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Biomedical subjects

J M Hutchinson

Publications and source records attributed to J M Hutchinson.

At least 19 recordsLinked to original sources
PubMed2003

Influence of population density on antibiotic resistance.

Antibiotic consumption and population density as a measure of crowding in the community were related to the prevalence of antibiotic resistance of three cities in three different countries: St Johns in Newfoundland (Canada), Athens in Greece and Groningen in The Netherlands. Antibiotic consumption was expressed in DDD (defined daily dose), as DID (DDD/1000 inhabitants/day) and as DSD (DDD/km(2)). The prevalence of antibiotic-resistant Escherichia coli and enterococci was determined in faecal samples of healthy volunteers. In both Newfoundland (28 DID) and Greece (29 DID) the overall consumption of antibiotics was more than three times higher compared with that of The Netherlands (9 DID). The lowest prevalence of resistant E. coli against the majority of antibiotics tested was found for the samples from Newfoundland and was significant (P < 0.05) for cefazolin, oxytetracycline and trimethoprim. A poor correlation between the number of DID and the prevalence of resistance was observed [the Pearson correlation coefficient (Pcc) ranged between -0.93 and 0.87]. However, when population density was taken into consideration and antibiotic consumption was expressed in DSD, a strong correlation was observed (and Pcc ranged between 0.86 and 1.00). This study suggests that population density is an important factor in the development of antibiotic resistance and warrants special attention as a factor in resistance epidemiology.

Canada↗
PubMed2001

Role of diagnostic labeling in antibiotic prescription.

OBJECTIVE: To evaluate the association between diagnostic labeling of respiratory tract infections (RTIs) and antibiotic prescription rates in family practice. DESIGN: Descriptive analysis of outpatient chart review supplemented by interviews with physicians. Charts of patients attending 73 general practitioners were reviewed between October 1997 and February 1998. Two days of practice were evaluated per physician. SETTING: Urban family practices in greater St John's, Nfld. PARTICIPANTS: Of 96 family physicians contacted, 73 (76%) agreed to participate. MAIN OUTCOME MEASURES: Rates of diagnoses and antibiotic prescriptions for acute infections. Physicians were divided into "low prescribers" and "high prescribers" based on overall rates of prescription to patients with infections. Low prescribers were compared with high prescribers with respect to physician characteristics, patient characteristics, and diagnoses assigned. RESULTS: Of all patients seen, 22% were seen for acute infections; RTIs accounted for 76% of diagnoses. Low prescribers and high prescribers were of similar ages and saw similar numbers of patients of similar ages with very similar presenting complaints. Both groups diagnosed urinary tract and skin and soft-tissue infections at similar rates, but differed markedly in their rates of diagnoses of RTIs. High prescribers diagnosed bacterial RTIs in 65.4% (147/225) of their patients; low prescribers diagnosed bacterial RTIs in 31.0% (66/213 (P < .001). CONCLUSION: Family doctors frequently prescribe antibiotics. The difference in rates of prescription between high prescribers and low prescribers is largely explained by assignment of diagnoses of RTIs.

Acute Disease↗
PubMed2000

Heme oxygenase activity in term human placenta.

Carbon monoxide (CO) is a novel gaseous chemical messenger, formed during heme oxygenase (HO)-catalysed oxidation of heme. CO is proposed to play a key role(s) in cell function in many organ systems, including vasodilator action in the cardiovascular system. Recently, it has been demonstrated that there is expression of HO protein in the human placenta and this appears to have a regulatory role in placental perfusion. The objective of the present study was to determine HO enzymatic activity in vitro in five different regions of term human placenta. HO activity was determined in the microsomal fraction of tissue homogenate by measuring the rate of formation of CO from heme, using a gas-chromatographic method. HO activity, expressed as nmol CO formed/g tissue wet weight/h, was higher (P< 0.05) in the chorionic plate, chorionic villi, basal plate and chorio-decidua compared with the amnion. The finding that HO enzymatic activity is present in different regions of term human placenta supports the concept that the heme-CO (HO) pathway plays a complementary role with the L -arginine-nitric oxide (nitric oxide synthase) pathway in the regulation of placental haemodynamics.

Amnion↗
PubMed1999

Method of physician remuneration and rates of antibiotic prescription.

BACKGROUND: Rates of antibiotic prescription in Canada far exceed generally accepted rates of bacterial infection, which led the authors to postulate that rates of antibiotic prescription depend to some extent on factors unrelated to medical indication. The associations between antibiotic prescription rates and physician characteristics, in particular, method of remuneration and patient volume, were explored. METHODS: The authors evaluated all 153,047 antibiotic prescriptions generated by 476 Newfoundland general practitioners and paid for by the Newfoundland Drug Plan over the 1-year period ending Aug. 31 1996, and calculated rates of antibiotic prescription. Linear and logistic regression models controlling for several physician characteristics, specifically age, place of education (Canada or elsewhere), location of practice (urban or rural) and proportion of elderly patients seen, were used to analyse rates of antibiotic prescription. RESULTS: Fee-for-service payment (rather than salary) and greater volume of patients were strongly associated with higher antibiotic prescription rates. Fee-for-service physicians were much more likely than their salaried counterparts to prescribe at rates above the median value of 1.51 antibiotic prescriptions per unique patient per year. The association between rate of antibiotic prescription and patient volume (as measured by number of unique patients prescribed to) was evident for all physicians. However, the association was much stronger for fee-for-service physicians. Physicians with higher patient volumes prescribed antibiotics at higher rates. INTERPRETATION: In this study factors other than medical indication, in particular method of physician remuneration and patient volume, played a major role in determining antibiotic prescribing practices.

Adult↗
PubMed1995

An intercomparison study of 237Np determination in artificial urine samples.

An intercomparison study of low-level 237Np determination in artificial urine samples has been carried out. The purpose of this study was to find the "optimal" method presently available for use in a routine in-vitro radiobioassay program for occupationally exposed workers. Four synthetic urine samples with differing 237Np concentrations were prepared: (1) 3 mBq kg-1 of 237Np; (2) 3 mBq kg-1 of 237Np with natural uranium, 239Pu and 241Am as interferences; (3) 50 mBq kg-1 of 237Np; and (4) a matrix blank. The solutions were submitted to 10 alpha-particle and 10 inductively coupled plasma-mass spectrometry (ICP-MS) laboratories of which six and four laboratories, respectively, returned results. Two laboratories performed assays using both techniques. The radiochemical method of choice used 239Np as the tracer, which utilized a combination of coprecipitation and anion-exchange separation. The best results obtained by ICP-MS were comparable with but not better than the most accurate results obtained by alpha-particle spectrometry. Alpha-particle spectrometry measurements overall gave consistently better agreement with known values.

Biological Assay↗
PubMed1986

Congenital hypothyroidism missed on screening.

Three patients with congenital hypothyroidism missed on routine screening due to normal low thyrotrophin concentrations in the neonatal period presented in later childhood. Clinicians should remain aware of hypothyroidism as a cause of morbidity in early childhood despite a national screening programme.

Congenital Hypothyroidism↗
PubMed1981

The influence of the onset of phonation on the frequency of disfluency among children who stutter.

This study was designed to assess the effects of on-off voice adjustments on the frequency of stuttering in children. Essentially, this is a replication of the experimental paradigm used by Adams and Reis (1971, 1974) with adult stutterers who were asked to read two passages: one contained a normal distribution of voiced and voiceless sounds; the other contained nearly all voiced sounds. The latter passage was associated with less stuttering and more rapid adaptation. In this study, 15 childhood stutterers in the third through the seventh grades were asked to read these same two passages. Contrary to the previous results with adults, however, the children did not stutter less nor adapt more rapidly with the all-voiced passage. These results are discussed with reference to previous literature and to the influence of pausing.

Child↗
PubMed1981

Verbal transformation patterns in children with articulation defects.

If the motor theory of speech perception is at least partially true, children with articulation problems should do relatively poorly in a typical verbal transformation task. Twelve children aged from 6 yrs 10 mo to 8 years 10 mo with misarticulation of /s/ were compared with 12 matched children with normal speech. Since children with articulation errors have difficulty processing time-compressed speech, the two groups were differentiated also on the basis of a speech discrimination task involving time-compressed stimuli. All Ss listened to three 1-min presentations of the nonsense word /sus/ played repeatedly with a 400-msec interstimulus interval; they pressed one of 4 buttons for each stimulus indicating perception of /sus/, /theta us/, /fus/, and "other." There were fewer transformations for the experimental group and different response profiles for the two groups, suggesting a less mature perception-production linkage in those with articulatory problems.

Association↗
PubMed1980

Acoustic and perceptual evaluation of hypernasality of mentally retarded persons.

Acoustic and perceptual correlates of velopharyngeal competency in two groups of retarded (one Down syndrome, one idiopathic) and one group of nonretarded subjects, equally divided between males and females, was evaluated. There were 20 young adults in each group. Acoustic measures of hypernasality were obtained through analysis by TONAR II. Perceptual judgments were rendered by 15 listeners. Results of perceptual and acoustic analyses revealed that those persons with Down syndrome were significantly more hypernasal than were the other two groups. Those with idiopathic retardation were more hypernasal than were nonretarded subjects.

Adolescent↗
PubMed1978

Patterns of nasalance in a sample of normal gerontologic subjects.

The purpose of this investigation was to evaluate velopharyngeal adequacy in gerontologic subjects using an acoustic analysis strategy. Sixty normal older subjects (30 male, 30 female), ranging in age from 50 to 80, read three passages developed by Fletcher (1976) that differ in number of nasal sounds. In addition, all subjects sustained the vowel /a/. The speech samples were analyzed using TONAR II, which calculates the ratio of nasal sound pressure level to nasal + oral sound pressure level (nasalance). Tonagrams (plots of nasalance over time) were obtained from all subjects. Results demonstrated that older subjects generally evidenced abnormally high nasalance values for the Zoo Passage (contains no nasal sounds). In addition, females exhibited significantly higher nasalance values than males. Inspection of the tonagrams revealed three abnormal acoustic patterns: (1) pervasively high nasalance, (2) momentary loss of velar control, (3) progressive deterioration in velar control. These results are discussed with reference to known neuroanatomical changes associated with advancing age.

Adult↗
PubMed1978

Learning visual correlates of fricative production by normal-hearing subjects: a preliminary evaluation of the video articulator.

This investigation provides a preliminary evaluation of the use of the video articulator, a phonemic recognition device for the hearing impaired. The subjects were five young adults with normal hearing and vision (corrected) who were matched with respect to age, sex, dialect, education, and phonological sophistication. Each subject received 150 min of programmed training to learn the video configurations of the eight English fricatives both in isolation and consonant-vowel contexts. Following the training period, the subjects were given a test to determine adequacy of learning and retention of the video configurations for the training stimuli, in the absence of auditory cues. The subjects' responses were analyzed using a common covariance measure. The results demonstrated generally low transmission values for consonants in isolation. Moreover, identification of consonants in context was less accurate. The subjects, as a group, had greater difficulty in recognizing the productions of other subjects when compared with recognition of their own utterances. The clinical implications of these findings are discussed.

Adult↗
PubMed1976

Jaw mechanics during release of the stuttering moment: some initial observations and interpretations.

As a part of a larger study (Hutchinson and Watkin, 1974), this investigation was undertaken to examine jaw mechanics during the release of stuttering moments. Six adult subjects (four stutters, ranging in severity, and two normal talkers) read a series of sentences containing phonetic sequences requiring jaw depression. Strain-gauge transducers were employed to record articulatory movement. Only those stutterings occurring immediately prior to and during jaw opening were studied. The results confirmed generally faster jaw velocities for the opening and closing gestures; which was interpreted to suggest that the spindle motor system is maximally active to preserve synchrony in on-going vocal tract events following the dysfluency. In cases where an asynchrony between vocalization and jaw opening was noted, it was suggested that imprecision in predicting voice onset resulted in articulatory-laryngeal incoordination. It would appear from these interpretations that the clinical efficacy of the "pull out" procedure results from reduced demands on the gamma loop system and facilitation of articulatory-laryngeal synchrony through reduced supraglottal velocities.

Adult↗