bluuebunny/crossref_metadata_2025_split huggingface dataset:
Partial Purification and Characterization of Detergent‐Solubilized N‐Sulfotransferase Activity Associated with Calf Brain Microsomes
Authors: Miller R. Robert , Waechter Charles J. 
Published: October 2006

AbstractCalf brain 3′‐phosphoadenosine 5′‐phosphosul‐fate (PAPS):proteoheparan sulfate (PHS) N‐sulfotransfer‐ase activity is solubilized by extracting salt‐washed microsomes with 1% Cutscum. A protocol is described for the partial purification of the sulfotransferase activity utilizing: (1) diethylaminoethyl (DEAE)‐Sephacel, (2) heparin‐Sepharose CL‐6B, and (3) 3′,5′‐ADP‐agarose as chromato‐graphic supports. Sulfotransferase activity was followed by using 3′‐phosphoadenosine 5′‐phospho[35S]sulfate and endogenous acceptors in heat‐inactivated microsomes as exogenous substrates. Two chromatographically distinct fractions (ST1 and ST2) of sulfotransferase activity are resolved on DEAE‐Sephacel. Both sulfotransferase activities have been partially purified and characterized. An apparent purification of the two N‐sulfotransferase fractions of 22– to 29‐fold, relative to the microsomal activity, is achieved by this procedure. Since ST1 appears to represent approximately 24% of the total microsomal activity, a purification of 89‐fold has been estimated for this fraction. Neither sulfotransferase activity was stimulated by MnCl2, MgCl2, or CaCl2 added at 10 mM, nor inhibited by the presence of 10 mM EDTA. ST1 and ST2 are optimally active at pH 7.5–8. Apparent Km values for PAPS of 2.3 μM and 0.9 μM have been determined for ST1 and ST2, respectively. ST1 exhibits N‐sulfotransferase activity primarily and is inhibited by phosphatidylserine whereas the ST2 fraction contains a mixture of N‐ and O‐sulfotransferase activity and is stimulated by phosphatidylserine, phosphatidylcholine, and ly‐sophosphatidylcholine. The detection of two chromatographically distinct sulfotransferase activities raises the possibility that N‐sulfation of proteoheparan sulfates could be catalyzed by more than one enzyme, and that N‐sulfation and O‐sulfation of proteoglycans are catalyzed by separate enzymes in nervous tissue.
Monoclonal Antibodies Specific for the Different Subunits of Asymmetric Acetylcholinesterase from Chick Muscle
Authors: Tsim Karl W. K. , Randall William R. , Barnard Eric A. 
Published: October 2006

AbstractThe asymmetric (20S) acetylcholinesterase (AChE, EC 3.1.1.7) from 1‐day‐old chick muscle, purified on a column on which was immobilised a monoclonal antibody (mAb) to chick brain AChE, was used to immunise mice. Eight mAbs against the muscle enzyme were hence isolated and characterised. Five antibodies (4A8, 1C1, 10B7, 7G8, and 8H11) recognise a 110‐kilodalton (kDa) subunit with AChE catalytic activity, one antibody (7D11) recognises a 72‐kDa subunit with pseudocholinesterase or butyrylcholinesterase (BuChE, EC 3.1.1.8) catalytic activity, and two antibodies (6B6 and 7D7) react with the 58‐kDa collagenous tail unit. Those three polypeptides can be recognised together in the 20S enzyme used, which is a hybrid AChE/BuChE oligomer. Antibodies 6B6 and 7D7 are specific for asymmetric AChE. Four of the mAbs recognising the 110‐kDa subunit were reactive with it in im‐munoblots. Sucrose density gradient analysis of the antibody‐enzyme complexes showed that the anti‐110‐kDa subunit mAbs cross‐link multiple 20S AChE molecules to form large aggregates. In contrast, there is only a 2–3S increase in the sedimentation constant with the mAbs specific for the 72‐kDa or for the 58‐kDa subunit, suggesting that those subunits are more inaccessible in the structure to intermolecular cross‐linking. The 4A8, 10B7, 7D11, and 7D7 mAbs showed cross‐reactivity to the corresponding enzyme from quail muscle; however, none of the eight mAbs reacted with either enzyme type from mammalian muscle or from Torpedo electric organ. All eight antibodies showed immunocytochemical localisation of the AChE form at the neuromuscular junctions of chicken twitch muscles.
Identification of Adenosine Receptor in Rat Pineal Gland: Evidence for A‐2 Selectivity
Authors: Sarda Nicole , Gharib Abdallah , Reynaud Denis , Pacheco Ling Ou Henri 
Published: October 2006

AbstractWe have examined the binding of the adenosine agonist radioligands [3H]cyclohexyIadenosine (3H]CHA), R‐N6‐[3H]phenylisopropyladenosine ([3H]R‐PIA), and 5′‐N‐ethylcarboxamido[3H]adenosine ([3H]NECA) to membranes prepared from rat pineal gland. The results showed that the A‐1‐selective ligands (CHA and R‐PIA) had ±10% specific binding. By contrast, [3H]NECA, a nonselective A‐l/A‐2 li‐gand, gave 72% specific binding of the total binding. This specific binding was insensitive to cyclopentyladenosine (50 M) or R‐PIA (50 μM). To characterize this binding, we sed the N‐ethylmaleimide pretreatment method. Under these conditions, this binding was of high affinity with a KD of 51 ± 10 nM and an apparent Bmax of 1,060 ± 239 fmol/ mg of protein. Specific binding was unaffected by the presence of MgCl2 (10 mM) but was sensitive to guanylyliinidodi‐ phosphate (100 μM) (‐25%), a result suggesting the involvement of an N‐protein mechanism in the coupling of the adenosine receptor labeled by [3H]NECA to other components of the receptor complex. The rank of activity of adenosine analogues in displacing specific [3H]NECA binding was NECA ± 2‐chloroadenosine ±S‐adenosyl‐L‐homocysteine ± CHA. Binding was also displaced by 3‐isobutyl‐l‐meth‐ylxanthine (IC50= 23.6 μM). These findings are consistent with the selective labeling by [3H]NECA of an A‐2‐type adenosine receptor in rat pineal membranes.
Decreased Cyclic AMP Degradation in NG 108‐15 Neuroblastoma × Glioma Hybrid Cells and S49 Lymphoma Cells Chronically Treated with Drugs that Inhibit Adenylate Cyclase
Authors: Thomas John M. , Vagelos Randall , Hoffman Brian B. 
Published: October 2006

Abstract:The increase in hormone‐stimulated cyclic AMP accumulation observed in a variety of intact cells after chronic pretreatment with drugs that inhibit adenylate cyclase activity has been attributed to an increase in adenylate cyclase activity following withdrawal of the inhibitory drug. In NG 108–15 mouse neuroblastoma X rat glioma hybrid cells (NG cells) chronically treated with the muscarinic cholinergic agonist carbachol, we have found a significant decrease in the apparent degradation rate constant for cyclic AMP, in addition to an increase in the prostaglandin E1 (PGE1)‐stimulated cyclic AMP synthesis rate in intact cells. In carbachol‐pretreated NG cells that were stimulated with a maximally effective dose of PGE1, and that accumulated steady‐state cyclic AMP concentrations fourfold or more higher than in control cells, the apparent rate constant for degradation was about 53% lower than the value for control cells. In carbachol‐pretreated cells stimulated with a submaximal dose of PGE1 to yield a steady‐state cyclic AMP concentration comparable to control cells, the apparent rate constant was 31% lower than the value for control cells. In S49 mouse lymphoma cells (S49 cells) chronically treated with an analog of the inhibitory agonist somatostatin, the first‐order rate constant for cyclic AMP degradation in intact cells following isoproterenol stimulation was 29% lower than the value for control cells. Despite these changes in the kinetics of cyclic AMP degradation in intact NG cells and S49 cells, there was either no change or a minimal change (less than 10%) in phosphodiesterase activities assayed in extracts of cells chronically exposed to inhibitory drugs. These data suggest that an alteration in cyclic AMP degradation as well as in cyclic AMP synthesis is an important factor in the withdrawal response following chronic treatment of cells with drugs that inhibit adenylate cyclase.
Retinoic Acid Rapidly Decreases Phosphatidylinositol Turnover During Neuroblastoma Cell Differentiation
Authors: Ponzoni M. , Lanciotti M. 
Published: October 2006

Abstract:Phosphatidylinositol (PI) turnover has recently been implicated in the regulation of cell proliferation and transformation. We have investigated its role in differentiation using LAN‐1 cells, a human neuroblastoma cell line that can be induced to differentiate along the neuronal pathway by retinoic acid (RA). We have found that treatment of LAN‐1 cells with RA is followed by a rapid decrease of inositol phospholipid metabolism, using myo‐[1,2‐3H]inositol or [1(3)‐3H]glycerol. No changes were observed in both [3H]inositol and [3H]glycerol uptake within 24 h of RA treatment. Decreased incorporation of the metabolic precursor into PI 4‐monophosphate and PI 4,5‐bisphosphate occurred within 1 h of RA treatment. No changes were seen in the specific radioactivity of the precursor pools up to 1 h of treatment with RA. Analysis of labeled PI metabolites from prelabeled cells indicated a rapid decrease of inositol 1,4,5‐trisphosphate and 1,2‐diacylglycerol content within 1 min of induction of LAN‐1 cell differentiation. These findings constitute the earliest reported events in neuroblastoma cell differentiation.
Biosynthesis of the Myelin 2′,3′‐Cyclic Nucleotide 3′‐Phosphodiesterases
Authors: Gillespie C. Stewart , Bernier Lise , Brophy Peter J. , Colman David R. 
Published: October 2006

Abstract:We have investigated the site of synthesis of the 2′,3′‐cyclic nucleotide 3′‐phosphodiesterases (CNPs I and II) in rat brain. Rapid kinetics of incorporation of CNPs into oligodendrocyte plasma membrane in the intact brain are consistent with their synthesis on free polysomes. This hypothesis was confirmed by the translation in vitro of RNA isolated from free and bound polysomes, respectively. Unlike myelin basic protein (MBP) mRNAs, CNP mRNAs are not enriched in a myelin‐associated pool of RNA. MBPs, but not CNPs, were found to readily associate in vitro with membrane vesicles derived from rough endoplasmic reticulum. The avidity of MBPs in binding to membranes is probably related to the previously observed spatial segregation of MBP mRNAs into actively myelinating cellular processes of the oligodendrocyte. Such a segregation would ensure that newly synthesized MBPs are immediately incorporated into myelin. In contrast, the CNPs probably associate with the cytoplasmic surface of the oligodendrocyte plasma membrane through interaction with a membrane‐bound receptor.
Glycyl‐l‐Glutamine Stimulates the Accumulation of A12 Acetylcholinesterase but Not of Nicotinic Acetylcholine Receptors in Quail Embryonic Myotubes by a Cyclic AMP‐Independent Mechanism
Authors: Lotwick Helen S. , Haynes L. W. , Ham J. 
Published: October 2006

Abstract:Myotubes prepared from the Japanese quail embryo at 9 days gestation were cultivated in the presence of glycyl‐L‐glutamine (Gly‐Gln, β‐endorphin C‐terminal dipeptide) or glycyl‐glutamic acid (Gly‐Glu), and changes in the activity of acetylcholinesterase (AChE) molecular forms and binding of 125I‐α‐bungarotoxin (αBGT) to cell surface nicotinic acetylcholine receptors were measured. The A12 oligomer was the major form of AChE in the cultures. The activity of all molecular forms of the enzyme was increased in the presence of Gly‐Gln, but Gly‐Glu did not alter AChE activity. In cells infected with the temperature‐sensitive mutant, La31C, of Rous sarcoma virus (ts‐RSV) and transferred to the nonpermissive temperature, the A12 form of AChE was absent, but its activity could be induced following exposure of the cells to Gly‐Gln. When cells treated in this way were incubated in the presence of collagenase, there was a small but significant loss of A12 AChE activity, indicating that Gly‐Gln stimulated the activity of a pool of this oligomer which was mainly but not entirely intracellular. Neither Gly‐Gln nor Gly‐Glu influenced 125I‐αBGT binding after exposure of the cells to the peptides for any duration. Neither Gly‐Gln nor Gly‐Glu influenced the accumulation of cyclic AMP in the cultures. β‐Endorphin is one of a family of peptides that coexist transiently with acetylcholine in lower motoneurones of vertebrates in the perinatal period. This report provides evidence for the selective trophic activity of one of its derivatives toward the postsynaptic cholinergic system in avian muscle cells.
Creatinuria in Diabetics and an Evaluation of Methods for Determining Total Creatinine
Authors: Caspe Saul , Davidson Benjamin , Truhlar Joseph 
Published: October 2006

Creatinuria was found in all 42 diabetic clinic subjects of both sexes taken at random.
Total creatinine determined in the urines of diabetics by the Albanese modification showed a variable deviation (in magnitude and direction) when compared with total creatinine obtained by the Folin method.
Zonal Centrifuges and Other Separation Systems
Authors: Anderson Norman G. 
Published: October 2006

This discussion has included only a partial list of the systems now under development at Oak Ridge as part of the feasibility studies for the Molecular Anatomy Program. It is evident that we are still in the "Robert Goddard" phase of this work. It may not be premature, however, to suggest several conclusions.
Biomedical scientists are discouraged on discovering that developmental efforts cost more, by one or two orders of magnitude, than pure research. In part this is because the full cost of development is generally shown, while in pure research some of the costs may be hidden, or the funds supplied by several sources. Regardless of the reason, the fact remains that development is expensive, as is well understood in nuclear physics and space science.
The role and mission of the large national laboratories, and the kinds of research that should be done in them, have been discussed by Weinberg. The studies described here were in part stimulated by his ideas. We have been unable to find an environment outside a large national laboratory where a program like the Molecular Anatomy Program could be undertaken at the present rate. It appears that programs which attempt to make use of the multidisciplinary approach characteristic of national laboratories should be carefully designed and should evolve experimentally. There is less chance of success when a program is an administrative invention than when it evolves from scientific invention and discovery.
It has been pointed out that most program decisions in science are secret decisions in the sense that the scientific community as a whole does not participate in them. If a choice is to be made at some future time between large-scale expenditures for exploring space, for developing new weapons systems, for constructing new accelerators, for designing large reactors, or for systematically developing methods to explore the molecular basis of human disease, then we will need sufficient information to evaluate each alternative fully, and the information should be generally available. It appears desirable, therefore, to allow the Molecular Anatomy Program to proceed to a point where the full range of its contributions and its inherent limitations may be seen. A rational choice may then be made.
Hydrogeologic Constraints on Yucatn's Development
Authors: Doehring Donald O. , Butler Joseph H. 
Published: October 2006

The Republic of Mexico has an ambitious and effective national water program. The Secretaria de Recursos Hidraulicos (SRH), whose director has cabinet rank in the federal government, is one of the most professionally distinguished government agencies of its kind in the Americas. Resources for the Future, Inc., has been assisting the World Bank with a water planning study which the Bank is undertaking jointly with the Mexican government. The study is intended to provide guidelines for the development of government policies and projects designed to bring about the most efficient use of Mexico's water resources. However, to date, their study has not been directed toward the growing problems of the northern Yucatn Peninsula which are discussed here.
LeGrand suggested that man has inherited a harsh environment in carbonate terranes. In the case of the northern Yucatn Peninsula, the physical environment creates a set of hydrogeologic constraints to future economic and social development. Planning for intermediate and long-range land use on the peninsula must be related directly to the limited and fragile groundwater source. Continued contamination will make future aquifer management a difficult challenge for federal, state, and territorial agencies. We conclude that any strategy for long-range land use in the study area should include establishment of a regional aquifer-monitoring network for long-term measurements of key hydrogeologic parameters, including precipitation, evapotranspiration, water table elevations, and water quality. Information from this network would flow into a central facility for storage, interpretation, and analysis. At present the SRH is collecting some of these data. Expansion of the existing program to provide sound information for regional planning will greatly benefit present as well as future generations. If such a program is implemented, it will represent a model for regional planning in other tropical and subtropical karstic terrains.
Limited proteolysis of human histone deacetylase 1
Authors: Kamath Nayana , Karwowska-Desaulniers Paulina , Pflum Mary Kay H 
Published: October 2006

Abstract

Background
Histone deacetylase (HDAC) proteins are associated with cell proliferation, differentiation, apoptosis, and cancer. Specifically, HDAC1 is linked with cell growth, a hallmark of cancer formation. HDAC1 is a phosphoprotein and phosphorylation at S421 and S423 promotes HDAC1 enzymatic activity and protein association. While single and double point mutants of HDAC1 at S421 and S423 appear functionally similar, the evidence suggests that HDAC1 is phosphorylated simultaneously at both S421 and S423 in vivo. Additional experiments are necessary to probe the role of double phosphorylation of HDAC1 at S421 and S423.

Results
To characterize HDAC1 phosphorylation at S421 and S423, limited proteolysis of HDAC1 was performed for the first time. HDAC1 degraded without production of discrete fragments. By performing concentration-dependent proteolysis, HDAC1 double point mutants with disrupted phosphorylation at S421 and S423 displayed different trypsin sensitivities compared to wild type HDAC1. Unexpectedly, HDAC1 single point mutants with disrupted phosphorylation at either S421 or S423 demonstrated protease sensitivity similar to the wild type HDAC1.

Conclusion
Concentration-dependent proteolysis experiments provide evidence that phosphorylation of S421 and S423 individually contribute to HDAC1 function. In addition, the limited proteolysis experiments support a model where associated proteins promote HDAC1 enzymatic activity, reinforcing the importance of protein interactions in HDAC1 structure and function. Finally, because HDAC1 does not display distinct regions of protease sensitivity, the proteolysis studies suggest that HDAC1 comprises inter-related structural regions.
The acoustic reflex latency test: Clinical application
Authors: Clemis Jack D. , Sarno Cynthia N. 
Published: October 2006

AbstractAcoustic reflex latency is the time interval between onset of an intense auditory stimulus and onset of middle‐ear muscle contraction. The hypothesis was proposed that a retrocochlear lesion involving the afferent (VIIIth nerve) portion of the reflex are should result in a prolongation of the reflex latency. A clinical procedure, the Acoustic Reflex Latency Test (ARLT), its protocol, methods and equipment were developed in order to test this hypothesis clinically. Absolute latency values and interaural latency differences (ILD) were established on 4 populations which included normals, cochlear lesions due to Ménière's disease, cochlear lesions of variable etiology, and 11 cases of surgically confirmed acoustic tumor.Results reveal a dramatic prolongation of latency in the presence of retrocochlear lesions (all tumors). The test was found to be most effective when 1. both ipsilateral and contralateral measurements were made, 2. stimulus frequencies of 1000 Hz and 2000 Hz were employed and 3. both Absolute Latency and ILD were considered.The ARLT, while utilizing an indirect method of measurement, is a valid, cost‐effective, and simple clinical procedure, yielding relative latency values and requiring only minor modifications of standard impedance equipment. The ARLT appears to have a higher efficiency rate than BERA, while providing comparable diagnostic information at a considerable saving of time, cost and personnel.
Vertigo and dizziness of functional origin
Authors: Afzelius Lars‐Erik , Henriksson Nils G. , Wahlgren Louise 
Published: October 2006

AbstractIn patients consulting otologists for vertigo a functional source can be expected in 50% of the patients and more frequently among young females than among older male subjects. Functional vertigo is frequently perceived as a turning sensation inside the head, functional dizziness frequently as a rocking sensation of the whole body, while patients with vertigo of somatic origin frequently seem to complain of a spinning sensation outside the head.The duration pattern of functional vertigo is frequently of a fluctuating or continuous type, while in the nonfunctional subjects it is of 2‐5 hr. duration. In patients with vertigo of functional origin eye‐closure tends to release rather than inhibit nystagmus.
Book Review
Authors: Last John , Leyland Elizabeth , Watanabe Toshio 
Published: October 2006

A Handbook for Teaching and Learning in Higher Education: Enhancing Academic Practice Edited by Heather Fry, Steve Ketteridge and Stephanie Marshall
Improving the Quality of Argument in Higher Education; Final Report (A project funded by the Leverhulme Trust) by Sally Mitchell and
Mike Riddle
Conference Report The Integration of Practice, Theory and Education in Art: The 9th Symposium of the Tohoku Art and Culture Society 8 September 2001 Hotel Metropolitan, Sendai, Japan
Designing Digital Tools in Fisheries: What Fisherfolks Want in Malawi
Authors: Chimseu Patrick Kawaye , Katengeza Samson Pilanazo , Kaunda Emmanuel , Dzanja Joseph , Bennett Abigail 
Published: February 2025

ABSTRACTUse of digital tools is rapidly transforming the world, and Information and Communications Technology (ICT) integration in fisheries presents great opportunities for enhancing fishing‐dependent livelihoods. This article employed latent class analysis and a multinomial logistic regression to explore preferred digital tools for fish traders to address the problem of lack of access to market information. Results from a sample of 548 participants show heterogeneous preferences among fish traders who can be classified into three subgroups: digital‐wise (70%), phone‐wise (24%) and digital‐local (6%) across different platforms and prefer the use of all platforms (USSD, calls, apps, radio and television [TV] programmes). On the basis of platform ranking, traders prefer calls more, followed by app, USSD, radio and TV, respectively. Results further show that social demographic characteristics, including marital status, gender, age and trust among players, influence class membership in different subgroups. To address the diverse needs of traders, there is a need for a free, cross‐platform digital system, call centre/USSD service for convenience, data quality checks, endorsements, the provision of digital credit and stakeholder collaboration to exploit digital fish trade opportunities for Malawi to benefit from the African Continental Free Trade Agreement and not to be left behind in the fourth industrial revolution.