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Biomedical subjects

D S James

Publications and source records attributed to D S James.

33 records · Page 2Linked to original sources
PubMed1993

Sources of variability in posterior rhinomanometry.

Sources of variability in nasal airway resistance measured by posterior rhinomanometry were studied in 5 subjects tested on 5 different days and 56 subjects tested on 2 different days. On each day, a questionnaire on upper airway health and nasal symptoms was completed. The mean individual difference in nasal airway resistance between the 2 test days in the group of 56 subjects was 5.3% (SD 52.7%). Between-subject variability accounted for 74.9% and 72.5% of the total variability in the group of 5 and the group of 56 subjects, respectively. For the 5 subjects, by accounting for a change in upper airway symptoms or upper respiratory tract infection that occurred over the 5 test days, there was a significant decrease in the between-subject variability. The difference in sources of variation due to a change in upper airway symptoms was not seen in the group of 56 subjects. We conclude that the largest source of variability in nasal airway resistance is due to between-subject differences.

Adult↗
PubMed1993

Assessment of heart rate as a predictor of ventilation.

The rate of ventilation and route of breathing (i.e., nasal versus oronasal) are potential determinants of pollutant doses to target sites in the lung. However, the lack of accurate methods for ambulatory measurement of ventilation has hindered estimation of exposure and dose in freely ranging individuals, complicating the interpretation of the relationships among exposure, dose, and response in epidemiological studies. The goal of this project was to develop and validate a method of monitoring ventilation for large-scale epidemiologic investigations. We estimated ventilation for individual subjects from ambulatory heart rate monitoring, using the relationship between ventilation and heart rate that had been obtained during exercise testing. Fifty-eight subjects participated in the study, which included healthy adults and children, and subjects with lung and heart disease. Subjects performed cycle exercise and tasks involving lifting and vacuuming. Work loads of progressive and variable order were used in the testing. Conventional methods were used to measure heart rate and total ventilation, and a sampling mask was developed to measure the partitioning of breathing between oral and nasal routes. The minute ventilation-heart rate relation was evaluated under steady-state and varying work loads. In a second phase, subjects wore wristwatch monitors that recorded their heart rates, minute by minute, throughout the day. Subjects recorded activities, locations, and levels of exertion. Two 16-hour monitoring periods were obtained from each subject. The laboratory findings documented considerable intersubject variability in the minute ventilation-heart rate relation with a two- to five-fold range in the coefficients describing the change in ventilation relative to heart rate. This variation implies that individual testing is required to derive accurate predictive equations. Minute ventilation-heart rate regressions for the maximal progressive exercise test and for the test with a nonprogressive submaximal work load sequence were comparable, indicating that varying the sequence of work loads does not substantially affect the minute ventilation-to-heart rate ratio. During upper body work (e.g., lifting), the minute ventilation-to-heart rate ratio was one-third greater than during lower body exercise. Diverse patterns of partitioning breathing between oral and nasal routes were observed with increasing oral ventilation in most subjects as work load increased. In the field, heart rate and activity patterns were monitored successfully in adults and children with low rates of instrument failure and noncompliance.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1992

Rapid death due to group A streptococcal infections. Necrotizing fasciitis and acute bacterial myositis.

Soft tissue infections due to the group A Streptococcus are difficult to diagnose and rapidly fatal. They may present to the forensic pathologist as an "obscure autopsy". Death may occur within or outside the hospital and with or without a history of fulminant infection or predisposing factors. It is important for the pathologist to exclude this condition through awareness of its existence and by appropriate dissection with retention of materials for microbiological and histological examination.

Adult↗
PubMed1985

Survey of hypnotic drug use in nursing homes.

The prescribing patterns for hypnotic medications were surveyed in 765 patients of three skilled-nursing facilities and two intermediate-care facilities. Seven per cent of the patients received a hypnotic routinely; an additional 3 per cent had as-needed orders for a hypnotic medication. Temazepam, flurazepam, and triazolam were, in descending order, the three most commonly prescribed hypnotics and accounted for 79 per cent of the hypnotic prescriptions. The average duration of use for triazolam, temazepam, and flurazepam was 11 weeks, 24 weeks, and 82 weeks, respectively. Seventy-six per cent of the flurazepam prescriptions were given seven days a week; 31 per cent of these prescriptions were for 30 mg doses. Medications that were not hypnotics but did have sedative side-effects were prescribed with bedtime orders for 11 per cent of the patients. The three most commonly prescribed drugs in this class were diphenhydramine, thioridazine, and haloperidol. Possible explanations for the lower frequency of hypnotic use observed in this study as compared to the frequencies reported in the literature are discussed, as are possible hazards of high-dose and long-term use of hypnotics.

Aged↗
PubMedDate not supplied

Growth and pubertal milestones during adolescence in offspring prenatally exposed to cigarettes and marihuana.

Weight, height, head circumference, and pubertal milestones were examined in one hundred fifty-two 13- to 16-year-old adolescents for whom prenatal exposure to marihuana and cigarettes had been ascertained. The subjects were from a low-risk, predominantly middle-class sample participating in an ongoing, longitudinal study and whose growth has been monitored since birth. The weight of the 13- to 16-year-old children of heavy cigarette smokers, after statistical adjustment, did not differ from control subjects but they had a significantly higher Ponderal Index (PI). These observations continued those noted when these subjects were 9 to 12 years of age. Among the male offspring of cigarette smokers, pubertal milestones occurred at an earlier age than among male adolescents born to nonsmokers. Active smoking by the offspring did not moderate these findings. Maternal marihuana use was not associated with any growth measurement or the timing of pubertal milestones.

Adolescent↗
PubMedDate not supplied

Oronasal distribution of ventilation at different ages.

The route of breathing, oral or nasal, is a determinant of the doses of inhaled pollutants delivered to target sites in the upper and lower respiratory tracts. We measured partitioning of ventilation, using a divided oronasal mask during a submaximal exercise test, in 37 male and female subjects who ranged in age from 7 to 72 y. The following four patterns of breathing were evident during exercise: (1) nasal only (13.5%), nasal shifting to oronasal (40.5%), oronasal only (40.5%), and oral only (5.4%). Children (i.e., 7-16 y of age) displayed more variability than adults with respect to their patterns of ventilation with exercise. Young adults (i.e., 17-30 y of age) who initially breathed nasally with exercise switched to oral ventilation at a lower percentage of the previously measured maximum ventilation (10.8%) than older subjects (31.8%). The partitioning of ventilation between the nasal and oral routes follows complex patterns that cannot be predicted readily by the age, gender, or nasal airway resistance of the subject.

Adolescent↗
PubMedDate not supplied

Limitations of expert evidence.

Doctors from diverse specialties are required, from time to time, to give evidence either in documentary form or in person to both civil and criminal courts. A joint conference of the Royal Colleges of Physicians and Pathologists was held at the Royal College of Physicians on 25 October 1994, with the intention to explore those areas where difficulties might arise for the doctor from either a medical or a legal point of view, both as an informative exercise and in order to identify subjects which might usefully be further examined.

England↗
PubMedDate not supplied

Death certification: is correct formulation of cause of death related to seniority or experience?

We looked at a series of death certificates completed by various grades of hospital clinicians, general practitioners (GPs) and pathologists. Specific error types were defined and identified in each group. In hospital it is still the pre-registration house officer who completes most of the death certificates. Senior hospital doctors make more errors than their juniors while GPs and pathologists make fewest errors. Even amongst pathologists 11% of certificates recorded no adequate underlying cause of death, 85.7% failed to record organisms identified and 76.7% failed to record the site or histological type of tumours. This agrees with other studies that show that inaccuracies in death certificates arise from inadequate formulation of cause of death and failure to record relevant information. It reveals that little heed has been paid to the recommendation in the joint report of the Royal College of Physicians and Pathologists that senior doctors should be more involved in certification--the frequency of errors in this group suggests that it might not, in any case, lead to a great improvement. The number or errors made by GPs and pathologists suggest that even practitioners with clinical experience and regular exposure to certification frequently make errors. The reasons for this are discussed and possible solutions proposed.

Cause of Death↗
PubMedDate not supplied

Detecting homicide in hospital.

The Beverly Allitt case and the subsequent inquiry have focused attention on the detection of covert hospital homicide. Effective investigation can only take place if there is prompt recognition of circumstances that justify suspicion about a death and immediate action is taken to retrieve potentially vital evidence. The hospital itself must take responsibility for the detection of covert homicide. Confidence that such deaths will be uncovered by 'routine' investigation through the existing coroner system, including postmortem examination, is misplaced.

Coroners and Medical Examiners↗
PubMedDate not supplied

The use of personal health information in the coroner's inquiry.

A pathologist appointed by the coroner may feel that his or her role is to review the medical notes, perform a post-mortem, examination and then interpret the findings in the light of clinical information and any other information received from the coroner, and include in the clinico-pathological summary a cause of death. We believe that such an approach is not in accordance with the legal position relating to coroners' inquests. The coroner has no automatic right to see the medical notes (and neither does the coroner's pathologist); where there is, or may be, dispute as to the circumstances leading to death, the proper way for information in the medical record to be presented at the coroner's inquest is for the maker of any note to give oral evidence. Where the cause of death requires interpretation of the clinical history or knowledge of any circumstantial evidence, a pathologist should refrain from giving a cause of death; such a task is for the court, having heard all the evidence-medical or not-relating to the death.

Autopsy↗