Age-related disappearance of Mayer-like heart rate waves

Healthy elderly subjects (greater than or equal to 65 years) did not show the prominent low frequency (0.07-0.09 Hz) heart rate oscillations (Mayer waves) recorded in young adults immediately following passive upright tilt. This difference may be related to altered autonomic function with physiologic aging.     

9-Methyl-7-bromoeudistomin D,a potent inducer of calcium release from sarcoplasmic reticulum of skeletal muscle

Summary The Ca²⁺-releasing action of several derivatives of eudistomin D isolated from a marine tunicate was compared with that of caffeine. It was found that 9-methyl-7-bromoeudistomin D was approximately 1000 times more potent than caffeine in causing Ca²⁺ release from the sarcoplasmic reticulum.The authors thank Ms A. Muroyama of this institute for her technical assistance and Prof. K. L. Rinehart of University of Illinois for his encouragement.     

A new cell line (XTY) from a tumor of Xenopus laevis.

A new cell line (XTY) was derived from a tumor of a female Xenopus laevis. This cell line has been proliferating in standard amphibian culture medium for more than 4 years (470 generations) and has a doubling time of 75.5 h at 25 degrees C. The cells aggregate into large groups, and their stellate morphology and the expression of desmin demonstrated by immunocytochemistry suggest that their origin is not epithelial.     

Inhibition of rat hepatic dimethylnitrosamine demethylase by cyclic and acyclic nitrosamines and secondary amines

Summary Inhibition of hepatic dimethylnitrosamine (DMN) metabolism by a variety of cyclic and acyclic nitrosamines was demonstrated. Nitrosoproline, a noncarcinogenic nitrosamine, behaved differently from the carcinogenic nitrosamines as an inhibitor for DMN-demethylase. Secondary amines corresponding to the nitrosamines inhibited DMN-demethylase in a manner similar to the nitrosamines.Acknowledgments. This work was supported by Public Health Service Grant 5-PO1-ES00597, Training Grant 1-732-ES07020, and Research Career Development Award 1-KO4-ES00033 (to M.C.A.) from the National Institute of Environmental Health Sciences. We are also grateful for support from Hoffmann-LaRoche Inc., Nutley, NJ.     

A lysosomal enigma CLN5 and its significance in understanding neuronal ceroid lipofuscinosis

Cellular and Molecular Life Sciences - Neuronal Ceroid Lipofuscinosis (NCL), also known as Batten disease, is an incurable childhood brain disease. The thirteen forms of NCL are caused by mutations...     

In vitro dopaminergic neuroprotective and in vivo antiparkinsonian-like effects of Δ3,2-hydroxybakuchiol isolated from Psoralea corylifolia (L.)

Cocktail recipes containing Psoralea corylifolia seeds (PCS) are used to empirically treat Parkinson disease. A PCS isolate Δ³,2-hydroxybakuchiol (BU) can inhibit dopamine uptake in dopamine transporter (DAT) transfected Chinese hamster ovary (CHO) cells, and dopamine reuptake blockade may provide an alternative approach for ameliorating parkinsonism. Here, we assessed the potential dopaminergic neuroprotective, and antiparkinsonian-like activity of BU. BU sample size was increased by using a scale-up extraction paradigm. Pharmacologically, BU significantly protected SK-N-SH cells from 1-methyl-4-phenylpyridinium (MPP⁺) insult, produced striking inhibitory actions on dopamine/norepinephrine uptake and WIN35,428 binding in synaptosomes on in vivo administration, and significantly preventing poor performance on rotarod and dopaminergic loss in substantia nigra in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mice. BU acts by protecting dopaminergic neurons from MPP⁺ injury and preventing against MPTP-induced behavioral and histological lesions in the Parkinson’s disease (PD) model, possibly by inhibiting monoamine transporters. These findings suggest that BU could be meaningful in PD treatment. Received 14 January 2009; received after revision 22 February 2009; accepted 10 March 2009     

DyP-type peroxidases comprise a novel heme peroxidase family

Dye-decolorizing peroxidase (DyP) is produced by a basidiomycete (Thanatephorus cucumeris Dec 1) and is a member of a novel heme peroxidase family (DyP-type peroxidase family) that appears to be distinct from general peroxidases. Thus far, 80 putative members of this family have been registered in the PeroxiBase database (http://peroxibase.isbsib.ch/) and more than 400 homologous proteins have been detected via PSI-BLAST search. Although few studies have characterized the function and structure of these proteins, they appear to be bifunctional enzymes with hydrolase or oxygenase, as well as typical peroxidase activities. DyP-type peroxidase family suggests an ancient root compared with other general peroxidases because of their widespread distribution in the living world. In this review, firstly, an outline of the characteristics of DyP from T. cucumeris is presented and then interesting characteristics of the DyP-type peroxidase family are discussed. Received 14 October 2008; received after revision 12 November 2008; accepted 17 November 2008     

Acute toxicity of folic acid in mice

The toxicity of folic acid (PGA) was studied in different inbred strains of mice. LD50 values of PGA by the i.p. route showed a unique toxicity pattern. In some strains, convulsions, ataxia and weakness were observed. Histopathological study in strains S/RVCri, BDF1, DBA/2 and DBA/2fNCri showed acute renal tubular necrosis.