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Biomedical subjects

J F Collins

Publications and source records attributed to J F Collins.

At least 127 records · Page 7Linked to original sources
PubMed1985

Anticonvulsant action of beta-kainic acid in mice. Is beta-kainic acid an N-methyl-D-aspartate antagonist?

An effect of the beta-stereoisomer of kainic acid on seizures produced by intracerebroventricular injections of excitatory amino acids was tested in mice. beta-Kainic acid preferentially antagonizes myoclonic seizures induced by N-methyl-D-aspartate and quinolinate, has less pronounced anticonvulsant action against alpha-kainate, D-homocysteinesulphinate and quisqualate, and no effect on convulsions induced by L-glutamate. The anticonvulsant activity of beta-kainic acid matches that of 2-amino-7-phosphonoheptanoic and kynurenic acids, both preferential N-methyl-D-aspartate receptor antagonists, and differs considerably from the profile of anticonvulsant action of gamma-D-glutamylaminomethylsulphonic acid, a preferential kainate/quisqualate antagonist.

Animals↗
PubMed1985

Muscle relaxant action of excitatory amino acid antagonists.

Antagonists of neuronal excitation induced by dicarboxylic amino acids were tested in genetically spastic rats of the Han-Wistar strain. These animals exhibit an increased muscle tone which can be measured as a spontaneous tonic activity in the electromyogram of the gastrocnemius-soleus muscle. Compounds that block excitation due to N-methyl-D-aspartic acid reduced the spontaneous activity measured in the electromyogram in a dose-related manner. The most potent compounds, 2-amino-7-phosphonoheptanoic and kynurenic acids were effective muscle relaxants when given either intraperitoneally or intracerebroventricularly. 2-Amino-5-phosphonopentanoic acid possessed much weaker muscle relaxant activity, while L-glutamic acid diethylester was inactive by either route. The results suggest that blockade of N-methyl-D-aspartic acid receptors results in a myorelaxant effect. Specific antagonists of excitation at N-methyl-D-aspartic acid receptors may provide a new class of muscle relaxants.

2-Amino-5-phosphonovalerate↗
PubMed1985

Depression Adjective Check Lists: Spanish, Hebrew, Chinese and English versions.

Data are presented on the translation, reliability, concurrent validity, and norms of the Spanish, Hebrew, and Chinese versions of three equivalent forms of the Depression Adjective Check Lists, and comparisons with the English version are made. Reliability estimates (split-half, alternate form, and internal consistency) for the four versions are quite similar in magnitude (.79 to .94). Concurrent validity was determined in each case by means of correlations with translated versions of a self-rating scale of depression, the Bradburn Scale, the Cantril Self-Anchoring Striving Scale, and the Katz Psychophysiologic-psychosomatic Symptom Scale. The English and Hebrew norms are based upon national probability sampling.

Cross-Cultural Comparison↗
PubMed1985

Treatment characteristics of psychiatric programs that correlate with patient community adjustment.

This large Veterans Administration cooperative study sought to identify the ward milieu characteristics of effective psychiatric programs. It was developed as a multivariable, correlational study that involved systematic observations of program characteristics and outcome effectiveness of wards as they operated in their usual manner. Seventy-nine wards in 18 hospitals provided 11,283 patients eligible for follow-up. Eleven treatment characteristics were found to be correlated to patients' community adjustment 3 months after discharge. These characteristics were classified into five general categories: Patient-staff interaction, patient activities, medication practices, ward physical environment, and nursing staff rotation. The major conclusions are: wards do differ in their effectiveness as measured by ratings of patient posthospital adjustment; and treatment characteristics make a difference in program effectiveness as measured by patients' posthospital adjustment.

Aggression↗
PubMed1985

beta-Kainic acid is not an amino acid antagonist.

beta-Kainic acid has been reported to have anticonvulsant properties. In view of its structural relationship to alpha-kainic acid it has therefore been tested for antagonist activity at excitatory receptors for N-methylaspartate, quisqualate and alpha-kainate using anaesthetized rats and brain slice preparations. No antagonism was found against these three agonists though beta-kainate itself caused excitation. If beta-kainate interferes with excitatory amino acid neurotransmission it probably acts presynaptically.

Amino Acids↗
PubMed1985

Isolation and characterization of fibronectin from baboon plasma.

Fibronectin has been purified from baboon plasma by affinity chromatography on immobilized gelatin. Baboon fibronectin has subunit sizes, CNBr and thermolysin peptide patterns and an amino acid composition similar to human fibronectin. In Ouchterlony plates, baboon plasma fibronectin gives an immunological reaction of identity with human fibronectin, and a partial reaction with hamster fibronectin, using a goat antibody to human fibronectin. By radial immunodiffusion and rocket immunoelectrophoresis, using the same antibody, baboon fibronectin gives a dose response pattern similar to human fibronectin. Plasma concentrations of fibronectin in baboons are similar to those in humans. Fibronectin is thus another interesting protein that is closely related to its human counterpart and can be studied in subhuman primates using available antibodies to the human protein.

Amino Acids↗
PubMed1985

Studies on the elastolytic activity of chymotrypsin.

Chymotrypsin can completely solubilize insoluble [3H]-labeled ligamentum nuchae elastin. At similar enzyme levels, trypsin solubilizes only 5% of the elastin substrate whereas pancreatic elastase completely solubilizes the elastin at one-tenth the concentration required for chymotrypsin solubilization. The elastolytic activity of chymotrypsin is dependent on Ca+2, is enhanced by SDS, and is inhibited by NaCl at concentrations above 10 mM. The elastolytic activity of chymotrypsin is also inhibited by TPCK, a chymotrypsin specific inhibitor, but not by TLCK, a trypsin specific inhibitor. Neither TPCK nor TLCK abolish the elastolytic activity of pancreatic elastase. The sizes of [3H]elastin fragments produced by the elastolytic activity of chymotrypsin are similar to those produced by pancreatic elastase, and larger than those produced by trypsin.

Animals↗
PubMed1985

Nitric acid-induced injury in the hamster lung.

Severe airway lesions can result following exposure to various pathogens or toxic gases and can show a variety of pathologic lesions including necrotizing bronchitis, bronchiolitis and bronchiectasis. The purpose of this study was to develop a chronic airway lesion in the hamster, a species recognized for its lack of endogenous pulmonary disease. We have successfully adapted a technique of inducing rabbit airway lesions with nitric acid to the hamster lung and have characterized the morphologic, morphometric and biochemical features of the model. Following a transorotracheal instillation of 0.5% HNO3 in saline, Syrian golden hamsters showed during a 60-day study period a spectrum of airway changes including acute bronchitis, acute bronchiolitis, obliterative bronchiolitis, bronchiolectasia and bronchiectasis. Morphometric changes in the HNO3-treated hamsters included decreased lung volumes and decreased internal surface areas. Biochemical changes showed increases in lung weight and in total collagen and elastin. The model is useful because a prolonged insult to the airways develops rapidly and persists over a long period of time, important features for investigations designed to study the effects of superimposed insults upon pre-existent airway lesions.

Animals↗
PubMed1984

Kainic acid derivatives with anticonvulsant activity.

beta-Kainic acid, and the glycine and amino-methylphosphonate derivatives of alpha- and beta-kainic acid, have been injected intracerebroventricularly in DBA/2 mice, that show sound-induced seizure responses. An anticonvulsant effect is observed with marked protection against the tonic and clonic phases of the seizure response. ED50 values against clonus are (in mumol): beta-kainic acid, 0.09; beta-kainylglycine, 0.11; alpha-kainylglycine, 0.28; alpha-kainylaminomethylphosphonate, 0.31; beta-kainylaminomethylphosphonate, greater than 1.5. In addition a direct convulsant effect occurs after the alpha-kainyl derivatives.

Acoustic Stimulation↗
PubMed1984

Anticonvulsant action of amino acid antagonists against kindled hippocampal seizures.

Electrical stimulation of the ventral hippocampus 5 times daily produced significant seizure activity (stage 4), but further stimulations seldom produced full motor seizures (stage 5). Blockade of these seizures with amino acid antagonists, phosphonocarboxylic acids, was achieved but with a reverse order of potency to that seen with the kindled amygdala. Thus APB was the most potent and APH the least potent analog tested. These results indicate that the kindling of different limbic brain areas may involve different neuronal substrates even if the development of the seizure activities are similar.

2-Amino-5-phosphonovalerate↗
PubMed1984

Applications of parallel processing algorithms for DNA sequence analysis.

Programs have been written to apply parallel processing algorithms to the main methods of DNA sequence analysis. These programs allow the largest of currently interesting problems to be handled on a medium-sized computer system. The abundance of information otherwise not readily available has suggested new methods for the detection of homology and order in sequences.

Animals↗
PubMed1984

The pharmacology of the piperidine dicarboxylates on the crustacean neuromuscular junction.

The effects of the four cis-piperidine dicarboxylate analogues (PDAs) on the neuromuscular junction of the hermit crab (Eupagurus bernhardus) were examined. Intracellular recordings of evoked excitatory junction potentials (EJPs) and the membrane potential were made. All four analogues were active as agonists and depolarized the fibre membrane. The dose-response curves for the 2,3 and 2,6-piperidine dicarboxylates were similar to that for L-glutamate but were one tenth as potent. The dose-response curves for the 2,4 and 2,5-piperidine dicarboxylates had shallower gradients and lower maxima indicating lower potencies. The piperidine dicarboxylates non-competitively antagonized and glutamate-induced potential and reversibly attenuated the amplitude of the junction potential, with no change in membrane input resistance. The decrease in amplitude of the glutamate-induced potentials produced by a train of ionophoretic pulses was reversibly blocked by incubation with any of the dicarboxylates. The results indicate that the piperidine dicarboxylates prevent the development of receptor desensitization. The significance of these findings is discussed.

Animals↗
PubMed1984

Anticonvulsant and proconvulsant properties of a series of structural isomers of piperidine dicarboxylic acid.

Anticonvulsant and convulsant effects of various piperidine dicarboxylic acids have been evaluated following their intracerebroventricular (i.c.v.) or intraperitoneal (i.p.) injection in DBA/2 mice, a strain of mice genetically susceptible to sound-induced seizures. Protection against sound-induced seizures occurred after intraventricular administration of (+/-)cis-2,3-piperidine dicarboxylic acid (0.017-0.045 mumol), (+/-)trans-2,3-piperidine dicarboxylic acid (0.018-0.33 mumol) and (+/-)cis-2,4-piperidine dicarboxylic acid (0.57-1.68 mumol). Protection against sound-induced seizures occurred after intraperitoneal injection of (+/-)cis-2,3-piperidine dicarboxylic acid (0.52-1.8 mmol/kg). Myoclonus or convulsions occurred at various times after the intraventricular injection of cis-2,3-piperidine dicarboxylic acid, trans-2,3-, cis-2,4-, cis-2,5- and cis-2,6-, piperidine dicarboxylic acids, and after the intraperitoneal injection of trans-2,3-piperidine dicarboxylic acid. The latter effect was blocked by pretreatment with 2-amino-7-phosphonoheptanoic acid (0.33 mmol/kg, i.p.) a potent and specific antagonist of excitation induced by N-methyl-D-aspartate. The anticonvulsant action of cis-2,3-piperidine dicarboxylic acid and the convulsant action of trans-2,3-piperidine dicarboxylic acid were associated with predominant antagonist and agonist actions respectively, at receptors preferring N-methyl-D-aspartate.

Acoustic Stimulation↗
PubMed1984

Ionic regulation of the binding of DL-[3H]2-amino-4-phosphonobutyrate to L-glutamate-sensitive sites on rat brain membranes.

The effects of ions on the binding of the excitatory amino acid analogue DL-[3H]2-amino-4-phosphonobutyrate to L-glutamate-sensitive sites on rat brain synaptic membranes was investigated. The divalent cations manganese, magnesium, strontium, and particularly calcium, produced a marked enhancement in specific binding. However, this effect was manifest only in the presence of added chloride, or to a lesser extent, with bromide ions. Application of saturation analysis revealed that both chloride and calcium acted to increase the binding site density in a concentration-dependent manner, without affecting the dissociation constant. The only other ionic species found to have a significant effect on 2-amino-4-phosphonobutyrate binding was sodium, which produced an apparent reduction in site affinity, without modifying the binding site density. Although the significance of these striking ionic effects is as yet unknown, it seems feasible that chloride (and possibly also calcium) ions may serve a role in regulating the interaction of excitatory amino acids with their physiological receptors.

Aminobutyrates↗
PubMed1984

Treatment characteristics of effective psychiatric programs.

As part of a large cooperative study undertaken by the Veterans Administration (VA) to identify the ward characteristics of effective psychiatric programs, 123 treatment characteristics were analyzed using four measures of patient posthospital community adjustment derived from the Veterans Adjustment Scale and the Personal Adjustment and Role Skills Scale. The authors found that wards that performed best on the measures were characterized by staff who perceived less order and organization on the ward, nursing staffs with less shift rotations, a lower percentage of socially passive patients, a higher percentage of patients off the ward, a higher percentage of neurotic patients on no antipsychotic drugs at discharge, and lower dosages of the minor tranquilizers. These six treatment characteristics accounted for 29 percent of the variance in the outcome measures. After discussing the relationship of the findings from this study to the findings from a previous article on the VA study, which analyzed ward setting characteristics and program outcome, the authors conclude that ward programs differ in their effectiveness as measured by ratings of patient post-hospital community adjustment and that both setting and treatment characteristics make a difference in that adjustment.

Hospitals, Veterans↗