Ku-band multichannel frequency comb Doppler reflectometer on the GAMMA 10/potential control and divertor simulating experiment (PDX) tandem mirror

A Ku-band (12-18 GHz) multichannel Doppler reflectometer (DR) has been developed in the GAMMA 10/potential control and divertor simulating experiment (PDX) tandem mirror device to improve the applicability of DR measurement for simultaneous monitoring of velocity of electron density turbulence at different locations. Our previous single-channel DR circuit has been replaced by the multichannel microwave system using a nonlinear transmission line based comb generator with heterodyne technique. The multichannel DR system has been installed in the central cell of GAMMA 10/PDX. Initial results of application to GAMMA 10/PDX plasma are presented, showing Doppler frequency shifts during an additional ion cyclotron resonance frequency heating and gas-puffing experiment.

99mTc-GSA scintigraphy for assessing the functional volume ratio of the future liver remnant in the routine practice of liver resection

Background

The significance of incorporating regional functional heterogeneity assessment by liver scintigraphy into the calculation of the future liver remnant has been reported. However, liver scintigraphy entails additional costs and radiation exposure. Nevertheless, studies describing when liver scintigraphy demonstrates an actual benefit over computed tomography liver volumetry are lacking. Thus, we evaluated the degree of agreement between future liver remnant % values calculated by technetium ^99mTc diethylenetriaminepentaacetic acid-galactosyl human serum albumin scintigraphy (galactosyl human serum albumin–based future liver remnant %) and those by computed tomography volumetry and investigated the practical impact of performing regional functional heterogeneity assessment.

Methods

The Bland–Altman method was used to retrospectively analyze the agreement between computed tomography– and galactosyl human serum albumin–based future liver remnant % measurements in 84 patients.

Results

In ordinary patients with a computed tomography–based future liver remnant % greater than 50%, there was a good agreement between both measurements. However, in cases with a computed tomography–based future liver remnant % less than 40%, galactosyl human serum albumin–based measurements were significantly smaller than computed tomography–based values, with 88% of these patients exhibiting a galactosyl human serum albumin–based future liver remnant % less than 30%. After portal vein embolization, galactosyl human serum albumin–based measurements were primarily greater than or in agreement with computed tomography–based values, even in cases with a computed tomography–based future liver remnant % less than 40%.

Conclusion

Adding ^99mTc diethylenetriaminepentaacetic acid-galactosyl human serum albumin scintigraphy to computed tomography liver volumetry is advised when deciding on hepatectomy in patients with a computed tomography–based future liver remnant % less than 50%. If the computed tomography–based future liver remnant % is smaller than 40%, it is strongly recommended to check future liver remnant % by ^99mTc diethylenetriaminepentaacetic acid-galactosyl human serum albumin scintigraphy. In other cases, computed tomography–based future liver remnant % calculation alone can be regarded as the gold standard of safe hepatectomy.

Evaluation of 3-week-old layer chicks intratracheally challenged with Salmonella isolates from serogroup c1 (O:6,7) and Salmonella Enteritidis

With the exception to Salmonella enterica serotype Typhimurium and S. Enteritidis (serogroups B [O:4] and D [O:9], respectively), there have been very few studies conducted on the respiratory tract as route of infection in chickens with salmonellas from serogroup C1 (O:6,7). Therefore, the purpose of this present study was to determine the potential organ invasion by Salmonella enterica serotype Potsdam (SP), S. Mbandaka (SM), and S. Infantis (SI) from serogroup C1 (O:6,7) and compare their characteristics with those of S. Enteritidis (SE) on intratracheally (IT) challenged 3-week-old layer chicks. A total of 360 one-day-old White Leghorn layer chicks were acquired from a commercial hatchery and randomly assigned into four treatment groups (SP, SM, SI, and SE, respectively), consisting of three independent trials. Chicks were grown up to 21 days (3 weeks) and IT-challenged thereafter with 10⁶ CFU of respective salmonella organisms per group (n = 30). Chicks (n = 5) were humanely sacrificed every 24 h for 6 days post-IT infection and organs such as lung, heart, liver, spleen, kidney and caecal content were cultured for salmonella. All treatment groups exhibited colonization of lungs and caecal contents at 1 d (P = 0.475) and 4 d (P = 0.696) post-IT infection, respectively. There was no isolation of SP, SM, and SI in heart, liver, spleen, and kidney. In contrast, SE was obtained from heart, liver, and spleen of IT-infected chicks. The findings of this study contribute to a better understanding of the importance of the respiratory route in salmonella infection in poultry.

Risk factors for residual mitral regurgitation after aortic valve replacement in patients with severe aortic valve stenosis and moderate mitral regurgitation

OBJECTIVES

While it was reported that patients with residual moderate mitral regurgitation (MR) after surgical aortic valve replacement (SAVR) had a poorer prognosis than those without it, the risk factors for residual MR have not been fully elucidated. The aim of the study was to evaluate risk factors for residual MR after SAVR.

METHODS

Of the 222 patients who underwent isolated SAVR from 2001 to 2018, 33 (11 men; age: 74 ± 7 years) had functional moderate MR before surgery. The risk factors for residual MR were evaluated by comparing patients with residual moderate MR (n = 11, 33%) with those who exhibited improved post-surgery MR (n = 22, 67%).

RESULTS

The left atrial diameter was significantly larger in the residual MR group (51 ± 7 mm) than in the improved MR group (46 ± 5 mm; P = 0.049). The mean pressure gradient at the aortic valve was significantly smaller in the residual MR group (52 ± 18 mmHg) than in the improved MR group (69 ± 22 mmHg; P = 0.043). A ratio of left atrial diameter (mm) and mean aortic valve pressure gradient (mmHg) greater than 0.9 predicted residual MR with a sensitivity of 70% and a specificity of 74% (area under the ROC curve: 0.779; P = 0.015).

CONCLUSIONS

In patients with severe aortic valve stenosis and moderate MR, a high ratio of preoperative left atrial diameter and mean aortic valve pressure gradient would be a parameter predicting residual moderate MR post-SAVR.

Re-do mitral valve replacement for a bioprosthetic valve with central transvalvular leakage in a patient with ischemic cardiomyopathy: a case report

Transvalvular leakage (TVL) of a prosthetic heart valve is not negligible regurgitant flow in patients with critically low contractile function. Although the opening function of prosthetic valves has been reported, its closing function is not well understood. A man in his 70 s had a history of mitral valve replacement (MVR) with a Magna Mitral® valve for ischemic mitral valve regurgitation. He presented with dyspnea 2 years postoperatively. Echocardiography showed moderate TVL. The pulmonary capillary wedge pressure and cardiac index were 37 mmHg and 1.65 L/min/m², respectively. Because we considered his TVL relevant, we performed re-do MVR with a mechanical valve and papillary muscle approximation and suspension ("papillary muscle tugging approximation"). His cardiac function improved postoperatively; he was discharged with New York Heart Association class I. For MVR in patients with critically low contractile function, prosthetic valves, such as mechanical valves, with small TVL are recommended.

Mechanical properties of a new thermally deformable mitral valve annuloplasty ring and its effects on the mitral valve

Ideally, an annuloplasty ring's shape should be changed intraoperatively if mitral valve repair is unsuccessful because of a short coaptation length or systolic anterior motion. Several post-implantation adjustable rings have been developed, but they are not freely deformable and are unsuitable for asymmetric repair of the valvular annulus. We developed a novel thermally deformable mitral annuloplasty ring to address these problems and assessed the ring's mechanical properties and its effect on the mitral valve anatomy. This ring was made of polycaprolactone. Tensile and bending tests were performed to evaluate the ring's mechanical properties. The ratio of the transverse and septal-lateral length was determined as 4:3. Using 10 pig hearts, we measured the post-deformation coaptation length and minimum distance from the coaptation to the ventricular septum, which is a factor of abnormal systolic anterior motion of the mitral valve. In the mechanical tests, the ring's yield point was greater than the deformation force of the annulus in humans. In pigs with deformation from "4:3" to "4:2", the coaptation length was significantly increased in each mitral valve part. In pigs with deformation from "4:3" to "4:4", the minimum distance from the coaptation to the ventricular septum was significantly increased. Asymmetrical ring deformation increased the coaptation length only at the deformed area. In conclusion, this new thermally deformable mitral annuloplasty ring could be "order-made" to effectively change the coaptation length in all parts of the mitral valve and the distance from the coaptation to septum post-deformation via intraoperative heating.

Characterization of Ornithobacterium rhinotracheale from commercial layer chickens in eastern Japan

From a total of 72 commercial layer and pullet farms that were monitored in the eastern Japan area, 4 farms had mild to severe respiratory disease accompanied by decreased feed intake and drop in egg production. Microbiological analysis showed that 3 of the 4 farms, particularly from Fukushima, Tochigi, and Ibaraki prefectures, were positive for Ornithobacterum rhinotracheale (ORT). Out of 65 birds examined, ORT was isolated in 21 birds (32.31%). All isolates were Gram-negative pleomorphic rods with a colony size of 0.05 mm, translucent with grayish coloration, and with butyric smell after 48 h of incubation in 10% chicken blood agar at 37°C under microaerophilic conditions. All isolates reacted positively in the p-nitrophenyl-β-d-galactopyranoside test within 3 h and were positive in cytochrome oxidase tests with an API 20NE identification system biocode of 0-0-2-0-0-0-4. An agar gel precipitation test showed that all isolates were serotype-A. All strains were positive in PCR by yielding a 784 bp amplicon of the 16S rRNA gene. All strains were resistant to amikacin, colistin, gentamicin, kanamycin, neomycin, polymyxin b, streptomycin, and sulfamethoxazole trimethoprim and susceptible to amoxicillin clavulanic acid, ampicillin, doxycycline, spectinomycin, and tetracycline. This study is the first characterization of ORT from commercial layer chickens in eastern Japan.

Detection of synchronized burst firing in cultured human induced pluripotent stem cell-derived neurons using a 4-step method

Human induced pluripotent stem cell-derived neurons are promising for use in toxicity evaluations in nonclinical studies. The multi-electrode array (MEA) assay is used in such evaluation systems because it can measure the electrophysiological function of a neural network noninvasively and with high throughput. Synchronized burst firing (SBF) is the main analytic parameter of pharmacological effects in MEA data, but an accurate method for detecting SBFs has not been established. In this study, we present a 4-step method that accurately detects a target SBF confirmed by the researcher's interpretation of a raster plot. This method calculates one set parameter per step, in the following order: the inter-spike interval (ISI), the number of spikes in an SBF, the inter-SBF interval, and the number of spikes in an SBF again. We found that the 4-step method is advantageous over the conventional method because it determines the preferable duration of an SBF, accurately distinguishes continuous SBFs, detects weak SBFs, and avoids false detection of SBFs. We found also that pharmacological evaluations involving SBF analysis may differ depending on whether the 4-step or conventional threshold method is used. This 4-step method may contribute to improving the accuracy of drug toxicity and efficacy evaluations using human induced pluripotent stem cell-derived neurons.

Feasibility and limitations of mitral valve repair, with or without left ventricular reconstruction in non-ischemic dilated cardiomyopathy

BACKGROUND

Although non-transplant surgical interventions for non-ischemic dilated cardiomyopathy (NIDCM) are relatively effective, their feasibility and limitations have not been fully elucidated. The aim of this study was to define the feasibility and limitations of mitral valve repair, with or without surgical ventricular reconstruction for patients with NIDCM in terms of postoperative low cardiac output syndrome (LOS).

METHODS

Twenty non-transplant candidates (aged 57±13 years) with NIDCM and significant mitral regurgitation had undergone mitral valve repair combined with submitral procedures. Using a 72-mL plastic ellipsoidal sizer, left ventricular reconstruction was performed concomitantly in 14/20 (70%) patients with extremely large ventricles. Total stroke volume, deceleration time of early trans-mitral flow wave, and the slope (Mw) in the preload recruitable stroke-work relationship were assessed using transthoracic echocardiography. LOS was defined as in-hospital death due to heart failure or a cardiac index less than 2.2L/min/m² before discharge.

RESULTS

There were three in-hospital deaths and four patients with postoperative cardiac index less than 2.2L/min/m² [n=7 (35%), LOS group]. Preoperative total stroke volume, deceleration time, and the Mw were significantly lower in the LOS group compared to those in the non-LOS group; the predicted cut-off values for LOS were 84mL/beat (p=0.008), 133ms (p=0.015), and 45ergcm^-3×10³ (p=0.036), respectively. Preoperative left ventricular ejection fraction and ventricular size could not predict postoperative LOS. The one-year survival rate was 0% in the LOS group and 84% in the non-LOS group (p<0.001).

CONCLUSIONS

Mitral valve repair, with or without left ventricular reconstruction, could be contraindicated for NIDCM patients with low total stroke volume, deceleration time, and Mw in terms of high postoperative incidence of LOS. For high-risk patients, other therapeutic strategies might be necessary.

Decreased gene expression of fatty acid binding protein 3 in the atrium of patients with new onset of atrial fibrillation in cardiac perioperative phase

BACKGROUND

Post-operative atrial fibrillation (POAF) frequently occurs after cardiac surgery. However, the mechanisms of POAF have not been fully elucidated. We aimed to examine whether pre-operative atrial gene expression related to cardiac metabolism is changed in patients with POAF.

METHODS

Right atrial tissue was obtained during surgery from 38 patients who underwent cardiac surgery from 2013 to 2015. Atrial expression levels were determined by reverse transcription polymerase chain reaction for the following genes: glucose transporter type 4, peroxisome proliferator-activated receptor-α, fatty acid translocase, carnitine palmitoyltransferase 1B, and fatty acid binding protein 3 (FABP3). To investigate fatty acid β-oxidation and tricarboxylic acid cycle capacities in the mitochondria, β-hydroxyacyl CoA dehydrogenase and citrate synthase activity levels were spectrophotometrically determined.

RESULTS

POAF within 7 days after surgery was observed in 18 (47%) patients. POAF patients were significantly older, had a larger left atrial diameter, and had reduced expression of FABP3, a fatty acids transport gene in the cytosol, compared to those in the non-POAF group. Reduced FABP3 expression predicted POAF independent of age and atrial size. In contrast, fatty acid β-oxidation enzymatic activity was comparable between the groups.

CONCLUSIONS

FABP3 gene expression in the atrium was reduced in patients with POAF. These findings suggest a potential link between altered fatty acid transport in the atrium and increased AF onset after cardiac surgery.

Comprehensive molecular exploration identified promoter DNA methylation of the CRBP1 gene as a determinant of radiation sensitivity in rectal cancer

BACKGROUND

Neoadjuvant chemoradiotherapy (NCRT) for advanced rectal cancer (RC) is a well-evidenced therapy; however, some RC patients have no therapeutic response. Patient selection for NCRT so that non-responsive patients are excluded has been subjective. To date, no molecular markers indicating radiation sensitivity have been reported.

METHODS

We irradiated six colorectal cancer (CRC) cell lines and identified HCT116 cells as radiation-sensitive and HCT15 and DLD-1 cells as radiation resistant. Using a microarray, we selected candidate radiation sensitivity marker genes by choosing genes whose expression was consistent with a radiation-resistant or sensitive cell phenotype.

RESULTS

Among candidate genes, cellular retinol binding protein 1 (CRBP1) was of particular interest because it was not only induced in HCT116 cells by tentative 10 Gy radiation treatments, but also its expression was increased in HCT116-derived radiation-resistant cells vs parental cells. Forced expression of CRBP1 decreased the viability of both HCT15 and DLD-1 cells in response to radiation therapy. We also confirmed that CRBP1 was epigenetically silenced by hypermethylation of its promoter DNA, and that the quantitative methylation value of CRBP1 significantly correlated with histological response in RC patients with NCRT (P=0.031).

CONCLUSIONS

Our study identified CRBP1 as a radiation-sensitive predictor in RC.

The clinical significance of cysteine dioxygenase type 1 methylation in Barrett esophagus adenocarcinoma

Methylation of cysteine dioxygenase type 1 (CDO1) gene, a tumor suppressor gene, has been studied in various cancers; however, there is no information regarding Barrett esophagus cancer. In this study, the clinical significance of CDO1 methylation in Barrett esophagus adenocarcinoma (BEA) was clarified. CDO1 gene promoter methylation was analyzed for DNA from the patient's specimens using quantitative methylation-specific polymerase chain reaction. Thirty-eight BEA patients who underwent resection were identified between 2000 and 2014. Hypermethylation of CDO1 gene was demonstrated to be frequently recognized even at early stage in BEA by quantitative methylation-specific polymerase chain reaction. In BEA, there is a robust prognostic difference between stage I and stage II/III/IV with regard to 5-year relapse-free survival (P = 0.0016) and 5-year overall survival (P = 0.0024), and the tumor size separated by 7 cm was also a prognostic factor. There was significant difference in CDO1 gene methylation according to the tumor size (P = 0.036). BEA patients with CDO1 gene methylation were shown marginally significantly poorer prognosis (P = 0.054) than otherwise patients. In conclusion, higher CDO1 gene methylation was seen in BEA at earlier stage than in squamous cell carcinoma, and it may account for aggressive phenotype of BEA.

Induction of long-term potentiation and depression phenomena in human induced pluripotent stem cell-derived cortical neurons

Plasticity such as long-term potentiation (LTP) and long-term potentiation depression (LTD) in neuronal networks has been analyzed using in vitro and in vivo techniques in simple animals to understand learning, memory, and development in brain function. Human induced pluripotent stem cell (hiPSC)-derived neurons may be effectively used for understanding the plasticity mechanism in human neuronal networks, thereby elucidating disease mechanisms and drug discoveries. In this study, we attempted the induction of LTP and LTD phenomena in a cultured hiPSC-derived cerebral cortical neuronal network using multi-electrode array (MEA) systems. High-frequency stimulation (HFS) produced a potentiated and depressed transmission in a neuronal circuit for 1 h in the evoked responses by test stimulus. The cross-correlation of responses revealed that spike patterns with specific timing were generated during LTP induction and disappeared during LTD induction and that the hiPSC-derived cortical neuronal network has the potential to repeatedly express the spike pattern with a precise timing change within 0.5 ms. We also detected the phenomenon for late-phase LTP (L-LTP) like plasticity and the effects for synchronized burst firing (SBF) in spontaneous firings by HFS. In conclusion, we detected the LTP and LTD phenomena in a hiPSC-derived neuronal network as the change of spike pattern. The studies of plasticity using hiPSC-derived neurons and a MEA system may be beneficial for clarifying the functions of human neuronal circuits and for applying to drug screening.

Surgical strategy for ischemic mitral regurgitation adopting subvalvular and ventricular procedures

PURPOSE

The progression of left ventricular (LV) remodeling and subsequent mitral valve tethering impair the results of reduction annuloplasty for ischemic mitral regurgitation (MR).

METHODS

We studied 90 patients who underwent surgical repair of ischemic MR between 1999 and 2013 according to our surgical strategy adding submitral and ventricular procedures to annuloplasty as follows: annuloplasty alone (stage 1, n = 30), additional papillary muscle approximation (PMA) for progression of tethering (stage 2, n = 26), and additional left ventriculoplasty with PMA for progression of LV remodeling and tethering (stage 3, n = 34).

RESULTS

The preoperative New York Heart Association (NYHA) functional classes (2.5 ± 0.7, 3.1 ± 0.7 and 3.3 ± 0.7 for stages 1, 2 and 3, respectively, P <0.001), LV end-diastolic diameters (56 ± 7 mm, 66 ± 5 mm and 70 ± 7 mm, P <0.001), and LV ejection fractions (45 ± 12%, 32 ± 9% and 27 ± 9%, P <0.001) significantly differed among the stages. In contrast, the MR grades did not significantly differ (2.9 ± 0.8, 3.0 ± 1.0, and 2.9 ± 1.1, respectively; P = 0.93). Both the rates of cardiac-related survival and freedom from reoperation were comparable among the 3 groups (log-rank P = 0.92 and 0.58, respectively).

CONCLUSION

Additional submitral and ventricular procedures can compensate for the possible impairment of the outcomes after annuloplasty alone for ischemic MR in patients with severe LV remodeling and tethering.

Characteristics of inoperable patients with severe aortic valve stenosis -in the era of transcatheter aortic valve replacement

PURPOSE

Transcatheter aortic valve replacement (TAVR) has emerged as a therapeutic option for severe aortic valvular stenosis (AS). To determine the indication for TAVR, it is mandatory to clarify the characteristics of the patients who were judged as inoperable for conventional aortic valve replacement (cAVR).

METHODS

Of 185 patients newly diagnosed as severe AS from March 2010 to April 2011, we studied the characteristics of 61 (33%) patients (mean age, 86 ± 8 years) who were judged as inoperable.

RESULTS

Younger patients (<85 years old, n = 22) had more major comorbidities and lower left ventricular ejection fraction than older patients (≥85 years old, n = 39). Mean estimated mortality for cAVR by Japan score was 7.0% ± 7.4%. Japan score did not correlate to age and was calculated relatively low in the older age group (6.2% ± 7.0%) than the younger age group (8.3% ± 8.1%).

CONCLUSION

One thirds of severe AS patients were judged as inoperable. In advanced age patients, age itself and other factors, which are not included in the conventional scoring systems, might have contributed to the decision making not to perform cAVR by cardiologists. Further study is necessary to define risk factors except for age.

Role of prokaryotic type I and III pantothenate kinases in the coenzyme A biosynthetic pathway of Bacillus subtilis

Pantothenate kinases (CoaAs) catalyze the phosphorylation of pantothenate in the first step of the coenzyme A (CoA) biosynthetic pathway. These bacterial enzymes have been categorized into 3 types, the prokaryotic type I, II, and III CoaAs. Bacteria typically carry a single CoaA gene on their genome, but Bacillus subtilis possesses 2 proteins homologous to type I and III CoaAs, known as BsCoaA and BsCoaX, respectively. Both recombinant proteins exhibited the expected kinase activity and the characteristic properties of type I and III CoaAs, i.e., regulation by CoASH and acyl-CoAs in BsCoaA and the requirement of a monovalent cation in BsCoaX. Both gene disruptants appeared to grow in a manner similar to the wild-type strain. With the BsCoaX disruptant, the BsCoaA had the ability to completely fill the intracellular CoA pool, whereas the BsCoaA disruptant did not. These findings clearly indicate that these 2 CoaAs are employed together in the CoA biosynthetic pathway in B. subtilis and that the contribution of the type I CoaA (BsCoaA) to the formation of the intracellular CoA pool is larger than that of the type III CoaA (BsCoaX).

Identification of a distinct lineage of Cacopsylla chinensis (Hemiptera: Psyllidae) in Japan on the basis of two mitochondrial DNA sequences

Psyllids are a menacing pests of pears (Pyrus spp.) grown in temperate and subtropical regions of the world, including Taiwan and China. Pear psyllids belong to the large genus Cacopsylla (Psyllidae: Psyllinae). Among the 28 psyllid species that infest pear trees, Cacopsylla chinensis (Yang and Li, 1981) is considered the most harmful. Two psyllid outbreaks involving exotic species affected Japanese pear (Pyrus pyrifolia variety culta) orchards in the Saga Prefecture in July and November 2011. The psyllids were morphologically identical to the summer and winter forms of C. chinensis. In this study, we performed DNA sequence analysis of the mitochondrial cytochrome oxidase I-leucine tRNA-cytochrome oxidase II (COI-tRNA(Leu)-COII) and 16S rDNA regions to elucidate the phylogenetic relationships among 82 summer-form psyllids, five winter-form psyllids from several orchards in Japan, and those reported from Taiwan and China. The sequences of the COI-tRNA(LEU)-COII and 16S rDNA regions were identical among all 87 psyllids from Japan, regardless of summer/winter forms or orchards in Saga, Japan. Comparison of nucleotide sequences and phylogenetic analysis differentiated Japanese psyllids from the Taiwanese and Chinese C. chinensis isolates, with approximately 8 and 7% nucleotide difference in the COI-tRNA(LEU)-COII and 16S rDNA regions, respectively. The results suggest that C. chinensis possess a high level of genetic variability and that the psyllids responsible for the outbreak in Saga, Japan belong to a distinct lineage of C. chinensis.

Identification of pantoate kinase and phosphopantothenate synthetase from Methanospirillum hungatei

Pantothenate synthetase (PanC) and pantothenate kinase which function in the canonical coenzyme A (CoA) biosynthetic pathway cannot be found in most archaea. COG1829 and COG1701 intrinsic to archaea were proposed as the candidate proteins for producing 4'-phosphopantothenate instead, and the COG1701 protein from Methanosarcina mazei was assigned as PanC. Meanwhile, the Thermococcus kodakarensis COG1829 and COG1701 proteins were biochemically identified as novel enzymes, i.e., pantoate kinase (PoK) and phosphopantothenate synthetase (PPS). In this study, the functions of Mhun_0831 (COG1829) and Mhun_0832 (COG1701) from Methanospirillum hungatei were identified, and the recombinant enzymes were partially characterized. Plasmids simultaneously possessing the two genes encoding Mhun_0831 and Mhun_0832 complemented the poor growth of the temperature-sensitive Escherichia coli pantothenate kinase mutant ts9. The recombinant Mhun_0831 and Mhun_0832 expressed in E. coli cells exhibited PoK and PPS activities, respectively, being in accord with the functions of T. kodakarensis proteins. The PoK activity was most active at pH 8.5 and 40°C, and accepted ATP and UTP as a phosphate donor. Although CoA did not affect the PoK activity, the end product considerably accelerated the PPS activity. The homologs of both proteins are widely conserved in most archaeal genomes. Taken together, our findings indicate that archaea can synthesize CoA through the unique pathway involving PoK and PPS, in addition to the canonical one that the order Thermoplasmatales employs.