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Biomedical subjects

C M Owens

Publications and source records attributed to C M Owens.

At least 19 recordsLinked to original sources
PubMed2003

The validity of sacral ratios to identify sacral abnormalities.

OBJECTIVE: To test the repeatability and validity of a previously described sacral ratio measurement as a method for detecting sacral abnormalities, as the association between sacral abnormalities and neuropathic bladder is well known but the diagnosis of subtle sacral anomalies is often delayed. MATERIALS AND METHODS: Fifty sacral radiographs (from 30 patients with anorectal anomalies and 20 normal children) were viewed and reported as normal or abnormal by an expert spinal radiologist (reference standard). Sacral ratios (anteroposterior, AP, and lateral) were measured while unaware of origin by four investigators and the inter- and intra-observer variability examined. Validity was assessed by comparing individual sacral ratio values with the radiological diagnosis, using Pena's criteria for a normal sacrum (normal >/= 0.74 AP; >/= 0.77 lateral). RESULTS: Sacral ratio estimates were possible in 48 of the 50 selected radiographs. There was good repeatability of measurements and moderate variability among investigators (P > 0.1). For the 20 normal children the mean (sd) AP sacral ratio was 0.74 (0.156); in the 14 with anorectal conditions and a normal sacrum it was 0.87 (0.16) and in the 12 with an abnormal sacrum 0.64 (0.27). There was a difference (P < 0.02) among the three groups (analysis of variance) but there was wide variability in individual sacral ratios within each group, and considerable overlap of values between normal and abnormal sacra. When all sacra were defined as normal or abnormal using Pena's criteria, there was poor agreement using Cohen's kappa (AP and lateral view) with the radiological diagnosis by all four investigators. CONCLUSION: The sacral ratio has good inter- and intra-observer repeatability. The mean value for a normal AP ratio concurred with that described previously by Pena but the variability of values among similar patients was large, suggesting this single value is of limited value in discriminating a normal from an abnormal sacrum.

Analysis of Variance↗
PubMed2003

Broiler survivors of intravenous micro-particle injections: evaluation of growth, livability, meat quality, and arterial blood gas values during a cyclic heat challenge.

When broilers are exposed to high ambient temperatures, their cardiac output can increase by 20 to 50%. Previously, we developed an intravenous micro-particle injection technique to select broilers having a cardiopulmonary capacity capable of accommodating increases in cardiac output associated with fast growth and cool temperatures. In the present study, male broilers were injected at 18 to 20 d of age with cellulose micro-particles sufficient to trigger >50% mortality by 35 d of age. The survivors of micro-particle injections (cellulose survivors) and saline-injected flock mates (control group) were exposed to a moderate cyclic heat challenge (peak temperature of 35 to 37 degrees C) beginning on d 36 and continuing through d 57. We tested the hypothesis that if the cellulose survivors represent the population cohort having the most robust cardiopulmonary capacity, then during a subsequent heat challenge these survivorspotentially may perform better than their unselected flock mates. Based on data combined from two independent experiments, the cellulose survivors exhibited improved livability and body weight gain when compared with their unselected flock mates during the cyclic heat challenge. Meat quality characteristics did not differ between the groups. In a third experiment, cellulose survivors and saline-injected male broilers were reared at thermoneutral temperatures or were exposed to a cyclic heat challenge beginning on d 36. Arterial blood samples were collected from unanesthetized birds at 47 to 49 d of age and were analyzed for pH, partial pressure of CO2, bicarbonate, partial pressure of O2, and saturation of hemoglobin with O2. The blood gas values for the cellulose survivors and saline-injected broilers did not differ within a temperature regimen, regardless of whether the broilers were chronically acclimated to heat or were exposed to an acute heat challenge at the end of the experiment. The cellulose survivors did not differ in susceptibility to panting-induced respiratory alkalosis or hypoxemia when compared with their saline-injected flock mates. Overall, these observations indicate that selection for a robust cardiopulmonary capacity can confer advantages in growth and livability without affecting meat quality when broilers are exposed to a moderate heat challenge.

Animals↗
PubMed2002

Role of chest computed tomography at diagnosis in the management of Wilms' tumor: a study by the United Kingdom Children's Cancer Study Group.

PURPOSE: This study sought to determine whether the identification of minimal pulmonary metastatic disease by chest computed tomography (CT) performed at diagnosis in patients with Wilms' tumor and normal chest x-rays (CXR) could predict a subgroup of children at increased risk of pulmonary relapse. PATIENTS AND METHODS: A retrospective analysis was carried out of the records of 449 children entered onto the United Kingdom Childrens' Cancer Study Group Second Wilms' Tumor Study between July 1986 and September 1991. The imaging protocol did not stipulate chest CT at diagnosis, but 141 children who had normal frontal and lateral CXRs and a chest CT scan performed at diagnosis were eligible for analysis. After surgery, children with stage I Wilms' tumor received single-agent chemotherapy (vincristine), whereas children with stages II, III, and bilateral Wilms' tumor received combination chemotherapy. Most children with stage III tumors were also treated with abdominal radiotherapy (20 Gy). RESULTS: In 31 patients (22%), pulmonary nodules were visible on chest CT; eight experienced relapse, four (15%) in the lungs. When only stage I patients were analyzed, there was a significant difference between the pulmonary relapse rate of 43% (three of seven) in the CT-positive group and 10% (five of 48) in the CT-negative group (P =.02). Four of eight patients with stage I disease with pulmonary relapse died. CONCLUSION: CT seemed to identify a subgroup of stage I patients who were at increased risk of pulmonary relapse. These children had received only single-agent chemotherapy. A prospective randomized trial is needed to clarify whether these children would benefit from combination chemotherapy.

Antineoplastic Agents, Phytogenic↗
PubMed2002

The characterization and incidence of pale, soft, and exudative broiler meat in a commercial processing plant.

Pale, soft, exudative (PSE) turkey meat is a growing problem for the industry of further processed poultry meat. The low pH condition due to rapid glycolysis while the body temperature is still high leads to protein denaturation, causing pale color and reduced water-holding capacity. This condition impacts product yield and quality. These studies were designed to estimate the incidence of PSE broiler meat in a commercial plant and to use response surface methodology to characterize the relationship between pH and lightness (at deboning and at 24 h postmortem), expressible moisture, drip loss, and cook loss. Pale fillets had significantly lower pH, greater L* values at 3 and 24 h postmortem, and higher expressible moisture, drip loss, and cook loss. The lower water-holding capacity of the pale fillets was characteristic of PSE meat. Additionally, L* values were measured on 3,554 boneless broiler breast fillets in a commercial processing line. By using the L* value range (>54) from the pale group of fillets as an indication of paleness, approximately 47% of the 3,554 fillets were pale and could potentially exhibit poor water-holding capacity. These results may not represent the entire industry but indicate that PSE chicken can represent a substantial proportion of commercially processed broiler meat.

Animals↗
PubMed2002

Spinal ultrasound in infants.

This paper discusses the indications for spinal ultrasound, including its advantages and disadvantages compared with spinal MRI. The features and ultrasound findings both in normal infants and in those with spinal dysraphism are reviewed.

Humans↗
PubMed2001

Radiology of neuroblastoma in children.

The radiology of neuroblastoma reflects the diversity of the manifestations of this condition. The current radiological practice for imaging is outlined and illustrated with emphasis on cross-sectional and radionuclide imaging.

Child↗
PubMed2001

Spinal ultrasound in cloacal exstrophy.

AIM: To assess the diagnostic value of spinal ultrasound in cloacal exstrophy, a caudal malformation which is associated with spinal dysraphism, and to assess the prevalence of spinal dysraphism in cloacal exstrophy. MATERIALS AND METHODS: Ten infants under 1 year old with cloacal exstrophy underwent spinal ultrasound at presentation. Three patients also had a magnetic resonance imaging (MRI) examination. Ultrasound and MRI images were reviewed and correlated. RESULTS: Nine of 10 patients had no external signs of spinal dysraphism. One patient had a clinically apparent myelomeningocele. Five of 10 patients (50%) had spinal dysraphism on ultrasound: there were two patients with a low cord, two with tethered cords and a lipoma, and one patient with tethering and a myelomeningocele. Thus, in four of these five patients spinal dysraphism was occult. In a small number of patients (n = 3) MRI was also performed-in these cases the MRI and ultrasound appearances correlated, however MRI was not performed in those patients in whom spinal ultrasound was normal. CONCLUSION: In three cases where spinal ultrasound detected occult dysraphism and MRI was performed, spinal ultrasound and MRI correlated. Advantages of spinal ultrasound include ease of examination, production of high quality multi-planar images and the facility for portable imaging at the bedside. Spinal ultrasound should be the first investigation in all babies with cloacal exstrophy to diagnose occult and non-occult spinal dysraphism.

Cloaca↗
PubMed2000

The development of pale, exudative meat in two genetic lines of turkeys subjected to heat stress and its prediction by halothane screening.

Previous research has indicated that seasonal-type heat stress (HS) can contribute to the development of pale, soft, exudative (PSE) meat in fast-growing turkeys and that halothane exposure may identify stress-susceptible animals. This study evaluated the ability of halothane screening to identify stress-susceptible birds prone to developing pale, exudative meat when reared to market age. Two lines of turkeys (n = 292), one selected for rapid overall growth (BODY) and the other for large breast muscle yield (BREAST), were exposed to 3% halothane for 5 min at 2 to 4 wk of age and were raised together until 16 wk of age. Approximately 10% of both BODY and BREAST birds were sensitive to halothane. Between 16 and 20 wk, all of the halothane sensitive (HAL+) and half of the halothane nonresponders (HAL-) were exposed to an HS environment of 30 to 36 C (night/day), whereas the other half of the HAL- birds were kept at an ambient temperature of 13 to 21 C (night/day). All birds were slaughtered at 20 wk of age, and samples were collected for pH, L* value, drip loss, cooking loss, and shear value. The BREAST strain had 5% greater breast percentage than the BODY strain, and there were no differences in ready-to-cook yields between any treatments. The HAL+ HS birds had significantly lower muscle pH (0 h) and significantly higher L* values at 2 h postmortem compared with HAL- HS birds in the BREAST strain; however, there was no difference in L* value at 24 h postmortem. The HAL- HS birds had significantly lower muscle pH (0 h and 2 h) and significantly higher L* values at 2 h postmortem compared with HAL- controls in the BODY strain. The HAL- HS BREAST birds had significantly higher drip loss than HAL- controls. No differences in shear value were found among any treatments. The incidence of PSE (2-h L* values >52) was significantly higher in HAL+ HS birds (34.7%) compared with HAL- HS birds (13.4%). These results suggest that halothane sensitivity early in life is associated with HS susceptibility and the development of pale meat when birds are slaughtered at market age. These results also suggest that halothane screening may be better at predicting the development of PSE meat during HS in the strain selected for large breast yield rather than rapid overall growth.

Animals↗
PubMed2000

The characterization and incidence of pale, soft, exudative turkey meat in a commercial plant.

Pale, soft, exudative (PSE) turkey meat is a growing problem for industry and has been associated with rapid postmortem pH decline and loss of protein functionality, similar to PSE pork. This study was designed to estimate the incidence of PSE meat in a commercial plant and use response surface methodology to characterize the relationship between pH, lightness (L* value), and water-holding capacity (WHC). One hundred thirty-four turkey breast fillets were selected from the processing line so that 67 had normal color (lightness), and the other 67 were more pale than normal. Fillets were analyzed at time of deboning (1.5 h postmortem) and at 24 h postmortem for color (L* value), pH, drip loss, expressible moisture, and temperature. Additionally, L* values were measured on 2,995 turkey breasts from the processing line to determine the commercial incidence of PSE meat based on color. The pale fillets had significantly lower pH, greater L* value, and less WHC but equal temperature when compared with the fillets with normal color. The L* value and pH were correlated with WHC as measured by expressible moisture, but L* value seems to have more predictive value. By using the L* value range (>53) from the pale-selected fillets as an indication of paleness, approximately 40% of the 2,995 fillets would exhibit poor WHC. These results suggest that PSE meat can represent a significant portion of commercially processed turkey breast meat and that the L* value measurement could be used to sort turkey meat so that PSE type meat could be used in specialized formulations.

Animals↗
PubMed2000

The use of halothane gas to identify turkeys prone to developing pale, exudative meat when transported before slaughter.

Halothane screening has been used in the swine industry to identify animals susceptible to stress and prone to developing pale, soft, exudative (PSE) meat. This study evaluated the ability of halothane to identify stress-susceptible turkeys prone to developing PSE meat when reared to market age and transported before slaughter. Male Nicholas turkeys (n = 1,286) were exposed to 3% halothane for 5 min at 4 wk of age in two trials. Birds were classified as halothane sensitive (HAL+) or halothane nonresponder (HAL-), in which HAL+ birds showed signs of muscle rigidity in the legs upon removal from halothane gas, and HAL- birds showed no stiffness response. Approximately 3.5% (45) of the turkeys were HAL+. All HAL+ birds and an equal number of HAL- birds were grown until 20 wk of age. Immediately prior to slaughter, all birds were transported in coops on a flatbed trailer for 2 h and then immediately slaughtered upon arrival at the processing plant. Breast muscle pH (0, 1.5, and 24 h postmortem) and L* value (1.5 h and 24 h postmortem) were measured on the fillets. Drip loss and cook loss were also determined on marinated and nonmarinated breast fillets from each carcass. There were no significant mean differences in any parameter measured between the HAL+ and HAL- turkeys. However, the HAL+ turkeys had a greater percentage of fillets with L* values >51 compared with the HAL- turkeys. These results suggest that either halothane response is only a limited predictor of PSE meat in turkeys or that transportation is not an appropriate stressor to induce the PSE condition.

Anesthetics, Inhalation↗
PubMed2000

The influence of transportation on turkey meat quality.

Previous research has indicated that antemortem stress factors can influence the development of pale, soft, and exudative (PSE) meat in swine as well as in turkeys. Such antemortem factors can include environmental temperatures, relative humidity, preslaughter handling practices, and transportation. However, the effect of transportation on meat quality of turkeys has not been extensively studied. Eighty Nicholas male turkeys (21 wk of age) were divided into two groups and were either transported in coops on a flatbed trailer for 3 h immediately prior to processing or processed without transportation. Breast muscle samples were collected for pH (0, 2, 24 h), L* value (2, 24 h), drip loss, and cook loss. Additionally, breast fillets were marinated and cooked to determine marination uptake, retention, and cook loss. The breast muscles from transported turkeys had significantly higher muscle pH at 0, 2, and 24 h; significantly lower L* values at 2 and 24 h; significantly higher marination retention (i.e., lower drip loss after marination); and significantly lower cook loss in the marinated fillets compared with fillets of the nontransported turkeys. There were no significant differences in drip loss and cook loss of the nonmarinated fillets or the marination uptake percentage between the transported and nontransported turkeys. These results suggest that transporting turkeys immediately before processing does not induce PSE meat and may actually improve water-holding properties.

Animals↗
PubMed2000

Efficacy of chest CT in a pediatric ICU: a prospective study.

STUDY OBJECTIVES: (1) To determine whether chest CT provides additional information compared with chest radiography regarding the nature of intrathoracic disease in critically ill children, (2) to determine whether such information alters clinical management, (3) to assess the role of a low-dose high-resolution CT (HRCT) protocol in pediatric ICU (PICU) patients. DESIGN: Prospective study. SETTING: Specialized PICU in a teaching hospital serving London and the south of England. PATIENTS: Twenty children (age range, 3 weeks to 12 years; median, 11 months) underwent chest CT during a 33-month period. Inclusion criteria were (1) inconclusive diagnosis from chest radiograph (CXR) or (2) CXR appearances inconsistent with high oxygenation or ventilatory requirements (PaO(2) to fraction of inspired oxygen ratio < 30 or mean airway pressure > 15 cm H(2)O). INTERVENTIONS: Low-dose HRCT scans (50 mA, 2-mm slice thickness at intervals of 10 or 15 mm) were performed on 12 patients, and helical CT (50 to 250 mA; pitch, 1 to 1.5) performed on 8 patients. MEASUREMENTS AND RESULTS: CT provided additional information regarding the nature of intrathoracic disease in 17 of 20 patients (85%) and resulted in changes to subsequent clinical management in 12 of 20 patients (60%). CONCLUSIONS: Chest CT can add to the accuracy of intrathoracic diagnosis provided by the CXR and may directly influence the acute management of critically ill children. The CT protocol should be tailored to the clinical and radiologic question posed for each individual patient. Noncontiguous HRCT can often provide accurate assessment of pulmonary parenchymal and pleural disease at a reduced radiation dose compared with helical CT.

Child↗
PubMed1999

Distribution and pathophysiology of acute lobar collapse in the pediatric intensive care unit.

OBJECTIVE: The high incidence of lower lobe collapse in adult intensive care patients is well described. We aimed to document the incidence and distribution of acute lobar collapse in the pediatric intensive care setting. The influence of anatomical and pathophysiological differences between the adult and pediatric respiratory tract will be considered. DESIGN: Retrospective review of chest radiograph series. SETTING: Tertiary referral center for pediatric intensive care and the Department of Diagnostic Radiology in a large teaching hospital in England. PATIENTS: Cohort of 160 patients receiving intensive care during a 2-yr period (age range, 6 days-18 yrs; median, 23 months). INTERVENTIONS: None MEASUREMENTS AND MAIN RESULTS: Twenty-four of 160 children (15%) developed acute lobar collapse during their intensive care unit admission. Isolated right upper lobe collapse occurred in 14 patients, right upper lobe in association with one or more other lobes in five patients, and lobar collapse other than the right upper lobe in five patients. The development of lobar collapse and, in particular, right upper lobe collapse was associated with a lower median age (no collapse, 26 months; lobar collapse, 8 months; right upper lobe collapse, 4 months). Lobar collapse was significantly associated with the requirement for mechanical ventilation during admission (chi-square, 12.18; p = .005). It was observed in association with both high and low endotracheal tube positions. CONCLUSION: The predominance of upper lobe and, in particular, right upper lobe collapse observed in pediatric intensive care patients contrasts with the high incidence of lower lobe collapse in their adult counterparts. Multiple interrelated factors are likely to be contributory and include the following: a) anatomical and physiological differences between adults and children; b) the pathophysiology of childhood respiratory disease; c) more critical positioning of endotracheal tubes in younger patients and their movement with patient positioning.

Adolescent↗
PubMed1998

Meat quality of broiler breast meat following post-mortem electrical stimulation at the neck.

This experiment was conducted to evaluate the effects of electrical stimulation (ES) on breast fillets harvested at 1 h post-mortem and individually quick frozen (IQF) or aged on ice (ICE). Twelve birds were electrically stimulated (450 V, 750 mA, 2 s on/1 s off for 15 s) at the neck in a saline bath. Twenty-four unstimulated birds were used as controls. Breast fillets were harvested at 1 h post-mortem from ES and control carcasses or at 4 h post-mortem from control carcasses and were either IQF or ICE until 24 h post-mortem. Fillets were then analyzed for shear value, pH, R value, and color. Electrical stimulation significantly reduced shear values compared to the 1 h controls for both IQF and ICE treatments. The ICE fillets deboned at 1 h from ES-treated carcasses had shear values similar to those of ICE fillets deboned from the 4 h controls. Electrical stimulation increased the percentage of shear values at or below 8 kg/g for the fillets from ES-treated carcasses compared to the 1 h controls. Electrical stimulation accelerated the normal post-mortem decline in pH and increase in R value. There was no significant difference in L* or a* values between the fillets held for 1 or 24 h. The results suggest that by electrically stimulating carcasses at the neck using a saline bath, the aging period could be eliminated by removing fillets immediately after chilling at 1 h, decreasing the costs associated with aging whole carcasses or front halves.

Animals↗
PubMed1997

Muscle metabolism and meat quality of Pectoralis from turkeys treated with postmortem electrical stimulation.

This experiment was conducted to evaluate the effects of electrical stimulation (ES) on muscle metabolism and breast meat quality in turkeys. Thirty-six turkey hens were either ES at the neck in a saline bath (570 V, 450 mA, AC, 60 Hz, 2 s on 1 s off for 10 pulses) or used as unstimulated controls. One breast fillet from all carcasses was harvested at 2 h postmortem. The opposite fillet was harvested from the ES carcasses at 8 h postmortem and from the unstimulated controls at either 8 or 24 h postmortem. All fillets were sampled at time of deboning for expressible moisture, pH, R-value, gravimetric fragmentation index (GFI), and sarcomere length. The remainder of the fillet and the samples for GFI and sarcomere length were aged on ice until 24 h postmortem. After aging, fillets were analyzed for cook loss and shear value. Color was measured at time of deboning and at 24 h postmortem. Electrical stimulation accelerated rigor mortis development as indicated by significantly lower pH values and higher R-values at 2 h postmortem when compared to control fillets. The pH and R-values of the 2-h ES treatment were not significantly different from the 8-h ES, 8-h controls, or the 24-h controls. Fillets from carcasses that were ES and deboned at 2 h had significantly longer sarcomeres than the 2-h controls; however, there were no significant differences between the 2-h ES and the 8-h ES treatments, 8-h controls, or the 24-h controls. Although ES accelerated muscle metabolism at 2 h postmortem, it had no effect on shear value, expressible moisture, cook loss, GFI, L*, or a* color values. These results suggest that this postmortem ES system would not benefit turkey processors.

Animals↗
PubMed1996

Pictorial review: the radiological spectrum of vertically-acquired HIV infection.

Anonymous antenatal and newborn screening demonstrates a positive HIV seroprevalence of one in 400 in areas of inner city London. European Collaborative Study data show a vertical transmission rate of 15% and suggests that 23% of infected children will develop clinical manifestations of AIDS before reaching 1 year of age [1], meaning that recognition of the radiological findings in vertically-acquired HIV is important. 75 serial cases of vertically-acquired HIV (age range 6 weeks to 12 years, mean age 35 months) presenting to a national referral centre over 48 months were reviewed; the radiographic findings we describe constitute a core of typical abnormalities together with a selection of the rarer manifestations of vertically-acquired HIV.

AIDS-Related Complex↗
PubMed1994

Plain chest radiographic changes of the absent pulmonary valve syndrome.

The plain chest radiographs of 40 patients with the absent pulmonary valve syndrome in association with tetralogy of Fallot have been reviewed. The conventional frontal projection showed characteristic changes of massively dilated central pulmonary arteries with normal peripheral markings in all patients (100%). Lobar hyperinflation was present in a significant proportion of the infant group (38%) which in a smaller group can be a complication requiring surgery in addition to that for the cardiac malformation.

Cardiomegaly↗