Fine structure of the pterin layer in the dermis of Rana pipiens

Summary The fine structure of the pterin layer was investigated in both wild type Rana pipiens and Rana pipiens homozygous for the speckle mutant gene. No difference in morphology of the layer was noted between the wild type and mutant. The layer lines the outer surface of the stratum compactum of the dermis and separates this stratum from the stratum spongiosum. The pterin layer consists of extra-cellular material and contains membrane-bounded granules filled with fine spicules. Many of the spicules are somewhat similar in appearance to the initial calcification loci present in developing membrane bone. The layer first appears in the tadpole at approximately stage 14 (Taylor and Kollros, 1946); subsequent developmental stages are described.This work was supported by United States Public Health Service Fellowships (to G.E.W.) 1-FO2-CA32869-01 and 5-FO2-CA32869-02; (to L.W.B.) 1-FO2-GM-32, 906-01 and 1-FO2-GM-32-906-02; by funds from an Institutional Grant to the University of Colorado from the American Cancer Society (L.W.B.); by National Research Council (Canada) Grant # A6209 (L.W.B.); by Program Project HD-02282 of the National Institutes of Health; and by Health Sciences Advancement Award FR-02084 from the National Institutes of Health.     

Expression and distribution of cytosolic 6-phosphogluconate dehydrogenase isozymes in maize

Maize (Zea mays L.) cytosolic 6-phosphogluconate dehydrogenase isozymes (EC 1.1.1.44; 6-PGD) are encoded by unlinked lociPgd1 andPgd2. Two families from a Robertson's Mutator line were isolated which have no detectable expression ofPgd2. ThesePgd2-null mutants and aPgd1-null line were used to generate plants homozygous for null alleles at both cytosolic 6-PGD loci. The specific activity of 6-PGD in the double-null mutant was between 20 and 30% of wild-type levels in root extracts. The double-null mutant was reproductively viable in a moderate environment, suggesting that wild-type levels of cytosolic 6-PGD activity are not essential for growth. Isozyme dimer ratios in roots, leaves, and scutellum were binomial and reflected the wild-type gene copy number. 6-PGD isozymes showed tissue- and cell type-specific expression. This research was supported by grants from the United States Department of Agriculture (Individual Postdoctoral Grant 89-37264-4837 to J.B.-S.) and the National Institutes of Health (Postdoctoral Grant 5-F32-GM11112-03 to J.B.-S. and Research Grant 2-R01-GM21734 to M.F.).     

Immunochemical cross-reactivity between intact purified myelin basic protein (MBP) and the synthetic encephalitogenic peptide S49

Three antisera to myelin basic protein—a rabbit antiserum pool against rat myelin, a rabbit antiserum pool against rat myelin basic protein (MBP), and a monkey antiserum against bovine MBP—were found to contain detectable levels of antibodies that would bind radiolabeled S49 (GSLPQKAQRPQDENG). Strongly encephalitogenic in Lewis rat, S49 is a synthetic peptide representing residues 69–84 of bovine MBP with a deletion of glycine-76 and histidine-77 to make it analogous to rat and guinea pig MBPs. The rabbit antimyelin antiserum and the monkey anti-MBP antiserum contained antibodies directed against a non-sequential determinant that required asparagine 84, the glycine-histidine deletion, and residues 69–71 for maximal activity. S49-reactive antibodies from the rabbit anti-MBP antiserum were directed solely against a sequential determinant comprising residues 69–71. S49-reactive antibodies from all three antisera reacted in liquid phase with purified intact rat, guinea pig, and bovine MBP showing that the determinant is exposed for B cell recognition even in bovine MBP and can serve both as immunogen and reactant.This work supported at Duke University Medical Center by Research Grant NS-10237 from the National Institutes of Health of the U.S. Public Health Service and the Medical Scientist Training Program Grant #5-T32-OMO-7171-08; at St. Luke's Hospital Center by NS-15322 from the National Institutes of Health of the U.S. Public Health Service; and at Northwestern University by Research Grant NS-06262 from the National Institutes of Health of the U.S. Public Health Service.     

On the appearance of chaos in a model of the Belousov reaction

Summary A modified version of the Oregonator is analysed as a model of oscillations, bistability and chaos in the bromate-malonic acid-cerium reaction.This study was supported by the National Cancer Institute, USA, Grant No. 5 F32 CAO5152-02.     

Protein-phosphatase inhibitors block root hair growth and alter cortical cell shape ofArabidopsis roots

Emerging evidence suggests that protein phosphatases play an important role in the growth and development of higher plants. We report here on the effects of okadaic acid and calyculin-A, two specific and potent inhibitors of the type-1 and type-2A families of serine/ threonine protein phosphatases, on the growth and development ofArabidopsis thaliana L. roots. Application of these drugs in nanomolar ranges arrested root hair growth, severely affected the shape of cells within the zone of elongation and inhibited root growth rates. Root hair elongation was inhibited by concentrations of okadaic acid and calyculin-A as low as 3 nM. The pleiotropic effects of okadaic acid and calyculin-A point to multiple functions for type-1 and -2A protein phosphatases in controlling root growth and development.We thank Kelly Aldrich for excellent technical assistance. This research was supported by National Science Foundation Grant MCB-9219075 to J.C.W.; University of Missouri Food for the 21st Century Program; National Institute of Health Grant DHHS 5 F32 GM14433-02 to R.D.S.; and this material is partially based upon work supported by the Cooperative State Research Service, U.S. Department of Agriculture, under Agreement No. 92-37304-7868 to T.I.B.     

Murine liver arylsulfatase B processing influenced by region on chromosome 17

SM/J liver arylsulfatase B has a more rapid electrophoretic mobility and occurs as a series of more acidic isozymes following electrofocusing in narrow pH gradients than the liver enzyme from C57BL/6J mice. The SM/J and C57BL/6J electrofocusing patterns were both converted to a single isozyme with similar isoelectric points by pretreatment with neuraminidase, suggesting that the SM/J and C57BL/6J isozymes differed with respect to their sialic acid content. Arylsulfatase B electrofocusing and thermostability phenotypes segregated independently among progeny of SM/J×C57BL/6J crosses, suggesting that the electrofocusing phenotypes were not determined by different alleles at As-1, the putative structural locus for arylsulfatase B. Comparison of the joint segregation of hepatic acid phosphatase electrophoretic patterns and liver arylsulfatase B electrofocusing profiles revealed that the electrofocusing profiles may be determined by a region on chromosome 17 near or identical to Apl. Kidney, brain, and spleen arylsulfatase B electrofocusing patterns did not appear to differ between SM/J and C57BL/6J mice.This research was supported in part by Biomedical Sciences Research Support Grant RR-07030, by NIGMS Grant 1-RO1GM27707-01, and by Grant 1–570 from the National Foundation/March of Dimes.     

Cholera toxin stimulation of human mammary epithelial cells in culture

Summary Addition of cholera toxin to human mammary epithelial cultures derived from reduction mammoplasties and primary carcinomas greatly stimulated cell growth and increased the number of times the cells could be successfully subcultured. Other agents known to increase intracellular cAMP levels were also growth stimulatory. The increased growth potential conferred by cholera toxin enhances the usefulness of this cell culture system. This work was supported by USPHS Grant CA-24844 from the National Cancer Institute and Grant CD-61B from the American Cancer Society.     

A gelatin-specific protease from hamster lung-derived cell cultures

Summary Gelatin-specific protease activity from hamster lung fibroblasts and their culture media is described. The fibroblasts were derived from hamster lung explant cultures. The gelatin-specific protease activity is latent and seen only after dialysis of either cells or media. The enzyme activity shares many properties of previously reported gelatinases. The activity is inhibited by EDTA, cysteine, and dithioerythritol, whereas it is not inhibited byp-chloromecuribenzoate,N-ethyl maleimide, or phenylmethylsulfonyl fluoride. Of all substrates tested, activity was observed only against gelatin and not against other substrates tested. It was inactive toward collagen, elastin, and methemoglobin. This enzyme may have a role in the digestion of collagen that has been previously cleaved by mammalian collagenase. This research was supported by Program Project Grant HL-19717 from the National Heart, Lung, and Blood Institute, Grant AG 000-38-02 from the National Institute of Aging, and National Institute of Health Grant 5T32HL07035.     

Reviews of publications

Evolutionary Dynamics of a Natural Population. The Large Cactus Finch of the Galapagos , by B. Rosemary Grant & Peter R. Grant.
Species Dispersal in Agricultural Habitats , edited by R. G. H. Bunce and D. C. Howard.
The Dictionary of Cell Biology , edited by J. M. Lackie and J. A. T. Dow.
The Mirror of Creation , by E. J. Ambrose.
The Fate of the Forest , by Susanna Hecht and Alexander Cockburn.     

Increased tritiated thymidine-labeling index of bone marrow myeloblasts following BCG administration in man

Summary The in vitro (³H)thymidine-labeling index of bone marrow myeloblasts was determined in eight hematologically normal individuals before and after the administration of Bacillus Calmette-Guérin twice weekly for 2 weeks. The mean labeling indexes of myeloblasts were 30.5 and 45.2% respectively (P<0.004).Further characterization of this stimulation of proliferation of bone marrow myeloblasts could provide some rationale for combining cytotoxic drugs and immunotherapy in cancer patients.The present work was supported by the Fonds Cancérologique de la Caisse Générale d'Epargne et de Retraite de Belgique and by Euratom Grant No. 161-76-1. B 10B and by the NCI Grant No. 2R 10CA 11488-07     

Discharge and restitution of secretory material in the rat parotid gland in response to isoproterenol

Summary The sequence of morphological events occurring during discharge and restitution of secretory material in the rat parotid in response to isoproterenol administration has been studied using the electron microscope. With the dose used, discharge of secretory granules began within 5 min following injection and was complete by 40 mim. Intracellular accumulation of normal-appearing secretory material became evident at 6 hours, and restitution of resting quantities of secretory material was achieved between 12 and 18 hours after injection. Cellular events occurring during secretory discharge and restitution are discussed.This project was supported by Training Grant No. 5-Ti-GH-326 and by Predoctoral Research Grant No. 1-F1-GM-32, 528-01, National Institutes of Health. I wish to express my gratitude to Dr. Henry S. di Stefano under whose directorship this project was carried out.     

Linkage of the locus for conversion of albumin (Acf-1)in the house mouse,Mus musculus

The linkage of the locus for conversion of albumin (Acf-1) has been established on chromosome 1 with the following gene order and recombination percentages: Id-1 19.3±5.2% Acf-1 4.2±1.7% Dip-1 18.4±4.2% Lp.This work was supported by NIH Postdoctoral Fellowship 1F32 GM0527701, Grant BMS75-03397 from the National Science Foundation, Grant ACS VC-17-R from the American Cancer Society, and Contract NO1-ES42159 from the National Institute of Environmental Health Sciences. The Jackson Laboratory is fully accredited by the American Association for the Accreditation of Laboratory Animal Care.     

In vitro translation of maize ADH: Evidence for the anaerobic induction of mRNA

Total cellular RNA from anaerobically stressed maize seedling roots was used to stimulate in vitro translation of authentic maize alcohol dehydrogenase (ADH) in a rabbit reticulocyte lysate system. Total products from such reactions were displayed on NEPHGE-SDS two-dimensional gels and the Adhl-specific translation products were identified by using RNA from sib seedlings segregating for Adhl charge and size variants. The application of a rapid RNA isolation procedure allowed the efficient isolation of biologically active RNAs from small amounts of seedling material. Maize ADHs translated in vitro are identical in size to in vivo ADH. Further, no ADH was detected in the products of an in vitro translation reaction stimulated by total RNA from aerobically grown seedlings. This suggests that induction of ADH protein by anaerobic stress is accomplished by production of Adh mRNA rather than activation of sequestered mRNA. The mRNAs for maize ADH1 and ADH2 are among a small class of mRNAs induced during anaerobiosis.Research was supported by NSF Grant PCM 76-11009. M.D.B. is supported by National Institute of Health Grant PHS 5 T32 GM07227-04. R.J.F. is a Predoctoral Trainee in Genetics supported by National Institute of Health Training Grants 82 and 7757 from the National Institute of General Medical Sciences.     

A Link Between Histone Deacetylase Inhibitors and NF-kappaB Signaling

Commentary to:

An Intact NF-κB Pathway is Required for Histone Deacetylase Inhibitor-Induced G₁ Arrest and Maturation in Human Myeloid Leukemia (U937)

Yun Dai, Mohamed Rahmani, Steven Grant     

Thessaly variant of Glucose-6-phosphate Dehydrogenase

Summary A new variant of the erythrocytic enzyme Glucose-6-phosphate Dehydrogenase was detected in two unrelated Greek individuals. The variant was designated G6PD Thessaly. It is characterized by normal levels of G6PD activity in the red cells and electrophoretic migration slower than G6PD B on phosphate and T.E.B. buffers while faster than G6PD B on Tris-HCl buffer. In addition, the Thessaly variant has distinctly decreased affinity for NADP.This study was supported by National Institutes of Health Grant GM 15253.     

Co-expression with RadA and the characterization of stRad55B, a RadA paralog from the hyperthermophilic crenarchaea Sulfolobus tokodaii

ST0838 (designed stRad55B) is one of the four RadA paralogs (or Rad55 homologues) in the genome of the hyperthermophilic crenarchaeon Sulfolobus tokodaii. The gene is induced by UV irradiation, suggesting that it is involved in DNA recombinational repair in this organism. However, this protein could not be expressed normally in vitro. In this study, thermostable and soluble stRad55B was obtained by co-expression with S. tokodaii RadA (stRadA) in E. coli, and the enzymatic properties were examined. It was found that stRad55B bound ssDNA preferentially and had a very weak ATPase activity that was not stimulated by DNA. The recombinant protein inhibited the strand exchange activity promoted by stRadA, indicating that stRad55B might be an inhibitor to the homologous recombination in this archaeon. The results will be helpful for further functional and interaction analysis of RadA paralogs and for the understanding of the mechanism of recombinational repair in archaea. Supported by the National Basic Research Program of China (Grant No. 2004CB719604) and National Natural Science Foundation of China (Grant Nos. 30470386 and 30700011)     

Determination of the ionization potential and the electron affinity of various biologically active substances by polarography

The electron affinity and ionization potential of various biological substances were measured by polarography and compared with their effect on growth ofE. coli.This research was supported by the National Science Foundation, Grant GM 10383, the Josephine B. Crane Foundation, and the Thayer Lindsley Foundation.