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Biomedical subjects

H Evans

Publications and source records attributed to H Evans.

At least 19 recordsLinked to original sources
PubMed2006

Plasma concentrations of parathyroid hormone-related protein in dogs with potential disorders of calcium metabolism.

The plasma concentrations of total calcium, ionised calcium, albumin, parathyroid hormone and parathyroid hormone-related protein (PTHrp) were measured in 25 dogs with lymphoma, nine dogs with primary hyperparathyroidism and seven dogs with adenocarcinoma of the apocrine gland of the anal sac. Plasma total calcium, ionised calcium, albumin and parathyroid hormone-related protein were measured in 18 clinically normal control dogs. The concentration of PTHrp was high in 12 of the 14 dogs that were hypercalcaemic because of an underlying malignancy but was within the reference range in all the control dogs, in the 17 normocalcaemic dogs with lymphoma and in the seven dogs which were hypercalcaemic because of a parathyroid adenoma.

Adenocarcinoma↗
PubMed2006

Cervical screening in HIV-positive women: characteristics of those who default and attitudes towards screening.

OBJECTIVES: To determine the characteristics of HIV-positive women who undergo cervical screening and to identify negative attitudes and experiences of these women to screening and the factors associated with these. METHODS: We compared the Royal Free Cohort data from 59 newly diagnosed HIV-infected women, 31 of whom did and 28 of whom did not attend for cervical screening in 2001, and from 227 women under active cervical screening follow-up (at least one cervical screen since June 2001) and 88 HIV-infected women lost to follow-up (not screened since January 2001). Attitudes to screening were investigated with the aid of a questionnaire given to all women attending clinic who had had a previous colposcopy. RESULTS: Of the 59 newly HIV diagnosed women, 31 (53%) underwent cervical screening. These 31 women were more likely to be heterosexual (100 vs 89%, P=0.05), to have lower median viral loads (< 50 vs 3210 HIV-1 RNA copies/mL) and to be receiving antiretrovirals (ARVs) (74 vs 54%, P=0.1) than those not screened. Of the 315 women who had at least one screen, 72% returned for further follow-up. There were no differences in age or ethnicity between these groups. Those under active follow-up had a higher CD4 count (P=0.04) and lower viral load (P=0.0001) at their last visit. They were also more likely to be on highly active antiretroviral therapy (HAART) (68 vs 52%, P=0.006). A total of 78 of 104 questionnaires (75%) were returned. Women participating in the questionnaire study were mainly of back ethnicity (68%), did not speak English as their first language (59%) and were taking ARVs (76%). Most agreed that regular smears and colposcopy were valuable. Women of white ethnicity, and those speaking English as a first language, were more likely to dislike colposcopy compared with those of nonwhite ethnicity (87 vs 25%, respectively, P=0.0007) and not speaking English as a first language (74 vs 26%, respectively, P=0.002). Those of white ethnicity were more likely to find smears and colposcopy painful (60 and 73%) compared with those of black ethnicity (46 and 51%, P=0.47 and 0.28, respectively). CONCLUSIONS: Our results suggest that women on HAART with better disease control, older women, and those of black African ethnicity are more likely to take up cervical screening. Cervical screening experience varies by ethnicity and language.

Adult↗
PubMed2005

Hyperparathyroidism in dogs with hyperadrenocorticism.

OBJECTIVES: To assess the effect of canine hyperadrenocorticism (HAC) on parathyroid hormone (PTH), phosphate and calcium concentrations. METHODS: PTH concentrations and routine biochemical parameters were measured in 68 dogs with HAC. Ionised calcium was measured in 28 of these dogs. The results obtained were compared with an age- and weight-matched group of 20 hospital patients that did not show signs of HAC. RESULTS: There were significant differences between the PTH, phosphate, alkaline phosphatase, creatinine and albumin concentrations between the two groups. Total and ionised calcium concentrations were not significantly different. Most of the dogs (92 per cent) with HAC had PTH concentrations that were greater than the reference range (10 to 60 pg/ml), and in 23 dogs they were greater than 180 pg/ml. There were significant positive correlations between the PTH and basal cortisol, post-adrenocorticotropic hormone (ACTH) cortisol and alkaline phosphatase concentrations, and also the phosphate and post-ACTH cortisol concentrations. CLINICAL SIGNIFICANCE: Adrenal secondary hyperparathyroidism is a cause of increased PTH concentrations and may be associated with abnormalities in calcium and phosphate metabolism in dogs with HAC. The findings of this study could explain why canine HAC may cause clinical signs such as calcinosis cutis that are associated with altered calcium metabolism.

Adrenocortical Hyperfunction↗
PubMed2005

Canine hyperadrenocorticism: effects of trilostane on parathyroid hormone, calcium and phosphate concentrations.

OBJECTIVES: To determine the effects of treating canine hyperadrenocorticism (HAC) on parathyroid hormone (PTH), calcium and phosphate concentrations in dogs. METHODS: Serum calcium, phosphate and PTH concentrations were analysed in 22 dogs with HAC before treatment with trilostane and at a median of 210 days after commencing treatment. Pretreatment data were compared with data from an age- and weight-matched group of hospitalised patients, and post-treatment data were compared with pretreatment data. RESULTS: PTH and phosphate concentrations were significantly higher in dogs with HAC compared with control dogs. PTH concentrations reduced significantly with treatment, such that there was no longer a difference between the HAC and control groups. Phosphate concentrations also reduced significantly with treatment but there was still a significant difference between those in dogs with HAC and control dogs. Despite no significant difference between calcium concentrations in the pretreatment HAC and control groups, calcium concentrations increased significantly with treatment. CLINICAL SIGNIFICANCE: These results show that adrenal secondary hyperparathyroidism resolves with treatment and suggest that increased calcium and phosphate levels have a role in its pathogenesis.

3-Hydroxysteroid Dehydrogenases↗
PubMed2004

TNFalpha-stimulated gene product (TSG-6) and its binding protein, IalphaI, in the human intervertebral disc: new molecules for the disc.

Inflammation and irritation of the nerve roots has been indicated as an important factor in the pain associated with symptomatic disc herniations. Tumour necrosis factor alpha (TNFalpha) is now believed to be involved in this pathway. TNFalpha causes connective tissue cells in culture to synthesise a glycoprotein, TNFalpha-stimulated gene-6 (TSG-6). TSG-6 is found in inflammatory diseases of related connective tissues, such as articular cartilage in rheumatoid arthritis, but is not present in unaffected individuals. In order to determine if TSG-6 occurred in intervertebral disc (and cartilage endplate), we have investigated the presence of TSG-6 and its binding protein, inter-alpha-inhibitor (IalphaI), in 58 herniated and 15 non-herniated discs. Immunostaining for the cytokines, IL-1alpha, IL-1beta and TNFalpha, has also been carried out. We have demonstrated that both TSG-6 and IalphaI occur commonly in human intervertebral disc matrix with at least some TSG-6 in 98% of discs studied and IalphaI in all of them. Staining for TSG-6 was greatest in herniated discs, particularly close to blood vessels. IalphaI immunostaining was frequently widespread throughout the disc but there was little in the cartilage endplate. It has been proposed that these molecules have widespread effects, including extracellular matrix stabilisation, down-regulation of the protease network and reduction of inflammation. Hence, the occurrence of TSG-6 and IalphaI in disc tissue could have implications in the aetiopathogenesis and future therapeutics of intervertebral disc disease.

Adolescent↗
PubMed2004

Radiation-induced malignancies following radiotherapy for breast cancer.

With advances in diagnosis and treatment, breast cancer is becoming an increasingly survivable disease resulting in a large population of long-term survivors. Factors affecting the quality of life of such patients include the consequences of breast cancer treatment, which may have involved radiotherapy. In this study, we compare the incidence of second primary cancers in women who received breast radiotherapy with that in those who did not (non-radiotherapy). All women studied received surgery for their first breast cancer. Second cancers of the lung, colon, oesophagus and thyroid gland, malignant melanomas, myeloid leukaemias and second primary breast cancers were studied. Comparing radiotherapy and non-radiotherapy cohorts, elevated relative risks (RR) were observed for lung cancer at 10-14 years and 15 or more (15+) years after initial breast cancer diagnosis (RR 1.62, 95% confidence interval [CI] 1.05-2.54 and RR 1.49, 95% CI 1.05-2.14, respectively), and for myeloid leukaemia at 1-5 years (RR 2.99, 95% CI 1.13-9.33), for second breast cancer at 5-10 years (RR 1.34, 95% CI 1.10-1.63) and 15+ years (RR 1.26, 95% CI 1.00-1.59) and oesophageal cancer at 15+ years (RR 2.19, 95% CI 1.10-4.62).

Breast Neoplasms↗
PubMed2004

Bounding the risk of crew loss following orbital debris penetration of the International Space Station at assembly stages 1J and 1E.

Orbital debris impacts on the International Space Station occur frequently. To date, none of the impacting particles has been large enough to penetrate manned pressurized volumes. We used the Manned Spacecraft Crew Survivability code to evaluate the risk to crew of penetrations of pressurized modules at two assembly stages: after Flight 1J, when the pressurized elements of Kibo, the Japanese Experiment Module, are present, and after Flight 1E, when the European Columbus Module is present. Our code is a Monte-Carlo simulation of impacts on the Station that considers several potential event types that could lead to crew loss. Among the statistics tabulated by the program is the probability of death of one or more crew members in the event of a penetration, expressed as the risk factor, R. This risk factor is dependent on details of crew operations during both ordinary circumstances and decompression emergencies, as well as on details of internal module configurations. We conducted trade studies considering these procedure and configuration details to determine the bounds on R at the 1J and 1E stages in the assembly sequence. Here we compare the R-factor bounds, and procedures could that reduce R at these stages.

Accident Prevention↗
PubMed2003

Multiple primary tumours following head and neck cancer in southern England during 1961-98.

BACKGROUND: Successful initial treatment of oral and oro-phayngeal cancer has led to the emergence of second primary tumours (SPTs). Population data are meagre. METHODS: Occurrence of multiple primary cancers following a malignancy in a head and neck site was computed using data from a population-based cancer registry covering a population of 14 million. RESULTS: Among 59,958 subjects reported to the registry, 5.5% males and 3.6% females developed a second primary cancer. At the sites studied, a total of 2771 second primary cancers were found, compared with an expected number of 2341. The standardised incidence ratio (SIR) for contracting a new primary cancer was 1.14 (95% CI=1.09-1.19) for men and 1.34 (95% CI=1.24-1.44) for women. There was a significantly increased risk for a second cancer in most of the upper aerodigestive tract sites that are generally regarded as tobacco associated, with an SIR for subsequent oral cancer of 5.56 in men and 15.31 in women. Subjects first detected with a pharyngeal cancer experienced the highest SIR for a subsequent tumour. Excluding tobacco-associated sites, the risk of a subsequent cancer was not significantly raised in either sex (SIR 0.87 (95% CI 0.81-0.93) for men; SIR 0.99 (95% CI 0.90-1.09) for women). CONCLUSIONS: The relative risk for multiple primary cancer was higher in younger subjects, those detected with a head and neck cancer during the 1990s as compared with earlier decades of the study, and among patients who received radiotherapy for their first tumour. By 20 years from the time of the first head and neck cancer, we estimate that approximately 30% of male patients and 20% of female patients will have developed an SPT.

Age Factors↗
PubMed2001

Immunohistochemical detection of Schwann cells in innervated and vascularized human intervertebral discs.

STUDY DESIGN: The ingrowth of nerves, blood vessels, and Schwann cells into human intervertebral discs was examined using immunohistochemistry for cell-type-specific markers. OBJECTIVES: To determine whether Schwann cells may contribute to disc innervation, and to assess the relation between disc innervation and vascularization. SUMMARY OF BACKGROUND DATA: Intervertebral disc degeneration was associated previously with ingrowth of blood vessels and nerves. Schwann cells are known to play an important role in regulating nerve growth and survival in other tissues, but they have not been examined in human pathologic intervertebral discs. METHODS: Serial sections of human intervertebral discs were immunostained for the neuronal markers (neurofilament 200, peripherin, protein gene product 9.5), for the Schwann cell marker (glial fibrillary acidic protein), and for the endothelial cell marker (CD34). RESULTS: Glial fibrillary acidic protein-immunopositive cells colocalized with nerves in degenerate discs, but were absent or rarely observed in nondegenerate, aneural discs. These also were seen in the disc matrix, independently of nerves. Much of the nerve and Schwann cell ingrowth was found in vascularized areas of disc tissue, where the lamellar structure of the anulus fibrosus was disrupted. Blood vessels were observed deeper into the discs than nerves or Schwann cells. CONCLUSIONS: The appearance of glial fibrillary acidic protein-immunopositive cells in diseased intervertebral discs was closely associated with nerve ingrowth. This novel finding suggests that Schwann cells have a role to play in regulating disc innervation and nerve function in the disc. Because blood vessels were observed furthermost into the disc, it is possible that degenerate disc vascularization occurs before innervation.

Adolescent↗
PubMed2001

Use of endogenous ACTH concentration and adrenal ultrasonography to distinguish the cause of canine hyperadrenocorticism.

Twenty-nine dogs were diagnosed with hyperadrenocorticism (HAC). A single determination of endogenous plasma adrenocorticotropic hormone (ACTH) and adrenal ultrasonography were used in a prospective study to differentiate between pituitary-dependent HAC (PDH) and adrenal-dependent HAC (ADH). In 27 out of the 29 dogs (93 per cent), both endogenous plasma ACTH concentrations and adrenal ultrasonography indicated the same cause of HAC. Twenty-one of the 29 cases (72 per cent) were shown to be pituitary-dependent; all had plasma ACTH concentrations of greater than 28 pg/ml (reference range 13 to 46 pg/ml) and both adrenal glands were ultrasonographically of similar size and of normal shape. All 21 cases responded well to mitotane therapy. Six cases (21 per cent) were shown to be adrenal-dependent; all had plasma ACTH concentrations below the limit of the assay (<5 pg/ml) and the presence of an adrenal mass on ultrasonography. The sensitivity and specificity of adrenal ultrasonography and endogenous ACTH determinations to identify the cause of HAC were demonstrated to be 100 per cent and 95 per cent, respectively, for ADH. These discriminatory tests are more accurate than published figures for dexamethasone suppression testing.

Adrenal Glands↗
PubMed2000

Measurement of the W-->taunu production cross section in pp collisions at square root s=1.8 TeV.

We report on a measurement of sigma(pp-->W+X)B(W-->taunu) in pp collisions at sqrt[s]=1.8 TeV at the Fermilab Tevatron. The measurement is based on an integrated luminosity (lum) of 18 pb-1 of data collected with the D0 detector during 1994-1995. We find that sigma(pp-->W+X)B(W-->taunu)=2.22+/-0.09 (stat)+/-0. 10 (syst)+/-0.10 (lum) nb. Lepton universality predicts that the ratio of the tau and electron electroweak charged current couplings to the W boson, gWtau/gWe, be unity. We find gWtau/gWe=0.980+/-0.031, in agreement with lepton universality.

Journal Article↗
PubMed2000

Probing Balitsky-Fadin-Kuraev-Lipatov dynamics in the dijet cross section at large rapidity intervals in pp collisions at sqrt[s]=1800 and 630 GeV.

Inclusive dijet production at large pseudorapidity intervals (Deltaeta) between the two jets has been suggested as a regime for observing Balitsky-Fadin-Kuraev-Lipatov (BFKL) dynamics. We have measured the dijet cross section for large Deltaeta in pp collisions at sqrt[s]=1800 and 630 GeV using the D0 detector. The partonic cross section increases strongly with the size of Deltaeta. The observed growth is even stronger than expected on the basis of BFKL resummation in the leading logarithmic approximation. The growth of the partonic cross section can be accommodated with an effective BFKL intercept of alphaBFKL(20 GeV)=1.65+/-0.07.

Journal Article↗
PubMed2000

Early evaluation of tumour metabolic response using [18F]fluorodeoxyglucose and positron emission tomography: a pilot study following the phase II chemotherapy schedule for temozolomide in recurrent high-grade gliomas.

Quantitation of metabolic changes in tumours may provide an objective measure of clinical and subclinical response to anticancer therapy. This pilot study assesses the value of quantitation of metabolic rate of glucose (MRGlu) measured in mmol min(-1) ml(-1) to assess early subclinical response to therapy in a relatively non-responsive tumour. Nine patients receiving the CRC Phase II study schedule of temozolomide were assessed with [18F]fluorodeoxyglucose ([18F]FDG) dynamic positron emission tomography (PET) scans prior to and 14 days after treatment with temozolomide given as 750-1000 mg m(-2) over 5 days every 28 days. Tumour MRGlu was calculated and compared with objective response at 8 weeks. Pretreatment MRGlu was higher in responders than non-responders. The responding patient group had a greater than 25% reduction in MRGlu in regions of high focal tumour uptake (HFU). Whole tumour changes in MRGlu did not correlate with response. Percentage change in HFU standardized uptake value (SUV) did discriminate the responding from the non-responding patients, but not as well as with MRGlu. Large differences also occurred in the normal brain SUV following treatment. Thus, MRGlu appeared to be a more sensitive discriminator of response than the simplified static SUV analysis. Changes in MRGlu may reflect the degree of cell kill following chemotherapy and so may provide an objective, quantitative subclinical measure of response to therapy.

Adult↗
PubMed2000

Muscle volume, MRI relaxation times (T2), and body composition after spaceflight.

Postflight changes in muscle volume, calf muscle transverse relaxation time, and total body composition were measured in 4 crewmembers after a 17-day mission and in 14-16 crewmembers in multiple shuttle/Mir missions of 16- to 28-wk duration. During the 17-day mission, all muscle regions except the hamstrings significantly decreased 3-10% compared with baseline. During the shuttle/Mir missions, there were significant decreases in muscle volume (5-17%) in all muscle groups except the neck. These changes, which reached a new steady state by 4 mo of flight or less, were reversed within 30-60 days after landing. Postflight swelling and elevation of calf muscle transverse relaxation time persisted for several weeks after flight, which suggests possible muscle damage. In contrast to the 17-day flight, in which loss in fat, but not lean body mass, was found (25), losses in bone mineral content and lean body mass, but not fat, were seen after the longer shuttle/Mir missions. The percent losses in total body lean body mass and bone mineral content were similar at approximately 3.4-3.5%, whereas the pelvis demonstrated the largest regional bone loss at 13%.

Adult↗
PubMed2000

The use of patient registers to estimate migration.

This article presents information discussed at the recent regional seminars on population statistics. It describes a new data source for estimating internal migration between local and health authorities in England and Wales, discusses the way that the data have been collected and processed, and how limitations in the raw data have been addressed. It then goes on to explain the way that the new internal migration estimates have been used in the calculation of population estimates for local and health authorities. This is a change to the method of estimating migration in the calculation of population estimates.

Censuses↗