Effective treatment of severe facial dermatitis in lambs.
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Biomedical subjects
Publications and source records attributed to G Bell.
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DESIGN: Longitudinal training. OBJECTIVES: The purpose was to determine the effect of electrical stimulation (ES)-assisted cycling (30 min/day, 3 days/week for 8 weeks) on glucose tolerance and insulin sensitivity in people with spinal cord injury (SCI). SETTING: The Steadward Centre, Alberta, Canada. METHODS: Seven participants with motor complete SCI (five males and two females aged 30 to 53 years, injured 3-40 years, C5-T10) underwent 2-h oral glucose tolerance tests (OGTT, n=7) and hyperglycaemic clamp tests (n=3) before and after 8 weeks of training with ES-assisted cycling. RESULTS: Results indicated that subjects' glucose level were significantly lower at 2 h OGTT following 8 weeks of training (122.4+/-10 vs 139.9+/-16, P=0.014). Two-hour hyperglycaemic clamps tests showed improvement in all three people for glucose utilisation and in two of three people for insulin sensitivity. CONCLUSIONS: These results suggested that exercise with ES-assisted cycling is beneficial for the prevention and treatment of Type 2 diabetes mellitus in people with SCI. SPONSORSHIP: Supported by Alberta Paraplegic Foundation, Therapeutic Alliance.
The central themes of community ecology-distribution, abundance, and diversity-display strongly marked and very general patterns. These include the log-normal distribution of abundance, the relation between range and abundance, the species-area law, and the turnover of species composition. Each pattern is the subject of a large literature that interprets it in terms of ecological processes, typically involving the sorting of differently specialized species onto heterogeneous landscapes. All of these patterns can be shown to arise, however, from neutral community models in which all individuals have identical properties, as the consequence of local dispersal alone. This implies, at the least, that functional interpretations of these patterns must be reevaluated. More fundamentally, neutral community models provide a general theory for biodiversity and conservation biology capable of predicting the fundamental processes and patterns of community ecology.
STUDY DESIGN: An Institutional Review Board-approved Phase I efficacy study of inflatable bone tamp usage in the treatment of symptomatic osteoporotic compression fractures. OBJECTIVES: To evaluate the safety and efficacy of inflatable bone tamp reduction and cement augmentation, "kyphoplasty," in the treatment of painful osteoporotic vertebral compression fractures. SUMMARY OF BACKGROUND DATA: Osteoporotic compression fractures can result in progressive kyphosis and chronic pain. Traditional treatment for these patients includes bed rest, analgesics, and bracing. Augmentation of vertebral compression fractures with polymethylmethacrylate, "vertebroplasty," has been used to treat pain. This technique, however, makes no attempt to restore the height of the collapsed vertebral body. Kyphoplasty is a new technique that involves the introduction of inflatable bone tamps into the vertebral body. Once inflated, the bone tamps restore the vertebral body back toward its original height while creating a cavity that can be filled with bone cement. PATIENTS AND METHODS: Seventy consecutive kyphoplasty procedures were performed in 30 patients. The indications included painful primary or secondary osteoporotic vertebral compression fractures. Mean duration of symptoms was 5.9 months. Symptomatic levels were identified by correlating the clinical data with MRI findings. Perioperative variables and bone tamp complications or issues were recorded and analyzed. Preoperative and postoperative radiographs were compared to calculate the percentage height restored. Outcome data were obtained by comparing preoperative and latest postoperative SF-36 data. RESULTS: At the completion of the Phase I study there were no major complications related directly to use of this technique or use of the inflatable bone tamp. In 70% of the vertebral bodies kyphoplasty restored 47% of the lost height. Cement leakage occurred at six levels (8.6%).SF-36 scores for Bodily Pain 11.6-58.7, (P = 0.0001) and Physical Function 11.7-47.4, (P = 0.002) were among those that showed significant improvement. CONCLUSIONS: The inflatable bone tamp was efficacious in the treatment of osteoporotic vertebral compression fractures. Kyphoplasty is associated with early clinical improvement of pain and function as well as restoration of vertebral body height in the treatment of painful osteoporotic compression fractures.
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Unicellular, motile, phototropic green algae were extracted from soil samples taken at metre intervals along a 25-m transect in a wheat field. The vegetative growth of 61 randomly selected isolates (henceforth called spores) was measured in dark and light conditions, and at high and low nutrient concentrations in liquid media. The among-spore variance was dominated by a spore-by-environment interaction. The increase of among-spore variance with distance was detectable but slight, showing that most of the diversity found on the transect was present at a scale of metres. A mixture of all spores, constituting the founder assemblage, was propagated for 50-70 generations in three environments to study the sorting of variation initially present in the assemblage. Adaptation to the new environments was measured by improvement in growth relative to the founder assemblage. All three sets of lines became adapted to their selection environment, although the extent of the advance depended on the amount of among-spore variance in the founder assemblage. Selection for increased growth in the dark, or at high nutrient conditions in the light, caused the assemblage to evolve to the limit of the variation initially present, strongly reducing among-spore variance as a consequence. At low nutrient concentrations selection was less effective, and there was little reduction of the among-spore variance. The correlated responses of each group, again relative to the founder assemblage, were measured over the entire experimental range. Correlated responses were negative when performance in widely different (light and dark) environments was compared, but positive for more similar environments (high and low nutrient concentrations).
We aimed to assess the efficacy of a screen and treat policy for sexually transmitted infections in women requesting termination of pregnancy, with particular reference to Chlamydia trachomatis. A retrospective review of 100 consecutive cases of Chlamydia-positive women between December 1995 and February 1998, was performed. The referral rate to genitourinary medicine (GUM), the subsequent management, contact tracing and treatment of partners were assessed. Ninety-nine women were referred to the GUM department, of whom 72 (71.4%) attended. Eighteen (25%) required further treatment. Seventy-five women identified 89 potentially infected men, of whom 62 (69%) attended for treatment. Identification of positive cases with referral to GUM enabled tests of cure to be carried out, treatment of those reinfected and re-enforcement of behaviour modification, in addition to successful contact tracing. This policy may confer greater benefit for the patient herself and make a significant impact on the reservoir of infection in the community when compared to a policy of blanket prophylactic antibiotic treatment at the time of termination. The implications for future service provision are discussed.
The health benefits and quality-of-life outcomes of a fit musculoskeletal system (musculoskeletal fitness) are reviewed in this article. The World Health Organization suggests health is a state of complete physical, mental or social well-being and not merely the absence of disease or infirmity. Physical health includes such characteristics as body size and shape, sensory acuity, susceptibility to disease and disorders, body functioning, recuperative ability and the ability to perform certain tasks. One aspect of physical health is the musculoskeletal system, which consists of 3 components; muscular strength, endurance and flexibility. Muscular strength (dynamic) is defined as the maximum force a muscle or muscle group can generate at a specific velocity. Muscular endurance is the ability of a muscle or muscle group to perform repeated contractions against a load for an extended period of time. Flexibility has 2 components, dynamic or static, where dynamic flexibility is the opposition or resistance of a joint to motion, that is, the forces opposing movement rather than the range of movement itself. Static flexibility is the range of motion about ajoint, typically measured as the degree of arc at the end of joint movement. If strength, endurance and flexibility are not maintained, musculoskeletal fitness is then compromised which can significantly impact physical health and well-being. Many health benefits are associated with musculoskeletal fitness, such as reduced coronary risk factors, increased bone mineral density (reduced risk of osteoporosis), increased flexibility, improved glucose tolerance, and greater success in completion of activities of daily living (ADL). With aging, the performance of daily tasks can become a challenge. Additionally, falls, bone fractures and the need for institutional care indicate a musculoskeletal weakness as we age. The earlier in life an individual becomes physically active the greater the increase in positive health benefits; however, becoming physically active at any age will benefit overall health. Improved musculoskeletal fitness (for example, through resistance training combined with stretching) is associated with an enhanced health status. Thus, maintaining musculoskeletal fitness can increase overall quality of life.
Allelic variation in the size of the insulin (INS) variable number tandem repeat (VNTR) correlates with the expression of both INS in the pancreas and thymus and IGF2 (the gene downstream of INS) in the placenta. In addition, the shorter, class I alleles are associated with type 1 diabetes, whereas the longer, class III alleles are associated with type 2 diabetes, polycystic ovary syndrome (PCOS), and size at birth. Parent-of-origin effects have been reported for type 2 diabetes and PCOS, thus implicating a role for genomic imprinting in these phenotypes. In mice, Ins2 is imprinted and paternally expressed in the yolk sac. In humans, evidence for the imprinting of INS is circumstantial, with occasional monoallelic expression in the thymus. In the present study, we found evidence for the imprinted paternal expression of INS in the human yolk sac. Two other imprinted genes from the same cluster are also expressed monoallelically in the human yolk sac. IGF2 was expressed solely from the paternal allele, and H19 was expressed solely from the maternal allele. These data suggest not only further functional roles for the human yolk sac in early fetal growth, but also evidence for a potential causal link between the control of insulin expression during development and insulin/growth-related diseases in later life.
BACKGROUND: Gonorrhoea is a common infectious disease, poorly controlled despite effective treatments. Tracing chains of transmission is difficult, because sexual partners are commonly difficult or impossible to identify. We assess the use of gonococcal opa-typing in identifying transmission links not revealed through interview. METHODS: Epidemiological data and gonococcal isolates were collected prospectively from patients at two UK clinics in London and Sheffield. Social and epidemiological data were combined with molecular typing of gonococcal isolates by a new methodology based on the polymorphisms of the opa gene. FINDINGS: In London, interview data and opa-typing on samples from 215 cases showed a diverse population with few links. In Sheffield, interview data identified links between 51 (43%) of 120 cases, whereas opa-typing suggested a more connected population: 95 (79%) of cases had shared profiles. There was a highly significant correlation between the two distributions with epidemiological clusters appearing as a subset of the opa clusters. Two large opa clusters, of 18 and 43 cases, accounted for 50% of local cases of gonorrhoea. Discordance between epidemiological and opa-typing data was observed at highly connected points in the sexual network. INTERPRETATION: Opa-typing is a more powerful tool for epidemiological investigation of gonorrhoea transmission than earlier methods. Opa-typing can link infections that would otherwise remain unlinked, and may aid interventions to control endemic disease.
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The species diversity of natural communities is often strongly related to their productivity. The pattern of this relationship seems to vary: diversity is known to increase monotonically with productivity, to decrease monotonically with productivity, and to be unimodally related to productivity, with maximum diversity occurring at intermediate levels of productivity. The mechanism underlying these patterns remains obscure, although many possibilities have been suggested. Here we outline a simple mechanism--involving selection in a heterogeneous environment--to explain these patterns, and test it using laboratory cultures of the bacterium Pseudomonas fluorescens. We grew diverse cultures over a wide range of nutrient concentrations, and found a strongly unimodal relationship between diversity and productivity in heterogeneous, but not in homogeneous, environments. Our result provides experimental evidence that the unimodal relationship often observed in natural communities can be caused by selection for specialized types in a heterogeneous environment.
Resistance training (RT) has gained popularity as an effective form of exercise for older adults. However, the effects of RT on left ventricular (LV) morphology and systolic function in older persons is not well known. The purpose of this study was to assess the effects of 16 weeks of RT on LV morphology and systolic function in healthy older men. Subjects were randomly assigned into a RT group (n = 10; mean+/- SD age, 68 +/- 3 years) or a nonexercise control group (n = 10; age 68 +/- 4 years). RT was performed 3 times per week for 16 weeks at a mean intensity between 60% and 80% of 1 repetition maximum. Leg and bench press 1 repetition maximum and 2-dimensional echocardiography were performed at baseline and after 4, 8, 12, and 16 weeks of training in the RT group. Sixteen weeks of RT was associated with an increase in leg press maximal strength (baseline, 285 +/- 48 kg; after 16 weeks, 367 +/- 47 kg; p <0.05) and bench press maximal strength (baseline, 59 +/- 11 kg; after 16 weeks, 69 +/- 11 kg; p <0.05). No change in leg press maximal strength (baseline, 291 +/- 59 kg; after 16 weeks, 290 +/- 53 kg; p >0.05) or bench press maximal strength (baseline, 60 +/- 9 kg; after 16 weeks, 61 +/- 13 kg; p > .05) was found in control subjects during the same time. RT was not associated with changes in LV cavity size, wall thickness, mass, or systolic function after 4, 8, 12, and 16 weeks of exercise. Thus, 16 weeks of RT was sufficient to increase leg press and bench press maximal strength but did not alter the size or systolic function of the senescent left ventricle.
Heat shock protein-based vaccines have been shown to immunize against cancer and infectious diseases in both prophylactic and therapeutic protocols. So far, four classes of heat shock proteins (HSPs) preparation: gp96, HSP90 (hsp86, hsp84), HSP70 (hsc70, hsp70) and calreticulin have been used successfully. The methods for purifying them individually are now readily available. However, since tumors are not always available in large quantity, a major challenge remains the development of a procedure to simultaneously isolate these HSPs from the same sample. We report here that hsp40, hsp60, hsc70, hsp70, hsp84, hsp86, and gp96 (grp94) but not BiP (grp78) and calreticulin can be separated from a single tumor sample in one step using heparin-agarose chromatography. Interestingly this procedure separates the HSP70 isoforms hsp70 from hsc70, but not the HSP90 isoforms hsp84 and hsp86. The three main immunogenic HSPs, gp96, hsp86/84, and hsc70 can be further isolated to homogeneity using additional purification methods. In addition, we have shown that the interaction of the chaperoned peptides with hsc70 and gp96 is not compromised during heparin chromatography. These observations provide a new method for preparation of multiple HSP-based vaccines, circumventing the sample size limitation, as well as providing the possibility to study how multiple HSPs can synergize in eliciting immunity.
We studied the inactivation of trypsin and alpha- and beta-chymotrypsin by passage of droplets of tridecane though their aqueous solutions. The mechanism involves contact with the interface, because the loss of activity is proportional to the total area exposed. The rates of inactivation vary up to fivefold over the pH range 3 to 10. However, there is no clear maximum at the isoelectric point (pI) of each enzyme, where the amount of protein adsorbed is usually found to be highest. This is probably because, at the pI, there is also a minimum in structural alteration on adsorption. There may be a weak correlation with pH effects on foamability of the enzyme solutions, a parameter reported to reflect the "hardness" of different proteins, which controls their interfacial unfolding. The pH dependence of both inactivation and hardness cautions against attempts to correlate inactivation of different enzymes with a single value of a parameter such as adiabatic compressibility. There is no correlation between the effects of pH on interfacial inactivation and those reported in the literature on irreversible inactivation in concentrated urea or at high temperature.
Cultures of Chlamydomonas were exposed to a range of relatively mild stresses for a period of 24 h. These stresses comprised high and low temperatures, osmotic stress, low pH, starvation and toxic stress. They were then allowed to recuperate for around ten vegetative generations under near-optimal conditions in unmodified minimal medium. Fitness was then assayed as the rate of division of isolated cells on agar. We found that there was a strong tendency for stressed cultures to have lower mean fitness and greater standardized variance in fitness than the negative controls which had been cultured throughout in unmodified minimal medium. The same tendency was shown, as expected, by positive controls which received mutagenic doses of ultraviolet irradiation. We concluded that the most reasonable interpretation of these observations is that mild stress increases the genomic rate of mutation. This appears to be the first time that this phenomenon has been noticed in eukaryotes. The response might be adaptive because lineages in which higher mutation rates are elicited by stress can be favourably selected through the production of a few mutants which are fortuitously well adapted to the stressful environment. Other interpretations are not excluded, however. Regardless of the mechanism involved, the elevation of mutation rates under stress will affect the rate of evolutionary response to environmental change and also the maintenance of sexuality.
Trisomy 16 is frequently found confined to the placenta (confined placental mosaicism (CPM)), with a structurally normal fetus. In some cases of trisomy 16, the fetus has uniparental disomy for chromosome 16 (UPD16) which is associated with intrauterine growth restriction (IUGR) and fetal anomalies. We report a case of apparent confined placental mosaicism for trisomy 16, using standard cytogenetic techniques, but with multiple fetal abnormalities including congenital diaphragmatic hernia in which there was no evidence of UPD in the disomic tissues examined. Subsequent examination of fetal tissues using fluorescent in situ hybridization (FISH) demonstrated low levels of mosaicism for trisomy 16 in all the tissues examined. The use of FISH permits identification of mosaicism which conventional techniques may not identify.
Between 22 January and 4 April 1997, 467 hepatitis A cases were reported to the New South Wales Health Department, Australia. To identify the cause of the outbreak, we conducted a matched case-control study, and an environmental investigation. Among 66 cases and 66 postcode-matched controls, there was a strong association between illness and consumption of oysters (adjusted odds ratio 42; 95 % confidence interval 5-379). More than two-thirds of cases reported eating oysters, including one third of cases and no controls who reported eating oysters in the Wallis Lake area. A public warning was issued on 14 February, and Wallis Lake oysters were withdrawn from sale. Hepatitis A virus was subsequently identified in oyster samples taken from the lake. Hepatitis A virus poses a special risk to consumers who eat raw oysters because it can survive for long periods in estuaries and cause severe disease.