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Biomedical subjects

T Adams

Publications and source records attributed to T Adams.

At least 19 recordsLinked to original sources
PubMed1992

Human HPRT mutant database: software for data entry and retrieval.

We have developed a computer database containing information on over 1,000 human hypoxanthine guanine phosphoribosyl transferase (HPRT) mutants. Both published and unpublished data are present. The database itself is maintained in a dBASE format (.DBF) and we provide a set of programs to examine and extract information from the database. A program to input information into the database is also supplied. The database and programs are available directly from us or via remote FTP (file transfer protocol) using BITNET/INTERNET. All programs require an IBM-compatible computer, the MS-DOS operating system (version 3.3 or greater), and a hard disk with about 5 megabytes of free disk space. The purpose of the database is 1) to allow investigators to contribute their HPRT mutants directly to the database in a standardized fashion, and 2) to allow access to the entire database with a set of programs that allows manipulation and extraction of data. For example, using our programs it is possible to i) order the database by base pair position, ii) examine only information regarding mutagenesis by a particular agent, iii) search for a particular author, iv) create a report which contains selected portions of the database, the report can be printed or saved as a file. The database will be updated every several months and distributed.

Databases, Bibliographic↗
PubMed1992

Analgesia and behavioral responses of dogs given oxymorphone-acepromazine and meperidine-acepromazine after methoxyflurane and halothane anesthesia.

This study was designed to test analgesia, duration, and cardiovascular changes induced by meperidine (MEP) and oxymorphone (OXY) following methoxyflurane (MOF) and halothane (HAL) anesthesia. Eight healthy dogs were given atropine and acepromazine, and anesthesia was induced with thiamylal and maintained with 1.5 minimal alveolar concentration of MOF or HAL for 1 hour during controlled ventilation. Eight treatments were given with each anesthetic: 3 with MEP (0.5, 1.0, and 2.0 mg/kg, IV), 3 with oxymorphone (OXY; 0.05, 0.1, and 0.2 mg/kg, IV), and 2 placebos with sterile water. Test drugs were given at the end of anesthesia when early signs of recovery were evident. Minimal threshold stimulus/response nociception was assessed by use of an inflatable soft plastic colonic balloon. Blood pressures and pulse rate were measured with a noninvasive monitor. Meperidine and OXY were found to be effective analgesics and could be reversed with naloxone. Intravenous administration of 2.0 mg of MEP/kg provided analgesia for 36 +/- 6 minutes and 39 +/- 15 minutes after MOF and HAL, respectively. In contrast, OXY was effective at all 3 doses with effects of IV administration of 0.2 mg of OXY/kg lasting 154 +/- 13 minutes and 152 +/- 12 minutes, after MOF and HAL, respectively. Analgesia could not be demonstrated after anesthesia for acepromazine, MOF, or HAL. Blood pressure was not changed by either anesthetic nor was it influenced by MEP or OXY. Pulse rate was significantly depressed by the higher doses of OXY following HAL, but was not changed by MEP following either anesthetic.(ABSTRACT TRUNCATED AT 250 WORDS)

Acepromazine↗
PubMed1992

Periodic limb movement disorder is associated with normal motor conduction latencies when studied by central magnetic stimulation--successful use of a new technique.

This study prospectively tested the hypothesis that patients with periodic limb movement disorder (PLMD) have longer motor conduction latencies than normals. Six healthy adults, 13 patients with PLMD, and 8 patients with long-term multiple sclerosis (MS) had recordings of motor conduction latencies during wake and sleep. MS subjects were included only to show that we could detect prolongation of central conduction; nonMS subjects were used to test the hypothesis. Subjects had no other medical or sleep problems. A novel magnetic stimulator, the Cadwell MES-10, was discharged over the vertex and the C7 cervical spine. It triggered compound muscle action potentials that were recorded in the abductor digiti minimi in the hand. The conduction latencies were the total conduction time (TCT), measured vertex to hand, and the peripheral conduction time (PCT), measured C7 to hand. The difference was the central conduction time (CCT). Only TCT could be obtained during sleep. Supporting the use of TCT as an indirect measure of central conduction was that, in all waking subjects, TCT correlated with CCT (r = 0.91, p = 0.001) but not with PCT. Reliabilities during wake and sleep were 0.95 or higher for TCT and PCT measurements. Waking CCT was greater in MS subjects (13.77 milliseconds) than those without MS (9.21 milliseconds), p = 0.001. Sleeping TCT was much less impressive in distinguishing MS subjects [27.08 milliseconds in nonrapid eye movement (NREM) sleep; 28.64 milliseconds in rapid eye movement (REM) sleep] from nonMS subjects (24.45 milliseconds in NREM; 24.84 milliseconds for REM), p = 0.07 for NREM and p = 0.04 for REM.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Parietal bone mobility in the anesthetized cat.

To quantify parietal bone motion in reference to the medial sagittal suture, a newly developed instrument was attached to the surgically exposed skull of anesthetized adult cats. The instrument differentiated between lateral and rotational parietal bone movements around the fulcrum of the suture. Bone movement was produced by external forces applied to the skull and by changes in intracranial pressure associated with induced hypercapnia, intravenous injections of norepinephrine, and controlled injections of artificial cerebrospinal fluid into the lateral cerebral ventricle. Responses varied considerably among test animals. Generally, lateral head compression caused sagittal suture closure, small inward rotation of the parietal bones, increased intraventricular pressure, transient apnea, and unstable systemic arterial blood pressure. Graded increases in intracranial volume produced stepped increases in pressure, lateral expansion at the sagittal suture, and outward rotation of the parietal bones. We attribute variations in animal response largely to differences in intracranial and suture compliance among them. Cranial suture compliance may be an important factor in defining total cranial compliance.

Animals↗
PubMed1991

Morphology and projections of myenteric neurons to colonic fiber bundles of the cat.

Regulation of colon function depends on the location of nerve cell bodies and the distribution of intrinsic nerve fibers in the myenteric plexus. The morphology and projections of myenteric neurons through colonic fiber bundles in cat colon were determined using in vivo retrograde transport of HRP and Fast blue. Myenteric neurons were found to project from at least 5 to 59 mm orad (mean: 42 mm) or aborad (mean: 54 mm) through colonic fiber bundles. Approximately 73% of labelled cells were in ganglia within 2.8 mm of colonic fiber bundles in the axis of circular muscle fibers; none was beyond 7.7 mm. There were 2 soma morphologies. One type (Dogiel type I) had a mean soma diameter of 40.5 microns and had a rough somal surface. There were few if any short, broad dendrites, but its one long process extended to a branch point of an adjacent colonic fiber bundle. The other type (Dogiel type III) had a mean soma diameter of 26.4 microns, had a smooth somal surface and had few if any fine dendrites. It also projected a single long axon to colonic fiber bundles. There were twice as many Dogiel type III neurons. We conclude that myenteric neurons in the cat colon project both orad and aborad over relatively long distances through colonic fiber bundles where they form another intrinsic neuronal connection for the myenteric plexus.

Afferent Pathways↗
PubMed1991

The idea of revolution in the development of nursing theory.

This paper examines Thomas Kuhn's notion that theory develops by means of revolution and its pervasion within nursing theory. Initially, the traditional, cumulative model of theory development is examined and then Kuhn's idea is explored. The extent of its pervasion in nursing theory is outlined. Finally, the value of Kuhn's model of theory development in nursing is evaluated. It is argued that while Kuhn's model has set nursing theory free from logical empiricism, it needs to be understood in conjunction with the traditional cumulative model.

Humans↗
PubMed1991

Effects of P. aeruginosa-derived bacterial products on tracheal ciliary function: role of O2 radicals.

The purpose of this investigation was to evaluate the effects of bacterial products derived from Pseudomonas aeruginosa on the function of airway cilia and to assess the role of phagocytes and oxygen radicals in the observed responses. Ciliary beat frequency (CBF) was measured in a perfusion chamber with a microscopic technique using tracheal epithelial cells obtained from normal sheep by brush biopsy (70% epithelial cells, 18% macrophages, 11% neutrophils). Baseline CBF ranged between 678 and 1,126 min-1. After 20 min of perfusion with the cell free supernatant of P. aeruginosa culture (mucoid strain), a concentration-dependent depression of CBF was observed with a 58% inhibition at a 1:1 dilution (P less than 0.05). The P. aeruginosa-derived products pyocyanin and 1-hydroxyphenazine also decreased CBF in a dose-related fashion. The cilion-inhibitory effects of the supernatant and bacterial products were markedly attenuated after centrifugation of the brush preparation (80% epithelial cells, 16.5% macrophages, 3.5% neutrophils). Glucose/glucose oxidase also caused a rapid, concentration-dependent cilioinhibition or ciliostasis. Catalase blocked or attenuated the ciliary effects of the supernatant, bacterial products and glucose/glucose oxidase. Thus bacterial products released from P. aeruginosa impaired ciliary activity by a pathway which involved neutrophils and was mediated by toxic oxygen radicals.

Animals↗
PubMed1991

A phase I clinical, plasma, and cellular pharmacology study of gemcitabine.

A novel deoxycytidine analog, gemcitabine (2',2'-difluorodeoxycytidine [dFdC]), has been studied in a phase I clinical and pharmacology trial. Doses ranging from 10 to 1,000 mg/m2 were administered over 30 minutes weekly times 3 weeks every 4 weeks. The maximum-tolerated dose (MTD) was 790 mg/m2. The dose-limiting toxicity was myelosuppression, with thrombocytopenia and anemia quantitatively more important than granulocytopenia. Nonhematologic toxicity was minimal. Two responses in patients with adenocarcinomas of the colon and lung were documented. The maximum dFdC plasma concentration, reached after 15 minutes of infusion, was proportional to the total dose administered. Elimination, due mainly to deamination, was rapid (terminal half-life [t1/2], 8.0 minutes) and dose independent. The deamination product 2',2'-difluorodeoxyuridine (dFdU) was eliminated with biphasic kinetics characterized by a long terminal phase (t1/2, 14 hours); it was the sole metabolite detected in urine. The concentration of dFdC 5'-triphosphate in circulating mononuclear cells increased in proportion to the dFdC dose at infusions between 35 and 250 mg/m2. No further increment in dFdC 5'-triphosphate (dFdCTP) was observed at higher doses, which resulted in plasma dFdC concentrations greater than 20 mumol/L (350 to 1,000 mg/m2), suggesting saturation of dFdC 5'-phosphate accumulation. The recommended dose for phase II clinical trials in solid tumors is 790 mg/m2/wk.

Adult↗
PubMed1991

Dose-response of intravenous butorphanol to increase visceral nociceptive threshold in dogs.

This study was designed to determine the effective analgesic dose of butorphanol administered intravenously to obtund visceral nociception, as well as to determine duration of this effect. Additionally, cardiovascular changes and sedative effects were defined. Eight healthy dogs were each given five doses of butorphanol (0.025, 0.05, 0.1, 0.2, and 0.4 mg/kg) plus a sterile water placebo intravenously in a randomized blinded format. Antinociception was assessed using an inflatable Silastic balloon inserted into the colon. Blood pressures and pulse rates were measured with a noninvasive monitor. The greatest efficacy and longest duration of antinociception were produced by 0.4 mg/kg of butorphanol, with a duration of 38 +/- 9 min. Arterial blood pressure and pulse rate did not vary at antinociceptive doses. Mild sedation was observed at all doses, which generally lasted longer than the antinociceptive effects. These data suggest that butorphanol can be given alone intravenously to provide visceral antinociception lasting 30-45 min without significant side effects.

Animals↗
PubMed1991

Dose response to butorphanol administered subcutaneously to increase visceral nociceptive threshold in dogs.

Butorphanol (0.025, 0.05, 0.1, 0.2, 0.4, and 0.8 mg/kg of body weight, and placebo) was given SC to 8 healthy unmedicated dogs to determine its efficacy for visceral analgesia, using a colonic balloon for minimal threshold nociceptor stimulation. Degree of sedation; systolic, diastolic, and mean arterial pressure; and pulse rate were recorded. The highest 3 dosages, 0.2, 0.4, and 0.8 mg/kg, were found to be most effective, with 0.8 mg/kg the only dosage that was significantly different from control responses at the 45-minute interval. Duration of analgesia ranged from 23 to 53 minutes for all 6 dosages and dosing durations were not significantly different from one another. Blood pressures did not change, but pulse rate was significantly decreased by 0.8 mg of butorphanol/kg. We concluded that butorphanol is an effective visceral analgesic of relatively short duration in the dog.

Analgesia↗
PubMed1990

Cholinergic reactivity of tracheal smooth muscle after infection with feline herpesvirus I.

Airway responsiveness was studied in cats 3 or 6 days after exposure to feline herpesvirus I. Control cats were sham inoculated with tissue culture media. Intrathoracic airway caliber was evaluated by pulmonary resistance (RL) and dynamic compliance (Cdyn). Trachealis shortening was quantitated with microfoil strain gauges, which measured the external diameter of tracheal ring 4. Airway smooth muscle contraction was produced using vagal stimulation and local infusion of acetylcholine. The diameter of tracheal ring 4 decreased with increasing frequency of vagal stimulation, and there was more constriction at 3 (PID3) than at 6 days postinfection (PID6) or in control cats. RL increased and Cdyn tended to decrease with increasing frequency of stimulation, but there was no difference between control and infected cats. Infected and control cats did not differ in their response to locally infused acetylcholine. Virus was consistently cultured from conjunctival, nasal, and oral mucous membranes, trachea, and main stem bronchi at PID3 but not from the trachea and main stem bronchi at PID6. Virus was never isolated distal to the main stem bronchi. Tracheal hyperresponsiveness to vagal stimulation correlates with the presence of virus at PID3 and is apparently presynaptic in origin.

Acetylcholine↗
PubMed1990

Clinical study of keratoconus in central Kentucky.

Keratoconus is an ectatic corneal disorder that results in a central or inferior conelike anterior protrusion. This results in irregular myopic astigmatism, causing considerable visual impairment. We have completed a retrospective clinical study of keratoconus in the central Kentucky area. When compared to other national studies of keratoconus, our study patients generally had more severe disease at the time of diagnosis and had a higher rate of keratoplasty. Keratoconus treatment is highly successful, and early diagnosis is warranted to prevent unnecessary visual loss.

Adolescent↗
PubMed1988

A supporting role.

Explore the source record for details and available documents.

Acquired Immunodeficiency Syndrome↗
PubMed1988

The effects of social context and verbal skill on the stereotypic and task-involved behaviour of autistic children.

Twelve autistic children's rates of Stereotypy, Task Involvement and Non Involvement were observed in three settings representing levels of interpersonal contact: Individual Attention, Group Attention and Play. The children were assigned in two groups reflecting high and low verbal skills and overall level of autistic disturbance was used as a covariate. Results showed that the highest levels of Task Involvement and the lowest levels of Stereotypy and Non Involvement were associated with the highest level of interpersonal contact. Verbal skill level predicted higher rates of prosocial behaviour overall, and interacted with the setting measures for Stereotypic behaviours, indicating that the low verbal children tended to self-stimulate most when no demands were made on their behaviour. Implications for further research and educational practice are briefly discussed.

Attention↗
PubMed1988

Physiological, morphological, and histochemical properties of cat external anal sphincter.

The contractile properties, morphology, and the distribution of striated muscle fiber types of the external and sphincter (EAS) were determined using axial force measurements, fiber size cross-sectional area measurements, and histochemistry. Electrical stimulation of motor axons in pudendal nerve at supramaximal intensities (10 V, 0.05 ms duration) elicited twitch contractions of EAS. The time to peak force after a single pulse ranged from 37 to 42 ms. The time for relaxation to half-maximal twitch force ranged from 20 to 29 ms. Repetitive stimulation of motor axons (0.1-3.0 Hz) produced potentiation and fatigue of single twitch contractile force, suggesting that the EAS of the cat is comprised predominantly of fast-twitch muscle fibers. Confirmation of skeletal muscle fiber types was determined by histochemistry. Frozen serial cross sections of EAS were incubated to demonstrate succinic dehydrogenase (SDH) and myosin adenosine triphosphatase after alkaline preincubation (pH 10.4). Based on these reactions, muscle fibers were classified as fast glycolytic (FG) (high ATPase, low SDH), fast oxidative-glycolytic (FOG) (high ATPase, high SDH), and slow oxidative (SO) (low ATPase, high SDH). The mean percentage +/- SE of each histochemical type was the following: FG, 73.5 +/- 3.9; FOG, 22.8 +/- 3.7; and SO, 3.7 +/- 0.6. These results indicate that the predominant fiber type for the EAS is FG. The EAS of the cat is considered a nominally fast-twitch muscle.

Anal Canal↗