Role of Mitochondrial Lactate Dehydrogenase and Lactate Oxidation in the Intracellular Lactate Shuttle

( George A. Brooks ),( Herve Dubouchaud ),( Marcia Brown ),( James P. Sicurello ),( C. Eric Butz ) 한국스포츠정책과학원(구 한국스포츠개발원) 1999 International Journal of Applied Sports Sciences Vol.11 No.1

To evaluate the potential role of mitochondrial lactate dehydrogenase (LDH) in tissue lactate clearance and oxidation in vivo, isolated rat liver, cardiac, and skeletal muscle mitochondria were incubated with lactate, pyruvate, glutamate, and succinate. As well, a-cyano-4-hydroxycin-namate (CINN), a known monocarboxylate transport inhibitor, and oxamate, a known LDH inhibitor were used. Mitochondria readily oxidized pyruvate and lactate, with similar state 3 and 4 respiratory rates, respiratory control (state 3ystate 4), and ADPyO ratios. With lactate or pyruvate as substrates, a-cyano-4-hydroxycinnamate blocked the respira-tory response to added ADP, but the block was bypassed by addition of glutamate (complex I-linked) and succinate (complex 11 linked) substrates. Oxamate increased pyruvate (`10-40%), but blocked lanctate oxidation. Gel electrophoresis and electron microscopy indicated LDH isoenzyme distribution patterns to display tissue specificity, but the LDH isoenzyme patterns in isolated mitochondria were distinct from those in surrounding cell compartments. In heart, LDH-1 (H4) was concentrated in mitochondria whereas LDH-5 (M4) was present in both mitochondria and surrounding cytosol and organelles. LDH-5 predominated in liver but was more abundant in mitochondria than elsewhere. Because lactate exceeds cytosolic pyruvate concentration by an order of magnitude, we conclude that lactate is the predominant monocarboxylate oxidized by mitochondria in vivo. Mammalian liver and striated muscle mitochondria can oxidize exogenous lactate because of an internal LDH pool that facilitates lactate oxidation.

A CHARACTERIZATION OF PDMS PERVAPORATION MEMBRANES FOR THE REMOVAL OF TRACE ORGANIC FROM WATER

Yeon, Choong Kyun,Dickson, James M,Brook, Michael A 한국화학공학회 1996 Korean Journal of Chemical Engineering Vol.13 No.5

A new silicone pervaporation membrane for the removal of one of trace organics, 1,2-dichloroethane from water has been developed using polydimethylsiloxane (PDMS) and oligorneric silylstyrene as a crosslinking agent of PDMS. Optimal conditions for fabricating the best membrane were determined from swelling measurements and pervaporation experiments and then the membrane was characterized at different membrane thickness and operating conditions. In the pervaporation separation of 55-70 ppm of 1,2-dichloroethane aqueous mixtures, the developed membrane has flux of 2.5-330 g/(㎡·h) and selectivity of 230-1750 depending on membrane thickness, permeate pressure and operating ernperature. Water permeation through thin membrane was found to be subjected to significant desorption resistance, while the desorption resistance and thermodynamic factors as well as the concentration polarization of the organic at the boundary layer in feed can affect the organic permeation, depending on membrane thickness. Selectivity change with permeate pressure depends on membrane thickness: at small membrane thickness range, selectivity increases with permeate pressure and at large thickness region it decreases. From the Arrhenius plots of each component fluxes, the permeation activation energies were determined. Through an analysis of the permeation activation energies of each components, the desorption resistance as well as the effects of the thermodynamic factors on permeation was qualitatively characterized.

Optimized Methods for the Isolation of Arabidopsis Female Central Cells and Their Nuclei

Park, Kyunghyuk,Frost, Jennifer M.,Adair, Adam James,Kim, Dong Min,Yun, Hyein,Brooks, Janie S.,Fischer, Robert L.,Choi, Yeonhee Korean Society for Molecular and Cellular Biology 2016 Molecules and cells Vol.39 No.10

The Arabidopsis female gametophyte contains seven cells with eight haploid nuclei buried within layers of sporophytic tissue. Following double fertilization, the egg and central cells of the gametophyte develop into the embryo and endosperm of the seed, respectively. The epigenetic status of the central cell has long presented an enigma due both to its inaccessibility, and the fascinating epigenome of the endosperm, thought to have been inherited from the central cell following activity of the DEMETER demethylase enzyme, prior to fertilization. Here, we present for the first time, a method to isolate pure populations of Arabidopsis central cell nuclei. Utilizing a protocol designed to isolate leaf mesophyll protoplasts, we systematically optimized each step in order to efficiently separate central cells from the female gametophyte. We use initial manual pistil dissection followed by the derivation of central cell protoplasts, during which process the central cell emerges from the micropylar pole of the embryo sac. Then, we use a modified version of the Isolation of Nuclei TAgged in specific Cell Types (INTACT) protocol to purify central cell nuclei, resulting in a purity of 75-90% and a yield sufficient to undertake downstream molecular analyses. We find that the process is highly dependent on the health of the original plant tissue used, and the efficiency of protoplasting solution infiltration into the gametophyte. By isolating pure central cell populations, we have enabled elucidation of the physiology of this rare cell type, which in the future will provide novel insights into Arabidopsis reproduction.

Thermal conductivity of magnetically aligned carbon nanotube buckypapers and nanocomposites

Philippe Gonnet,Zhiyong Liang,Eun Sang Choi,Ravi Shankar Kadambala,Chuck Zhang,James. S. Brooks,Ben Wang,Leslie Krame 한국물리학회 2006 Current Applied Physics Vol.6 No.1

A novel technical approach has been developed to produce highly loaded and aligned SWNT (single wall nanotubes) nanocompositesby inltrating SWNT mats with a low viscosity resin solution. In-plane SWNT alignment is achieved by magnetically aligning the nano-tubes in the buckypaper under a high magnetic eld prior to the composite loading. The thermal conductivity of both magneticallyaligned buckypapers and their composites have been measured. The results were analyzed with models to explain the thermal conduc-buckypaper and nanocomposites. The thermal conductivities were found to increase linearly with temperature for both buckypapers andcomposites. The thermal conductivity improvement of the nanocomposites was found to be limited.

Malignant Nerve Sheath Tumor of the Spinal Accessory Nerve: A Unique Presentation of a Rare Tumor

Omair A. Sheikh,Ann Reaves,Francis A. Kralick,Ari Brooks,Rachel E. Musial,James Gasperino 대한신경과학회 2012 Journal of Clinical Neurology Vol.8 No.1

Background Malignant peripheral nerve sheath tumors (MPNSTs), sarcomas originating from tissues of mesenchymal origin, are rare in patients without a history of neurofibromatosis. Case Report We report a case of an MPNST of the spinal accessory nerve, unassociated with neurofibromatosis, which metastasized to the brain. The tumor, originating in the intrasternomastoid segment of the spinal accessory nerve, was removed. Two years later, the patient presented with focal neurological deficits. Radiographic findings revealed a well-defined 2.2×2.2×2.2 cm, homogeneously enhancing mass in the left parieto-occipital region of the brain surrounded by significant vasogenic edema and mass effect, culminating in a 1-cm midline shift to the right. The mass was surgically removed. The patient had nearly complete recovery of vision, speech, and memory.Conclusions To our knowledge, this is the first documented case of an MPNST arising from an extracranial segment of the spinal accessory nerve and metastasizing to the brain.

A new quantum Hall effect in the two-dimensional organic conductor, τ-(EDO-S ,S-DMEDT-TTF)2(AuBr2)1+y

Keizo Murata,Harukazu Yoshino,Tsutomu Nakanishi,Takako Konoike,James Brooks,David Graf,Charles Mielke,George C. Papavassiliou 한국물리학회 2004 Current Applied Physics Vol.4 No.5

In the two-dimensional organic conductor, τ-(EDO-S,S-DMEDT-TTF)2(AuBr2)1+ y, we have observed Shubnikov de Hass oscillations with Landau level down ton ¼ 2 in eld up to 27 T. Motivated with this result, we extended to Hall eect study in pulsed magnetic eld up to 60 T as well as in dc eld up to 45 T and found Hall resistance plateau above 40 T (n ¼ 1). Since this system consists of two two-dimensional Fermi surface pockets, and larger pocket has a large eective mass compared with the smaller one,larger Fermi pocket behaves as a reservoir for the smaller pocket to be well-separated into completely lled and completely emptyLandau levels in a certain range of temperature and magnetic eld. The interpretation of realizing the Hall plateau can beunderstood as a new mechanism for QHE, but is quite dierent neither from localization nor eld induce spin density wave state inorganic TMTSF salts.

Prevalence of Postprostatectomy Incontinence Requiring Antiincontinence Surgery After Radical Prostatectomy for Prostate Cancer: A Retrospective Population-Based Analysis

김재헌,정인갑,Yash S. Khandwala,Tina Hernandez-Boussard,James D. Brooks,Benjamin I Chung 대한배뇨장애요실금학회 2021 International Neurourology Journal Vol.25 No.3

Purpose: This study aimed to examine the prevalence of surgery for postprostatectomy incontinence (PI) following minimally invasive surgery compared to conventional open surgery for prostate cancer. Methods: This retrospective cohort study used the Florida State Ambulatory Surgery and State Inpatient Databases, 2008 to 2010, radical prostatectomy (RP) patients were identified using International Classification of Diseases (ICD)-9/10 procedure codes and among this cohort, PI was identified also using ICD-9/10 codes. Surgical approaches included minimally invasive (robotic or laparoscopic) versus open (retropubic or perineal) RP. The primary outcome was the overall prevalence of surgery for PI. The secondary outcome was the association of PI requiring anti-incontinence surgery with the surgical approach for RP. Results: Among the 13,535 patients initially included in the study (mean age, 63.3 years), 6,932 (51.2%) underwent open RP and 6,603 (49.8%) underwent minimally invasive RP. The overall prevalence of surgical procedures for PI during the observation period among the all patients who had received RP was 3.3%. The rate of PI surgery for patients receiving minimally invasive surgery was higher than that for patients receiving open surgery (4.8% vs. 3.0%; risk difference, 1.8%; 95% confidence interval, 0.3%–3.4%). The adjusted prevalence of PI surgery for patients who had undergone laparoscopic RP was higher than that for those with retropubic RP (8.6% vs. 3.7%). Conclusions: Among patients undergoing RP for prostate cancer, the prevalence of PI surgery is not negligible. Patients undergoing minimally invasive RP had higher adjusted rates for PI surgery compared to open approaches, which was attributed to high rate of PI surgery following laparoscopic approach and low rate of PI surgery following perineal approach. More studies are needed to establish strategies to reduce the rate of PI surgery after RP.

Optimized Methods for the Isolation of Arabidopsis Female Central Cells and Their Nuclei

Yeonhee Choi,Kyunghyuk Park,Jennifer M. Frost,Adam James Adair,Dong Min Kim,Hyein Yun,Janie S. Brooks,Robert L. Fischer 한국분자세포생물학회 2016 Molecules and cells Vol.39 No.10

The Arabidopsis female gametophyte contains seven cells with eight haploid nuclei buried within layers of sporophytic tissue. Following double fertilization, the egg and central cells of the gametophyte develop into the embryo and endosperm of the seed, respectively. The epigenetic status of the central cell has long presented an enigma due both to its inaccessibility, and the fascinating epigenome of the endosperm, thought to have been inherited from the central cell following activity of the DEMETER demethylase enzyme, prior to fertilization. Here, we present for the first time, a method to isolate pure populations of Arabidopsis central cell nuclei. Utilizing a protocol designed to isolate leaf mesophyll protoplasts, we systematically optimized each step in order to efficiently separate central cells from the female gametophyte. We use initial manual pistil dis-section followed by the derivation of central cell proto-plasts, during which process the central cell emerges from the micropylar pole of the embryo sac. Then, we use a modified version of the Isolation of Nuclei TAgged in specific Cell Types (INTACT) protocol to purify central cell nuclei, resulting in a purity of 75-90% and a yield sufficient to undertake downstream molecular analyses. We find that the process is highly dependent on the health of the original plant tissue used, and the efficiency of protoplasting solution infiltration into the gametophyte. By isolating pure central cell populations, we have enabled elucidation of the physiology of this rare cell type, which in the future will provide novel insights into Arabidopsis reproduction.

Possible quantum Hall effect in a magnetic-field-induced phase transition in the quasi-one-dimensional CDW organic conductor, HMTSF–TCNQ

Murata, Keizo,Fukumoto, Yuhei,Yokogawa, Keiichi,Kang, Woun,Takaoka, Ryo,Tada, Ryota,Hirayama, H.,Brooks, James S.,Graf, David,Yoshino, Harukazu,Sasaki, Takahiko,Kato, Reizo Elsevier 2015 PHYSICA B-CONDENSED MATTER - Vol.460 No.-

<P><B>Abstract</B></P> <P>We have studied the angular dependence of magnetoresistance and Hall effect of the CDW organic conductor, HMTSF–TCNQ in order to see whether a magnetic-field-induced phase exists in the charge density wave (CDW) system, similarly to the magnetic-field-induced SDW phases in (TMTSF)<SUB>2</SUB>X. The anomaly in magnetoresistance was observed only around the pressure where the CDW is almost suppressed, i.e. around 0.8–1.1GPa, but neither at low pressures (0 and 0.5GPa) nor at high pressure above 2GPa. This behavior is quite similar to that of (TMTSF)<SUB>2</SUB>X. At 1.1GPa anomalies were found at fields of 0.2T and 10T. We speculate that at 1.1GPa the field-induced phase is located between 0.2T and 10T, where 1D Fermi surface sheet and 2D Fermi-surface pocket are present. The <I>R</I> <SUB> <I>xy</I> </SUB> shows plateau structure and <I>R</I> <SUB> <I>xx</I> </SUB> was very small in the same region, suggestive of quantum Hall effect.</P>