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Biomedical subjects

N Hudson

Publications and source records attributed to N Hudson.

At least 19 recordsLinked to original sources
PubMed2003

The relation between Ashworth scale scores and the excitability of the alpha motor neurones in patients with post-stroke muscle spasticity.

BACKGROUND: The modified Ashworth scale (MAS) is the most widely used method for assessing muscle spasticity in clinical practice and research. However, the validity of this scale has been challenged. OBJECTIVES: To compare the MAS with objective neurophysiological tests of spasticity. METHODS: The MAS was recorded in patients with post-stroke lower limb muscle spasticity and correlated with the excitability of the alpha motor neurones. The latter was evaluated by measuring the latency of the Hoffmann reflex (H reflex) and the ratio of the amplitude of the maximum H reflex (H(max)) to that of the compound action motor potential of the soleus muscle (M(max)). RESULTS: Data on 24 randomly recruited patients were analysed. Patients were divided into two groups according to their MAS score: 14 had a MAS score of 1 (group A) and 10 scored 2 (group B). The two groups were comparable with respect to age and sex, but in group A there was a longer period since the stroke. The H reflex latency was reduced and the H(max):M(max) ratio was increased in both groups. The H(max):M(max) ratio values were higher for group B but the differences were not statistically significant. CONCLUSIONS: There is a relation between the MAS scores and alpha motor neurone excitability, although it is not linear. This suggests that the MAS measures muscle hypertonia rather than spasticity.

Action Potentials↗
PubMed2001

A reduction in interstitial cells of Cajal in horses with equine dysautonomia (grass sickness).

Equine dysautonomia (grass sickness) is a common, frequently fatal disease of horses characterised by dysfunction of the gastrointestinal tract. Interstitial cells of Cajal are the c-Kit-immunoreactive cells responsible for the generation of pacemaker activity in gastrointestinal smooth muscle. Impairment of this pacemaker action has been implicated in several motility disorders in humans and laboratory mammals. The aim of this study was to test the hypothesis that changes in interstitial cells of Cajal may be involved in the pathophysiology of the intestinal dysfunction observed in equine grass sickness. Interstitial cells of Cajal were identified using immunohistochemical labelling with an anti-c-Kit antibody and their density was assessed using a semi-quantitative grading system. Segments of ileum were examined from 24 horses free from gastrointestinal disease and compared to tissues from 28 horses with grass sickness. Segments of the pelvic flexure region of the large colon were examined from 13 horses free from gastrointestinal disease and compared to tissues from 10 horses with grass sickness. In horses with grass sickness, interstitial cells of Cajal were significantly decreased in both the myenteric plexus and circular muscle regions of both ileum and pelvic flexure compared to normal animals. Therefore, it is possible that the decline in interstitial cells of Cajal may be an important factor in the development of intestinal dysmotility observed in grass sickness.

Acute Disease↗
PubMed2001

Multicentre, prospective, randomized trial of 4 vs. 6 French catheters in 410 patients undergoing coronary angiography.

The aim of this study was to assess the quality of angiograms obtained using 4 Fr catheters compared with 6 Fr catheters, the ease of use of the 4 Fr catheters, and the safety of patient mobilization 1 hr following 4 Fr angiography. Details of catheter performance and procedural details were recorded at the time of the angiogram. The angiographic images were scored on the quality and completeness of vessel opacification throughout systole and diastole. A total of 410 patients were recruited. There was no difference between 4 and 6 Fr for procedural variables. All angiograms were considered to be of diagnostic quality. The angiographic scores for the right coronary artery and left ventricular injections were no different between 4 and 6 Fr. However, the angiographic scores for the left anterior descending and circumflex arteries were lower with 4 than with 6 Fr (both P < 0.05). Patients who had 4 Fr angiography mobilized safely at 1 hr and reported significantly less discomfort and bruising than 6 Fr patients. Good-quality diagnostic coronary angiograms can be achieved using 4 Fr catheters with the advantage of earlier postprocedural mobilization and reduced discomfort and bruising for the patient.

Aged↗
PubMed2001

Sequencing batch reactor technology: the key to a BP refinery (Bulwer Island) upgraded environmental protection system--a low cost lagoon based retro-fit.

BP Refinery (Bulwer Island) Ltd (BP) located on the eastern Australian coast is currently undergoing a major expansion as a part of the Queensland Clean Fuels Project. The associated wastewater treatment plant upgrade will provide a better quality of treated effluent than is currently possible with the existing infrastructure, and which will be of a sufficiently high standard to meet not only the requirements of imposed environmental legislation but also BP's environmental objectives. A number of challenges were faced when considering the upgrade, particularly; cost constraints and limited plot space, highly variable wastewater, toxicity issues, and limited hydraulic head. Sequencing Batch Reactor (SBR) Technology was chosen for the lagoon upgrade based on the following; SBR technology allowed a retro-fit of the existing earthen lagoon without the need for any additional substantial concrete structures, a dual lagoon system allowed partial treatment of wastewaters during construction, SBRs give substantial process flexibility, SBRs have the ability to easily modify process parameters without any physical modifications, and significant cost benefits. This paper presents the background to this application, an outline of laboratory studies carried out on the wastewater and details the full scale design issues and methods for providing a cost effective, efficient treatment system using the existing lagoon system.

Bioreactors↗
PubMed2001

Laboratory investigation of supported permeable organic covers for the management of odour emissions from anaerobic piggery waste ponds.

Australian research has linked much of the odour arising from intensive livestock operations to pond treatment systems. A reduction in emissions from treatment ponds would therefore generally reduce odour emissions from intensive livestock operations. Published data indicates that the application of straw and other biological materials to effluent pond surfaces as a continuous cover reduces odour emissions. The effectiveness of these covers has not, however, been researched under controlled conditions. Using locally available materials, the efficacy of supported covers has been investigated using a series of laboratory anaerobic digesters treating typical piggery effluent. Research to date has focused on: identifying effective cover and cover support materials; quantifying odour reduction; identifying the impact use these covers may have on greenhouse gas emissions; devising practical and effective methods for constructing these covers. Results have confirmed that a variety of cover materials are effective in reducing pond odour emissions. Supporting the pond cover appears to extend the cover life expectancy. While greenhouse gas emissions appear to vary according to cover type, the overall significance of these emissions is not yet clear. The impact of permeable pond covers on overall pond performance requires additional research.

Agriculture↗
PubMed2000

Randomised placebo controlled trial of nebulised corticosteroids in acute respiratory syncytial viral bronchiolitis.

OBJECTIVE: To evaluate short and long term effects of giving nebulised budesonide early in respiratory syncytial viral (RSV) bronchiolitis. DESIGN: A multicentre randomised double blind placebo controlled trial. SUBJECTS: Infants admitted to hospital with their first episode of RSV positive bronchiolitis. INTERVENTION: Randomisation to receive either 1 mg of nebulised budesonide (Bud) or placebo (Pla) twice daily from admission until 2 weeks after discharge. Follow up was for 12 months. MAIN OUTCOME MEASURES: Duration of hospital admission, time taken to become symptom free, re-admission rates, general practitioner consultation rates, and use of anti-wheeze medication during follow up. RESULTS: 161 infants were studied. Both arms were similar with respect to initial clinical severity, age, sex, socioeconomic class, and tobacco exposure. Median time from first nebulisation to discharge: Bud and Pla, 2 days. Median number of days for 50% of infants to be symptom free for 48 hours: Bud, 10 days; Pla, 12 days. Respiratory re-admission rates in the 12 month follow up: Bud, 16%; Pla, 18%; median difference (95% confidence interval (CI)), -2 (-14 to 10). Median respiratory related general practitioner attendances: Bud, 4.0; Pla, 4.5; median difference (95% CI), -1 (-2 to 0). Percentage of infants receiving at least one prescription for anti-wheeze medication during follow up, corticosteroids: Bud, 50%; Pla, 60%; difference (95% CI), -10 (-26 to 6); bronchodilators: Bud, 60%; Pla, 67%; difference (95% CI), -7 (-22 to 8). CONCLUSIONS: There are no short or long term clinical benefits from the administration of nebulised corticosteroids in the acute phase of RSV bronchiolitis.

Acute Disease↗
PubMed1999

Neutrophils, Helicobacter pylori, and nonsteroidal anti-inflammatory drug ulcers.

BACKGROUND & AIMS: Gastric injury by nonsteroidal anti-inflammatory drugs (NSAIDs) is minimal in neutropenic animals. This study examined peptic ulcer development in the presence or absence of gastric neutrophils in patients requiring long-term use of NSAIDs. METHODS: Gastric histology, neutrophils, and Helicobacter pylori were assessed in 120 patients randomized to receive placebo or 20 or 40 mg famotidine twice daily as prophylaxis against NSAID-related ulcers and who underwent endoscopy at 0, 4, 12, and 24 weeks. RESULTS: In 43 patients without gastric neutrophils, ulcers developed in 1 of 14 (7.7%) taking placebo, 2 of 16 (12.5%) taking 20 mg famotidine, and none of 13 taking 40 mg famotidine. However, in 77 patients with neutrophils, ulcers developed in 13 of 28 (47. 4%) taking placebo (P < 0.001), 3 of 26 (12.6%) taking 20 mg famotidine, and 3 of 23 (13%) taking 40 mg famotidine. Eight of 46 patients (17%) without H. pylori had neutrophils compared with 69 of 74 (93%) with both H. pylori and neutrophils (P < 0.001). CONCLUSIONS: Gastric neutrophils increase the incidence of ulceration in long-term NSAID users. Because neutrophils exist with H. pylori, eradicating this infection might prevent NSAID-related peptic ulcers.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1999

Protection of human gastric mucosa against aspirin-enteric coating or dose reduction?

BACKGROUND: Aspirin is widely used for cardiovascular prophylaxis. AIM: To compare the effectiveness of two widely-used strategies-dose reduction and enteric coating-for the minimization of gastric mucosal injury or toxicity. METHODS: Twelve healthy volunteers were studied. On four separate occasions each received, under blinded conditions, five daily doses of plain aspirin 300 mg, plain aspirin 75 mg, enteric-coated aspirin 300 mg or placebo. Ex vivo prostaglandin E2 synthesis was stimulated by the vortex mixing of gastric mucosal biopsies in Tris saline and measured by radioimmunoassay. Mucosal injury was quantified both by counting erosions and with a visual analogue scale. RESULTS: All three preparations reduced prostaglandin E2 synthesis by day five, by (median) 84% for plain aspirin 300 mg, by 80% for enteric coated aspirin 300 mg and by 63% for plain aspirin 75 mg. There was little mucosal injury prior to the start of each dose and period and no significant change with placebo. Plain aspirin caused a dose-dependent mucosal injury, with two (median, IQR 0-7) gastric erosions after five days of plain aspirin 75 mg, and 18 (2-26) after five days of plain aspirin 300 mg. With enteric-coated aspirin 300 mg there were 0 (0-1) gastric erosions (P = 0.003 compared to plain aspirin 300 mg P = 0.11, compared to plain aspirin 75 mg). CONCLUSION: Enteric coated aspirin reduces acute gastric mucosal injury to placebo levels, despite its inhibition of prostaglandin synthesis. Enteric coating is an appropriate strategy for the prevention of gastric mucosal damage induced by low-dose aspirin, which warrants systematic clinical evaluation.

Adult↗
PubMed1998

Non-rabies Lyssavirus human encephalitis from fruit bats: Australian bat Lyssavirus (pteropid Lyssavirus) infection.

A 39-year-old woman died of encephalitis a few weeks after being scratched by fruit bats. Autopsy disclosed meningoencephalomyelitis, and revealed neuronal intracytoplasmic inclusions which had similarities to Negri bodies of rabies. Laboratory investigations detected a Lyssavirus type previously identified only in fruit bats. This appears to be the first human case of encephalitis due to this Lyssavirus type.

Adult↗
PubMed1998

The association of soft-tissue rheumatism and hypermobility.

Soft-tissue rheumatism (STR--tendinitis, bursitis, fasciitis and fibromyalgia) accounts for up to 25% of referrals to rheumatologists. The estimated prevalence of generalized hypermobility in the adult population is 5-15%. There have previously been suggestions that hypermobile individuals may be predisposed to soft-tissue trauma and subsequent musculoskeletal pain. This study was designed to examine the mobility status and physical activity level in consecutive rheumatology clinic attendees with a primary diagnosis of STR. Of 82 patients up to age 70 yr with STR, 29 (35%) met criteria for generalized hypermobility. Hypermobile compared to non-hypermobile individuals reported significantly more previous episodes of STR (90% vs 51%, P < 0.01), and more recurrent episodes of STR at a single site (69% vs 38%, P < 0.001). Although we were unable to show any difference in the time spent carrying out physical activity between the two groups, the hypermobile patients were performing significantly more repetitive activities. When specific anatomical sites of STR were analysed, small joints (elbows, hands and feet) currently affected with STR were more likely to show localized hypermobility than if those joints were asymptomatic. These findings suggest that hypermobility may be a factor in the development of STR. Repetitive activity may be a contributing factor towards STR in some hypermobile individuals.

Adolescent↗
PubMed1998

Steroid contents of and steroidogenesis in vitro by the developing gonad and mesonephros around sexual differentiation in fetal sheep.

The aim of the present study was to establish whether the steroids, progesterone, androstenedione, testosterone and oestradiol, were present in the mesonephric-gonadal complex of female and male sheep fetuses around sexual differentiation (that is, from day 28 to day 45 of gestation, with sexual differentiation occurring at approximately day 32). A second aim was to test whether the mesonephric-gonadal complex, mesonephros (days 35-45 only) and gonad (days 35-45 only) were capable of steroid synthesis in vitro. The steroid contents in the mesonephric-gonadal complex were not detectable before sexual differentiation. However, from day 35 of gestation onwards, the mesonephric-ovarian complex contained mainly oestradiol and the mesonephric-testicular complex contained mainly testosterone: from day 35 until day 45 the increase in content of these two steroids exceeded the increase in the mass of tissue by more than fivefold. From day 40 to day 45 of gestation, the contents of the other steroids in the pathways to oestradiol increased progressively in both sexes but more in parallel with the increase in tissue mass. In contrast to the steroid contents in the tissue at recovery, the mesonephric-gonadal tissue from both sexes in tissue culture was able to synthesize most steroids before and after sexual differentiation and also to metabolise supplementary androstenedione to oestradiol. These findings suggest that many, if not all, of the steroidogenic enzymes in the pathway from cholesterol to oestradiol are present before sexual differentiation. Most of the aforementioned steroids were present in detectable amounts in isolated mesonephros and gonad of both sexes after sexual differentiation. Moreover, for both the isolated mesonephros and gonad, there were increases in the mean contents of most steroids after culture relative to the contents in the tissues at recovery. These data suggest that the mesonephros, as well as the gonad, in both sexes is capable of synthesizing steroid. It is concluded that, in the sheep fetus, the female and male gonads are steroidogenically active after sexual differentiation, that the steroidogenic enzymes develop before sexual differentiation, and that the mesonephros is a site of steroid synthesis.

Androstenedione↗
PubMed1997

Famotidine for healing and maintenance in nonsteroidal anti-inflammatory drug-associated gastroduodenal ulceration.

BACKGROUND & AIMS: Nonsteroidal anti-inflammatory drugs (NSAIDs) are strongly associated with gastroduodenal ulceration. How to manage patients with NSAID-associated ulcers is a common clinical dilemma. High-dose famotidine in the healing and maintenance of NSAID-associated gastroduodenal ulceration was therefore evaluated. METHODS: One hundred four patients with rheumatoid or osteoarthritis who had gastroduodenal ulceration received famotidine, 40 mg twice daily. Sixteen patients stopped and 88 continued their NSAID treatment. Ulcer healing was assessed endoscopically at 4 and 12 weeks. Seventy-eight NSAID users with healed ulcers were then randomized to receive 40 mg twice daily famotidine or placebo and underwent endoscopy at 4, 12, and 24 weeks. RESULTS: Cumulative ulcer healing rates at 12 weeks were 89.0% (95% confidence interval [CI], 82.3%-95.7%) for patients who continued NSAID treatment and 100% (95% CI, 82.9%-100.0%) for those who stopped. The subsequent estimated cumulative gastroduodenal ulcer relapse over 6 months for NSAID users who took placebo was 53.5% (95% CI, 36.6%-70.3%). This was reduced to 26.0% (12.1%-39.9%) in patients taking famotidine (P = 0.011). CONCLUSIONS: High-dose famotidine is effective ulcer healing therapy in patients who stop or continue NSAID treatment and significantly reduced the cumulative incidence of gastroduodenal ulcer recurrence compared with placebo when given as maintenance therapy.

Adult↗
PubMed1997

Effect of sucralfate on aspirin induced mucosal injury and impaired haemostasis in humans.

BACKGROUND: Sucralfate does not have potent anti-ulcerogenic actions in users of non-steroidal anti-inflammatory drugs (NSAIDs). However, sucralfate may influence intragastric haemostasis favourably. AIM: To investigate separately the effects of sucralfate on acute gastric and duodenal injury and on changes in intragastric bleeding induced by aspirin. METHOD: On three occasions, 24 healthy volunteers received three days' treatment with aspirin 900 mg twice daily together with placebo, sucralfate 2 g twice daily or sucralfate 1 g four times daily. Injury was assessed endoscopically and bleeding by spontaneous and biopsy induced bleeding intragastric washings. Ex vivo prostaglandin E2 (PGE2) synthesis and serum thromboxane were measured by using radioimmunoassay. RESULTS: Aspirin significantly inhibited ex vivo gastric mucosal PGE2 synthesis, reduced serum thromboxane, caused gastric erosions, and increased spontaneous and biopsy induced bleeding. Sucralfate had no significant effects on endoscopic injury but sucralfate 1 g four times daily significantly reduced spontaneous and biopsy induced bleeding. Similar trends were seen with sucralfate 2 g twice daily but the results were less consistent. CONCLUSION: Sucralfate does not affect aspirin induced acute gastric mucosal injury but reduces aspirin associated intragastric bleeding.

Acute Disease↗
PubMed1997

Catastrophic haemorrhage in a case of paediatric primary antiphospholipid syndrome and factor II deficiency.

The first case of primary antiphospholipid syndrome associated with recurrent life-threatening haemorrhages, due to the coexistence of acquired prothrombin deficiency, is described. Attention is drawn to the difficulty in diagnosing this situation, and therapeutic options are reviewed. Evidence is presented that implicates prothrombin as the protein cofactor for this lupus anticoagulant.

Adolescent↗