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Biomedical subjects

C A Roberts

Publications and source records attributed to C A Roberts.

At least 55 records · Page 3Linked to original sources
PubMed1997

Effect of changes in respiratory blood parameters on equine red blood cell K-Cl cotransporter.

K influx into equine red blood cells (RBCs) was measured using 86Rb as a tracer for K under conditions designed to mimic the changes in respiratory blood parameters that occur in vivo during strenuous exercise. The effects on K influx of physiological changes in pH, cell volume, O2 tension (PO2), CO2 tension (PCO2), and bicarbonate and lactate concentrations were defined. Physiological PO2 exerted a dominant controlling influence on the H(+)-stimulated Cl-dependent K influx, consistent with effects on the K-Cl cotransporter, PO2 required for half-maximal activity was 37 +/- 3 mmHg (4.9 kPa). Although RBCs were swollen at low pH, results showed explicitly that the volume change per se had little effect on K influx. Lactate had no effect on volume- or H(+)-stimulated K influxes, nor did bicarbonate or PCO2 affect the magnitude of K influxes after these stimuli or after treatment with protein kinase/phosphatase inhibitors. These results represent the first detailed report of O2 dependence of H(+)-stimulated K-Cl cotransport in RBCs from any mammalian species. They emphasize the importance of PO2 in control of RBC K-Cl cotransport.

Animals↗
PubMed1996

Brief communication: when Adam delved ... an activity-related lesion in three human skeletal populations.

A rare, activity-related lesion, the clay-shoveller's fracture, was identified during osteological analysis in three human populations dating from the Roman to the later Medieval period in England, circa fourth to 14th centuries A.D. The prevalence of this fracture in these populations suggests an osteological indicator for several possible manual activities, but also one that may be the result of a long-standing human subsistence adaptation requiring digging in the soil. Since males as opposed to females appear to be preferentially affected, the occurrence of such injuries has the potential to provide an insight into the sexual division of labor in earlier human populations.

Adult↗
PubMed1996

Paleoepidemiology, healing, and possible treatment of trauma in the medieval cemetery population of St. Helen-on-the-Walls, York, England.

Traumatic lesions are commonly found in the archeological record and have potential to provide insight into the lives of past populations. This paper examines patterns of long bone fractures in the British medieval population of St. Helen-on-the-Walls from York (approximately 1100-1550) in an effort to determine patterns of healing and evidence for treatment. Long bones were macroscopically and radiologically examined. Clinical data were used to assess whether a fracture had successfully or unsuccessfully healed. The results indicate that fractures of the radius and ulna were most common. Males displayed more fractures than women. Most fractures were healed, well aligned, and without substantial deformity. Lack of evidence for deformity in bones likely to be severely affected by fracture implied that immobilization and possibly reduction was practiced on even the poorest residents of the medieval city.

England↗
PubMed1996

Translocation (X;18) in primary synovial sarcoma of the lung.

Primary sarcomas of the lung are extremely rare. Among the most common to occur in this location are leiomyosarcoma, fibrosarcoma, and hemangiopericytoma. Many difficulties are encountered when establishing these sarcoma diagnoses, or one of another pathologic type, because of overlapping histologic features and morphologic similarities between primary and metastatic lesions. In this study, the diagnosis of a primary monophasic synovial sarcoma of the lung was aided by the observation of the X;18 translocation characteristic of this neoplasm. To the best of our knowledge, this is the first cytogenetic report of a primary pulmonary synovial sarcoma.

Chromosomes, Human, Pair 18↗
PubMed1996

Effects of ozone and airway inflammation on glutathione status and iron homeostasis in the lungs of horses.

OBJECTIVE: To investigate the effects of ozone and airway inflammation on indices of oxidant injury in horses. ANIMALS: 5 clinically normal horses and 25 horses referred for poor performance. PROCEDURE: Blood, tracheal wash, and bronchoalveolar lavage fluid samples were collected before and after ozone exposure (n = 5) or from clinical cases (n = 25), and were analyzed for reduced glutathione (GSH), glutathione disulfide (GSSG), and free and total iron (Fe) values. A scoring system (0 to 5) was used to assess airway inflammation on the basis of clinical signs and cytologic analysis of the tracheal wash and bronchoalveolar lavage fluid samples. RESULTS: Ozone induced significant (P < 0.05) increases in GSH (195.4 +/- 68.5 microM), GSSG (19.4 +/- 6.4 microM), and free (25.5 +/- 16.1 microM) and total (93.1 +/- 13.4 microM) Fe values in the pulmonary epithelial lining fluid, compared with preozone samples (49.2 +/- 18.6, 2.4 +/- 1.2, 0.0, and 33.1 +/- 5.9 microM, respectively). The presence of airway inflammation (19/25) was associated with high GSSG and free and total Fe, but not GSH, values in epithelial lining fluid, compared with values for clinically normal horses (6/25). There were no differences in the systemic values of GSH, GSSG, and free and total Fe between any of the groups. A strong correlation (r = 0.84; P < 0.001) existed between inflammation score and the glutathione redox ratio (GSSG/[GSH + GSSG]) in the 25 horses admitted for clinical examination. CONCLUSIONS: Oxidant injury in the lung will induce changes in the glutathione status and Fe homeostasis that could affect pathogenesis of the disease. CLINICAL RELEVANCE: Measurement of indices of oxidant injury may be useful in the diagnosis of airway inflammation and the response to inhaled oxidants.

Animals↗
PubMed1996

Physiological responses in nonheat acclimated horses performing treadmill exercise in cool (20 degrees C/40% RH), hot dry (30 degrees C/40% RH) and hot humid (30 degrees C/80% RH) conditions.

The aim of the present study was to determine the effect of different environmental conditions on physiological response to exercise. Four winter acclimatised, nonheat acclimated horses of different breeds were exercised at 20 degrees C/40% RH (CD), 30 degrees C/40% RH (HD) and 30 degrees C/80% RH (HH). The exercise test was designed to represent the structure and intensity of a One star Speed and Endurance test (competition exercise test [CET]). All 4 horses were able to complete the full CET (60 min + 30 min active recovery) in CD and HD, but only one horse completed the CET in HH. Two horses were stopped because of pronounced general fatigue and one because of a right atrial temperature (TRA) of 43 degrees C. Oxygen uptake on each phase was not different between CD and HD, but was higher during Phases B, C and D in HH. Mean peak TRA at the end of Phase D was 40.3 +/- 0.2, 41.6 +/- 0.4 and 42 +/- 0.3 degrees C for CD, HD and HH, respectively. Corresponding, mean peak rectal temperatures (TREC) following Phase D were 39.5 +/- 0.1, 40.6 +/- 0.1 and 41.5 +/- 0.1 degree C for CD, HD and HH, respectively. Mean time to peak TREC was 9.3 +/- 1.1 (CD), 7.3 +/- 1.8 (HD) and 10.8 +/- 2.3 (HH) min and was not significantly different between conditions (P > 0.05). Heat dissipation amounted to 83 +/- 1, 73 +/- 2 and 70 +/- 1% of heat production in CD, HD and HH, respectively. Weight loss was significantly correlated with both body surface area (CD r = 0.85; HD r = 0.87; HH r = 0.81) and bodyweight (CD r = 0.97; HD r = 0.93; HH r = 0.94). The greatest weight loss recorded was 4.6% bodyweight in one horse in HD. The mean increase in exercise intensity over the whole CET (in terms of VO2) of HD and HH and HH compared with CD was 5 +/- 3 and 14 +/- 3% higher, respectively. The exercise induced hyperthermia and the reduced capacity for heat dissipation produced partial compensatory responses in minute ventilation (VE), particularly during Phase C, when the horses were trotting. In HD, the increase in VE was achieved mainly through an increase in frequency, whilst in HH it was achieved through an increase in tidal volume (VT). The horses demonstrated a high degree of tolerance to environmental heat load, suggesting a high thermoregulatory capacity. However, for unacclimatised animals exercising in severely hot and humid conditions, performance may be limited.

Acclimatization↗
PubMed1995

Maxillary sinusitis in Medieval Chichester, England.

Maxillary sinusitis is a common medical complaint, affecting more than 30 million people per year in the United States alone. Very little palaeopathological work on this disease has been carried out, probably because of the enclosed nature of the sinuses in intact skulls and the lack of a suitable method for examination. This study tested the hypothesis that maxillary sinusitis was more common in people with leprosy than in people without it in Medieval England. The prevalence of maxillary sinusitis by age and sex was recorded in 133 individuals, some diagnosed as being leprous, derived from a later Medieval (12th to 17th centuries AD) urban hospital population at Chichester, Sussex, England using both macroscopic and endoscopic methods of examination. Of the 133 individuals with one or both sinuses available for examination, 54.9% (73) had evidence of bone change within the sinuses. There was no difference in prevalence between those with leprosy and those without, although clinical studies suggest that over 50% of lepromatous leprous individuals may develop sinusitis. Comparison with another study on Medieval British sites with a 3.6% prevalence (3 of 83) indicates that the prevalence at Chichester is much greater. The problems with diagnosing sinusitis are addressed and reasons behind the high frequency in this study are discussed. Aetiological factors predisposing to maxillary sinusitis are considered with reference to possible environmental conditions prevailing in the later Medieval period in Britain.

Bone and Bones↗
PubMed1995

Comparative study of the prevalence of maxillary sinusitis in later Medieval urban and rural populations in northern England.

Six hundred sixty-three Medieval individuals from Wharram Percy, a rural settlement in the Yorkshire Wolds, and 1,042 individuals from St. Helen-on-the-Walls, a poor parish in the Medieval city of York, were examined in order to test the hypothesis that maxillary sinusitis would be more prevalent in an urban population due to social and environmental conditions characteristic of an industrialized settlement. The results showed that the individuals from St. Helen-on-the-Walls, living in the urban environment, had a greater prevalence of maxillary sinusitis than the rural population; 39% (106) of the individuals from Wharram Percy had evidence of sinusitis compared to 55% (134) of the individuals from St. Helen-on-the-Walls. It is suggested that this pattern may be attributed to occupation and industrial air pollution in the Medieval city of York.

England↗
PubMed1995

Modulation by "central" PCO2 of the response to carotid body stimulation in man.

We describe a method to assess the effects of PCO2, around and below eucapnia, on the neuromuscular ventilatory response to a standard peripheral chemoreceptor stimulus. Subjects were "passively" hyperventilated (without respiratory muscle activity), at a constant level of ventilation. Stimuli (3-7 breaths N2) were delivered over a range of steady-state PETCO2 (25-43 mmHg). Stimuli during hypocapnia were coupled with a transient increase in FICO2 so that the stimulus to the peripheral chemoreceptors was always "hypoxia at eucapnia". Responses to the stimuli (quantified from the reduction in peak inflation pressure and the magnitude of the evoked diaphragm electromyographic activity) decreased in a graded manner as steady-state PETCO2 fell, disappearing at 7.5 mmHg below eucapnia. Carotid body chemoreceptor recordings from two anaesthetised cats, indicated that the peak firing rate during such stimuli was independent of steady-state PETCO2. The results suggest that the central sensitivity to a peripheral chemoreceptor input may be modulated by changes in steady-state PCO2 around eucapnia and during mild hypocapnia.

Adult↗
PubMed1995

Physiological, metabolic and biochemical responses of horses competing in the speed and endurance phase of a CCI*****3-day-event.

The present study was undertaken to investigate physiological, metabolic, haematological and biochemical changes in horses competing in the Speed and Endurance test of a Concours Complet International (CCI)*****3-day-event held under FEI rules. A total of 28 horses competing in the Burghley Horse Trials Speed and Endurance test were selected to be monitored: 11 horses in 1993 and 17 horses in 1994. Of the 28 horses selected, 17 completed the Speed and Endurance test and went on to complete the showjumping test. Mean +/- s.d. shade temperature and relative humidity, black globe temperature and wind speed were 13 +/- 1 and 20 +/- 2 degrees C, 54 +/- 3 and 55 +/- 10%, 17 +/- 2 and 29 +/- 4 degrees C and 2.7 +/- 0.7 and 1.2 +/- 0.3 m/s, for 1993 and 1994, respectively. Mean heart rate during Phases A, B and D was not significantly different between years, but mean heart rate during Phase C and X was significantly higher in 1994. Mean (+/- s.d.) heart rate on Phase B and D for all horses in both 1993 and 1994 was 198 +/- 8 and 188 +/- 11 beats/min, respectively. Mean heart rate during Phase D showed a poor correlation with mean speed (r = 0.412). Total mean (+/- s.d.) weight loss from the start of Phase A to the end of Phase D was 15.5 +/- 6.1 kg in 1993 and 16.5 +/- 5 kg in 1994 and did not differ significantly between years. Following 14-18 h completion of Phase D, mean bodyweight was not significantly different from that at the start of Phase A in either year. Mean rectal temperature at the end of Phase D was 41 +/- 0.6 degrees C and 41.1 +/- 0.6 degrees C in 1993 and 1994, respectively (P > 0.05). Both the lowest (39.7 degrees C) and highest (41.8 degrees C) rectal temperatures were recorded at the end of Phase D in 1994. Plasma lactate concentrations at the end of Phase D were 8.5-38.5 mmol/l. The highest lactate concentration also coincided with the highest plasma glucose concentration (11.4 mmol/l) as well as the joint fastest time in either year, although overall lactate showed only weak correlations with mean speed on Phase D (r = 0.12, 1993; r = 0.58, 1994). While the Speed and Endurance test at CCI*****level run in a temperate climate presents a considerable challenge to the fitness and ability of the horses competing, the metabolic and physiological changes are not extreme. The majority of horses that finish the test appear to undergo a rapid and considerable degree of recovery and are able to present sound at the final inspection, take part in the showjumping test and complete the competition.

Animals↗
PubMed1995

Prevalence of maxillary sinusitis in leprous individuals from a medieval leprosy hospital.

The maxillary sinuses of 133 skeletons from the medieval hospital of St. James and St. Mary Magdalene, Chichester, England, were analyzed for evidence of sinusitis. Of the sample, 16 individuals were considered to have suffered from lepromatous leprosy and 13 from tuberculoid leprosy. The most common bone change seen within the sinuses was the presence of new bone formation followed by pitting. Bone change was seen in 56.3% (9 of 16) of the individuals with lepromatous leprosy and 54.8% (57 of 104) of nonleprous individuals. These results are not statistically significant. Clinical evidence suggests that one should see a higher frequency in the lepromatous group. Possible explanations of this include environmental factors promoting the spread of droplet infection in an immunosuppressed community, in addition to which the small sample of leprous skeletons may bias the result.

Adult↗
PubMed1995

Inflammatory bone changes in leprous skeletons from the medieval Hospital of St. James and St. Mary Magdalene, Chichester, England.

The extent and location of an inflammatory bone lesion, periostitis, were examined in 50 leprous skeletons from the Chichester cemetery of the Hospital of St. James and St. Mary Magdalene in Sussex, England. Although the presence of periostitis is not pathognomonic of leprosy, it predominantly indicates dermal and neuropathic changes that the patient would have presented in life. The spread of inflammation across the knee joint and the ossification of the interosseous membrane due to inflammation are also suggested.

Bone and Bones↗