies that reverse the sensitivity of 5-FU resistance in CRC cells.

Human microRNA hsa-miR-15b-5p targets the RNA template component of the RNA-dependent RNA polymerase structure in severe acute respiratory syndrome coronavirus 2

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused a pandemic of the coronavirus disease in 2019. RNA-dependent RNA polymerase (RdRp) plays an essential role in RNA replication and transcription in SARS-CoV-2. In this study, we focused on the RNA template component of viral RdRp structure and analyzed human microRNAs (miRNAs) targeting specific sequences in this RNA. By examining miRNA databases and using an in vitro RNA-RNA interaction assay, we observed hsa-miR-15b-5p interacting with the RNA component of viral RdRp. Our findings provide evidence that hsa-miR15b-5p may suppresses viral infection and proliferation by targeting the RNA template component of SARS-CoV-2 RdRp.

Molecular Mechanisms and Tumor Biological Aspects of 5-Fluorouracil Resistance in HCT116 Human Colorectal Cancer Cells

5-Fluorouracil (5-FU) is a cornerstone drug used in the treatment of colorectal cancer (CRC). However, the development of resistance to 5-FU and its analogs remain an unsolved problem in CRC treatment. In this study, we investigated the molecular mechanisms and tumor biological aspects of 5-FU resistance in CRC HCT116 cells. We established an acquired 5-FU-resistant cell line, HCT116R^F10. HCT116R^F10 cells were cross-resistant to the 5-FU analog, fluorodeoxyuridine. In contrast, HCT116R^F10 cells were collaterally sensitive to SN-38 and CDDP compared with the parental HCT16 cells. Whole-exome sequencing revealed that a cluster of genes associated with the 5-FU metabolic pathway were not significantly mutated in HCT116 or HCT116R^F10 cells. Interestingly, HCT116R^F10 cells were regulated by the function of thymidylate synthase (TS), a 5-FU active metabolite 5-fluorodeoxyuridine monophosphate (FdUMP) inhibiting enzyme. Half of the TS was in an active form, whereas the other half was in an inactive form. This finding indicates that 5-FU-resistant cells exhibited increased TS expression, and the TS enzyme is used to trap FdUMP, resulting in resistance to 5-FU and its analogs.

Intracellular microRNA expression patterns influence cell death fates for both necrosis and apoptosis

MicroRNAs (miRNAs) are small noncoding RNA molecules that interact with target mRNAs at specific sites to induce cleavage of the mRNA or inhibit translation. Such miRNAs play a vital role in gene expression and in several other biological processes, including cell death. We have studied the mechanisms regulating cell death (necrosis in original F28‐7 cells and apoptosis in their variant F28‐7‐A cells) in the mouse mammary tumor cell line FM3A using the anticancer agent floxuridine (FUdR). We previously reported that inhibition of heat‐shock protein 90 by the specific inhibitor geldanamycin (GA) in F28‐7 cells causes a shift from necrosis to apoptosis. In this study, we investigated the intracellular miRNA expression profiles of FUdR‐treated F28‐7 cells (necrotic condition), GA plus FUdR‐treated F28‐7 cells (apoptotic condition), and FUdR‐treated F28‐7‐A cells (apoptotic condition) through miRNA microarray analysis. In addition, we knocked down Dicer, a key molecule for the expression of mature miRNAs, in F28‐7 cells to examine whether it modulates FUdR‐induced cell death. Our analysis revealed that the miRNA expression patterns differ significantly between these cell death conditions. Furthermore, we identified miRNA candidates that regulate cell death. Knockdown of Dicer in FUdR‐treated necrosis‐fated cells caused a partial shift from necrosis to apoptosis. These findings suggest that modulation of miRNA expression patterns influences the decision of cell death fate toward necrosis or apoptosis. Our findings may serve as a basis for further study of the functions of miRNAs in cell death mechanisms.

Structural Basis of Beneficial Design for Effective Nicotinamide Phosphoribosyltransferase Inhibitors

Inhibition of nicotinamide phosphoribosyltransferase (NAMPT) is an attractive therapeutic strategy for targeting cancer metabolism. So far, many potent NAMPT inhibitors have been developed and shown to bind to two unique tunnel-shaped cavities existing adjacent to each active site of a NAMPT homodimer. However, cytotoxicities and resistances to NAMPT inhibitors have become apparent. Therefore, there remains an urgent need to develop effective and safe NAMPT inhibitors. Thus, we designed and synthesized two close structural analogues of NAMPT inhibitors, azaindole-piperidine (3a)- and azaindole-piperazine (3b)-motif compounds, which were modified from the well-known NAMPT inhibitor FK866 (1). Notably, 3a displayed considerably stronger enzyme inhibitory activity and cellular potency than did 3b and 1. The main reason for this phenomenon was revealed to be due to apparent electronic repulsion between the replaced nitrogen atom (N1) of piperazine in 3b and the Nδ atom of His191 in NAMPT by our in silico binding mode analyses. Indeed, 3b had a lower binding affinity score than did 3a and 1, although these inhibitors took similar stable chair conformations in the tunnel region. Taken together, these observations indicate that the electrostatic enthalpy potential rather than entropy effects inside the tunnel cavity has a significant impact on the different binding affinity of 3a from that of 3b in the disparate enzymatic and cellular potencies. Thus, it is better to avoid or minimize interactions with His191 in designing further effective NAMPT inhibitors.

Direct interaction analysis of microRNA-351-5p and nuclear scaffold lamin B1 mRNA by the cell-free in vitro mRNA/miRNA binding evaluation system

We previously demonstrated that miR-351-5p regulates nuclear scaffold lamin B1 expression and mediates the anticancer floxuridine-induced necrosis shift to apoptosis in mammalian tumor cells. Notably, it is unknown whether lamin B1 mRNA is a direct target of miR-351-5p. Here, we show that miR-351-5p interacts with a lamin B1 mRNA partial sequence by using the cell-free in vitro miRNA and mRNA binding evaluation system. In addition, the interaction of miR-351-5p/lamin B1 mRNA was suppressed by an miR-351-5p inhibitor. Our findings are important in exploring the functions of miRNAs in cellular processes, including cell death.

Association of ABC Transporter With Resistance to FK866, a NAMPT Inhibitor, in Human Colorectal Cancer Cells

BACKGROUND/AIM

Nicotinamide phosphoribosyltransferase (NAMPT), a key enzyme in the NAD⁺ biosynthetic pathway, is a drug target of potent anticancer candidates, including FK866 and other reported NAMPT inhibitors. However, it is known that NAMPT point-mutations render resistance to specific NAMPT inhibitors in several cancer cells. We investigated the resistance mechanisms of NAMPT inhibitor FK866 in human colorectal cancer (CRC) cells.

MATERIALS AND METHODS

We used CRC human cell line HCT116 to determine the expression profiles of FK866-sensitive parental HCT116 cells and FK866-resistant HCT116 (HCT116R^FK866) cells by DNA microarray analysis. The levels of multidrug resistance protein 1 (MDR1) were assessed via western blot. In addition, we analyzed the sensitivity of FK866 in parental HCT116 cells and HCT116R^FK866 cells by co-treatment with MDR1 inhibitor verapamil.

RESULTS

Our results revealed an association between ATP-binding cassette (ABC) transporter gene ABCB1 and resistance to NAMPT inhibitor FK866 in both HCT116R^FK866 cells and parental HCT116 cells. The expression of ABCB1, which encodes MDR1, was lower in HCT116R^FK866 cells than in parental HCT116 cells. Furthermore, the protein level of MDR1/ATP-binding cassette sub-family B member 1 (ABCB1) was 0.5-fold lower in HCT116R^FK866 cells than in parental HCT116 cells. Additionally, HCT116R^FK866 cells showed improved sensitivity to FK866 when co-treated with verapamil, an ABCB1 inhibitor. Interestingly, the efficacy of FK866 in parental HCT116 cells was the same for the treatment with FK866 alone or in combination with verapamil.

CONCLUSION

The change in expression of ABCB1 plays a key role in CRC drug resistance to NAMPT inhibitor FK866. This suggests that the MDR1/ABCB1 mechanism may regulate the resistance of anticancer NAMPT inhibitor FK866.

Effect of piceatannol-rich passion fruit seed extract on human glyoxalase I-mediated cancer cell growth

Passion fruit seed extract (PFSE), a product rich in stilbenes such as piceatannol and scirpusin B, has various physiological effects. It is unclear whether PFSE and its stilbene derivatives inhibit cancer cell proliferation via human glyoxalase I (GLO I), the rate-limiting enzyme for detoxification of methylglyoxal. We examined the anticancer effects of PFSE in two types of human cancer cell lines with different GLO I expression levels, NCI–H522 cells (highly-expressed GLO I) and HCT116 cells (lowly-expressed GLO I). PFSE and its stilbenes inhibited GLO I activity. In addition, PFSE and its stilbenes supressed the cancer cell proliferation of NCI–H522 cells more than HCT116 cells. These observations suggest that PFSE can provide a novel anticancer strategy for prevention and treatment.

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Piceatannol, and scirpusin B inhibited GLO I activity.

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Passion fruit seed extract suppressed proliferation and colony formation of NCI–H522 cells.

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Passion fruit seed extract and piceatannol could exert anticancer activity via GLO I inhibition.

Genomic and tumor biological aspects of the anticancer nicotinamide phosphoribosyltransferase inhibitor FK866 in resistant human colorectal cancer cells

Cancer cells' resistance to drugs remains an important problem affecting cancer treatment strategies. We previously studied the nicotinamide phosphoribosyltransferase (NAMPT) inhibitor FK866's resistance mechanisms in the human colorectal cancer HCT116 cells. We established an acquired FK866-resistant cell line, HCT116R^FK866. In this study, we investigated gene mutations in parental HCT116 and HCT116R^FK866 cells using exome sequencing technology. The results indicated cluster genes related to NAD⁺ biosynthesis (including NAMPT), DNA repair, and ATP-binding cassette transporters were differentially altered in these cells. Interestingly, HCT116R^FK866 cells, which are resistant to other class NAMPT inhibitors, were more sensitive to the anticancer 5-fluorouracil and cisplatin and γ-ray irradiation compared to parental HCT116 cells. This higher sensitivity appears to cause a genetic change in the identified gene clusters by resistance to the NAMPT inhibitor FK866. Collectively, these novel findings provide a better understanding of anticancer candidate NAMPT inhibitors with regard to resistance mechanisms and cancer chemotherapy strategies.

Topography Influences Adherent Cell Regulation of Osteoclastogenesis

The importance of osteoclast-mediated bone resorption in the process of osseointegration has not been widely considered. In this study, cell culture was used to investigate the hypothesis that the function of implant-adherent bone marrow stromal cells (BMSCs) in osteoclastogenesis is influenced by surface topography. BMSCs isolated from femur and tibia of Sprague-Dawley rats were seeded onto 3 types of titanium surfaces (smooth, micro, and nano) and a control surface (tissue culture plastic) with or without osteogenic supplements. After 3 to 14 d, conditioned medium (CM) was collected. Subsequently, rat bone marrow-derived macrophages (BMMs) were cultured in media supplemented with soluble receptor activator of NF-κB ligand (RANKL) and macrophage colony-stimulating factor (M-CSF) as well as BMSC CM from each of the 4 surfaces. Gene expression levels of soluble RANKL, osteoprotegerin, tumor necrosis factor α, and M-CSF in cultured BMSCs at different time points were measured by real-time polymerase chain reaction. The number of differentiated osteoclastic cells was determined after tartrate-resistant acid phosphatase staining. Analysis of variance and t test were used for statistical analysis. The expression of prominent osteoclast-promoting factors tumor necrosis factor α and M-CSF was increased by BMSCs cultured on both micro- and nanoscale titanium topographies (P < 0.01). BMSC CM contained a heat-labile factor that increased BMMs osteoclastogenesis. CM from both micro- and nanoscale surface-adherent BMSCs increased the osteoclast number (P < 0.01). Difference in surface topography altered BMSC phenotype and influenced BMM osteoclastogenesis. Local signaling by implant-adherent cells at the implant-bone interface may indirectly control osteoclastogenesis and bone accrual around endosseous implants.

Diagnostic laparoscopy identifies a peritoneal adenomatoid-like mesothelioma masquerading as ovarian cancer: a case report

The authors report a rare case of peritoneal adenomatoid mesothelioma in a woman with no history of asbestos exposure. A 61-year-old woman was originally suspected of having a bilateral ovarian tumor based on chest radiography and magnetic resonance imaging (MRI). Upon referral to our hospital, the presence of two solid masses was confirmed by enhanced MRI and 18F-fluorodeoxyglucose positron-emission tomography/computed tomography (18F-FDG-PET/CT). Physical examination was normal, as were serum concentrations of the tumor markers CA 19-9, CA 125, and CEA. Laparoscopic surgery showed a right ovarian tumor and laparoscopic right salpingo-oophorectomy and adhesiotomy were performed. Two months later, the patient underwent laparoscopic segmental resection of the sigmoid colon, with histological analysis identifying an adenomatoid-like tumor. The final diagnosis was peritoneal adenomatoid-like mesothelioma with invasion of the right ovary. This case report demonstrates that imaging techniques must be coupled with laparoscopic surgery for an accurate diagnosis of peritoneal mesothelioma.

Pramipexole Safely Replaces Ergot Dopamine Agonists with either Rapid or Slow Switching

This prospective, open-label, multicentre study examined the efficacy and safety of rapidly (overnight) or slowly (after 2 weeks of concomitant usage) switching patients with Parkinson's disease (PD) from conventional ergot dopamine agonists (DAs) to the non-ergot DA, pramipexole. Fifty-nine early-to-advanced PD patients with motor symptoms that were inadequately controlled by ergot DAs were enrolled. Patients were switched from ergot derivatives to pramipexole and evaluated every 2 weeks for 12 weeks by Hoehn and Yahr staging, Unified Parkinson's Disease Rating Scale (UPDRS) and a modified Epworth Sleepiness Scale (mESS). The UPDRS III subscores and total UPDRS scores significantly improved, independent of switching method. Adverse events, all of which were mild, occurred in 29.2% of patients. No sudden onset of excessive daytime sleepiness or significant worsening in mESS was seen. Switching patients with PD from ergot DA to pramipexole, using either a slow or rapid switching method, appeared to be well tolerated and effective, although further dose adjustment may be necessary in some patients after the switch.

Treatment of steroid-resistant idiopathic thrombocytopenic purpura in pregnancy with repeated high-dose intravenous immunoglobulin

High-dose intravenous immunoglobulin (HD-IVIG) has temporary but reliable efficacy in idiopathic thrombocytopenic purpura (ITP). HD-IVIG has been described as the representative management in pregnant cases of refractory to corticosteroid or immunosuppressants. There have been few cases treated with repeated HD-IVIG to sustain pregnancy from the early phase of pregnancy. This case report describes a pregnant case of steroid-refractory ITP, treated with six times repeated HD-IVIG, resulting in the successful delivery of a healthy newborn with a normal platelet count. No adverse effects were observed.

Occlusal and TMJ loads in subjects with experimentally shortened dental arches

To determine whether shortened dental arches (SDAs) cause functional overloading of the teeth and the temporomandibular joints, which has been implicated in periodontal diseases and temporomandibular disorders, we investigated the influences of SDA on occlusal and joint loads. Bite force and masticatory muscle electromyograms were recorded in five dentate subjects who clenched maximally on intra-oral appliances, creating symmetrical SDAs experimentally. Muscular forces estimated from the recorded electromyograms were fed into a finite element jaw model for calculating bite forces and joint loads. Comparison between the measured and the calculated bite forces ensured that the joint loads were representative. The bite force on each tooth increased with missing molar occlusions, while joint loads decreased. The bite force per root surface area was always greatest on the most posterior tooth, and these values were most constant. The findings provide no evidence that SDA causes overloading of the joints and the teeth, which suggests that neuromuscular regulatory systems are controlling maximum clenching strength under various occlusal conditions.

External genitalia formation: role of fibroblast growth factor, retinoic acid signaling, and distal urethral epithelium

The process of fetal external genitalia development might be divided into two processes. The first process accomplishes the initial outgrowth of the anlage, genital tubercle (GT). Previous analysis suggests that the distal urethral epithelium (DUE) of the GT, the Fgf8-expressing region, regulates the outgrowth of the GT. The second process eventually generates the sexually dimorphic development of the external genitalia, which is dependent on the action of steroid hormones. Several key genes, for example, RARs, RXRs, RALDH2, and CYP26, were dynamically expressed during GT development. The teratogenic dose of RA at 9.0 d.p.c. induced a drastic malformation of the urethral plate during GT formation, but did not show gross abnormalities in its outgrowth. In RA-treated embryos, Fgf8 expression was still detected in the distal GT regions. Possible regulatory roles of the FGF and RA signaling systems in external genitalia formation are discussed.

Orthotopic intestinal transplantation using the cuff method in rats: a histopathological evaluation of the anastomosis

Segmental small intestine transplantation (SIT) in rats, using a cuff technique, has achieved a high success rate. However, there have been few reports on the influence of the foreign body reaction to polyethylene cuff on vessel anastomoses and graft after SIT. This study involves the histopathological examination of the site of cuff anastomosis and grafts in the short- and long-term survival of segmental SIT. The data obtained from the suture anastomosis model also served as a control. One week after heterotopic segmental SIT using the cuff technique, orthotopic continuations were carried out in syngeneic combination. Twenty-five of 30 rats surviving >200 days (83.3%) were examined for vessel anastomosis. All arterial anastomoses were patent, but the portovenous anastomoses in 10 grafts (33%) were totally occluded and were associated with the formation of collateral vessels. Histopathological examination demonstrated good patency of the artery and vein anastomotic site in the short term, but granulation, fibrosis, and neovascularization at the anastomosis site surrounding the cuffs in the long-surviving group. However, the grafts appeared to be intact, with normal features of the villi. On the contrary, the site of the sutured anastomosis in the long-survival rats showed no inflammatory reaction. Although a polyethylene cuff caused foreign body reaction, the graft blood supplies were maintained by collateral vessels. Considering the low mortality and high success rate, polyethylene cuff is good for short-term study and an alternative method for long-term SIT experiments.

[Successful management of a patient who developed intra-operative pulmonary tumor embolism]

A 68-year-old female with retroperitoneal tumor extending into the inferior vena cava (IVC) developed massive pulmonary tumor embolism during removal of the tumor. Because of her unstable hemodynamics, emergency pulmonary embolectomy under cardiopulmonary bypass was performed. Successful management of her intra- and post-operative persistent right heart failure led to a satisfactory postoperative course without serious neurological complications. In peri-operative management of a patient with an extended tumor into IVC, prevention of the embolism, detection of the pulmonary embolism and treatment of intra- and post-operative right heart failure are important.

[Notes about two paintings in the Francis A. Countway Library of Medicine]

Two interesting mural-sized oil paintings hang in the Francis A. Countway Library of Medicine in Boston. One is "The First Operation Under Ether" painted by Robert C. Hinckley in the nineteenth century, and the other is "The First Successful Kidney Transplantation" painted by Joel Babb in 1996. The theme of the former is the first operation with ether performed publicly on October 16, 1846, at the Massachusetts General Hospital. That of the latter is the first successful renal transplantation between identical twins performed at the Peter Bent Brigham Hospital on December 23, 1954. "The First Operation Under Ether" was recreated by the painter, Robert Hinckley, who gathered information by himself about the event, which had occurred over three decades previously in his hometown. He seemed to have exercised some degree of artistic license in recreating the scene. On the other hand, "The First Successful Kidney Transplantation" was planned by the three doctors who were themselves involved in the memorable operation. The painter, Joel Babb, began to recreate the scene after he had been handed some sketches and photos of the event and several photos of the participants. In this case, it seems that authenticity was the main consideration.

Identification of a silent pituitary somatotropic adenoma based on a paradoxic response of growth hormone on a thyrotropin-releasing hormone or gonadotropin-releasing hormone provocation test

Preoperative endocrinologic identification and surgical removal of a silent somatotropic adenoma among patients with either amenorrhea or galactorrhea, or both, are beneficial for the restoration of menstruation and ovulation. Paradoxic rises of serum growth hormone in either a thyrotropin-releasing hormone or a gonadotropin-releasing hormone provocation test and high serum growth hormone levels were noted in the 3 patients with a silent somatotropic adenoma.

[Pulmonary embolism during laparoscopic cholecystectomy detected by sudden decrease in end-tidal carbon dioxide pressure]

We report a case of intraoperative pulmonary embolism, detected by a sudden decrease in end-tidal carbon dioxide pressure (PETCO2). The patient was a 56-year-old female without any history of pulmonary disease. The patient was intubated and ventilated manually during the operation under anesthesia with sevoflurane, nitrous oxide, and vecuronium. The percutaneous oxygen saturation (SpO2) and PETCO2 were monitored continuously. Twenty minutes after starting the laparoscopic procedure, PETCO2 decreased suddenly from values between 34 and 38 mmHg to 24 mmHg, and SpO2 decreased from 99% to 95%. Nitrous oxide was discontinued. Removal of the drape revealed profound subcutaneous emphysema. Postoperative pulmonary scanning revealed areas with reduced pulmonary perfusion (Fig. 2). An intravenous bolus of heparin (3000 IU) was given immediately, followed by 10,000 IU heparin over the next 24 hours. The patient was discharged on the fifteenth postoperative day without any sequelae. Although monitoring pulmonary arterial pressure is generally considered a more reliable method for the early detection of pulmonary embolism, an invasive monitoring procedure, such as the insertion of a Swan-Ganz catheter, is usually not indicated in laparoscopic surgery. For the early detection of pulmonary embolism, we therefore recommend the continuous monitoring of PETCO2 during laparoscopic surgery.

A potent, long-acting, orally active (2R)-2-[(1R)-3, 3-difluorocyclopentyl]-2-hydroxy-2-phenylacetamide: novel muscarinic M(3) receptor antagonist with high selectivity for M(3) over M(2) receptors

A novel series of (2R)-2-[(1R)-3, 3-difluorocyclopentyl]-2-hydroxy-2-phenylacetamides was designed and synthesized based on the structure and biological profiles of an active metabolite 2 of our prototype muscarinic M(3) receptor selective antagonist 1, to develop a potent, long-acting, orally active M(3) antagonist for the treatment of urinary tract disorders, irritable bowel syndrome, and respiratory disorders. Investigation of (2R)-2-[(1R)-3, 3-difluorocyclopentyl]-2-hydroxy-2-phenylacetamides containing a phenyl or heterocyclic ring as the piperidinyl side chain in place of the 4-methyl-3-pentenyl moiety of 15a revealed that this acid moiety was a versatile template for improving the selectivity for M(3) over M(2) receptors in comparison with the corresponding cyclopentylphenylacetic acid group. However, since the in vitro metabolic stability of these analogues was insufficient compared with that of 2, further derivatization was performed by introducing an appropriate hydrophilic group into the phenyl or 2-pyridyl ring. Thus, the 1-(6-aminopyridin-2-ylmethyl)piperidine analogue 15y exhibiting 190-fold selectivity for M(3) receptors (K(i) = 2.8 nM) over M(2) receptors (K(i) = 530 nM) in a human binding assay and good in vitro metabolic stability in dog and human hepatic microsomes was identified. This compound has excellent oral activity at 4 h after oral dosing (1 mg/kg), inhibiting methacholine-induced bronchoconstriction in dogs, and may be useful in clinical situations in which M(3) over M(2) selectivity is desirable.

Dietary conjugated linoleic acid increases immunoglobulin productivity of Sprague-Dawley rat spleen lymphocytes

The dietary effects of conjugated linoleic acid (CLA) on Ig production of Sprague-Dawley rats were examined at various doses such as 0 (control), 0.05, 0.10, 0.25, and 0.50%. CLA increased IgG and IgM production of spleen lymphocytes in a dose-dependent manner, and these levels reached a plateau at 0.25%. IgA production was not detected in the control group, while it was detected in all CLA-fed groups and IgA productivity of spleen lymphocytes increased in a dose-dependent manner at the doses from 0.05 to 0.50%. Dietary CLA did not affect serum Ig levels. The major fatty acid composition of spleen lymphocytes was not affected by dietary CLA, which itself was hardly incorporated into the cells. In an in vitro assay, the effects of CLA and its oxidative derivatives, furan type fatty acids, on Ig productivity were also examined. As a result, 100 microM CLA suppressed Ig production of spleen lymphocytes and the degree was as follows IgA > IgG > IgM. Each CLA isomer and the furan type fatty acids also suppressed Ig production but the degree was weaker than the mixture of CLA isomers. In this result, dietary CLA increased Ig productivity of spleen lymphocytes in vivo.

Acute reduction of serum leptin level by dietary conjugated linoleic acid in Sprague-Dawley rats

The purpose of this study was to clarify the effect of conjugated linoleic acid on lipid accumulation in adipose tissue. Sprague-Dawley rats were fed a diet containing 2% conjugated linoleic acid for 1, 3, 6, and 12 weeks. In rats fed 2% conjugated linoleic acid, the weight of perirenal white adipose tissue was comparable with that of rats fed a conjugated linoleic acid-free diet. For fatty acid composition of perirenal white adipose tissue, both 16:1/16:0 and 18:1/18:0 ratios were significantly lower in the conjugated linoleic acid-fed group than the control group. Although there was no remarkable difference in serum triglyceride, total cholesterol, and phospholipid levels between dietary groups, serum leptin level was significantly lower than the control group, and lipid content in the perirenal white adipose tissue exerted a tendency toward low compared to the control value at 1-week feeding. On the other hand, leptin level in perirenal white adipose tissue was significantly lower in the conjugated linoleic acid-fed group than the control group at 12-week feeding. In conclusion, these observations suggest dietary conjugated linoleic acid is an acute reducer of serum leptin level. This may afford an explanation of the mechanism of anti-obesity effect in conjugated linoleic acid.

[Perioperative management of a patient with a history of over-the-counter analgesic abuse for 20 years]

A 67-year-old man, complicated with liver cirrhosis, diabetes mellitus, and ischemic heart disease, was scheduled for gastrectomy. He had been taking an over-the-counter (OTC) analgesic containing acetaminophen, ethenzamid and caffeine for 20 years, and refused to stop taking it preoperatively. He received general anesthesia with isoflurane, supplemented with fentanyl and midazolam. Muscle relaxation was obtained with vecuronium. Isosorbide was infused continuously to prevent myocardial ischemia. The anesthetic course was uneventful. Postoperatively, the patient experienced no difficulty in abstaining from taking the OTC analgesic. The patient's perioperative course indicates that he was not dependent on this OTC drug, but he needed this medication only to ameliorate his preoperative anxiety or depressive mood.

Thrombin stimulates pertussis toxin-sensitive and -insensitive GTPase activities and ADP-ribosylation of G(i) in human neuroblastoma SH-EP

Kinetic interaction between thrombin receptor and G proteins was investigated in human epithelial neuroblastoma cell line, SH-EP. In these cells, both alpha-thrombin and SFLLRNP (one-letter amino-acid code) stimulated GTPase activity and enhanced cholera toxin-catalyzed ADP-ribosylation of G(i2) in a concentration-dependent manner. Basal GTPase activity was attenuated by pertussis toxin treatment by 35%, however, agonist stimulation was preserved significantly. These results together indicated that thrombin receptor simultaneously activates G(i2) and PTX-insensitive G protein(s).

Discovery of a muscarinic M3 receptor antagonist with high selectivity for M3 over M2 receptors among 2-[(1S,3S)-3-sulfonylaminocyclopentyl]phenylacetamide derivatives

In the course of developing a metabolically stable M3 receptor antagonist from the prototype antagonist, J-104129 (1), introduction of certain substituents into the cyclopentane ring of 1 was found to be effective not only in improving metabolic stability but also in greatly enhancing the subtype selectivity. Among the cyclopentane analogues, sulfonamide derivatives (10f) and (10g) displayed 160- and 310-fold selectivity for M3 over M2 receptors, and both were significantly more selective than the prototype antagonist (120-fold). Subsequent derivatization of the sulfonamide series led to the highly selective M3 receptor antagonists (10h, 10i and 10j) with >490-fold selectivity for M3 over M2 receptors. Among them, p-nitrophenylsulfonamide (J-107320, 10h) exhibited 1100-fold selectivity for M3 receptors (Ki = 2.5 nM) over M2 receptors (Ki = 2800 nM) in the human muscarinic receptor binding assay using [3H]-NMS as a radio ligand.

J-104129, a novel muscarinic M3 receptor antagonist with high selectivity for M3 over M2 receptors

A new class of 4-acetamidopiperidine derivatives has been synthesized and investigated for human muscarinic receptor subtype selectivity. Introduction of a hydrocarbon chain of appropriate length into the piperidine nitrogen of the racemic N-(piperidin-4-yl)-2-cyclobutyl-2-hydroxy-2-phenylacetamide platform conferred up to 70-fold selectivity for human muscarinic M3 receptors over M2 receptors. Subsequent synthetic derivatizations resulted in highly potent M3 receptor antagonists with selectivity greater than two orders of magnitude for M3 over M2 receptors, from which the analogue 4r was selected. Preparation of both enantiomers of 4r led to the identification of (2R)-N-[1-(4-methyl-3-pentenyl)piperidin-4-yl]-2-cyclopentyl-2-hyd roxy-2-phenylacetamide (J-104129, (R)-4r), which exhibited 120-fold selectivity for M3 receptors (Ki = 4.2 nM) over M2 receptors (Ki = 490 nM). In isolated rat trachea, (R)-4r potently and specifically antagonized acetylcholine (ACh)-induced responses with a K(B) value of 3.3 nM. The highly subtype-selective profile was also seen in isolated rat tissue assays (50-fold) and in anesthetized rats (> 250-fold). Oral administration of J-104129 ((R)-4r) antagonized ACh-induced bronchoconstriction with an ED50 value of 0.58 mg/kg in rats. Thus, J-104129 ((R)-4r) may effectively facilitate bronchodilation in the treatment of obstructive airway disease.

Pituitary somatotroph adenoma producing growth hormone (GH)-releasing hormone (GHRH) with an elevated plasma GHRH concentration: a model case for autocrine and paracrine regulation of GH secretion by GHRH

An acromegalic patient with a pituitary somatotroph adenoma associated with an extremely elevated plasma GHRH concentration is presented. The preoperatively high concentration of plasma GHRH returned to the normal level after successful removal of the adenoma. GHRH production and GHRH gene expression were confirmed in the adenoma by studies including immunohistochemistry and in situ hybridization. Expression of GHRH receptor messenger ribonucleic acid was verified by in situ hybridization. Immunohistochemical double staining for GH and GHRH revealed their colocalization in single adenoma cells. These findings confirmed the autocrine or paracrine regulation of GH production by endogenous GHRH from the adenoma cells. GHRH synthesis in the pituitary gland has recently been demonstrated, however, there have been no previous reports of a GHRH-producing pituitary somatotroph adenoma associated with an elevated plasma GHRH concentration. The existence of this GHRH-producing adenoma suggests a possible role of locally generated GHRH in the progression of somatotroph adenomas, i.e. the monoclonally established somatotroph adenomas develop further under the influence of locally produced GHRH. The demonstration of GHRH production by this somatotroph adenoma is of importance in clarifying the autocrine or paracrine regulation of GH production and the progression of human somatotroph adenomas.