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Biomedical subjects

R Guest

Publications and source records attributed to R Guest.

17 recordsLinked to original sources
PubMed2000

Computer recording of standard tests of visual neglect in stroke patients.

OBJECTIVE: To determine whether a computer-based method for recording standardized assessment of neglect identifies abnormalities in the 'process' as well as in the 'outcome' of such tasks. DESIGN: Prospective sequential assessment of patients admitted to a stroke rehabilitation unit. SUBJECTS: All consecutive patients with right-sided cerebrovascular accident confirmed on computerized tomography (CT) scan including 30 patients with neglect, 57 patients without neglect. An age-matched control group of 13 subjects. INTERVENTION: All patients were tested using the standard Rivermead Behavioural Inattention Test (BIT) and by computer recording of two standard tests for assessing neglect (line bisection and Albert's test). Age-matched controls were tested using computer recording of the two standard tests. MAIN OUTCOME MEASURES: Neglect was defined using the BIT with a cut-off score of 129. Computer recording measured the 'outcome' of tasks, i.e. the deviation from midline and omissions in cancellation, as well as the 'process' of tasks, i.e. time between cancellations, components of cancellation time including premovement, movement and drawing time, and the starting point for cancellation. RESULTS: The computer recording identified significant differences in 'outcome' and 'process' which distinguished neglect from non-neglect patients. There were significant differences between non-neglect patients and age-matched controls with regard to 'process' measures but not with regard to 'outcome' measures. CONCLUSIONS: Computer recording of standard tests for assessing neglect identifies novel impairments with regard to the process of carrying out tasks. These impairments may be used to investigate changes in neglect with time, the response of neglect to treatment and to explore further the neuropsychological changes associated with neglect in stroke patients.

Aged↗
PubMed1999

Developing algorithms to enhance the sensitivity of cancellation tests of visuospatial neglect.

We describe a set of algorithms that enhance the sensitivity of cancellation tests used in assessing visuospatial neglect. The algorithms can be readily implemented on a computer and can provide temporal and nontemporal data on strategies used during cancellation. We also present preliminary results from a group of 68 right-hemisphere brain-damaged patients and 12 age-matched control participants, which demonstrate the clinical significance of the measures we have defined.

Adult↗
PubMed1997

Relationships of oxygen uptake, heart rate, and ratings of perceived exertion in persons with paraplegia during functional neuromuscular stimulation assisted ambulation.

Previous reports have described significant limitations in the daily use of functional neuromuscular stimulation (FNS) ambulation systems by persons with spinal cord injuries (SCI). The potential application of these devices to provide physiological benefits as an exercise modality has prompted a reconsideration of the technology. However, the acute physiological effects related to the use of FNS systems have not been thoroughly examined. The purpose of this study was to investigate the relationships of oxygen consumption (VO2), heart rate (HR), and ratings of perceived exertion (RPE) during FNS ambulation by persons with SCI paraplegia. Eleven persons with thoracic level paraplegia, aged 21.5 to 38.0 years, participated in an incremental FNS ambulation test. Metabolic measures were collected continuously via open circuit spirometry as the subjects performed a series of ambulation passes of progressively increasing pace. At the end of each ambulation pass, HR and RPE measures were collected. The test was terminated when either the subjects judged the effort to be maximal or when the investigators deemed the effort to be maximal based on HR. A strong linear relationship was documented between the VO2 and HR measures of all subjects throughout subpeak levels of FNS ambulation. RPE did not vary proportionally with VO2 until relatively high levels of exercise intensity were reached. This study indicates that HR, but not RPE, is an appropriate indicator of exercise intensity for persons with SCI paraplegia using a FNS ambulation system.

Adult↗
PubMed1991

Clean rooms and itchy faces.

Seventy-one male employees whose working environment was a temperature and dust controlled low-humidity 'Clean Room' and 144 male employees working in a natural factory environment were compared by means of period percentage prevalences of occurrence, severity and frequency of subjective symptoms of facial dermatitis. Using a cross-sectional interviewer-administered questionnaire it was possible to assess the percentage prevalence of each of 3 facial dermatitis symptoms among both low humidity exposed and non-exposed workers. The two prevalences were compared by calculating a ratio (the percentage prevalence ratio or PPR) of the prevalence of symptoms in the exposed, to that in the non-exposed workforce. A confidence interval (CI) for the PPR was also calculated. For the symptom of itching, the PPR was 1.65 (CI 1.32-2.07) in favour of the study group, whilst for the symptoms of redness and urticaria the PPRs were 1.96 (CI 1.54-2.48) and 2.53 (CI 1.40-4.59) respectively. The occurrence of a greater prevalence of all symptoms in the low-humidity exposed workforce confirms the clinical and laboratory reports of previous workers. A comparison was also made between the two groups of workers of both the severity, and the frequency of occurrence of symptoms. Whilst there was no statistically significant difference between the exposed and non-exposed groups for prevalence of one symptom, among those who had experienced two symptoms there was a PPR of 2.43 (CI 1.37-4.30) between the two groups. Furthermore, among those workers who had experienced all 3 symptoms of facial dermatitis there was a PPR of 3.38 (CI 1.18-8.93) in favour of the low-humidity exposed workforce.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Extra-alveolar veins are contiguous with, and leak fluid into, periarterial cuffs in rabbit lungs.

We previously observed physiological evidence that arterial and venous extra-alveolar vessels shared a common interstitial space. The purpose of the present investigation was to determine the site of this continuity to improve our understanding of interstitial fluid movement in the lung. Orange G and Evans blue dyes were added to the arterial and venous reservoirs, respectively, of excised rabbit lungs as they were placed 20 cmH2O into zone 1 (pulmonary arterial and venous pressures = 5 cmH2O, alveolar pressure = 25 cmH2O). After 10 s or 4 h the lungs were fixed by immersion in liquid N2, freeze-dried, cut into 5-mm serial slices, and examined by light macroscopy. Serial sections of 0.25-0.5 mm were subsequently examined by scanning electron microscopy. In the animals subjected to the zone 1 stress for 4 h, arterial and venous extra-alveolar vessels were surrounded by cuffs of edema. The edema ratio (cuff area divided by vessel lumen area) was greater around arteries than veins and decreased with increasing vessel size. Periarterial cuffs usually contained orange dye and frequently contained both orange and blue dye. Lymphatics containing orange or blue dye were frequently seen in periarterial cuffs. Scanning electron microscopy demonstrated that extra-alveolar veins of approximately 100 microns diameter were anatomically contiguous with arterial extra-alveolar vessel cuffs. In rabbit lungs, both arterial and venous extra-alveolar vessels (and/or alveolar corner vessels) leak fluid into perivascular cuffs surrounding arterial extra-alveolar vessels, and lymphatics located in the periarterial cuff contain fluid that originates from both the arterial and venous extra-alveolar vessels.

Air Pressure↗
PubMed1990

Respiratory ill-health in dental laboratory technicians: a comparative study of GP consultation rates.

Eighteen Royal Air Force dental laboratory technicians (DLTs) and 69 Service controls matched for age, sex and smoking status were compared by means of incidence rates of GP consultation for respiratory, and all other, illness. By retrospectively calculating for each individual the time served (man-years at risk) at the RAF Station concerned, together with the number of consultations that fell into each of the study categories, it was possible to produce an incidence rate, per man-year at risk, of consultations for both study and control groups. By calculating a relative risk (RR) it was observed that DLTs were nearly three times (RR = 2.95. CI 1.69-5.13), more likely to attend their GP with respiratory problems than members of the control group, and 1.7 times (RR = 1.71. CI 0.98-3.01) more likely to attend their GP with other problems. Comparison of the numbers of individuals continuing to use bronchodilator therapy in each of the two groups suggested that DLTs have a higher prevalence of conditions that require this form of therapy as treatment.

Adult↗