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Biomedical subjects

M Ryan

Publications and source records attributed to M Ryan.

At least 19 recordsLinked to original sources
PubMed2006

Reproductive performance of lactating dairy cows and heifers resynchronized for a second insemination with an intravaginal progesterone-releasing device for 7 or 8d with estradiol benzoate injected at the time of device insertion and 24h after removal.

One aim of this study was to compare the reproductive performance of cows and heifers when resynchronizing returns to estrus for a second insemination by treating with an intravaginal progesterone-releasing device (IVD) for 7 or 8d when estradiol benzoate (EB) was administered at the start of treatment and again 24h after device removal. An additional aim was to document the pattern of onset and characteristics of estrus with each resynchrony treatment. Lactating cows in three herds were synchronized for a first estrus and AI by treatment with an IVD for 8d, starting on Day 0, cloprostenol (0.5 mg im) at device removal and EB at device insertion (2.0 mg im) and 24h after removal (1.0 mg im). Cows were resynchronized for a second estrus starting on Day 23 by reinsertion of IVDs for 7 (IVD-7-EB; n=449) or 8d (IVD-8-EB; n=445) with EB (1.0 mg im) administered at device insertion and 24h after removal. Cows were resynchronized for a third estrus by administration of EB (1.0 mg im) on Day 46, but subsequent treatments (no further treatment, reinsertion of CIDR or administration of EB on Day 55) varied among herds as part of separate studies. Maiden heifers (7-Day, n=68; 8-Day, n=69) were similarly treated as cows in a separate herd, but doses of EB were always 1.0 mg im at device insertion and 0.75 mg im 24h after removal. Heifers were not resynchronized for a third estrus. Cattle were inseminated on detection of estrus at each synchronized estrus. Cumulative pregnancy rates 4 week (66.0%, 276/418 versus 59.1%, 247/418) and 7 week (72.7%, 304/418 versus 67.7%, 283/418) after the start of AI were greater (P<0.05) in the IVD-7-EB cows compared to the IVD-8-EB cows, respectively; this was associated with a 9% increase in conception rates at the second estrus (P=0.051) in the IVD-7-EB cows. Treatment did not significantly affect reproductive performance in heifers. Characteristics of estrus measured with radiotelemetry did not differ significantly between the two treatment groups, but more cows were detected in estrus 36 h after removal of IVDs in the IVD-8-EB cows compared to the IVD-7-EB cows (P<0.05). We concluded that reproductive performance in resynchronized dairy cows but not heifers was greater following resynchronization of estrous cycles after AI with an IVD for 7 compared to 8d when EB was injected at the start of treatment and 24h after device removal.

Administration, Intravaginal↗
PubMed2006

Induced dystrophin exon skipping in human muscle explants.

Antisense oligonucleotide (AO) manipulation of pre-mRNA splicing of the dystrophin gene is showing promise in overcoming Duchenne muscular dystrophy (DMD)-causing mutations. To date, this approach has been limited to studies using animal models or cultured human muscle cells, and evidence that AOs can induce exon skipping in human muscle has yet to be shown. In this study, we used different AO analogues to induce exon skipping in muscle explants derived from normal and DMD human tissue. We propose that inducing exon skipping in human muscle explants is closer to in vivo conditions than cells in monolayer cultures, and may minimize the numbers of participants in Phase I clinical studies to demonstrate proof of principle of exon skipping in human muscle.

Animals↗
PubMed2006

Resting energy expenditure is not increased in mildly hyperglycaemic obese diabetic patients.

Resting energy expenditure (REE) is believed to be increased in type 2 diabetes, an increase that is associated with deteriorating glucose tolerance during its development. Meanwhile, insulin resistance, a state linked to obesity and observed in all type 2 diabetic patients, is associated with reduced REE. Our aim was to compare REE in obese patients with and without diabetes. REE, body composition (total body water, density, percentage fat and fat-free mass: 3-compartment model) and metabolic control were assessed in fifty obese Caucasian patients with diabetes (glycated haemoglobin level 7.6 (SD 1.5) %) and fifty obese patients who were non-diabetic. Despite being more overweight and younger, obese non-diabetic patients had an absolute REE (7.73 (SD 1.44) v. 8.12 (SD 1.37) MJ; P=0.17) and percentage fat-free mass similar to those of obese diabetic patients. Even when adjusted for differences in body composition, REE remained similar in both groups. Furthermore, REE (absolute and adjusted) was unaffected by both glucose level and control (glycated haemoglobin), with fat-free mass being the only determinant of REE. We conclude that REE is not necessarily increased by the presence of diabetes in obese people.

Adult↗
PubMed2006

Medical, surgical, and health outcomes of gastrostomy feeding.

A prospective controlled study with repeated measures before and after surgery examined the medical, surgical, and health outcomes of gastrostomy for children with disabilities at a tertiary paediatric referral centre in the North Thames area, UK. Anthropometric measures included weight, mid-upper-arm and head circumference. Five-day prospective food diaries were completed and data on physical health and surgical outcomes recorded. Seventy-six children participated and underwent gastrostomy (44 males, 32 females; median age 3 y 4 mo, range 4 mo-17 y 5 mo), and 35/76 required an anti-reflux procedure. Categories of disability were: cerebral palsy (32/76), syndrome of chromosomal or other genetic origin (25/76), slowly progressive degenerative disease (11/76), and unconfirmed diagnosis (8/76). Most children had gross motor difficulties (99%) and were non-ambulant (83%). Oromotor problems were identified in 78% of children, 69% aspirated, and 65% were fed nasogastrically before surgery. The mean weight before surgery was -2.84 standard deviation score (SDS; SD 2.21, range -9.8 to 3.4). Two-thirds of children achieved catch-up growth postoperatively: weight-for-age (mean difference 0.51 SDS, 95% CI 0.23-0.79, p=0.001) and mid-upper arm circumference (mean difference 1.12 cm, 95% confidence interval 0.50-1.75, p=0.001). Health gains included a reduction in drooling, secretions, vomiting, and constipation. Major surgical complications were found in 13/74 children. The study provides evidence that catch-up growth and health gains are possible following gastrostomy.

Adolescent↗
PubMed2005

[Emergent pathogens, international surveillance and international health regulations (2005)].

In order to address the vitality of the microbial world, to detect emerging infectious diseases, to determine their potential threat to public health, and to establish effective interventions, the World Health Organization (WHO) has developed and coordinates the Global Outbreak Alert and Response Network (GOARN) which connects several surveillance networks. Some of these networks are specific to epidemic-prone diseases, such as influenza, dengue, yellow fever or meningitis. Others were especially designed to track unusual events--such as the emergence of SARS--that are naturally-occurring, accidental, or deliberately created (biological weapons, bio-terrorism). Lastly, a special effort is being made at the international level to modernize the International Health Regulations, now obsolete, and to support all the countries in the reinforcement of their outbreak alert and response capacity.

Communicable Diseases, Emerging↗
PubMed2005

Persistent organic pollutants and metals in the freshwater biota of the Canadian Subarctic and Arctic: an overview.

Over 1999-2002, an extensive series of contaminant studies was conducted on freshwater biota of Canada's Arctic and Subarctic regions. The majority of inorganic contaminant studies focused on mercury and fish. While mercury concentrations were low in benthic feeding fish such as whitefish, predatory fish such as lake trout, pike, and walleye frequently had mercury levels which exceeded 0.2 mug/g, the consumption guideline for frequent consumers of fish, and 0.5 microg/g, the guideline for the commercial use of fish. Numerous consumption advisories were issued for lakes along the Mackenzie River. Relatively high mercury levels appear to be due to a combination of relatively old fish populations (because of light fishing pressures) and tend to be more prevalent in smaller lakes where warmer summer water temperatures and watershed influences result in greater mercury and methyl mercury inputs. Mercury levels were substantially lower in char than in lake trout, possibly due to a combination of a less fish-rich diet, a colder environment, and smaller MeHg watershed inputs. Less research has been conducted on other metals but some, such as rubidium, show pronounced variations in concentration that may be related to geological influences. Temporal trend monitoring has revealed little evidence of declining mercury levels in fish that can be attributed to declining atmospheric inputs. Because mercury follows complex pathways in the environment, other factors may operate to counteract reductions in atmospheric mercury sources, e.g., climatic variability, changes in the commercial fishery, and interactions between fish species. Most organochlorine (OC) investigations were based on long term trend monitoring and focused on char (Cornwallis Island), burbot (Great Slave Lake, Yukon lakes, Slave River at Fort Smith, Mackenzie River at Fort Good Hope) and lake trout (Yukon lakes, Great Slave Lake). There was strong evidence of declining OC concentrations in char, particularly SigmaHCH and Sigmachlordane, which may reflect a response to declining atmospheric inputs. Endosulfan concentrations increased, as in the atmosphere. There also was evidence of declining OC concentrations in burbot in the Slave and Mackenzie rivers but not in Great Slave Lake and Yukon lakes. OC concentrations decreased in lake trout in Yukon lakes in the 2000s, most probably because of changes in the fish themselves (i.e., reduced lipid content, condition factor) and possibly climatic variability. Similarly, OCs declined in Great Slave Lake trout. New research on PDBEs and perfluorinated compounds determined that these contaminants are widespread in freshwater fish and concentrations may be increasing. Global warming is a major issue of concern for Arctic and Subarctic waters and may have adverse impacts on contaminant levels in fish and other biota. There is a need for contaminant studies in the north to be broadened to investigate climatic effects. In addition, monitoring studies should be broadened to consider factors affecting other aspects of fish biology. Foremost among these is integrating contaminant monitoring studies on lakes such as Lake Laberge and Great Slave Lake with stock assessment studies. Ecosystem based studies should be conducted on Great Slave Lake and Lake Laberge to more effectively understand contaminant trends and should consider inputs (atmospheric, river inflow, resupension), losses (sedimentation, volatilization), and biological pathways.

Animals↗
PubMed2005

A comparison of esomeprazole and lansoprazole for control of intragastric pH in patients with symptoms of gastro-oesophageal reflux disease.

BACKGROUND: Intragastric acid suppression is the most direct measure of the pharmacodynamic efficacy of proton pump inhibitors, which are the most effective drugs for acid-related diseases. AIM: To compare the effectiveness of once and twice daily dosing of lansoprazole and esomeprazole in controlling intragastric acidity (target gastric pH > 4.0) over a 24-hour period. METHODS: In an open-label, two-way crossover study, 45 Helicobacter pylori-negative patients with gastro-oesophageal reflux disease were randomized to receive one of two regimens: 30 mg lansoprazole or esomeprazole 40 mg once daily. Intragastric pH was assessed by 24-hour pH monitoring on day 5 of each regimen. Dosing was increased to twice daily and pH was reassessed on day 10. Following a 14-day washout, patients were crossed over to the other medication and the dosage regimens and pH assessments were repeated. RESULTS: Data were analysed from 35 patients who completed all scheduled assessments and had 24-hour monitoring for each end-point. Mean time pH > 4.0 and mean 24-hour pH were highest for esomeprazole 40 mg twice daily, followed by lansoprazole 30 mg twice daily, esomeprazole 40 mg once daily and lansoprazole 30 mg once daily. Esomeprazole 40 mg twice daily provided superior control of intragastric pH compared with either once or twice daily dosing of lansoprazole and once daily dosing of esomeprazole (P < 0.01). Esomeprazole 40 mg once daily was comparable with lansoprazole 30 mg twice daily and both were superior to lansoprazole 30 mg once daily (P < 0.01). CONCLUSIONS: Response to acid suppression treatment depends on the treatment selected. Esomeprazole 40 mg twice daily provided better control of intragastric pH than all other regimens evaluated. Esomeprazole 40 mg daily, however, was comparable with lansoprazole 30 mg twice daily and superior to lansoprazole 30 mg once daily.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2005

Intron 1 of the interferon gamma gene: Its role in nematode resistance in Suffolk and Texel sheep breeds.

Genetic variation at intron 1 of the interferon gamma gene has recently been associated with variation in faecal egg count in Romney, Merino and Soay breeds of sheep. The Texel breed is more resistant to gastrointestinal nematode infection than the Suffolk breed, based on faecal egg count. Hence, the objective of this experiment was to characterise the polymorphisms of intron 1 of the interferon gammagene in Suffolk and Texel sheep, and to determine if the characterised haplotype variants were associated with faecal egg count variation in these breeds. Intron 1 haplotypes and faecal egg measurements were determined for Suffolks (n=113) and Texels (n=135). Four haplotypes were identified in Suffolks (A, B, C and D), two haplotypes as previously described, and two previously unknown haplotypes. However, there was no association between interferon gamma intron 1 haplotype and faecal egg count in Suffolks. In contrast, two previously identified haplotypes (A and B) were present in the Texel breed, and the B haplotype was associated with resistance to nematode infection (P=0.02). These results suggest that intron 1 of the interferon gamma gene has an important role in resistance to nematode infection in the Texel breed.

Animals↗
PubMed2005

Major histocompatibility complex DRB1 gene: its role in nematode resistance in Suffolk and Texel sheep breeds.

A potential control strategy for nematode infection in sheep is the implementation of a breeding programme to select for genes associated with resistance. The Texel breed is more resistant to gastrointestinal nematode infection than the Suffolk breed, based on faecal egg count, and this difference should enable the identification of some of the genes responsible for resistance. The objective of this study was to determine if variation at the ovine MHC-DRB1 locus was associated with variation in faecal egg count in Suffolk and Texel sheep. Ovar-DRB1 alleles and faecal egg count were determined for Texel (n = 105) and Suffolk (n = 71) lambs. Eight Ovar-DRB1 alleles, including 1 previously unknown allele, were identified in the Texel breed by sequence-base-typing. Seven Ovar-DRB1 alleles were identified in the Suffolk breed. Two Ovar-DRB1 alleles were common to both breeds, but were among the least frequent in the Suffolk population. In the Suffolk breed 1 Ovar-DRB1 allele was associated with a decrease in faecal egg count and 2 alleles with an increase in faecal egg count. This locus accounted for 14% of the natural variation in faecal egg count in Suffolks. There was no evidence for an association between Ovar-DRB1 alleles and faecal egg count in the Texel breed and the Ovar-DRB1 locus accounted for only 3% of the phenotypic variation in faecal egg count. These results suggest that the Ovar-DRB1 gene plays an important role in resistance to nematode infection in the Suffolk breed. The difference in faecal egg counts between these breeds may be attributable in part to the different allele profile at the Ovar-DRB1 locus.

Alleles↗
PubMed2005

'Glucose control-related' and 'non-glucose control-related' effects of insulin on weight gain in newly insulin-treated type 2 diabetic patients.

Insulin use is common in type 2 diabetes and is frequently accompanied by weight gain, the composition of which is poorly understood. The present study evaluates insulin-induced body composition changes. Body weight and composition of thirty-two type 2 diabetic patients undergoing their first 12 months of insulin therapy were compared with those observed in thirty-two type 2 diabetic patients previously treated on insulin (minimum 1 year). Body composition was determined by simultaneous body water spaces (bioelectrical impedance analysis) and body density measurements. After 6 months, glycosylated Hb (HbA1c) significantly improved in the newly treated group (P<0.0001), but remained stable in those treated previously. HbA1c did not differ between 6 and 12 months in the two groups. Body weight significantly (P=0.04) changed over 12 months in those newly treated only (+2.8 kg), essentially comprising fat-free mass (P=0.044). Fat mass remained unchanged (P=0.85) as did total body water, while extracellular: total body water ratio tended to increase in those newly treated (P=0.059). Weight changes correlated with HbA1c changes (R2 0.134, P=0.002) in the initial 6 months only. Insulin therapy leads to weight gain (2.8 kg), predominantly fat-free mass, over 12 months. After 6 months, newly treated patients continued gaining weight despite an unchanged HbA1c, suggesting the potential anabolic role of insulin in subsequent gains. Therefore, in the initial 6 months, weight gain can be attributed to a 'glucose control-related effect' and further gain appears to be due to a 'non-glucose control-related' effect of insulin treatment.

Adipose Tissue↗
PubMed2005

A comparison of fast MRI of hips with and without parallel imaging using SENSE.

This study was undertaken to qualitatively and quantitatively compare fast MRI of hips with and without parallel imaging using SENSE (sensitivity encoding). 27 patients underwent MRI of the hips with coronal T1 turbo spin echo (TSE) (repetition time (TR) 500 ms, effective echo time (TEeff) 15 ms, Turbo Factor 4), coronal IR-TSE (TR 2000 ms, TEeff 30 ms, inversion time (TI) 160 ms, Turbo Factor 20) and axial T2 TSE (TR 3000 ms, TEeff 80 ms, Turbo Factor 20) weighted images acquired with and without SENSE with a reduction factor of 2. Conventional imaging was performed in 8 min and 36 s. Images acquired with SENSE were acquired in 5 min and 31 s without a discernible reduction in image quality or a significant quantitative reduction in image signal to noise ratio, contrast to noise ratio or edge enhancement.

Adult↗
PubMed2005

A prospective study of the effectiveness of group and individual psychotherapy for women CSA survivors.

OBJECTIVES: There is little empirical evidence to guide clinical practice in treating adult patients presenting to adult mental health and primary care services with severe psychological difficulties consequent on childhood sexual abuse. The aim of this study was to determine the effectiveness of a model of short term, focal, integrative psychotherapy with this population of patients and to compare outcomes when the model is delivered on an individual or group basis. DESIGN: This study used a patient preference design with random allocation to one of two treatment modalities (individual or group treatment). There was a waiting list control. METHOD: A group of 48 women patients were assessed on 4 psychological measures when entering a waiting list condition, immediately before treatment and after completion of 12 sessions of psychotherapy, either in a group or individually. Follow-up data were collected at 4 months and 8 months. RESULTS: Both individual and group patients showed highly statistically and clinically significant improvements after treatment. These gains were maintained at follow-up with the exception of one measure that indicated a significant decline from post-treatment levels for the group patients. CONCLUSIONS: This model of psychotherapy is highly effective, when delivered by chartered clinical psychologists to patients whose preferences for individual or group therapy have been met.

Adult↗
PubMed2004

Case management of a multidrug-resistant Shigella dysenteriae serotype 1 outbreak in a crisis context in Sierra Leone, 1999-2000.

From December 1999 to the end of February 2000, 4218 cases of dysentery were reported in Kenema district, southeastern Sierra Leone, by a Médecins Sans Frontières team operating in this region. Shigella dysenteriae serotype 1 was isolated from the early cases. The overall attack rate was 7.5% but higher among children under 5 years (11.2%) compared to the rest of the population (6.8%) (RR = 1.6; 95% CI 1.5-1.8). The case fatality ratio was 3.1%, and higher for children under 5 years (6.1% vs. 2.1%) (RR = 2.9; 95% CI 2.1-4.1). A case management strategy based on stratification of affected cases was chosen in this resource-poor setting. Patients considered at higher risk of death were treated with a 5 day ciprofloxacin regimen in isolation centres. Five hundred and eighty-three cases were treated with a case fatality ratio of 0.9%. Patients who did not have signs of severity when seen by health workers were given hygiene advice and oral rehydration salts. This strategy was effective in this complex emergency.

Adolescent↗
PubMed2004

Whole body magnetic resonance imaging in the diagnosis of Parsonage Turner syndrome.

PURPOSE: To describe magnetic resonance imaging (MRI) findings in patients with suspected Parsonage Turner syndrome and to emphasize the value of an additional whole body MR scan to improve specificity of this diagnosis. MATERIAL AND METHODS: Three patients with proven Parsonage Turner syndrome referred for conventional MRI of the shoulder girdle and additional whole body turboSTIR MRI were included for study. RESULTS: In each case, imaging revealed edema in the muscles of the shoulder girdle. Whole body turboSTIR MRI scan confirmed localized unilateral changes in each case improving specificity and confidence in the diagnosis of Parsonage Turner syndrome in each case. CONCLUSION: Whole body turboSTIR MR imaging is a useful diagnostic tool in the evaluation of patients with suspected Parsonage Turner syndrome. Inclusion of the brain, neck, brachial plexus, and extremity musculature at whole body imaging allows differentiation from polymyositis and elimination of additional causes of shoulder girdle pain and weakness including gross lesions in the brain, neck, and brachial plexus by a single non-invasive study.

Brachial Plexus Neuritis↗
PubMed2004

Eliciting preferences for drug treatment of lower urinary tract symptoms associated with benign prostatic hyperplasia.

PURPOSE: There are 2 main medical preparations available for lower urinary tract symptoms resulting from benign prostatic hyperplasia (BPH). Choosing between an alpha-blocker and a 5alpha-reductase inhibitor requires trade-offs between their attributes or characteristics. We investigated the relative importance of and trade-offs between the attributes of the 5alpha-reductase inhibitor dutasteride and alpha-blockers in community dwelling men using a validated technique. MATERIALS AND METHODS: A discrete choice experiment was administered to 211 men older than 40 years who were randomly selected from the general United Kingdom population. Attributes investigated in the discrete choice experiment were time to symptom improvement, sexual and nonsexual side effects, the risks of acute urinary retention (AUR) and surgery, cost and prostate size decrease. Using regression analysis the relative importance of these attributes, the trade-offs that men are willing to make between these attributes and the willingness to pay for each attribute were estimated. RESULTS: All attributes were important to respondents. The most important attribute was side effects. The least preferred side effects was impotence, followed by decreased libido and dizziness. Respondents were willing to wait 13, 2 and 8 months longer for symptom improvement in exchange for decreased prostate size, and the risks of AUR and surgery, respectively. Men reporting moderate symptoms were less concerned about sexual side effects, time to symptom improvement and the risk of AUR compared with men reporting mild symptoms. CONCLUSIONS: Given the attribute levels of BPH medical treatment, overall community dwelling men preferred the 5alpha-reductase inhibitor over alpha-blockers. In the interests of shared decision making it is important to consider the importance of eliciting the preferences of patients with BPH.

Adrenergic alpha-Antagonists↗