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Biomedical subjects

C S Martin

Publications and source records attributed to C S Martin.

At least 73 records · Page 4Linked to original sources
PubMed1991

Sedation for paediatric computerized tomography--a double-blind assessment of rectal midazolam.

This double-blind study investigated the rectal administration of midazolam as an alternative to general anaesthesia for elective computerized tomography (CT) of the brain. Thirty children were randomly allocated to receive either midazolam 0.3 mg kg-1 (Group 1) or midazolam 0.6 mg kg-1 (Group 2) by the rectal route. Sedation was obtained in 13 children in Group 1 and 12 in Group 2 but this was only satisfactory for scanning in seven children in Group 1 and eight in Group 2. We concluded that although the technique produced sedation, it did not reliably produce satisfactory conditions for CT scanning.

Administration, Rectal↗
PubMed1990

Identification of nonalcoholic and alcoholic beers: effects of consumption practices and beer brand.

Because nonalcoholic beer provides sensory cues that simulate alcoholic beer, this beverage may be more effective than other placebos in contributing to a credible manipulation of expectancy to receive alcohol. The present experiment assessed the sensory identification of nonalcoholic and alcoholic beers. Subjects with higher beer consumption practices were more accurate than subjects with lower beer consumption practices in the identification of nonalcoholic beers. Brand of nonalcoholic beer affected the identification performance of subjects with lower beer consumption practices.

Adult↗
PubMed1990

Personality risk and alcohol consumption: a latent variable analysis.

Several studies report modest correlations between measures of personality and measures of alcohol consumption. These results have led many to conclude that the relation between personality characteristics and drinking is weak, and that studying such a relation may not be fruitful. Nevertheless, the magnitude of the correlations between measures of certain personality characteristics and drinking may be attenuated due to the imperfect reliability of the measures. By viewing specific measures of personality, and alcohol consumption as fallible indicators of underlying constructs, and using confirmatory factor analysis to estimate the relation between them, a correlation of .80 was found, implying that the relation between personality and drinking may be stronger than correlational analyses suggest.

Alcohol Drinking↗
PubMed1990

The malpractice morass and practice activities of orthodontists.

This study examined the association between malpractice, measured by perception and experience scores, and practice activities of orthodontists. Data from 184 Florida orthodontists were obtained in the form of continuous/ordinal responses to survey questions in five areas: demographic, work load, personality, perception of the malpractice environment, and practice activities (malpractice experience, record taking, disclosure, and rapport). Mutually exclusive recency categories were selected on the basis of when an activity was last performed. Descriptive statistics and plots of the data were examined. A malpractice experience score for each respondent was determined by means of factor analysis procedures on the activity question responses. The association between perception/experience scores and responses to activity, demographic, work load, and personality questions were examined with the use of stepwise multiple regression procedures. The results indicated that practice activities, in the areas of record taking and doctor-patient rapport, were moderately associated with both experience scores (R2 = 0.47, p = 0.08) and perception scores (R2 = 0.29, p less than 0.06). Perception of the malpractice environment was associated with practice activities of orthodontists but to a lesser extent than active experiences in that environment were.

Dental Records↗
PubMed1990

Ascending and descending rates of change in blood alcohol concentrations and subjective intoxication ratings.

Subjective feelings of intoxication help determine drinking-related behavior. Most experiments in this area have examined levels of intoxication at different blood alcohol concentrations (BACs) rather than the rate of change of these variables over time. In the present experiments, the rate of change of BACs and of intoxication ratings were compared on both the ascending and the descending limbs of these variables after alcohol challenge. BACs and intoxication ratings reached peak values at the same time when alcohol consumption took 55 min. However, when consumption was rapid (10 min), intoxication ratings reached peak values earlier than did BACs. In both experiments, intoxication ratings returned to baseline sooner than did BACs. The results suggest that internal cues to the effects of alcohol decline rapidly on the descending limb of the blood alcohol curve. The present methodology provides a way to compare the rate of change of variables with different measurement scales.

Adult↗
PubMed1990

Extradural methadone and bupivacaine in labour.

We performed a double-blind placebo-controlled study of the effects of extradural administration of methadone 5 mg or saline, followed by bupivacaine, in 42 women in early labour. Motor block and pain scores were significantly less in the methadone group. The requirement for bupivacaine also was reduced by methadone, but this was not statistically significant. There were no troublesome side effects attributable to methadone.

Adult↗
PubMed1990

Recurrent bronchospasm during anaesthesia.

Bronchospasm complicated several anaesthetics in a diabetic patient with chronic renal failure. The bronchospasm was accompanied frequently by bradycardia. The pathophysiology, treatment and implications for future anaesthetic management are discussed.

Adult↗
PubMed1990

The Michigan Alcoholism Screening Test: false positives in a college student sample.

The Michigan Alcoholism Screening Test (MAST), designed and validated by Selzer (1971), is widely used to screen for persons with alcohol problems. The most recent version of the MAST includes the question "Have you ever attended a meeting of Alcoholics Anonymous (AA)?" This question may contribute to false positive identifications, as it does not specify whether attendance is for the subject's own problem drinking. In the current research, 114 college students completed the MAST along with an additional question: "Have you ever attended a meeting of Alcoholics Anonymous because of your own problem drinking?" The results indicated that seven of 114 subjects (6.1%) attained inflated MAST scores because they had attended an Alcoholics Anonymous meeting, but not for their own problem drinking. It is suggested that the wording to the Alcoholics Anonymous question on the MAST be changed to reduce the number of false positive identifications produced by this instrument.

Adult↗
PubMed1990

Some boundary conditions for effective use of alcohol placebos.

The present research assessed the conditions under which subjects who consume alcohol and those who consume a placebo beverage, and who report consuming alcohol on a manipulation check question, are equivalent with respect to subjective responses to alcohol. Male subjects were told that they were drinking alcohol and consumed one of four beverages: alcoholic beer, nonalcoholic beer, vodka and tonic with lime, or tonic with lime. Measures of subjective intoxication, body sensations and breath alcohol were taken at different times during and after beverage consumption. Subjective intoxication ratings were higher for subjects who received alcohol, compared to subjects who received a placebo and reported consuming alcohol, when alcohol subjects achieved blood alcohol concentrations at and above .04%. These two groups did not differ in subjective intoxication ratings when alcohol subjects achieved blood alcohol concentrations below .04%. These data suggest that the orthogonal manipulation of alcohol consumption and expectancy effects is problematic at and above blood alcohol concentrations of .04%.

Adult↗
PubMed1989

Effects of talker variability on recall of spoken word lists.

Three experiments were conducted to investigate recall of lists of words containing items spoken by either a single talker or by different talkers. In each experiment, recall of early list items was better for lists spoken by a single talker than for lists of the same words spoken by different talkers. The use of a memory preload procedure demonstrated that recall of visually presented preload digits was superior when the words in a subsequent list were spoken by a single talker than by different talkers. In addition, a retroactive interference task demonstrated that the effects of talker variability on the recall of early list items were not due to use of talker-specific acoustic cues in working memory at the time of recall. Taken together, the results suggest that word lists produced by different talkers require more processing resources in working memory than do lists produced by a single talker. The findings are discussed in terms of the role that active rehearsal plays in the transfer of spoken items into long-term memory and the factors that may affect the efficiency of rehearsal.

Adult↗
PubMed1989

Joint angle feedback and biomechanical gait analysis in stroke patients: a case report.

The purpose of this case report is to demonstrate the use of gait analysis and computer-assisted visual and auditory feedback (CAF) in the treatment of a patient with stroke secondary to hemiplegia. Two-dimensional kinematic and kinetic gait analyses were performed to determine the objectives of treatment and to evaluate the results. The CAF hardware and software permitted immediate visual feedback of performance relative to the desired target with auditory reinforcement if the target was reached in the desired phase of the gait cycle. The objective of the treatment was to increase knee flexion during push-off and pull-off. After four weekly treatments, the patient's gait velocity and stride length, in addition to transfers between kinetic energy and potential energy, were significantly improved. The patient demonstrated a downward trend in total mechanical energy costs and an upward trend in the amount of energy conservation, as well as increased knee flexion. These promising results indicate a need for further research into the use of CAF as a tool in motor learning for rehabilitation.

Ankle Joint↗
PubMed1989

Effects of alcohol on the acoustic-phonetic properties of speech: perceptual and acoustic analyses.

This report summarizes the results of a series of studies that examined the effects of alcohol on the acoustic-phonetic properties of speech. Audio recordings were made of male talkers producing lists of sentences under a sober condition and an intoxicated condition. These speech samples were then subjected to perceptual and acoustic analyses. In one perceptual experiment, listeners heard matched pairs of sentences from four talkers and were required to identify the sentence that was produced while the talker was intoxicated. In a second perceptual experiment, Indiana State Troopers and college undergraduates were required to judge whether individual sentences presented in isolation were produced in a sober or an intoxicated condition. The results of the perceptual experiments indicated that groups of listeners can significantly discriminate between speech samples produced under sober and intoxicated conditions. For acoustic analyses, digital signal processing techniques were used to measure acoustic-phonetic changes that took place in speech production when the talker was intoxicated. The results of the acoustical analyses revealed consistent and well-defined changes in speech articulation between sober and intoxicated conditions. Because speech production requires fine motor control and timing of the articulators, it may be possible to use acoustic-phonetic measures as sensitive indices of sensory-motor impairment due to alcohol consumption.

Adult↗
PubMed1989

Some effects of talker variability on spoken word recognition.

The perceptual consequences of trial-to-trial changes in the voice of the talker on spoken word recognition were examined. The results from a series of experiments using perceptual identification and naming tasks demonstrated that perceptual performance decreases when the voice of the talker changes from trial to trial compared to performance when the voice on each trial remains the same. In addition, the effects of talker variability on word recognition appeared to be more robust and less dependent on task than the effects of word frequency and lexical structure. Possible hypotheses regarding the nature of the processes giving rise to these effects are discussed, with particular attention to the idea that the processing of information about the talker's voice is intimately related to early perceptual processes that extract acoustic-phonetic information from the speech signal.

Adult↗
PubMed1983

Total thymectomy in the early chick embryo.

A new microsurgical procedure is described through which the thymus can be completely removed bilaterally prior to its seeding by lymphoid precursor cells in the chick embryo. 53% of the embryos operated at 5 days of incubation and sacrificed either before or after hatching were totally thymectomized as controlled on serial sections of the neck. Hatchability is low, as it normally is when operations are performed on embryos in ovo. However totally thymectomized viable chicken could be recovered. In certain series of experiments, the graft of a 5-day quail embryonic thymus was performed into the site of excision of the chick thymus. The quail thymic rudiment then became colonized by chick lymphoid precursor cells and developed normally. The possibility of using this excision-graft technique is suggested to study the role of MHC gene products in T-cell differentiation.

Animals↗
PubMed1981

Transcutaneous noninvasive monitoring of carbon dioxide tension.

We evaluated the accuracy of a new device for continuous noninvasive measurement of cutaneous PCO2. The Hewlett-Packard capnometer (model 47210/HA) works by means of an infrared transducer applied to the forearm over an area of skin that has been stripped of the stratum corneum. Capnometer transcutaneous carbon dioxide pressure (CPCO2) was compared with arterial carbon dioxide pressure (PaCO2) during 60 simultaneously obtained measurements in 13 hemodynamically stable patients. Each patient was studied for 1 1/2 to 5 hours, and a wide range of PaCO2 values (21 to 82 mm Hg) was represented. The data show a clinically significant relationship whereby PaCO2 = CPCO2 - 4.13, with a SE of +/- 2.19 mm Hg. Clinical usefulness of noninvasive cutaneous CO2 monitoring can be foreseen in patients whose ventilatory support is being tapered, in those with respiratory depression caused by various neuromuscular disorders, and in patients with chronic obstructive pulmonary disease and acute respiratory failure. Our results indicate that continuous transcutaneous CPCO2 measurements are safe and accurate and strongly suggest that they can be of clinical usefulness in a select group of hemodynamically stable patients.

Adult↗
PubMedDate not supplied

Imaging of chemiluminescent signals with cooled CCD camera systems.

We investigated imaging of chemiluminescent signals from 1,2-dioxetanes with cooled CCD cameras. Non-radioactive detection methods for biomolecules utilizing these chemiluminescent substrates for alkaline phosphatase have been developed. Applications which have been successfully adapted to this technology include Southern and Northern blotting, immunoblotting, ELISA methods and DNA sequencing. Dephosphorylation of the dioxetane CSPD by alkaline phosphatase generates an unstable anion that decomposes resulting in light production. The wavelength of the emitted light is approximately 460 nm. We have utilized Photometrics Star and MXC 200L cooled CCD cameras for direct imaging of chemiluminescent signals. Benefits of utilizing a CCD detector include rapid data digitization and more accurate quantitation of chemiluminescent signals compared to film-based densitometry owing to the significantly greater dynamic range. Chemiluminescent images from dot blots of biotinylated DNA, Southern blots and DNA sequencing gel blots were obtained. In a chemiluminescent microtitre plate assay, serial dilutions of alkaline phosphatase spanning four orders of magnitude can be detected. Our results indicate that the digitization of chemiluminescent signal data with cooled CCD cameras is an excellent alternative to 32P detection methods utilizing storage phosphor screen imaging systems.

Base Sequence↗