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H R Garner

Publications and source records attributed to H R Garner.

33 records · Page 2Linked to original sources
PubMed1997

Rescuing corrupted gel files from Model 377 and 373 DNA Sequencers.

Automated DNA sequencing requires the intensive use of computers to handle the large amount of data taken. When a computer failure occurs and the data are no longer accessible, all the expense and effort that went into the sequencing experiment is lost. By using the data storage architecture of Macintosh computers to our advantage, we may prevent this loss in the case of automatic sequencers from PE Applied Biosystems. The software required to allow the experimenter to do this has been written and is available free of charge.

Automation↗
PubMed1997

Butorphanol-mediated antinociception in mice: partial agonist effects and mu receptor involvement.

In the present experiments, we characterized the agonist and antagonist effects of butorphanol in mice. In the mouse radiant-heat tail-flick test, the mu agonists morphine and fentanyl and the kappa agonist U50,488H were fully effective as analgesics, whereas butorphanol was partially effective (producing 82% of maximal possible analgesic effect). Naltrexone was approximately equipotent in antagonizing the effects of morphine, fentanyl and butorphanol; in vivo apparent pA2 values for these naltrexone/agonist interactions were 7.5 (unconstrained). Naltrexone was approximately 10 times less potent in antagonizing the effect of U50,488H (average apparent pK(B) = 6.7). The selective mu antagonist beta-funaltrexamine (0.1-1.0 mg/kg) antagonized the effects of butorphanol in a dose-dependent insurmountable manner. Pretreatment with nor-binaltorphimine (32 mg/kg), a kappa-selective antagonist, did not reliably antagonize butorphanol, and naltrindole (20 and 32 mg/kg), a delta-selective antagonist, failed to antagonize the effects of butorphanol. Low doses of butorphanol (1.0, 1.8 or 3.2 mg/kg) caused parallel, rightward shifts in the dose-effect curve for morphine and parallel leftward shifts in the dose-effect curve for U50,488H. Taken together, the results of the present study suggest that butorphanol is a partial agonist in the mouse radiant-heat tail-flick test and that activity at mu receptors accounts for the majority of its antinociceptive effects.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗
PubMed1995

Effect of lipopolysaccharide on nitric oxide synthase activity in rat proximal tubules.

Renal proximal tubules isolated from the rat possess nitric oxide synthase (NOS) activity that is calcium/calmodulin dependent and stereoselectively inhibited by NG-monomethyl-arginine (NMMA). In the absence of added Ca2+ and calmodulin, activity was reduced 84 +/- 13% compared with the activity in the presence of 2 mM Ca2+ and 25 micrograms/mL calmodulin. Inhibition by EGTA (10 mM) was 95 +/- 5% and by calmidazolium (R24571, 250 microM) was 99 +/- 1%. Inhibition by L-NMMA (100 microM) was 78 +/- 13% and by D-NMMA (100 microM) was 7 +/- 7%. The majority of NOS activity was found in the soluble fraction. NOS activity in isolated proximal tubules was also examined 6 hr after a single i.v. injection of lipopolysaccharide. Activity was increased significantly (P < 0.05) in the soluble fraction by 2-fold [from 0.320 +/- 0.052 to 0.648 +/- 0.046 (nmol/mg protein/30 min)] and in the particulate fraction by 3-fold [from 0.081 +/- 0.030 to 0.256 +/- 0.034 (nmol/mg protein/30 min)]. All activities were inhibited by EGTA. These data demonstrate that proximal tubules express a calcium/calmodulin-dependent NOS activity that is increased in vivo by lipopolysaccharide.

Amino Acid Oxidoreductases↗
PubMed1993

High-throughput PCR.

The number of PCR samples that can be simultaneously processed has been dramatically increased over existing practices by using a new polycarbonate 864-well microwell plate and a modified air cycling oven. In thirty 9-min cycles, four plates containing 3455 samples can be amplified in 4.5 h. Amplification is rapid, uniform and reliable from sample to sample and run to run. This PCR method can satisfy the Human Genome Project's need for high-throughput sample analysis using PCR.

Biotechnology↗
PubMed1967

Effects of pH and temperature on the wild-type and a mutant form of Neurospora glutamate dehydrogenase.

1. We confirm the observation of Bürk (1965) that Neurospora crassa NADP-linked glutamate dehydrogenase normally exists in an inactive form below pH7.0 and in a fully active form above pH8.0 in either tris or orthophosphate buffer. At pH7.4 the enzyme is about half activated at 25 degrees . 2. The variety of the enzyme produced by the mutant am(2l) shows a similar behaviour except that the transition is shifted about one pH unit in the alkaline direction. 3. The am(2l) enzyme has previously been reported to be activated by brief warming to 30 degrees in phosphate buffer at pH8.0. The wild-type enzyme shows a similar effect at pH7.0. In tris buffer this effect is much less pronounced. 4. The am(2l) enzyme is extremely unstable at 47 degrees at pH7.0; its stability is somewhat greater at lower pH, and is markedly increased by increasing the pH in the range 7.0-8.7. The wild-type enzyme also shows an indication of a stability minimum at pH7.0, but a temperature of 60 degrees is needed for a measurable rate of inactivation. 5. The inactive form of the enzyme is much more subject to thermal irreversible denaturation than is the active form.

Glutamate Dehydrogenase↗
PubMed1966

Detection and isolation of new glycosides in culture broths of Streptomyces hygroscopicus.

Elbein, A. D. (Purdue University, Lafayette, Ind.) J. A. Holowczak, Henry Koffler, and H. R. Garner. Detection and ìsolation of new glycosides in culture broths of Streptomyces hygroscopicus. J. Bacteriol. 91:604-608. 1966.-Four new compounds not previously reported have been isolated and purified from the culture broths of Streptomyces hygroscopicus. The data presented suggest that these compounds may be structurally related to hygromycin A, having similar aglycons but differing in their sugar moieties. Two of the compounds apparently contain d-glucose or l-fucose as their sugar components. The others, like hygromycin A, form crystalline 2,4-dinitrophenylhydrazones, and may contain unusual keto sugars.

Chromatography, Paper↗
PubMedDate not supplied

Analysis of protocol variations on DNA yield.

A modified alkaline lysis method for preparing plasmid DNA from bacterial cells has been developed for automation implementation. The objective of this study was to develop a simplified centrifuge-based protocol that can process samples in a microwell plate. These manual experiments and parametric studies show that the alkaline lysis method can be modified significantly to enable DNA preparations to be done rapidly and reliably by an automated system. The conclusions of this study were (a) centrifugation at < 1500 g is sufficient, (b) centrifugation times need not be extended to compensate for the reduced force, (c) reactions can be done at room temperature, (d) reagent volumes can be reduced over those typically used, and (e) certain reagents can be combined to simplify the handling of fluids.

Automation↗
PubMedDate not supplied

High-throughput DNA preparation system.

A system demonstrating the feasibility of high-throughput, centrifugation-based DNA separations and purifications has been constructed and tested. Samples are currently processed at a rate of 96 in approximately 2-3 h. The device implements an automation-optimized alkaline lysis protocol for the rapid extraction of plasmid or cosmid DNA from 1-ml bacteria cultures. The conditions for optimal culturing in deep-well (96 x 1 ml) microwell plates have been developed, and all sample manipulations are done within these plates. The use of microwell plates was essential to obtain high throughput and make manipulations following the DNA preparation (prep) easier because they can then be manipulated using a variety of commercially available robots. The entire prep system is constructed above a Beckman GPR centrifuge and operated under Macintosh IIcx control. This device has systems for fluid handling, microwell-plate manipulations, and centrifuge rotor alignment.

Automation↗