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Biomedical subjects

J P McCann

Publications and source records attributed to J P McCann.

At least 19 recordsLinked to original sources

Unrecognised spinal cord compression as a cause of morbidity.

Predicting outcomes is important in planning patient management and rehabilitation. Two cases, one with illustrative radiology, are described. Each presented with potentially preventable morbidity, secondary to unrecognised compression of the spinal cord. Detailed history and examination may have revealed the underlying problem: a condition with potential associated long-term morbidity.

Adult↗

An audit of the provision of environmental control systems in Northern Ireland, 1992-1997.

OBJECTIVE: To evaluate the provision of environmental control systems (ECS) in Northern Ireland with regard to assessment and prescription, installation and review and propose guidelines for future service delivery. DESIGN: Structured interview, physical examination, Barthel ADL Index, demonstration and assessment of suitability of ECS for patient. SUBJECTS: Prescriptions for ECS from April 1992 to 1997 were identified from centrally held records. Current users were assessed in their own homes. RESULTS: Forty-six out of 49 current users identified were assessed. All were severely disabled (Barthel 0-9); 24% were living alone; 7 (15%) were not utilizing the system; 96% were satisfied with their initial assessment. Prior to prescription 52% had information about ECS and 20% had a practical demonstration; 78% felt that this would have been useful; 52% of users were not under routine clinical review; 41% of ECS had been altered since installation. Repairs had taken longer than 7 days in 11% of cases. In 45 cases the ECS was essential and in 43 it was appropriate to the users' needs and abilities. CONCLUSIONS: ECS are a valuable tool for severely disabled persons and are appropriately prescribed in Northern Ireland. A multidisciplinary team should perform assessment and prescription. All patients should have a practical trial of the equipment to assist in prescriptions. Regular review by the team should be performed to identify changes in need and alter systems appropriately. Users who live alone should represent a priority for repairs.

Activities of Daily Living↗

Subcellular distribution and glycosylation pattern of androgen receptor from sheep omental adipose tissue.

Sex steroids are known to have an influence on the distribution, metabolism and accretion of adipose tissue. These steroids carry out their function via specific receptors. We have previously reported the presence of oestrogen and progesterone receptors in sheep adipose tissues. In this study, we have tested the subcellular distribution of androgen receptor (AR) in sheep omental adipose tissue. Subcellular fractions - microsomes, plasma membrane and nuclei-cell debris - were isolated by differential and sucrose gradient centrifugation and confirmed by electron microscopy. The AR was determined in each fraction by Western blot analyses. As anticipated, the receptor was found in the cytosolic fraction, but a high concentration was also present in the microsomal fraction, a lesser amount in the plasma membrane fraction, and only a small amount was left in the nuclei-cell debris fraction. Two minor immunostaining bands with approximate molecular weights of 250 and 140 kDa and a major band at 110 kDa were detected in the cytosolic fraction, but only the 110 kDa band was detected in the membrane fractions. A 104 kDa band was observed on occasion and believed to be a degradation product. The cytosolic isoforms were tested for sensitivity to glycosidases. This treatment resulted in a decrease in the amount of the 250 and 140 kDa bands. To substantiate that the 250 and 140 kDa isoforms were glycoproteins, the cytosolic fraction was chromatographed on Concanavalin A-Sepharose. The 110 kDa band was eluted in the 0.4 M KCl salt wash while the 250 and 140 kDa bands were eluted with alpha-methylmannoside. Treatment of the glycoprotein (alpha-methylmannoside) peak with glycosidases converted the 250 and 140 kDa bands to the 110 kDa band. These data confirm the presence of AR in subcellular fractions of adipose tissue and suggest that it exists in various glycosylated isoforms.

Adipose Tissue↗

Hemithyroidectomy in a horse with confirmed hyperthyroidism.

A 23-year-old Quarter Horse gelding was admitted to the hospital because of cachexia and hyperactive behavior of 1 year's duration. At admission the horse was severely emaciated, tachycardic with a grade V/VI diastolic murmur, pyrexic, polydipsic, enophthalmic, and alopecic. The right lobe of the thyroid gland was noticeably larger than typical. The horse was also hyperexcitable and had a ravenous appetite. A presumptive diagnosis of hyperthyroidism was made on the basis of clinical signs and high plasma thyroid hormone concentrations. Confirmation of the diagnosis was made on the basis of results of a triiodothyronine-suppression test. Following endocrine testing, the affected portion of the thyroid gland was removed and identified histologically as an adenoma. Return or plasma thyroid hormone concentrations to reference range values and resolution of the clinical signs of disease following hemithyroidectomy provided further conformation of the diagnosis. On the basis of finding in this horse, it appears that horses with hyperthyroidism may be successfully treated by hemithyroidectomy.

Animals↗

Issues of medical management in adults with spina bifida.

The objective of this study was to establish the range of medical issues among those attending a clinic for adults with spina bifida (SB) and hydrocephalus (CASBAH). Owing to improvements in medical care in the past 3-4 decades, an increasing number of SB patients go on to prosper in adult life. Since 1990 there has been a CASBAH service in Belfast serving Northern Ireland on a regional basis. There are now 237 patients with SB remaining on the live register at CASBAH. All records were reviewed with regard to site of lesion, ambulatory ability, shunt placement and regularity of attendance. The records of 193 were also reviewed with reference to musculoskeletal problems, bladder function, bowel function, renal impairment and hypertension, skin breakdown, epilepsy and the incidence of clinically significant Chiari/hydrosyringomyelia. Of the patients on the register, 36% are wheelchair dependent, 8% have some ambulatory capacity but are largely wheelchair dependent, 22% are ambulatory with aid and 34% are independently ambulatory. Bladder function is normal in 8%, whilst 32% describe normal bowel function. Renal impairment is present in 48% of patients, and 15% are on anti-hypertensive therapy. Epilepsy is an active issue in 9%, and intraventricular shunts are in situ in 37% of patients. Scoliosis is present in 50% and 70% have joint deformities or contractures. Five patients have become symptomatic from the Chiari/hydrosyringomyelia complex. These data reflect the considerable range of disability in adult SB patients, the challenges presented in long-term management and the need for organised follow-up.

Activities of Daily Living↗

Prevalence of the Chiari/hydrosyringomyelia complex in adults with spina bifida: preliminary results.

AIM: To establish the prevalence of Chiari malformations and hydrocephalus (HS) in adults with spina bifida (SB). INTRODUCTION: Adults with SB have recently been shown to be at risk from significant deterioration arising from the C/HS complex. Little is known about the prevalence of these malformations in adulthood, their natural history, risk factors for deterioration and optimum management. MATERIALS AND METHODS: Patients are recruited from a clinic for adults with SB and hydrocephalus, routinely questioned about recent changes in neurological symptoms and a full neurological examination performed. Functional assessments include: Barthel Index; Nottingham EADL; Nine Hole Peg Test; 10 metre timed walk test. Sagittal T1 and TSE (turbo spin-echo) magnetic resonance images (MRI) of the cranio-cervical junction and spinal cord are obtained using a 1.0-T MRI system with a phased-array surface coil. Scans are reported blindly. RESULTS: 76 patients have been assessed, 40 female, 36 male, mean age 27.5 years. Of these, 48 (63.2%) have symptoms +/- signs compatible with C/HS, but only 18 (23.7%) have reported new, potentially relevant, neurological symptoms over the previous 12 months. Of 25 patients undergoing MRI so far, 19 (76%) have had Chiari malformations and 12 (48%) have had HS. None of those with a negative scan have had signs/symptoms suggestive of the C/HS complex but a negative clinical evaluation has been unable to exclude such pathology. CONCLUSIONS: These early results suggest that the prevalence of the C/HS complex is high in adults with SB and cannot be predicted by neurological examination alone. Given past experience, the need for continued neurological follow up in a large proportion of the SB population throughout adulthood is likely to be essential.

Activities of Daily Living↗

Why do adults with spina bifida and hydrocephalus die? A clinic-based study.

AIM: To establish the death rate and factors contributing to death among attenders at a clinic for adults with spina bifida and hydrocephalus (CASBAH). INTRODUCTION: Due to improvements in medical care in the past 40 years, increasing numbers of spina bifida patients go on to prosper in adult life. Despite this, levels of morbidity are high and services for such patients are uneven and unpredictable. MATERIALS AND METHODS: Since 1990 there has been a CASBAH service in Belfast operating on a regional basis. Led by a consultant in rehabilitation medicine, it provides a multidisciplinary approach to patient care. Between 1990 and 1999 there have been 280 referrals to the clinic. Charts were reviewed regarding current health status and mode of death where relevant. RESULTS: There have been 18 deaths during the term of the clinic (6.4%). There were four deaths due to renal failure and two due to cardiac failure. Two deaths occurred following surgery for a Chiari/hydrosyringomyelia complex and one patient died due to shunt malfunction. Three deaths were presumed related to infection. Two deaths were attributable to malignancy (carcinoma of a renal conduit and transitional cell carcinoma of the kidney) and other terminal events in one patient each were: basilar artery aneurysm rupture, post-partum pulmonary embolism, peptic ulcer disease, myocardial infarction and status epilepticus. CONCLUSIONS: Although certain deaths were unpredictable during the period of review and not directly attributable to spina bifida, the majority reflect many of the related secondary health issues of the condition and indicate the need for organised, medically co-ordinated follow-up of adult patients.

Adult↗

The Chiari/hydrosyringomyelia complex presenting in adults with myelomeningocoele: an indication for early intervention.

OBJECTIVE: To determine how adults with myelomeningocoele who develop the Chiari/hydrosyringomyelia complex present, and to determine if surgical intervention influences outcome in these patients. METHODS: A chart review of the 220 patients who attend a clinic for adults with spina bifida and hydrocephalus (CASBAH), and follow-up of the five cases with myelomeningocoele who had surgical intervention for associated symptomatic Chiari/hydrosyringomyelia complex. RESULTS: Bilateral upper limb weakness and wasting were the commonest presenting symptoms (four patients). Sensory disturbance (three patients) was also common, dysphagia (one) and ataxia (one) occurring less often. The median time to surgical intervention was 36 months. Two patients had a shunting procedure performed in isolation, two foramen magnum decompression in addition to a shunting procedure and one a foramen magnum decompression. Surgical intervention did not completely reverse problems attributed to the Chiari/hydrosyringomyelia complex in any of the cases. One patient died post-operatively. Of the four who survived one had some improvement in function post-operatively, two remained static and one had further mild deterioration. CONCLUSION: All adults with myelomeningocoele should be questioned about changes in upper limb function for early detection of Chiari/hydrosyringomyelia complex. Our results suggest that early intervention is needed if further deterioration is to be avoided, and to improve the chances of neurological and functional recovery.

Adult↗

The effect of bovine somatotropin treatment on production of lactating angora does with kids.

Fourteen Angora does (35+/-2 kg), each with a single kid and in the first month of lactation, were used to determine ongoing (Period 1) and residual (Period 2) effects of chronic bovine somatotropin (bST) treatment. Specifically, we sought to determine whether chronic bST treatment was capable of improving milk yield, and thus kid growth, and mohair production of nursing does. The experiment consisted of a 2-wk pretreatment period, 5 wk of weekly subcutaneous treatment of slow-release bST (n = 7; Period 1), and a 4-wk posttreatment period (Period 2). The weekly dose of bST was calculated to release 100 microg/(kg BW.d(-1)). To estimate milk production, kids were separated from the does daily for 5 h, and their BW was recorded before and after suckling. The difference in BW was taken as milk production for 5 h. Fiber growth was measured by shearing does at the start of the experiment and at the end of Periods 1 and 2. Dry matter intake and BW of does were not affected by bST (P>.05). Average daily gain of kids that were suckling bST-treated does was higher (P<.05) than for kids of untreated does during Period 1 (184 vs. 139 g/d) but not during Period 2 (140 vs. 136 g/d; P>.10). Treatment with bST did not affect (P>.10) milk composition or clean fleece production in either period. Injection of bST did not affect (P>.10) plasma concentrations of glucose (mean = 49.5 mg/dL), urea N (mean = 19 mg/dL), total protein (mean = 72.5 g/d), or NEFA (mean = 122 microEq/L). During the period of bST treatment, plasma concentrations of somatotropin and IGF-I were increased (P<.05), concentrations of thyroxine and cortisol were decreased (P<.10), and plasma insulin levels were unchanged (P>.10) by bST. In conclusion, treatment of Angora dams with bST did not change DMI or mohair growth, but it improved growth of their kids.

Animals↗

Effects of bovine somatotropin and ruminally undegraded protein on feed intake, live weight gain, and mohair production by yearling Angora wethers.

Yearling Angora wethers (n = 24; 24+/-1.0 kg BW) were used in an experiment with a 2 x 2 factorial arrangement of treatments to investigate effects of bovine somatotropin (bST) treatment and dietary level of ruminally undegraded protein on DMI, ADG, and mohair production. Untreated casein (UC) or casein treated with formaldehyde (TC) was included at 7% DM of a diet containing 11% CP and 46% concentrate. A slow-release bST form was administered weekly to deliver 0 (Control) or 100 microg/ (kg BW.d) of bST. Plasma concentrations of bST and IGF-I were increased (P < .05) during the 7-d period following bST injection. Ruminal fluid ammonia N concentration was lower (P < .01) for TC than for UC before feeding (6.6 vs 7.5 mg/dL) and 4 h later (8.2 vs 12.2 mg/dL), and total VFA concentration was lower (P < .01) for TC than for UC. Treatment with bST decreased (P = .08) DMI with UC (1.15 vs .91 kg/d) and increased (P = .08) DMI with TC (.95 vs 1.06 kg/d). Formaldehyde treatment of casein increased ADG (65, 74, 55, and 91 g/d; P = .03) and clean fleece production (P < .01; 14.1, 17.3, 15.0, and 18.4 g/d for UC-Control, TC-Control, UC-bST, and TC-bST, respectively), with no effect of bST during the 8-wk period of treatment or for the 8 wk thereafter (P > .10). In conclusion, with yearling Angora wethers, bST does not seem useful to enhance mohair production and may not alter effects of dietary level of ruminally undegradable protein on mohair production.

Amino Acids↗

Adrenocortical response to ACTH in Angora and Spanish goat wethers.

Angora goats do not cope well with stress compared with goats of other breeds. Our hypothesis that this involves subclinical primary hypoadrenocorticism associated with low cortisol release in response to ACTH stimulation was tested by measuring adrenocortical response (plasma cortisol) in six Spanish (37 +/- 2 kg BW) and six Angora wethers (39 +/- 3 kg BW) under simulated acute and chronic ACTH challenges. In Exp. 1 (acute ACTH challenge), wethers were dosed i.v. with high (2.5 IU/kg BW) or low (.4 IU/kg BW) quantities of ACTH. In Exp. 2 (chronic ACTH challenge), ACTH at the rate of .015 IU/(kg BW x min) or saline (.15 M NaCl) was infused i.v. at 15 mL/h for 6 h. The mean baseline plasma cortisol concentration before ACTH stimulation was similar (P > .05) between Angora and Spanish goats in Exp. 1 (averaged over days) and in Exp. 2. The cortisol concentration response area (ng/ (mL x min) x 10(-3)) above the baseline was similar (P > .05) between Angora and Spanish goats during low (7.6 +/- .5 and 9.0 +/- 1.7, respectively) and high (12.8 +/- 1.0 and 16.0 +/- 1.8, respectively) levels of acute ACTH challenge (Exp. 1) and during chronic ACTH challenge (45.1 +/- 5.9 and 41.8 +/- 7.3, respectively; Exp. 2). In conclusion, these data indicate that, under the conditions of this study, adrenocortical responsiveness to ACTH stimulation is not different between Angora and Spanish goat wethers and, thus, may not contribute to stress susceptibility in Angora goats.

Adrenal Cortex↗

Plasma cholecystokinin-8 in pigs with divergent genetic potential for feed intake and growth.

Plasma cholecystokinin-8 (CCK-8) was studied in pigs with divergent genetic potential for feed intake. Differences in feed intake resulted from selection for either fast (line F) or slow (line S) postweaning gain. The hypothesis was that the relatively lesser feed intake in S versus F may be attributable, in part, to greater circulating concentrations of the putative satiety hormone CCK-8. In Experiment I, barrows from F (n = 23) and S (n = 19) were used to determine changes in CCK-8 associated with ad libitum feed consumption. Blood samples were collected after overnight feed deprivation, then periodically during a 2-hr feeding period. Averaged across sampling times, concentration of CCK-8 tended to be greater (P = 0.07) in S (6.70 pmol/l) than in F (5.06 pmol/l). Concentration of CCK-8 per unit of feed consumed (CCK-8/cumulative feed intake) was greater (P < 0.01) in S than in F during the first 30 min of the feeding period. In Experiment 2, plasma concentrations were determined for nine pairs (F, S) of the same barrows allowed an amount of feed equal to the previous ad libitum intake of the S barrow in the pair. Averaged across times, the difference between CCK-8 concentrations of S (11.65 pmol/l) and F (7.94 pmol/l) barrows was not significant (P = 0.18). A greater concentration of CCK-8 per unit of feed consumed in S than in F supports the hypothesis that satiety effects of CCK-8 may play a role in genetic differences between the lines for feed intake.

Animals↗

GnRH antagonist inhibition of luteinizing hormone secretion and ovulation in the pig.

A GnRH antagonist, Ac-D-p-Cl-Phe1,2, D-Trp3, D-Arg6, D-Ala10 GnRHb (Organon), was utilized to determine the effective dosage and duration to inhibit LH secretion in the pig. In a preliminary trial, barrows received either 10, 50, or 250 micrograms/kg BW of the GnRH antagonist. Secretion of LH was inhibited within 30 min for a duration of 12 h with the 100 micrograms/kg dose but persisted for greater than 48 h with the 250 micrograms/kg treatment. A second study determined effectiveness of the antagonist for inhibiting ovulation in cyclic gilts. At first detection of standing estrus, cyclic gilts were treated with either saline (control), 100, or 200 micrograms/kg BW of the GnRH antagonist (GnRH1). A second group of GnRH antagonist gilts received 200 micrograms/kg BW of the GnRH antagonist approximately 8 h prior to standing estrus (GnRH2). The GnRH1-treatment failed to inhibit or delay ovulation. Ovulation was inhibited and estrous cycles lengthened in GnRH2-treated gilts. These preliminary results suggest that ovulation in the gilt can be inhibited if the GnRH antagonist is administered prior to the LH surge.

Animals↗

Differential effects of GH stimulation on fasting and prandial metabolism and plasma IGFs and IGF-binding proteins in lean and obese sheep.

The effect of body condition per se on plasma IGFs and IGF-binding proteins (IGFBPs) and the whole-body metabolic responses to recombinant DNA-derived bovine GH (rbGH) in both the fed and the fasted state were determined in lean and dietary obese sheep (n = 6/group). Sheep at zero-energy balance and equilibrium body weight were injected s.c. for 12 days with 100 micrograms/kg rbGH immediately before their morning feeding. Before GH treatment, fasting plasma concentrations of insulin (17.0 +/- 1.9 vs 7.5 +/- 0.7 microU/ml), IGF-I (345 +/- 25 vs 248 +/- 10 ng/ml), glucose (52.6 +/- 1.1 vs 48.3 +/- 0.7 mg/dl), and free fatty acid (FFA) (355 +/- 45 vs 229 +/- 24 nmol/ml) were greater (P < 0.05) and those of GH (1.1 +/- 0.2 vs 2.6 +/- 0.3 ng/ml) were lower (P < 0.05) in obese than in lean sheep. Fasting concentrations of IGF-II and glucagon were not affected (P > 0.05) by obesity. GH concentrations were increased equivalently by 6-9 ng/ml in lean and obese sheep during GH treatment. GH caused an immediate and a marked fivefold increase in the fasting insulin level in obese sheep but only minimally affected insulin concentration in lean sheep. The increment in fasting glucose during GH treatment was greater (P < 0.05) in obese (8-12 mg/dl) than in lean (2-5 mg/dl) sheep. Frequent measurements in the first 8 h after feeding and injection of excipient (day 0) or the first (day 1) sixth (day 6) and twelfth (day 12) daily injection of GH showed that prandial metabolism in both groups of sheep was affected minimally by GH. However, GH treatment on day 1 (not days 6 or 12) acutely attenuated the feeding-induced suppression of plasma FFA in both groups of sheep and this effect was significantly greater in obese than in lean sheep. Although obese sheep were hyposomatotropic, the basal and GH-induced increases in plasma IGF-I concentrations were greater (P < 0.05) in obese than in lean sheep. Plasma IGF-II was unaffected by obesity and was not increased by GH stimulation. Western ligand blotting showed that IGFBP-3 accounted for approximately 50-60% of the plasma IGF-I binding capacity in sheep respectively both before and during GH treatment. Basal plasma levels of IGFBP-2 were lower (P < 0.05) and those of IGFBP-3 greater (P < 0.05) in obese compared with lean sheep. GH increased the level of IGFBP-3 equally in lean and obese sheep, but suppressed the expression of IGFBP-2 more (P < 0.05) in lean than in obese sheep. We concluded that the diabetogenic-like actions of GH in sheep were exaggerated markedly by obesity, and were expressed more during the fasted than the fed states. The effects of GH stimulation on the endocrine pancreas may be selective for beta-cells and preferentially enhanced by obesity. GH regulation of IGF-I and the IGFBPs differs in lean and obese sheep.

Analysis of Variance↗

Persistence of the dominant follicle during melengestrol acetate administration and its regression by exogenous estrogen treatment in beef cattle.

Experiments were conducted to test the hypothesis that estrogen treatment will regress a persistent dominant follicle developed during melengestrol acetate (MGA) treatment in the absence of a functional corpus luteum (CL) with normal fertility following development and ovulation of a newly recruited follicle. In Exp. 1, nonlactating beef cows (n = 31) were administered .5 mg.cow-1.d-1 of MGA (d 0) for 14 d with 25 mg of prostaglandin F2 alpha (PGF2 alpha) administered on d 6 and 8 to regress the CL. On d 11 of treatment, approximately half the MGA-treated cows received 5 mg of estradiol valerate (EV) i.m. (MGAEV, n = 14) and the remainder were maintained on MGA (n = 17). Ovaries were checked with ultrasound on d 8, 10, 12, and 14 of MGA treatment and every day until ovulation. A persistent dominant follicle developed in 90% of the MGA-treated cows by d 10 of treatment. Most of the MGA-treated cows ovulated the persistent dominant follicle (n = 13/17), whereas EV treatment regressed the persistent dominant follicle (n = 10/14) with the recruitment of a new follicle that ovulated (n = 8/10). Diameter of the ovulatory follicle was larger (P < .05) for the MGA (19.8 +/- .6 mm) than for the control (15.1 +/- .8 mm) and MGAEV (14.8 +/- .7 mm) cows. In Exp. 2, nonlactating, multiparous beef cows (n = 97) and yearling heifers (n = 38) were equally allotted to either a control, MGA alone, or MGA + estradiol-17 beta (MGAE) group with the same dose of MGA as administered in Exp. 1. The 1st d of MGA feeding was the 1st d of treatment. On d 10 of treatment half the MGA-treated animals were injected i.m. with 5 mg of estradiol-17 beta. In controls, behavioral estrus was detected and animals were artificially inseminated (AI) for 5 d (d 10 to 14 of experiment). All controls not exhibiting estrus by d 15 of experiment were injected with 25 mg of PGF2 alpha. The remaining controls and all MGA cows were observed for behavioral estrus and AI commenced for 7 d following withdrawal of MGA (d 15 to 21 of experiment). More (P < .05) controls (90.3%) than MGA (84.8%) or MGAE (63.6%) cows showed estrus within 7 d after MGA withdrawal. The percentage of animals conceiving to the synchronized estrus did not differ (P > .05) among treatments. The data support our hypothesis that a persistent dominant follicle developed and can be regressed with exogenous estrogen treatment followed by the recruitment and ovulation of a new follicle after MGA withdrawal and fertility of that estrus does not seem to be significantly compromised.

Animals↗