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R Atkins

Publications and source records attributed to R Atkins.

At least 19 recordsLinked to original sources
PubMed2005

Evidence for TeV gamma-ray emission from a region of the galactic plane.

Gamma-ray emission from a narrow band at the galactic equator has previously been detected up to 30 GeV. We report evidence for a TeV gamma-ray signal from a region of the galactic plane by Milagro, a large-field-of-view water Cherenkov detector for extensive air showers. An excess with a significance of 4.5 standard deviations has been observed from the region of galactic longitude l E (40 degrees, 100 degrees) and latitude /b/ < 5 degrees. Under the assumption of a simple power law spectrum, with no cutoff in the EGRET-Milagro energy range, the measured integral flux is phi gamma(>3.5 TeV) = (6.4 +/- 1.4 +/- 2.1) x 10(-11) cm(-2) s(-1) sr(-1). This flux is consistent with an extrapolation of the EGRET spectrum between 1 and 30 GeV in this galactic region.

Journal Article↗
PubMed2005

A new Mother-to-Infant Bonding Scale: links with early maternal mood.

Some mothers find it hard to relate to their new baby, and such failure may have long-term effects on the infant. This has been a neglected area of research. A new simple 8 item self-rating mother-to-infant bonding questionnaire has been designed to assess the feelings of a mother towards her new baby. A principal components and reliability analysis demonstrated an alpha score of 0.71. One hundred and sixty two women filled in the Kennerley Blues Scale, the Edinburgh Postnatal Depression Scale (EPDS) the Highs Scale and the new Mother to Infant Bonding Scale on day 3 postpartum. Twelve weeks later they were sent the EPDS and the Bonding scales again. One hundred and forty four returned all questionnaires. There was a strong correlation between the Bonding scores at 3 days and at 12 weeks (r(s)=0.54 p<0.001). Multiple regression analysis showed that those with raised Blues scores had worse, and those with raised Highs scores had better bonding at 3 days. Those with raised EPDS scores at 3 days (13 and over) had worse bonding scores in the "first few weeks" (median 4 versus 1, p = 0.028), as recalled at 12 weeks. This simple questionnaire is acceptable for use with mothers and gives significant correlations with their early mood.

Adult↗
PubMed2001

The Microcystis cyanobacteria bloom in the Swan River--February 2000.

In February 2000 the Swan-Canning estuary in Western Australia experienced a record bloom of the toxic cyanobacteria Microcystis aeruginosa. At its height, concentrations of M. aeruginosa reached integrated water column cell counts of 15,000/ml and formed bright green scums in sheltered bays, where counts of 130 million cells/ml were recorded. Due to public health concerns parts of the river were closed from 10 to 22 February 2000. Two unseasonably large summer rain events in early and late January 2000 created conditions for the bloom. Freshwater runoff, estimated at 270 GL, was enough to fill the Swan-Canning estuary five times over and brought with it high levels of nutrients, mainly nitrogen (> 2.0 mg/L TN) and phosphorus (> 0.15 mg/L TP). A number of methods to reduce bloom accumulations were tried, including an attempt to increase the salinity of the surface water above the critical 10 ppt level for Microcystis; using a bentonite clay and poly-aluminium chloride mixture to flocculate and sink the algae; and sucking up scums using oil spill equipment. Over 900 tonnes of M. aeruginosa were removed and safely disposed using sewage treatment facilities. The bloom collapsed when the freshwater flush subsided and seawater intrusion from the Indian Ocean re-established itself, raising the salinities above the tolerance of Microcystis.

Environmental Monitoring↗
PubMed2000

Evidence for TeV Emission from GRB 970417a.

Milagrito, a detector sensitive to very high energy gamma rays, monitored the northern sky from 1997 February through 1998 May. With a large field of view and a high duty cycle, this instrument was well suited to perform a search for TeV gamma-ray bursts (GRBs). We report on a search made for TeV counterparts to GRBs observed by BATSE. BATSE detected 54 GRBs within the field of view of Milagrito during this period. An excess of events coincident in time and space with one of these bursts, GRB 970417a, was observed by Milagrito. The excess has a chance probability of 2.8x10-5 of being a fluctuation of the background. The probability for observing an excess at least this large from any of the 54 bursts is 1.5x10-3. No significant correlations were detected from the other bursts.

Journal Article↗
PubMed2000

Carotid artery intima-medial thickness is increased in chronic renal failure.

1. Chronic renal failure (CRF) is associated with rapidly progressive atherosclerotic vascular disease. In the present study, carotid arterial intima-medial thickness (IMT) was assessed in a large cohort of patients with CRF and matched controls and related to risk factors. 2. A total of 159 subjects with CRF (serum creatinine > or =0.40 mmol/L) aged > 50 years (mean (+/-SD) 63.8+/-7.7 years) and 159 healthy controls matched for age, sex and smoking status were studied. 3. The IMT was determined using B-mode ultrasound measurements of the far wall of both common carotid arteries and presented as the mean IMT. Fasting plasma homocysteine (tHcy) was measured in the CRF group. 4. Intima-medial thickness was significantly greater in CRF patients than controls (0.89+/-0.17 vs 0.73+/-0.13 mm, respectively) after matching for age, sex and smoking status. Heart rate and pulse pressure were also significantly increased. The tHcy was increased two-fold in the CRF group (27.7+/-11.3 micromol/L; normal < 13.0 micromol/L) and did not correlate with carotid IMT. 5. Compared with controls after adjusting for traditional risk factors, patients with CRF exhibit significantly increased IMT.

Blood Pressure↗
PubMed1999

TeV Observations of Markarian 501 with the Milagrito Water Cerenkov Detector.

The Milagrito water Cerenkov detector near Los Alamos, New Mexico, was operated as a sky monitor at energies of a few TeV between 1997 February and 1998 May, including the period of the strong, long-lasting 1997 flare of Markarian 501. Milagrito served as a test run for the full Milagro detector. An event excess with a significance of 3.7 sigma from Markarian 501 was observed, in agreement with expectations.

Journal Article↗
PubMed1998

Local regulation of macrophage subsets in the adult rat testis: examination of the roles of the seminiferous tubules, testosterone, and macrophage-migration inhibitory factor.

In the adult rat testis, macrophages belong to one of two subsets differentiated by expression or lack of expression of the resident macrophage surface antigen recognized by monoclonal antibody ED2. Local regulation of the testicular macrophage subsets was investigated in normal and 4-wk experimentally cryptorchid adult rats with and without s.c. testosterone implants (T-implants). Macrophage subsets ED2(+) (resident-type) and ED2(-) (monocyte-like) were identified immunohistochemically and counted in perfusion-fixed frozen testis sections. Depletion of the spermatogenic cells by cryptorchidism had no effect on testicular macrophage numbers. Inhibition of Leydig cell and seminiferous tubule function by low-dose (3 cm) T-implants caused a 40% reduction in ED2(+) resident macrophages in both scrotal and abdominal testes. High-dose (24 cm) T-implants, which inhibit Leydig cell function while maintaining normal seminiferous tubule function, also reduced the number of resident macrophages by approximately 40%, although this reduction was at least partially prevented in the abdominal testes. In the scrotal testis only, the ED2(-) monocyte/macrophage subset was significantly reduced in number by low-dose, but not high-dose, T-implants. The concentration of the Leydig cell-secreted cytokine macrophage-migration inhibitory factor (MIF) in testicular fluid was reduced by cryptorchidism, but not by the T-implants. When data from all experimental groups were combined, ED2(+) resident macrophage numbers showed a significant positive correlation with parameters of Leydig cell function (serum LH and testicular testosterone levels) but a negative correlation with MIF levels. This study indicates that Leydig cells regulate testicular macrophage numbers directly, rather than via an effect upon the seminiferous epithelium, in the adult rat testis. The data also suggest that testosterone and MIF play only a minor role, if any, in this regulation.

Animals↗
PubMed1994

Leukocyte populations of the adult rat testis following removal of the Leydig cells by treatment with ethane dimethane sulfonate and subcutaneous testosterone implants.

The influence of the Leydig cells on the leukocyte population of the testis was investigated. Leydig cells were destroyed by ethane dimethane sulfonate (EDS) treatment in adult male rats, with or without low-dose s.c. testosterone implants to prevent Leydig cell recovery. Leukocytes were counted in perfusion-fixed frozen testis sections, by use of cell-specific monoclonal antibodies (mAbs) with immunoperoxidase detection, or toluidine blue staining. The majority (81%) of testicular leukocytes (OX1+) were immunopositive for the resident macrophage-specific mAb, ED2, and/or the monocyte/macrophage/dendritic cell mAb, ED1. The remaining leukocytes were principally T lymphocytes (R73+). B lymphocytes (OX33+) and metachromatic mast cells were not observed in the normal testis. Treatment with EDS caused a transient increase in ED1+, ED2+, and R73+ cell numbers in the testis, although other evidence of an inflammatory reaction, such as increases in major histocompatibility complex class II antigen, interleukin-2 receptor expression, or capillary permeability, were not observed. At 21 days after EDS treatment, there was a significant decline in macrophage numbers (to approximately 50% of control testis), and T lymphocytes returned to pretreatment levels. After Leydig cell recovery (41 days after treatment), macrophages also returned to pretreatment levels in EDS-treated rats, but remained reduced in EDS-treated animals with testosterone implants. In addition, EDS treatment stimulated a progressive increase in intertubular mast cells, which was significantly inhibited in the testosterone-implanted rats. The data indicate that numbers of testicular macrophages and mast cells, but not of lymphocytes, within the adult rat testis are directly or indirectly regulated by the Leydig cells.

Animals↗
PubMed1992

Interleukin 1 alpha and beta production by cells isolated from membranes around aseptically loose total joint replacements.

Aseptic loosening of joint prostheses is accompanied by local osteolysis. To determine whether local production of interleukin 1 might contribute to such lysis, the number of interleukin 1 secreting cells in the pseudosynovial membrane surrounding prostheses was measured. Interleukin 1 alpha and beta secreting cells were identified by ELISPOT, a sensitive cytokine secreting assay. The proportion of interleukin 1 beta secreting cells in pseudosynovial membrane was comparable with the proportion occurring in the synovium of patients with rheumatoid arthritis and higher than that in normal subjects and patients with osteoarthritis. The proportion of interleukin 1 alpha producing cells was higher in pseudosynovial membrane than in diseased synovium. Overall, higher numbers of interleukin 1 beta than interleukin 1 alpha secreting cells were detected. A correlation was observed between the number of cells in pseudosynovial membrane producing interleukin 1 beta and those producing interleukin 1 alpha. When divided into area of origin, tissue samples from the femoral area contained a higher proportion of interleukin 1 beta producing cells than tissue in the acetabular or capsular regions, though due to variance within each group this difference did not reach significance.

Aged↗
PubMed1991

Family adaptation to AIDS: a comparative study.

In this study the McCubbin stress and coping model was used as a theoretical framework to compare the differences in family adaptation to AIDS and to other terminal illnesses. The non-probability convenience sample consisted of 26 families of AIDS patients and 26 of hospice patients with other terminal illnesses. The Family Inventory of Life Events and Changes was used to measure the number of stressful events experienced by the family since diagnosis and the Family Adaptation to Medical Stressors Questionnaire measured role flexibility. Families of AIDS patients had significantly more stress, more rules prohibiting emotional expression, lower trust levels, and more illness anxiety than the other families.

Acquired Immunodeficiency Syndrome↗
PubMed1990

A comparison of the acute effects of subcutaneous and intranasal calcitonin.

1. We studied the acute effects of intranasal and subcutaneous calcitonin in 40 patients with active Paget's disease of bone. Patients received a single dose of either 400 units of calcitonin delivered as a nasal spray, or 1, 10 or 100 units of subcutaneous calcitonin, or placebo. 2. Subcutaneous salmon calcitonin, administered at doses of 1, 10 and 100 units to nine patients with Paget's disease of bone, induced a dose-dependent fall in the serum calcium. This calcium-lowering effect was not seen with a second group of nine patients receiving placebo. 3. The lower doses of calcitonin had significant effects, and these were more pronounced in patients with lower rates of bone turnover. 4. Four hundred units of calcitonin administered as a nasal spray induced effects qualitatively similar to those seen with subcutaneous calcitonin, with an efficacy equivalent to approximately 30 units of subcutaneous calcitonin. 5. We conclude that the bioequivalence of calcitonin given by intranasal insufflation is low compared with its parenteral administration. The intranasal route may be more appropriate for managing patients with disorders associated with low bone turnover.

Administration, Intranasal↗
PubMed1990

Assessment of broadband ultrasound attenuation in the os calcis in vitro.

1. We have examined the relationship between the attenuation of broadband ultrasound in the os calcis in vitro and its bone mineral density measured by quantitative computed tomography and by physical density. 2. Broadband ultrasound attenuation was found to correlate closely with physical density (r = 0.85, P less than 0.0001), but the correlation was less than that observed between quantitative computed tomography and physical density (r = 0.92, P less than 0.0001). Measurements of broadband ultrasound attenuation and quantitative computed tomography were significantly correlated (r = 0.80, P less than 0.0001). 3. Partial correlation analysis showed a significant relationship between broadband ultrasound attenuation and bone density, but when the effect of physical density was taken into account no significant correlation was found between broadband ultrasound attenuation and quantitative computed tomography (r = 0.08, not significant). 4. Broadband ultrasound attenuation in three prospective amputees showed a high degree of concordance between measurements in vivo and in vitro, with no interference by surrounding soft tissues. 5. The correlation between physical density and broadband ultrasound attenuation was independent of quantitative computed tomography, suggesting that the technique measures aspects of density which differ from its mineral density. Broadband ultrasound attenuation holds promise as a reproducible, rapid, radiation-free assessment of skeletal status.

Aged↗
PubMed1987

Hepatitis B and renal transplantation.

Renal transplantation in HBsAg+ chronic carriers has a relative low risk of progressive liver disease, with mortality associated with liver disease at 7%. In contrast, HBsAg+ recipients who acquired their disease in the early posttransplant period had a mortality of 60%. HBeAg-positive patients who remain persistently positive are a subgroup with a poor prognosis and should not be offered a renal transplant.

Adult↗
PubMed1985

De-novo anti-GBM-antibody-induced glomerulonephritis in a renal transplant.

We report a case of de-novo anti-glomerular basement membrane antibody induced glomerulonephritis (anti-GBM GN) in a renal cadaveric transplant. The 52 year old male patient had developed end-stage renal failure secondary to malignant hypertension. His initial renal transplant lost function within two months because of severe allograft rejection without evidence of anti-glomerular basement membrane (anti-GBM) antibody formation. Eight months after his second cadaveric transplant he developed the nephrotic syndrome. This was followed by a rapid deterioration in graft function associated with the development of diffuse proliferative glomerulonephritis with 100% crescent formation. Linear staining of the GBM with IgG and C3 and the presence of circulating anti-GBM antibodies confirmed the anti-GBM antibody etiology of the glomerular lesion. Thus anti-GBM antibody induced glomerulonephritis can occur de-novo in a transplanted kidney despite routine immunosuppression. This represents either coincidental autoantibody production after transplantation or specific alloantibody production, stimulated by the introduction, by transplantation, of GBM neoantigens.

Antibodies↗